Recently,electronic skins and fl exible wearable devices have been developed for widespread applications in medical monitoring,artifi cial intelligence,human–machine interaction,and artifi cial prosthetics.Flexible p...Recently,electronic skins and fl exible wearable devices have been developed for widespread applications in medical monitoring,artifi cial intelligence,human–machine interaction,and artifi cial prosthetics.Flexible proximity sensors can accurately perceive external objects without contact,introducing a new way to achieve an ultrasensitive perception of objects.This article reviews the progress of fl exible capacitive proximity sensors,fl exible triboelectric proximity sensors,and fl exible gate-enhanced proximity sensors,focusing on their applications in the electronic skin fi eld.Herein,their working mechanism,materials,preparation methods,and research progress are discussed in detail.Finally,we summarize the future challenges in developing fl exible proximity sensors.展开更多
Achieving increasingly finely targeted drug delivery to organs,tissues,cells,and even to intracellular biomacromolecules is one of the core goals of nanomedicines.As the delivery destination is refined to cellular and...Achieving increasingly finely targeted drug delivery to organs,tissues,cells,and even to intracellular biomacromolecules is one of the core goals of nanomedicines.As the delivery destination is refined to cellular and subcellular targets,it is essential to explore the delivery of nanomedicines at the molecular level.However,due to the lack of technical methods,the molecular mechanism of the intracellular delivery of nanomedicines remains unclear to date.Here,we develop an enzyme-induced proximity labeling technology in nanoparticles(nano-EPL)for the real-time monitoring of proteins that interact with intracellular nanomedicines.Poly(lactic-co-glycolic acid)nanoparticles coupled with horseradish peroxidase(HRP)were fabricated as a model(HRP(+)-PNPs)to evaluate the molecular mechanism of nano delivery in macrophages.By adding the labeling probe biotin-phenol and the catalytic substrate H_(2)O_(2)at different time points in cellular delivery,nano-EPL technology was validated for the real-time in situ labeling of proteins interacting with nanoparticles.Nano-EPL achieves the dynamic molecular profiling of 740 proteins to map the intracellular delivery of HRP(+)-PNPs in macrophages over time.Based on dynamic clustering analysis of these proteins,we further discovered that different organelles,including endosomes,lysosomes,the endoplasmic reticulum,and the Golgi apparatus,are involved in delivery with distinct participation timelines.More importantly,the engagement of these organelles differentially affects the drug delivery efficiency,reflecting the spatial–temporal heterogeneity of nano delivery in cells.In summary,these findings highlight a significant methodological advance toward understanding the molecular mechanisms involved in the intracellular delivery of nanomedicines.展开更多
Two-dimensional(2D)magnet/superconductor heterostructures can promote the design of artificial materials for exploring 2D physics and device applications by exotic proximity effects.However,plagued by the low Curie te...Two-dimensional(2D)magnet/superconductor heterostructures can promote the design of artificial materials for exploring 2D physics and device applications by exotic proximity effects.However,plagued by the low Curie temperature and instability in air,it is hard to realize practical applications for the reported layered magnetic materials at present.In this paper,we developed a space-confined chemical vapor deposition method to synthesize ultrathin air-stable ε-Fe_(2)O_(3) nanosheets with Curie temperature above 350 K.The ε-Fe_(2)O_(3)/NbSe_(2) heterojunction was constructed to study the magnetic proximity effect on the superconductivity of the NbSe_(2) multilayer.The electrical transport results show that the subtle proximity effect can modulate the interfacial spin–orbit interaction while undegrading the superconducting critical parameters.Our work paves the way to construct 2D heterojunctions with ultrathin nonlayered materials and layered van der Waals(vdW)materials for exploring new physical phenomena.展开更多
In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relat...In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.展开更多
The interaction between a promoter and an active metal crucially impacts catalytic performance.Nowadays,the influence of promoter contents and species has been intensively considered.In this study,we investigate the e...The interaction between a promoter and an active metal crucially impacts catalytic performance.Nowadays,the influence of promoter contents and species has been intensively considered.In this study,we investigate the effect of the iron(Fe)-zinc(Zn)proximity of Fe-Zn bimetallic catalysts on CO_(2)hydrogenation performance.To eliminate the size effect,Fe_(2)O_(3)and ZnO nanoparticles with uniform size are first prepared by the thermal decomposition method.By changing the loading sequence or mixing method,a series of Fe-Zn bimetallic catalysts with different Fe-Zn distances are obtained.Combined with a series of characterization techniques and catalytic performances,Fe-Zn bimetallic proximity for compositions of Fe species is discussed.Furthermore,we observe that a smaller Fe-Zn distance inhibits the reduction and carburization of the Fe species and facilitates the oxidation of carbides.Appropriate proximity of Fe and Zn(i.e.,Fe_1Zn_(1)-imp and Fe_(1)Zn_(1)-mix samples)results in a suitable ratio of the Fe_5C_(2)and Fe_(3)O_(4)phases,simultaneously promoting the reverse water-gas shift and Fischer-Tropsch synthesis reactions.This study provides insight into the proximity effect of bimetallic catalysts on CO_(2)hydrogenation performance.展开更多
