期刊文献+
共找到128篇文章
< 1 2 7 >
每页显示 20 50 100
Numerical study on wave loads and motions of two ships advancing in waves by using three-dimensional translating-pulsating source 被引量:10
1
作者 Yong Xu Wen-Cai Dong 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第4期494-502,共9页
A frequency domain analysis method based on the three-dimensional translating-pulsating (3DTP) source Green function is developed to investigate wave loads and free motions of two ships advancing on parallel course ... A frequency domain analysis method based on the three-dimensional translating-pulsating (3DTP) source Green function is developed to investigate wave loads and free motions of two ships advancing on parallel course in waves. Two experiments are carried out respectively to mea- sure the wave loads and the free motions for a pair of side-by- side arranged ship models advancing with an identical speed in head regular waves. For comparison, each model is also tested alone. Predictions obtained by the present solution are found in favorable agreement with the model tests and are more accurate than the traditional method based on the three dimensional pulsating (3DP) source Green function. Numer- ical resonances and peak shift can be found in the 3DP pre- dictions, which result from the wave energy trapped in the gap between two ships and the extremely inhomogeneous wave load distribution on each hull. However, they can be eliminated by 3DTP, in which the speed affects the free sur- face and most of the wave energy can be escaped from the gap. Both the experiment and the present prediction show that hydrodynamic interaction effects on wave loads and free motions are significant. The present solver may serve as a validated tool to predict wave loads and motions of two ves- sels under replenishment at sea, and may help to evaluate the hydrodynamic interaction effects on the ships safety in replenishment operation. 展开更多
关键词 Hydrodynamic interaction - Wave loads ~Ship motions ~ Model test ~ three-dimensional translating-pulsating source ~ Underway replenishment
下载PDF
Dynamic strength of rock with single planar joint under various loading rates at various angles of loads applied 被引量:6
2
作者 Pei-Yun Shu Hung-Hui Li +1 位作者 Tai-Tien Wang Tzuu-Hsing Ueng 《Journal of Rock Mechanics and Geotechnical Engineering》 CSCD 2018年第3期545-554,共10页
Intact rock-like specimens and specimens that include a single, smooth planar joint at various angles are prepared for split Hopkinson pressure bar(SHPB) testing. A buffer pad between the striker bar and the inciden... Intact rock-like specimens and specimens that include a single, smooth planar joint at various angles are prepared for split Hopkinson pressure bar(SHPB) testing. A buffer pad between the striker bar and the incident bar of an SHPB apparatus is used to absorb some of the shock energy. This can generate loading rates of 20.2-4627.3 GPa/s, enabling dynamic peak stresses/strengths and associated failure patterns of the specimens to be investigated. The effects of the loading rate and angle of load applied on the dynamic peak stresses/strengths of the specimens are examined. Relevant experimental results demonstrate that the failure pattern of each specimen can be classified as four types: Type A, integrated with or without tiny flake-off; Type B, slide failure; Type C, fracture failure; and Type D, crushing failure. The dynamic peak stresses/strengths of the specimens that have similar failure patterns increase linearly with the loading rate, yielding high correlations that are evident on semi-logarithmic plots. The slope of the failure envelope is the smallest for slide failure, followed by crushing failure, and that of fracture failure is the largest. The magnitude of the plot slope of the dynamic peak stress against the loading rate for the specimens that are still integrated after testing is between that of slide failure and crushing failure. The angle of application has a limited effect on the dynamic peak stresses/strengths of the specimens regardless of the failure pattern, but it affects the bounds of the loading rates that yield each failure pattern, and thus influences the dynamic responses of the single jointed specimen. Slide failure occurs at the lowest loading rate of any failure, but can only occur in single jointed specimen that allows sliding.Crushing failure is typically associated with the largest loading rate, and fracture failure may occur when the loading rate is between the boundaries for slide failure and crushing failure. 展开更多
关键词 Dynamic strength Failure pattern Rock with single planar loading rate Angle of load applied
下载PDF
THREE-DIMENSIONAL ELLIPTIC CRACK UNDER IMPACT LOADING 被引量:4
3
作者 Sun Zhufeng Wu Xiangfa Fan Tianyou 《Acta Mechanica Solida Sinica》 SCIE EI 2001年第4期312-316,共5页
The dynamic stress intensity factor of a three-dimensionalelliptic crack under impact loading is determined with the finiteelement method. The computation results can take into account theinfluence of time and the rat... The dynamic stress intensity factor of a three-dimensionalelliptic crack under impact loading is determined with the finiteelement method. The computation results can take into account theinfluence of time and the ratio of the wave speeds on the stressintensity factor. The present method is suitable not only forthree-dimensional dynamic crack, but also for three-dimensionaldynamic contact. 展开更多
