期刊文献+
共找到3,997篇文章
< 1 2 200 >
每页显示 20 50 100
Research on the path of effective management of participation in joint-venture railway companies by China railway group
1
作者 Shaoni Zhou Zhitian Zhou Chenxia Kang 《Railway Sciences》 2024年第4期530-539,共10页
Purpose-Following the regional restructuring,the number of joint-venture railway companies in which the Group participates has significantly increased.This paper aims to explore the challenges faced by China Railway G... Purpose-Following the regional restructuring,the number of joint-venture railway companies in which the Group participates has significantly increased.This paper aims to explore the challenges faced by China Railway Group in managing participation in joint-venture railway companies.The study seeks to propose specific approaches to ensure the effective management of these companies,thereby maximizing the benefits of the regional restructuring and supporting the development of a strong transportation country and a modern infrastructure system.Design/methodology/approach-Based on the change in the shareholding relationship between China Railway Group and the joint-venture railway companies,and considering the current situation of the regional restructuring of these companies,as well as the insights from existing literature and typical case studies,this paper proposes some specific paths for effective management of joint-stock railway companies which China Railway Group participated in.Findings-The problems in participation management are the unclear dual leadership role of the party committee,the lack of discourse power,the lack of synergy between shareholders,the increasing risk of sustainable operation of the loss-making companies and the role of dispatched personnel is not fully played.Based on the theories,combined with the existing research and practical cases,the paper proposed specific approaches,such as perfecting top-level system design,maintaining the discourse power,carrying out differentiated management,arranging personnel rationally,arranging shareholders synergy,and innovating methods to provide references for China Railway Group’s subsequent management of joint venture railway companies.Originality/value-This paper contributes to the existing literature by providing a comprehensive analysis of the challenges faced by China Railway Group in managing participation in joint-venture railway companies following the regional restructuring.The study offers novel insights and practical recommendations for addressing these challenges.The findings can serve as valuable references for China Railway Group’s subsequent management of joint-venture railway companies which participated in,as well as for other stateowned enterprises facing similar challenges in managing their joint ventures. 展开更多
关键词 China railway group joint venture railway companies participated relationship Effective management
下载PDF
Statistical Analysis of Students’Learning Effectiveness in Online Courses Offered by British Partners in China-UK Joint Education Program
2
作者 Liangquan He Donglei He 《Journal of Contemporary Educational Research》 2024年第10期90-98,共9页
In the context of internationalization,China-UK Joint Education Programs are receiving increasing attention from universities.Based on the difficulties faced in China-UK Joint Education Program,this paper adopts a que... In the context of internationalization,China-UK Joint Education Programs are receiving increasing attention from universities.Based on the difficulties faced in China-UK Joint Education Program,this paper adopts a questionnaire survey method to study the learning effectiveness of students majoring in digital media technology in the China-UK Joint Education Program at Guangxi University of Finance and Economics,focusing on four aspects:learning materials,learning content,teacher conditions,and student learning outcomes.The research analysis in this paper not only provides strong support for the construction of China-UK Joint Education Program but also offers references for other China-UK Joint Education Programs. 展开更多
关键词 China-UK joint Education Program Online courses Learning effectiveness
下载PDF
Characterisation of wear particles from biomedical carbon/carbon composites with different preforms in hip joint simulator 被引量:4
3
作者 张磊磊 李贺军 +5 位作者 张守阳 卢锦花 张雨雷 赵雪妮 谷彩阁 曾燮榕 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2562-2568,共7页