The interrupted-sampling repeater jamming(ISRJ)can cause false targets to the radio-frequency proximity sensors(RFPSs),resulting in a serious decline in the target detection capability of the RFPS.This article propose...The interrupted-sampling repeater jamming(ISRJ)can cause false targets to the radio-frequency proximity sensors(RFPSs),resulting in a serious decline in the target detection capability of the RFPS.This article proposes a recognition method for RFPSs to identify the false targets caused by ISRJ.The proposed method is realized by assigning a unique identity(ID)to each RFPS,and each ID is a periodically and chaotically encrypted in every pulse period.The processing technique of the received signal is divided into ranging and ID decryption.In the ranging part,a high-resolution range profile(HRRP)can be obtained by performing pulse compression with the binary chaotic sequences.To suppress the noise,the singular value decomposition(SVD)is applied in the preprocessing.Regarding ID decryption,targets and ISRJ can be recognized through the encryption and decryption processes,which are controlled by random keys.An adaptability analysis conducted in terms of the peak-to-side lobe ratio(PSLR)and bit error rate(BER)indicates that the proposed method performs well within a 70-k Hz Doppler shift.A simulation and experimental results show that the proposed method achieves extremely stable target and ISRJ recognition accuracies at different signal-to-noise ratios(SNRs)and jamming-to-signal ratios(JSRs).展开更多
The study of the neuron has always been a fundamental aspect when it came to studying mental illnesses such as autism and depression. The protein protocadherin-9 (PCDH9) is an important transmembrane protein in the de...The study of the neuron has always been a fundamental aspect when it came to studying mental illnesses such as autism and depression. The protein protocadherin-9 (PCDH9) is an important transmembrane protein in the development of the neuron synapse. Hence, research on its protein interactome is key to understanding its functionality and specific properties. A newly discovered biotin ligase, TurboID, is a proximity labeler that is designed to be able to label and observe transmembrane proteins, something that previous methods struggled with. The TurboID method is verified in HEK293T cells and primary cultured mouse cortical neurons. Results have proven the validity of the TurboID method in observing PCDH9-interacting proteins.展开更多
Transport infrastructure plays an important role in shaping the configuration of spatial socio-economic structures and influences regional accessibility. This paper defines transport dominance from three aspects: qua...Transport infrastructure plays an important role in shaping the configuration of spatial socio-economic structures and influences regional accessibility. This paper defines transport dominance from three aspects: quafity, quantity, and advantage, measured by density, proximity, and accessibility indices. County is the basic unit for analysis. The results reveal: (1) Transport dominance statistically follows a partial normal distribution. A very few counties, 1.4% of the total, have extremely high transport dominance which strongly supports the socio-economic development in these areas. In contrast, one eighth of all counties have poor transport dominance which impedes local socio-economic development to some extent. The remaining areas, about 70% of the counties, have median transport dominance. (2) Transport dominance is spatially unevenly distributed, with values decreasing gradually from the coastal area to the inland area. Areas in the first-highest level of transport dominance are mainly concentrated in the Yangtze River Delta, the Greater Beijing area, and the Pearl River Delta. Areas in the second-highest level are focused in Chengdu, Chongqing, and Wuhan metropolitan areas. Provincial capitals and a few other counties belong to the third-highest level.展开更多
The rails of electromagnetic railgun can be ablated by the temperature rise due to current concentration.The current distributions on the rails and armature are not only affected by the skin effect,but also influenced...The rails of electromagnetic railgun can be ablated by the temperature rise due to current concentration.The current distributions on the rails and armature are not only affected by the skin effect,but also influenced by the proximity effect which is rarely mentioned.This paper illustrated the difference between skin effect and proximity effect,and the influencing factors of proximity effect were investigated.Results show that the current is concentrated on the surface around rails due to the skin effect,and the proximity effect exacerbates the current density on the inner surfaces of rails.Decrease in distance from rails enhances the proximity effect,but has nothing to do with the skin effect,which also augments the rail resistance,resulting in temperature rise.It can explain the reason why the ablation is often detected in the small caliber railgun.Research results in this paper can provide support for design and optimization of electromagnetic railgun.展开更多
