聚甲醛

Main connections are methenyl ether linkage and methenyl. From the end of heat preservation to the end of whole reaction, main reaction was polycondensation. In general, there were three types reaction among melamine modified UF resin, urea-formaldehyde system, melamine-formaldehyde system and melamine-urea-formaldehyde system.

保温反应结束直到整个反应结束，缩聚反应为主要反应类型，三聚氰胺改性脲醛树脂中存在着3种反应体系：尿素甲醛的反应体系、三聚氰胺甲醛反应体系和三聚氰铵尿素甲醛共缩合反应体系。

The adsorption behaviour of chemically different superplasticizers, such as melamine formaldehyde sulphite polycondensate,β-naphthalene sulfonate formaldehyde polycondensate and polycarboxylate, on early hydrating cement phases was studied. For this purpose, pure ettringite AF(subscript t, monosulfate AF(subscript m and syngenite were prepared. The adsorbed amount and zeta potential of early hydration products were measured.

制备了钙矾石AF(下标 t、单硫型硫铝酸钙AF(下标 m和钾长石类单矿物，并研究了三聚氰胺磺酸盐甲醛缩聚物、β-萘磺酸盐甲醛缩合物及聚发酸盐等几种化学成分不同的超塑化剂在其早期水化颗粒表面上的吸附行为。

Experiment finds that melamine formaldehyde resin could reduce the ramie fiber's water absorption.But it usually has low storage stability.For improving the storage stability,the property of Melamine formaldehyde resin is modified by polyvinyl alcohol.

实验发现，三聚氰胺甲醛树脂可降低苎麻纤维的吸水率，但三聚氰胺甲醛树脂存放稳定性差，加入聚乙烯醇进行改性可显著改善三聚氰胺甲醛树脂的贮存稳定性。

We are also the world's largest producer of acetyl products, including acetic acid, vinyl acetate monomer and polyacetal and a leading global producer of high-performance engineered polymers used in consumer and industrial products and designed to meet highly technical customer requirements.

公司在其主要产品市场上拥有首屈一指的市场地位，是世界上最大的乙酰基产品制造商之一，产品包括醋酸、醋酸乙烯和聚甲醛，公司在聚合物领域内也具有世界领先地位。

The main products are SF-1 (as the base plate of the middle sintering Copper Balls powder, surface modified PTFE); SF-2 (plate as the base of the middle sintering Copper Balls powder, surface modified POM); JDB (For brass, bronze, iron-based body, inlaid solid lubricant); dual-metal (steel as the base for the various models of the surface of copper); production of various enterprises have also filled with PTFE, the curve of bearings, bearing powder metallurgy, by Chun-for the Pistons, Piston Ring, ethylene tetrafluoroethylene ring, ring.

主要产品有SF-1（钢板为基体中间烧结铜球粉，表面为改性聚四氟乙烯）；SF-2(钢板为基体中间烧结铜球粉，表面为改性聚甲醛)；JDB（为黄铜、锡青铜、铸铁为基体，镶嵌固体润滑剂）；双金属（钢板为基体表面为各种型号铜）；企业还生产各种填充四氟带、曲线轴承、粉末冶金轴承、减震器活塞、活塞环、四氟乙烯密封圈、环。

To investigate whether apoptosis is one of the mechanism for cell death in spiral ganglion cells and organ of Corti cells of guinea pigs'cochlea induced by ciSPLatin.

最后一次给药后24小时内处死动物、取材，分别多聚甲醛、戊二醛固定或快速液氮冻存，均取左侧耳蜗。

aim: to investigate the changing pattern of apoptosis and proliferation in the development of rat olfactory bulb.

胚胎14 d，新生1 d (postnatal day， p1)，p20及成年大鼠各10只，取嗅球以40 g/l多聚甲醛固定，石蜡包埋，连续切片。

Reaction of citric acid with paraformaldehyde gave anhydromethylene citric acid with a yield of 63%;the reaction of compound with acetic anhydride gave the corresponding anhydride with a yield of 87%;the esterification of compound with lauryl alcohol gave anhydrocitric acid monoester with a yield of 76%.

将等浓度的柠檬酸和多聚甲醛加热，反应生成柠檬酸缩醛环酯，产率为63%；与乙酸酐反应得到相应的柠檬酸酐，产率为87%；与月桂醇酯化，生成产物，产率为76%；用二氧六环做溶剂，将与等浓度的碱进行开环反应，生成柠檬酸月桂醇单酯，产率为83%。

A new train of thought of copolymerising modification of the boron phenolic resin was applied and a new resin contained allyl was synthesized through allyl phenol, phenol, boric acid and polyformaldehyde.

运用硼酚醛树脂共聚改性的新思路，利用烯丙基苯酚、苯酚、硼酸、多聚甲醛等合成出结构中含有烯丙基活性基团的可与其它含不饱和双键树脂发生共聚反应的新型硼酚醛树脂，表征了它们的物理性能和结构。

David Heber at the Center for Human Nutrition, David Geffen School of Medicine, University of California Los Angeles, found that POM Wonderful 100% Pomegranate Juice tested higher in overall phenolic content and antioxidant activity than red wine and Concord grape, blueberry and orange juices.

研究中，为首的国宝博士赫柏在人类营养研究中心的大卫格芬医学院，加州大学洛杉矶，发现聚甲醛美好的100 ％，石榴汁测试，在更高的整体酚含量和抗氧化活性比红酒和康科德葡萄，蓝莓和橙果汁。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。