Disseminated intravascular coagulation (DIC)is a clinical syndrome caused by various etiologies and characterized by systemic activation of blood coagulation,leading to vessel thrombosis,organ dysfunction,and severe b...Disseminated intravascular coagulation (DIC)is a clinical syndrome caused by various etiologies and characterized by systemic activation of blood coagulation,leading to vessel thrombosis,organ dysfunction,and severe bleeding.^([1])DIC represents a life-threatening condition that is the endpoint of uncontrolled systemic activation of the disease.Once it enters the stage of malignant DIC,the patient’s death becomes unavoidable.DIC always occurs as a secondary disorder and is commonly associated with postpartum hemorrhage,followed by hypertensive disorders,acute fatty liver of pregnancy,sepsis,and amniotic fluid embolism (AFE).^([2])In clinical obstetrics,DIC often occurs during delivery or postpartum.展开更多
Limited lithium resources have promoted the exploration of new battery technologies.Among them,potassium-ion batteries are considered as promising alternatives.At present,commercial graphite and other carbon-based mat...Limited lithium resources have promoted the exploration of new battery technologies.Among them,potassium-ion batteries are considered as promising alternatives.At present,commercial graphite and other carbon-based materials have shown good prospects as anodes for potassium-ion batteries.However,the volume expansion and structural collapse caused by periodic K+insertion/extraction have severely restricted further development and application of potassium-ion batteries.A hollow biomass carbon ball(NOP-PB)ternarily doped with N,O,and P was synthesized and used as the negative electrode of a potassium-ion battery.X-ray photoelectron spectroscopy,Fourier‐transform infrared spectroscopy,and transmission electron microscopy confirmed that the hollow biomass carbon spheres were successfully doped with N,O,and P.Further analysis proved that N,O,and P ternary doping expands the interlayer distance of the graphite surface and introduces more defect sites.DFT calculations simultaneously proved that the K adsorption energy of the doped structure is greatly improved.The solid hollow hierarchical porous structure buffers the volume expansion of the potassium insertion process,maintains the original structure after a long cycle and promotes the transfer of potassium ions and electrons.Therefore,the NOP‐PB negative electrode shows extremely enhanced electrochemical performance,including high specific capacity,excellent long‐term stability,and good rate stability.展开更多
Ceramic fibrous aerogels are highly desirable for thermal management materials due to their high porosity,excellent elasticity,thermal conductivity,and good thermal resistance.However,the fabrication of nanofibrous ae...Ceramic fibrous aerogels are highly desirable for thermal management materials due to their high porosity,excellent elasticity,thermal conductivity,and good thermal resistance.However,the fabrication of nanofibrous aerogel with super-elasticity and good shape retention at the same time has remained challenging.To meet the requirements,a novel anisotropy nanofibrous-granular aerogel with a quasi-layered multi-arch-like and hierarchical-cellular structure is designed and prepared by vacuum-filtration-assisted freeze-drying and sintering.The quasi-layered multi-arch and flexible nanofibers endowed the aerogels with excellent mechanical robustness(ultimate stress up to 60 kPa with strain 60%)and super-elasticity with recoverable compression strain up to 60%.The introduced SiO_(2) aerogel nanoparticles and nanofibers are assembled into an arch-like structure and become the connection point of adjacent nanofibers,which endows low thermal conductivity(0.024 mW/(m·K))of composite aerogel.This novel strategy provides a fresh perspective for the preparation of nanofibrous aerogel with robust mechanical in thermal insulation and other fields.展开更多
Flash sintering(FS)is a novel technique for rapidly densifying silicon carbide(SiC)ceramics.This work achieved a rapid sintering of SiC ceramics by the utilization of ultra-high temperature flash sintering within 60 s...Flash sintering(FS)is a novel technique for rapidly densifying silicon carbide(SiC)ceramics.This work achieved a rapid sintering of SiC ceramics by the utilization of ultra-high temperature flash sintering within 60 s.Pyrolysis carbon(PyC)“bridges”were constructed between SiC particles through the carbonisation of phenolic resin,providing a large number of current channels.The incubation time of the flash sintering process was significantly reduced,and the sintering difference between the centre and the edge regions of the ceramics was minimized,with an average particle size of the centre region and edge region being 12.31 and 9.02μm,respectively.The results showed that the porosity of the SiC ceramics after the flash sintering was reduced to 14.79% with PyC“bridges”introduced,and the Vickers hardness reached 19.62 GPa.PyC“bridges”gradually evolved from amorphous eddy current carbon to oriented graphite carbon,indicating that the ultra-high temperature environment in which the sample was located during the flash sintering was successfully constructed.Ultra-high temperature flash sintering of SiC is expected to be applied to the local repair of matrix damage in SiC ceramic matrix composites.展开更多
