Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on lo...Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).展开更多
Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,na...Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.展开更多
Twenty-nine species (24 genera, 6 families) of butterflies typical and common in northeast China were selected to make qualitative and quantitative studies on the pattern, hydrophobicity and hydrophobicity mechanism b...Twenty-nine species (24 genera, 6 families) of butterflies typical and common in northeast China were selected to make qualitative and quantitative studies on the pattern, hydrophobicity and hydrophobicity mechanism by means of scanning electron microscopy and contact angle measuring system. The scale surface is composed of submicro-class vertical gibbosities and horizontal links. The distance of scale is 48—91 μm, length 65—150 μm, and width 35—70 μm. The distance of submicro-class vertical gib-bosities on scale is 1.06—2.74 μm, height 200—900 nm, and width 200—840 nm. The better hydropho-bicity on the surface of butterfly wing (static contact angle 136.3°—156.6°) is contributed to the co-effects of micro-class scale and submicro-class vertical gibbosities on the wing surface. The Cassie equation was revised, and new mathematical models and equations were established.展开更多
The contact angles of distilled water and methanol solution on the wings of butterflies were determined by a visual contact angle measuring system. The scale structures of the wings were observed using scanning electr...The contact angles of distilled water and methanol solution on the wings of butterflies were determined by a visual contact angle measuring system. The scale structures of the wings were observed using scanning electron microscopy, The influence of the scale micro- and ultra-structure on the wettability was investigated. Results show that the contact angle of distilled water on the wing surfaces varies from 134.0° to 159.2°. High hydrophobicity is found in six species with contact angles greater than 150°. The wing surfaces of some species are not only hydrophobic but also resist the wetting by methanol solution with 55% concentration. Only two species in Parnassius can not resist the wetting because the micro-structure （spindle-like shape） and ultra-structure （pinnule-like shape） of the wing scales are remarkably different from that of other species. The concentration of methanol solution for the occurrence of spreading/wetting on the wing surfaces of different species varies from 70% to 95%. After wetting by methanol solution for 10 min, the distilled water contact angle on the wing surface increases by 0.8°-2.1°, showing the promotion of capacity against wetting by distilled water.展开更多
With the rapid development of economy and modern industry,serious environmental pollution and energy shortage have become major urgent challenges to the human society.Photocatalysis is a promising technology to provid...With the rapid development of economy and modern industry,serious environmental pollution and energy shortage have become major urgent challenges to the human society.Photocatalysis is a promising technology to provide green energy.As a typical metal-free polymer photocatalyst,g-C_(3)N_(4) has attracted more and more attention due to its excellent performance.Unfortunately,the fast recombination of photo-induced charges,limited light response range as well as weak oxidation ability are still the key drawback that restrict the photocatalytic performance of g-C_(3)N_(4).These problems can be effectively addressed by constructing g-C_(3)N_(4)-based heterojunctions with two or more semiconductor materials,during which the respective advantages can be integrated.Up to now,the various oxidation semiconductor photocatalysts have been tried to construct the novel S-scheme heterojunction photocatalysts with g-C_(3)N_(4).Thus,this review provides a comprehensive introduction of g-C_(3)N_(4)-based S-scheme heterojunctions,including the main characteristics of the S-scheme heterojunction,photocatalytic mechanisms,design rules and preparation methods of g-C_(3)N_(4)-based S-scheme heterojunction photocatalysts.Moreover,this review summarizes recently reported works on the potential applications of g-C_(3)N_(4)-based S-scheme photocatalysts in various important photocatalytic reactions,including photocatalytic hydrogen production,photocatalytic degradation of contaminants,photo-reduction of CO_(2) into fuels,and photocatalytic sterilization.Finally,based on the current research progress,we propose some shortages in the preparation methods and applications of g-C_(3)N_(4)-based S-scheme heterojunctions,which are to be further investigated and resolved in this promising and creative research field.展开更多
Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conv...Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conversion efficiency(PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)3 and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)3 solar cells and outline possible directions to further improve the device performance.展开更多