A hip joint simulator was employed to predict the clinical wear behaviour of carbon/carbon (C/C) composites with needled carbon cloth preform and carbon felt preform. Wear particles generated from the two kinds of C... A hip joint simulator was employed to predict the clinical wear behaviour of carbon/carbon (C/C) composites with needled carbon cloth preform and carbon felt preform. Wear particles generated from the two kinds of C/C composites were isolated and characterised by the size distribution and morphology. The evolvement of wear particles in the hip joint simulator was proposed. The results show that the wear particles from two kinds of C/C composites have a size ranging from submicron to tens of micrometers. The wear particles have various morphologies including broken fiber, fragment fiber, slice pyrolytic carbon and spherical pyrolytic carbon. C/C composites with needled carbon cloth preforms have larger size range and more broken fiber particles and slice pyrolytic carbon particles in comparison with C/C composites with carbon felt preforms. The evolvement of pyrolytic carbon particles is caused by surface regularization, whereas, the evolvement of carbon fiber particles is related to stress direction in the hip joint simulator. 展开更多
关键词 carbon/carbon composites particle shape BIO-TRIBOLOGY hip joint
下载PDF
Crack initiation stress and strain of jointed rock containing multi-cracks under uniaxial compressive loading: A particle flow code approach 被引量:16
4
作者 范祥 KULATILAKE P H S W +1 位作者 陈新 曹平 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第2期638-645,共8页
The ratio of crack initiation stress to the uniaxial compressive strength(SCI,B/SUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A... The ratio of crack initiation stress to the uniaxial compressive strength(SCI,B/SUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A/SSSS) were studied by performing numerical stress analysis on blocks having multi flaws at close spacing's under uniaxial loading using PFC3 D. The following findings are obtained: SCI,B/SUC,B has an average value of about 0.5 with a variability of ± 0.1. This range agrees quite well with the values obtained by former research. For joint inclination angle, β=90°,B,UCB,CI,A,A/SSSS is found to be around 0.48 irrespective of the value of joint continuity factor, k. No particular relation is found betweenB,UCB,CI,A,A/SSSS and β; however, the average B,UCB,CI,A,A/SSSS seems to slightly decrease with increasing k. The variability ofB,UCB,CI,A,A/SSSS is found to increase with k.Based on the cases studied in this work,B,UCB,CI,A,A/SSSS ranges between 0.3 and 0.5. This range is quite close to the range of 0.4to 0.6 obtained for SCI,B/SUC,B. The highest variability of ± 0.12 forB,UCB,CI,A,A/SSSS is obtained for k=0.8. For the remaining k values the variability ofB,UCB,CI,A,A/SSSS can be expressed within ± 0.05. This finding is very similar to the finding obtained for the variability of SCI,B/SUC,B. 展开更多
关键词 jointed rock multi flaws uniaxial loading PFC3D model crack initiation stress(SCI B) axial strain at crack initiation
下载PDF
Particle flow study on strength and meso-mechanism of Brazilian splitting test for jointed rock mass 被引量:19
5
作者 Sheng-Qi Yang Yan-Hua Huang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第4期547-558,共12页
A discrete element method (DEM) called particle flow code (PFC2D) was used to construct a model for Brazilian disc splitting test in the present study. Based on the experimental results of intact Brazilian disc of... A discrete element method (DEM) called particle flow code (PFC2D) was used to construct a model for Brazilian disc splitting test in the present study. Based on the experimental results of intact Brazilian disc of rock-like material, a set of micro-parameters in PFC2D that reflected the macro-mechanical behavior of rock-like materials were obtained. And then PFC2D was used to simulate Brazilian splitting test for jointed rock mass specimens and specimen containing a central straight notch. The effect of joint angle and notch angle on the tensile strength and failure mode of jointed rock specimens was detailed analyzed. In order to reveal the meso-mechanical mechanism of crack coalescence, displacement trend lines were applied to analyze the displacement evolution during the crack initiation and propagation. The investigated conclusions can be described as follows. (1) The tensile strength of jointed rock mass disc specimen is dependent to the joint angle. As the joint angle increases, the tensile strength of jointed rock specimen takes on a nonlinear variance. (2) The tensile strength of jointed rock mass disc specimen containing a central straight notch distributes as a function of both joint angle and notch angle. (3) Three major failure modes, i.e., pure tensile failure, shear failure and mixed tension and shear failure mode are observed in jointed rock mass disc specimens under Brazilian test. (4) The notch angle roles on crack initiation and and joint angle play important propagation characteristics of jointed rock mass disc specimen containing a central straight notch under Brazilian test. 展开更多
关键词 jointed rock mass Brazilian splitting test. Ten-sile strength· Failure mode PFC2D
下载PDF
Joint optimization of maintenance inspection and spare provisioning for aircraft deteriorating parts 被引量:4
6
