Field survey and greenhouse experiments were carried out to identify and characterize zinc (Zn) uptake and accumulation by a new Zn hyperaccumulating plant species (Sedum alfredii Hance) native to China. Zinc concentr...Field survey and greenhouse experiments were carried out to identify and characterize zinc (Zn) uptake and accumulation by a new Zn hyperaccumulating plant species (Sedum alfredii Hance) native to China. Zinc concentration in the shoots of Sedum alfredii Hance grown on an ancient mined area ranged from 4134 to 5000 mg/kg, with a mean of 4515 mg/kg. It suggests that Sedum alfredii could not only grow on heavily Pb/Zn contaminated soils, but also could accumulate extraordinarily high concentration of Zn. Under nutrient solution culture conditions, Sedum alfredii Hance grew healthy at Zn supplying levels from 0.006 to 240 mg · L-1. Zinc concentration in the shoots increased with external Zn levels increasing. The Zn concentration and accumulation in the shoots reached the highest at Zn supply level of SO mg/L, with 19.67 g/kg and 19.83 nig/plant, respectively. All the results showed that Sedum alfredii Hance is a new Zn hyperaccumulating plant. This provides a new plant material to explore mechanism of展开更多
The direct electron transfer of glucose oxidase (GOx) immobilized onto the surface of the carbon nanotube (CNT)-modified glassy carbon (CNT/GC) electrode is reported. The direct electron transfer rate of GOx is greatl...The direct electron transfer of glucose oxidase (GOx) immobilized onto the surface of the carbon nanotube (CNT)-modified glassy carbon (CNT/GC) electrode is reported. The direct electron transfer rate of GOx is greatly enhanced when it was immobilized onto the surface of CNT/GC electrode. Cyclic voltammetric results show a pair of well-defined and nearly symmetric redox peaks, which corresponds to the direct electron transfer of GOx, with the formal potential (E 0′), which is almost independent on the scan rates, of about ?0.456 V (vs. SCE) in the phosphate buffer solution (pH 6.9). The apparent heterogeneous electron transfer rate constant (ks) of GOx at the CNT/GC electrode surface is estimated to be (1.74 ± 0.42) s-1, which is much higher than that reported previously. The dependence of E 0′ on solution pH indicates that the direct electron transfer of GOx is a two-electron-transfer coupled with two-proton-transfer reaction process. The experimental results also demonstrate that the immobilized GOx retains its bioelectrocatalytic activity toward the oxidation of glucose. The method presented here can be easily extended to obtain the direct electrochemistry of other enzymes or proteins.展开更多
By combining vertical deposition with micro- molding in capillaries method, we have demonstrated the two-substrate vertical deposition, an alternative and versatile procedure for fabricating high-quality stable colloi...By combining vertical deposition with micro- molding in capillaries method, we have demonstrated the two-substrate vertical deposition, an alternative and versatile procedure for fabricating high-quality stable colloidal crystal chips. Apparent bright colors, special UV-vis spectra, scan- ning electron microscopy (SEM) and atomic force micros- copy (AFM) images all prove that high-quality colloidal crystal structures are formed in between the two substrates. During the two-substrate vertical deposition for colloidal crystal chips, capillary force and evaporation of the medium are critical to the formation of the colloidal crystals; while the confinement in between two close substrates makes the resulting colloidal crystal chips more stable. Due to the ex- cellent stability, these colloidal crystal chips can be used to construct some composite optical devices via a simpler and more flexible process. Meanwhile, they can also be further used as the templates for ordered multiporous materials.展开更多
Since the coal mine in-pit personnel positioning system neither can effectively achieve the function to detect the uniqueness of in-pit coal-mine personnel nor can identify and eliminate violations in attendance manag...Since the coal mine in-pit personnel positioning system neither can effectively achieve the function to detect the uniqueness of in-pit coal-mine personnel nor can identify and eliminate violations in attendance management such as multiple cards for one person, and swiping one's cards by others in China at present. Therefore, the research introduces a uniqueness detection system and method for in-pit coal-mine personnel integrated into the in-pit coal mine personnel positioning system, establishing a system mode based on face recognition + recognition of personnel positioning card + release by automatic detection. Aiming at the facts that the in-pit personnel are wearing helmets and faces are prone to be stained during the face recognition, the study proposes the ideas that pre-process face images using the 2D-wavelet-transformation-based Mallat algorithm and extracts three face features: miner light, eyes and mouths, using the generalized symmetry transformation-based algorithm. This research carried out test with 40 clean face images with no helmets and 40 lightly-stained face images, and then compared with results with the one using the face feature extraction method based on grey-scale transformation and edge detection. The results show that the method described in the paper can detect accurately face features in the above-mentioned two cases, and the accuracy to detect face features is 97.5% in the case of wearing helmets and lightly-stained faces.展开更多
Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,m...Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.展开更多