Topographic feature points and lines are the framework of topography,and their spatial distance relationship is an breakthrough in the study of topographical geometry,internal structure and development level.Proximity...Topographic feature points and lines are the framework of topography,and their spatial distance relationship is an breakthrough in the study of topographical geometry,internal structure and development level.Proximity distance(PD)is an indicator to describe the distance between the gully source point(GSP)and the watershed boundary.In the upstream catchment area,PDs can be expressed by the streamline proximity distance(SPD),as well as by the horizontal proximity distance(HPD)and the vertical proximity distance(VPD)in the horizontal and vertical dimensions,respectively.The series of indicators(e.g.,SPD,HPD and VPD)are important for quantifying the geomorphological development process of a loess basin because of the headward erosion of loess gullies.In this study,the digital elevation model data with 5 m resolution and a digital topographic analysis method are used for the statistical analyses of the SPD,VPD and HPD in 50 sample areas of 6 geomorphic types in the Loess Plateau of northern Shaanxi.The spatial characteristics and the influencing factors are also analysed.Results show that:1)Central tendencies for the HPDs and the VPDs for the whole study area and the six typical loess landforms are evident.2)Spatial patterns of the HPDs and the VPDs exhibit evident trends and zonal distributions over the whole study area.3)The HPDs have a strong positive correlation with gully density(GD)and hypsometric integral.The VPDs also correlates with GD to an extent.Vegetation cover,mean annual precipitation and loess thickness have stronger effects on the VPD than on the HPD.展开更多
High resolution Fresnel zone plates for nanoscale three-dimensional imaging of materials by both soft and hard x-rays are increasingly needed by the broad applications in nanoscience and nanotechnology.When the outmos...High resolution Fresnel zone plates for nanoscale three-dimensional imaging of materials by both soft and hard x-rays are increasingly needed by the broad applications in nanoscience and nanotechnology.When the outmost zone-width is shrinking down to 50 nm or even below,patterning the zone plates with high aspect ratio by electron beam lithography still remains a challenge because of the proximity effect.The uneven charge distribution in the exposed resist is still frequently observed even after standard proximity effect correction(PEC),because of the large variety in the line width.This work develops a new strategy,nicknamed as local proximity effect correction(LPEC),efficiently modifying the deposited energy over the whole zone plate on the top of proximity effect correction.By this way,50 nm zone plates with the aspect ratio from 4:1 up to 15:1 and the duty cycle close to 0.5 have been fabricated.Their imaging capability in soft(1.3 keV)and hard(9 keV)x-ray,respectively,has been demonstrated in Shanghai Synchrotron Radiation Facility(SSRF)with the resolution of 50 nm.The local proximity effect correction developed in this work should also be generally significant for the generation of zone plates with high resolutions beyond 50 nm.展开更多
Due to environmental damage and natural resource scarcity,the promotion of industrial green development to spur the industrial economy is of concern to many countries.We construct a theoretical framework of technologi...Due to environmental damage and natural resource scarcity,the promotion of industrial green development to spur the industrial economy is of concern to many countries.We construct a theoretical framework of technological innovation,market proximity,and industrial green development and subsequently test it empirically.First,the results reveal that technological innovation is beneficial to industrial green development;technological innovation has a positive impact on industrial green development in adjacent regions through technology spillover,but human capital spillover has the opposite effect;the international market can effectively promote industrial green development,but the domestic market does the opposite.Second,the interaction between technology spillover,human capital spillover,and domestic and international markets is beneficial to industrial green development.However,the interaction between domestic and international markets imposes an inhibitive effect on industrial green development.Based on the findings,we make recommendations to improve the level of industrial green development.展开更多
To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test ...To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.展开更多