关键词 dynamic loading three-dimensional elliptic crack finite element dynamicstress intensity factor
下载PDF
Integration system research and development for three-dimensional laser scanning information visualization in goaf 被引量:1
4
作者 罗周全 黄俊杰 +2 位作者 罗贞焱 汪伟 秦亚光 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第7期1985-1994,共10页
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo... An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable. 展开更多
关键词 GOAF laser scanning visualization integration system 1 Introduction The goaf formed through underground mining of mineral resources is one of the main disaster sources threatening mine safety production [1 2]. Effective implementation of goaf detection and accurate acquisition of its spatial characteristics including the three-dimensional morphology the spatial position as well as the actual boundary and volume are important basis to analyze predict and control disasters caused by goaf. In recent years three-dimensional laser scanning technology has been effectively applied in goaf detection [3 4]. Large quantities of point cloud data that are acquired for goaf by means of the three-dimensional laser scanning system are processed relying on relevant engineering software to generate a three-dimensional model for goaf. Then a general modeling analysis and processing instrument are introduced to perform subsequent three-dimensional analysis and calculation [5 6]. Moreover related development is also carried out in fields such as three-dimensional detection and visualization of hazardous goaf detection and analysis of unstable failures in goaf extraction boundary acquisition in stope visualized computation of damage index aided design for pillar recovery and three-dimensional detection
下载PDF
Investigation of control effects of end-wall selfadaptive jet on three-dimensional corner separation of a highly loaded compressor cascade
5
作者 Hejian WANG Bo LIU +2 位作者 Xiaochen MAO Botao ZHANG Zonghao YANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第6期109-126,共18页
To overcome the limitations posed by three-dimensional corner separation,this paper proposes a novel flow control technology known as passive End-Wall(EW)self-adaptive jet.Two single EW slotted schemes(EWS1 and EWS2),... To overcome the limitations posed by three-dimensional corner separation,this paper proposes a novel flow control technology known as passive End-Wall(EW)self-adaptive jet.Two single EW slotted schemes(EWS1 and EWS2),alongside a combined(COM)scheme featuring double EW slots,were investigated.The results reveal that the EW slot,driven by pressure differentials between the pressure and suction sides,can generate an adaptive jet with escalating velocity as the operational load increases.This high-speed jet effectively re-excites the local low-energy fluid,thereby mitigating the corner separation.Notably,the EWS1 slot,positioned near the blade leading edge,exhibits relatively low jet velocities at negative incidence angles,causing jet separation and exacerbating the corner separation.Besides,the EWS2 slot is close to the blade trailing edge,resulting in massive low-energy fluid accumulating and separating before the slot outlet at positive incidence angles.In contrast,the COM scheme emerges as the most effective solution for comprehensive corner separation control.It can significantly reduce the total pressure loss and improve the static pressure coefficient for the ORI blade at 0°-4° incidence angles,while causing minimal negative impact on the aerodynamic performance at negative incidence angles.Therefore,the corner stall is delayed,and the available incidence angle range is broadened from -10°--2°to -10°-4°.This holds substantial promise for advancing the aerodynamic performance,operational stability,and load capacity of future highly loaded compressors. 展开更多
关键词 three-dimensional corner separation End-wall adaptive jet Total pressure loss Highly loaded compressor cascade Compressors
原文传递
Effect of applied load on transition behavior of wear mechanism in Cu-15Ni-8Sn alloy under oil lubrication 被引量:4
6
作者 张世忠 甘雪萍 +3 位作者 成金娟 姜业欣 李周 周科朝 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第8期1754-1761,共8页
Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly... Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly from 1.7×10^(-7) to 9.8× 10^(-7) mm^3/mm under the load lower than 300 N, and then increased dramatically to the climax of 216×10^(-7) mm^3/mm under the load over 300 N, which indicated the transition of wear mechanism with the increase of applied load. The wear mechanism mainly was plastic deformation and abrasive wear under the load less than 300 N. As the applied load was more than 300 N, the wear mechanism of Cu-15Ni-8Sn alloy primarily was delamination wear. Besides, the transition can also be confirmed from the different morphologies of worn surface, subsurface and wear debris. It is distinctly indicated that the appearance of flaky debris at the applied load over 300 N may be a critical point for the change of wear mechanism. 展开更多
