It is mainly synthesized by two chemical ways: ring-opening polymerization and direct polycondensation.

The N-methyl-2-pyrrolidone is chosen as polycondensation media and toluene as carrier of water.

选择N - 甲基 -2- 吡咯烷酮为反应介质,甲苯为带水剂.

Staring from D , Llactic acid , poly ( DLlactic acid ) ( PDLLA ) was directly synthesized through melt polycondensation.

以DL- 乳酸为原料, 通过熔融聚合法直接合成外消旋 聚乳酸 (PDLLA).

The shaft seal leakage, judgement and emergency measures of the final polycondensation reactor was introduced.

介绍了终缩聚反应器轴封泄漏的现象 、 判断和应急措施.

The esterification, polyesterification , polycondensation and the formation of diethylene glycol ( DEG ) reaction kinetic parameters were obtained.

获得了酯化反应 、 酯化缩合反应 、 缩聚反应以及二甘醇生成反应的动力学参数.

The key equipment in polycondensation phase of non-phosgene process was emphatically introduced.

同时,介绍了 非 光气法缩聚阶段的关键设备.

A new mounting technology for synthetic diamond polycrystal-cubic anvil high-pressure technology is developed.

提出一种人造聚晶金刚石镶套新工艺———六面顶高压镶套工艺.

The present invention introduces transparent polycrystal used as luminous panel substrate in CRT.

本发明介绍用透明多晶体作阴极射线管发光面板的基片.

Infrared polycrystal optical materials ZnS were manufactured using chemical vapor deposition ( CVD ) method in this paper.

采用 化学气相沉积 方法成功地生长出硫化锌多晶红外光学材料.

With the polycrystal, PbI _ 2 single crystal with size of? 15 mm ×30 mm has been grown by vertical Bridgman method.

以此为原料,用垂直Bridgman法生长出尺寸为? 15mm×30mm的PbI2单晶锭.

Selected-area electron diffraction ( SAED ) confirmed that SnO 2 nanorods are polycrystalline.

选区电子衍射证实了SnO2是多晶态.

Invisible braces are made of translucent polycrystalline alumina ( TPA ).

隐形牙套的材料是半透明多晶体氧化铝 ( TPA ).

Lattice parameters are the important crystal structural parameters of polycrystalline materials.

晶胞参数是多晶材料晶体结构的重要参数.

Polycrystalline diamond coatings for tools are laid down using chemical vapor deposition.

工具用的复晶钻石涂层,则是使用化学气相沉积法制造的.

Polycrystalline diamond has many advantageous physical properties.

金刚石烧结体具有许多优异的物理机械性能.

Polycrystalline iron fiber is a novel magnetic material, which can be used widely in industry.

多晶铁纤维是一类新型磁性材料, 应用十分广泛.

Nowadays, the infection of quantum effects of polycrystalline silicon is also investigated.

近期, 多晶硅中量子效应对器件性能的影响也被研究.

Polycrystalline silicon is an aggregation of small silicon crystals.

多晶硅是细小硅晶的集合体.

Transgranular fracture. Fracture of polycrystalline materials by crack propagation through the grains.

多晶材料裂纹穿过晶粒扩展而断裂.

Intergranular fracture. Fracture of polycrystalline materials by crack propagation along grain boundaries.

多晶材料裂纹沿着晶界扩展而断裂.

Process of enhancing wear resistance of polycrystalline sintered compact has been studied.

研究了提高多晶烧结体耐磨性的方法.