In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great attention.However,the stability and oxi...In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great attention.However,the stability and oxidation/corrosion resistance of PDCs cannot be simultaneously achieved at the moment,limiting their practical application.Herein,polymer-derived SiAlBCN ceramics were synthesized via polymer conversion method under different pyrolysis temperatures.Their microstructure evolution,high temperature sensing properties,and stability were investigated in detail.The results show that the amorphous SiAlBCN phase grows more orderly and the size of the free carbon phase enlarges with the increasing temperature.The defect concentration displays a decreasing tendency.Concurrently,the SiAlBCN ceramics as sensing materials exhibit a good temperature-resistance property from roo temperature to 1100℃.The fabricated SiAlBCN temperature sensor possesses excellent stability,repeatability,and accuracy.Moreover,SiAlBCN ceramics exhibit distinguished oxidation/corrosion resistance after 100 h treatment at 1200℃in a water/oxygen environment,which is attributed to their low corrosive rate constant(0.57 mg/(cm^(2)·h))and oxidative rate constant(3.43 mg^(2)/(cm^(4)·h)).Therefore,polymer-derived SiAlBCN ceramics as sensing materials,which possess outstanding stability and oxidation/corrosion resistance,have great potential for in-situ monitoring of extreme environmental temperatures in the future.展开更多
基于二维材料范德华异质结的自驱动光电探测器是逻辑光电子器件和智能图像传感器的重要组成部分.本文通过机械剥离和干法转移制备了一种底部Au接触的PtSe_(2)/WSe_(2)/Au非对称肖特基光电二极管.栅极可调的Au/WSe_(2)肖特基势垒大小、...基于二维材料范德华异质结的自驱动光电探测器是逻辑光电子器件和智能图像传感器的重要组成部分.本文通过机械剥离和干法转移制备了一种底部Au接触的PtSe_(2)/WSe_(2)/Au非对称肖特基光电二极管.栅极可调的Au/WSe_(2)肖特基势垒大小、弱费米钉扎效应、高半金属PtSe_(2)导电率以及良好的PtSe_(2)/WSe_(2)层间耦合效应使得该二极管产生极性可重构现象,可实现栅极可调正负整流行为,且整流比变化范围在10−2到104之间,达到6个量级.我们利用此特性验证了半波逻辑整流器功能.此外,此自驱动器件的最大光响应度达316 mA W^(−1),最大光开关比达105,光电转换效率为4.62%,响应时间仅为830/950μs.光电流微区扫描结果表明,器件的光电流主要分布在Au/WSe_(2)界面边缘,证实该器件为非对称肖特基光电二极管.该器件还实现了高分辨率的可见光单点成像.上述研究结果表明,本工作为制备高性能半波整流器、超快自驱动光电探测器和高分辨图像传感器提供了一种简便有效的策略.展开更多
A thermally induced hexagonal close-packed(HCP)to face-centered cubic(FCC)phase transition was investigated in anα-type Ti35 alloy with twinned structure by in situ heating transmission electron microscopy(TEM)and ab...A thermally induced hexagonal close-packed(HCP)to face-centered cubic(FCC)phase transition was investigated in anα-type Ti35 alloy with twinned structure by in situ heating transmission electron microscopy(TEM)and ab initio calculations.TEM observations indicated that the HCP to FCC phase transition occurred both within matrix/twin and at the twin boundaries in the thinner region of the TEM film,and the FCC-Ti precipitated as plates within the matrix/twin,while as equiaxed cells at twin boundaries.The crystallographic orientation relationship between HCP-Ti and FCC-Ti can be described as:{111}FCC//{0002}HCP and<110>FCC//<1210>HCP.The HCP to FCC phase transition was accomplished by forming an intermediate state with a BB stacking sequence through the slip of partial dislocations.The formation of such FCC-Ti may be related to the thermal stress and temperature.Ab initio calculations showed that the formation of FCC-Ti may also be related to the contamination of interstitial atoms such as oxygen.展开更多
With the development of information technology,a mass of data are generated every day.Collecting and analysing these data help service providers improve their services and gain an advantage in the fierce market compet...With the development of information technology,a mass of data are generated every day.Collecting and analysing these data help service providers improve their services and gain an advantage in the fierce market competition.K-means clustering has been widely used for cluster analysis in real life.However,these analyses are based on users’data,which disclose users’privacy.Local differential privacy has attracted lots of attention recently due to its strong privacy guarantee and has been applied for clustering analysis.However,existing K-means clustering methods with local differential privacy protection cannot get an ideal clustering result due to the large amount of noise introduced to the whole dataset to ensure the privacy guarantee.To solve this problem,we propose a novel method that provides local distance privacy for users who participate in the clustering analysis.Instead of making the users’records in-distinguish from each other in high-dimensional space,we map the user’s record into a one-dimensional distance space and make the records in such a distance space not be distinguished from each other.To be specific,we generate a noisy distance first and then synthesize the high-dimensional data record.We propose a Bounded Laplace Method(BLM)and a Cluster Indistinguishable Method(CIM)to sample such a noisy distance,which satisfies the local differential privacy guarantee and local dE-privacy guarantee,respectively.Furthermore,we introduce a way to generate synthetic data records in high-dimensional space.Our experimental evaluation results show that our methods outperform the traditional methods significantly.展开更多