关键词 Cu-15Ni-8Sn alloy wear mechanism applied load oil lubrication
下载PDF
Three-dimensional consolidation deformation analysis of porous layered soft soils considering asymmetric effects 被引量:1
7
作者 张治国 黄茂松 王卫东 《Journal of Central South University》 SCIE EI CAS 2014年第9期3639-3647,共9页
Long-term settlements for underground structures, such as tunnels and pipelines, are generally observed after the completion of construction in soft clay. The soil consolidation characteristic has great influences on ... Long-term settlements for underground structures, such as tunnels and pipelines, are generally observed after the completion of construction in soft clay. The soil consolidation characteristic has great influences on the long-term deformation for underground structures. A three-dimensional consolidation analysis method under the asymmetric loads is developed for porous layered soil based on Biot's classical theory. Time-displacement effects can be fully considered in this work and the analytical solutions are obtained by the state space approach in the Cartesian coordinate. The Laplace and double Fourier integral transform are applied to the state variables in order to reduce the partial differential equations into algebraic differential equations and easily obtain the state space solution. Starting from the governing equations of saturated porous soil, the basic relationship of state space variables is established between the ground surface and the arbitrary depth in the integral transform domain. Based on the continuity conditions and boundary conditions of the multi-layered pore soil model, the multi-layered pore half-space solutions are obtained by means of the transfer matrix method and the inverse integral transforms. The accuracy of proposed method is demonstrated with existing classical solutions. The results indicate that the porous homogenous soils as well as the porous non-homogenous layered soils can be considered in this proposed method. When the consolidation time factor is 0.01, the value of immediate consolidation settlement coefficient calculated by the weighted homogenous solution is 27.4% bigger than the one calculated by the non-homogeneity solution. When the consolidation time factor is 0.05, the value of excess pore water pressure for the weighted homogenous solution is 27.2% bigger than the one for the non-homogeneity solution. It is shown that the material non-homogeneity has a great influence on the long-term settlements and the dissipation process of excess pore water pressure. 展开更多
关键词 three-dimensional consolidation deformation porous layered soils asymmetric loads long-term deformation prediction transfer matrix method
下载PDF
Autologous nerve graft repair of different degrees of sciatic nerve defect:stress and displacement at the anastomosis in a three-dimensional finite element simulation model 被引量:1
8
作者 Cheng-dong Piao Kun Yang +1 位作者 Peng Li Min Luo 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第5期804-807,共4页
In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the mag- nitude of tensile forces at the anastomosis affects its response to physiological stress and the ultimate success of the ... In the repair of peripheral nerve injury using autologous or synthetic nerve grafting, the mag- nitude of tensile forces at the anastomosis affects its response to physiological stress and the ultimate success of the treatment. One-dimensional stretching is commonly used to measure changes in tensile stress and strain; however, the accuracy of this simple method is limited. There- fore, in the present study, we established three-dimensional finite element models of sciatic nerve defects repaired by autologous nerve grafts. Using PRO E 5.0 finite element simulation software, we calculated the maximum stress and displacement of an anastomosis under a 5 N load in 10-, 20-, 30-, 40-mm long autologous nerve grafts. We found that maximum displacement increased with graft length, consistent with specimen force. These findings indicate that three-dimensional finite element simulation is a feasible method for analyzing stress and displacement at the anas- tomosis after autologous nerve grafting. 展开更多
关键词 nerve regeneration sciatic nerve injury autologous nerve grafting epineurial suturing three-dimensional finite element models load stress DISPLACEMENT neural regeneration
下载PDF
Combined load bearing capacity of rigid piles embedded in a crossanisotropic clay deposit using 3D finite element lower bound 被引量:1
9
作者 Ardavan Izadi Reza Jamshidi Chenari 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第3期717-737,共21页