Optical metasurfaces are endowed with unparallel flexibility to manipulate the light field with a subwavelength spatial resolution.Coupling metasurfaces to materials with strong optical nonlinearity may allow ultrafas...Optical metasurfaces are endowed with unparallel flexibility to manipulate the light field with a subwavelength spatial resolution.Coupling metasurfaces to materials with strong optical nonlinearity may allow ultrafast spatiotemporal light field modulation.However,most metasurfaces demonstrated thus far are linear devices.Here,we experimentally demonstrate simultaneous spatiotemporal laser mode control using a single-layer plasmonic metasurface strongly coupled to an epsilon-near-zero(ENZ)material within a fiber laser cavity.While the geometric phase of the metasurface is utilized to convert the laser’s transverse mode from a Gaussian beam to a vortex beam carrying orbital angular momentum,the giant nonlinear saturable absorption of the ENZ material enables pulsed laser generation via the Q-switching process.The direct integration of a spatiotemporal metasurface in a laser cavity may pave the way for the development of miniaturized laser sources with tailored spatial and temporal profiles,which can be useful for numerous applications,such as superresolution imaging,high-density optical storage,and three-dimensional laser lithography.展开更多
In order to realize the accurate obstacle avoidance function of intelligent car, we propose an intelligent car obstacle avoidance system based on optimized fuzzy control algorithm. Firstly, the kinematics model of int...In order to realize the accurate obstacle avoidance function of intelligent car, we propose an intelligent car obstacle avoidance system based on optimized fuzzy control algorithm. Firstly, the kinematics model of intelligent car obstacle avoidance is established, and an efficient environment information collection system composed of multiple sensors is designed to realize the comprehensive collection of obstacle information. Then, the optimized fuzzy control system is adopted to improve the position control accuracy and obstacle avoidance ability. Through the physical debugging and joint simulation of the intelligent car fuzzy controller in the MATLAB and Simulink environment, the simulation results show that the control method can make the collision-free path planned by the intelligent car from the initial state to the obstacle avoidance smoother, and at the same time, the obstacle avoidance of the intelligent car. The actual running distance is reduced by about 16%, which can ensure the practicability of the obstacle avoidance system, provide a new guarantee for the safe operation of the car, and also provide a new idea for the development of the unmanned car.展开更多
Three-dimensional(3D)bioprinting,specifically direct ink writing(DIW)capable of printing biologically active substances such as growth factors or drugs under low-temperature conditions,is an emerging di-rection in bon...Three-dimensional(3D)bioprinting,specifically direct ink writing(DIW)capable of printing biologically active substances such as growth factors or drugs under low-temperature conditions,is an emerging di-rection in bone tissue engineering.However,limited by the bio-ink mobility and the poor resolution of this printing technology,the lateral pores of current crisscross-stacked scaffolds printed through DIW tend to clog and are inimical to bone growth.Therefore,it is critical to develop DIW printed biologi-cal scaffold structure with high mechanical strength,porosity,and biocompatibility performance.Herein,patterned polylactic acid(PLA)/polycaprolactone(PCL)/nano-hydroxyapatite(n-HA)based scaffold was printed through DIW technological and rolled-up for properties characterization,cytocompatibility test,and bone repair experiment.The result not only shows that the hexagonal patterned scaffolds are me-chanically strong with porosity,but also demonstrated that the hierarchical pore structure formed during rolled-up has the potential to address the clogging problem and stimulates bone growth and repair.展开更多
The globus pallidus plays a pivotal role in the basal ganglia circuit. Parkinson's disease is characterized by degeneration of dopamine-producing cells in the substantia nigra, which leads to dopamine deficiency i...The globus pallidus plays a pivotal role in the basal ganglia circuit. Parkinson's disease is characterized by degeneration of dopamine-producing cells in the substantia nigra, which leads to dopamine deficiency in the brain that subsequently manifests as various motor and non-motor symptoms. This review aims to summarize the involvement of the globus pallidus in both motor and non-motor manifestations of Parkinson's disease. The firing activities of parvalbumin neurons in the medial globus pallidus, including both the firing rate and pattern, exhibit strong correlations with the bradykinesia and rigidity associated with Parkinson's disease. Increased beta oscillations, which are highly correlated with bradykinesia and rigidity, are regulated by the lateral globus pallidus. Furthermore,bradykinesia and rigidity are strongly linked to the loss of dopaminergic projections within the cortical-basal ganglia-thalamocortical loop. Resting tremors are attributed to the transmission of pathological signals from the basal ganglia through the motor cortex to the cerebellum-ventral intermediate nucleus circuit. The cortico–striato–pallidal loop is responsible for mediating pallidi-associated sleep disorders. Medication and deep brain stimulation are the primary therapeutic strategies addressing the globus pallidus in Parkinson's disease. Medication is the primary treatment for motor symptoms in the early stages of Parkinson's disease, while deep brain stimulation has been clinically proven to be effective in alleviating symptoms in patients with advanced Parkinson's disease,particularly for the movement disorders caused by levodopa. Deep brain stimulation targeting the globus pallidus internus can improve motor function in patients with tremordominant and non-tremor-dominant Parkinson's disease, while deep brain stimulation targeting the globus pallidus externus can alter the temporal pattern of neural activity throughout the basal ganglia–thalamus network. Therefore, the composition of the globus pallidus neurons, th展开更多
