期刊文献+
共找到16篇文章
< 1 >
每页显示 20 50 100
Capacity of Mixed Traffic Flow Crossing Multi-Major-Lanes 被引量:2
1
作者 李文权 王炜 周刚 《Journal of Southeast University(English Edition)》 EI CAS 2000年第2期100-104,共5页
Based on the gap acceptance theory, the mixed traffic flow composed of r representative types of vehicles 1, 2,…, r vehicles is analyzed with probability theory. Capacity model of the minor mixed traffic flow ... Based on the gap acceptance theory, the mixed traffic flow composed of r representative types of vehicles 1, 2,…, r vehicles is analyzed with probability theory. Capacity model of the minor mixed traffic flow crossing m major lanes with M3 distributed headway on the unsignalized intersection is set up, and it is an extension of capacity model for one minor lane vehicle type crossing one major lane traffic flow. 展开更多
关键词 M3 distribution HEADWAY gap acceptance traffic flow capacity
下载PDF
中学师生之间信息不对称的表现及对策研究
2
作者 胡江红 《现代教育科学(中学教师)》 2015年第1期30-31 39,39,共3页
信息不对称是指在当事人双方中,一方拥有信息,但另一方不拥有信息;或者一方掌握的信息多一些,而另一方掌握的信息少一些。信息不对称会影响处于信息弱势的一方做出正确的决策并导致行动效率低下;处于信息优势的一方也可能利用信息不对... 信息不对称是指在当事人双方中,一方拥有信息,但另一方不拥有信息;或者一方掌握的信息多一些,而另一方掌握的信息少一些。信息不对称会影响处于信息弱势的一方做出正确的决策并导致行动效率低下;处于信息优势的一方也可能利用信息不对称做出损害信息弱势另一方利益的事情。师生之间也存在信息不对称,而且信息不对称是双向的,即有些情况下老师掌握的信息比学生多,而有些情况下学生掌握的信息比老师多。师生之间的信息不对称影响到双方之间的有效沟通,特别是学生掌握的信息比老师多的时候。 展开更多
关键词 信息不对称 中学师生 学习态度 学习效果 教学材料 互动效果 互动式教学 课外时间 教育措施 间接交
下载PDF
A Study of ISA in Chinese Cultural Communication 被引量:1
3
作者 周华 韩晓惠 成城 《Sino-US English Teaching》 2007年第3期66-69,共4页
The paper tentatively studies the function of the indirect speech act in Chinese cultural communication, namely, domestic communication. Two aspects are shown in this paper: communication between people of different ... The paper tentatively studies the function of the indirect speech act in Chinese cultural communication, namely, domestic communication. Two aspects are shown in this paper: communication between people of different social status, genders and casual relationships, and communication between people of same social status, genders and close relationships. Therefore, the study result can be concluded like this: whether the use of indirect speech act is successful or not always influences people's communication significantly. 展开更多
关键词 Indirect Speech Act Chinese cultural communication gender difference
下载PDF
变频调速及矢量控制系统仿真
4
作者 肖玲娟 崔庆渝 任伟 《机电设备》 2004年第3期20-24,共5页
根据使用电流模型的异步电动机矢量控制系统的结构框图,采用交-直-交间接变频器,以实际电机为例,利用simulink仿真软件,验证了矢量控制的有利性.