In this study,an iterative-based three-dimensional finite element lower bound in association with the second-order cone programming method is adopted to evaluate the limit load of a single pile embedded in cross-aniso... In this study,an iterative-based three-dimensional finite element lower bound in association with the second-order cone programming method is adopted to evaluate the limit load of a single pile embedded in cross-anisotropic soils under general loading condition.The lower bound solutions of the pile embedded in an anisotropic soil deposit can be found by formulating the element equilibrium,equilibrium of shear and normal stresses along discontinuities,boundary conditions,yield function,and optimizing the objective function through the second-order cone programming method in conjunction with an iterative-based update procedure.A general loading condition is considered to profile the expansion of the safe load in the vertical-horizontal-moment(V-H-M)space.The results of this study are compared and validated against three different cases including an isotropic lateral loading,anisotropic end bearing capacity,and a pile embedded in an isotropic soil deposit under general loading condition.A parametric study is conducted to evaluate the impact of different influencing factors.It was found that the effect of anisotropy on the variation of lateral limit load of a single pile is more pronounced than the corresponding vertical and bending moment limit loads,whereas the interface properties have more significant effects on the vertical and bending moment limit loads in comparison to the lateral limit load. 展开更多
关键词 Rigid pile Cross-anisotropy CLAY Combined loading three-dimensional finite element lower BOUND
下载PDF
Morphological evolution and flow conduction characteristics of fracture channels in fractured sandstone under cyclic loading and unloading 被引量:1
10
作者 Quanle Zou Zihan Chen +4 位作者 Jinfei Zhan Chunmei Chen Shikang Gao Fanjie Kong Xiaofeng Xia 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第12期1527-1540,共14页
In coal mining,rock strata are fractured under cyclic loading and unloading to form fracture channels.Fracture channels are the main flow narrows for gas.Therefore,expounding the flow conductivity of fracture channels... In coal mining,rock strata are fractured under cyclic loading and unloading to form fracture channels.Fracture channels are the main flow narrows for gas.Therefore,expounding the flow conductivity of fracture channels in rocks on fluids is significant for gas flow in rock strata.In this regard,graded incremental cyclic loading and unloading experiments were conducted on sandstones with different initial stress levels.Then,the three-dimensional models for fracture channels in sandstones were established.Finally,the fracture channel percentages were used to reflect the flow conductivity of fracture channels.The study revealed how the particle size distribution of fractured sandstone affects the formation and expansion of fracture channels.It was found that a smaller proportion of large blocks and a higher proportion of small blocks after sandstone fails contribute more to the formation of fracture channels.The proportion of fracture channels in fractured rock can indicate the flow conductivity of those channels.When the proportion of fracture channels varies gently,fluids flow evenly through those channels.However,if the proportion of fracture channels varies significantly,it can greatly affect the flow rate of fluids.The research results contribute to revealing the morphological evolution and flow conductivity of fracture channels in sandstone and then provide a theoretical basis for clarifying the gas flow pattern in the rock strata of coal mines. 展开更多
关键词 CT imaging Flow conductivity three-dimensional reconstruction Proportion of fracture channels Cyclic loading and unloading
下载PDF
THE 3-D STRESS INTENSITY FACTOR FOR A HALF PLANE CRACK IN A TRANSVERSELY ISOTROPIC SOLID DUE TO THE MOTION OF LOADS ON THE CRACK FACES
11
作者 赵晓华 谢慧才 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1999年第3期265-274,共10页
Three-dimensional analysis of a half plane crack in a transversely isotropic solid is performed. The crack is subjected to a pair of normal point loads moving in a direction perpendicular to the crack edge on its face... Three-dimensional analysis of a half plane crack in a transversely isotropic solid is performed. The crack is subjected to a pair of normal point loads moving in a direction perpendicular to the crack edge on its faces. Transform methods are used to reduce the boundary value problem to a single integral equation that can be solved by the Wiener-Hopf technique. The Cagniard-de Hoop method is employed to invert the transforms. An exact expression is derived for the mode I stress intensity factor as a function of time and position along the crack edge. Some features of the solution are discussed through numerical results. 展开更多
关键词 three-dimensional moving load transverse isotropy half plane crack stress intensity factor
下载PDF
CONVOLUTION OF THE IMPACT THREE-DIMENSIONAL ELASTO-DYNAMICS AND DYNAMIC STRESS INTENSITY FACTOR FOR AN ELLIPTIC CRACK
12
作者 孙竹凤 范天佑 吴祥法 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2002年第3期302-308,共7页