作者 Jing Cai Xin Li Xi Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第6期1133-1140,共8页
With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircr... With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircraft operational cost, is receiving increasing attention. In order to optimize the inspection interval, maintenance decision and spare provisioning together for aircraft deteriorating parts, firstly, a joint inventory management strategy is presented, then, a joint optimization of maintenance inspection and spare provisioning for aircraft parts subject to the Wiener degradation process is proposed based on the strategy.Secondly, a combination of the genetic algorithm(GA) and the Monte Carol method is developed to minimize the total cost rate.Finally, a case study is conducted and the proposed joint optimization model is compared with the existing optimization model and the airline real case. The results demonstrate that the proposed model is more beneficial and effective. In addition, the sensitivity analysis of the proposed model shows that the lead time has higher influence on the optimal results than the urgent order cost and the corrective maintenance cost, which is consistent with the actual situation of aircraft maintenance practices and inventory management. 展开更多
关键词 joint optimization maintenance spare provision aircraft part Wiener process
下载PDF
Elastoplastic pipe-soil interaction analyses of partially-supported jointed water mains 被引量:4
7
作者 Yu SHAO Tu-qiao ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第11期1497-1506,共10页
Water distribution networks are essential components of water supply systems. The combination of pipe structural deterioration and mechanics leads to the failure of pipelines. A physical model for estimating the pipe ... Water distribution networks are essential components of water supply systems. The combination of pipe structural deterioration and mechanics leads to the failure of pipelines. A physical model for estimating the pipe failure must include both the pipe deterioration model and mechanics model. Winkler pipe-soil interaction (WPSI), an analytical mechanics model developed by Rajani and Tesfamariam (2004), takes external and internal loads, temperature changes, loss of bedding support, and the elastoplastic effect of soil into consideration. Based on the WPSI model, a method to evaluate the elastic and plastic areas was proposed in the present study. An FEM model based on pipe-soil interaction (PSI) element was used to verify the analytical model. Sensitivity analyses indicate that the soft soil, long pipe and high temperature induced the axial plastic deformation more likely, which, however, may not occur in normal scenarios. The soft soil, pipes in small diameters, long unsupported bedding are prone to form flexural plastic area. The results show that the pipes subjected to the same loads have smaller stresses in the elastoplastic analysis than elastic analysis. The difference, however, is slight. 展开更多
关键词 Elastoplastic soil Winkler pipe-soil interaction (WPSI) jointed water mains
下载PDF
QUICK ASSESSMENT METHODOLOGY FOR RELIABILITY OF SOLDER JOINTS IN BALL GRID ARRAY (BGA) ASSEMBLY——PART Ⅰ: CREEP CONSTITUTIVE RELATION AND FATIGUE MODEL 被引量:3
8
作者 史训清 王志平 +2 位作者 John HL Pang 张学仁 聂景旭 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2002年第3期274-287,共14页
In this study, a new unified creep constitutive relation and a mod- ified energy-based fatigue model have been established respectively to describe the creep flow and predict the fatigue life of Sn-Pb solders. It is f... In this study, a new unified creep constitutive relation and a mod- ified energy-based fatigue model have been established respectively to describe the creep flow and predict the fatigue life of Sn-Pb solders. It is found that the relation successfully elucidates the creep mechanism related to current constitutive relations. The model can be used to describe the temperature and frequency dependent low cycle fatigue behavior of the solder. The relation and the model are further employed in part Ⅱ to develop the numerical simulation approach for the long-term reliability assessment of the plastic ball grid array (BGA) assembly. 展开更多
关键词 dislocation controlled creep flow creep-fatigue interaction constitutive relation life prediction model solder joint reliability
下载PDF
A novel method for geometric quality assurance of rock joint replicas in direct shear testing-Part 1:Derivation of quality assurance parameters and geometric reproducibility 被引量:1
9
作者 J.Larsson F.Johansson +3 位作者 D.Mas Ivars E.Johnson M.Flansbjer N.W.Portal 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第9期2193-2208,共16页