关键词 船舶工程 -直-间接变频器 矢量控制系统 电流模型 simulink软件 船舶电气系统
下载PDF
Synthesis of indirect work exchange networks considering both isothermal and adiabatic process together with exergy analysis 被引量:2
5
作者 Yu Zhuang Linlin Liu +1 位作者 Lei Zhang Jian Du 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1644-1652,共9页
In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In co... In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method. 展开更多
关键词 Work exchange networks Transshipment model Adiabatic process Exergy analysis Isothermal process Work cascade
下载PDF
Fork-Join program response time on multiprocessors with exchangeable join 被引量:1
6
作者 WANG Yong-cai ZHAO Qian-chuan ZHENG Da-zhong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第6期927-936,共10页
The Fork-Join program consisting of K parallel tasks is a useful model for a large number of computing applications. When the parallel processor has multi-channels, later tasks may finish execution earlier than their ... The Fork-Join program consisting of K parallel tasks is a useful model for a large number of computing applications. When the parallel processor has multi-channels, later tasks may finish execution earlier than their earlier tasks and may join with tasks from other programs. This phenomenon is called exchangeable join (EJ), which introduces correlation to the task’s service time. In this work, we investigate the response time of multiprocessor systems with EJ with a new approach. We analyze two aspects of this kind of systems: exchangeable join (EJ) and the capacity constraint (CC). We prove that the system response time can be effectively reduced by EJ, while the reduced amount is constrained by the capacity of the multiprocessor. An upper bound model is constructed based on this analysis and a quick estimation algorithm is proposed. The approximation formula is verified by extensive simulation results, which show that the relative error of approximation is less than 5%. 展开更多
关键词 Exchangeable join First come first served (FCFS) Fork-Join MULTIPROCESSOR Response time
下载PDF
Capacity models on expressway near a bus bay stop with an access 被引量:3
7
作者 张洪宾 孙小端 +1 位作者 贺玉龙 宇仁德 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期3239-3246,共8页
To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depe... To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access. 展开更多
关键词 capacity public transport entrance and exit traffic flow theory DELAY
下载PDF
Deep removal of copper from cobalt sulfate electrolyte by ion-exchange 被引量:1
8
作者 温俊杰 张启修 +1 位作者 张贵清 曹左英 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第8期1534-1540,共7页
SP-C was applied for the removal of Cu^2+ from simulated cobalt sulfate electrolyte containing Co2+ 50 g/L and Cu2+ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time o... SP-C was applied for the removal of Cu^2+ from simulated cobalt sulfate electrolyte containing Co2+ 50 g/L and Cu2+ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time of 10-40 min. The investigation demonstrated that SP-C had recommendable efficiency in adsorbing Cu2+ from the electrolyte with 25- to 100-fold of Co2+ The optimal adsorption conditions of SP-C were pH of 4, contact time of 30 min and ambient temperature. The study also showed that the loaded resin could be effectively eluted with 2.0 mol/L H2SO4 solution at a contact time of 40 min; the peak concentration of Cu2+ in the eluate was about 35 g/L. The sorption characteristics of Cu2+ by SP-C could be described by Langrnuir isotherm and the pseudo second-order kinetic equation. Infrared spectra showed that nitrogen atoms in the functional group coordinated with Cu2+ to form coordination bands. 展开更多
关键词 cobalt sulfate electrolyte removal of copper chelating resin ion exchange
下载PDF
Effect of airplane transport of donor livers on post-liver transplantation survival
9
作者 Yi Huang Gerry MacQuillan +7 位作者 Leon A Adams George Garas Megan Collins Albert Nwaba Linjun Mou Max K Bulsara Luc Delriviere Gary P Jeffrey 《World Journal of Gastroenterology》 SCIE CAS 2016年第41期9154-9161,共8页