This paper presents a formulation for three-dimensional elasto-dynamics with an elliptic crack based on the Laplace and Fourier transforms and the convolution theorem. The dynamic stress intensity factor for the crack... This paper presents a formulation for three-dimensional elasto-dynamics with an elliptic crack based on the Laplace and Fourier transforms and the convolution theorem. The dynamic stress intensity factor for the crack is determined by solving a Fredholm integral equation of the first kind. The results of this paper are very close to those given by the two-dimensional dual integral equation method. 展开更多
关键词 dynamic loading three-dimensional elliptic crack dynamic stress intensity factor
下载PDF
Three-Dimensional Thermal-Stress Analysis of Semi-infinite Transversely Isotropic Composites
13
作者 TOKOVYY Yuriy BOIKO Dmytro GAO Cunfa 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第1期18-28,共11页
By making use of the direct integration method,an exact analysis of the general three-dimensional thermoelasticity problem is performed for the case of a transversely isotropic homogeneous half-space subject to local ... By making use of the direct integration method,an exact analysis of the general three-dimensional thermoelasticity problem is performed for the case of a transversely isotropic homogeneous half-space subject to local thermal and force loadings.The material plane of isotropy is assumed to be parallel to the limiting surface of the halfspace.By reducing the original thermoelasticity equations to the governing ones for individual stress-tensor components,the effect of material anisotropy in the stress field is analyzed with regard to the feasibility requirement,i.e.,the finiteness of the stress field at a distance from the disturbed area.As a result,the solution is constructed in the form of explicit analytical dependencies on the force and thermal loadings for various kinds of transversely isotropic materials and agrees with the basic principles of the continua mechanics.The solution can be efficiently used as a benchmark one for the direct computation of temperature and thermal stresses in transversely isotropic semi-infinite domains,as well as for the verification of solutions constructed by different means. 展开更多
关键词 three-dimensional problem analytical solution transversely isotropic composites semi-infinite model force and thermal loadings finite stress distributions
下载PDF
Researches on Cartographic Database-Based Interactive Three-Dimensional Topographic Map
14
作者 JiangWenping XiDaping 《Journal of China University of Geosciences》 SCIE CSCD 2003年第4期374-380,共7页
With the development of computer graphics, the three-dimensional (3D) visualization brings new technological revolution to the traditional cartography. Therefore, the topographic 3D-map emerges to adapt to this techno... With the development of computer graphics, the three-dimensional (3D) visualization brings new technological revolution to the traditional cartography. Therefore, the topographic 3D-map emerges to adapt to this technological revolution, and the applications of topographic 3D-map are spread rapidly to other relevant fields due to its incomparable advantage. The researches on digital map and the construction of map database offer strong technical support and abundant data source for this new technology, so the research and development of topographic 3D-map will receive greater concern. The basic data of the topographic 3D-map are rooted mainly in digital map and its basic model is derived from digital elevation model (DEM) and 3D-models of other DEM-based geographic features. In view of the potential enormous data and the complexity of geographic features, the dynamic representation of geographic information becomes the focus of the research of topographic 3D-map and also the prerequisite condition of 3D query and analysis. In addition to the equipment of hardware that are restraining, to a certain extent, the 3D representation, the data organization structure of geographic information will be the core problem of research on 3D-map. Level of detail (LOD), space partitioning, dynamic object loading (DOL) and object culling are core technologies of the dynamic 3D representation. The object- selection, attribute-query and model-editing are important functions and interaction tools for users with 3D-maps provided by topographic 3D-map system, all of which are based on the data structure of the 3D-model. This paper discusses the basic theories, concepts and cardinal principles of topographic 3D-map, expounds the basic way to organize the scene hierarchy of topographic 3D-map based on the node mechanism and studies the dynamic representation technologies of topographic 3D-map based on LOD, space partitioning, DOL and object culling. Moreover, such interactive operation functions are explored, in this paper, as spatial query, scene editing and management of topographic 3D-map. Finally, this paper describes briefly the applications of topographic 3D-map in its related fields. 展开更多
关键词 three-dimensional (3D) visualization topographic 3D-map level of detail (LOD) space partitioning dynamic object loading (DOL) dynamic representation.
