Aging biomarkers are a combination of biological parameters to(i)assess age-related changes,(ii)track the physiological aging process,and(iii)predict the transition into a pathological status.Although a broad spectrum...Aging biomarkers are a combination of biological parameters to(i)assess age-related changes,(ii)track the physiological aging process,and(iii)predict the transition into a pathological status.Although a broad spectrum of aging biomarkers has been developed,their potential uses and limitations remain poorly characterized.An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research:How old are we?Why do we get old?And how can we age slower?This review aims to address this need.Here,we summarize our current knowledge of biomarkers developed for cellular,organ,and organismal levels of aging,comprising six pillars:physiological characteristics,medical imaging,histological features,cellular alterations,molecular changes,and secretory factors.To fulfill all these requisites,we propose that aging biomarkers should qualify for being specific,systemic,and clinically relevant.展开更多
The emergence of exotic quantum phenomena in frustrated magnets is rapidly driving the development of quantum many-body physics,raising fundamental questions on the nature of quantum phase transitions.Here we unveil t...The emergence of exotic quantum phenomena in frustrated magnets is rapidly driving the development of quantum many-body physics,raising fundamental questions on the nature of quantum phase transitions.Here we unveil the behaviour of emergent symmetry involving two extraordinarily representative phenomena,i.e.,the deconfined quantum critical point(DQCP)and the quantum spin liquid(QSL)state.Via large-scale tensor network simulations,we study a spatially anisotropic spin-1/2 square-lattice frustrated antiferromagnetic(AFM)model,namely the J1x-J1y-J2 model,which contains anisotropic nearestneighbor couplings J1x,J1y and the next nearest neighbor coupling J2.For small J1y/J1x,by tuning J2,a direct continuous transition between the AFM and valence bond solid phase is observed.With growing J1y/J1x,a gapless QSL phase gradually emerges between the AFM and VBS phases.We observe an emergent O(4)symmetry along the AFM–VBS transition line,which is consistent with the prediction of DQCP theory.Most surprisingly,we find that such an emergent O(4)symmetry holds for the whole QSL–VBS transition line as well.These findings reveal the intrinsic relationship between the QSL and DQCP from categorical symmetry point of view,and strongly constrain the quantum field theory description of the QSL phase.The phase diagram and critical exponents presented in this paper are of direct relevance to future experiments on frustrated magnets and cold atom systems.展开更多
Asia stands out as a priority for urgent biodiversity conservation due to its large protected areas(PAs)and threatened species.Since the 21st century,both the highlands and lowlands of Asia have been experiencing the ...Asia stands out as a priority for urgent biodiversity conservation due to its large protected areas(PAs)and threatened species.Since the 21st century,both the highlands and lowlands of Asia have been experiencing the dramatic human expansion.However,the threat degree of human expansion to biodiversity is poorly understood.Here,the threat degree of human expansion to biodiversity over 2000 to 2020 in Asia at the continental(Asia),national(48 Asian countries),and hotspot(6,502 Asian terrestrial PAs established before 2000)scales is investigated by integrating multiple large-scale data.The results show that human expansion poses widespread threat to biodiversity in Asia,especially in Southeast Asia,with Malaysia,Cambodia,and Vietnam having the largest threat degrees(~1.5 to 1.7 times of the Asian average level).Human expansion in highlands induces higher threats to biodiversity than that in lowlands in one-third Asian countries(most Southeast Asian countries).The regions with threats to biodiversity are present in~75%terrestrial PAs(including 4,866 PAs in 26 countries),and human expansion in PAs triggers higher threat degrees to biodiversity than that in non-PAs.Our findings provide novel insight for the Sustainable Development Goal 15(SDG-15 Life on Land)and suggest that human expansion in Southeast Asian countries and PAs might hinder the realization of SDG-15.To reduce the threat degree,Asian developing countries should accelerate economic transformation,and the developed countries in the world should reduce the demands for commodity trade in Southeast Asian countries(i.e.,trade leading to the loss of wildlife habitats)to alleviate human expansion,especially in PAs and highlands.展开更多
Chirality transformation is a basic,attractive,and important strategy for obtaining enantioenriched products with desired chiral elements.The reported chirality conversion reaction often involves the process from one ...Chirality transformation is a basic,attractive,and important strategy for obtaining enantioenriched products with desired chiral elements.The reported chirality conversion reaction often involves the process from one type of chirality to another one.To better utilize the chirality transformation strategy for obtaining two or more products with different chiral elements in a single reaction,a new method of kinetic resolution accompanied by a chirality transformation protocol is proposed and successfully realized in this study.This process is used for the asymmetric oxidation of phenol compounds along with the kinetic resolution of oxaziridines.A wide scope of products,including axially chiral phenols,oxaziridines,andα-hydroxyl cyclic ketones were smoothly obtained in high levels of yields and enantioselectivities in the developed method.These products can be readily used for the synthesis of various types of chiral ligands,which are potential choices for other catalytic asymmetric reactions.展开更多
We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak noise.We aim to consider a next-to-leading-order approximation for m...We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak noise.We aim to consider a next-to-leading-order approximation for more accurate calculation of the mean exit time by computing large deviation prefactors with the aid of machine learning.More specifically,we design a neural network framework to compute quasipotential,most probable paths and prefactors based on the orthogonal decomposition of a vector field.We corroborate the higher effectiveness and accuracy of our algorithm with two toy models.Numerical experiments demonstrate its powerful functionality in exploring the internal mechanism of rare events triggered by weak random fluctuations.展开更多
The reduction degree of TiO_(2)support is critical to the performances of metal catalysts.In many previous theoretical calculations,only the bridge oxygen vacancy(Ov)was considered as the electron-donating defect on r...The reduction degree of TiO_(2)support is critical to the performances of metal catalysts.In many previous theoretical calculations,only the bridge oxygen vacancy(Ov)was considered as the electron-donating defect on reduced rutile TiO_(2)(r-TiO_(2−x))supports.However,titanium adatoms(Tiad.),oxidized titanium islands(Tiad.On),and acid hydroxyls(ObrH)also exist at the metal/support interface.By conducting density functional theory(DFT)calculations and ab initio molecular dynamics(AIMD)simulations,we compared r-TiO_(2−x)surfaces with Ov,Tiad.,Tiad.On,and ObrH sites loaded with Au nanoparticles(NPs).The results showed the Au NPs were oxygen-phobic but titanium-philic,resulting in wetting of Ov and Tiad.but short contact with Tiad.On and ObrH.The Bader charges of Au NPs(QM)showed a good linear relationship with the ideal number of donating electrons(Ne)from the defective sites(QM=−KeNe+QM,S),demonstrating the intrinsic electron allocation at the interface.The Ov,Tiad.,and Tiad.On exhibited similar slopes(Ke),relatively steeper than that of ObrH.That means in the scope of Au NP charge state,the Tiad.and Tiad.On have a close electron-donating ability with Ov,but the ObrH donates relatively fewer electrons.This linear relationship can be extended approximately to other metals.The higher the metal work function,the steeper the Ke for easier electron donation from defective sites.The stronger the metal oxygen affinity,the more positive the intercept(QM,S).That explains the easy generation of metallic or negative Pt and Au NPs on r-TiO_(2−x),but hard for Cu and Zn in experiment.That provides theoretical guidance for regulating the charge of metal NPs over TiO_(2−x)supports.展开更多
Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso...Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso compound feedstocks.Two strategic modes have been developed for these reactions,which differ in the nature of the stereo-determining steps.The first category deals primarily with the stereoselective desymmetrization of closed-shell radical precursors or functional reagents,whereas the second category achieves desymmetrization by stereoselectively functionalizing open-shell radical species.This mini-review explores the research progress in this growing field,aiming to elucidate mechanistic scenarios related to stereochemical control.Additionally,it offers insights into the challenges and opportunities that lie ahead for further development.展开更多
The reaction of carbonyl-to-imine/hemiaminal conversion in the atmospheric aqueous phase is a critical pathway to produce the light-absorbing N-containing secondary organic compounds(SOC).The formation mechanism of th...The reaction of carbonyl-to-imine/hemiaminal conversion in the atmospheric aqueous phase is a critical pathway to produce the light-absorbing N-containing secondary organic compounds(SOC).The formation mechanism of these compounds has been wildly investigated in bulk solutions with a low ionic strength.However,the ionic strength in the aqueous phase of the polluted atmosphere may be higher.It is still unclear whether and to what extent the inorganic ions can affect the SOC formation.Here we prepared the bulk solution with certain ionic strength,in which glyoxal and ammonium were mixed to mimic the aqueous-phase reaction.Molecular characterization by High-resolution Mass Spectrometry was performed to identify the N-containing products,and the light absorption of the mixtures was measured by ultraviolet-visible spectroscopy.Thirty-nine N-containing compounds were identified and divided into four categories(N-heterocyclic chromophores,high-molecular-weight compounds with N-heterocycle,aliphatic imines/hemiaminals,and the unclassified).It was observed that the longer reaction time and higher ionic strength led to the formation of more N-heterocyclic chromophores and the increasing of the lightabsorbance of the mixture.The added inorganic ions were proposed to make the aqueous phase somewhat viscous so that the molecules were prone to undergo consecutive and intramolecular reactions to form the heterocycles.In general,this study revealed that the enhanced ionic strength and prolonged reaction time had the promotion effect on the lightabsorbing SOC formation.It implies that the aldehyde-derived aqueous-phase SOC would contribute more light-absorbing particulate matter in the industrial or populated area where inorganic ions are abundant.展开更多
The outstanding thermoelectric material, SnSe, is also known for its inferior mechanical properties, which bring great inconvenience for its application in thermoelectric devices. In this work, SnSe bulks were prepare...The outstanding thermoelectric material, SnSe, is also known for its inferior mechanical properties, which bring great inconvenience for its application in thermoelectric devices. In this work, SnSe bulks were prepared via a sequential procedure of high-pressure synthesis (HPS), ball milling, and spark plasma sintering (SPS). The produced polycrystalline samples with a unique microstructure of tightly-bound quasi-equiaxed grains exhibited excellent mechanical properties. The Vickers hardness (HV), compressive strength (σ_(c)), and bending strength (σ_(b)) reached 1.1 GPa, 300 MPa, and 90 MPa, respectively, all of which are far superior to those of ordinary polycrystalline SnSe. Furthermore, the microstructures did not deteriorate thermoelectric performance. This work demonstrated an effective procedure to prepare polycrystalline microstructure-engineered SnSe materials, which not only show advantages in device applications but also shed light on property enhancement for other layer-structured thermoelectric materials.展开更多
Background Mangrove tannins can participate in wetland biogeochemical cycling.However,their fate and dynamics during leaf litter leaching have yet to be elucidated in coastal aquatic environments.Methods By using a si...Background Mangrove tannins can participate in wetland biogeochemical cycling.However,their fate and dynamics during leaf litter leaching have yet to be elucidated in coastal aquatic environments.Methods By using a simulated microcosm experiment,changes in leaf litter mass and tannin compounds,including total phenolics(TP),extractable condensed tannins(ECT),and bound condensed tannins(BCT),were examined in the litters and leachates of four common mangrove species:Kandelia obovata(Ko),Aegiceras corniculatum(Ac),Sonneratia apetala(Sa),and Avicennia marina(Am).Results Leaching caused a notable decline in litter mass,TP,and ECT in the leaf litter of Ko,Ac,Sa,and Am,while BCT increased significantly in Ko and Ac.Loss in foliar TP was higher than in leaf litter mass,and loss in foliar ECT was higher than in TP of Ko and Ac,but Sa showed the opposite result.The temporal changes of TP and ECT concentrations in leachates followed a similar trend,with an initial increase followed by a decrease.ECT dynamics in Ko and Ac leachates correlated with their TP concentrations,while in Sa leachate,the peak ECT occurred 72 h later than its TP peak.The leachate ECT concentrations were highest in Ac,followed by Ko,and significantly lower in Sa.The peak TP and ECT proportions in leachates accounted for 9.2-23.9%and 7.7-9.4%of the total decreases in foliar TP and ECT,respectively.Conclusion During the leaching process,tannins’fate was species-specific,while the dynamics were almost similar.展开更多
We have carried out the Galactic Plane Pulsar Snapshot(GPPS)survey by using the Five-hundred-meter Aperture Spherical radio Telescope(FAST),the most sensitive systematic pulsar survey in the Galactic plane.In addition...We have carried out the Galactic Plane Pulsar Snapshot(GPPS)survey by using the Five-hundred-meter Aperture Spherical radio Telescope(FAST),the most sensitive systematic pulsar survey in the Galactic plane.In addition to more than 500 pulsars already discovered through normal periodical search,we report here the discovery of 76 new transient radio sources with sporadic strong pulses,detected by using the newly developed module for a sensitive single-pulse search.Their small DM values suggest that they all are Galactic rotating radio transients(RRATs).They show different properties in the follow-up observations.More radio pulses have been detected from 26 transient radio sources but no periods can be found due to a limited small number of pulses from all FAST observations.The followup observations show that 16 transient sources are newly identified as being the prototypes of RRATs with a period already determined from more detected sporadic pulses,and 10 sources are extremely nulling pulsars,and 24 sources are weak pulsars with sparse strong pulses.On the other hand,48 previously known RRATs have been detected by the FAST,either during verification observations for the GPPS survey or through targeted observations of applied normal FAST projects.Except for one RRAT with four pulses detected in a session of 5-minute observation and four RRATs with only one pulse detected in a session,sensitive FAST observations reveal that 43 RRATs are just generally weak pulsars with sporadic strong pulses or simply very nulling pulsars,so that the previously known RRATs always have an extreme emission state together with a normal hardly detectable weak emission state.This is echoed by the two normal pulsars J1938+2213 and J1946+1449 with occasional brightening pulses.Though strong pulses of RRATs are very outstanding in the energy distribution,their polarization angle variations follow the polarization angle curve of the averaged normal pulse profile,suggesting that the predominant sparse pulses of RRATs are emitted in the same re展开更多
