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Unified Framework Towards Flexible Multiple Access Schemes for 5G 被引量:1
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作者 SUN Qi WANG Sen +1 位作者 HAN Shuangfeng Chih-Lin I 《ZTE Communications》 2016年第4期26-34,共9页
Non-orthogonal multiple access (NOMA) schemes have achieved great attention recently and been considered as a crucial compo-nent for 5G wireless networks since they can efficiently enhance the spectrum efficiency, s... Non-orthogonal multiple access (NOMA) schemes have achieved great attention recently and been considered as a crucial compo-nent for 5G wireless networks since they can efficiently enhance the spectrum efficiency, support massive connections and poten-tially reduce access latency via grant free access. In this paper, we introduce the candidate NOMA solutions in 5G networks, com-paring the principles, key features, application scenarios, transmitters and receivers, etc. In addition, a unified framework of these multiple access schemes are proposed to improve resource utilization, reduce the cost and support the flexible adaptation of multi-ple access schemes. Further, flexible multiple access schemes in 5G systems are discussed. They can support diverse deployment scenarios and traffic requirements in 5G. Challenges and future research directions are also highlighted to shed some lights for the standardization in 5G. 展开更多
关键词 5G non-orthogonal multiple access unified framework flexible multiple access
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Unified numerical predictor-corrector guidance based on characteristic model
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作者 MENG Bin ZHANG Hangning ZHAO Yunbo 《中国空间科学技术(中英文)》 CSCD 北大核心 2024年第4期40-49,共10页
Aerocapture is one of the key technologies for low-cost transportation,with high demands of autonomy,accuracy,and robustness of guidance and control,due to its high reliability requirements for only one chance of tryi... Aerocapture is one of the key technologies for low-cost transportation,with high demands of autonomy,accuracy,and robustness of guidance and control,due to its high reliability requirements for only one chance of trying.A unified numerical predictor-corrector guidance method based on characteristic models for aerocapture is proposed.The numerical predictor-corrector guidance method is used to achieve autonomy and high accuracy,and the characteristic model control method is introduced to achieve robustness.At the same time,by transforming path constraints,characteristic model equations including apogee deviation and altitude differentiation are established.Based on the characteristic model equations,a unified guidance law which can satisfy path constraints and guidance objectives simultaneously is designed.In guidance problems,guidance deviation is not directly obtained from the output of the dynamics at present,but is calculated through integral and algebraic equations.Therefore,the method of directly discretizing differential equations cannot be used to establish characteristic models,which brings great difficulty to characteristic modeling.A method for characteristic modeling of guidance problems is proposed,and convergence analysis of the proposed guidance law is also provided.Finally,a joint numerical simulation of guidance and control considering navigation deviation and various uncertainties is conducted to verify the effectiveness of the proposed method.The proposed unified method can be extended to general aerodynamic entry guidance designs,providing theoretical and methodological support for them. 展开更多
关键词 aerocapture path constraint characteristic model unified numerical predictor-corrector guidance CONVERGENCE
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Isotopic dependence of the yield ratios of light fragments from different projectiles and their unified neutron skin thicknesses
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作者 Ting-Zhi Yan Shan Li 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期228-236,共9页
The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(ever... The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112 Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)model.The neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in IQMD.We defined the unified neutron skin thickness asΔRnp=<r^(2)>^(1∕2) n−<r^(2)>^(1∕2)p,which was negative for neutron-deficient nuclei.The unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling behavior.The yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were studied.The results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact parameters.In addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains. 展开更多
关键词 Exotic nuclei unified neutron skin thickness Yield ratios IQMD
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Unified deep learning model for predicting fundus fluorescein angiography image from fundus structure image
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作者 Yiwei Chen Yi He +3 位作者 Hong Ye Lina Xing Xin Zhang Guohua Shi 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第3期105-113,共9页