On-demand food delivery(OFD)is gaining more and more popularity in modern society.As a kernel order assignment manner in OFD scenario,order recommendation directly influences the delivery efficiency of the platform an...On-demand food delivery(OFD)is gaining more and more popularity in modern society.As a kernel order assignment manner in OFD scenario,order recommendation directly influences the delivery efficiency of the platform and the delivery experience of riders.This paper addresses the dynamism of the order recommendation problem and proposes a reinforcement learning solution method.An actor-critic network based on long short term memory(LSTM)unit is designed to deal with the order-grabbing conflict between different riders.Besides,three rider sequencing rules are accordingly proposed to match different time steps of the LSTM unit with different riders.To test the performance of the proposed method,extensive experiments are conducted based on real data from Meituan delivery platform.The results demonstrate that the proposed reinforcement learning based order recommendation method can significantly increase the number of grabbed orders and reduce the number of order-grabbing conflicts,resulting in better delivery efficiency and experience for the platform and riders.展开更多
Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of ...Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of bulky organic cation spacers limits the performance of 2DRP PSCs.Inspired by the Asite cation alloying strategy in 3D perovskites,2DRP perovskites with a binary spacer can promote charge transporting compared to the unary spacer counterparts.Herein,the superior MA-based 2DRP perovskite films with a binary spacer,including 3-guanidinopropanoic acid(GPA)and 4-fluorophenethylamine(FPEA)are realized.These films(GPA_(0.85)FPEA_(0.15))_(2)MA_(4)Pb_5I_(16)show good morphology,large grain size,decreased trap state density,and preferential orientation of the as-prepared film.Accordingly,the present 2DRP-based PSC with the binary spacer achieves a remarkable efficiency of 18.37%with a V_(OC)of1.15 V,a J_(SC)of 20.13 mA cm^(-2),and an FF of 79.23%.To our knowledge,the PCE value should be the highest for binary spacer MA-based 2DRP(n≤5)PSCs to date.Importantly,owing to the hydrophobic fluorine group of FPEA and the enhanced interlayer interaction by FPEA,the unencapsulated 2DRP PSCs based on binary spacers exhibit much excellent humidity stability and thermal stability than the unary spacer counterparts.展开更多
With current success of large-scale pre-trained models(PTMs),how efficiently adapting PTMs to downstream tasks has attracted tremendous attention,especially for PTMs with billions of parameters.Previous work focuses o...With current success of large-scale pre-trained models(PTMs),how efficiently adapting PTMs to downstream tasks has attracted tremendous attention,especially for PTMs with billions of parameters.Previous work focuses on designing parameter-efficient tuning paradigms but needs to save and compute the gradient of the whole computational graph.In this paper,we propose y-Tuning,an efficient yet effective paradigm to adapt frozen large-scale PTMs to specific downstream tasks.y-Tuning learns dense representations for labels y defined in a given task and aligns them to fixed feature representation.Without computing the gradients of text encoder at training phrase,y-Tuning is not only parameterefficient but also training-efficient.Experimental results show that for DeBERTaxxL with 1.6 billion parameters,y-Tuning achieves performance more than 96%of full fine-tuning on GLUE Benchmark with only 2%tunable parameters and much fewer training costs.展开更多
Metabolic reprogramming is a hallmark of cancer,including lung cancer.However,the exact underlying mechanism and therapeutic potential are largely unknown.Here we report that protein arginine methyltransferase 6(PRMT6...Metabolic reprogramming is a hallmark of cancer,including lung cancer.However,the exact underlying mechanism and therapeutic potential are largely unknown.Here we report that protein arginine methyltransferase 6(PRMT6)is highly expressed in lung cancer and is required for cell metabolism,tumorigenicity,and cisplatin response of lung cancer.PRMT6 regulated the oxidative pentose phosphate pathway(PPP)flux and glycolysis pathway in human lung cancer by increasing the activity of 6-phosphogluconate dehydrogenase(6PGD)and a-enolase(ENO1).Furthermore,PRMT6 methylated R324 of 6PGD to enhancing its activity;while methylation at R9 and R372 of ENO1 promotes formation of active ENO1 dimers and 2-phosphoglycerate(2-PG)binding to ENO1,respectively.Lastly,targeting PRMT6 blocked the oxidative PPP flux,glycolysis pathway,and tumor growth,as well as enhanced the antitumor effects of cisplatin in lung cancer.Together,this study demonstrates that PRMT6 acts as a posttranslational modification(PTM)regulator of glucose metabolism,which leads to the pathogenesis of lung cancer.It was proven that the PRMT6-6PGD/ENO1 regulatory axis is an important determinant of carcinogenesis and may become a promising cancer therapeutic strategy.展开更多