下载PDF
数智化时代“三融合”会计学本科应用型人才培养模式构建
15
作者 张春风 侯婧 《廊坊师范学院学报(自然科学版)》 2024年第2期119-123,128,共6页
目前是以大智移物云区块链为标志的数智化时代发展的重要时期,数智化渗入会计实务工作,为会计学科建设和会计本科人才培养模式带来变革性影响。传统的会计本科人才培养出现如专业教育与思政教育两张皮、培养模式难以满足数智化时代对应... 目前是以大智移物云区块链为标志的数智化时代发展的重要时期,数智化渗入会计实务工作,为会计学科建设和会计本科人才培养模式带来变革性影响。传统的会计本科人才培养出现如专业教育与思政教育两张皮、培养模式难以满足数智化时代对应用型人才的高质量需求等问题,在此背景下,以“思政引领”为导向,大智移物云区块链等“技术载入”为载体“,实践落地”为落脚点,在“思政引领+技术载入+实践落地”三融合的基础上对会计学本科专业培养目标、课程体系、教学模式和保障机制进行重构,以培养满足高质量发展的会计专业复合应用型人才需求。 展开更多
关键词 数智化时代 思政引领 技术载入 实践落地 应用型人才培养
下载PDF
关于源网荷储一体化应用的探究
16
作者 刘涛 韩道强 +2 位作者 胡赣林 赵孟浩 赵鹏鸽 《中国科技纵横》 2024年第4期39-41,共3页
在“双碳”目标背景下,能源生产和应用过程中所产生的用碳排放量都应该有所降低。为加快降低碳排放步伐,不仅要借助先进的科学技术,还需要完善科学有效的能源生产、应用等模式。源网荷储一体化作为统一、高效的能源系统,不仅从根源上提... 在“双碳”目标背景下,能源生产和应用过程中所产生的用碳排放量都应该有所降低。为加快降低碳排放步伐,不仅要借助先进的科学技术,还需要完善科学有效的能源生产、应用等模式。源网荷储一体化作为统一、高效的能源系统,不仅从根源上提高了能源的利用效率,优化了能源资源配置,还实现了对可再生能源的大规模接纳和储能技术的有效利用。基于此,从源网荷储一体化概述入手,分析源网荷储一体化应用时发电侧调节各类电力资源的建设不足、负荷侧调节电力资源的建设不足、协调电力供给与需求的配套设施建设缺乏等问题,并提出相应的解决对策。 展开更多
关键词 能源 源网荷储 一体化 应用
下载PDF
Direct loading of atoms from a macroscopic quadrupole magnetic trap into a microchip trap 被引量:1
17
作者 程俊 张敬芳 +2 位作者 许忻平 张海潮 王育竹 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期315-320,共6页
We demonstrate the direct loading of cold atoms into a microchip 2-mm Z-trap, where the evaporative cooling can be performed efficiently, from a macroscopic quadrupole magnetic trap with a high loading efficiency. The... We demonstrate the direct loading of cold atoms into a microchip 2-mm Z-trap, where the evaporative cooling can be performed efficiently, from a macroscopic quadrupole magnetic trap with a high loading efficiency. The macroscopic quadrupole magnetic trap potential is designed to be moveable by controlling the currents of the two pairs of anti-Helrnholtz coils. The cold atoms are initially prepared in a standard six-beam magneto-optical trap and loaded into the macroscopic quadrupole magnetic trap, and then transported to the atom chip surface by moving the macroscopic trap potential. By means of a three-dimensional absorption imaging system, we are able to optimize the position alignment of the atom cloud in the macroscopic trap and the microchip Z-shaped wire. Consequently, with a proper magnetic transfer scheme, we load the cold atoms into the microchip Z-trap directly and efficiently. The loading efficiency is measured to be about 50%. This approach can be used to generate appropriate ultracold atoms sources, for example, for a magnetically guided atom interferometer based on atom chip. 展开更多
关键词 atom chip three-dimensional absorption imaging direct magnetic loading
下载PDF
Non-Intrusive Load Identification Model Based on 3D Spatial Feature and Convolutional Neural Network 被引量:1
18
作者 Jiangyong Liu Ning Liu +3 位作者 Huina Song Ximeng Liu Xingen Sun Dake Zhang 《Energy and Power Engineering》 2021年第4期30-40,共11页
<div style="text-align:justify;"> Load identification method is one of the major technical difficulties of non-intrusive composite monitoring. Binary V-I trajectory image can reflect the original V-I t... <div style="text-align:justify;"> Load identification method is one of the major technical difficulties of non-intrusive composite monitoring. Binary V-I trajectory image can reflect the original V-I trajectory characteristics to a large extent, so it is widely used in load identification. However, using single binary V-I