Engineering of defects in semiconductors provides an effective protocol for improving photocatalytic N_(2) conversion efficiency.This review focuses on the state-of-the-art progress in defect engineering of photocatal...Engineering of defects in semiconductors provides an effective protocol for improving photocatalytic N_(2) conversion efficiency.This review focuses on the state-of-the-art progress in defect engineering of photocatalysts for the N_(2) reduction toward ammonia.The basic principles and mechanisms of thermal catalyzed and photon-induced N_(2) reduction are first concisely recapped,including relevant properties of the N_(2) molecule,reaction pathways,and NH3 quantification methods.Subsequently,defect classification,synthesis strategies,and identification techniques are compendiously summarized.Advances of in situ characterization techniques for monitoring defect state during the N_(2) reduction process are also described.Especially,various surface defect strategies and their critical roles in improving the N_(2) photoreduction performance are highlighted,including surface vacancies(i.e.,anionic vacancies and cationic vacancies),heteroatom doping(i.e.,metal element doping and nonmetal element doping),and atomically defined surface sites.Finally,future opportunities and challenges as well as perspectives on further development of defect-engineered photocatalysts for the nitrogen reduction to ammonia are presented.It is expected that this review can provide a profound guidance for more specialized design of defect-engineered catalysts with high activity and stability for nitrogen photochemical fixation.展开更多
Updating high-definition maps is imperative for the safety of autonomous vehicles.However,positional changes in lane lines are hard to be detected in a timely manner due to a limited number of expensive surveying vehi...Updating high-definition maps is imperative for the safety of autonomous vehicles.However,positional changes in lane lines are hard to be detected in a timely manner due to a limited number of expensive surveying vehicles over a large geo-graphic area.Herein,a novel method is proposed to detect the geometric changes of lane lines using low-cost sensors,such as consumer-grade global navigation satellite system(GNSS)hardware receivers and cameras.The proposed framework geometric change detection using low-cost sensors(GCD-L)and algorithm change segment compare(CSC),which are based on the lane width between the curb line and the adjacent leftmost lane line,can perceive the positional changes of the leftmost lane line on highway and expressway roads.The effectiveness of the proposed method is verified by evaluating it on a real-world typical urban ring road dataset.The experimental results show that 71%detected change segments are valid with only two round crowdsourced maps.展开更多
Background:Following initiation of China’s National Malaria Elimination Action Plan(NMEAP)in 2010,the'1-3-7’approach was developed and rolled out in China to facilitate the malaria elimination programme and acce...Background:Following initiation of China’s National Malaria Elimination Action Plan(NMEAP)in 2010,the'1-3-7’approach was developed and rolled out in China to facilitate the malaria elimination programme and accelerate malaria elimination.This study aims to summarize and condense these experiences through a retrospective analysis in Jiangsu Province,which could be adapted and applied in other malaria elimination settings worldwide.Methods:A retrospective analysis of imported malaria cases into China identified through an improved surveillance and response system in Jiangsu Province was carried out for the period of 2001-2020.To improve the malaria surveillance and response system,Centers for Diseases Control and Prevention from the prefectures and counties in Jiangsu province conducted population-level health education to improve healthcare seeking behavior,strengthened capacity of health facilities to improve performance of malaria diagnosis and treatment,and raised the capacity of public health providers to improve implementation of the'1-3-7’approach.Categorical variables were carried out by Chi square tests with Fisher’s exact correction.Results:From 2001 to 2020,a total of 9,879 malaria cases were reported in Jiangsu Province.Since 2012,no indigenous malaria cases have been reported in Jiangsu Province.However,in recent years,there has been a substantial increase of imported falciparum malaria cases.Between 2012 and 2020,an estimated 61.57 million individuals have benefited from population-level health education in Jiangsu Province.For healthcare-seeking services among the 2,423 imported malaria cases,687(28.4%)and 1,104(45.6%)cases visited hospitals on the first day and the second day from symptom onset,respectively.A total of 1,502(61.9%)cases were diagnosed on the first day at medical facilities.Jiangsu Province achieved 100%,99.4%and 98.3%completion rate in terms of case detection and notification(within one day),case investigation(within three days)and foci response and disposition(within seven days),respectively.The improved surveillance and response system in Jiangsu Province plays an important role in preventing the re-introduction of malaria and maintaining the malaria-free status.Conclusions:Jiangsu Province has maintained its malaria-free status since 2012.The continuous improvement of a surveillance and response system plays an important role in the early detection and rapid response of potential malaria-related outbreaks in Jiangsu,China,and has important lessons for other malaria eliminating settings.Remaining vigilant in the detection of imported malaria cases and maintaining an active surveillance and response system is critical to sustain the success of malaria elimination.展开更多
