期刊文献+
共找到256篇文章
< 1 2 13 >
每页显示 20 50 100
Independent dual-band bound states in the continuum based on terahertz all-dielectric metasurfaces
1
作者 WANG Yu LIU Yang +5 位作者 HAO Xiao-yu ZHENG Si-yu LIU Meng ZHANG Yu-ping ZHAN Yi ZHANG Hui-yun 《中国光学(中英文)》 北大核心 2025年第5期1230-1242,共13页
Compared to traditional single-frequency bound states in the continuum(BIC),dual-band BIC of-fers higher degrees of freedom and functionality.Moveover,implementing independent control of dual-band BICs can further enh... Compared to traditional single-frequency bound states in the continuum(BIC),dual-band BIC of-fers higher degrees of freedom and functionality.Moveover,implementing independent control of dual-band BICs can further enhance their advantages and maximize their performance.This study presents a design for a dielectric metasurface that achieves dual-band BICs in the terahertz(THz)range.By adjusting two asym-metry parameters of the structure,independent control of the two symmetry-protected BICs is achieved.Fur-thermore,by varying the shape of the silicon holes,the design's robustness to geometric variations is demon-strated.Finally,the test results show that the figures of merit(FOMs)for both BICs reach 109.This work provides a new approach for realizing and tuning dual-frequency BICs,offering expanded possibilities for applications in multimode lasers,nonlinear optics,multi-channel filtering,and optical sensing. 展开更多
关键词 dual-band bound states in the continuum metasurface terahertz sensing symmetry protection
在线阅读 下载PDF
Fukui Functions for the Temporary Anion Resonance States of Be^-, Mg^-, and Ca^- 被引量:1
2
作者 MORRISON Robert C. 《物理化学学报》 SCIE CAS CSCD 北大核心 2018年第3期263-269,共7页
In this work,the Fukui functions of the two ~2P resonance states of Be,a ~2P resonance state of Mg~–,and a ~2D resonance state of Ca~– have been determined.The trajectories of these resonance states,in conjunction w... In this work,the Fukui functions of the two ~2P resonance states of Be,a ~2P resonance state of Mg~–,and a ~2D resonance state of Ca~– have been determined.The trajectories of these resonance states,in conjunction with the complex rotation of the Hamiltonian,were used to determine their wave functions.The electron densities,Fukui functions,and values of the hyper-radius<r^2>were computed from these wave functions.The Fukui functions have negative regions in the valence shell in addition to the inner shell regions,indicating screening effects of the outer temporary electron.Selected configuration interactions with up to quadruple excitations were used along the trajectories and for computing the final wave function.Based on this data,the densities,Fukui functions,and<r^2>were calculated. 展开更多
关键词 Fukui functions Density functional theory Temporary anion states Resonance states Complex rotation
在线阅读 下载PDF
Observability and estimability of passive radar with unknown illuminator states using different observations 被引量:2
3
作者 JING Tong TIAN Wei +1 位作者 HUANG Gaoming PENG Huafu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2020年第6期1193-1205,共13页
Most existing studies about passive radar systems are based on the already known illuminator of opportunity(IO)states.However,in practice,the receiver generally has little knowledge about the IO states.Little research... Most existing studies about passive radar systems are based on the already known illuminator of opportunity(IO)states.However,in practice,the receiver generally has little knowledge about the IO states.Little research has studied this problem.This paper analyzes the observability and estimability for passive radar systems with unknown IO states under three typical scenarios.Besides,the directions of high and low estimability with respect to various states are given.Moreover,two types of observations are taken into account.The effects of different observations on both observability and estimability are well analyzed.For the observability test,linear and nonlinear methods are considered,which proves that both tests are applicable to the system.Numerical simulations confirm the correctness of the theoretical analysis. 展开更多
关键词 passive radar passive coherent location(PCL) OBSERVABILITY ESTIMABILITY unknown illuminator states
在线阅读 下载PDF
The Future of Disability Policy and Vocational Rehabilitation in the United States 被引量:2
4
作者 Henry D. Wong 《中国康复理论与实践》 CSCD 2006年第9期742-744,共3页
This article focuses on current and future disability public policy having potential implications for the Rehabilitation Act and vocational rehabilitation services in the United States. It explores several models of d... This article focuses on current and future disability public policy having potential implications for the Rehabilitation Act and vocational rehabilitation services in the United States. It explores several models of disability reflected in public policy, important historical legislation, and the relationship of the Workforce Investment Act (WIA) to the Rehabilitation Act. Competing issues and conflicts between the WIA and the state vocational rehabilitation agencies are discussed. A framework for analyzing disability policy is identified to project the future of disability policy, as well as, how these issues and conflicts may impact the survival of the rehabilitation profession. 展开更多