Multimode fiber(MMF)lasers are emerging as a remarkable testbed to study nonlinear spatiotemporal physics with potential applications spanning from high energy pulse generation,precision measurement to nonlinear micro...Multimode fiber(MMF)lasers are emerging as a remarkable testbed to study nonlinear spatiotemporal physics with potential applications spanning from high energy pulse generation,precision measurement to nonlinear microscopy.The underlying mechanism for the generation of ultrashort pulses,which can be understood as a spatiotempoal dissipative soliton(STDS),in the nonlinear multimode resonators is the spatiotemporal mode-locking(STML)with simultaneous synchronization of temporal and spatial modes.In this review,we first introduce the general principles of STML,with an emphasize on the STML dynamics with large intermode dispersion.Then,we present the recent progress of STML,including measurement techniques for STML,exotic nonlinear dynamics of STDS,and mode field engineering in MMF lasers.We conclude by outlining some perspectives that may advance STML in the near future.展开更多
Interconnectivity is the key characteristic of bone tissue engineering scaffold modulating cell migration,blood vessels invasion and transport of nutrient and waste.However,efforts and understanding of the interconnec...Interconnectivity is the key characteristic of bone tissue engineering scaffold modulating cell migration,blood vessels invasion and transport of nutrient and waste.However,efforts and understanding of the interconnectivity of porous Mg is limited due to the diverse architectures of pore struts and pore size distribution of Mg scaffold systems.In this work,biomimetic hierarchical porous Mg scaffolds with tailored interconnectivity as well as pore size distribution were prepared by template replication of infiltration casting.Mg scaffold with better interconnectivity showed lower mechanical strength.Enlarging interconnected pores would enhance the interconnectivity of the whole scaffold and reduce the change of ion concentration,pH value and osmolality of the degradation microenvironment due to the lower specific surface area.Nevertheless,the degradation rates of five tested Mg scaffolds were no different because of the same geometry of strut unit.Direct cell culture and evaluation of cell density at both sides of four typical Mg scaffolds indicated that cell migration through hierarchical porous Mg scaffolds could be enhanced by not only bigger interconnected pore size but also larger main pore size.In summary,design of interconnectivity in terms of pore size distribution could regulate mechanical strength,microenvironment in cell culture condition and cell migration potential,and beyond that it shows great potential for personalized therapy which could facilitate the regeneration process.展开更多
In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a ne...In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a neural fate. Previous studies have shown that the neural conversion of mouse ES cells includes both the participation of neural-specific transcription factors and the regulation of epigenetic modifications. However, the intracellular mechanism underlying this intrinsic transition still re- mains to be further elucidated. Herein, we describe a long intergenic non-coding RNA, LincRNA1230, which participates in the regulation of the neural lineage specification of mouse ES cells. The ectopic forced expression of LincRNAI230 dramatically inhibited mouse ES cells from adopting a neural cell fate, while LincRNA1230 knockdown promoted the conversion of mouse ES cells towards neural progenitors. Mechanistic studies have shown that LincRNA1230 inhibits the activation of early neural genes, such as Pax6 and Soxl, through the modulation of bivalent modifications （tri-methylation of histone3 lysine4 and his- tone3 lysine27） at the promoters of these genes. The interaction of LincRNA1230 with Wdr5 blocked the localization of Wdr5 at the promoters of early neural genes, thereby inhibiting the enrichment of H3K4me3 modifications at these loci. Collectively, these findings revealed a crucial role for LincRNA1230 in the regulation of the neural differentiation of mouse ES cells.展开更多
基金This work was supported by the Outstanding Young Scientist Program of the National Natural Science Foundation of China (Grant No. 39925024).
文摘Field survey and greenhouse experiments were carried out to identify and characterize zinc (Zn) uptake and accumulation by a new Zn hyperaccumulating plant species (Sedum alfredii Hance) native to China. Zinc concentration in the shoots of Sedum alfredii Hance grown on an ancient mined area ranged from 4134 to 5000 mg/kg, with a mean of 4515 mg/kg. It suggests that Sedum alfredii could not only grow on heavily Pb/Zn contaminated soils, but also could accumulate extraordinarily high concentration of Zn. Under nutrient solution culture conditions, Sedum alfredii Hance grew healthy at Zn supplying levels from 0.006 to 240 mg · L-1. Zinc concentration in the shoots increased with external Zn levels increasing. The Zn concentration and accumulation in the shoots reached the highest at Zn supply level of SO mg/L, with 19.67 g/kg and 19.83 nig/plant, respectively. All the results showed that Sedum alfredii Hance is a new Zn hyperaccumulating plant. This provides a new plant material to explore mechanism of
基金This work was supported by the National Natural Science Foundation of China(Grant No.20373027)the Foundation for Scientists Returned from Abroad directed under the Ministry of Education of China+1 种基金the Natural Science Foundation of Education Committee of Jiangsu Province(Grant No.03KJA150055)the Excellent Talent Project of Personnel Department of Nanjing City of Jiangsu Province.