Humic substances(HS),which are defined as a series of highly acidic,relatively high-molecular-weight,and yellow to black colored substances formed during the decay and transformation of plant and microbial remains,ubi...Humic substances(HS),which are defined as a series of highly acidic,relatively high-molecular-weight,and yellow to black colored substances formed during the decay and transformation of plant and microbial remains,ubiquitously occur in nature.Humic substances represent the largest stable organic carbon pool in terrestrial environments and are the central characteristic of the soil.However,the validity of the HS concept and the justification of their extraction procedure have been recently debated.Here,we argue that the traditional humic paradigm is still relevant.Humic substances are distinctive and complex because the extracted HS formed during the humification are chemically distinct from their precursors and are heterogeneous among soils.By reviewing the concept,formation pathways,and stabilization of HS,we propose that the key question facing soil scientists is whether HS are soil microbial residues or unique synthesized compounds.Without revealing the distinctiveness of HS,it is impossible to address this question,as the structure,composition,and reactivity of HS are still poorly known owing to the heterogeneity and geographical variability of HS and the limits of the currently available analytical techniques.In our view,the distinctiveness of HS is fundamental to the soil,and thus further studies should be focused on revealing the distinctiveness of HS and explaining why HS hold this distinctiveness.展开更多
The number of lithium-ion batteries(LIBs)is steadily increasing in order to meet the ever-growing demand for sustainable energy and a high quality of life for humankind.At the same time,the resulting large number of L...The number of lithium-ion batteries(LIBs)is steadily increasing in order to meet the ever-growing demand for sustainable energy and a high quality of life for humankind.At the same time,the resulting large number of LIB waste certainly poses safety hazards if it is not properly disposed of and will seriously harm the environment due to its inherent toxicity due to the use of toxic substances.Moreover,the consumption of many scarce precious metal resources is behind the mass production of batteries.In the light of severe environmental,resources,safety and recycling problems,recycling spent LIBs have become an essential urgently needed action to achieve sustainable social development.This review therefore critically analyses the value and the need for recycling of spent LIBs from a variety of resources and the environment.A range of existing technologies for recycling and reusing spent LIBs,such as pretreatment,pyrometallurgy,hydrometallurgy,and direct recycled methods,is subsequently summarized exclusively.In addition,the benefits and problems of the methods described above are analyzed in detail.It also introduces recycling progress of other LIB components,such as anodes,separators,and electrolytes,as well as the high-value cathode.Finally,the prospects for recycling LIBs are addressed in four ways(government,users,battery manufacturers,and recyclers).This review should contribute to the development of the recycling of used LIBs,particularly in support of industrialization and recycling processes.展开更多
Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. H...Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. Herein, we report a nitrogen-doped porous carbon derived from biomass pomelo peel as sulfur host material for Li-S batteries. The hierarchical porous architecture and the polar surface introduced by N-doping render a favorable combination of physical and chemical sulfur confinements as well as an expedite electron/ion transfer, thus contributing to a facilitated and stabilized sulfur electrochemistry. As a result, the corresponding sulfur composite electrodes exhibit an ultrahigh initial capacity of 1534.6 mAh g^-1, high coulombic efficiency over 98% upon 300 cycles, and decent rate capability up to 2 C. This work provides an economical and effective strategy for the fabrication of advanced carbonaceous sulfur host material as well as the significant improvement of Li-S battery performance.展开更多
A metal-organic coordination polymer [Cd（tdc）（bimb）（μ2-H2O）]n （H2tdc = thiophe-ne-2,5-dicarboxylic acid, bimb = 1,4-bis（imidazol-l-yl）-butane） 1 has been hydrothermally synthe- sized and characterized by el...A metal-organic coordination polymer [Cd（tdc）（bimb）（μ2-H2O）]n （H2tdc = thiophe-ne-2,5-dicarboxylic acid, bimb = 1,4-bis（imidazol-l-yl）-butane） 1 has been hydrothermally synthe- sized and characterized by elemental analysis, IR, TG, luminescence spectrum and single-crystal X-ray diffraction. Colorless crystals crystallize in the triclinic system, space group P^-1 with a = 5.8945（3）, b = 10.3129（5）, c = 11.2226（5） A, a = 95.1430（10）,β = 97.9020（10）, γ = 90.5910（10）°, V = 672.84（6） A^3, C11H11CdN2O5S, Mr= 395.68, De = 1.953 g/cm^3, μ（MoKa） = 1.797 mm^-1, F（000） = 390, Z = 2, the final R = 0.0209 and wR = 0.0508 for 2514 observed reflections （I 〉 2σ（I））. The structure of 1 exhibits a two-dimensional layer-like structure.展开更多
As a cathode for sodium-ion batteries(SIBs),Na3V2(PO4)2F3(NVPF)with 3D open framework is a promising candidate due to its high working voltage and large theoretical capacity.However,the severe capacity degradation and...As a cathode for sodium-ion batteries(SIBs),Na3V2(PO4)2F3(NVPF)with 3D open framework is a promising candidate due to its high working voltage and large theoretical capacity.However,the severe capacity degradation and poor rate capability hinder its practical applications.The present study demonstrated the optimization of Na-storage performance of NVPF via delicate lattice modulation.Aliovalent substitution of V^(3^(+))at Na^(+)in NVPF induces the generation of electronic defects and expansion of Na^(+)-migration channels,resulting in the enhancement in electronic conductivity and acceleration of Na^(+)-migration kinetics.It is disclosed that the formed stronger Na O bonds with high ionicity than V O bonds lead to the significant increase in structural stability and ionicity in the Na^(+)-substituted NVPF(NVPF-Nax).The aforementioned effects of Na^(+)substitution achieve the unprecedented electrochemical performance in the optimized Na_(3.14)V1.93Na0.07(PO_(4))_(2)F_(3)(NVPF-Na_(0.07)).As a result,NVPF-Na0.07 delivers a high-rate capability(77.5 mAh g^(−1)at 20 C)and ultralong cycle life(only 0.027%capacity decay per cycle over 1000 cycles at 10 C).Sodium-ion full cells are designed using NVPF-Na0.07 as cathode and Se@reduced graphene oxide as anode.The full cells exhibit excellent wide-temperature electrochemical performance from−25 to 25C with an outstanding rate capability(96.3 mAh g^(−1)at 20 C).Furthermore,it delivered an excellent cycling performance over 300 cycles with a capacity retention exceeding 90%at 0.5 C under different temperatures.This study demonstrates a feasible strategy for the development of advanced cathode materials with excellent electrochemical properties to achieve high-efficiency energy storage.展开更多
MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect ...MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect on electrochemical performance. Herein, annealing MXene under hydrogen was employed for removing-F and turning-OH to-O terminations. We demonstrate that it improves the kinetics of Li-ion transport between the electrolyte and electrode. As a result, a lower interfacial charge transfer impedance was obtained. The electrochemical measurement exhibited that a nearly 2-fold increase of specific capacity was achieved for the annealed MXene.展开更多
The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of...The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.展开更多
An international cooperative study of the Late Cretaceous biota and non-marine strata including the Cretaceous-Paleogene(K--Pg) boundary in Jiayin near the Heilongjiang River,China during 2002-2010,is summarized in th...An international cooperative study of the Late Cretaceous biota and non-marine strata including the Cretaceous-Paleogene(K--Pg) boundary in Jiayin near the Heilongjiang River,China during 2002-2010,is summarized in this paper. The strata includes the Upper Cretaceous Yong'ancun-,Taipinglinchang-,Yuliang-zi-,and Furao formations,and the Paleocence Wuyun Formation consisting of Baoshantou Member and a Coalbearing Member. Seven palynological assemblages from Santonian to Paleocene are recognized,which is used for definition of the K--Pg boundary. Through the palynological analysis of three drilled boreholes (XHY-2005,2006,2008) in Xiaoheyan of western Jiayin,the K--Pg boundary is defined within 20. 00-20. 05 m in the borehole XHY-2006 (as a standard boundary) which is just between the top of Furao Formation (late Maasterichtian) and the base of Baishantou Member (early Danian) . These new research results are supported by paleo- magnetic,geochemical and other analyses,also. On the other hand,the presence of eight taxa of Maasterichtian dinosaurs (mostly hadrosaurids) have been recognized by the authors; and two mega-plant assemblages from the Yong'ancun Fm (Santonian) to Taipinglinchang Fm (Campanian) are confirmed. These research a-chievements indicate that the Upper Cretaceous-Paleocene in Jiayin can be well correlated to the strata in the neighboring Zeya-Bureja basin,Russia. The K--Pg boundary definited in Jiayin is the first well documented non-marine K--Pg boundary in China. Also the related paleoclimate,paleoenvironment and the mass extinctions in this area during the Cretaceous-Paleocene transition are also discussed.展开更多
The formation and growth of thermal fatigue crack in chromium wear resistant cast iron was investigated, and the effect of hot deformation on the crack was analyzed by means of optical microscope and scanning electron...The formation and growth of thermal fatigue crack in chromium wear resistant cast iron was investigated, and the effect of hot deformation on the crack was analyzed by means of optical microscope and scanning electron microscope and high frequency induction thermal fatigue tester. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, hot deformation can improve the eutectic carbiders morphology and distribution, inhibit the generation and propagation of thermal fatigue cracks. In the experiment, the propagation rate of thermal fatigue crack reduces with the quantity of hot deformation increasing, which was analyzed in the point view of the activation energy of crack propagation.展开更多
The Songliao Basin is one of the largest non-marine petroliferous basins in the globally and contains nearly complete Cretaceous terrestrial sedimentary records[1,2].The Shahezi Formation,named after Shahezi Village,C...The Songliao Basin is one of the largest non-marine petroliferous basins in the globally and contains nearly complete Cretaceous terrestrial sedimentary records[1,2].The Shahezi Formation,named after Shahezi Village,Changtu County,Liaoning Province,is a thick terrestrial clastic sedimentary succession deposited during the rift period of the Songliao Basin[1].Accordingly,it is significant for research on initial basin history restoration and global continental–marine stratigraphic correlation,to certificate the deposition time of the Shahezi Formation[2–4].展开更多