Since each rock joint is unique by nature,the utilization of replicas in direct shear testing is required to carry out experimental parameter studies.However,information about the ability of the replicas to simulate t... Since each rock joint is unique by nature,the utilization of replicas in direct shear testing is required to carry out experimental parameter studies.However,information about the ability of the replicas to simulate the shear mechanical behavior of the rock joint and their dispersion in direct shear testing is lacking.With the aim to facilitate generation of high-quality direct shear test data from replicas,a novel component in the testing procedure is introduced by presenting two parameters for geometric quality assurance.The parameters are derived from surface comparisons of three-dimensional(3D)scanning data of the rock joint and its replicas.The first parameter,smf,captures morphological deviations between the replica and the rock joint surfaces.smf is derived as the standard deviation of the deviations between the coordinate points of the replica and the rock joint.Four sources of errors introduced in the replica manufacturing process employed in this study could be identified.These errors could be minimized,yielding replicas with smf0.06 mm.The second parameter is a vector,VHp100,which describes deviations with respect to the shear direction.It is the projection of the 100 mm long normal vector of the best-fit plane of the replica joint surface to the corresponding plane of the rock joint.VHp100was found to be less than or equal to 0.36 mm in this study.Application of these two geometric quality assurance parameters demonstrates that it is possible to manufacture replicas with high geometric similarity to the rock joint.In a subsequent paper(part 2),smf and VHp100 are incorporated in a novel quality assurance method,in which the parameters shall be evaluated prior to direct shear testing.Replicas having parameter values below established thresholds shall have a known and narrow dispersion and imitate the shear mechanical behavior of the rock joint. 展开更多
关键词 Three-dimensional(3D)scanning Geometric reproducibility Geometric quality assurance Replicas Rock joint Surface comparisons
下载PDF
Seismic Behaviour of Beam-Column Joints of Precast and Partial Steel Reinforced Concrete 被引量:1
10
作者 Wanpeng Cheng Licheng Wang +1 位作者 Yupu Song Jun Wang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第2期108-117,共10页
A beam-column joint of precast and partial steel reinforced concrete( PPSRC) is proposed for precast reinforced concrete frames. The PPSRC consists of partial steel and reinforced concrete. The partial steel is locate... A beam-column joint of precast and partial steel reinforced concrete( PPSRC) is proposed for precast reinforced concrete frames. The PPSRC consists of partial steel and reinforced concrete. The partial steel is located in the core joint region and the connections between concrete members. This paper presents an experimental study of a series of PPSRC specimens. These specimens are tested under low cyclic loading.Experimental results demonstrate that the bearing capacity of the PPSRC specimens is 3 times that of the ordinary reinforced concrete( RC) beam-column joints. The strength and stiffness degradation rates are slower compared with that of the RC beam-column joints. In addition,the strength of the core joint region and the connections is higher than other parts of the PPSRC specimens. Beam failure occurs firstly for the PPSRC specimens,followed by column failure and connections failure. The failure of the core joint region occurs finally.Test results show that the seismic performance of the PPSRC is better than that of the ordinary RC beam-column joints. 展开更多
关键词 preeast and partial steel reinforced concrete (PPSRC) beam-column joints low cyclic test hysteretic curve degradations of strength and stiffness DUCTILITY
下载PDF
Stress Analysis of Bolted Joints Part II. Contact and Slip Analysis of a Four Bolt Joint 被引量:1
11
作者 László Molnár Károly Váradi +1 位作者 János Holubán Andor Tamási 《Modern Mechanical Engineering》 2014年第1期46-55,共10页
For up-to-date bolted joints, first of all in vehicles, high strength bolts of 10.9 or even 12.9 are used, which are preloaded up to 90% or even 100% of the yield strength. The primary aim of this high degree utilizat... For up-to-date bolted joints, first of all in vehicles, high strength bolts of 10.9 or even 12.9 are used, which are preloaded up to 90% or even 100% of the yield strength. The primary aim of this high degree utilization is the weight reduction. For the analytic dimensioning of bolted joints, the VDI 2230 Richtlinien German standard [1] provides support. However, the analytic model can mostly consider the true structural characteristics only in a limited way. The analytic modeling is especially uncertain in case of multiple bolted joints when the load distribution among the bolts depends reasonably upon the elastic deformation of the participating elements in the joints over the geometry of the bolted