AIM To evaluate the effect of long haul airplane transport of donor livers on post-transplant outcomes. METHODS A retrospective cohort study of patients who received a liver transplantation was performed in Perth, Aus... AIM To evaluate the effect of long haul airplane transport of donor livers on post-transplant outcomes. METHODS A retrospective cohort study of patients who received a liver transplantation was performed in Perth, Australia from 1992 to 2012. Donor and recipient characteristics information were extracted from Western Australian liver transplantation service database. Patients were followed up for a mean of six years. Patient and graft survival were evaluated and compared between patients who received a local donor liver and those who received an airplane transported donor liver. Predictors of survival were determined by univariate and multivariate analysis using cox regression.RESULTS One hundred and ninety-three patients received alocal donor liver and 93 patients received an airplane transported donor liver. Airplane transported livers had a significantly lower alanine transaminase(mean: 45 U/L vs 84 U/L, P = 0.035), higher donor risk index(mean: 1.88 vs 1.42, P < 0.001) and longer cold ischemic time(CIT)(mean: 10.1 h vs 6.4 h, P < 0.001). There was a weak correlation between CIT and transport distance(r2 = 0.29, P < 0.001). Mean follow up was six years and 93 patients had graft failure. Multivariate analysis found only airplane transport retained significance for graft loss(HR = 1.92, 95%CI: 1.16-3.17). One year graft survival was 0.88 for those with a local liver and was 0.71 for those with an airplane transported liver. One year graft loss was due to primary graft non-function or associated with preservation injury in 20.8% of recipients of an airplane transported liver compared with 4.6% in those with a local liver(P = 0.027). CONCLUSION Airplane transport of donor livers was independently associated with reduced graft survival following liver transplantation. 展开更多
关键词 Airplane transportation Cold ischemic time Graft survival Donor location Organ damage
下载PDF
Microscopic dynamic simulation model for pedestrian at signalized intersection 被引量:2
10
作者 李珊珊 钱大琳 罗艺 《Journal of Central South University》 SCIE EI CAS 2012年第11期3351-3362,共12页
Pedestrian's road-crossing model is the key part of micro-simulation for mixed traffic at signalized intersection.To reproduce the crossing behavior of pedestrians,the microscopic behaviors of the pedestrians pass... Pedestrian's road-crossing model is the key part of micro-simulation for mixed traffic at signalized intersection.To reproduce the crossing behavior of pedestrians,the microscopic behaviors of the pedestrians passing through the crosswalk at signalized intersection were analyzed.A pedestrian's decision making model based on gap acceptance theory was proposed.Based on the field data at three typical intersections in Beijing,China,the critical gaps and lags of pedestrians were calibrated.In addition,considering pedestrian's required space,a modification of the social force model that consists of a self-deceleration mechanism prevents a simulated pedestrian from continuously pushing over other pedestrians,making the simulation more realistic.After the simple change,the modified social force model is able to reproduce the fundamental diagram of pedestrian flows for densities less than 3.5 m-2 as reported in the literature. 展开更多
关键词 communication and transportation system pedestrian simulation social force model decision making model fimdamental diagram mixed traffic
下载PDF
Develope Monoclonal Antibody against Foot-and-mouth Disease Virus A Type
11
作者 Tong Lin Jing Li Jun-jun Shao Guo-zheng Cong Jun-zheng Du Shan-dian Gao Hui-yun Chang 《Virologica Sinica》 SCIE CAS CSCD 2011年第4期273-278,共6页
In order to develop an anti-FMDV A Type monoclonal antibody (mAb), BABL/c mice were immunized with FMDV A type. Monoclonal antibodies (mAbs) 7B 11 and 8H4 against Foot-and-mouth disease virus (FMDV) serotype A w... In order to develop an anti-FMDV A Type monoclonal antibody (mAb), BABL/c mice were immunized with FMDV A type. Monoclonal antibodies (mAbs) 7B 11 and 8H4 against Foot-and-mouth disease virus (FMDV) serotype A were produced by fusing SP2/0 myeloma cells with splenocyte from the mouse immunized with A/AV88. The microneutralization titer of the mAbs 7Bll and 8H4 were 1024 and 512, respectively. Both mAbs contain kappa light chainS, the mAbs were IgG1. In order to define the mAbs binding epitopes, the reactivity of these mAbs against A Type FMDV, were examined using indirect ELISA, the result showed that both mAbs reacted with A Type FMDV. These mAbs may be used for further vaccine studies, diagnostic methods, prophylaxis, etiological and immunological research on FMDV. Characterization of these ncindicated that prepared anti-FMDV A mAbs had no cross-reactivity with Swine Vesicular Disease (SVD) or FMDV O, Asial and C Type antigens. Their titers in abdomen liquor were 1:5×10^6 and 1:2×10^6, respectively. 7B 11 was found to be of subtype IgGb 8H4 was classified as IgG2b subtype. The mAbs prepared in this study, are specific for detection of FMDV serotype A, and is potentially useful for pen-side diagnosis. 展开更多