Mobility restriction measures were the main tools to control the spread of COVID-19,but the extent to which the mobility has decreased remained unsure.We investigated the change in local population mobility and its co...Mobility restriction measures were the main tools to control the spread of COVID-19,but the extent to which the mobility has decreased remained unsure.We investigated the change in local population mobility and its correlation with COVID-19 infections,using 1185 billion aggregated mobile phone data records in nine main cities in China from 10 January to 24 February 2020.The mobility fell by as much as 79.57%compared to the normal days in 2020 and by 58.13%compared to the same lunar period in 2019.The daily incidence of COVID-19 was significantly correlated with local daily mobility(R2=0.77,P<0.001).The instantaneous reproduction number R(t)declined by 3%when mobility was reduced by 10%in the GLM analysis(P<0.05).Our study indicated that the decreased mobility level,driven by a mixture effect of holiday and public health interventions,could substantially reduce the transmission of COVID-19 to a low level.Our study could provide evidence of mobility restriction to control local transmission for other places facing COVID-19 outbreaks or potential next waves.展开更多
Non-antibiotic fungicides are urgently needed due to the potential threat of drug-resistant bacteria to human health.In this research,a novel antibacterial nanoplatform based on CeO_(2)@C-N has been developed to achie...Non-antibiotic fungicides are urgently needed due to the potential threat of drug-resistant bacteria to human health.In this research,a novel antibacterial nanoplatform based on CeO_(2)@C-N has been developed to achieve rapid near-infrared(NIR)laser-induced sterilization.The prepared CeO_(2)@C-N hybrid material exhibited a nanowire-like structure,with dispersed CeO_(2)nanoparticles averaging 5 nm in size within the heterogeneous configuration.X-ray photoelectron spectroscopy(XPS)and Raman spectra revealed that the heterogenous structures have a significant amount of oxygen vacancies and defects.Notably,CeO_(2)@C-N has a narrower band gap than CeO_(2),which allows for broader absorbance extending to the NIR region.With these unique physiochemical properties,CeO_(2)@C-N could inactivate E.coli and MRSA at a low concentration(20 mg/L)under 808 nm NIR laser(1 W/cm^(2))irradiation.The excellent bactericidal activity of CeO_(2)@C-N is attributed to the combination of photodynamic and photo thermal processes,based on its excellent photo-thermal conversion property,detection of reactive oxygen species(ROS)(^(1)O_(2)and·OH)under light irradiation,and scavenger quenching experiment results.This study offers a feasible and efficient way to fabricate a highly effective antibacterial candidate.展开更多
With the rapid development of computer vision,point clouds technique was widely used in practical applications,such as obstacle detection,roadside detection,smart city construction,etc.However,how to efficiently ident...With the rapid development of computer vision,point clouds technique was widely used in practical applications,such as obstacle detection,roadside detection,smart city construction,etc.However,how to efficiently identify the large scale point clouds is still an open challenge.For relieving the large computation consumption and low accuracy problem in point cloud classification,a large scale point cloud classification framework based on light bottle transformer(light-Bot Net)is proposed.Firstly,the two-dimensional(2D)and three-dimensional(3D)feature values of large scale point cloud were extracted for constructing point cloud feature images,which employed the prior knowledge to normalize the point cloud features.Then,the feature images are input to the classification network,and the light-Bot Net network is applied for point cloud classification.It is an interesting attempt to combine the traditional image features with the transformer network.For proving the performance of the proposed method,the large scale point cloud benchmark Oakland 3D is utilized.In the experiments,the proposed method achieved 98.1%accuracy on the Oakland 3D dataset.Compared with the other methods,it can both reduce the memory consumption and improve the classification accuracy in large scale point cloud classification.展开更多
We report on a vortex laser chirped-pulse amplification(CPA)system that delivers pulses with a peak power of 45 TW.A focused intensity exceeding 1019 W/cm2 has been demonstrated for the first time by the vortex amplif...We report on a vortex laser chirped-pulse amplification(CPA)system that delivers pulses with a peak power of 45 TW.A focused intensity exceeding 1019 W/cm2 has been demonstrated for the first time by the vortex amplification scheme.Compared with other schemes of strong-field vortex generation with high energy flux but narrowband vortex-converting elements at the end of the laser,an important advantage of our scheme is that we can use a broadband but size-limited q-plate to realize broadband mode-converting in the front end of the CPA system,and achieve high-power amplification with a series of amplifiers.This method is low cost and can be easily implemented in an existing laser system.The results have verified the feasibility to obtain terawatt and even petawatt vortex laser amplification by a CPA system,which has important potential applications in strong-field laser physics,for example,generation of vortex particle beams with orbital angular momentum,fast ignition for inertial confinement fusion and simulation of the extreme astrophysical environment.展开更多
Background:Mangrove forests are a significant contributor to the global carbon cycle,and the accurate estimation of their gross primary productivity(GPP)is essential for understanding the carbon budget within blue car...Background:Mangrove forests are a significant contributor to the global carbon cycle,and the accurate estimation of their gross primary productivity(GPP)is essential for understanding the carbon budget within blue carbon ecosystems.Little attention has been given to the investigation of spatiotemporal patterns and ecological variations within mangrove ecosystems,as well as the quantitative analysis of the influence of geo-environmental factors on time-series estimations of mangrove GPP.Methods:This study explored the spatiotemporal dynamics of mangrove GPP from 2000 to 2020 in Gaoqiao Mangrove Reserve,China.A leaf area index(LAI)-based light-use efficiency(LUE)model was combined with Landsat data on Google Earth Engine(GEE)to reveal the variations in mangrove GPP using the Mann-Kendall(MK)test and Theil-Sen median trend.Moreover,the spatiotemporal patterns and ecological variations in mangrove ecosystems across regions were explored using four landscape indicators.Furthermore,the effects of six geo-environmental factors(species distribution,offshore distance,elevation,slope,planar curvature and profile curvature)on GPP were investigated using Geodetector and multi-scale geo-weighted regression(MGWR).Results:The results showed that the mangrove forest in the study area experienced an area loss from 766.26 ha in 2000 to 718.29 ha in 2020,mainly due to the conversion to farming,terrestrial forest and aquaculture zones.Landscape patterns indicated high levels of vegetation aggregation near water bodies and aquaculture zones,and low levels of aggregation but high species diversity and distribution density near building zone.The mean value of mangrove GPP continuously increased from 6.35 g C⋅m^(-2)⋅d^(-1) in 2000 to 8.33 g C⋅m^(-2)⋅d^(-1) in 2020,with 23.21%of areas showing a highly and significantly increasing trend(trend value>0.50).The Geodetector and MGWR analyses showed that species distribution,offshore distance and elevation contributed most to the GPP variations.Conclusions:These results provide guideli展开更多