High-definition map has become a vital cornerstone in the navigation of autonomous vehicles in complex traffic scenarios.Thus,the construction of high-definition maps has become crucial.Traditional methods relying on ...High-definition map has become a vital cornerstone in the navigation of autonomous vehicles in complex traffic scenarios.Thus,the construction of high-definition maps has become crucial.Traditional methods relying on expensive mapping vehicles equipped with high-end sensor equipment are not suitable for mass map construction because of the limitation imposed by its high cost.Hence,this paper proposes a new method to create a high-definition road semantics map using multi-vehicle sensor data.The proposed method implements crowdsourced point-based visual SLAM to align and combine the local maps derived by multiple vehicles.This allows users to modify the extraction process by using a more sophisticated neural network,thus achieving a more accurate detection result when compared with traditional binarization method.The resulting map consists of road marking points suitable for autonomous vehicle navigation and path-planning tasks.Finally,the method is evaluated on the real-world KAIST urban dataset and Shougang dataset to demonstrate the level of detail and accuracy of the proposed map with 0.369 m in mapping errors in ideal condition.展开更多
Real driving scenarios,due to occlusions and disturbances,provide disordered and noisy measurements,which makes the task of multi-object tracking quite challenging.Conventional approach is to find deterministic data a...Real driving scenarios,due to occlusions and disturbances,provide disordered and noisy measurements,which makes the task of multi-object tracking quite challenging.Conventional approach is to find deterministic data association;however,it has unstable performance in high clutter density.This paper proposes a novel probabilistic tracklet-enhanced multiple object tracker(PTMOT),which integrates Poisson multi-Bernoulli mixture(PMBM)filter with confidence of tracklets.The proposed method is able to realize efficient and robust probabilistic association for 3D multi-object tracking(MOT)and improve the PMBM filter’s continuity by smoothing single target hypothesis with global hypothesis.It consists of two key parts.First,the PMBM tracker based on sets of tracklets is implemented to realize probabilistic fusion of disordered measure-ments.Second,the confidence of tracklets is smoothed through a smoothing-while-filtering approach.Extensive MOT tests on nuScenes tracking dataset demonstrate that the proposed method achieves superior performance in different modalities.展开更多
Circular single-stranded DNA(ssDNA)viruses have been rarely found in fungi,and the evolutionary and ecological relationships among ssDNA viruses infecting fungi and other organisms remain unclear.In this study,a novel...Circular single-stranded DNA(ssDNA)viruses have been rarely found in fungi,and the evolutionary and ecological relationships among ssDNA viruses infecting fungi and other organisms remain unclear.In this study,a novel circular ssDNA virus,tentatively named Diaporthe sojae circular DNA virus 1(DsCDV1),was identified in the phytopathogenic fungus Diaporthe sojae isolated from pear trees.DsCDV1 has a monopartite genome(3185 nt in size)encapsidated in isometric virions(21-26 nm in diameter).The genome comprises seven putative open reading frames encoding a discrete replicase(Rep)split by an intergenic region,a putative capsid protein(CP),several proteins of unknown function(P1-P4),and a long intergenic region.Notably,the two split parts of DsCDV1 Rep share high identities with the Reps of Geminiviridae and Genomoviridae,respectively,indicating an evolutionary linkage with both families.Phylogenetic analysis based on Rep or CP sequences placed DsCDV1 in a unique cluster,supporting the establishment of a new family,tentatively named Gegemycoviridae,intermediate to both families.DsCDV1 significantly attenuates fungal growth and nearly erases fungal virulence when transfected into the host fungus.Remarkably,DsCDV1 can systematically infect tobacco and pear seedlings,providing broad-spectrum resistance to fungal diseases.Subcellular localization analysis revealed that DsCDV1 P3 is systematically localized in the plasmodesmata,while its expression in trans-complementation experiments could restore systematic infection of a movement-deficient plant virus,suggesting that P3 is a movement protein.DsCDV1 exhibits unique molecular and biological traits not observed in other ssDNA viruses,serving as a link between fungal and plant ssDNA viruses and presenting an evolutionary connection between ssDNA viruses and fungi.These findings contribute to expanding our understanding of ssDNA virus diversity and evolution,offering potential biocontrol applications for managing crucial plant diseases.展开更多
基金supported by a grant from Scientific Research Foundation of the National Health Commission (WKJ-ZJ-2126)。
文摘Disseminated intravascular coagulation (DIC)is a clinical syndrome caused by various etiologies and characterized by systemic activation of blood coagulation,leading to vessel thrombosis,organ dysfunction,and severe bleeding.^([1])DIC represents a life-threatening condition that is the endpoint of uncontrolled systemic activation of the disease.Once it enters the stage of malignant DIC,the patient’s death becomes unavoidable.DIC always occurs as a secondary disorder and is commonly associated with postpartum hemorrhage,followed by hypertensive disorders,acute fatty liver of pregnancy,sepsis,and amniotic fluid embolism (AFE).^([2])In clinical obstetrics,DIC often occurs during delivery or postpartum.