关键词 Foot-and-mouth disease virus (FMDV) A Type Monoclonal antibody (mAb) Neutralizing activity
下载PDF
Schedule algorithm for mitigating inter-cell interference based on orthogonal complement space
12
作者 付少忠 葛建华 《Journal of Central South University》 SCIE EI CAS 2011年第2期499-503,共5页
In order to avoid severe performance degradation led by the inter-cell interference (ICI) in orthogonal frequency division multiple access (OFDMA) systems with a frequency reused factor (FRF) of 1,distributed schedule... In order to avoid severe performance degradation led by the inter-cell interference (ICI) in orthogonal frequency division multiple access (OFDMA) systems with a frequency reused factor (FRF) of 1,distributed schedule algorithm (DS-OCS) and distributed proportional fairness schedule algorithm (DPFS-OCS) based on orthogonal complement space (OCS) were proposed. The first right and left singular vectors of the channel that the user experienced were selected as the transmitting and receiving beamforming vectors. An interference space was spanned by the left singular vectors of the entire interference users in the same channel. The most suitable user lay in the OCS of the interference space was scheduled to avoid suffering interference from neighboring cells based on the criterion of system capacity maximizing and proportional fairness. The simulation results show that the average system capacity can be improved by 2%-4% compared with the DS-OCS algorithm with the Max C/I algorithm,by 6%-10% compared with the DPFS-OCS algorithm with the PF algorithm. 展开更多
关键词 long term evolution interference avoidance schedule algorithm orthogonal complement space FAIRNESS
下载PDF
Resource allocation for NOMA-based vehicular communications
13
作者 Jiang Wei Song Tiecheng +1 位作者 Wang Cong Hu Jing 《Journal of Southeast University(English Edition)》 EI CAS 2020年第1期8-13,共6页
To solve fast channel variations induced by the mobility of the vehicles and achieve effective and reliable vehicular communications,the non-orthogonal multiple access is applied to the vehicle to vehicle(V2V)pairs un... To solve fast channel variations induced by the mobility of the vehicles and achieve effective and reliable vehicular communications,the non-orthogonal multiple access is applied to the vehicle to vehicle(V2V)pairs underlaid vehicle to infrastructure(V2I)users to solve the downlink resource allocation.A geographic position-based clustering algorithm for V2V users is proposed.The base station preassigns the channel resources and the Kuhn-Munkres algorithm is used to complete the channel assignment.Then,the verified particle swarm optimization(PSO)is adopted to achieve the optimal power allocation.The simulation results show that the proposed scheme outperforms the existing device to device(D2D)mechanism by improving the network connectivity,spectrum efficiency and data transmission rate. 展开更多
关键词 non-orthogonal multiple access vehicle to vehicle vehicle to infrastructure subchannel assignment power control
下载PDF
AN ANALYSIS ON LARGE-SCALE AIR-SEA INTERACTIVE LINKAGES BETWEEN THE TROPICAL INDIAN OCEAN AND THE PACIFIC OCEAN DURING ENSO EVENTS 被引量:1
14
作者 邓北胜 刘海涛 丑纪范 《Journal of Tropical Meteorology》 SCIE 2010年第4期305-312,共8页
By utilizing a 3-D atmospheric circulation resolving method, the authors studied the air-sea interactive linkages between the tropical Indian Ocean and the Pacific Ocean in 1979-2008 E1 Nifio-Southern Oscillation (E... By utilizing a 3-D atmospheric circulation resolving method, the authors studied the air-sea interactive linkages between the tropical Indian Ocean and the Pacific Ocean in 1979-2008 E1 Nifio-Southern Oscillation (ENSO) events. Their findings showed that evident 3-D gear-coupling characteristics existed in the 1979-2008 ENSO events. Their resolving analyses also suggested that the general circulation showed stronger and wider sinking motions over the eastern Indian Ocean-western Pacific during the mature phase of 1979-2008 ENSO events, compared with the vertical velocities from the U.S. National Centers for Enviornmental Prediction (NCEP) reanalysis data. With their 3-D analysis method, the