The prediction of fundus fluorescein angiography(FFA)images from fundus structural images is a cutting-edge research topic in ophthalmological image processing.Prediction comprises estimating FFA from fundus camera im... The prediction of fundus fluorescein angiography(FFA)images from fundus structural images is a cutting-edge research topic in ophthalmological image processing.Prediction comprises estimating FFA from fundus camera imaging,single-phase FFA from scanning laser ophthalmoscopy(SLO),and three-phase FFA also from SLO.Although many deep learning models are available,a single model can only perform one or two of these prediction tasks.To accomplish three prediction tasks using a unified method,we propose a unified deep learning model for predicting FFA images from fundus structure images using a supervised generative adversarial network.The three prediction tasks are processed as follows:data preparation,network training under FFA supervision,and FFA image prediction from fundus structure images on a test set.By comparing the FFA images predicted by our model,pix2pix,and CycleGAN,we demonstrate the remarkable progress achieved by our proposal.The high performance of our model is validated in terms of the peak signal-to-noise ratio,structural similarity index,and mean squared error. 展开更多
关键词 Fundus fluorescein angiography image fundus structure image image translation unified deep learning model generative adversarial networks
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Unified Control Theory from PID to ACPID
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作者 Zhezhao Zeng Yuqi Tang 《Advances in Pure Mathematics》 2024年第7期523-545,共23页
To address the challenge of achieving unified control across diverse nonlinear systems, a comprehensive control theory spanning from PID (Proportional-Integral-Derivative) to ACPID (Auto-Coupling PID) has been propose... To address the challenge of achieving unified control across diverse nonlinear systems, a comprehensive control theory spanning from PID (Proportional-Integral-Derivative) to ACPID (Auto-Coupling PID) has been proposed. The primary concept is to unify all intricate factors, including internal dynamics and external bounded disturbance, into a single total disturbance. This enables the mapping of various nonlinear systems onto a linear disturbance system. Based on the theory of PID control and the characteristic equation of a critically damping system, Zeng’s stabilization rules (ZSR) and an ACPID control force based on a single speed factor have been designed. ACPID control theory is both simple and practical, with significant scientific significance and application value in the field of control engineering. 展开更多
关键词 Insert Nonlinear Systems PID Control ACPID Control Total Disturbance unified Control Theory Zeng’s Stabilization Rules (ZSR)
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CHINA’S PUSH FOR UNIFIED NATIONAL MARKET BRINGS NEW OPPORTUNITIES
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作者 Tom Fowdy 《China Report ASEAN》 2024年第2期79-79,共1页
In recent years,China has implemented measures to advance the building of a unified national market,aiming to boost domestic demand and consolidate the foundations of its economic recovery.In March 2022,the Chinese go... In recent years,China has implemented measures to advance the building of a unified national market,aiming to boost domestic demand and consolidate the foundations of its economic recovery.In March 2022,the Chinese government issued a guideline on accelerating the construction of a unified national market.The issue was also a focus at the annual Central Economic Work Conference held in December 2023. 展开更多
关键词 unified PUSH measures
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Passive neutron multiplicity device for^(240)Pu measurement based on FPGA
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作者 Yan Zhang Hao-Ran Zhang +6 位作者 Ren-Bo Wang Ming-Yu Li Rui Chen Hai-Tao Wang Xiang-Ting Meng Shu-Min Zhou Bin Tang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第9期141-154,共14页
A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide fuel.FH-NCM/S1 adopt... A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide fuel.FH-NCM/S1 adopts an inte-grated approach,combining the shift register analysis mode with the pulse-position timestamp mode using an FPGA.The optimal effective length of the^(3)He neutron detector was determined to be 30 cm,and the thickness of the graphite reflector was ascertained to be 15 cm through MCNP simulations.After fabricating the device,calibration measurements were per-formed using a^(252)Cf neutron source;a detection efficiency of 43.07%and detector die-away time of 55.79μs were observed.Nine samples of plutonium oxide were measured under identical conditions using the FH-NCM/S1 in shift register analysis mode and a plutonium waste multiplicity counter.The obtained double rates underwent corrections for detection efficiency(ε)and double gate fraction(f_(d)),resulting in corrected double rates(D_(c)),which were used to validate the accuracy of the shift register analysis mode.Furthermore,the device exhibited fluctuations in the measurement results,and within a single 20 s measurement,these fluctuations remained below 10%.After 30 cycles,the relative error in the mass of^(240)Pu was less than 5%.Finally,correlation calculations confirmed the robust consistency of both measurement modes.This study holds specific significance for the subsequent design and development of neutron multiplicity devices. 展开更多