文摘The direct electron transfer of glucose oxidase (GOx) immobilized onto the surface of the carbon nanotube (CNT)-modified glassy carbon (CNT/GC) electrode is reported. The direct electron transfer rate of GOx is greatly enhanced when it was immobilized onto the surface of CNT/GC electrode. Cyclic voltammetric results show a pair of well-defined and nearly symmetric redox peaks, which corresponds to the direct electron transfer of GOx, with the formal potential (E 0′), which is almost independent on the scan rates, of about ?0.456 V (vs. SCE) in the phosphate buffer solution (pH 6.9). The apparent heterogeneous electron transfer rate constant (ks) of GOx at the CNT/GC electrode surface is estimated to be (1.74 ± 0.42) s-1, which is much higher than that reported previously. The dependence of E 0′ on solution pH indicates that the direct electron transfer of GOx is a two-electron-transfer coupled with two-proton-transfer reaction process. The experimental results also demonstrate that the immobilized GOx retains its bioelectrocatalytic activity toward the oxidation of glucose. The method presented here can be easily extended to obtain the direct electrochemistry of other enzymes or proteins.
基金supported by the National Natural Science Foundation of China(Grant Nos.90401020 and 200340062).
文摘By combining vertical deposition with micro- molding in capillaries method, we have demonstrated the two-substrate vertical deposition, an alternative and versatile procedure for fabricating high-quality stable colloidal crystal chips. Apparent bright colors, special UV-vis spectra, scan- ning electron microscopy (SEM) and atomic force micros- copy (AFM) images all prove that high-quality colloidal crystal structures are formed in between the two substrates. During the two-substrate vertical deposition for colloidal crystal chips, capillary force and evaporation of the medium are critical to the formation of the colloidal crystals; while the confinement in between two close substrates makes the resulting colloidal crystal chips more stable. Due to the ex- cellent stability, these colloidal crystal chips can be used to construct some composite optical devices via a simpler and more flexible process. Meanwhile, they can also be further used as the templates for ordered multiporous materials.
基金financial supports from the National Natural Science Foundation of China (No. 51134024)the National High Technology Research and Development Program of China (No. 2012AA062203)are gratefully acknowledged
文摘Since the coal mine in-pit personnel positioning system neither can effectively achieve the function to detect the uniqueness of in-pit coal-mine personnel nor can identify and eliminate violations in attendance management such as multiple cards for one person, and swiping one's cards by others in China at present. Therefore, the research introduces a uniqueness detection system and method for in-pit coal-mine personnel integrated into the in-pit coal mine personnel positioning system, establishing a system mode based on face recognition + recognition of personnel positioning card + release by automatic detection. Aiming at the facts that the in-pit personnel are wearing helmets and faces are prone to be stained during the face recognition, the study proposes the ideas that pre-process face images using the 2D-wavelet-transformation-based Mallat algorithm and extracts three face features: miner light, eyes and mouths, using the generalized symmetry transformation-based algorithm. This research carried out test with 40 clean face images with no helmets and 40 lightly-stained face images, and then compared with results with the one using the face feature extraction method based on grey-scale transformation and edge detection. The results show that the method described in the paper can detect accurately face features in the above-mentioned two cases, and the accuracy to detect face features is 97.5% in the case of wearing helmets and lightly-stained faces.
基金financially supported by the Natural Science Foundation of China(Grants 51972172,61705102,and 51802253)the China Postdoctoral Science Foundation(Grants 2021M692630)+6 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2022JQ-629,2021JLM-43)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007 and 2020GXLH-Z-014)Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)the Innovation Project of Optics Valley Laboratory(OVL2021BG006)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF003)the Young 1000 Talents Global Recruitment Program of Chinathe Fundamental Research Funds for the Central Universities.
文摘Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.
基金the National Natural Science Foundation of China(62135008,61975251)by the Guoqiang Institute,Tsinghua University.
文摘Optical metasurfaces are endowed with unparallel flexibility to manipulate the light field with a subwavelength spatial resolution.Coupling metasurfaces to materials with strong optical nonlinearity may allow ultrafast spatiotemporal light field modulation.However,most metasurfaces demonstrated thus far are linear devices.Here,we experimentally demonstrate simultaneous spatiotemporal laser mode control using a single-layer plasmonic metasurface strongly coupled to an epsilon-near-zero(ENZ)material within a fiber laser cavity.While the geometric phase of the metasurface is utilized to convert the laser’s transverse mode from a Gaussian beam to a vortex beam carrying orbital angular momentum,the giant nonlinear saturable absorption of the ENZ material enables pulsed laser generation via the Q-switching process.The direct integration of a spatiotemporal metasurface in a laser cavity may pave the way for the development of miniaturized laser sources with tailored spatial and temporal profiles,which can be useful for numerous applications,such as superresolution imaging,high-density optical storage,and three-dimensional laser lithography.