基金The authors are grateful for support from the National Natural Science Foundation of China(No.21671160).
文摘Limited lithium resources have promoted the exploration of new battery technologies.Among them,potassium-ion batteries are considered as promising alternatives.At present,commercial graphite and other carbon-based materials have shown good prospects as anodes for potassium-ion batteries.However,the volume expansion and structural collapse caused by periodic K+insertion/extraction have severely restricted further development and application of potassium-ion batteries.A hollow biomass carbon ball(NOP-PB)ternarily doped with N,O,and P was synthesized and used as the negative electrode of a potassium-ion battery.X-ray photoelectron spectroscopy,Fourier‐transform infrared spectroscopy,and transmission electron microscopy confirmed that the hollow biomass carbon spheres were successfully doped with N,O,and P.Further analysis proved that N,O,and P ternary doping expands the interlayer distance of the graphite surface and introduces more defect sites.DFT calculations simultaneously proved that the K adsorption energy of the doped structure is greatly improved.The solid hollow hierarchical porous structure buffers the volume expansion of the potassium insertion process,maintains the original structure after a long cycle and promotes the transfer of potassium ions and electrons.Therefore,the NOP‐PB negative electrode shows extremely enhanced electrochemical performance,including high specific capacity,excellent long‐term stability,and good rate stability.
基金supported by the National Natural Science Foundation of China(No.U2167214)the Science and Technology International Cooperation Project of Jiangsu(No.BZ2021055)+1 种基金the Industry Foresight and Key Core Technology Competition Project of Jiangsu(No.BE2022147)the Overseas Professor Project(No.G2022181024L).
文摘Ceramic fibrous aerogels are highly desirable for thermal management materials due to their high porosity,excellent elasticity,thermal conductivity,and good thermal resistance.However,the fabrication of nanofibrous aerogel with super-elasticity and good shape retention at the same time has remained challenging.To meet the requirements,a novel anisotropy nanofibrous-granular aerogel with a quasi-layered multi-arch-like and hierarchical-cellular structure is designed and prepared by vacuum-filtration-assisted freeze-drying and sintering.The quasi-layered multi-arch and flexible nanofibers endowed the aerogels with excellent mechanical robustness(ultimate stress up to 60 kPa with strain 60%)and super-elasticity with recoverable compression strain up to 60%.The introduced SiO_(2) aerogel nanoparticles and nanofibers are assembled into an arch-like structure and become the connection point of adjacent nanofibers,which endows low thermal conductivity(0.024 mW/(m·K))of composite aerogel.This novel strategy provides a fresh perspective for the preparation of nanofibrous aerogel with robust mechanical in thermal insulation and other fields.
基金supported by the National Natural Science Foundation of China(No.92160202)the National Natural Science Foundation of China(No.52375188)+1 种基金the National Key R&D Program of China(No.2021YFB3703100)the Ningbo Key Technology Research and Development(No.2023T007).
文摘Flash sintering(FS)is a novel technique for rapidly densifying silicon carbide(SiC)ceramics.This work achieved a rapid sintering of SiC ceramics by the utilization of ultra-high temperature flash sintering within 60 s.Pyrolysis carbon(PyC)“bridges”were constructed between SiC particles through the carbonisation of phenolic resin,providing a large number of current channels.The incubation time of the flash sintering process was significantly reduced,and the sintering difference between the centre and the edge regions of the ceramics was minimized,with an average particle size of the centre region and edge region being 12.31 and 9.02μm,respectively.The results showed that the porosity of the SiC ceramics after the flash sintering was reduced to 14.79% with PyC“bridges”introduced,and the Vickers hardness reached 19.62 GPa.PyC“bridges”gradually evolved from amorphous eddy current carbon to oriented graphite carbon,indicating that the ultra-high temperature environment in which the sample was located during the flash sintering was successfully constructed.Ultra-high temperature flash sintering of SiC is expected to be applied to the local repair of matrix damage in SiC ceramic matrix composites.
基金the National Key R&D Program of China(No.2021YFB3200500)the National Natural Science Foundation of China(Nos.52072344 and U1904180)+1 种基金the Excellent Young Scientists Fund of Henan Province(No.202300410369)the Henan Province University Innovation Talents Support Program(No.21HASTIT001).