In recent years, artificial intelligence and automotive industry have developed rapidly, and autonomous driving has gradually become the focus of the industry. In road networks, the problem of proximity detection refe...In recent years, artificial intelligence and automotive industry have developed rapidly, and autonomous driving has gradually become the focus of the industry. In road networks, the problem of proximity detection refers to detecting whether two moving objects are close to each other or not in real time. However, the battery life and computing capability of mobile devices are limited in the actual scene,which results in high latency and energy consumption. Therefore, it is a tough problem to determine the proximity relationship between mobile users with low latency and energy consumption. In this article, we aim at finding a tradeoff between latency and energy consumption. We formalize the computation offloading problem base on mobile edge computing(MEC)into a constrained multiobjective optimization problem(CMOP) and utilize NSGA-II to solve it. The simulation results demonstrate that NSGA-II can find the Pareto set, which reduces the latency and energy consumption effectively. In addition, a large number of solutions provided by the Pareto set give us more choices of the offloading decision according to the actual situation.展开更多
We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally an...We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally and was affected by temperature and rainfall.Preferred proximity association was not distributed randomly among individuals.Kinship was one explanation for the social structure,as offspring preferred to maintain close proximity with their mothers.The proximity of infants to mothers decreased with age,and independent offspring had lower proximity to mothers than dependent ones.We found that the adult male had different proximity relationships with two different adult females.The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group.Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences.Temperature influenced group proximity association,with individual proximity increasing in the cold months and decreasing in the hot months.Group proximity decreased in months with higher anthropogenic disturbance.展开更多
Moral imagination is the ability that can help individuals overcome constraints of organizational mental models to develop fresh frameworks and to make ethical decisions on the basis of those frameworks.This study aim...Moral imagination is the ability that can help individuals overcome constraints of organizational mental models to develop fresh frameworks and to make ethical decisions on the basis of those frameworks.This study aimed to explore the moderated mediator role of organizational commitment between ethical leadership and moral imagination.Data of 281 employees were collected,and results showed that when the victim of a certain ethical issue is their own company,organizational commitment fully mediated the effect of ethical leadership on moral imagination;however,when the victim is other company,ethical leadership and organizational commitment hadn't any effect on moral imagination.Those results showed the process that ethical leadership uses to influence moral imagination is not a social learning process but a social exchange process.展开更多
Topological insulators (Tls) are bulk insulators that possess robust helical conducting states along their interfaces with conventional insulators. A tremendous research effort has recently been devoted to TI-based ...Topological insulators (Tls) are bulk insulators that possess robust helical conducting states along their interfaces with conventional insulators. A tremendous research effort has recently been devoted to TI-based heterostructures, in which con- ventional proximity effects give rise to a series of exotic physical phenomena. This paper reviews our recent studies on the potential existence of topological proximity effects at the interface between a topological insulator and a normal insu- lator or other topologically trivial systems. Using first-principles approaches, we have realized the tunability of the vertical location of the topological helical state via intriguing dual-proximity effects. To further elucidate the control parameters of this effect, we have used the graphene-based heterostructures as prototypical systems to reveal a more complete phase diagram. On the application side of the topological helical states, we have presented a catalysis example, where the topo- logical helical state plays an essential role in facilitating surface reactions by serving as an effective electron bath, These discoveries lay the foundation for accurate manipulation of the real space properties of the topological helical state in TI- based heterostructures and pave the way for realization of the salient functionality of topological insulators in future device applications.展开更多
基金supported by the National Key R&D Program of China(Nos.2022 YFF 1202700 and 2022YFB3203500)National Natural Science Foundation of China(Nos.62225403,62375046,51973024,an d U19A2091)+2 种基金“111”Project(No.B13013)Natur al Sci ence Foundation of Jilin Pro vin ce(No.20230101113JC)the Funding from Jilin Pr ovince(No.20220502002GH).
文摘Recently,electronic skins and fl exible wearable devices have been developed for widespread applications in medical monitoring,artifi cial intelligence,human–machine interaction,and artifi cial prosthetics.Flexible proximity sensors can accurately perceive external objects without contact,introducing a new way to achieve an ultrasensitive perception of objects.This article reviews the progress of fl exible capacitive proximity sensors,fl exible triboelectric proximity sensors,and fl exible gate-enhanced proximity sensors,focusing on their applications in the electronic skin fi eld.Herein,their working mechanism,materials,preparation methods,and research progress are discussed in detail.Finally,we summarize the future challenges in developing fl exible proximity sensors.