According to the risk management and reputation insurance theory of corporate social responsibility, corporate donations can help a company to repair its reputation after a crisis.This study uses a propensity score ma...According to the risk management and reputation insurance theory of corporate social responsibility, corporate donations can help a company to repair its reputation after a crisis.This study uses a propensity score matching–difference in difference(PSM + DID) methodology to investigate the charitable donation activities of companies that have been subject to regulatory penalties.The analysis of a sample of A-share listed companies in the 2004–2016 period shows that companies significantly increase their charitable donations after regulatory penalties, but this effect weakens over time.Further analysis reveals that non-state-owned companies, companies with higher ownership concentrations, and companies receiving severer penalties are more motivated to make donations after regulatory penalties.By studying the reputation repair behavior of companies that have been subject to regulatory penalties, this study offers further support for the risk management and reputation insurance theory of corporate social responsibility.It also enriches our understanding of companies’ active responses to regulatory penalties and provides insights into companies’ motives for making charitable donations.展开更多
Organic electronics have gained significant attention in the field of biosensors owing to their immense potential for economical,lightweight,and adaptable sensing devices.This review explores the potential of organic ...Organic electronics have gained significant attention in the field of biosensors owing to their immense potential for economical,lightweight,and adaptable sensing devices.This review explores the potential of organic electronics-based biosensors as a revolutionary technology for biosensing applications.The focus is on two types of organic biosensors:organic field effect transistor(OFET)and organic electrochemical transistor(OECT)biosensors.OFET biosensors have found extensive application in glucose,DNA,enzyme,ion,and gas sensing applications,but suffer from limitations related to low sensitivity and selectivity.On the other hand,OECT biosensors have shown superior performance in sensitivity,selectivity,and signal-to-noise ratio,owing to their unique mechanism of operation,which involves the modulation of electrolyte concentration to regulate the conductivity of the active layer.Recent advancements in OECT biosensors have demonstrated their potential for biomedical and environmental sensing,including the detection of neurotransmitters,bacteria,and heavy metals.Overall,the future directions of OFET and OECT biosensors involve overcoming these challenges and developing advanced devices with improved sensitivity,selectivity,reproducibility,and stability.The potential applications span diverse fields including human health,food analysis,and environment monitoring.Continued research and development in organic biosensors hold great promise for significant advancements in sensing technology,opening up new possibilities for biomedical and environmental applications.展开更多
Relativistic outflows often exhibit extreme observational characteristics due to beaming effects, which makes measuring their jet power a challenging task. Although the spectral energy distribution(SED) obtained from ...Relativistic outflows often exhibit extreme observational characteristics due to beaming effects, which makes measuring their jet power a challenging task. Although the spectral energy distribution(SED) obtained from multi-wavelength data can constrain the physical parameters of these jets, accurately estimating the Doppler factor remains difficult. To address this challenge, we assemble a comprehensive sample containing available SEDs of synchrotron and inverse Compton(IC) components, monochromatic luminosity, and broad-line region(BLR) emissions. We employ a parabolic equation to fit the synchrotron radiation SEDs,constraining jet physical parameters within the framework of a one-zone leptonic model. Our study delves into the jet properties and Doppler factor estimations, yielding the following key findings:(1) The fitting results of SED data for the entire sample reveal normal distributions of jet physical parameters for two subclasses of blazars.(2) Correlation analysis demonstrates that synchrotron peak luminosity exhibits a proportional relationship with both the radio and the γ-ray luminosities.(3) We introduce a novel method for estimating Doppler factors, which uncovers discrepancies between Doppler factors from this work and others from different techniques.展开更多
基金supported by the National Natural Science Foundation of China(31730036,31871380,31871382,31930055,31930058,32000500,32022034,32030033,32070730,32130046,3217050247,32150005,32200595,32222024,81730019,81730022,81830014,81921006,81925005,81970426,81971301,81971312,82030041,82061160495,82070805,82071595,82090020,82100841,82120108009,82122024,82125002,82125011,82125012,82130045,82171284,82173061,82173398,82225007,82225015,82225017,82225018,82230047,82230088,82271600,91949106,91949201,92049116,92049302,92049304,92149303,92149306,92157202,92168201,92169102,92249301,92268201)the National Key Research and Development Program of China(2018YFA0800700,2018YFC2000100,2018YFC2000102,2018YFC2002003,2019YFA0110900,2019YFA0801703,2019YFA0801903,2019YFA0802202,2019YFA0904800,2020YFA0113400,2020YFA0803401,2020YFA0804000,2020YFC2002900,2020YFC2008000,2020YFE0202200,2021YFA0804900,2021YFA1100103,2021YFA1100900,2021YFE0114200,2021ZD0202400,2022YFA0806001,2022YFA0806002,2022YFA0806600,2022YFA1103200,2022YFA1103601,2022YFA1103701,2022YFA1103800,2022YFA1103801,2022YFA1104100,2022YFA1104904,2022YFA1303000,2022YFC2009900,2022YFC2502401,2022YFC3602400,2022YFE0118000,2022ZD0213200)+9 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16030302,XDB39000000,XDB39030600)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2020085,2021080)CAS Project for Young Scientists in Basic Research(YSBR-076)the Program of the Beijing Natural Science Foundation(JQ20031)Clinical Research Operating Fund of Central High level hospitals(2022-PUMCHE-001)CAMS Innovation Fund for Medical Sciences(CIFMS)(2022-I2M1-004)Talent Program of the Chinese Academy of Medical Science(2022RC310-10)Research Funds from Health@Inno HK Program launched by Innovation Technology Commission of the Hong Kong Special Administrative Region,Guangdong Basic and Applied Basic Research Foundation(2020B1515020044)Guangzhou Planned Project of Science and Technology(202002020039)the Major Technology Innovation of Hubei Province(2019ACA14
文摘Aging biomarkers are a combination of biological parameters to(i)assess age-related changes,(ii)track the physiological aging process,and(iii)predict the transition into a pathological status.Although a broad spectrum of aging biomarkers has been developed,their potential uses and limitations remain poorly characterized.An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research:How old are we?Why do we get old?And how can we age slower?This review aims to address this need.Here,we summarize our current knowledge of biomarkers developed for cellular,organ,and organismal levels of aging,comprising six pillars:physiological characteristics,medical imaging,histological features,cellular alterations,molecular changes,and secretory factors.To fulfill all these requisites,we propose that aging biomarkers should qualify for being specific,systemic,and clinically relevant.