High-voltage high-nickel lithium layered oxide cathodes show great application prospects to meet the ever-increasing demand for further improvement of the energy density of rechargeable lithium-ion batteries(LIBs)main...High-voltage high-nickel lithium layered oxide cathodes show great application prospects to meet the ever-increasing demand for further improvement of the energy density of rechargeable lithium-ion batteries(LIBs)mainly due to their high output capacity.However,severe bulk structural degradation and undesired electrode-electrolyte interface reactions seriously endanger the cycle life and safety of the battery.Here,2 mol%Ti atom is used as modified material doping into LiNi_(0.8)Co_(0.2)Mn_(0.2O2)(NCM)to reform LiNi_(0.6)Co_(0.2)Mn_(0.18)Ti_(0.02)O_(2)(NCM-Ti)and address the long-standing inherent problem.At a high cut-off voltage of 4.5 V,NCM-Ti delivers a higher capacity retention ratio(91.8%vs.82.9%)after 150 cycles and a superior rate capacity(118 vs.105 mAh·g^(-1))at the high current density of 10 C than the pristine NCM.The designed high-voltage full battery with graphite as anode and NCM-Ti as cathode also exhibits high energy density(240 Wh·kg^(-1))and excellent electrochemical performance.The superior electrochemical behavior can be attributed to the improved stability of the bulk structure and the electrode-electrolyte interface owing to the strong Ti-O bond and no unpaired electrons.The in-situ X-ray diffraction analysis demonstrates that Ti-doping inhibits the undesired H2-H3 phase transition,minimizing the mechanical degradation.The ex-situ TEM and X-ray photoelectron spectroscopy reveal that Ti-doping suppresses the release of interfacial oxygen,reducing undesired interfacial reactions.This work provides a valuable strategic guideline for the application of high-voltage high-nickel cathodes in LIBs.展开更多
It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages o...It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages obtained from the marine deposits of Northeast Russia,Sakhalin,Kuril,and Hokkaido Islands,dated by ammonites,foraminifers and other invertebrates. Based on detail correlation,the geological age of the terrestrial beds was defined. The guide fossils are recognized Marsypiletes cretacea,Tricolpites variexi- nus,Aquilapollenites conatus,A. stelkii,A. rombicus,Integricorpus bellum,Pseudointegricorpus clarireticula- tus,Triprojectus amoenus,Orbiculapollis lucidus,Wodehouseia aspera,Quercoidites minor,which had last oc- currence in the late Maastrichtian. The Danian palynofloras usually are dominated by Triatriopollenites plicoides and T. confusus. The species Anacolosidites subtrudens,Aquilapollenites proceros,A. spinulosus have last occurrence in the Danian. The K-T (K-Pg) boundary in the terrestrial deposits is defined in the base of the Upper Tsagayan Subformation and the base of the lower part of the Wuyun Formation. The latter is represented by aleuropelite to fine-grained sandstones. The change of taxonomical composition of palynospectra in similar environments could be determined by real change of flora at the Mesozoic and Cenozoic boundary,but not by changes of lithological facies or depositional environment,generally.展开更多
Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Jap...Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.展开更多
The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads...The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.展开更多
基金partially supported by the National Key Research and Development Program of China(2016YFA0600104)supported by donations made by Delos Living LLC,and the Cyrus Tang Foundation+2 种基金supported by the National Natural Science Foundation of China(41471419)Beijing Institute of Urban Planningsupported by the Fundamental Research Funds for the Central Universities(CCNU19TD002).
文摘Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).
基金Supported in part by National Key Basic Research Program of China(2015CB856700)National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11822506,11835012,11935015,11935016,11935018,11961141012)+15 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility ProgramJoint Large-Scale Scientific Facility Funds of the NSFC and CAS(U 1732263,U 1832207)CAS Key Research Program of Frontier Sciences(QYZDJ-SSWSLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASINPAC and Shanghai Key Laboratory for Particle Physics and CosmologyERC(758462)German Research Foundation DFG under Contracts Nos.Collaborative Research Center CRC 1044,FOR 2359Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development o f Turkey(DPT2006K-120470)National Science and Technology fundOlle Engkvist Foundation(200-0605)STFC(United Kingdom)The Knut and Alice Wallenberg Foundation(Sweden)(2016.0157)The Royal Society,UK(DH140054,DH160214)The Swedish Research CouncilU.S.Department of Energy(DEFG02-05ER41374,DE-SC-0012069)。
文摘Using a dedicated data sample taken in 2018 on the J/ψpeak,we perform a detailed study of the trigger efficiencies of the BESIII detector.The efficiencies are determined from three representative physics processes,namely Bhabha scattering,dimuon production and generic hadronic events with charged particles.The combined efficiency of all active triggers approaches 100%in most cases,with uncertainties small enough not to affect most physics analyses.
基金Supported by Key Project of the National Natural Science Foundation of China (Grant No. 50635030)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20040183048)
文摘Twenty-nine species (24 genera, 6 families) of butterflies typical and common in northeast China were selected to make qualitative and quantitative studies on the pattern, hydrophobicity and hydrophobicity mechanism by means of scanning electron microscopy and contact angle measuring system. The scale surface is composed of submicro-class vertical gibbosities and horizontal links. The distance of scale is 48—91 μm, length 65—150 μm, and width 35—70 μm. The distance of submicro-class vertical gib-bosities on scale is 1.06—2.74 μm, height 200—900 nm, and width 200—840 nm. The better hydropho-bicity on the surface of butterfly wing (static contact angle 136.3°—156.6°) is contributed to the co-effects of micro-class scale and submicro-class vertical gibbosities on the wing surface. The Cassie equation was revised, and new mathematical models and equations were established.
