表观误差

With the establishmentof the equivalent medium model, RTM-DRE was applied to study radiative transfer intransparent medium with scattering particles. By taking into account of absorption andscatter of particles, absorption of binder and reflection of interface, the apparent spectrumabsorption model of thermal control coatings was developed by RTM-DRE combined withMies theory. Validity, computational error and time of the model were validated andanalyzed. Furthermore, the apparent spectrum absorption characteristics of thermal controlcoatings were studied, and the influences of optical characteristics of binder and particles,volume fraction of particles, particles diameter, characteristics of interface, and incidentangle of irradiance were analyzed.

采用RTM-DRE研究热控涂层内辐射传递，结合Mie氏散射理论，考虑粒子吸收与散射、基料吸收、界面反射等因素影响，建立热控涂层表观光谱吸收率计算模型，验证计算模型的正确性，分析计算模型的计算误差与计算时间；在此基础上，通过计算热控涂层表观光谱吸收率来研究热控涂层表观光谱吸收特性，分析基料与粒子光学特性、粒子体积份额、粒径、界面反射特性、辐射能量入射角等因素的影响，初步研究空间环境因素对热控涂层表观光谱吸收特性的影响，采用系统灵敏度理论定量分析热控涂层表观光谱吸收特性变化对卫星温度的影响。

A variable-step modified Euler time integration method is proposed and analyzed. Four major factors that affect the efficiency of the variable-step modified Euler time integration method are discussed. These include stability and accuracy analysis for the damped fix-step modified Euler integration formula, adjustment method of the fix-step basic integration formula to accommodate step-size changes, suitable range of the step-size selection strategy based on truncation error concept and development of the step-size selection strategy based on apparent frequency concept to satisfied the specified error bound and stability condition.

提出了变步长修正Euler时间积分法，详细讨论了影响变步长修正Euler时间积分算法效率的四个主要因素，它们包括：有阻尼问题的修正Euler法的稳定性和精度分析，调整固定步长的基本积分公式使之容纳步长大小变化的研究，基于截断误差概念的步长大小选择策略适用范围的讨论，同时满足规定误差界和稳定性条件的、基于表观频率概念的步长大小选择策略的建立。

First by testing the practical multilayer insulation in a cryogenic tanker, which is the carilometer in my paper,some affecting factors on multilayer insulation are analysed, then by using the low-temperature and vacuum environment caused by multilayer insulation, the effective thermal conductivity of multiple fiber paper with 5 layers is tested.Through Newton interativemethod,an empirical formula is deduced to computer the thermal conductivity of fiber paper,The errors between experimental thermal conductivity and the calculated conductivity by empirical formula are below10%,so the formula of fiber conductivity can be applied to practical enginnering.

为探索改善工程应用中高真空多层绝热层绝热性能的方法，本文实验研究中首先测量了包扎在实际低温储罐上不同结构的高真空多层绝热层的绝热性能，并分析了环境温度、环境压力，层数、不同隔热材料的组合等因素对工程应用中的高真空多层材料绝热性能的影响；然后利用多层绝热层中的低温真空环境测量5层干法纸在不同温度区间内的表观导热系数，在有限实验数据的基础上用牛顿迭代数值拟和出计算5层干法纸表观导热系数的经验公式，对比经验公式计算值和实验测量值，发现二者的误差在10%以内，因此在工程应用中可用本文的经验公式计算干法纸在低温下的导热系数。

It shows that the measuring error of the rheometer is less than 5% by experiments and theoretical calculation. Thus, it can provide reliable and accurate experimental data for apparent viscosity of semi-solid alloys.

实验检验和理论计算表明，该流变仪的测量误差＜5％，从而保证了实验测量数据的可靠性，为精确研究半固态金属熔体的表观粘度提供了实验基础。

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％。