季相

The synthesis of benzyl benzoate from sodium benzoate and benzyl chloride by phase transfer catalysis process is studied in the article.

由苯甲酸钠和氯化苄通过相转移催化法合成了苯甲酸苄酯，考察了几种季铵盐类相转移催化剂的亲核取代反应性能。

The purpose of this paper is to synthesize some phosphonium salts with PPh3 and some chiral quaternary ammonium salts with L-Valine. And we also use L-Valine and L-Phe-OMe to synthesize a new type catalyst —2,5-diketopiperazine , the simplest compound of cyclo-peptide.

本文利用廉价易得的三苯基磷和手性L-缬氨酸作为起始原料，合成了几种普通季鏻盐和手性季铵盐，并且利用L-缬氨酸与L-苯丙氨酸甲酯反应，合成了一种新型的相转移催化剂——2，5-二酮哌嗪环类的化合物。

The aim of this thesis is to synthesize some new chiral quaternary ammonium salts and bis-quaternary ammonium salts from the popular material------Chloramphenicoland abietic acid, and then we used these chiral quaternary ammonium salts in some substitution reactions and addition reactions in order to research their catalytic action and asymmetric induction.

本文利用廉价易得的手性物质——氯霉素和去氢枞酸为初始原料，合成了几种新的季铵盐类手性相转移催化剂，扩大了手性相转移催化剂的来源，并把它们应用于取代反应和加成反应，以探讨其催化机理和不对称诱导效应。

Plant community ; life form biological type ; layering ; horizontal distribution ; seasonal aspect of community ; succession ; prima succession ; second succession ; clima

植物群落；生活型；成层现象；水平分布；群落季相；演替；初级演替；次级演替；顶极

In this Ph. D. dissertation, reverse microemulsion method was fully used infabricating and modifying polyacrylamide with functional and high-relative moleculeweight. The copolymerization of 2-acrylamide-2-methylpxopanesulfonic acid, fluorescent monomer 4-methoxy-N-(2-N\', N\'-dimethylamino ethyl)naphthalimide alkyl chloride quaternary ammonium salt, fluorescentmonomer 4-(N\'-methyl-1-piperazinylallyl)-N-butyl-naphthalimide chloride quaternaryammonium salt, Cationic monomer dimethylethylammonium bromide and hydrophobical monomer octadecylacrylate with acrylamide and properties of the copolymers werestudied. The interaction between five polymers and Al_2O_3(012) crystal surface have beensimulated by Materials Studio 3.0 program package, binding energies and non-bondinteraction energies and deformation energies have also been acquired.

本文以制备具有较高相对分子质量和功能型PAM为研究目的，将反相微乳液法运用到其制备及改性的有关环节，通过反相微乳液聚合工艺，将几种改性功能单体2-丙烯酰胺基-2-甲基-丙磺酸、荧光单体2-(4-甲氧基-1，8-萘二甲酰亚胺基)-乙基二甲基烯丙基氯化铵、荧光单体4-(N'-甲基-1-哌嗪基)-N-丁基-1，8-萘烯丙氯季铵盐、阳离子单体丙烯酰氧乙基-二甲基-乙基溴化铵和疏水单体丙烯酸十八酯与AM共聚，制备AMPS改性PAM、荧光示踪型PAM、阳离子单体DMB改性PAM和OA改性PAM等四类不同功能单体改性PAM，并研究其应用性能。

Not only the city afforests requests the city to be green, moreover must be artistic, thus the affor

城市绿化不但要求城市绿起来，而且要美观，因而绿化植物的配置就显得十分重要，与环境在生态适应性上要统一，又要体现植物个体与群体的形态美、色彩美和意境美，充分利用植物的形体、线条、色彩进行构图，通过植物的季相及生命周期的变化达到预期的景观效果。

However remarkable impacts were observed in the plantation in terms of community physiognomy,community structure,species composition,species richness,and biomass accumulation.1 Planting trees made community structure simple.Betula alnoidis plantation had three layers including a dominant arbor layer,a complex and well developed shrub layer and a poorly developed vine layer.The arbor layer contained few species and had a single layer.The mountain rain forest had 4 layers including the dominant arbor layer,shrub layer,grass layer and vine layer.The vine layer was well developed and very rich in species composition,and the arbor layer contained as many as 38 species that could be grouped into 3 layers.2 Sequenced by the important value,main species for the plantation and the nature forest were totally different,and the plantation had one dominant species while the nature forest contained many dominant species.3 Planting trees changed the community physiognomy.

但是人工种植西南桦林对群落的季相外貌、群落的结构、物种组成、物种丰富度以及生物量等方面有较大的影响。1人工造林使得群落结构简化，西南桦人工林的层次结构有3层，以乔木层占优势，并且有种类多而发达的灌木层，同时，藤本植物欠发达，但是乔木层树种单一，明显仅有一层；山地雨林的层次结构有4层，以乔木层占优势，还有灌木层、草本层和藤本植物，藤本植物种类多，十分发达；乔木层树种丰富，可达38种，乔木层还可分为3层。2人工造林较大程度地改变了群落的物种组成，根据重要值的大小排列，人工林和天然林的主要物种组成已经完全不同；并且人工林单优树种明显，而天然林就含有较多的优势树种。3人工造林改变了群落的外貌。

The effects of diluents and inorganic ions in the aqueous on the interfacial properties of BODMAC were studied.

季铵盐BODMAC在不同萃取体系中的界面性质本部分内容系统地研究了稀释剂性质、水相无机离子等因素对季铵盐BODMAC界面性质的影响。

This paper reviews the mechanism of the phase transfer catalytic reaction according to the different compositions of catalytists, including quaternary ammonium salts,polyethylene glycols and grown ethers as well as application of the PTC in Organic synthesis , such as the reaction of,nucleophilic substitution,addition,condensation,oxidation-reduction and so on.

综述了在不同催化剂结构下所遵循的相转移催化反应机理，包括季铵盐类、聚乙二醇类及冠醚类催化机理，以及相转移催化在有机合成中的应用，如亲核取代反应、加成反应、缩合反应、氧化还原反应

By the way, when the moon is at first quarter phase, it is also at eastern quadrature – or 90 degrees east of the sun.

顺便，当月亮在第一个季相时，他也会处于东方正交，或者太阳东部90度。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。