文摘The contact angles of distilled water and methanol solution on the wings of butterflies were determined by a visual contact angle measuring system. The scale structures of the wings were observed using scanning electron microscopy, The influence of the scale micro- and ultra-structure on the wettability was investigated. Results show that the contact angle of distilled water on the wing surfaces varies from 134.0° to 159.2°. High hydrophobicity is found in six species with contact angles greater than 150°. The wing surfaces of some species are not only hydrophobic but also resist the wetting by methanol solution with 55% concentration. Only two species in Parnassius can not resist the wetting because the micro-structure （spindle-like shape） and ultra-structure （pinnule-like shape） of the wing scales are remarkably different from that of other species. The concentration of methanol solution for the occurrence of spreading/wetting on the wing surfaces of different species varies from 70% to 95%. After wetting by methanol solution for 10 min, the distilled water contact angle on the wing surface increases by 0.8°-2.1°, showing the promotion of capacity against wetting by distilled water.
基金supported by the National Natural Science Foundation of China(Nos.22008185,21872023)Shaanxi Provincial Key Research and Development Program(No.2022GY-166)。
文摘With the rapid development of economy and modern industry,serious environmental pollution and energy shortage have become major urgent challenges to the human society.Photocatalysis is a promising technology to provide green energy.As a typical metal-free polymer photocatalyst,g-C_(3)N_(4) has attracted more and more attention due to its excellent performance.Unfortunately,the fast recombination of photo-induced charges,limited light response range as well as weak oxidation ability are still the key drawback that restrict the photocatalytic performance of g-C_(3)N_(4).These problems can be effectively addressed by constructing g-C_(3)N_(4)-based heterojunctions with two or more semiconductor materials,during which the respective advantages can be integrated.Up to now,the various oxidation semiconductor photocatalysts have been tried to construct the novel S-scheme heterojunction photocatalysts with g-C_(3)N_(4).Thus,this review provides a comprehensive introduction of g-C_(3)N_(4)-based S-scheme heterojunctions,including the main characteristics of the S-scheme heterojunction,photocatalytic mechanisms,design rules and preparation methods of g-C_(3)N_(4)-based S-scheme heterojunction photocatalysts.Moreover,this review summarizes recently reported works on the potential applications of g-C_(3)N_(4)-based S-scheme photocatalysts in various important photocatalytic reactions,including photocatalytic hydrogen production,photocatalytic degradation of contaminants,photo-reduction of CO_(2) into fuels,and photocatalytic sterilization.Finally,based on the current research progress,we propose some shortages in the preparation methods and applications of g-C_(3)N_(4)-based S-scheme heterojunctions,which are to be further investigated and resolved in this promising and creative research field.
基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21572041 and 21772030)for the financial support
文摘Owing to its nice performance, low cost, and simple solution-processing, organic-inorganic hybrid perovskite solar cell(PSC) becomes a promising candidate for next-generation high-efficiency solar cells.The power conversion efficiency(PCE) has boosted from 3.8% to 25.2% over the past ten years. Despite the rapid progress in PCE, the device stability is a key issue that impedes the commercialization of PSCs. Recently, all-inorganic cesium lead halide perovskites have attracted much attention due to their better stability compared with their organic-inorganic counterpart. In this progress report, we summarize the properties of CsPb(IxBr1-x)3 and their applications in solar cells. The current challenges and corresponding solutions are discussed. Finally, we share our perspectives on CsPb(IxBr1-x)3 solar cells and outline possible directions to further improve the device performance.
基金supported by the National Natural Science Foundation of China(Nos.41571231 and 41201221)the National Key Research and Development Program of China(No.2016YFD0200304)+3 种基金the Scientific Instrument and Equipment Development Project of Chinese Academy Sciences(CAS)(No.YJKYYQ20170058)the Natural Science Foundation of Jiangsu Province,China(No.BK2012496)the Youth Innovation Promotion Association,CAS(No.2017362)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.19KJB180010)。
文摘Humic substances(HS),which are defined as a series of highly acidic,relatively high-molecular-weight,and yellow to black colored substances formed during the decay and transformation of plant and microbial remains,ubiquitously occur in nature.Humic substances represent the largest stable organic carbon pool in terrestrial environments and are the central characteristic of the soil.However,the validity of the HS concept and the justification of their extraction procedure have been recently debated.Here,we argue that the traditional humic paradigm is still relevant.Humic substances are distinctive and complex because the extracted HS formed during the humification are chemically distinct from their precursors and are heterogeneous among soils.By reviewing the concept,formation pathways,and stabilization of HS,we propose that the key question facing soil scientists is whether HS are soil microbial residues or unique synthesized compounds.Without revealing the distinctiveness of HS,it is impossible to address this question,as the structure,composition,and reactivity of HS are still poorly known owing to the heterogeneity and geographical variability of HS and the limits of the currently available analytical techniques.In our view,the distinctiveness of HS is fundamental to the soil,and thus further studies should be focused on revealing the distinctiveness of HS and explaining why HS hold this distinctiveness.