基金supported by Natural Science Foundation of Beijing Municipality(L212013)National Key Research and Development Program of China(No.2022YFA1206104)+2 种基金AI+Health Collaborative Innovation Cultivation Project(Z211100003521002)National Natural Science Foundation of China(81971718,82073786,81872809,U20A20412,81821004)Beijing Natural Science Foundation(7222020).
文摘Achieving increasingly finely targeted drug delivery to organs,tissues,cells,and even to intracellular biomacromolecules is one of the core goals of nanomedicines.As the delivery destination is refined to cellular and subcellular targets,it is essential to explore the delivery of nanomedicines at the molecular level.However,due to the lack of technical methods,the molecular mechanism of the intracellular delivery of nanomedicines remains unclear to date.Here,we develop an enzyme-induced proximity labeling technology in nanoparticles(nano-EPL)for the real-time monitoring of proteins that interact with intracellular nanomedicines.Poly(lactic-co-glycolic acid)nanoparticles coupled with horseradish peroxidase(HRP)were fabricated as a model(HRP(+)-PNPs)to evaluate the molecular mechanism of nano delivery in macrophages.By adding the labeling probe biotin-phenol and the catalytic substrate H_(2)O_(2)at different time points in cellular delivery,nano-EPL technology was validated for the real-time in situ labeling of proteins interacting with nanoparticles.Nano-EPL achieves the dynamic molecular profiling of 740 proteins to map the intracellular delivery of HRP(+)-PNPs in macrophages over time.Based on dynamic clustering analysis of these proteins,we further discovered that different organelles,including endosomes,lysosomes,the endoplasmic reticulum,and the Golgi apparatus,are involved in delivery with distinct participation timelines.More importantly,the engagement of these organelles differentially affects the drug delivery efficiency,reflecting the spatial–temporal heterogeneity of nano delivery in cells.In summary,these findings highlight a significant methodological advance toward understanding the molecular mechanisms involved in the intracellular delivery of nanomedicines.
基金The work is supported by the National Key Research and Development Program of China(Grant No.2022YFA1204104)the National Natural Science Foundation of China(Grant No.61888102)the Chinese Academy of Sciences(Grant Nos.ZDBS-SSW-WHC001 and XDB33030100).
文摘Two-dimensional(2D)magnet/superconductor heterostructures can promote the design of artificial materials for exploring 2D physics and device applications by exotic proximity effects.However,plagued by the low Curie temperature and instability in air,it is hard to realize practical applications for the reported layered magnetic materials at present.In this paper,we developed a space-confined chemical vapor deposition method to synthesize ultrathin air-stable ε-Fe_(2)O_(3) nanosheets with Curie temperature above 350 K.The ε-Fe_(2)O_(3)/NbSe_(2) heterojunction was constructed to study the magnetic proximity effect on the superconductivity of the NbSe_(2) multilayer.The electrical transport results show that the subtle proximity effect can modulate the interfacial spin–orbit interaction while undegrading the superconducting critical parameters.Our work paves the way to construct 2D heterojunctions with ultrathin nonlayered materials and layered van der Waals(vdW)materials for exploring new physical phenomena.
文摘In this paper,the mission and the thermal environment of the Solar Close Observations and Proximity Experiments(SCOPE)spacecraft are analyzed,and an advanced thermal management system(ATMS)is designed for it.The relationship and functions of the integrated database,the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon.For the complex thermal field regulation system and extreme space thermal environment,a modular simulation and thermal field planning method are proposed,and the feasibility of the planning algorithm is verified by numerical simulation.A solar array liquid cooling system is developed,and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion.The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.