基金supported by the National Key R&D Program of China(2022YFA1403700)the National Natural Science Foundation of China(NSFC)and the Research Grants Council(RGC)Joint Research Scheme of the Hong Kong Research Grants Council(N-CUHK427/18)+4 种基金the National Natural Science Foundation of China(12141402)supported by the Science,Technology and Innovation Commission of Shenzhen Municipality(ZDSYS20190902092905285)Guangdong Basic and Applied Basic Research Foundation(2020B1515120100)Center for Computational Science and Engineering at Southern University of Science and Technology.S.S.G.was supported by the National Natural Science Foundation of China(11874078 and 11834014)the Dongguan Key Laboratory of Artificial Intelligence Design for Advanced Materials.
文摘The emergence of exotic quantum phenomena in frustrated magnets is rapidly driving the development of quantum many-body physics,raising fundamental questions on the nature of quantum phase transitions.Here we unveil the behaviour of emergent symmetry involving two extraordinarily representative phenomena,i.e.,the deconfined quantum critical point(DQCP)and the quantum spin liquid(QSL)state.Via large-scale tensor network simulations,we study a spatially anisotropic spin-1/2 square-lattice frustrated antiferromagnetic(AFM)model,namely the J1x-J1y-J2 model,which contains anisotropic nearestneighbor couplings J1x,J1y and the next nearest neighbor coupling J2.For small J1y/J1x,by tuning J2,a direct continuous transition between the AFM and valence bond solid phase is observed.With growing J1y/J1x,a gapless QSL phase gradually emerges between the AFM and VBS phases.We observe an emergent O(4)symmetry along the AFM–VBS transition line,which is consistent with the prediction of DQCP theory.Most surprisingly,we find that such an emergent O(4)symmetry holds for the whole QSL–VBS transition line as well.These findings reveal the intrinsic relationship between the QSL and DQCP from categorical symmetry point of view,and strongly constrain the quantum field theory description of the QSL phase.The phase diagram and critical exponents presented in this paper are of direct relevance to future experiments on frustrated magnets and cold atom systems.
基金supported by National Natural Science Foundation of China(42201319)the Basic Research Project of Shenzhen Science and Technology Innovation Committee(JCYJ20180507182022554)+3 种基金the National Natural Science Foundation of China(71961137003,41890854,and 62102268)the Shenzhen Polytechnic Youth Innovation Project(6021310008K)the China Postdoctoral Science Foundation(2021M702231)the Basic and Applied Basic Research Funding Program of Guangdong Province of China(2019A1515110303).
文摘Asia stands out as a priority for urgent biodiversity conservation due to its large protected areas(PAs)and threatened species.Since the 21st century,both the highlands and lowlands of Asia have been experiencing the dramatic human expansion.However,the threat degree of human expansion to biodiversity is poorly understood.Here,the threat degree of human expansion to biodiversity over 2000 to 2020 in Asia at the continental(Asia),national(48 Asian countries),and hotspot(6,502 Asian terrestrial PAs established before 2000)scales is investigated by integrating multiple large-scale data.The results show that human expansion poses widespread threat to biodiversity in Asia,especially in Southeast Asia,with Malaysia,Cambodia,and Vietnam having the largest threat degrees(~1.5 to 1.7 times of the Asian average level).Human expansion in highlands induces higher threats to biodiversity than that in lowlands in one-third Asian countries(most Southeast Asian countries).The regions with threats to biodiversity are present in~75%terrestrial PAs(including 4,866 PAs in 26 countries),and human expansion in PAs triggers higher threat degrees to biodiversity than that in non-PAs.Our findings provide novel insight for the Sustainable Development Goal 15(SDG-15 Life on Land)and suggest that human expansion in Southeast Asian countries and PAs might hinder the realization of SDG-15.To reduce the threat degree,Asian developing countries should accelerate economic transformation,and the developed countries in the world should reduce the demands for commodity trade in Southeast Asian countries(i.e.,trade leading to the loss of wildlife habitats)to alleviate human expansion,especially in PAs and highlands.
基金supported by the Innovation Fund for Medical Sciences(CIFMS,2019-I2M-5-074,2021-I2M-1-026,2021-I2M-3-001)the Fundamental Research Funds for the Central Universities(lzujbky-2022-ey11,lzujbky-2022-40)the Funds for Fundamental Research Creative Groups of Gansu Province(20JR5RA310)。
文摘Chirality transformation is a basic,attractive,and important strategy for obtaining enantioenriched products with desired chiral elements.The reported chirality conversion reaction often involves the process from one type of chirality to another one.To better utilize the chirality transformation strategy for obtaining two or more products with different chiral elements in a single reaction,a new method of kinetic resolution accompanied by a chirality transformation protocol is proposed and successfully realized in this study.This process is used for the asymmetric oxidation of phenol compounds along with the kinetic resolution of oxaziridines.A wide scope of products,including axially chiral phenols,oxaziridines,andα-hydroxyl cyclic ketones were smoothly obtained in high levels of yields and enantioselectivities in the developed method.These products can be readily used for the synthesis of various types of chiral ligands,which are potential choices for other catalytic asymmetric reactions.
基金Project supported by the Natural Science Foundation of Jiangsu Province (Grant No.BK20220917)the National Natural Science Foundation of China (Grant Nos.12001213 and 12302035)。
文摘We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak noise.We aim to consider a next-to-leading-order approximation for more accurate calculation of the mean exit time by computing large deviation prefactors with the aid of machine learning.More specifically,we design a neural network framework to compute quasipotential,most probable paths and prefactors based on the orthogonal decomposition of a vector field.We corroborate the higher effectiveness and accuracy of our algorithm with two toy models.Numerical experiments demonstrate its powerful functionality in exploring the internal mechanism of rare events triggered by weak random fluctuations.
基金financially supported by the National Key Research and Development Program of China(No.2022YFA1503102)the National Natural Science Foundation of China(Nos.22022504,22003022,and 22203041)+3 种基金Guangdong Basic and Applied Basic Research Foundation,China(No.2021A1515110406)Guangdong“Pearl River”Talent Plan(No.2019QN01L353)Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)supported by the Center for Computational Science and Engineering at the Southern University of Science and Technology(SUSTech).
文摘The reduction degree of TiO_(2)support is critical to the performances of metal catalysts.In many previous theoretical calculations,only the bridge oxygen vacancy(Ov)was considered as the electron-donating defect on reduced rutile TiO_(2)(r-TiO_(2−x))supports.However,titanium adatoms(Tiad.),oxidized titanium islands(Tiad.On),and acid hydroxyls(ObrH)also exist at the metal/support interface.By conducting density functional theory(DFT)calculations and ab initio molecular dynamics(AIMD)simulations,we compared r-TiO_(2−x)surfaces with Ov,Tiad.,Tiad.On,and ObrH sites loaded with Au nanoparticles(NPs).The results showed the Au NPs were oxygen-phobic but titanium-philic,resulting in wetting of Ov and Tiad.but short contact with Tiad.On and ObrH.The Bader charges of Au NPs(QM)showed a good linear relationship with the ideal number of donating electrons(Ne)from the defective sites(QM=−KeNe+QM,S),demonstrating the intrinsic electron allocation at the interface.The Ov,Tiad.,and Tiad.On exhibited similar slopes(Ke),relatively steeper than that of ObrH.That means in the scope of Au NP charge state,the Tiad.and Tiad.On have a close electron-donating ability with Ov,but the ObrH donates relatively fewer electrons.This linear relationship can be extended approximately to other metals.The higher the metal work function,the steeper the Ke for easier electron donation from defective sites.The stronger the metal oxygen affinity,the more positive the intercept(QM,S).That explains the easy generation of metallic or negative Pt and Au NPs on r-TiO_(2−x),but hard for Cu and Zn in experiment.That provides theoretical guidance for regulating the charge of metal NPs over TiO_(2−x)supports.