基金financially supported by the National Natural Science Foundation of China(No.52173246)the 111 Project(B13013).
文摘The number of lithium-ion batteries(LIBs)is steadily increasing in order to meet the ever-growing demand for sustainable energy and a high quality of life for humankind.At the same time,the resulting large number of LIB waste certainly poses safety hazards if it is not properly disposed of and will seriously harm the environment due to its inherent toxicity due to the use of toxic substances.Moreover,the consumption of many scarce precious metal resources is behind the mass production of batteries.In the light of severe environmental,resources,safety and recycling problems,recycling spent LIBs have become an essential urgently needed action to achieve sustainable social development.This review therefore critically analyses the value and the need for recycling of spent LIBs from a variety of resources and the environment.A range of existing technologies for recycling and reusing spent LIBs,such as pretreatment,pyrometallurgy,hydrometallurgy,and direct recycled methods,is subsequently summarized exclusively.In addition,the benefits and problems of the methods described above are analyzed in detail.It also introduces recycling progress of other LIB components,such as anodes,separators,and electrolytes,as well as the high-value cathode.Finally,the prospects for recycling LIBs are addressed in four ways(government,users,battery manufacturers,and recyclers).This review should contribute to the development of the recycling of used LIBs,particularly in support of industrialization and recycling processes.
基金financially supported by the Natural Science Foundation of Beijing (No. L182062)the Beijing Nova program (Z171100001117077)+5 种基金the Yue Qi Young Scholar Project of China University of Mining & Technology (Beijing) (No. 2017QN17)the Fundamental Research Funds for the Central Universities (No.2014QJ02)the program for the Development of Science and Technology of Jilin Province (Nos. 20190201309JC and 20190101009JH)the Project of Development and Reform Commission of Jilin Province (No. 2019C042-1)the support from Natural Sciences and Engineering Research Council of Canada (NSERC)the University of Waterloo.
文摘Lithium-sulfur(Li-S) battery is a potential energy storage technology with high energy density and low cost. However, the gap between theoretical expectation and practical performance limits its wide implementation. Herein, we report a nitrogen-doped porous carbon derived from biomass pomelo peel as sulfur host material for Li-S batteries. The hierarchical porous architecture and the polar surface introduced by N-doping render a favorable combination of physical and chemical sulfur confinements as well as an expedite electron/ion transfer, thus contributing to a facilitated and stabilized sulfur electrochemistry. As a result, the corresponding sulfur composite electrodes exhibit an ultrahigh initial capacity of 1534.6 mAh g^-1, high coulombic efficiency over 98% upon 300 cycles, and decent rate capability up to 2 C. This work provides an economical and effective strategy for the fabrication of advanced carbonaceous sulfur host material as well as the significant improvement of Li-S battery performance.
基金supported by the Science and Technology Research Projects of the Education Department of Jilin Province (No. 2012.479)
文摘A metal-organic coordination polymer [Cd（tdc）（bimb）（μ2-H2O）]n （H2tdc = thiophe-ne-2,5-dicarboxylic acid, bimb = 1,4-bis（imidazol-l-yl）-butane） 1 has been hydrothermally synthe- sized and characterized by elemental analysis, IR, TG, luminescence spectrum and single-crystal X-ray diffraction. Colorless crystals crystallize in the triclinic system, space group P^-1 with a = 5.8945（3）, b = 10.3129（5）, c = 11.2226（5） A, a = 95.1430（10）,β = 97.9020（10）, γ = 90.5910（10）°, V = 672.84（6） A^3, C11H11CdN2O5S, Mr= 395.68, De = 1.953 g/cm^3, μ（MoKa） = 1.797 mm^-1, F（000） = 390, Z = 2, the final R = 0.0209 and wR = 0.0508 for 2514 observed reflections （I 〉 2σ（I））. The structure of 1 exhibits a two-dimensional layer-like structure.
