英汉数字词语的认知比较研究     

谢锦芳 《怀化学院学报》2007,26(1):108-109

在英语和汉语这两种高度发展的语言中,存在着大量的数字词语。数字词语是语言词汇的重要组成部分,也是语言的民族形成和各种修辞手段的集中表现。这些数字词语由于民族文化、地理环境、经济生活和认知思维的差异而具有不同的文化内涵。  相似文献   

提高数控编程课教学质量的探索     

杨兰福 《天津职业院校联合学报》2006,8(5):100-102

数控编程是一门新兴的、综合性、实践性较强的学科,要通过有限的课堂教学提高学生的数控理论知识水平,通过教学方法的改变提高学生的接受能力。要在课堂的理论教学中引入新的理念和方法的探索,提高教学质量,为培养紧缺人才做出贡献。  相似文献   

CQ5250立式车床的数控化改造     

庄晓龙 《金华职业技术学院学报》2006,6(3):17-19,46

普通立车进行数控改造可以取得良好的经济效益和应用效果,有利于提高企业的生产力和竞争力。本文通过对CQ5250普通立式车床的分析,提出了刀架、数控及进给伺服驱动系统、主轴传动的数控改造方案。  相似文献   

秃头悖论的数值分析     

吴新民 《唐山学院学报》2002,(1)

采用现代逻辑及数值分析方法分析了“秃头”一词的模糊性 ,揭示了“秃头悖论”产生的根源 ,进而提出了如何解决“秃头悖论”的问题。  相似文献   

高压水射流切割的CFD仿真研究   总被引：2，自引：0，他引：2  

谢汉江  王友民  王东  聂松林  刘文健 《武汉工程职业技术学院学报》2005,17(2):1-4,14

利用计算流体动力学(CFD)的方法对高压水射流流场进行了多相流的数值模拟分析。结果表明：射流在淹没流下的能量耗散远大于非淹没流；圆锥型射流喷嘴的射流效果好于圆柱型和锥直型；射流过程中不同直径的磨料对水速影响不大；靶距选择距离射流出口5～8D处，磨料颗粒和水柱速度达到最佳。  相似文献   

一类幅度自适应交叉耦合锁相环的仿真研究     

苏希鲁 《宁德师专学报(自然科学版)》1997,(1)

本文对一类幅度自适应交叉耦合锁相环系统(A—CCPLL)作仿真研究,并探讨其解调性能。  相似文献   

Global exponential stability of interval neural networks with a fixed delay     

LI Chuandong  LIAO Xiaofeng College of Mathematics  Physics  Chongqing University  Chongqing  P.R. China Department of Computer Science  Engineering  Chongqing University  Chongqing  P.R. China 《重庆大学学报(英文版)》2004,3(1):39-42

1.IntroductionConsideradelayedneural-networkmodeldescribedbythefollowingfunctionaldifferentialequations.()()()()()()11,nniiiijjjijjjijjtautwgutvgutImt===-++-+邋&1,2,,.in=K(1a)or()()()()()()ttttt=-++-+uAuWGuVGuI&,(1b)where()()()()T12,,,ntututut=轾臌uListhestatevectoroftheneuralnetwork;()12diag,,,naaa=AKisadiagonalmatrixwithpositiveentries,i.e.,0ia>;()ijnnw=Wand()ijnnv=Varetheconnectionweightmatrixanddelayedconnectionweightmatrix,re-spectively;()()()()()()()()T1122,,,nntgutgutgut轾=臌GuKde…  相似文献   

Experimental study and numerical simulation of the sludge concentration in a sedimentation tank     

SHENG Ming-jun  MA Lu-ming  ZHU Wei  WANG Hong-wu 《重庆大学学报(英文版)》2007,6(1):30-34

Sedimentation tanks and clarifiers play a significant role in an active sludge system, and the efficiency of the whole system is closely related with the design and operation of the sedimentation tanks. This paper focuses on the sludge concentration in each cross-section of the sedimentation tank. We measured the sludge concentration to explore its distribution inside the tank, carried in-situ tests to research the fluid pattern and real operational rules of the sedimentation tank. We also used the computational fluid dynamics (CFD) software, PHOENICS 3.5, to simulate the solid-liquid two-phase fluid inside the tank and describe the sludge concentration distribution. The numerical results indicate obviously a sludge-water interface and a compression interface inside the sedimentation tank, a stratified sedimentary region with uniform concentration and a compression region with high concentration at the bottom of the tank. Although the simulated concentrations deviated slightly from those of in-situ tests, they were still acceptable for identifying the sludge interfaces and fluid pattern inside a sedimentation tank, which are important parameters for optimizing the tank size and improving the settling efficiency.  相似文献   

Numerical Modeling of the Performance of R22 and R290 in Adiabatic Capillary Tubes Considering Metastable Two-Phase Region--Flow Characteristics and Parametric Analysis of R22 and R290     

Zhou Guobing  ZHANG Yufeng  HAO Hong 《天津大学学报(英文版)》2005,11(4)

Characteristics of R22 and its new alternative refrigerant R290 flowing through adiabatic capillary tubes are investigated based on the homogeneous model.Extensive flow variables along tube length such as pressure, temperature, viscosity, velocity, Reynolds number, friction factor and vapor quality etc are compared between the two fluids under the same operating condition. Two cases are considered, namely, either the same tube length or the same mass flow rate as inlet condition. The results show that the mass flow rate in the capillary tube of R290 is 40% lower than that of R22 due to the differences of physical properties between the two fluids. Further, a parametric analysis is performed and it appears that effects of geometric and thermodynamic parameters on mass flow rate of R290 are weaker than that of R22. When the condensing temperature is increased from 40 ℃ to 50 ℃, the mass flow rate for R22 is increased by 16%, while the increasing rate for R290 is 13%.  相似文献   

锦屏二级水电站深埋隧洞渗控研究   总被引：3，自引：0，他引：3  

王美芹 《长江工程职业技术学院学报》2003,20(4):26-28

用降雨入渗渗流有限单元法对锦屏二级水电站深埋隧洞最大埋深断面渗流场的水头分布进行了数值模拟。结合工程的现拟渗控措施经多种计算方案的求解，较详细地综合分析了各计算方案的渗控情况与特点，并获得了该断面隧洞支护上的外水压力及最优的渗控方案。  相似文献