基金Financial support from the National Natural Science Foundation of China (grant nos.22025103,92256301,21831002,22271133,22101122,and 22201127)the National Key R&D Program of China (grant nos.2021YFF0701604 and 2021YFF0701704)+1 种基金New Cornerstone Science Foundation through the XPLORER PRIZE,Shenzhen Science and Technology Program (grant nos.KQTD20210811090112004 and JCYJ20220818100600001)Shenzhen Key Laboratory of Cross-Coupling Reactions (grant no.ZDSYS20220328104200001).
文摘Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso compound feedstocks.Two strategic modes have been developed for these reactions,which differ in the nature of the stereo-determining steps.The first category deals primarily with the stereoselective desymmetrization of closed-shell radical precursors or functional reagents,whereas the second category achieves desymmetrization by stereoselectively functionalizing open-shell radical species.This mini-review explores the research progress in this growing field,aiming to elucidate mechanistic scenarios related to stereochemical control.Additionally,it offers insights into the challenges and opportunities that lie ahead for further development.
基金supported by the National Natural Science Foundation of China(Nos.21976034,42077193,92044301,and21906024)the Shanghai Municipal Health Commission Science and Research Fund(No.202040185)+1 种基金the Shanghai Pudong New District Bureau of Ecology and Environment Research Project(No.PDHJ20210008)the Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Great Bay Area(No.2021B1212050024)。
文摘The reaction of carbonyl-to-imine/hemiaminal conversion in the atmospheric aqueous phase is a critical pathway to produce the light-absorbing N-containing secondary organic compounds(SOC).The formation mechanism of these compounds has been wildly investigated in bulk solutions with a low ionic strength.However,the ionic strength in the aqueous phase of the polluted atmosphere may be higher.It is still unclear whether and to what extent the inorganic ions can affect the SOC formation.Here we prepared the bulk solution with certain ionic strength,in which glyoxal and ammonium were mixed to mimic the aqueous-phase reaction.Molecular characterization by High-resolution Mass Spectrometry was performed to identify the N-containing products,and the light absorption of the mixtures was measured by ultraviolet-visible spectroscopy.Thirty-nine N-containing compounds were identified and divided into four categories(N-heterocyclic chromophores,high-molecular-weight compounds with N-heterocycle,aliphatic imines/hemiaminals,and the unclassified).It was observed that the longer reaction time and higher ionic strength led to the formation of more N-heterocyclic chromophores and the increasing of the lightabsorbance of the mixture.The added inorganic ions were proposed to make the aqueous phase somewhat viscous so that the molecules were prone to undergo consecutive and intramolecular reactions to form the heterocycles.In general,this study revealed that the enhanced ionic strength and prolonged reaction time had the promotion effect on the lightabsorbing SOC formation.It implies that the aldehyde-derived aqueous-phase SOC would contribute more light-absorbing particulate matter in the industrial or populated area where inorganic ions are abundant.
基金supported by the National Key R&D Program of China(2018YFA0305900)the National Natural Science Foundation of China(52001339,52090020,and 52288102)the Natural Science Foundation of Hebei Province of China(E2022203109).
文摘The outstanding thermoelectric material, SnSe, is also known for its inferior mechanical properties, which bring great inconvenience for its application in thermoelectric devices. In this work, SnSe bulks were prepared via a sequential procedure of high-pressure synthesis (HPS), ball milling, and spark plasma sintering (SPS). The produced polycrystalline samples with a unique microstructure of tightly-bound quasi-equiaxed grains exhibited excellent mechanical properties. The Vickers hardness (HV), compressive strength (σ_(c)), and bending strength (σ_(b)) reached 1.1 GPa, 300 MPa, and 90 MPa, respectively, all of which are far superior to those of ordinary polycrystalline SnSe. Furthermore, the microstructures did not deteriorate thermoelectric performance. This work demonstrated an effective procedure to prepare polycrystalline microstructure-engineered SnSe materials, which not only show advantages in device applications but also shed light on property enhancement for other layer-structured thermoelectric materials.
基金supported by the National Natural Science Foundation of China(41876090,32101367,41976161)the Guangdong Basic and Applied Basic Research Foundation(2022A1515010698)+1 种基金the Science,Technology,and Innovation Commission of Shenzhen Municipality(JCYJ20220818095601003,JCYJ20170818092901989,20200827115203001)the Research Grants Council of the Hong Kong Special Administrative Region,China(UGC/IDS(R)16/19).
文摘Background Mangrove tannins can participate in wetland biogeochemical cycling.However,their fate and dynamics during leaf litter leaching have yet to be elucidated in coastal aquatic environments.Methods By using a simulated microcosm experiment,changes in leaf litter mass and tannin compounds,including total phenolics(TP),extractable condensed tannins(ECT),and bound condensed tannins(BCT),were examined in the litters and leachates of four common mangrove species:Kandelia obovata(Ko),Aegiceras corniculatum(Ac),Sonneratia apetala(Sa),and Avicennia marina(Am).Results Leaching caused a notable decline in litter mass,TP,and ECT in the leaf litter of Ko,Ac,Sa,and Am,while BCT increased significantly in Ko and Ac.Loss in foliar TP was higher than in leaf litter mass,and loss in foliar ECT was higher than in TP of Ko and Ac,but Sa showed the opposite result.The temporal changes of TP and ECT concentrations in leachates followed a similar trend,with an initial increase followed by a decrease.ECT dynamics in Ko and Ac leachates correlated with their TP concentrations,while in Sa leachate,the peak ECT occurred 72 h later than its TP peak.The leachate ECT concentrations were highest in Ac,followed by Ko,and significantly lower in Sa.The peak TP and ECT proportions in leachates accounted for 9.2-23.9%and 7.7-9.4%of the total decreases in foliar TP and ECT,respectively.Conclusion During the leaching process,tannins’fate was species-specific,while the dynamics were almost similar.