基金111 Project,Grant/Award Number:B13013Education Department of Jilin Province,Grant/Award Number:.JJKH20201179KJ+1 种基金Science Technology Program of Jilin Province,Grant/Award Number:20200201066JCNational Natural Science Foundation of China,Grant/Award Number:91963118。
文摘As a cathode for sodium-ion batteries(SIBs),Na3V2(PO4)2F3(NVPF)with 3D open framework is a promising candidate due to its high working voltage and large theoretical capacity.However,the severe capacity degradation and poor rate capability hinder its practical applications.The present study demonstrated the optimization of Na-storage performance of NVPF via delicate lattice modulation.Aliovalent substitution of V^(3^(+))at Na^(+)in NVPF induces the generation of electronic defects and expansion of Na^(+)-migration channels,resulting in the enhancement in electronic conductivity and acceleration of Na^(+)-migration kinetics.It is disclosed that the formed stronger Na O bonds with high ionicity than V O bonds lead to the significant increase in structural stability and ionicity in the Na^(+)-substituted NVPF(NVPF-Nax).The aforementioned effects of Na^(+)substitution achieve the unprecedented electrochemical performance in the optimized Na_(3.14)V1.93Na0.07(PO_(4))_(2)F_(3)(NVPF-Na_(0.07)).As a result,NVPF-Na0.07 delivers a high-rate capability(77.5 mAh g^(−1)at 20 C)and ultralong cycle life(only 0.027%capacity decay per cycle over 1000 cycles at 10 C).Sodium-ion full cells are designed using NVPF-Na0.07 as cathode and Se@reduced graphene oxide as anode.The full cells exhibit excellent wide-temperature electrochemical performance from−25 to 25C with an outstanding rate capability(96.3 mAh g^(−1)at 20 C).Furthermore,it delivered an excellent cycling performance over 300 cycles with a capacity retention exceeding 90%at 0.5 C under different temperatures.This study demonstrates a feasible strategy for the development of advanced cathode materials with excellent electrochemical properties to achieve high-efficiency energy storage.
基金financial support provided by the National Key R&D Program of China (2016YFA0200400)the Jilin Province/Jilin University co-Construction Project-Funds for New Materials (SXGJSF2017-3, Branch-2/440050316A36)+4 种基金the National Natural Science Foundation of China (Grant nos. 91545119, 21761132025, 21773269 and 51372095)the Youth Innovation Promotion Association CAS (Grant no. 2015152)Strategic Priority Research Program of the Chinese Academy of Sciences Chinese Academy of Sciences (Grant nos. XDA09030103 and XDA09040203)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT)"Double-First Class" Discipline for Materials Science & Engineering
文摘MXene has shown distinctive advantages as anode materials of lithium-ion batteries. However, local surface chemistry, which was confirmed that can block ion transfer and limit redox reaction, has a significant effect on electrochemical performance. Herein, annealing MXene under hydrogen was employed for removing-F and turning-OH to-O terminations. We demonstrate that it improves the kinetics of Li-ion transport between the electrolyte and electrode. As a result, a lower interfacial charge transfer impedance was obtained. The electrochemical measurement exhibited that a nearly 2-fold increase of specific capacity was achieved for the annealed MXene.
基金supported by the National Key R&D Program of China under Contract No.2022YFA1602200the International Partnership Program of the Chineses Academy of Sciences under Grant No.211134KYSB20200057the STCF Key Technology Research and Development Project.
文摘The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.
基金the Projects NSFC 30220130698 40842002Project"111"of China+2 种基金the Project of the Bureau of Land&Resources of Heilongjiang,China for their financial supports to this research workthe financial supports of Russian Projects RFFI No.04-04-49522the President Grantfor State Support of Leading Scientific Scholars in Russian Federation SS-1615 of Russia
文摘An international cooperative study of the Late Cretaceous biota and non-marine strata including the Cretaceous-Paleogene(K--Pg) boundary in Jiayin near the Heilongjiang River,China during 2002-2010,is summarized in this paper. The strata includes the Upper Cretaceous Yong'ancun-,Taipinglinchang-,Yuliang-zi-,and Furao formations,and the Paleocence Wuyun Formation consisting of Baoshantou Member and a Coalbearing Member. Seven palynological assemblages from Santonian to Paleocene are recognized,which is used for definition of the K--Pg boundary. Through the palynological analysis of three drilled boreholes (XHY-2005,2006,2008) in Xiaoheyan of western Jiayin,the K--Pg boundary is defined within 20. 00-20. 05 m in the borehole XHY-2006 (as a standard boundary) which is just between the top of Furao Formation (late Maasterichtian) and the base of Baishantou Member (early Danian) . These new research results are supported by paleo- magnetic,geochemical and other analyses,also. On the other hand,the presence of eight taxa of Maasterichtian dinosaurs (mostly hadrosaurids) have been recognized by the authors; and two mega-plant assemblages from the Yong'ancun Fm (Santonian) to Taipinglinchang Fm (Campanian) are confirmed. These research a-chievements indicate that the Upper Cretaceous-Paleocene in Jiayin can be well correlated to the strata in the neighboring Zeya-Bureja basin,Russia. The K--Pg boundary definited in Jiayin is the first well documented non-marine K--Pg boundary in China. Also the related paleoclimate,paleoenvironment and the mass extinctions in this area during the Cretaceous-Paleocene transition are also discussed.
基金ItemSponsored by Guiding Programof Science and Technology Research of Jilin Province of China (20000513)
文摘The formation and growth of thermal fatigue crack in chromium wear resistant cast iron was investigated, and the effect of hot deformation on the crack was analyzed by means of optical microscope and scanning electron microscope and high frequency induction thermal fatigue tester. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, hot deformation can improve the eutectic carbiders morphology and distribution, inhibit the generation and propagation of thermal fatigue cracks. In the experiment, the propagation rate of thermal fatigue crack reduces with the quantity of hot deformation increasing, which was analyzed in the point view of the activation energy of crack propagation.