关键词 Spent fuel Non-destructive assay Neutron multiplicity ^(240)Pu FPGA
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Assessing the range of blasting-induced cracks in the surrounding rock of deeply buried tunnels based on the unified strength theory
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作者 LI Liang CHEN Jia-jun +3 位作者 ZHAO Lian-heng HE Ke-pei HU Shi-hong LI Hua-long 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2341-2364,共24页
Blasting-induced cracks in the rock surrounding deeply buried tunnels can result in water gushing and rock mass collapse,posing significant safety risks.However,previous theoretical studies on the range of blasting-in... Blasting-induced cracks in the rock surrounding deeply buried tunnels can result in water gushing and rock mass collapse,posing significant safety risks.However,previous theoretical studies on the range of blasting-induced cracks often ignore the impact of the in-situ stress,especially that of the intermediate principal stress.The particle displacement−crack radius relationship was established in this paper by utilizing the blasthole cavity expansion equation,and theoretical analytical formulas of the stress−displacement relationship and the crack radius were derived with unified strength theory to accurately assess the range of cracks in deep surrounding rock under a blasting load.Parameter analysis showed that the crushing zone size was positively correlated with in-situ stress,intermediate principal stress,and detonation pressure,whereas negatively correlated with Poisson ratio and decoupling coefficient.The dilatancy angle-crushing zone size relationship exhibited nonmonotonic behavior.The relationships in the crushing zone and the fracture zone exhibited opposite trends under the influence of only in-situ stress or intermediate principal stress.As the in-situ stress increased from 0 to 70 MPa,the rate of change in the crack range and the attenuation rate of the peak vibration velocity gradually slowed. 展开更多
关键词 deep drilling and blasting cracks in surrounding rock unified strength theory intermediate principle stress in-situ stress cavity expansion dilatancy characteristics
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FINITE RANGE SET WITH TRUNCATED MULTIPLICITY FOR MEROMORPHIC FUNCTIONS ON SOME COMPLEX DISC
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作者 WANG Yu-ting CAO Hong-zhe 《数学杂志》 2024年第5期383-396,共14页
In this paper,we consider the truncated multiplicity finite range set problem of meromorphic functions on some complex disc.By using the value distribution theory of meromorphic functions,we establish a second main th... In this paper,we consider the truncated multiplicity finite range set problem of meromorphic functions on some complex disc.By using the value distribution theory of meromorphic functions,we establish a second main theorem for meromorphic functions with finite growth index which share meromorphic functions(may not be small functions).As its application,we also extend the result of a finite range set with truncated multiplicity. 展开更多
关键词 meromorphic functions finite growth index complex disc finite range set trun-cated multiplicity
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The Unified Field
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作者 Joseph H. (Cass) Forrington 《Journal of Modern Physics》 2024年第7期1010-1035,共26页
This is a Unified Field description based on the holographic Time Dilation Cosmology, TDC, model, which is an eternal continuum evolving forward in the forward direction of time, at the speed of light, c, at an invari... This is a Unified Field description based on the holographic Time Dilation Cosmology, TDC, model, which is an eternal continuum evolving forward in the forward direction of time, at the speed of light, c, at an invariant 1 s/s rate of time. This is the Fundamental Direction of Evolution, FDE. There is also an evolution down time dilation gradients, the Gravitational Direction of Evolution, GDE. These evolutions are gravity, which is the evolutionary force in time. Gravitational velocities are compensation for the difference in the rate of time, dRt, in a dilation field, and the dRtis equal to the compensatory velocity’s percentage of c, and is a measure of the force in time inducing the velocity. In applied force induced velocities, the dRt is a measure of the resistance in time to the induced velocity, which might be called “anti-gravity” or “negative gravity”. The two effects keep