基金This project,as one of five key projects,is being carried out by using FAST,a Chinese national mega-science facility built and operated by the National Astronomical Observatories,Chinese Academy of Sciencessupported by the National Natural Science Foundation of China(NSFC,Nos.11988101 and 11833009)+5 种基金the Key Research Program of the Chinese Academy of Sciences(grant No.QYZDJ-SSWSLH021)supported by the Cultivation Project for the FAST scientific Payoff and Research Achievement of CAMS-CASsupported by NSFC No.12133004,partially supported by NSFC No.U1731120partially supported by the NSFC No.11873058,partially supported by NSFC No.U2031115partially supported by the National SKA program of China No.2020SKA0120200partially supported by the Guangzhou Science and Technology Project No.202102010466。
文摘We have carried out the Galactic Plane Pulsar Snapshot(GPPS)survey by using the Five-hundred-meter Aperture Spherical radio Telescope(FAST),the most sensitive systematic pulsar survey in the Galactic plane.In addition to more than 500 pulsars already discovered through normal periodical search,we report here the discovery of 76 new transient radio sources with sporadic strong pulses,detected by using the newly developed module for a sensitive single-pulse search.Their small DM values suggest that they all are Galactic rotating radio transients(RRATs).They show different properties in the follow-up observations.More radio pulses have been detected from 26 transient radio sources but no periods can be found due to a limited small number of pulses from all FAST observations.The followup observations show that 16 transient sources are newly identified as being the prototypes of RRATs with a period already determined from more detected sporadic pulses,and 10 sources are extremely nulling pulsars,and 24 sources are weak pulsars with sparse strong pulses.On the other hand,48 previously known RRATs have been detected by the FAST,either during verification observations for the GPPS survey or through targeted observations of applied normal FAST projects.Except for one RRAT with four pulses detected in a session of 5-minute observation and four RRATs with only one pulse detected in a session,sensitive FAST observations reveal that 43 RRATs are just generally weak pulsars with sporadic strong pulses or simply very nulling pulsars,so that the previously known RRATs always have an extreme emission state together with a normal hardly detectable weak emission state.This is echoed by the two normal pulsars J1938+2213 and J1946+1449 with occasional brightening pulses.Though strong pulses of RRATs are very outstanding in the energy distribution,their polarization angle variations follow the polarization angle curve of the averaged normal pulse profile,suggesting that the predominant sparse pulses of RRATs are emitted in the same re
基金financial support from National Natural Science Foundation of China[grant numbers 42171400,71961137003,82103945]Research on Prevention and Control of COVID-19 in Guangdong Education Department[grant number 2020KZDZX1171]+2 种基金Natural Science Foundation of Guangdong[grant number 2021A1515011324]Natural Resources of Guangdong[grant number 202325]Shenzhen Science and Technology Innovation Commission[grant number JCYJ20190808174209308].
文摘Mobility restriction measures were the main tools to control the spread of COVID-19,but the extent to which the mobility has decreased remained unsure.We investigated the change in local population mobility and its correlation with COVID-19 infections,using 1185 billion aggregated mobile phone data records in nine main cities in China from 10 January to 24 February 2020.The mobility fell by as much as 79.57%compared to the normal days in 2020 and by 58.13%compared to the same lunar period in 2019.The daily incidence of COVID-19 was significantly correlated with local daily mobility(R2=0.77,P<0.001).The instantaneous reproduction number R(t)declined by 3%when mobility was reduced by 10%in the GLM analysis(P<0.05).Our study indicated that the decreased mobility level,driven by a mixture effect of holiday and public health interventions,could substantially reduce the transmission of COVID-19 to a low level.Our study could provide evidence of mobility restriction to control local transmission for other places facing COVID-19 outbreaks or potential next waves.
基金supported by the National Natural Science Foundation of China(21906033)the introduced innovative R&D team project under the“The Pearl River Talent Recruitment Program”of Guangdong Province(2019ZT08L387)+2 种基金the Natural Science Foundation of Guangzhou City(202102020570,202201020392)the Depar tment of Science and Technology of Hubei Province(2019CFB365)the Department of Education of Hubei Province(Q20192805)
文摘Non-antibiotic fungicides are urgently needed due to the potential threat of drug-resistant bacteria to human health.In this research,a novel antibacterial nanoplatform based on CeO_(2)@C-N has been developed to achieve rapid near-infrared(NIR)laser-induced sterilization.The prepared CeO_(2)@C-N hybrid material exhibited a nanowire-like structure,with dispersed CeO_(2)nanoparticles averaging 5 nm in size within the heterogeneous configuration.X-ray photoelectron spectroscopy(XPS)and Raman spectra revealed that the heterogenous structures have a significant amount of oxygen vacancies and defects.Notably,CeO_(2)@C-N has a narrower band gap than CeO_(2),which allows for broader absorbance extending to the NIR region.With these unique physiochemical properties,CeO_(2)@C-N could inactivate E.coli and MRSA at a low concentration(20 mg/L)under 808 nm NIR laser(1 W/cm^(2))irradiation.The excellent bactericidal activity of CeO_(2)@C-N is attributed to the combination of photodynamic and photo thermal processes,based on its excellent photo-thermal conversion property,detection of reactive oxygen species(ROS)(^(1)O_(2)and·OH)under light irradiation,and scavenger quenching experiment results.This study offers a feasible and efficient way to fabricate a highly effective antibacterial candidate.
基金The Second Tibetan Plateau ScientificExpeditionand Research(STEP)program(2019QZKK0106)the National Natural Science Foundation of China(91837312)Postdoctoral Science Foundation of China(2019M660751).
基金supported by the National Natural Science Foundation of China(No.71872131)the STU Scientific Research Initiation Grant(No.20007)+1 种基金the Wenzhou Science and Technology Plan Project(No.G20220035)the General Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202248776)。
文摘With the rapid development of computer vision,point clouds technique was widely used in practical applications,such as obstacle detection,roadside detection,smart city construction,etc.However,how to efficiently identify the large scale point clouds is still an open challenge.For relieving the large computation consumption and low accuracy problem in point cloud classification,a large scale point cloud classification framework based on light bottle transformer(light-Bot Net)is proposed.Firstly,the two-dimensional(2D)and three-dimensional(3D)feature values of large scale point cloud were extracted for constructing point cloud feature images,which employed the prior knowledge to normalize the point cloud features.Then,the feature images are input to the classification network,and the light-Bot Net network is applied for point cloud classification.It is an interesting attempt to combine the traditional image features with the transformer network.For proving the performance of the proposed method,the large scale point cloud benchmark Oakland 3D is utilized.In the experiments,the proposed method achieved 98.1%accuracy on the Oakland 3D dataset.Compared with the other methods,it can both reduce the memory consumption and improve the classification accuracy in large scale point cloud classification.
基金supported by the National Natural Science Foundation of China(Nos.92050203,61925507,12174264,12004261,62075138,and 61827815)the Natural Science Foundation of Guangdong Province(Nos.2021A1515011909 and 2022A1515011457)the Shenzhen Fundamental Research Projects(Nos.JCYJ20200109105606426,JCYJ20190808164007485,JCYJ20190808121817100,JCYJ20190808143419622,and JCYJ20190808115601653).
