缩并

Acetophenone cylic ethylic ketal was synthesized by using acetophenon e and glycol as reactants,and rare-earth solid superacid SO 2- 4-La 3 +/TiO 2 as c atalyst.Factors affecting the product yield were investigated.

以稀土固体超强酸SO2 -4-La3 +/TiO2 为催化剂，苯乙酮和乙二醇为原料催化合成苯乙酮环乙二缩酮，并考察了影响反应的因素。

The effect of the gasifier structure on gasification process and result was considered in this model.

利用建立的模型，对等径结构、颈缩结构和渐扩结构3种形式的分级气化炉进行了计算，得到温度、气体组成及其体积分数、碳转化率等参数沿气化炉炉膛的分布情况，并和连续气化的结果进行了对比。

The paper mainly studies the catalytic effect of crown ether for Darzens glycidic ester condensation of aromatic aldehydes with ethyl chlorocetate in mixed sovent system.

本文报道了在混合溶剂中冠醚催化作用的 Darzens 酯缩合反应，并合成了四个芳族缩水甘油酸酯类化合物。

Portal vein pressure, size of spleen the collateral circulation of portal vein and the fluctuation of hematocyte counts were measured and recorded at the preconcerted time.

实验犬25只，随机分为A组(正常组，n=5)、B组(对照组，n=10)、C组(实验组，n=10)。A组仅予以剖腹探查，B组予以门静脉主干部分结扎建立模型，C组则通过门静脉主干部分结扎附加3周后脾静脉缩窄及其属支结扎的方法建立模型，建模后术前及术后每周动态观察两组动物血象的变化，B、C组在预定时间点(术后第5、第9周)分别随机选择5只动物开腹观测门静脉自由压、脾脏大小、门体侧支循环形成情况，并切取脾脏行组织病理学检查，此外，术前及术后预定时间点了解骨髓增生情况变化。

The anesthesia emphasis of the descending aortic coarctation operation is controlled-hypotension and suitable hypothermy. The complication of acute congestive heart failure, paraplegia and acute renal failure must be prevented.

降主动脉缩窄手术的麻醉处理重点在于控制性降压和适当的降温，并应严防急性心衰、心跳骤停、截瘫、急性肾功能衰竭等并发症的发生。

The article introduces the improvement of traditional jointcutting technology of cement concrete pavement and the application of inequally spaced skew contraction joint in the construction of cement concrete pavement .

介绍对传统的水泥砼路面切缝技术进行了改进，采用不等距斜缩缝技术，并在水泥砼路面施工中的应用。

Methods To dispose concerned data with unified software and scale how hard malignancy do harm to the health of the residents of Jinwan District with SPYLL and Interceptive death rate.

应用统一软件对有关资料进行处理，并采用标化减寿率、截缩死亡率指标来衡量恶性肿瘤对金湾区居民健康的危害程度。

The article introduces the anti-tumor and other pharmacologic effects of the isocoumarin s, reviews the methods of synthesizing isocoumarin s, and places an emphasis on introducing and comparing such methods of synthesizing syntheticroutes of dihydro isocoumarin s as ozone oxidation, organic metal sythesis, catalytic oxidation and so on.

介绍了异香豆素类化合物在抗癌和其他药理方面的作用，综述了异香豆素类化合物的合成方法，着重介绍其中的二氢类异香豆素化合物的臭氧氧化法、金属有机合成法、催化氧化法、分子间成环缩合法等合成方法，并进行了比较。

Mg-Al oxide catalysts were prepared by co-precipitation method, used ammonia as the precipitating agent. The catalytic performances of these materials were investigated in the gas-phase Aldol condensation of acetone to isophorone. The structure and surface properties of the catalysts were characterized by means of XRD, XPS, ICP, TG-DTA and TPD.

采用共沉淀法，以氨水为沉淀剂制备了一系列具有不同Mg/Al摩尔比的镁铝氧化物催化剂，考察了它们在丙酮气相缩合反应中的催化性能，并通过XRD，XPS，ICP，TG-DTA和TPD等手段对催化剂的结构和性质进行了表征。

In this thesis, we describe a facile and economical synthesis of-abscisic acid from keto-isophorone and 3-butyn-2-ol through ketalization, oxidization, Witting-Horner reaction, reduction with chromium sulfate and other steps in 13% total yields. Compared to the previous routes, the starting materials are more commercially available and cheaper and the synthetic process is more easily controlled in our method, but the yield of this route is still to be improved.As to isostere principle, cyclopropyl and methyl vinyl are a couple of isostere.

本论文设计并完成了一条全新的外消旋脱落酸(1)全合成路线，从廉价的工业原料氧化异佛尔酮和丁炔醇出发，经过缩酮化反应、氧化反应、Wittig-Horner反应、CrSO_4选择性还原反应以及水解等七步反应实现了脱落酸的全合成，总产率达13％，与以往路线相比，该路线所用试剂廉价、合成路线简单，但产率有待提高。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。