基金supported by National Natural Science Foundation of China(Nos.22108200,21938008 and 22121004)Natural Science Foundation of Zhejiang Province(LQ22B060013)the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘The interaction between a promoter and an active metal crucially impacts catalytic performance.Nowadays,the influence of promoter contents and species has been intensively considered.In this study,we investigate the effect of the iron(Fe)-zinc(Zn)proximity of Fe-Zn bimetallic catalysts on CO_(2)hydrogenation performance.To eliminate the size effect,Fe_(2)O_(3)and ZnO nanoparticles with uniform size are first prepared by the thermal decomposition method.By changing the loading sequence or mixing method,a series of Fe-Zn bimetallic catalysts with different Fe-Zn distances are obtained.Combined with a series of characterization techniques and catalytic performances,Fe-Zn bimetallic proximity for compositions of Fe species is discussed.Furthermore,we observe that a smaller Fe-Zn distance inhibits the reduction and carburization of the Fe species and facilitates the oxidation of carbides.Appropriate proximity of Fe and Zn(i.e.,Fe_1Zn_(1)-imp and Fe_(1)Zn_(1)-mix samples)results in a suitable ratio of the Fe_5C_(2)and Fe_(3)O_(4)phases,simultaneously promoting the reverse water-gas shift and Fischer-Tropsch synthesis reactions.This study provides insight into the proximity effect of bimetallic catalysts on CO_(2)hydrogenation performance.
基金supported by the National Natural Science Foundation of China(Grant No.61973037)and(Grant No.61871414)Postdoctoral Fundation of China(Grant No.2022M720419)。
文摘The interrupted-sampling repeater jamming(ISRJ)can cause false targets to the radio-frequency proximity sensors(RFPSs),resulting in a serious decline in the target detection capability of the RFPS.This article proposes a recognition method for RFPSs to identify the false targets caused by ISRJ.The proposed method is realized by assigning a unique identity(ID)to each RFPS,and each ID is a periodically and chaotically encrypted in every pulse period.The processing technique of the received signal is divided into ranging and ID decryption.In the ranging part,a high-resolution range profile(HRRP)can be obtained by performing pulse compression with the binary chaotic sequences.To suppress the noise,the singular value decomposition(SVD)is applied in the preprocessing.Regarding ID decryption,targets and ISRJ can be recognized through the encryption and decryption processes,which are controlled by random keys.An adaptability analysis conducted in terms of the peak-to-side lobe ratio(PSLR)and bit error rate(BER)indicates that the proposed method performs well within a 70-k Hz Doppler shift.A simulation and experimental results show that the proposed method achieves extremely stable target and ISRJ recognition accuracies at different signal-to-noise ratios(SNRs)and jamming-to-signal ratios(JSRs).
文摘The study of the neuron has always been a fundamental aspect when it came to studying mental illnesses such as autism and depression. The protein protocadherin-9 (PCDH9) is an important transmembrane protein in the development of the neuron synapse. Hence, research on its protein interactome is key to understanding its functionality and specific properties. A newly discovered biotin ligase, TurboID, is a proximity labeler that is designed to be able to label and observe transmembrane proteins, something that previous methods struggled with. The TurboID method is verified in HEK293T cells and primary cultured mouse cortical neurons. Results have proven the validity of the TurboID method in observing PCDH9-interacting proteins.
基金National Natural Science Foundation of China, No.40635026 40701045 Knowledge Innovation Program of the Chinese Academy of Sciences, No.KZCX2-YW-Q 10-4
文摘Transport infrastructure plays an important role in shaping the configuration of spatial socio-economic structures and influences regional accessibility. This paper defines transport dominance from three aspects: quafity, quantity, and advantage, measured by density, proximity, and accessibility indices. County is the basic unit for analysis. The results reveal: (1) Transport dominance statistically follows a partial normal distribution. A very few counties, 1.4% of the total, have extremely high transport dominance which strongly supports the socio-economic development in these areas. In contrast, one eighth of all counties have poor transport dominance which impedes local socio-economic development to some extent. The remaining areas, about 70% of the counties, have median transport dominance. (2) Transport dominance is spatially unevenly distributed, with values decreasing gradually from the coastal area to the inland area. Areas in the first-highest level of transport dominance are mainly concentrated in the Yangtze River Delta, the Greater Beijing area, and the Pearl River Delta. Areas in the second-highest level are focused in Chengdu, Chongqing, and Wuhan metropolitan areas. Provincial capitals and a few other counties belong to the third-highest level.
