多聚甲醛

For the synthesis of NHC precursors, there are also several routes: condensation of glyoxal, amines and paraformaldehyde; alkylation of imidazole or monosubstituted imidazole with alkyl halide; annulation of ortho esters and 1,2-diamines; ring closure of hydrazines or amides with acetic anhydride; reduction of thiones with Na/K in THF.

关于N-杂环卡宾前体的合成途径主要有：乙二醛、伯胺和多聚甲醛的缩合反应；卤代烷与咪唑及其取代咪唑的烷基化反应；原甲酸酯与1，2-二胺的成环反应；肼或酰胺与酸酐的环化反应；用Na/K对环硫脲化合物的还原反应。

Seven days later, the tissue overlying the chiasm was removed to expose the DiI-labeled chiasm for observation under confocal microscope, and the images were analyzed by METAMORPH soft ware.

培养结束后，将脑厚片以4﹪多聚甲醛固定，将DiI颗粒置于视盘。7d后，在手术显微镜下，暴露被标记的视神经纤维，在激光扫描共聚焦纤维镜下观察。

Objective: To compare the clinical effect of dental pulp devitalization with polyoxymethyleni and modified method respectively in two groups of patients with different age.

目的：比较改进多聚甲醛牙髓失活法与传统失活法的临床效果，并观察其在60岁以上老年人的效果差异。

If cells are not fixed with paraformaldehyde, keep the samples on ice and run them immediately after staining is accomplished

如果做好不能及时检测，我们一般是加入等量的2%的多聚甲醛固定，4度冰箱避光贮存。

If cell s are not fixed with paraformaldehyde, keep the samples on ice and run them immediately after staining is accomplished

如果做好不能及时检测，我们一般是加入等量的2%的多聚甲醛固定，4度冰箱避光贮存。

The experimental group was given an operation of cutting infundibulum and the contol group was given an exposure of not cutting the infundibulum.Both groups were raised under similar condition.After surviving for 30 days,the animals were killed and specimens from aorta were taken and observed under light and electron microscope.

实验组行手术切断漏斗，对照组行手术暴露但不切断漏斗，手术后2d，两组动物移至同一条件下饲养，存活30d后用1%多聚甲醛+1.25%戊二醛液从心脏灌流固定，取主动脉作光、电镜观察。

In case of cold that the crystallization is accompanied by generation of side effects paraformaldehyde, and for non-reversible reaction.

如遇冷即结晶，同时伴随有生成多聚甲醛的副反应，且为不可逆反应。

The preparation,amount of promoters used in synthesis of paraformaldehyde with low polymerization degree were studied.

考察了制备低聚合度多聚甲醛的适宜助剂、加入质量分数和效果，并研究了反应时间、反应温度和热空气线速度对制备的PF中醛质量分数和醛收率的影响规律。

In this paper,the expandable phenolic resin was synthesized by paraformaldehyde and phenol in the presence of aqueous NaOH.

以多聚甲醛和苯酚为原料，合成了适用于酚醛膨胀体制备的酚醛树脂。

MOCA is prepared with o-chloroaniline and paraformaldehyde as materials.

以邻氯苯胺和多聚甲醛为反应原料制备MOCA。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。