vertical velocity was resolved by two components, i.e. zonal and meridional components. It was found that the zonal component of the vertical velocities showed a strong sinking motion while the meridional components showed an upward motion during the prevailing phases of the ENSO events. In the tropics, the zonal component of the vertical velocities was found greater than the meridional component, reflecting the dominant characteristics of the vertical velocity, and the overall outcomes showed a strong sinking motion, although the two components also partially offset each other in the processes. Compared with the vertical velocities from NCEP reanalysis, the vertical motions calculated with the 3-D resolving analysis method demonstrate some advantages. 展开更多
关键词 air-sea interactive linkages between the tropical Indian Ocean and the Pacific Ocean gear coupling of atmospheric circulation 3-D resolving method of atmospheric circulation ENSO event
下载PDF
Distribution optimization of circulating water in air-cooled heat exchangers for a typical indirect dry cooling system on the basis of entransy dissipation 被引量:4
15
作者 SUN Jian YUAN Kai +3 位作者 YANG Li Jun CHEN Lin DU Xiao Ze YANG Yong Ping 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第4期617-629,共13页
The flow and heat transfer of air-cooled heat exchangers play important roles in the performance of indirect dry cooling systems in power plants,so it is of benefit to the design and operation of a typical indirect dr... The flow and heat transfer of air-cooled heat exchangers play important roles in the performance of indirect dry cooling systems in power plants,so it is of benefit to the design and operation of a typical indirect dry cooling system to optimize the thermo-flow characteristics of air-cooled heat exchangers.The entransy dissipation method is applied to the performance optimization of air-cooled heat exchangers in this paper.Two irreversible heat transfer processes in air-cooled heat exchangers,the heat transfer between circulating water and cooling air and the mixing of circulating water,are taken into account and analyzed by means of the entransy dissipation method.The total entransy dissipation rate,which connects the geometrical parameters of air-cooled heat exchanger sectors and the heat capacity rates of the fluids to the heat flow rate in every sector,is obtained.Based on the mathematical relation and the conditional extremum method,an optimization equation group is derived,by which the air-cooled heat exchanger with known air-side parameters is optimized,showing that the entransy dissipation based optimization approach can contribute to the distribution optimization of circulating water in air-cooled heat exchangers of a typical indirect dry cooling system. 展开更多
关键词 indirect dry cooling system air-cooled heat exchanger entransy dissipation OPTIMIZATION
原文传递
A new approach for teleoperation rendezvous and docking with time delay 被引量:8
16
作者 ZHOU JianYong JIANG ZiCheng TANG GuoJin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第2期339-346,共8页
Teleoperation rendezvous and docking can be used as a backup for autonomous rendezvous and docking (RVD) for an unmanned spacecraft or for guiding the chaser docking with an uncooperative target.The inherent teleopera... Teleoperation rendezvous and docking can be used as a backup for autonomous rendezvous and docking (RVD) for an unmanned spacecraft or for guiding the chaser docking with an uncooperative target.The inherent teleoperation time delay is a rigorous problem,especially when the chaser is teleoperated on the ground.To eliminate the effect of time delay,a new approach for teleoperation RVD is studied.The characteristics of teleoperation RVD are analyzed by comparisons with the teleoperation robot and with manually controlled RVD;the relative motion of the chaser is predicted based on the C-W equation;and the processed measure information with time delay through the Kalman filter is utilized to correct the current prediction.Experimental results verify that the approach produces an 18% enhanced success rate of teleoperation RVD compared with direct visual feedback,and consumes less time and fuel.The developed approach also solves the time delay problem effectively.Teleoperation RVD using this method can be applied as a useful backup for autonomous RVD. 展开更多
关键词 TELEOPERATION rendezvous and docking (RVD) predictive display time delay
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部