文摘In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great attention.However,the stability and oxidation/corrosion resistance of PDCs cannot be simultaneously achieved at the moment,limiting their practical application.Herein,polymer-derived SiAlBCN ceramics were synthesized via polymer conversion method under different pyrolysis temperatures.Their microstructure evolution,high temperature sensing properties,and stability were investigated in detail.The results show that the amorphous SiAlBCN phase grows more orderly and the size of the free carbon phase enlarges with the increasing temperature.The defect concentration displays a decreasing tendency.Concurrently,the SiAlBCN ceramics as sensing materials exhibit a good temperature-resistance property from roo temperature to 1100℃.The fabricated SiAlBCN temperature sensor possesses excellent stability,repeatability,and accuracy.Moreover,SiAlBCN ceramics exhibit distinguished oxidation/corrosion resistance after 100 h treatment at 1200℃in a water/oxygen environment,which is attributed to their low corrosive rate constant(0.57 mg/(cm^(2)·h))and oxidative rate constant(3.43 mg^(2)/(cm^(4)·h)).Therefore,polymer-derived SiAlBCN ceramics as sensing materials,which possess outstanding stability and oxidation/corrosion resistance,have great potential for in-situ monitoring of extreme environmental temperatures in the future.
基金supported by the National Natural Science Foundation of China(62175040 and 61805044)the Science and Technology Program of Guangzhou(202201010242)+1 种基金Guangdong Provincial Key Laboratory of Information Photonics Technology(2020B121201011)the Pearl River Talent Recruitment Program(2019ZT08X639)。
基金supported by the National Natural Science Foundation of China (62004071, 62074060, and 62175040)the Science and Technology Program of Guangzhou (202103030001)“The Pearl River Talent Recruitment Program” (2019ZT08X639)
文摘基于二维材料范德华异质结的自驱动光电探测器是逻辑光电子器件和智能图像传感器的重要组成部分.本文通过机械剥离和干法转移制备了一种底部Au接触的PtSe_(2)/WSe_(2)/Au非对称肖特基光电二极管.栅极可调的Au/WSe_(2)肖特基势垒大小、弱费米钉扎效应、高半金属PtSe_(2)导电率以及良好的PtSe_(2)/WSe_(2)层间耦合效应使得该二极管产生极性可重构现象,可实现栅极可调正负整流行为,且整流比变化范围在10−2到104之间,达到6个量级.我们利用此特性验证了半波逻辑整流器功能.此外,此自驱动器件的最大光响应度达316 mA W^(−1),最大光开关比达105,光电转换效率为4.62%,响应时间仅为830/950μs.光电流微区扫描结果表明,器件的光电流主要分布在Au/WSe_(2)界面边缘,证实该器件为非对称肖特基光电二极管.该器件还实现了高分辨率的可见光单点成像.上述研究结果表明,本工作为制备高性能半波整流器、超快自驱动光电探测器和高分辨图像传感器提供了一种简便有效的策略.
基金supported by the Natural Science Foundation of Shanghai(Grant No.21ZR1445100)the National Natural Science Foundation of China(Grant No.52271108)+2 种基金the Foundation of Xi'an Key Laboratory of High-Performance Titanium Alloy(Grant No.NIN-HTL-2022-02)financial support from the Frontier and Key Projects of the Chinese Academy of Sciences(Grant No.QYZDJ-SSW-JSC031-01)financial support from Xi’an Science and Technology Plan Project(Grant No.2020YZ0028).
文摘A thermally induced hexagonal close-packed(HCP)to face-centered cubic(FCC)phase transition was investigated in anα-type Ti35 alloy with twinned structure by in situ heating transmission electron microscopy(TEM)and ab initio calculations.TEM observations indicated that the HCP to FCC phase transition occurred both within matrix/twin and at the twin boundaries in the thinner region of the TEM film,and the FCC-Ti precipitated as plates within the matrix/twin,while as equiaxed cells at twin boundaries.The crystallographic orientation relationship between HCP-Ti and FCC-Ti can be described as:{111}FCC//{0002}HCP and<110>FCC//<1210>HCP.The HCP to FCC phase transition was accomplished by forming an intermediate state with a BB stacking sequence through the slip of partial dislocations.The formation of such FCC-Ti may be related to the thermal stress and temperature.Ab initio calculations showed that the formation of FCC-Ti may also be related to the contamination of interstitial atoms such as oxygen.
文摘With the development of information technology,a mass of data are generated every day.Collecting and analysing these data help service providers improve their services and gain an advantage in the fierce market competition.K-means clustering has been widely used for cluster analysis in real life.However,these analyses are based on users’data,which disclose users’privacy.Local differential privacy has attracted lots of attention recently due to its strong privacy guarantee and has been applied for clustering analysis.However,existing K-means clustering methods with local differential privacy protection cannot get an ideal clustering result due to the large amount of noise introduced to the whole dataset to ensure the privacy guarantee.To solve this problem,we propose a novel method that provides local distance privacy for users who participate in the clustering analysis.Instead of making the users’records in-distinguish from each other in high-dimensional space,we map the user’s record into a one-dimensional distance space and make the records in such a distance space not be distinguished from each other.To be specific,we generate a noisy distance first and then synthesize the high-dimensional data record.We propose a Bounded Laplace Method(BLM)and a Cluster Indistinguishable Method(CIM)to sample such a noisy distance,which satisfies the local differential privacy guarantee and local dE-privacy guarantee,respectively.Furthermore,we introduce a way to generate synthetic data records in high-dimensional space.Our experimental evaluation results show that our methods outperform the traditional methods significantly.
