选择反应

A method using α methylstyrene as raw material to prepare β methylene phenethyl alcohol,a new rose flavor ,by chlorination,esterification and saponification was studied.

对α 甲基苯乙烯经氯代、酯化、皂化合成新型玫瑰香料β亚甲基苯乙醇的方法进行了研究，选择PTC1作为相转移催化剂，当m∶m (NaAc·3H2 O)∶m (PTC1 )=1 。0 0 0∶0 30 0∶0 0 2 4时，80℃下反应 6h ，产率为 67 3%。

At present, the city has chosen the 30 kinds of green plants mainly noise, absorption and scattering properties of the test, found the crown of large, heavy branches of trees, such as cypress, camphora, Ligustrum, Photinia, coral and so on, by Noise excellent skills; oleander, octagonal gold, small wax, shrubs and other mosquito-mother, but also the noise of the reactive barrier, which will provide noise reduction mature green residential experience.

目前，该市已选择了30种主要绿化植物噪音，吸收和散射特性的测试，发现树冠大，重型分行的树木，如柏树，香樟，女贞，石楠，珊瑚等，噪声优秀技能；夹竹桃，八角金，小蜡，灌木及其他经蚊子母亲，而且噪音屏障的反应，这将提供降噪成熟绿色住宅的经验。

The easy hydrolytic degradation polyester was synthesized in the batch reaction vessel of 6 m 3. Hydrolytical properties of EHDPET can be controlled at will by selecting suitable hydrolytic conditions. By spinning EHDPET and PET (or PA6) in the mass ratio of 15~25/85~75 on Hills bicomponent spinning equipment, sea\|island bicomponent fibers which have good physicomechanical properties and processing performance were obtained.

在6m3 间歇式反应装置上合成了易水解聚酯，选择适宜条件，EHDPET 的水解性能可以得到随意控制，将合成的EHDPET 与PET以 15～25／85～75 质量比在 Hills 双组分复合纺丝机上进行复合纺丝，得到以EHDPET为海组分，以PET（或PA6）为岛组分的海－岛型复合纤维；该复合纤维物理性能良好，用该复合纤维织造的机织物和针织物，其纺织加工性能均良好。

METHODS:Treatment records of 1100 teeth with acute or chronic pulpitis or chronic apical periodontitis were compared.

选择患急、慢性牙髓炎和慢性根尖周炎 80 0例 110 0个患牙，随机分为两组，对照组 5 14牙采用常规根管治疗术即两次法，实验组 5 86牙采用一次法进行根管充填，观察各组术后近期临床反应。

Since complex constitutes of raw material, various reactions and phases are involved in the process of mesophase evolution, we suggest that a given carbonaceous mesophase product should be manufactured by selecting raw materials and setting pyrocondensation conditions according to the specific requirement of the product, so that products with the best structure and performance could be obtained.

通过讨论指出，由于炭质中间相涉及的原料种类多样，热缩聚制备过程中涉及的反应、物相复杂，因此，在制备特定性能的产品时，应针对产品的特定性能要求来选择原料、设定热缩聚条件，以制得具有最佳结构和性能的产品。

Based on the observation that mammalian cells appear to be dependent on methylation for activation, SAHH has recently been selected as an attractive specific target for design of agents for immunosuppression, antiviral, treatment of atherosclerosis and Alzheimer's disease.

鉴于SAHH在调节生物体转甲基化反应中的核心地位，它已被选择作为多种新药研发的重要靶点，包括免疫抑制剂、抗病毒药、防治动脉粥样硬化和阿尔茨海默病药物。

The research developments in synthesis and application of silicotungstate with Keggin-type structure and its derivants used as catalysts in epoxidations of alkenes were reviewed.

综述了近十年来新型 Keggin结构硅钨酸盐及其一系列衍生物催化剂的合成及其在选择氧化反应中应用的研究进展。

Generally choose to fail off valve,(should be noted that in general to the water to remove dissolved oxygen which will be added hydrazine for processing, it would SATELLITE 6 Hao alloy or other alloys of similar adverse reaction, so it is best not to use 316 + STELLITE surfacing approach to valve parts, can be directly use 416 stainless steel material).

一般阀门选择为故障关，(需要注意的是一般给水中为消除溶解其中的氧会加入联胺进行处理，它会对SATELLITE 6号合金或其它的类似合金产生不良反应，所以最好不使用316+STELLITE堆焊的方法处理阀内件，可直接选用416不锈钢材料)。

Ii The Ti/C ratio had better be in accord with the stoichiometrical relation of TiC.

该图的建立，对于在实际生产中选择合理的反应工艺参数以及预测和控制原位TiCp/Fe复合材料的组织均有指导意义。

The main postoperative complications were anterior uveitis and posterior synechia of the iris. Conclusion Trabeculectomy with MMC may be the procedure of choice in medically unresponsive cases of APACG.

小梁切除术联合MMC是药物治疗无反应的急性原发性闭角型青光眼治疗可供选择的手术方法。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。