关键词 DISABILITY vocational rehabilitation United states
在线阅读 下载PDF
Fault detection based on H_∞ states observer for networked control systems 被引量:1
5
作者 Zhu Zhangqing Jiao Xiaocheng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期379-387,共9页
The influence of random short time-delay to networked control systems (NCS) is changed into an unknown bounded uncertain part. Without changing the structure of the system, an Hoo states observer is designed for NCS... The influence of random short time-delay to networked control systems (NCS) is changed into an unknown bounded uncertain part. Without changing the structure of the system, an Hoo states observer is designed for NCS with short time-delay. Based on the designed states observer, a robust fault detection approach is proposed for NCS. In addition, an optimization method for the selection of the detection threshold is introduced for better tradeoff between the robustness and the sensitivity. Finally, some simulation results demonstrate that the presented states observer is robust and the fault detection for NCS is effective. 展开更多
关键词 networked control systems fault detection states observers TIME-DELAYS ROBUSTNESS
在线阅读 下载PDF
TERM ENERGIES FOR THE AUTOIONIZING STATES OF THE LITHIUM ATOM 被引量:1
6
作者 Qu Lianhua Li BaiwenLaboratory of Magnetic Resonance and Atomic and Molecular Physics, WuhanInstitute of Physics, Chinese Academy of Science Wuhan 430071 《原子与分子物理学报》 CAS CSCD 北大核心 1998年第S1期33-34,共2页
1INTRODUCTIONRecently,afulcorepluscorrelation(FCPC)methodhasbeendevelopedbyChung[1]forsystemswhosecorewavefu... 1INTRODUCTIONRecently,afulcorepluscorrelation(FCPC)methodhasbeendevelopedbyChung[1]forsystemswhosecorewavefunctionsarenotstro... 展开更多
关键词 Autoionizing states RELATIVISTIC effects
在线阅读 下载PDF
基于Smolin states量子网络安全线路评估
7
作者 马鸿洋 王淑梅 《计算机工程与应用》 CSCD 北大核心 2009年第14期111-112,144,共3页
提出在由4个节点组成的量子网络中,基于Smolin state的量子网络安全线路评估传输协议。在量子网络中,有一个主节点、三个从节点,共享Smolin state态,随机的发送编码序列,利用测量结果的联合计算,来保证协议的安全性。理论分析证明,该协... 提出在由4个节点组成的量子网络中,基于Smolin state的量子网络安全线路评估传输协议。在量子网络中,有一个主节点、三个从节点,共享Smolin state态,随机的发送编码序列,利用测量结果的联合计算,来保证协议的安全性。理论分析证明,该协议对于三个窃听者、两个窃听者、一个窃听者都具有很高的安全性。如果存在窃听者存在,必然发现,从而保证了量子网络线路的安全性。 展开更多
关键词 量子网络 安全线路评估 身份认证 Smolin state态
在线阅读 下载PDF
Adding Transitions of Undefined States to State Transition Tables for Testability Enhancement
8
作者 Hiroyuki Yotsuyanagi, Masaki Hashizume, Takeomi Tamesada Dept. of Electrical and Electronic Engineering, The Univ. of Tokushima 2-1 Minami-Josanjima, 《湖南大学学报(自然科学版)》 EI CAS CSCD 2000年第S2期112-118,共7页
In this paper we propose procedures to enhance testability by adding transitions of undefined states to state transition tables. In these procedures, transitions about undefined states, which are not described in stat... In this paper we propose procedures to enhance testability by adding transitions of undefined states to state transition tables. In these procedures, transitions about undefined states, which are not described in state transition tables but exist in a synthesized gate level circuit, are added to a state transition table. Experimental results for MCNC benchmarks are shown. 展开更多
关键词 test generation undefined states state TRANSITION TABLES procedu
在线阅读 下载PDF
Two-dimensional linear connected-k system with trinary states and its reliability
9
作者 Xian Zhao Wei Zhao Weijuan Xie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第5期866-870,共5页
Existing studies about two-dimensional consecutivek-out-of-n: F system is dealt with two states (either component or system): working or failure. A new model for two-dimensional linear consecutive-k-out-of-n: F s... Existing studies about two-dimensional consecutivek-out-of-n: F system is dealt with two states (either component or system): working or failure. A new model for two-dimensional linear consecutive-k-out-of-n: F system is proposed, in which the components and systems can be at any of the three states: full working, derating working, and failure. Furthermore, two engineer- ing concrete instances of the new system are given. By using the finite Markov chain imbedding approach, the system reliability is presented in a unified formula with the product of matrices for the case of independent and identically distributed component states which can be extended to the independent but non-identical case easily. Finally, an example is given to illustrate the effectiveness of the above approach and tractability of various problems. 展开更多
关键词 RELIABILITY two-dimensional systems trinary states
在线阅读 下载PDF
The Algorithms for Achieving Global States and Self-Stabilization for Communication Protocols
10
作者 Li Layuan & Li Chunlin(Department of Computer Science & Engineering. Wuhan Transportation University,430063,P . R. China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1999年第4期34-41,共8页