基金This work was supported by the National Natural Science Foundation of China(No.21972010)Beijing Natural Science Foundation(No.2192039)+1 种基金the Foundation of Key Laboratory of Low-Carbon Conversion Science&Engineering,Shanghai Advanced Research Institute,the Chinese Academy of Sciences(No.KLLCCSE-201901,SARI,CAS)Beijing University of Chemical Technology(XK180301,XK1804-2).
文摘Engineering of defects in semiconductors provides an effective protocol for improving photocatalytic N_(2) conversion efficiency.This review focuses on the state-of-the-art progress in defect engineering of photocatalysts for the N_(2) reduction toward ammonia.The basic principles and mechanisms of thermal catalyzed and photon-induced N_(2) reduction are first concisely recapped,including relevant properties of the N_(2) molecule,reaction pathways,and NH3 quantification methods.Subsequently,defect classification,synthesis strategies,and identification techniques are compendiously summarized.Advances of in situ characterization techniques for monitoring defect state during the N_(2) reduction process are also described.Especially,various surface defect strategies and their critical roles in improving the N_(2) photoreduction performance are highlighted,including surface vacancies(i.e.,anionic vacancies and cationic vacancies),heteroatom doping(i.e.,metal element doping and nonmetal element doping),and atomically defined surface sites.Finally,future opportunities and challenges as well as perspectives on further development of defect-engineered photocatalysts for the nitrogen reduction to ammonia are presented.It is expected that this review can provide a profound guidance for more specialized design of defect-engineered catalysts with high activity and stability for nitrogen photochemical fixation.
基金sponsored by the National Natural Science Foundation of China-52102426,U1864203 and 61773234the Project Funded by China Postdoctoral Science Foundation-2019M660622.
文摘Updating high-definition maps is imperative for the safety of autonomous vehicles.However,positional changes in lane lines are hard to be detected in a timely manner due to a limited number of expensive surveying vehicles over a large geo-graphic area.Herein,a novel method is proposed to detect the geometric changes of lane lines using low-cost sensors,such as consumer-grade global navigation satellite system(GNSS)hardware receivers and cameras.The proposed framework geometric change detection using low-cost sensors(GCD-L)and algorithm change segment compare(CSC),which are based on the lane width between the curb line and the adjacent leftmost lane line,can perceive the positional changes of the leftmost lane line on highway and expressway roads.The effectiveness of the proposed method is verified by evaluating it on a real-world typical urban ring road dataset.The experimental results show that 71%detected change segments are valid with only two round crowdsourced maps.
基金This study was supported by Bill&Melinda Gates Foundation(INV-018913)the National Natural Science Foundation of China(71904165)+2 种基金the Jiangsu Provincial Department of Science and Technology(BM2018020)the Jiangsu Provincial Health Commission(H2018102,and X201828)the Jiangsu Provincial Project of Invigorating Health Care through Science,Technology,and Education.
文摘Background:Following initiation of China’s National Malaria Elimination Action Plan(NMEAP)in 2010,the'1-3-7’approach was developed and rolled out in China to facilitate the malaria elimination programme and accelerate malaria elimination.This study aims to summarize and condense these experiences through a retrospective analysis in Jiangsu Province,which could be adapted and applied in other malaria elimination settings worldwide.Methods:A retrospective analysis of imported malaria cases into China identified through an improved surveillance and response system in Jiangsu Province was carried out for the period of 2001-2020.To improve the malaria surveillance and response system,Centers for Diseases Control and Prevention from the prefectures and counties in Jiangsu province conducted population-level health education to improve healthcare seeking behavior,strengthened capacity of health facilities to improve performance of malaria diagnosis and treatment,and raised the capacity of public health providers to improve implementation of the'1-3-7’approach.Categorical variables were carried out by Chi square tests with Fisher’s exact correction.Results:From 2001 to 2020,a total of 9,879 malaria cases were reported in Jiangsu Province.Since 2012,no indigenous malaria cases have been reported in Jiangsu Province.However,in recent years,there has been a substantial increase of imported falciparum malaria cases.Between 2012 and 2020,an estimated 61.57 million individuals have benefited from population-level health education in Jiangsu Province.For healthcare-seeking services among the 2,423 imported malaria cases,687(28.4%)and 1,104(45.6%)cases visited hospitals on the first day and the second day from symptom onset,respectively.A total of 1,502(61.9%)cases were diagnosed on the first day at medical facilities.Jiangsu Province achieved 100%,99.4%and 98.3%completion rate in terms of case detection and notification(within one day),case investigation(within three days)and foci response and disposition(within seven days),respectively.The improved surveillance and response system in Jiangsu Province plays an important role in preventing the re-introduction of malaria and maintaining the malaria-free status.Conclusions:Jiangsu Province has maintained its malaria-free status since 2012.The continuous improvement of a surveillance and response system plays an important role in the early detection and rapid response of potential malaria-related outbreaks in Jiangsu,China,and has important lessons for other malaria eliminating settings.Remaining vigilant in the detection of imported malaria cases and maintaining an active surveillance and response system is critical to sustain the success of malaria elimination.