文摘In order to realize the accurate obstacle avoidance function of intelligent car, we propose an intelligent car obstacle avoidance system based on optimized fuzzy control algorithm. Firstly, the kinematics model of intelligent car obstacle avoidance is established, and an efficient environment information collection system composed of multiple sensors is designed to realize the comprehensive collection of obstacle information. Then, the optimized fuzzy control system is adopted to improve the position control accuracy and obstacle avoidance ability. Through the physical debugging and joint simulation of the intelligent car fuzzy controller in the MATLAB and Simulink environment, the simulation results show that the control method can make the collision-free path planned by the intelligent car from the initial state to the obstacle avoidance smoother, and at the same time, the obstacle avoidance of the intelligent car. The actual running distance is reduced by about 16%, which can ensure the practicability of the obstacle avoidance system, provide a new guarantee for the safe operation of the car, and also provide a new idea for the development of the unmanned car.
基金supported by the China NSFC project(No.32171338)the Key Science and Technology Special Project of Sichuan Province(No.2020ZDZX0008)the Innovation and Reform Project of Postgraduate Education of Sichuan University in 2021,and the Experimental Technology Research Project of Sichuan University(No.SCU221099).
文摘Three-dimensional(3D)bioprinting,specifically direct ink writing(DIW)capable of printing biologically active substances such as growth factors or drugs under low-temperature conditions,is an emerging di-rection in bone tissue engineering.However,limited by the bio-ink mobility and the poor resolution of this printing technology,the lateral pores of current crisscross-stacked scaffolds printed through DIW tend to clog and are inimical to bone growth.Therefore,it is critical to develop DIW printed biologi-cal scaffold structure with high mechanical strength,porosity,and biocompatibility performance.Herein,patterned polylactic acid(PLA)/polycaprolactone(PCL)/nano-hydroxyapatite(n-HA)based scaffold was printed through DIW technological and rolled-up for properties characterization,cytocompatibility test,and bone repair experiment.The result not only shows that the hexagonal patterned scaffolds are me-chanically strong with porosity,but also demonstrated that the hierarchical pore structure formed during rolled-up has the potential to address the clogging problem and stimulates bone growth and repair.
基金supported by the National Natural Science Foundation of China,No.31771143 (to QZ)Shanghai Municipal Science and Technology Major Project,ZJ Lab+1 种基金Shanghai Center for Brain Science and Brain-Inspired Technology,No.2018SHZDZX01 (to LC)Shanghai Zhou Liangfu Medical Development Foundation “Brain Science and Brain Diseases Youth Innovation Program”(to ZQ)。
文摘The globus pallidus plays a pivotal role in the basal ganglia circuit. Parkinson's disease is characterized by degeneration of dopamine-producing cells in the substantia nigra, which leads to dopamine deficiency in the brain that subsequently manifests as various motor and non-motor symptoms. This review aims to summarize the involvement of the globus pallidus in both motor and non-motor manifestations of Parkinson's disease. The firing activities of parvalbumin neurons in the medial globus pallidus, including both the firing rate and pattern, exhibit strong correlations with the bradykinesia and rigidity associated with Parkinson's disease. Increased beta oscillations, which are highly correlated with bradykinesia and rigidity, are regulated by the lateral globus pallidus. Furthermore,bradykinesia and rigidity are strongly linked to the loss of dopaminergic projections within the cortical-basal ganglia-thalamocortical loop. Resting tremors are attributed to the transmission of pathological signals from the basal ganglia through the motor cortex to the cerebellum-ventral intermediate nucleus circuit. The cortico–striato–pallidal loop is responsible for mediating pallidi-associated sleep disorders. Medication and deep brain stimulation are the primary therapeutic strategies addressing the globus pallidus in Parkinson's disease. Medication is the primary treatment for motor symptoms in the early stages of Parkinson's disease, while deep brain stimulation has been clinically proven to be effective in alleviating symptoms in patients with advanced Parkinson's disease,particularly for the movement disorders caused by levodopa. Deep brain stimulation targeting the globus pallidus internus can improve motor function in patients with tremordominant and non-tremor-dominant Parkinson's disease, while deep brain stimulation targeting the globus pallidus externus can alter the temporal pattern of neural activity throughout the basal ganglia–thalamus network. Therefore, the composition of the globus pallidus neurons, th
基金supported in part by the National Natural Science Foundation of China(No.62273193)Tsinghua University-Meituan Joint Institute for Digital Life,and the Research and Development Project of CRSC Research&Design Institute Group Co.,Ltd.
