They are drawn from a much larger "preform" block of material, in much the same way that conventional optical fibres are created.
它们从大块的材料上分离出来，其方法和传统的光学纤维提取差不多。
The key step in flashless forging is to optimize the design of preform die shape.
锻造过程实现净形和近净形制造最关键的一点是对预锻模进行优化设计。
Two methods used to liquid impregnate carbon fiber preform are introduced.
介绍了液相浸渍炭纤维坯体的两种方法。
Microstructures of the preform and the composite were analyzed under SEM and TEM.
利用SEM和TEM等方法对晶须预制块和复合材料进行了微观组织结构分析。
This preform is then heated to a temperature just below the melting point of the alloy.
此时，将初步加工的成品加热到一定的温度，这个温度要刚刚低于合金的熔点。
The fabric is used as a preform for thermoplastic textile-reinforced composite modules.
这种织物被用作热塑性纺织增强复合材料模件的预型件。
The fabric is used as preform for thermoplastic textile - reinforced composite modules.
这种织物被用作热塑性纺织增强复合材料模件的预型件。
The fabricating process of preform and factors having effect on it were also studied systematically.
系统地研究了预制块的制备工艺过程及影响因素。
When long-rod type forgings drop-forged, fullering and edging are often selected as preform operations.
在锤上模锻长杆类锻件时，常用滚挤和拔长工步进行制坯。
Densification process of carbon fibrous preform is divided into two procedures, CVI stage and SCVD stage.
炭纤维预形体的的增密工艺可分为CVI阶段和SCVD阶段。
The Bakelite resin could be compression molded from a loose powder or compressed into a preform, then molded.
胶木（即酚醛树脂）可从松散的粉末压缩模塑或先压缩预制成型，然后模塑。
This paper introduces basic principle about analysis 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。
Transverse feeding of molten metal in continuous fiber preform was investigated theoretically and experimentally.
研究了金属液在连续纤维预制型中的横向补缩。
The practice proves the reverse simulation technique is a very efficient approach to optimize the preform design.
实践证明，反向模拟技术对于预成形优化设计是一种非常有效的方法。
The above method can expand variety of the parts manufactured by tube preform. Part quality also can be improved.
采用上述方法可显著扩大用管坯制造零件的品种，并可提高制品的质量。
The proposed preform FE simulation optimization scheme is effective and overcomes the drawbacks of previous empirical design.
所提出的有限元模拟预成形优化方法十分有效，克服了以往凭经验设计的弊端。
The superior preform of composites is a basic requirement and one of key factors for fabricating superior properties composites.
摘要高质量复合材料预制块是获得高性能复合材料的基本要求和关键要素之一。
A cooling circuit for a neck ring of a preform is conformed to the surface of the neck ring by providing a neck ring in two parts.
本发明提供一种用于一预成型件的一颈环的冷却回路，其通过以两部分提供一颈环来与所述颈环的表面相配。
Forging quality and technical economic benefit of plastic working industries strongly depend on preform sequence and preform design.
锻件质量和锻造行业的技术经济效益很大程度上取决于预成形工步和预成形设计。
The effects of infiltration pressure, casting temperature and preform particles temperature on the preparation process were analyzed.
研究了渗流驱动压力、 铝熔体浇铸温度及模具预热温度对渗流过程的影响；
Numerical simulation results show that the optimal preform H/D dimension thus obtained can greatly reduce hammering times and die wear.
数值模拟结果表明获得的预成形H/D最佳尺寸可明显减少模锻锤击次数和模具磨损。
The invention is an integrally blow-moulded bag-in-container (2) obtainable by blow-moulding an injection moulded multi-layer preform (1).
本发明是一种可通过对注射成形的多层预制坯(1)进行吹塑来获得的一体吹塑内装袋容器(2)。
This paper addresses the shape optimization formulation for metal preform design problem, as well as the corresponding solution techniques.
研究了金属预成形设计中的形状优化设计问题及相应的求解算法，并讨论了凝聚函数在这类问题中的应用。
Preform design is one of the key steps in precise plastic forming, and backward simulation technology plays important role in preform design.
预成形毛坯设计是精密塑性成形工艺的核心环节，而反向模拟技术可以实现预成形设计的高效化、数字化和智能化。
Abstract: Forging quality and technical economic benefit of plastic working industries strongly depend on preform sequence and preform design.
文摘：锻件质量和锻造行业的技术经济效益很大程度上取决于预成形工步和预成形设计。
The preform design applying the method for preform optimization based on FEM can improve the deformation uniformity within forgings effectively.
应用基于正向有限元数值模拟和最优化方法进行坯料预成形设计的新方法，可显著提高锻件各部位的变形均匀性。
The porosity of porous Al-Si alloy is 40~80% and percentage of open-cell is above 85%, bom of which vary with the fabrication process of preform.
孔隙率在40～80%，孔隙连通率在85%以上，孔隙的大小和孔隙率取决于预制块的制备工艺。
The porosity of porous Al-Si alloy is 40~80% and percentage of open-cell is above 85%, bom of which vary with the fabrication process of preform.
孔隙率在40～80%，孔隙连通率在85%以上，孔隙的大小和孔隙率取决于预制块的制备工艺。
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