文摘The rails of electromagnetic railgun can be ablated by the temperature rise due to current concentration.The current distributions on the rails and armature are not only affected by the skin effect,but also influenced by the proximity effect which is rarely mentioned.This paper illustrated the difference between skin effect and proximity effect,and the influencing factors of proximity effect were investigated.Results show that the current is concentrated on the surface around rails due to the skin effect,and the proximity effect exacerbates the current density on the inner surfaces of rails.Decrease in distance from rails enhances the proximity effect,but has nothing to do with the skin effect,which also augments the rail resistance,resulting in temperature rise.It can explain the reason why the ablation is often detected in the small caliber railgun.Research results in this paper can provide support for design and optimization of electromagnetic railgun.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41871288, 41930102 and 41602182)the Fundamental Research Funds for the Central Universities (Grant No. 2018CSLZ002)
文摘Topographic feature points and lines are the framework of topography,and their spatial distance relationship is an breakthrough in the study of topographical geometry,internal structure and development level.Proximity distance(PD)is an indicator to describe the distance between the gully source point(GSP)and the watershed boundary.In the upstream catchment area,PDs can be expressed by the streamline proximity distance(SPD),as well as by the horizontal proximity distance(HPD)and the vertical proximity distance(VPD)in the horizontal and vertical dimensions,respectively.The series of indicators(e.g.,SPD,HPD and VPD)are important for quantifying the geomorphological development process of a loess basin because of the headward erosion of loess gullies.In this study,the digital elevation model data with 5 m resolution and a digital topographic analysis method are used for the statistical analyses of the SPD,VPD and HPD in 50 sample areas of 6 geomorphic types in the Loess Plateau of northern Shaanxi.The spatial characteristics and the influencing factors are also analysed.Results show that:1)Central tendencies for the HPDs and the VPDs for the whole study area and the six typical loess landforms are evident.2)Spatial patterns of the HPDs and the VPDs exhibit evident trends and zonal distributions over the whole study area.3)The HPDs have a strong positive correlation with gully density(GD)and hypsometric integral.The VPDs also correlates with GD to an extent.Vegetation cover,mean annual precipitation and loess thickness have stronger effects on the VPD than on the HPD.
基金Project supported by the National Natural Science Foundation of China(Grant No.U1732104)China Postdoctoral Science Foundation(Grant No.2017M611443)Shanghai STCSM2019-11-20 Grant,China(Grant No.19142202700)。
文摘High resolution Fresnel zone plates for nanoscale three-dimensional imaging of materials by both soft and hard x-rays are increasingly needed by the broad applications in nanoscience and nanotechnology.When the outmost zone-width is shrinking down to 50 nm or even below,patterning the zone plates with high aspect ratio by electron beam lithography still remains a challenge because of the proximity effect.The uneven charge distribution in the exposed resist is still frequently observed even after standard proximity effect correction(PEC),because of the large variety in the line width.This work develops a new strategy,nicknamed as local proximity effect correction(LPEC),efficiently modifying the deposited energy over the whole zone plate on the top of proximity effect correction.By this way,50 nm zone plates with the aspect ratio from 4:1 up to 15:1 and the duty cycle close to 0.5 have been fabricated.Their imaging capability in soft(1.3 keV)and hard(9 keV)x-ray,respectively,has been demonstrated in Shanghai Synchrotron Radiation Facility(SSRF)with the resolution of 50 nm.The local proximity effect correction developed in this work should also be generally significant for the generation of zone plates with high resolutions beyond 50 nm.
基金This paper is supported by the key program of National Social Science Foundation of China“Research on the Theoretical Basis and Index System of Building a Modern Economic System in the New Era”[Grant number:18XKS009]the Foundation of Sichuan Provincial Soft Science Research“Research on the Way of Improving Quality and Increasing Efficiency of Sichuan Science and Technology Business Incubator in New Era”[Grant number:2020JDR0110].
文摘Due to environmental damage and natural resource scarcity,the promotion of industrial green development to spur the industrial economy is of concern to many countries.We construct a theoretical framework of technological innovation,market proximity,and industrial green development and subsequently test it empirically.First,the results reveal that technological innovation is beneficial to industrial green development;technological innovation has a positive impact on industrial green development in adjacent regions through technology spillover,but human capital spillover has the opposite effect;the international market can effectively promote industrial green development,but the domestic market does the opposite.Second,the interaction between technology spillover,human capital spillover,and domestic and international markets is beneficial to industrial green development.However,the interaction between domestic and international markets imposes an inhibitive effect on industrial green development.Based on the findings,we make recommendations to improve the level of industrial green development.