the continuum uniformly evolving forward at c. It is demonstrated that gravity is already a part of the electromagnetic field equations in way of the dRt element contained in the TDC velocity formula. Einstein’s energy formula is defined as a velocity formula and a modified version is used for charged elementary particle solutions. A time dilation-based derivation of the Lorentz force ties gravity directly to the electromagnetic field proving the unified field of gravity and the EMF. It is noted how we could possibly create gravity drives. This is followed by a discussion of black holes, proving supermassive objects, like massive black hole singularities, are impossible, and that black holes are massless Magnetospheric Eternally Collapsing Objects (MECOs) that are vortices in spacetime. . 展开更多
关键词 unified Field GRAVITY Anti-Gravity Astrophysics Einstein General Relativity Special Relativity Galactic Rotation Velocities Time Dilation SPACETIME Space Time Spacetime Continuum Quantum Continuum MECO Black Hole Event Horizon Timelike Spacelike Lightlike
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Comparative Study on the Policy of Multiplicity Issues in Clinical Trials at Home and Abroad
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作者 Gong Jingran Chang Yingnan +1 位作者 Qiao Jiahui Chen Yuwen 《Asian Journal of Social Pharmacy》 2024年第1期43-49,共7页
Objective To study the content of China’s guiding principles on multiplicity issues in clinical trials,and to provide reference for the revision of China’s relevant guiding principles.Methods Based on ICH E9,the sim... Objective To study the content of China’s guiding principles on multiplicity issues in clinical trials,and to provide reference for the revision of China’s relevant guiding principles.Methods Based on ICH E9,the similarities and differences of the guiding principles of US Food and Drug Administration(FDA),European Medicines Agency(EMA),and National Medical Products Administration(NMPA)on the multiplicity issues in clinical trials were compared one by one.Results and Conclusion In general,NMPA guidelines are based on ICH E9,but in detail,the guidelines of FDA and EMA focus differently on the multiplicity issues.Therefore,NMPA guidelines need to be detailed and comprehensive.NMPA guidelines can be refined by referring to foreign guidelines to improve the practical guiding significance for clinical research and promote the level of domestic clinical trials in line with international standards. 展开更多
关键词 clinical trial multiplicity issue solution strategy
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Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies
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作者 Guangyong Zhang Qing Yao +9 位作者 Chubing Long Pengcheng Yi Jiali Song Luojia Wu Wei Wan Xiuqin Rao Yue Lin Gen Wei Jun Ying Fuzhou Hua 《Neural Regeneration Research》 SCIE CAS 2025年第3期779-793,共15页
Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple rol... Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood–brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases. 展开更多
关键词 blood–brain barrier MACROPHAGES MONOCYTES multiple sclerosis NEUROINFLAMMATION review therapy
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Towards a Unified Single Analysis Framework Embedded with Multiple Spatial and Time Discretized Methods for Linear Structural Dynamics
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作者 David Tae Kumar K.Tamma 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第5期843-885,共43页
We propose a novel computational framework that is capable of employing different time integration algorithms and different space discretized methods such as the Finite Element Method,particle methods,and other spatia... We propose a novel computational framework that is capable of employing different time integration algorithms and different space discretized methods such as the Finite Element Method,particle methods,and other spatial methods on a single body sub-dividedintomultiple subdomains.This is in conjunctionwithimplementing thewell known Generalized Single Step Single Solve(GS4)family of algorithms which encompass the entire scope of Linear Multistep algorithms that have been developed over the past 50 years or so and are second order accurate into the Differential Algebraic Equation framework.In the current state of technology,the coupling of altogether different time integration algorithms has been limited to the same family of algorithms such as theNewmarkmethods and the coupling of different algorithms usually has resulted in reduced accuracy in one or more variables including the Lagrange multiplier.However,the robustness and versatility of the GS4 with its ability to accurately account for the numerical shifts in various time schemes it encompasses,overcomes such barriers and allows a wide variety of arbitrary implicit-implicit,implicit-explicit,and explicit-explicit pairing of the various time schemes while maintaining the second order accuracy in time for not only all primary variables such as displacement,velocity and acceleration but also the Lagrange multipliers used for coupling the subdomains.By selecting an appropriate spatialmethod and time scheme on the area with localized phenomena contrary to utilizing a single process on the entire body,the proposed work has the potential to better capture the physics of a given simulation.The method is validated by solving 2D problems for the linear second order systems with various combination of spatial methods and time schemes with great flexibility.The accuracy and efficacy of the present work have not yet been seen in the current field,and it has shown significant promise in its capabilities and effectiveness for general linear dynamics through numerical examples. 展开更多