joint. The first part of this paper deals with the problems of numerical modeling and stress analysis, respectively specifying the analytic dimensioning procedure by applying elastic or rather elastic-plastic material law. The error magnitude in bolted joint calculation was examined in case of omitting the existing threaded connection—between the bolt and the nut—in order to simplify the model. The second part of the paper deals with the dimensioning of stands and cantilevers’ multi-bolt fixing problems, first of all, with the load distribution among the bolts keeping in view the analysis of the local slipping relations. For demonstrating the above technique, an elaborated numeric procedure is presented for a four-bolted cantilever, having bolted joints pre-tightened to the yield strength. 展开更多
关键词 BOLTED jointS Numerical Modeling Stress ANALYSIS
下载PDF
Cyclic shear behavior of en-echelon joints under constant normal stiffness conditions 被引量:1
12
作者 Bin Wang Yujing Jiang +3 位作者 Qiangyong Zhang Hongbin Chen Richeng Liu Yuanchao Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3419-3436,共18页
To reveal the mechanism of shear failure of en-echelon joints under cyclic loading,such as during earthquakes,we conducted a series of cyclic shear tests of en-echelon joints under constant normal stiffness(CNS)condit... To reveal the mechanism of shear failure of en-echelon joints under cyclic loading,such as during earthquakes,we conducted a series of cyclic shear tests of en-echelon joints under constant normal stiffness(CNS)conditions.We analyzed the evolution of shear stress,normal stress,stress path,dilatancy characteristics,and friction coefficient and revealed the failure mechanisms of en-echelon joints at different angles.The results show that the cyclic shear behavior of the en-echelon joints is closely related to the joint angle,with the shear strength at a positive angle exceeding that at a negative angle during shear cycles.As the number of cycles increases,the shear strength decreases rapidly,and the difference between the varying angles gradually decreases.Dilation occurs in the early shear cycles(1 and 2),while contraction is the main feature in later cycles(310).The friction coefficient decreases with the number of cycles and exhibits a more significant sensitivity to joint angles than shear cycles.The joint angle determines the asperities on the rupture surfaces and the block size,and thus determines the subsequent shear failure mode(block crushing and asperity degradation).At positive angles,block size is more greater and asperities on the rupture surface are smaller than at nonpositive angles.Therefore,the cyclic shear behavior is controlled by block crushing at positive angles and asperity degradation at negative angles. 展开更多
关键词 En-echelon joint Cyclic shear tests Shear stress Normal displacement Constant normal stiffness(CNS)
下载PDF
Experimental and simulation research on hollow AZ31 magnesium alloy three-channel joint by hot extrusion forming with sand mandrel 被引量:1
13
作者 Shi Shengnan Wang Hongyu +4 位作者 Teng Fei Jiang Lei Sun Juncai Sun Jie Zhang Shunhu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期98-109,共12页
Magnesium alloy is one of the lightest metal structural materials.The weight is further reduced through the hollow structure.However,the hollow structure is easily damaged during processing.In order to maintain the ho... Magnesium alloy is one of the lightest metal structural materials.The weight is further reduced through the hollow structure.However,the hollow structure is easily damaged during processing.In order to maintain the hollow structure and to transfer the stresses during the high temperature deformation,the sand mandrel is proposed.In this paper,the hollow AZ31 magnesium alloy three-channel joint is studied by hot extrusion forming.Sand as one of solid granule medium is used to fill the hollow magnesium alloy.The extrusion temperatures are 230℃ and 300℃,respectively.The process parameters(die angle,temperature,bottom thickness,sidewall thickness,edge-to-middle ratio in bottom,bottom shape)of the hollow magnesium alloy are analyzed based on the results of experiments and the finite element method.The results are shown that the formability of the hollow magnesium alloy will be much better when the ratio of sidewall thickness to the bottom thickness is 1:1.5.Also when edge-to-middle ratio in bottom is about 1:1.5,a better forming product can be received.The best bottom shape in these experiments will be convex based on the forming results.The grain will be refined obviously after the extrusion.Also the microstructures will be shown as streamlines.And these lines will be well agreement with the mold in the corner. 展开更多
关键词 AZ31 magnesium alloy Three-channel joint SAND Experiments and the finite element Die angle
下载PDF