基金supported by Project of the National Natural Science Foundation of China (No.62073256, 61773305)the Key Science and Technology Program of Shaanxi Province (No.2020GY-125)Xi’an Science and Technology Innovation talent service enterprise project (No.2020KJRC0041)。
文摘To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.
基金supported in part by the National Natural Science Foundation of China (Grant No. 61901052)in part by the 111 project (Grant No. B17007)in part by the Director Funds of Beijing Key Laboratory of Network System Architecture and Convergence (Grant No. 2017BKL-NSACZJ-02)。
文摘In recent years, artificial intelligence and automotive industry have developed rapidly, and autonomous driving has gradually become the focus of the industry. In road networks, the problem of proximity detection refers to detecting whether two moving objects are close to each other or not in real time. However, the battery life and computing capability of mobile devices are limited in the actual scene,which results in high latency and energy consumption. Therefore, it is a tough problem to determine the proximity relationship between mobile users with low latency and energy consumption. In this article, we aim at finding a tradeoff between latency and energy consumption. We formalize the computation offloading problem base on mobile edge computing(MEC)into a constrained multiobjective optimization problem(CMOP) and utilize NSGA-II to solve it. The simulation results demonstrate that NSGA-II can find the Pareto set, which reduces the latency and energy consumption effectively. In addition, a large number of solutions provided by the Pareto set give us more choices of the offloading decision according to the actual situation.
基金supported by the Yunnan Provincial Science and Technology Infrastructure Program(2011FB105)the National Natural Science Foundation of China(31070349).
文摘We investigated the structure and seasonality of the proximity network in a group of polygynous western black crested gibbons(Nomascus concolor)using social network analysis.The spatial proximity changed seasonally and was affected by temperature and rainfall.Preferred proximity association was not distributed randomly among individuals.Kinship was one explanation for the social structure,as offspring preferred to maintain close proximity with their mothers.The proximity of infants to mothers decreased with age,and independent offspring had lower proximity to mothers than dependent ones.We found that the adult male had different proximity relationships with two different adult females.The frequency of proximity between the male and the infant-carrying female was significantly higher than that between the male and the female who had immigrated carrying one offspring of uncertain paternity into the group.Infanticide avoidance and/or predation protection for dependent infants might explain the proximity relationship differences.Temperature influenced group proximity association,with individual proximity increasing in the cold months and decreasing in the hot months.Group proximity decreased in months with higher anthropogenic disturbance.
基金supported by a grant from the Chinese National Scientific Foundation(71002112,71562017)
文摘Moral imagination is the ability that can help individuals overcome constraints of organizational mental models to develop fresh frameworks and to make ethical decisions on the basis of those frameworks.This study aimed to explore the moderated mediator role of organizational commitment between ethical leadership and moral imagination.Data of 281 employees were collected,and results showed that when the victim of a certain ethical issue is their own company,organizational commitment fully mediated the effect of ethical leadership on moral imagination;however,when the victim is other company,ethical leadership and organizational commitment hadn't any effect on moral imagination.Those results showed the process that ethical leadership uses to influence moral imagination is not a social learning process but a social exchange process.
基金supported by the National Natural Science Foundation of China (Grant Nos. 91021019, 51074151, and 11034006)the National Basic Research Program of China (Grant Nos. 2010CB923401 and 2011CB921801)+2 种基金USDOE (Grant No. DE-FG03-02ER45958)US National Science Foundation (Grant No. 0906025)the BES Program of US Department of Energy (Grant No. ER45958)
文摘Topological insulators (Tls) are bulk insulators that possess robust helical conducting states along their interfaces with conventional insulators. A tremendous research effort has recently been devoted to TI-based heterostructures, in which con- ventional proximity effects give rise to a series of exotic physical phenomena. This paper reviews our recent studies on the potential existence of topological proximity effects at the interface between a topological insulator and a normal insu- lator or other topologically trivial systems. Using first-principles approaches, we have realized the tunability of the vertical location of the topological helical state via intriguing dual-proximity effects. To further elucidate the control parameters of this effect, we have used the graphene-based heterostructures as prototypical systems to reveal a more complete phase diagram. On the application side of the topological helical states, we have presented a catalysis example, where the topo- logical helical state plays an essential role in facilitating surface reactions by serving as an effective electron bath, These discoveries lay the foundation for accurate manipulation of the real space properties of the topological helical state in TI- based heterostructures and pave the way for realization of the salient functionality of topological insulators in future device applications.