This paper discusses the algorithms for achieving global states and self-stabilizationfor communication protocols. It first describes a primary algorithm including its suitability forachieving global states and limita... This paper discusses the algorithms for achieving global states and self-stabilizationfor communication protocols. It first describes a primary algorithm including its suitability forachieving global states and limitation of self-stabilization for communication protocols, and thenpresents an improved algorithm that can be suitable to achieve global states and can be also usedto self-stabilizing communication protocols. Filially, it gives the proof of correctness and analysis ofcomplexity of the improved algorithm, and verifies its availability and efficiency by illustrating anexample protocol. 展开更多
关键词 Communication protocols Algorithm for achieving global states Self-stabilization Computer networks Multimedia communication networks.
在线阅读 下载PDF
The Chinese Diaspora and Disability/Rehabilitation in the United States
11
作者 Paul Leung 《中国康复理论与实践》 CSCD 2006年第9期768-770,共3页
In this article, I will discuss disability issues as a second and a half generation American of Chinese descent who has worked with persons with disabilities, has taught rehabilitation counseling as well as having bee... In this article, I will discuss disability issues as a second and a half generation American of Chinese descent who has worked with persons with disabilities, has taught rehabilitation counseling as well as having been a rehabilitation psychologist for more than 35 years in the U.S. and Australia. I am pleased to be able to share some of my thoughts and experiences in this article that is a bit less formal than what you may expect in a professional journal. Though I hope that what I share will provoke some thinking and action from those who read these words. 展开更多
关键词 Chinese diaspora DISABILITY REHABILITATION United states
在线阅读 下载PDF
Occupational Therapy Evaluation for Stroke Adults in the United States
12
作者 YANG Shan-li 《中国康复理论与实践》 CSCD 2010年第4期399-400,共2页
Of the 700,000 people in the United States who experience a new or recurrent stroke each year,more than 500,000 survive(American Stroke Association,2007)[1]. Occupational therapy practitioners are critical rehabilitat... Of the 700,000 people in the United States who experience a new or recurrent stroke each year,more than 500,000 survive(American Stroke Association,2007)[1]. Occupational therapy practitioners are critical rehabilitation professionals for stroke survivors. 展开更多
关键词 Occupational Therapy Evaluation for Stroke Adults in the United states
在线阅读 下载PDF
Road traffic states estimation algorithm based on matching of regional traffic attracters 被引量:3
13
作者 徐东伟 董宏辉 +1 位作者 贾利民 田寅 《Journal of Central South University》 SCIE EI CAS 2014年第5期2100-2107,共8页
To effectively solve the traffic data problems such as data invalidation in the process of the acquisition of road traffic states,a road traffic states estimation algorithm based on matching of the regional traffic at... To effectively solve the traffic data problems such as data invalidation in the process of the acquisition of road traffic states,a road traffic states estimation algorithm based on matching of the regional traffic attracters was proposed in this work.First of all,the road traffic running states were divided into several different modes.The concept of the regional traffic attracters of the target link was put forward for effective matching.Then,the reference sequences of characteristics of traffic running states with the contents of the target link's traffic running states and regional traffic attracters under different modes were established.In addition,the current and historical regional traffic attracters of the target link were matched through certain matching rules,and the historical traffic running states of the target link corresponding to the optimal matching were selected as the initial recovery data,which were processed with Kalman filter to obtain the final recovery data.Finally,some typical expressways in Beijing were adopted for the verification of this road traffic states estimation algorithm.The results prove that this traffic states estimation approach based on matching of the regional traffic attracters is feasible and can achieve a high accuracy. 展开更多
关键词 road traffic regional traffic attracter traffic state data recovery MATCHING
在线阅读 下载PDF
Real-time road traffic states estimation based on kernel-KNN matching of road traffic spatial characteristics 被引量:3
14
作者 XU Dong-wei 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2453-2464,共12页
