查询词典 conductivity for heat

A theoretical model is built to investigate the simulation of the infrared characteristic of the metal structure with the PCM false target.Structure parameters of the PCM false target that suit for the simulation are investigated numerically.According to the results,further request on the improvement of the thermal conductivity of PCM is presented.An experimental platform is built and the numerical model is validated experimentally.Three key thermal characteristic components of the false tank(barbette,wheel and front armor plate) are manufactured and tested,and good results are obtained.A method for the thermal conductivity enhancing of PCM by using aluminum fins is studied,the influence of the structure parameters of PCM plates to the simulation effects are investigated numerically,and the reasonable configuration parameters of the PCM plates used to simulate the steel plates of different thickness are obtained.In the study of the application of heat convection method in IR false target,a passive infrared simulation system is designed to simulate the infrared characteristic of metal constructions.The system is made up of pipe-plate,pump,receiver,and working fluid.

在相变材料应用于红外示假的研究中，通过数值模拟，研究确定了适用于制作假目标的相变材料各物性参数的范围，分析了相变材料制作假目标的可行性，并根据所得结果，选取石蜡为研究对象，建立了相变材料模拟金属构件红外特征的理论模型，研究了适用于模拟各金属构件红外特征的相变材料假目标的相关结构参数，得出了相变材料假目标模拟各金属构件红外特征的理论结果，并对相变材料的导热系数这一物性提出了进一步的改进要求；搭建了假目标实验平台，验证了所建理论模型的准确性；以坦克假目标为研究对象，制作了炮塔、负重轮和前上装甲板三个坦克假目标的关键红外热特征部件，并进行了野外实验，取得了较好的结果；以添加铝肋片作为改进相变材料导热能力的手段，理论研究了此类导热增强型相变材料的相关结构参数对模拟效果的影响，得出了模拟不同厚度钢板红外特征的导热增强型相变材料的结构参数及模拟效果。

The measurement of thermal conductivity for low temperature frozen soil is important in researching the heat physical characteristics and the frost heaving of soil.

冻土导热系数的测定对于研究冻土热物理性质、土体冻胀特性有着重要作用。

In this paper the technique of Thermo Time Domain Reflectometry is introduced to make measurements of a wide range of soil physical properties.We outline the theories of TDR technique for water content and electrical conductivity measurement, and heat pulse technique for determination of volumetric heat capacity, thermal conductivity, and thermal diffusivi...

本文以热脉冲技术和时域反射技术的理论为基础，介绍了利用热脉冲技术时域反射技术连续定位测定土壤含水量、电导率、温度和热特性的原理，并利用土壤热特性与容重和含水量的关系，导出了土壤容重、饱和度和通气孔度的计算公式。

Addition of steel bar can increase conductivity for heat, and reduce specific heat of concrete.

钢筋的加入可以提高混凝土的导热性能，减小混凝土的比热。

A method using a tiny thermistor as heat transfer model was developed to measure thermophysical properties (thermal conductivity and thermal diffusivity) of three standand samples(ethanol, ethylene alcohol, solution of calcium chloride). Results showed that there was no significant difference between measurement and recommendation; results of thermal conductivity from thermistor method and heat probe method for carrot and potato samples showed no significant difference; results of thermal diffusivity between thermistor method and calculation for carrot and potato samples showed no significant difference.

在分析微珠状热敏电阻传热模型的基础上，在室温对标准样品（乙二醇、乙醇、氯化钙的水溶液）的热物性进行测定，结果显示，导热系数及热扩散系数的测量值与推荐值之间无显著性差异（p＞0.05）；热敏电阻法与热探针法对比测定胡萝卜及马铃薯两种农产品的导热系数，结果显示两种方法之间无显著性差异（p＞0.05）；热敏电阻法与常规计算对比测定胡萝卜及马铃薯两种农产品的热扩散系数，结果显示两种方法之间无显著性差异（p＞0.05）。

The relative conductivity of leaves, ultrastructural changes of mesophyllous cells under heat acclimation and heat stress, the differences in gene expression of leaves under hest shock can be used as physiologic, cytologic and molecular biologic indexes respectively for evaluating heat tolerance.

在热锻炼和热胁迫过程中叶片相对电导率、叶肉细胞超微结构的变化，以及热击条件下叶片基因表达差异，可分别作为耐热性评价的生理学、细胞学和分子生物学指标。

In first, a new short time formula of one dimension heat conduction differential equation, based on the theory of one dimension transient method, is presented for thermophysical property measurement of wood. The result of testing on red pine and larch wood arc satisfied by new method.In succession, the relationship between heat conductivity of wood and moisture, density, porosity, temperature and grain is studied experimentally in the range from 25 to 100℃. The result shows that, the heat conductivity is in direct proportion to density. but in inverse proportion to porosity. The heat conductivity of air-dried wood increased probably linear with the temperature rising. And that heat conductivity along the grain of wood is higher than that cross the grain. The former is 1.8 or 2 times of the latter.

文中研究了25～100℃范围内，气干木材的导热系数与含水率、密度、孔隙率、温度及热流方向的关系，研究表明：木材导热系数与密度成正比关系，与孔隙率成反比关系：对于针叶材，导热系数与密度及孔隙率成线性变化关系，而对于阔叶材其变化关系近似成二次曲线；气干木材的导热系数随着温度的升高近似呈线性增加：热流平行于纹理方向的导热系数大于垂直于纹理方向的导热系数，两者的比值大约在1.8～2之间。

The value of the loss, the equivalent of heat conductivity for stator coil and the thermal convection coefficient of convection faces are researched in this paper.

同时，在异步温度场的计算和分析中，绝缘层常常被忽略，但由于绝缘材料的导热系数很小，在一个很薄的股线绝缘层上将会有一个显著的温度变化。

The heat conductivity calculation has been divided into two parts, form the borehole to the exposure of cement mantle and in the formations, as for corresponding to different borehole structures, different methods have been adopted to sum the overall heat transfer coefficients and numerical method is used to calculate the heat loss on each nodal point, furthermore, through the model proposed herein, the degrees of influences of different borehole structures on heat loss could be calculated in order to get the most economic and efficient borehole structure.

把导热分为井筒到水泥环外壁和地层导热两部分计算，对不同的井筒结构采用不同方法计算总传热系数，数值法求解每个节点处的热损失，并通过模型对比计算了不同井筒结构对井筒热损失的影响程度，得到最经济有效的井筒结构。

The theories proposed by Wilson (1994) were adopted to describe the fundamental behaviors of temperature and variation of suction of soil. The Darcy's law and Pick's law described the flows and evaporation of water respectively. Some proposed assumptions including the characteristic curve of volumetric water content and hydraulic conductivity were only related to the suction of unsaturated soil. The coefficient of latent heat for water was a linear function of temperature; and the heat conductivity was calculated according to the equation proposed by De Vries.

对于土体的温度和吸力变化特征，采用Wilson提出的理论加以描述，在此理论中，分别利用Darcy和Fick定律描述水和蒸汽的流动规律，土水特征曲线和水力传导系数假定仅仅相关于非饱和土吸力，水的潜热系数是温度的线性函数，温度传导系数采用De Vries建议方程加以计算。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。