文摘We report on a vortex laser chirped-pulse amplification(CPA)system that delivers pulses with a peak power of 45 TW.A focused intensity exceeding 1019 W/cm2 has been demonstrated for the first time by the vortex amplification scheme.Compared with other schemes of strong-field vortex generation with high energy flux but narrowband vortex-converting elements at the end of the laser,an important advantage of our scheme is that we can use a broadband but size-limited q-plate to realize broadband mode-converting in the front end of the CPA system,and achieve high-power amplification with a series of amplifiers.This method is low cost and can be easily implemented in an existing laser system.The results have verified the feasibility to obtain terawatt and even petawatt vortex laser amplification by a CPA system,which has important potential applications in strong-field laser physics,for example,generation of vortex particle beams with orbital angular momentum,fast ignition for inertial confinement fusion and simulation of the extreme astrophysical environment.
基金This work was supported by Guangdong Basic and Applied Basic Research Foundation(2019A1515010741 and 2021A1515110910)Guangdong Regional Joint Fund-Youth Fund(2020A1515111142)Shenzhen Science and Technology Program(JCYJ20210324093210029).
文摘Background:Mangrove forests are a significant contributor to the global carbon cycle,and the accurate estimation of their gross primary productivity(GPP)is essential for understanding the carbon budget within blue carbon ecosystems.Little attention has been given to the investigation of spatiotemporal patterns and ecological variations within mangrove ecosystems,as well as the quantitative analysis of the influence of geo-environmental factors on time-series estimations of mangrove GPP.Methods:This study explored the spatiotemporal dynamics of mangrove GPP from 2000 to 2020 in Gaoqiao Mangrove Reserve,China.A leaf area index(LAI)-based light-use efficiency(LUE)model was combined with Landsat data on Google Earth Engine(GEE)to reveal the variations in mangrove GPP using the Mann-Kendall(MK)test and Theil-Sen median trend.Moreover,the spatiotemporal patterns and ecological variations in mangrove ecosystems across regions were explored using four landscape indicators.Furthermore,the effects of six geo-environmental factors(species distribution,offshore distance,elevation,slope,planar curvature and profile curvature)on GPP were investigated using Geodetector and multi-scale geo-weighted regression(MGWR).Results:The results showed that the mangrove forest in the study area experienced an area loss from 766.26 ha in 2000 to 718.29 ha in 2020,mainly due to the conversion to farming,terrestrial forest and aquaculture zones.Landscape patterns indicated high levels of vegetation aggregation near water bodies and aquaculture zones,and low levels of aggregation but high species diversity and distribution density near building zone.The mean value of mangrove GPP continuously increased from 6.35 g C⋅m^(-2)⋅d^(-1) in 2000 to 8.33 g C⋅m^(-2)⋅d^(-1) in 2020,with 23.21%of areas showing a highly and significantly increasing trend(trend value>0.50).The Geodetector and MGWR analyses showed that species distribution,offshore distance and elevation contributed most to the GPP variations.Conclusions:These results provide guideli
基金financial support from the China National Social Science Foundation Key Research Project (Project No.17ZDA086)
文摘According to the risk management and reputation insurance theory of corporate social responsibility, corporate donations can help a company to repair its reputation after a crisis.This study uses a propensity score matching–difference in difference(PSM + DID) methodology to investigate the charitable donation activities of companies that have been subject to regulatory penalties.The analysis of a sample of A-share listed companies in the 2004–2016 period shows that companies significantly increase their charitable donations after regulatory penalties, but this effect weakens over time.Further analysis reveals that non-state-owned companies, companies with higher ownership concentrations, and companies receiving severer penalties are more motivated to make donations after regulatory penalties.By studying the reputation repair behavior of companies that have been subject to regulatory penalties, this study offers further support for the risk management and reputation insurance theory of corporate social responsibility.It also enriches our understanding of companies’ active responses to regulatory penalties and provides insights into companies’ motives for making charitable donations.
基金Songshan Lake Materials Laboratory 2022SLABFN06the National Natural Science Foundation of China(51902109)+3 种基金Basic Research Program of Guangzhou 202201010546Special Funds for the Cultivation of Guangdong college students’Scientific and Technological Innovation(‘Climbing Program’,pdjh2021b0136)National Nature Science Foundation of China(No.52003091)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515140155)for financial support.
文摘Organic electronics have gained significant attention in the field of biosensors owing to their immense potential for economical,lightweight,and adaptable sensing devices.This review explores the potential of organic electronics-based biosensors as a revolutionary technology for biosensing applications.The focus is on two types of organic biosensors:organic field effect transistor(OFET)and organic electrochemical transistor(OECT)biosensors.OFET biosensors have found extensive application in glucose,DNA,enzyme,ion,and gas sensing applications,but suffer from limitations related to low sensitivity and selectivity.On the other hand,OECT biosensors have shown superior performance in sensitivity,selectivity,and signal-to-noise ratio,owing to their unique mechanism of operation,which involves the modulation of electrolyte concentration to regulate the conductivity of the active layer.Recent advancements in OECT biosensors have demonstrated their potential for biomedical and environmental sensing,including the detection of neurotransmitters,bacteria,and heavy metals.Overall,the future directions of OFET and OECT biosensors involve overcoming these challenges and developing advanced devices with improved sensitivity,selectivity,reproducibility,and stability.The potential applications span diverse fields including human health,food analysis,and environment monitoring.Continued research and development in organic biosensors hold great promise for significant advancements in sensing technology,opening up new possibilities for biomedical and environmental applications.
基金financial support from the National Natural Science Foundation of China(Grant No.12303018)supported by the National Natural Science Foundation of China(Grant Nos.U2031201,11733001,and U2031112).+1 种基金the science research grants from the China Manned Space Project with(Grant No.CMSCSST-2021-A06)Scientific and Technological Cooperation Projects(20202023)between China and the Republic of Bulgaria。
文摘Relativistic outflows often exhibit extreme observational characteristics due to beaming effects, which makes measuring their jet power a challenging task. Although the spectral energy distribution(SED) obtained from multi-wavelength data can constrain the physical parameters of these jets, accurately estimating the Doppler factor remains difficult. To address this challenge, we assemble a comprehensive sample containing available SEDs of synchrotron and inverse Compton(IC) components, monochromatic luminosity, and broad-line region(BLR) emissions. We employ a parabolic equation to fit the synchrotron radiation SEDs,constraining jet physical parameters within the framework of a one-zone leptonic model. Our study delves into the jet properties and Doppler factor estimations, yielding the following key findings:(1) The fitting results of SED data for the entire sample reveal normal distributions of jet physical parameters for two subclasses of blazars.(2) Correlation analysis demonstrates that synchrotron peak luminosity exhibits a proportional relationship with both the radio and the γ-ray luminosities.(3) We introduce a novel method for estimating Doppler factors, which uncovers discrepancies between Doppler factors from this work and others from different techniques.
