查询词典 preform

Generalized Darcy's law was first derived from the study of fluid flow through a solid-fluid mixture,and the saturated permeability tensor of a preform could be predicted by studying its unit cell under periodic boundary conditions.

首先，采用均匀化理论分析了流体在多孔介质内的流动问题，推导出广义达西定律，证明以施加周期性边界条件的单胞为研究对象，可以预测预成型体的渗透率张量，并以单向纤维织物为例，对该方法进行了验证。

This paper introduces basic principle about anal ysis system of surface image of 3-D braiding composite preform.

介绍了三维编织复合材料预制件表面图像检测与纹理分析的基本原理。

Such as measurement of refractive index distribution is one of the most important test, and thus can be measured optical fiber preform of a series of geometric parameters such as core / package ratio, concentricity, roundness and so on.

比如折射率分布测量就是其中一项最重要的测试，并由此可测得光纤预制棒的一系列几何参数，如芯/包比、同心度、不圆度等。

High quality preform s are important for discontinuously reinforced composites made by the pressure infiltration method.

采用压力浸渗方法制备非连续增强复合材料需要高质量的预制块。

Considering the problems of spurgear precise plastic forming, such as high deformation resistance, poor flowability and especial hardness to fill cant of gear, technological plan was developed based on precise plastic forming technique, successive control principle and consecutive local deformation theory. Moreover, structures of the rolling preform die and the die with up and down wellrounded forcer for stamping-extrusion and bulge-extrusion combining forming were designed too.

因此本文的主要研究内容和结果如下：本文以某种直齿轮：模数m＝2，齿数z＝20，压力角α＝200，变位系数x＝0为对象，针对直齿轮精密塑性成形变形抗力大，流动性差，特别是成形中齿轮角隅部分更加难以充满问题，基于精密塑性成形技术、逐次控制原理以及连续局部变形原理提出了"直齿轮滚轧制坯－镦挤、胀挤复合精成形"的工艺方案，设计了滚轧制坯的模具结构和上下冲头带圆角的镦挤、胀挤复合精成形的模具结构。

In addition, the liquid impregnation of a preform by a pitch or some other precursor is described.

此外，一个预制的摊位或其他易制毒化学液体浸渍描述。

Otherwise,he will never be able to preform again.

否则，他不会是能的再预先形成。

With more than 20 years' development, the corporation has been the biggest PET preform production base in Asia.

历经二十几年的发展，公司已成为亚洲最大的PET瓶胚生产基地。

The results show that the best sintering process for SiC preform is 1100℃, 8 h in vacuum, by which the open porosity is 99.6% and the preform strength reaches 0.57 MPa. The thermo-physical characteristics of 57% SiCp/Al composites produced by this technique are as follows: the relative density is 98.7%; the thermal expansion coefficient is 7.5×10-6 ℃-1 which almost matches those of GaAs and BeO; the thermal conductivity is 1.65×105 W/K, which corresponds to that of Cu(15%)/W and decuples that of Kovar alloy; the density is close to that of aluminum and less than that of one fifth of Cu/W.

结果表明：经1 100 ℃真空烧结8 h的SiC预成形坯开孔率可以达到99.6%，抗压强度为0.57 MPa；所制备的57％SiCp/Al复合材料相对密度为98.7％，热膨胀系数为7.5×10-6 ℃-1，与GaAs、 BeO的接近，热导率为1.65×105 W/K，与传统Cu(15%)/W相当，是柯伐合金的10倍，在密度上接近Al，不到Cu/W的1/5。

Primarily study on preparation for EVA hot melt adhesive with disproportionated rosin of esterification modified as tackifier ;2. Development and Applications of Rubber Tackifier TKO Series Products;3. Several tackifier s and molding methods used in fiber preform preparation technology were analyzed and summarized, and the development trend of tackified fiber preform preparation was prospected.

总结了20世纪90年代以来关于复合材料液体模塑成型技术中纤维预成型体制备技术的相关文献报道，指出LCM用纤维预成型体应满足的工艺性要求，且对当前国内外纤维预成型体的成型方法及其制备技术中应用的几种增粘剂进行了分析和概述，并对纤维预成型体制备技术的发展方向进行了展望。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