trajectory feature for load identification has certain limitations. In order to improve the accuracy of load identification, the power feature is added on the basis of the binary V-I trajectory feature in this paper. We change the initial binary V-I trajectory into a new 3D feature by mapping the power feature to the third dimension. In order to reduce the impact of imbalance samples on load identification, the SVM SMOTE algorithm is used to balance the samples. Based on the deep learning method, the convolutional neural network model is used to extract the newly produced 3D feature to achieve load identification in this paper. The results indicate the new 3D feature has better observability and the proposed model has higher identification performance compared with other classification models on the public data set PLAID. </div> 展开更多
关键词 Non-Intrusive load Identification Binary V-I Trajectory Feature three-dimensional Feature Convolutional Neural Network Deep Learning
下载PDF
AUV Load Separation Motion with Constraint of Anchor Chain
19
作者 邵成 宋保维 +2 位作者 杜晓旭 王鹏 李家旺 《Defence Technology(防务技术)》 SCIE EI CAS 2009年第1期20-23,共4页
Motion equations of AUV(autonomous underwater vehicle) load separation with the constraint of anchor chain is derived.Based on proper engineering assumptions for anchor chain,system viewpoint is used to found the moti... Motion equations of AUV(autonomous underwater vehicle) load separation with the constraint of anchor chain is derived.Based on proper engineering assumptions for anchor chain,system viewpoint is used to found the motion equations,and the D'Alembert principle is used to eliminate the constraint force of anchor chain.Based on the equations,the motion simulation is carried out to a certain AUV,which reflects the actual condition,and is used for the reference of resrarching AUV load separation motion with the constraint of anchor chain. 展开更多
关键词 自治水下机器人 分离运动 锚链 运动负荷 运动方程 AUV 运动仿真
下载PDF
Elastodynamic stress intensity factor due to three-dimensional concentrated transient loading on the faces of a crack 被引量:1
20
作者 赵晓华 《Science China(Technological Sciences)》 SCIE EI CAS 1997年第3期269-278,共10页
The dynamic stress intensity factor for a semi-infinite crack in an otherwise unbounded elastic body is analyzed The crack is subjected to a pair of suddenly applied point loads on its faces at a distance l away from ... The dynamic stress intensity factor for a semi-infinite crack in an otherwise unbounded elastic body is analyzed The crack is subjected to a pair of suddenly applied point loads on its faces at a distance l away from the crack tip The solution of the problem is obtained by superposition of the solutions of two simpler problems. The first of these problems is Lamb' s problem, while the second problem considers a half space with its surface subjected to the negative of the normal displacement induced by Lamb's problem in the range x>0. The latter is solved by means of integral transforms together with the application of Weiner-Hopf technique and Cagniard-de Hoop method. An exact expression is derived for the mode I stress intensity factor as a function of time for any point along the crack edge. Some features of the solution are discussed. 展开更多
关键词 three-dimensional TRANSIENT loadING SEMI-INFINITE CRACK stress intensity factor.
原文传递
上一页 1 2 7 下一页 到第
使用帮助 返回顶部