The accurate estimation of road traffic states can provide decision making for travelers and traffic managers. In this work,an algorithm based on kernel-k nearest neighbor(KNN) matching of road traffic spatial charact... The accurate estimation of road traffic states can provide decision making for travelers and traffic managers. In this work,an algorithm based on kernel-k nearest neighbor(KNN) matching of road traffic spatial characteristics is presented to estimate road traffic states. Firstly, the representative road traffic state data were extracted to establish the reference sequences of road traffic running characteristics(RSRTRC). Secondly, the spatial road traffic state data sequence was selected and the kernel function was constructed, with which the spatial road traffic data sequence could be mapped into a high dimensional feature space. Thirdly, the referenced and current spatial road traffic data sequences were extracted and the Euclidean distances in the feature space between them were obtained. Finally, the road traffic states were estimated from weighted averages of the selected k road traffic states, which corresponded to the nearest Euclidean distances. Several typical links in Beijing were adopted for case studies. The final results of the experiments show that the accuracy of this algorithm for estimating speed and volume is 95.27% and 91.32% respectively, which prove that this road traffic states estimation approach based on kernel-KNN matching of road traffic spatial characteristics is feasible and can achieve a high accuracy. 展开更多
关键词 road traffic kernel function k nearest neighbor (KNN) state estimation spatial characteristics
在线阅读 下载PDF
Effect of intermediate principal stress on strength of soft rock under complex stress states 被引量:2
15
作者 马宗源 廖红建 党发宁 《Journal of Central South University》 SCIE EI CAS 2014年第4期1583-1593,共11页
A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/s... A series of numerical simulations of conventional and true triaxial tests for soft rock materials using the three-dimensional finite difference code FLAC3D were presented. A hexahedral element and a strain hardening/softening constitutive model based on the unified strength theory(UST) were used to simulate both the consolidated-undrained(CU) triaxial and the consolidated-drained(CD) true triaxial tests. Based on the results of the true triaxial tests simulation, the effect of the intermediate principal stress on the strength of soft rock was investigated. Finally, an example of an axial compression test for a hard rock pillar with a soft rock interlayer was analyzed using the two-dimensional finite difference code FLAC. The CD true triaxial test simulations for diatomaceous soft rock suggest the peak and residual strengths increase by 30% when the effect of the intermediate principal stress is taken into account. The axial compression for a rock pillar indicated the peak and residual strengths increase six-fold when the soft rock interlayer approached the vertical and the effect of the intermediate principal stress is taken into account. 展开更多
关键词 soft rock strength strain-softening complex stress state effect of intermediate principal stress
在线阅读 下载PDF
Advances in integrated polarization detectors with innovative features
16
作者 BU Yong-Hao ZHOU Jing +8 位作者 DENG Jie WANG Ruo-Wen YE Tao SHI Meng-Die HUANG Jun-Wei ZHANG Yu-Jie NING Jun LU Wei CHEN Xiao-Shuang 《红外与毫米波学报》 北大核心 2025年第3期371-383,共13页
The polarization properties of light are widely applied in imaging,communications,materials analy⁃sis,and life sciences.Various methods have been developed that can measure the polarization information of a target.How... The polarization properties of light are widely applied in imaging,communications,materials analy⁃sis,and life sciences.Various methods have been developed that can measure the polarization information of a target.However,conventional polarization detection systems are often bulky and complex,limiting their poten⁃tial for broader applications.To address the challenges of miniaturization,integrated polarization detectors have been extensively explored in recent years,achieving significant advancements in performance and functionality.In this review,we focus mainly on integrated polarization detectors with innovative features,including infinitely high polarization discrimination,ultrahigh sensitivity to polarization state change,full Stokes parameters measure⁃ment,and simultaneous perception of polarization and other key properties of light.Lastly,we discuss the oppor⁃tunities and challenges for the future development of integrated polarization photodetectors. 展开更多
关键词 integrated polarization detector infinite polarization extinction ratio polarization state change detection full-Stokes multidimensional detection
在线阅读 下载PDF
Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
17
作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 Normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
在线阅读 下载PDF
Second-Order Topological Insulators in 2D Electronic Materials
18
作者 FENG Xiao-ran NIU Cheng-wang +1 位作者 HUANG Bai-biao DAI Ying 《物理学进展》 北大核心 2025年第1期1-31,共31页