关键词 Time integration structural dynamics multiple scale and multiple methods ordinary differential equations differential algebraic equations
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Unified Solution Method of Rectangular Plate Elastic Bending 被引量:9
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作者 许琪楼 姬同庚 +2 位作者 姜锐 唐国明 姬鸿恩 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期241-248,共8页
The bending of rectangular plate is divided into the generalized statically determinate bending and the generalized statically indeterminate bending based on the analysis of the completeness of calculating condition a... The bending of rectangular plate is divided into the generalized statically determinate bending and the generalized statically indeterminate bending based on the analysis of the completeness of calculating condition at the corner point. The former can be solved directly by the equilibrium differential equation and the boundary conditions of four edges of the plate. The latter can be solved by using the superposition principle. Making use of the recommended method, the bending of the plate with all kinds of... 展开更多
关键词 bending of elastic thin plate rectangular plate unified solution method
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Analysis of plane strain bending of a strain hardening curved beam based on unified yield criterion 被引量:1
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作者 傅军 庞苗 +2 位作者 宋广远 张永强 杨博 《Journal of Southeast University(English Edition)》 EI CAS 2016年第3期339-345,共7页
The analysis of plane strain elastic-plastic bending of a linear strain hardening curved beam with a narrow rectangular cross section subjected to couples at its end is conducted based on a unified yield criterion. Th... The analysis of plane strain elastic-plastic bending of a linear strain hardening curved beam with a narrow rectangular cross section subjected to couples at its end is conducted based on a unified yield criterion. The solutions for the mechanical properties of plane strain bending are derived, which are adapted for various kinds of non-strength differential materials and can be degenerated to those based on the Tresca, von Mises, and twin-shear yield criteria. The dependences of the two critical bending moments, the radii of the interfaces between the elastic and plastic regions and the radial displacements of the points at the symmetrical plane on different yield criteria and Poisson’s ratios are discussed. The results show that the influences of different yield criteria and Poisson’s ratio on the two critical bending moments, the radii of the interfaces between the elastic and plastic regions and the radial displacements of the points at the symmetrical plane of the curved beam are significant. Once the value of bis obtained by experiments, the yield criterion and the corresponding solution for the materials of interest are then determined. 展开更多
关键词 curved beam plane strain strain hardening elastic-plastic bending unified yield criterion
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基于OPC Unified Architecture的服务器研究 被引量:8
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作者 孙发 刘枫 《仪器仪表标准化与计量》 2006年第5期14-17,共4页
首先介绍现有OPC规范以及其存在的不足,然后介绍OPC基金会即将推出的OPCUnifiedArchitecture规范,并重点研究OPCUnifiedArchitecture服务器的实现机制及方法,通过与现有OPC规范的比较,揭示OPCUA在平台无关性、可互操作性、可靠性等方面... 首先介绍现有OPC规范以及其存在的不足,然后介绍OPC基金会即将推出的OPCUnifiedArchitecture规范,并重点研究OPCUnifiedArchitecture服务器的实现机制及方法,通过与现有OPC规范的比较,揭示OPCUA在平台无关性、可互操作性、可靠性等方面的显著优势。 展开更多
关键词 OPC OPC unified ARCHITECTURE 可互操作
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Unified symmetry of nonholonomic mechanical systems with variable mass 被引量:7
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作者 夏丽莉 李元成 +1 位作者 后其宝 王静 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第5期903-906,共4页
Based on the total time derivative along the trajectory of the system the definition and the criterion for a unified symmetry of nonholonomic mechanical system with variable mass are presented in this paper. A new con... Based on the total time derivative along the trajectory of the system the definition and the criterion for a unified symmetry of nonholonomic mechanical system with variable mass are presented in this paper. A new conserved quantity, as well as the Noether conserved quantity and the Hojman conserved quantity, deduced from the unified symmetry, are also obtained, An example is given to illustrate the application of the results. 展开更多