文摘On-demand food delivery(OFD)is gaining more and more popularity in modern society.As a kernel order assignment manner in OFD scenario,order recommendation directly influences the delivery efficiency of the platform and the delivery experience of riders.This paper addresses the dynamism of the order recommendation problem and proposes a reinforcement learning solution method.An actor-critic network based on long short term memory(LSTM)unit is designed to deal with the order-grabbing conflict between different riders.Besides,three rider sequencing rules are accordingly proposed to match different time steps of the LSTM unit with different riders.To test the performance of the proposed method,extensive experiments are conducted based on real data from Meituan delivery platform.The results demonstrate that the proposed reinforcement learning based order recommendation method can significantly increase the number of grabbed orders and reduce the number of order-grabbing conflicts,resulting in better delivery efficiency and experience for the platform and riders.
基金financially supported by the Natural Science Foundation of China(Grant Nos.52372226,52173263,62004167)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant Nos.2022JM-315,2023-JC-QN-0643)+4 种基金the National Key R&D Program of China(Grant No.2022YFB3603703)the Qinchuangyuan High-level Talent Project of Shaanxi(Grant No.QCYRCXM-2022-219)the Ningbo Natural Science Foundation(Grant No.2022J061)the Key Research and Development Program of Shaanxi(Grant No.2023GXLH-091)the Shccig-Qinling Program and the Fundamental Research Funds for the Central Universities。
文摘Two-dimensional Ruddlesden-Popper(2DRP)perovskite exhibits excellent stability in perovskite solar cells(PSCs)due to introducing hydrophobic long-chain organic spacers.However,the poor charge transporting property of bulky organic cation spacers limits the performance of 2DRP PSCs.Inspired by the Asite cation alloying strategy in 3D perovskites,2DRP perovskites with a binary spacer can promote charge transporting compared to the unary spacer counterparts.Herein,the superior MA-based 2DRP perovskite films with a binary spacer,including 3-guanidinopropanoic acid(GPA)and 4-fluorophenethylamine(FPEA)are realized.These films(GPA_(0.85)FPEA_(0.15))_(2)MA_(4)Pb_5I_(16)show good morphology,large grain size,decreased trap state density,and preferential orientation of the as-prepared film.Accordingly,the present 2DRP-based PSC with the binary spacer achieves a remarkable efficiency of 18.37%with a V_(OC)of1.15 V,a J_(SC)of 20.13 mA cm^(-2),and an FF of 79.23%.To our knowledge,the PCE value should be the highest for binary spacer MA-based 2DRP(n≤5)PSCs to date.Importantly,owing to the hydrophobic fluorine group of FPEA and the enhanced interlayer interaction by FPEA,the unencapsulated 2DRP PSCs based on binary spacers exhibit much excellent humidity stability and thermal stability than the unary spacer counterparts.
基金National Key R&D Program of China(No.2020AAA0108702)National Natural Science Foundation of China(Grant No.62022027).
文摘With current success of large-scale pre-trained models(PTMs),how efficiently adapting PTMs to downstream tasks has attracted tremendous attention,especially for PTMs with billions of parameters.Previous work focuses on designing parameter-efficient tuning paradigms but needs to save and compute the gradient of the whole computational graph.In this paper,we propose y-Tuning,an efficient yet effective paradigm to adapt frozen large-scale PTMs to specific downstream tasks.y-Tuning learns dense representations for labels y defined in a given task and aligns them to fixed feature representation.Without computing the gradients of text encoder at training phrase,y-Tuning is not only parameterefficient but also training-efficient.Experimental results show that for DeBERTaxxL with 1.6 billion parameters,y-Tuning achieves performance more than 96%of full fine-tuning on GLUE Benchmark with only 2%tunable parameters and much fewer training costs.
基金supported by grants from the Natural Science Foundation of Tianjin(21JCZDJC00060,China)the National Nature Science Foundation of China(81973356,91957120,81902826,and 81672781)+4 种基金the Fundamental Research Funds for the Central Universities of Nankai University(3206054,91923101,63213082 and 92122017,China)the State Key Laboratory of Drug Research(SIMM2105KF-08,China)the National Key R&D Program of China(No.2018YFC2002000)the Innovative S&T Projects for Young Researchers of Tianjin Academy of Agricultural Science(grant No.201918,China)the Natural Science Foundation of Tianjin(19JCYBJC29600 and 21JCYBJC00180,China)。
文摘Metabolic reprogramming is a hallmark of cancer,including lung cancer.However,the exact underlying mechanism and therapeutic potential are largely unknown.Here we report that protein arginine methyltransferase 6(PRMT6)is highly expressed in lung cancer and is required for cell metabolism,tumorigenicity,and cisplatin response of lung cancer.PRMT6 regulated the oxidative pentose phosphate pathway(PPP)flux and glycolysis pathway in human lung cancer by increasing the activity of 6-phosphogluconate dehydrogenase(6PGD)and a-enolase(ENO1).Furthermore,PRMT6 methylated R324 of 6PGD to enhancing its activity;while methylation at R9 and R372 of ENO1 promotes formation of active ENO1 dimers and 2-phosphoglycerate(2-PG)binding to ENO1,respectively.Lastly,targeting PRMT6 blocked the oxidative PPP flux,glycolysis pathway,and tumor growth,as well as enhanced the antitumor effects of cisplatin in lung cancer.Together,this study demonstrates that PRMT6 acts as a posttranslational modification(PTM)regulator of glucose metabolism,which leads to the pathogenesis of lung cancer.It was proven that the PRMT6-6PGD/ENO1 regulatory axis is an important determinant of carcinogenesis and may become a promising cancer therapeutic strategy.