Higher-order band topology not only enriches our understanding of topological phases but also unveils pioneering lower-dimensional boundary states,which harbors substantial potential for next-generation device applica... Higher-order band topology not only enriches our understanding of topological phases but also unveils pioneering lower-dimensional boundary states,which harbors substantial potential for next-generation device applications.The distinct electronic configurations and tunable attributes of two-dimensional materials position them as a quintessential platform for the realization of second-order topological insulators(SOTIs).This article provides an overview of the research progress in SOTIs within the field of two-dimensional electronic materials,focusing on the characterization of higher-order topological properties and the numerous candidate materials proposed in theoretical studies.These endeavors not only enhance our understanding of higher-order topological states but also highlight potential material systems that could be experimentally realized. 展开更多
关键词 second order topological insulator corner state 2D electronic material
在线阅读 下载PDF
Evaluation of detonation performance of explosives ICM-101,ONC,and TNAZ based on improved VHL equation of state
19
作者 Yong Han Qin Liu +2 位作者 Yingliang Duan Yaqi Zhao Xinping Long 《Defence Technology(防务技术)》 2025年第2期83-97,共15页
Detonation performance is crucial for evaluating the power of high explosives(HEs),and the equation of state(EOS)that accurately describes the high-temperature,high-pressure,and high-temperature,medium-pressure states... Detonation performance is crucial for evaluating the power of high explosives(HEs),and the equation of state(EOS)that accurately describes the high-temperature,high-pressure,and high-temperature,medium-pressure states of detonation products is key to assessing the damage efficiency of these energetic materials.This article examines the limitations of the VLW EOS in representing the thermodynamic states of explosive detonation gas products under high-temperature and medium-to high-pressure conditions.A new gas EOS for detonation products,called VHL(Virial-Han-Long),is proposed.The accuracy of VHL in describing gas states under high-temperature and medium-to high-pressure conditions is verified,and its performance in evaluating explosive detonation and working capabilities is explored.The results demonstrate that VHL exhibits high precision in calculating detonation performance.Subsequently,the detonation performance of three new HEs(ICM-101,ONC,and TNAZ)was calculated and compared to traditional HEs(TATB,CL-20,and HMX).The results indicate that ONC has superior detonation performance compared to the other explosives,while ICM-101 shows a detonation velocity similar to CL-20 but with slightly lower detonation pressure.The detonation characteristics of TNAZ are comparable to those of the standard HE HMX.From the perspective of products,considering the comprehensive work performance(mechanical work and detonation heat),both ONC and ICM-101demonstrate relatively superior performance. 展开更多
关键词 Equation of state Detonation performance Working capability THERMODYNAMICS High explosive
在线阅读 下载PDF
Static compressive mechanical properties and disturbed state concept-based theoretical model of gypsum rocks with coupled influences of wet-dry cycles and flow rates
20
作者 JIANG Song HUANG Ming +2 位作者 WANG Gang XU Chao-shui XIONG Jun 《Journal of Central South University》 2025年第7期2638-2660,共23页
Gypsum rocks are highly susceptible to mechanical deterioration under the coupled effects of wet-dry(W-D)cycles and flow rates,which significantly influence the stability of underground excavations.Despite extensive r... Gypsum rocks are highly susceptible to mechanical deterioration under the coupled effects of wet-dry(W-D)cycles and flow rates,which significantly influence the stability of underground excavations.Despite extensive research on the effects of W-D cycles,the coupling influence of flow rates and W-D cycles on gypsum rocks remains poorly understood.This study investigates the mechanical behavior and deterioration mechanisms of gypsum rocks subjected to varying W-D cycles and flow rate conditions.Axial compression tests,along with nuclear magnetic resonance(NMR)techniques,were employed to analyze the stress-strain response and microstructural changes.Based on the disturbed state concept(DSC)theory,a W-D deterioration model and a DSC-based constitutive model were developed to describe the degradation trends and mechanical responses of gypsum rocks under different conditions.The results demonstrate that key mechanical indices,elastic modulus,cohesion,uniaxial compressive strength(UCS),and internal friction angle,exhibit logarithmic declines with increasing W-D cycles,with higher flow rates accelerating the deterioration process.The theoretical models accurately capture the nonlinear compaction behavior,peak stress,and post-peak response of gypsum specimens.This study provides valuable insights for predicting the mechanical behavior of gypsum rocks and improving the stability assessments of underground structures under complex environmental conditions. 展开更多
关键词 gypsum rocks wet-dry cycles flow rates mechanical properties disturbed state concept
在线阅读 下载PDF
上一页 1 2 13 下一页 到第
使用帮助 返回顶部