Perfect Biparticle Teleportation by Using Multi-particle Quantum Channel with Joint Measurement
14
作者 NIE Jing LI Chong YI Xue-Xi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第6期1491-1494,共4页
In this paper, we reinvestigate the faithful quantum teleportation of an arbitrary two-qubit state by a multi-particle channel with multi-particle joint measurements. The relationship between multi-particle quantum ch... In this paper, we reinvestigate the faithful quantum teleportation of an arbitrary two-qubit state by a multi-particle channel with multi-particle joint measurements. The relationship between multi-particle quantum channel and the multi-particle joint measurement bases has been found. In addition, we show how to construct the multi-particle joint measurement bases. 展开更多
关键词 quantum entanglement TELEPORTATION joint measurement
下载PDF
Analysis of the joint detection capability of the SMILE satellite and EISCAT-3D radar 被引量:2
15
作者 JiaoJiao Zhang TianRan Sun +7 位作者 XiZheng Yu DaLin Li Hang Li JiaQi Guo ZongHua Ding Tao Chen Jian Wu Chi Wang 《Earth and Planetary Physics》 EI CSCD 2024年第1期299-306,共8页
The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite is a small magnetosphere–ionosphere link explorer developed cooperatively between China and Europe.It pioneers the use of X-ray imaging technology... The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite is a small magnetosphere–ionosphere link explorer developed cooperatively between China and Europe.It pioneers the use of X-ray imaging technology to perform large-scale imaging of the Earth’s magnetosheath and polar cusp regions.It uses a high-precision ultraviolet imager to image the overall configuration of the aurora and monitor changes in the source of solar wind in real time,using in situ detection instruments to improve human understanding of the relationship between solar activity and changes in the Earth’s magnetic field.The SMILE satellite is scheduled to launch in 2025.The European Incoherent Scatter Sciences Association(EISCAT)-3D radar is a new generation of European incoherent scatter radar constructed by EISCAT and is the most advanced ground-based ionospheric experimental device in the high-latitude polar region.It has multibeam and multidirectional quasi-real-time three-dimensional(3D)imaging capabilities,continuous monitoring and operation capabilities,and multiple-baseline interferometry capabilities.Joint detection by the SMILE satellite and the EISCAT-3D radar is of great significance for revealing the coupling process of the solar wind–magnetosphere–ionosphere.Therefore,we performed an analysis of the joint detection capability of the SMILE satellite and EISCAT-3D,analyzed the period during which the two can perform joint detection,and defined the key scientific problems that can be solved by joint detection.In addition,we developed Web-based software to search for and visualize the joint detection period of the SMILE satellite and EISCAT-3D radar,which lays the foundation for subsequent joint detection experiments and scientific research. 展开更多
关键词 Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite European Incoherent Scatter Sciences Association(EISCAT)-3D radar joint detection
下载PDF
Blood metal concentrations and cardiac structure and function in total joint arthroplasty patients 被引量:1
16
作者 Peter C Brennan Stephanie M Peterson +6 位作者 Thomas J O'Byrne Mariana L Laporta Cody C Wyles Paul J Jannetto Garvan C Kane Maria Vassilaki Hilal Maradit Kremers 《World Journal of Orthopedics》 2024年第8期773-782,共10页
BACKGROUND There is concern regarding potential long-term cardiotoxicity with systemic distribution of metals in total joint arthroplasty(TJA)patients.AIM To determine the association of commonly used implant metals w... BACKGROUND There is concern regarding potential long-term cardiotoxicity with systemic distribution of metals in total joint arthroplasty(TJA)patients.AIM To determine the association of commonly used implant metals with echocardiographic measures in TJA patients.METHODS The study comprised 110 TJA patients who had a recent history of high chromium,cobalt or titanium concentrations.Patients underwent two-dimensional,three-dimensional,Doppler and speckle-strain transthoracic echocardiography and a blood draw to measure metal concentrations.Age and sex-adjusted linear and logistic regression models were used to examine the association of metal concentrations(exposure)with echocardiographic measures(outcome).RESULTS Higher cobalt concentrations were associated with increased left ventricular end-diastolic volume(estimate 5.09;95%CI:0.02-10.17)as well as left atrial and right ventricular dilation,particularly in men but no changes in cardiac function.Higher titanium concentrations were associated with a reduction in left ventricle global longitudinal strain(estimate 0.38;95%CI:0.70 to 0.06)and cardiac index(estimate 0.08;95%CI,-0.15 to-0.01).CONCLUSION Elevated cobalt and titanium concentrations may be associated with structural and functional cardiac changes in some patients.Longitudinal studies are warranted to better understand the systemic effects of metals in TJA patients. 展开更多