基金This work was supported by the National Natural Science Foundation of China(41790453)the National Key Research&Development Program of China(2019YFC0605402)the China Geological Survey Program(DD20190010 and DD20160207)。
文摘The Songliao Basin is one of the largest non-marine petroliferous basins in the globally and contains nearly complete Cretaceous terrestrial sedimentary records[1,2].The Shahezi Formation,named after Shahezi Village,Changtu County,Liaoning Province,is a thick terrestrial clastic sedimentary succession deposited during the rift period of the Songliao Basin[1].Accordingly,it is significant for research on initial basin history restoration and global continental–marine stratigraphic correlation,to certificate the deposition time of the Shahezi Formation[2–4].
基金This work is financially supported by the National Key R&D Program of China(No.2017YFE0198100)the National Natural Science Foundation of China(Nos.21975250 and 52072145)+4 种基金the Beijing Natural Science Foundation(No.2214061)the Scientific and Technological Developing Project of Jilin Province,China(No.YDZJ202101ZYTS185)the Capital Construction Fund Projects within the Budget of Jilin Province,China(No.2021C037-2)the Open Project Program of Key Laboratory of Preparation and Application of Environmental Friendly Materials(Jilin Normal University),Ministry of Education,China(No.2020005)the Open Program of State Key Laboratory of Metastable Materials Science and Technology(Yanshan University),China(No.202110).
文摘High-voltage high-nickel lithium layered oxide cathodes show great application prospects to meet the ever-increasing demand for further improvement of the energy density of rechargeable lithium-ion batteries(LIBs)mainly due to their high output capacity.However,severe bulk structural degradation and undesired electrode-electrolyte interface reactions seriously endanger the cycle life and safety of the battery.Here,2 mol%Ti atom is used as modified material doping into LiNi_(0.8)Co_(0.2)Mn_(0.2O2)(NCM)to reform LiNi_(0.6)Co_(0.2)Mn_(0.18)Ti_(0.02)O_(2)(NCM-Ti)and address the long-standing inherent problem.At a high cut-off voltage of 4.5 V,NCM-Ti delivers a higher capacity retention ratio(91.8%vs.82.9%)after 150 cycles and a superior rate capacity(118 vs.105 mAh·g^(-1))at the high current density of 10 C than the pristine NCM.The designed high-voltage full battery with graphite as anode and NCM-Ti as cathode also exhibits high energy density(240 Wh·kg^(-1))and excellent electrochemical performance.The superior electrochemical behavior can be attributed to the improved stability of the bulk structure and the electrode-electrolyte interface owing to the strong Ti-O bond and no unpaired electrons.The in-situ X-ray diffraction analysis demonstrates that Ti-doping inhibits the undesired H2-H3 phase transition,minimizing the mechanical degradation.The ex-situ TEM and X-ray photoelectron spectroscopy reveal that Ti-doping suppresses the release of interfacial oxygen,reducing undesired interfacial reactions.This work provides a valuable strategic guideline for the application of high-voltage high-nickel cathodes in LIBs.
基金financial supports given by the NSFC(China,Projects 30220130698,40842002)the Presidium FEBRAS(grant#09-I-P15-02)
文摘It was conducted the comparison of palynological assemblages of the Middle Tsagayan,Upper Tsagayan subformations,Furao and Wuyun formations from Zeya-Bureya Basin of Amur (Heilongjiang) River region with assemblages obtained from the marine deposits of Northeast Russia,Sakhalin,Kuril,and Hokkaido Islands,dated by ammonites,foraminifers and other invertebrates. Based on detail correlation,the geological age of the terrestrial beds was defined. The guide fossils are recognized Marsypiletes cretacea,Tricolpites variexi- nus,Aquilapollenites conatus,A. stelkii,A. rombicus,Integricorpus bellum,Pseudointegricorpus clarireticula- tus,Triprojectus amoenus,Orbiculapollis lucidus,Wodehouseia aspera,Quercoidites minor,which had last oc- currence in the late Maastrichtian. The Danian palynofloras usually are dominated by Triatriopollenites plicoides and T. confusus. The species Anacolosidites subtrudens,Aquilapollenites proceros,A. spinulosus have last occurrence in the Danian. The K-T (K-Pg) boundary in the terrestrial deposits is defined in the base of the Upper Tsagayan Subformation and the base of the lower part of the Wuyun Formation. The latter is represented by aleuropelite to fine-grained sandstones. The change of taxonomical composition of palynospectra in similar environments could be determined by real change of flora at the Mesozoic and Cenozoic boundary,but not by changes of lithological facies or depositional environment,generally.
基金supported by the National Natural Science Foundation of China(31272331 and 31470458 to HW,31472013 and 31772453 to WL)the Fundamental Research Funds for the Central Universities(2412016KJ043)the Open Project Program of Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization(130028685)
文摘Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.
基金Project supported by the National Natural Science Foundation of China （Grant No 60372061）.
文摘The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.