基金supported by the National Natural Science Foundation of China(61805044,62004071 and 11674310)the Key Platforms and Research Projects of Department of Education of Guangdong Province(2018KTSCX050)+1 种基金Guangdong Provincial Key Laboratory of Information Photonics Technology(2020B121201011)"The Pearl River Talent Recruitment Program"(2019ZT08X639)。
基金This work was supported in part by National Natural Science Foundation of China(U186420361773234 and 52102464)Project Funded by China Postdoctoral Science Foundation(2019M660622)in part by the International Science and Technology Cooperation Program of China(2019YFE0100200).
文摘High-definition map has become a vital cornerstone in the navigation of autonomous vehicles in complex traffic scenarios.Thus,the construction of high-definition maps has become crucial.Traditional methods relying on expensive mapping vehicles equipped with high-end sensor equipment are not suitable for mass map construction because of the limitation imposed by its high cost.Hence,this paper proposes a new method to create a high-definition road semantics map using multi-vehicle sensor data.The proposed method implements crowdsourced point-based visual SLAM to align and combine the local maps derived by multiple vehicles.This allows users to modify the extraction process by using a more sophisticated neural network,thus achieving a more accurate detection result when compared with traditional binarization method.The resulting map consists of road marking points suitable for autonomous vehicle navigation and path-planning tasks.Finally,the method is evaluated on the real-world KAIST urban dataset and Shougang dataset to demonstrate the level of detail and accuracy of the proposed map with 0.369 m in mapping errors in ideal condition.
基金supported by International Science and Technology Cooperation Program of China(2019YFE0100200)in part by National Natural Science Foundation of China(61903220)National Natural Science Foundation of China(U1864203).
文摘Real driving scenarios,due to occlusions and disturbances,provide disordered and noisy measurements,which makes the task of multi-object tracking quite challenging.Conventional approach is to find deterministic data association;however,it has unstable performance in high clutter density.This paper proposes a novel probabilistic tracklet-enhanced multiple object tracker(PTMOT),which integrates Poisson multi-Bernoulli mixture(PMBM)filter with confidence of tracklets.The proposed method is able to realize efficient and robust probabilistic association for 3D multi-object tracking(MOT)and improve the PMBM filter’s continuity by smoothing single target hypothesis with global hypothesis.It consists of two key parts.First,the PMBM tracker based on sets of tracklets is implemented to realize probabilistic fusion of disordered measure-ments.Second,the confidence of tracklets is smoothed through a smoothing-while-filtering approach.Extensive MOT tests on nuScenes tracking dataset demonstrate that the proposed method achieves superior performance in different modalities.
基金supported by Earmarked Fund for China Agricultural Research System(grant number CARS-28)to G.W.and W.X.the National Natural Science Foundation of China(grant number 32172475)to W.X.
文摘Circular single-stranded DNA(ssDNA)viruses have been rarely found in fungi,and the evolutionary and ecological relationships among ssDNA viruses infecting fungi and other organisms remain unclear.In this study,a novel circular ssDNA virus,tentatively named Diaporthe sojae circular DNA virus 1(DsCDV1),was identified in the phytopathogenic fungus Diaporthe sojae isolated from pear trees.DsCDV1 has a monopartite genome(3185 nt in size)encapsidated in isometric virions(21-26 nm in diameter).The genome comprises seven putative open reading frames encoding a discrete replicase(Rep)split by an intergenic region,a putative capsid protein(CP),several proteins of unknown function(P1-P4),and a long intergenic region.Notably,the two split parts of DsCDV1 Rep share high identities with the Reps of Geminiviridae and Genomoviridae,respectively,indicating an evolutionary linkage with both families.Phylogenetic analysis based on Rep or CP sequences placed DsCDV1 in a unique cluster,supporting the establishment of a new family,tentatively named Gegemycoviridae,intermediate to both families.DsCDV1 significantly attenuates fungal growth and nearly erases fungal virulence when transfected into the host fungus.Remarkably,DsCDV1 can systematically infect tobacco and pear seedlings,providing broad-spectrum resistance to fungal diseases.Subcellular localization analysis revealed that DsCDV1 P3 is systematically localized in the plasmodesmata,while its expression in trans-complementation experiments could restore systematic infection of a movement-deficient plant virus,suggesting that P3 is a movement protein.DsCDV1 exhibits unique molecular and biological traits not observed in other ssDNA viruses,serving as a link between fungal and plant ssDNA viruses and presenting an evolutionary connection between ssDNA viruses and fungi.These findings contribute to expanding our understanding of ssDNA virus diversity and evolution,offering potential biocontrol applications for managing crucial plant diseases.