关键词 Total joint arthroplasty METAL-ON-METAL CARDIOTOXICITY Heart failure ECHOCARDIOGRAPHY COBALT
下载PDF
Deterministic Joint Remote Preparation of Arbitrary Four-Particle Genuine Entangled State
17
作者 李剑 聂金瑞 +2 位作者 赵培均 李睿凡 邹永忠 《China Communications》 SCIE CSCD 2013年第2期11-18,共8页
A novel deterministic joint remote preparation scheme of arbitrary four-particle genuine entangled state from one sender to either of two receivers is proposed. Two three-particle Green-Horne-Zeilinger (GHZ) states ... A novel deterministic joint remote preparation scheme of arbitrary four-particle genuine entangled state from one sender to either of two receivers is proposed. Two three-particle Green-Horne-Zeilinger (GHZ) states and one four-particle GHZ state are used as the quantum channel. The presented scheme is realized through orthogonal projective mea-surement of the Hadamard transferred basis and recovery operation Ulijk). Some useful and general measurement bases have been con-structed. The classical communication cost of the presented scheme is also calculated. Our analysis confirms the feasibility and validity of the proposed method, and shows that it has a 100% probability of success in preparation of the target quantum state. 展开更多
关键词 joint remote preparation four-particle genuine entangled state projectivemeasurement Hadamard transferred basis
下载PDF
Deterministic hierarchical joint remote state preparation with six-particle partially entangled state
18
作者 Na Chen Bin Yan +2 位作者 Geng Chen Man-Jun Zhang Chang-Xing Pei 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期184-190,共7页
In this paper, we present a novel scheme for hierarchical joint remote state preparation(HJRSP) in a deterministic manner, where two senders can jointly and remotely prepare an arbitrary single-qubit at three receiv... In this paper, we present a novel scheme for hierarchical joint remote state preparation(HJRSP) in a deterministic manner, where two senders can jointly and remotely prepare an arbitrary single-qubit at three receivers' port. A six-particle partially entangled state is pre-shared as the quantum channel. There is a hierarchy among the receivers concerning their powers to reconstruct the target state. Due to various unitary operations and projective measurements, the unit success probability can always be achieved irrespective of the parameters of the pre-shared partially entangled state. 展开更多
关键词 joint remote state preparation hierarchical quantum communication partially entangled state
下载PDF
Static behavior of semi-rigid thin-walled steel-concrete composite beam-to-column joints with bolted partial-depth flush end plate:experimental study
19
作者 郜京峰 张耀春 +2 位作者 王海明 姚淇誉 金路 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第5期91-102,共12页
A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic ... A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints. 展开更多
关键词 SEMI-RIGID thin-walled steel-concrete composite structures beam-to-column joints static behavior experimental study
下载PDF
The influence of temperature on creep behavior of Cu particle enhanced SnPb based composite soldered joints
20
作者 闫焉服 闫红星 +2 位作者 陈拂晓 张柯柯 朱锦洪 《China Welding》 EI CAS 2007年第1期41-46,共6页
Creep property of solder alloys is one of the important factors to affect the reliabdity of soldered joints in SMT (surface mount technology). Particle-enhancement is a way to improve the properties of solder alloys... Creep property of solder alloys is one of the important factors to affect the reliabdity of soldered joints in SMT (surface mount technology). Particle-enhancement is a way to improve the properties of solder alloys and has caused much more attention than before. Temperatures applied to soldered joints are one of the primary factors of affecting creep properties of particle enhancement composite soldered joints. In this paper single shear lap creep specimens with a 1 mm^2 cross-sectional area were fabricated using Cu particle enhancement 63Sn37 Pb based composite soldered joints and 63Sn37 Pb eutectic soldered joints to examine the influence of temperature on creep behavior of soldered joints. Results indicated that the creep resistance of soldered joints of Cu particle enhancement 63Sn37Pb based composite soldered joint was generally superior to that of the conventional 63Sn37Pb soldered joint. At the same time, creep rupture life of the composite soldered joint was declined with increasing temperature and drop faster than that of the conventional 63Sn37 Pb eutectic soldered joint. 展开更多
关键词 creep rupture life composite soldered joints particle-enhancement 63Sn37Pb TEMPERATURE
下载PDF
上一页 1 2 200 下一页 到第
使用帮助 返回顶部