关键词 variable mass nonholonomic mechanical system unified symmetry conserved quantity
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A unified gas-kinetic scheme for multiscale and multicomponent flow transport 被引量:4
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作者 Tianbai XIAO Kun XU Qingdong CAI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第3期355-372,共18页
Compressible flows exhibit a diverse set of behaviors, where individual particle transports and their collective dynamics play different roles at different scales. At the same time, the atmosphere is composed of diffe... Compressible flows exhibit a diverse set of behaviors, where individual particle transports and their collective dynamics play different roles at different scales. At the same time, the atmosphere is composed of different components that require additional degrees of freedom for representation in computational fluid dynamics. It is challenging to construct an accurate and efficient numerical algorithm to faithfully represent multiscale flow physics across different regimes. In this paper, a unified gas-kinetic scheme(UGKS) is developed to study non-equilibrium multicomponent gaseous flows. Based on the Boltzmann kinetic equation, an analytical space-time evolving solution is used to construct the discretized equations of gas dynamics directly according to cell size and scales of time steps, i.e., the so-called direct modeling method. With the variation in the ratio of the numerical time step to the local particle collision time(or the cell size to the local particle mean free path), the UGKS automatically recovers all scale-dependent flows over the given domain and provides a continuous spectrum of the gas dynamics. The performance of the proposed unified scheme is fully validated through numerical experiments.The UGKS can be a valuable tool to study multiscale and multicomponent flow physics. 展开更多
关键词 unified gas-kinetic scheme(UGKS) multiscale modeling MULTICOMPONENT flow
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Unified analytical solution for deep circular tunnel with consideration of seepage pressure,grouting and lining 被引量:5
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作者 LI Xue-feng DU Shou-ji CHEN Bing 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第6期1483-1493,共11页
A new unified analytical solution is presented for predicting the range of plastic zone and stress distributions around a deep circular tunnel in a homogeneous isotropic continuous medium. The rock mass, grouting zone... A new unified analytical solution is presented for predicting the range of plastic zone and stress distributions around a deep circular tunnel in a homogeneous isotropic continuous medium. The rock mass, grouting zone and lining are assumed as elastic-perfectly plastic and governed by the unified strength theory(UST). This new solution has made it possible to consider the interaction between seepage pressure, lining, grouting and rock mass, and the intermediate principal stress effect together. Moreover, parametric analysis is carried out to identify the influence of the related parameters on the plastic zone radius. Under the given conditions, the results show that the plastic zone radius decreases with an increasing cohesion, internal friction angle and hydraulic conductivity of lining and unified failure criterion parameter, respectively; whereas the plastic zone radius increases with the growth of elasticity modulus of lining. Comparison of results from the new solution and the other published one shows well agreement and provides confidence in the new solution proposed. 展开更多
关键词 unified strength theory (UST) INTERMEDIATE principal stress SEEPAGE pressure GROUTING LINING analytical solution
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Unified Water Gravity Wave Theory and Improved Linear Wave 被引量:3
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作者 Fu Yuhua Senior Engineer, Structural Engineering Department, China Offshore Oil Development and Engineering Corp., Beijing 《China Ocean Engineering》 SCIE EI 1992年第1期57-64,共8页
Based on Least Square Method, this paper presents variational principle for handling various water gravity wave theories and the unified water gravity wave theory was given. By using this variational principle of unif... Based on Least Square Method, this paper presents variational principle for handling various water gravity wave theories and the unified water gravity wave theory was given. By using this variational principle of unified water wave theory, two kinds of improved linear waves were derived. The first one uses the same boundary conditions which were applied to derive 5-order Stokes wave. The second one uses the accurate boundary conditions (Eqs. 11 and 12). The two improved linear waves were compared with the existing linear wave. 展开更多
关键词 WAVE unified theory improved linear wave
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