导热能力

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 boundary conditions and the latent heat of heat transfer system have been treated by heat-enthalpy method.

在这样的充填条件下，虽然金属压铸模的导热性很高，蓄热能力很强，但要求在压铸模型腔内获得形状完整、轮廓清晰、尺寸精度高的铸件，必须得选用合理的模具结构和压铸工艺，而压铸模具的尺寸精度和使用寿命在很大程度上取决于其在压铸过程中热应力和其产生的变形。

At present, we offer high quality high proportion fishing fall, high proportion alloy ball, high proportion alloy round stick, high proportion alloy unit, high proportion alloy golf head, high proportion alloy off-centered dipole and other high proportion alloy abnormal units. Production capacity: above 200T/year.

按合金组成特性及用途分为W-Ni-Fe、W-Ni-Cu、W-Co、W-WC-Cu、W-Ag等主要系列，其密度高达16 。5-19.0g/cm3，而被世人称为高比重合金，它还具有一系列优异的特性，比重大：一般比重为16.5-18.75g/cm3，，强度高：抗拉强度为700-1000Mpa，吸收射线能力强：其能力比铅高30-40%，导热系数大：为模具钢的5倍；热膨胀系数小：只有铁或钢的1/2-1/3，良好的可导电性能；具有良好的可焊性和加工性。

All Duraboard products offer low thermal conductivity, high temperature stability, uniform density, and excellent resistance to thermal shock and chemical attack.

所有Duraboard产品都具有低导热率、高温稳定性、均匀的密度，以及优异的抗热冲击及化学侵蚀能力。

Ag-W contact possesses good thermal and electrical conductivity, abradability, fusion welding resistance, and oxidation resistance.

Ag-W触头具有良好的导热和导电性能、耐电磨损性能、抗熔焊性能、抗氧化能力等优点。

To make the measure of area of large-grained spherical copper powder reach 70~80% of the working area or so, achieving the purpose of even alternately distributing of copper powder and POM. It has a good comprehensive ability of load-bearing, friction and wear endurance, creep resistance and heat conduction.

我们通过机械加工，使大颗粒球形铜粉分布在工作面的面积达到70~80%左右，形成铜粉与改性聚甲醛基本均匀相间分布的状况，其承载能力、摩擦磨损性能、抗蠕变能力和导热性等综合特性较好。

On the basis of thorough analysis on the service condition of brake disk of automobile, this paper puts forward the mechanic properties that brake disk should have: higher intensity and abrasion resistant ability, high heat retaining performance, good heat durability, and good vibration damping resistance.

在全面分析汽车制动盘的服役条件的基础上提出了制动盘应当具备的机械性能：较高的强度和耐磨损能力；高的蓄热性、良好的导热性与抗热裂性；抗振动衰减和抑制振鸣效果好。

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％。