基金This work is supported by the National Natural Science Foundation of China(NSFC)(61975090,62175127)by the Tsinghua University Initiative Scientific Research Program(20211080080,2022108006)by the Tsinghua-Toyota Joint Research Fund.
文摘Multimode fiber(MMF)lasers are emerging as a remarkable testbed to study nonlinear spatiotemporal physics with potential applications spanning from high energy pulse generation,precision measurement to nonlinear microscopy.The underlying mechanism for the generation of ultrashort pulses,which can be understood as a spatiotempoal dissipative soliton(STDS),in the nonlinear multimode resonators is the spatiotemporal mode-locking(STML)with simultaneous synchronization of temporal and spatial modes.In this review,we first introduce the general principles of STML,with an emphasize on the STML dynamics with large intermode dispersion.Then,we present the recent progress of STML,including measurement techniques for STML,exotic nonlinear dynamics of STDS,and mode field engineering in MMF lasers.We conclude by outlining some perspectives that may advance STML in the near future.
基金supported by grants from Shenzhen Key Medical Subject(No.SZXK023)Shenzhen“SanMing”Project of Medicine(No.SZSM201612092)+3 种基金Shenzhen Research and Development Projects(No.JCYJ20170307111755218)Guangdong Basic and Applied Basic Research Foundation(No.2019A1515011290)National Key Research and Development Program of China(No.2016YFC1102103)China Postdoctoral Science Foundation(No.2020M672756)
文摘Interconnectivity is the key characteristic of bone tissue engineering scaffold modulating cell migration,blood vessels invasion and transport of nutrient and waste.However,efforts and understanding of the interconnectivity of porous Mg is limited due to the diverse architectures of pore struts and pore size distribution of Mg scaffold systems.In this work,biomimetic hierarchical porous Mg scaffolds with tailored interconnectivity as well as pore size distribution were prepared by template replication of infiltration casting.Mg scaffold with better interconnectivity showed lower mechanical strength.Enlarging interconnected pores would enhance the interconnectivity of the whole scaffold and reduce the change of ion concentration,pH value and osmolality of the degradation microenvironment due to the lower specific surface area.Nevertheless,the degradation rates of five tested Mg scaffolds were no different because of the same geometry of strut unit.Direct cell culture and evaluation of cell density at both sides of four typical Mg scaffolds indicated that cell migration through hierarchical porous Mg scaffolds could be enhanced by not only bigger interconnected pore size but also larger main pore size.In summary,design of interconnectivity in terms of pore size distribution could regulate mechanical strength,microenvironment in cell culture condition and cell migration potential,and beyond that it shows great potential for personalized therapy which could facilitate the regeneration process.
基金supported by National Natural Science Foundation of China (81530042, 31571529, 31210103905, 31571519, 31571390, 31371510, 31301208, 31471250, 31401257)the Ministry of Science and Technology (2012CB966603, 2013CB967600, 2013CB967401)+2 种基金Science and Technology Commission of Shanghai Municipality (15JC1403200, 15JC1403201)Shanghai Rising-Star Program (14QA1403900)the Fundamental Research Funds for the Central Universities (2000219099)
文摘In vitro, mouse embryonic stem （ES） cells can differentiate into many somatic cell types, including neurons and glial cells. When cultured in serum-free medium, ES cells convert spontaneously and efficiently to a neural fate. Previous studies have shown that the neural conversion of mouse ES cells includes both the participation of neural-specific transcription factors and the regulation of epigenetic modifications. However, the intracellular mechanism underlying this intrinsic transition still re- mains to be further elucidated. Herein, we describe a long intergenic non-coding RNA, LincRNA1230, which participates in the regulation of the neural lineage specification of mouse ES cells. The ectopic forced expression of LincRNAI230 dramatically inhibited mouse ES cells from adopting a neural cell fate, while LincRNA1230 knockdown promoted the conversion of mouse ES cells towards neural progenitors. Mechanistic studies have shown that LincRNA1230 inhibits the activation of early neural genes, such as Pax6 and Soxl, through the modulation of bivalent modifications （tri-methylation of histone3 lysine4 and his- tone3 lysine27） at the promoters of these genes. The interaction of LincRNA1230 with Wdr5 blocked the localization of Wdr5 at the promoters of early neural genes, thereby inhibiting the enrichment of H3K4me3 modifications at these loci. Collectively, these findings revealed a crucial role for LincRNA1230 in the regulation of the neural differentiation of mouse ES cells.
