缩并

First, 2 molecules of acetone coordinatedwith aluminum by electrostatic attraction . One atom of hydrogen ofacetone migrated to aluminum because of the pulling of the negativeoxygen of aluminum, and then aldol condensation occured.

该催化反应可以认为是氧化铝分子与两分子丙酮分子发生静电络合作用，然后借助氧原子的负电荷导致脱氢并实现缩合。

Although this is possible with existing PDF format file but instead of making a few button clicks, KeyJnote will just do it in simplified way by able to zoom out the existing page and change to thumbnail view thus making the page search a quick and simple task.

虽然这是可能与现有的PDF格式的文件，而是使少数按钮，点击后，将刚刚KeyJnote这样做简化的方式能够缩小现有的网页，并更改缩略图视图从而使网页搜索快速和简单的工作。

About the calculation of casting weight and module,in this paper,the castings are divided three styles:standard castings used usually castings and complex castings. Different methods have been adopted according to different castings.

在冒口优化设计中，采用了两种计算方法：（1）理论性较强的Ruddle三次方程法，并将 Johns的缩孔形状法结合进去，形成了修正三次方程法，使计算结果准确；（2）实际中应用的经验性较强的热节圆法。

This paper introduced the swirl spinning process and the main components of machine,including combing roller,drafting device,fibers′ funneled transporting device,closed fibers-converging device and swirl twisting device.

介绍闭合式旋流纺的工艺流程及其主要机构，包括梳辊牵伸机构、渐缩式纤维输送机构、闭合式纤维集聚机构和旋流加捻器，并分析旋流纺关键机构——闭合式纤维集聚机构的设计。

The Uniform and beauty shrinkage dot glaze obtained from reasonable selection raw materials,adjustment the formula composition of body and glaze,control of the thickness of glaze applied on the body and the firing temperature.If we take measures on decoration object and method of decoration,it is easy to obtain better shrinkage dot glaze.

并指出只要合理地选用原料，调整好坯釉配方，掌握好施釉厚度和烧成温度，是可以得到均匀、好看、美观的&缩点釉&的；若能在装饰对象和装饰方法上大做文章，可以使这一具有&缺陷功能&的釉种产生更好的艺术效果。

This paper investigates the catalysis of D-72 strong acid cation exchange resin on the synthesis of acetals,and systematically discusses the influence of reaction factors on the catalysis reaction.

研究了强酸性阳离子交换树脂对缩醛合成反应的催化作用，系统地探讨了各反应因素对反应的影响，研究发现，D-72强酸性阳离子交换树脂具有较高的催化活性，并能重复使用。

In comparison with the pure standards and the retention indices RI(subscript s reported in the literature, a total of 302 volatile compounds were identified in Changyu XO brandy, including 30 alcohols, 35 aldehydes and ketones, 20 carboxylic acids, 104 esters, 24 substituted benzenes and derivatives, 14 phenolic derivatives, 14 acetals, 16 furan derivatives, 22 terpenic and norisoprenoidic derivatives and 23 others.

实验先采用液－液萃取方法提取张裕XO级白兰地的挥发性成分，然后将酸性成分与碱性和中性成分分离，再采用柱色谱分离手段将其分离为若干个级分并浓缩，采用气相色谱-质谱、标准品比对、保留指数值比较等方法对分离得到的各级分中的成分进行了鉴定，在白兰地中共鉴定出302种挥发性成分，包括醇30种、醛酮类35种、酸类20种、酯类104种、苯同系物及其衍生物24种、酚类14种、缩醛14种、呋喃类16种、萜烯类22种和其他物质23种。

The neutral/basic fraction was furthermore separated into 4 fractions using silica gel normal phase chromatography, and each fraction was then concentrated and analyzed using gas chromatography-mass spectrometry. In comparison with the pure standards and the retention indices reported in the literature, a total of 302 volatile compounds were identified in Changyu XO brandy, including 30 alcohols, 35 aldehydes and ketones, 20 carboxylic acids, 104 esters, 24 substituted benzenes and derivatives, 14 phenolic derivatives, 14 acetals, 16 furan derivatives, 22 terpenic and norisoprenoidic derivatives and 23 others.

实验先采用液-液萃取方法提取张裕XO级白兰地的挥发性成分，然后将酸性成分与碱性和中性成分分离，再采用柱色谱分离手段将其分离为若干个级分并浓缩，采用气相色谱-质谱、标准品比对、保留指数值比较等方法对分离得到的各级分中的成分进行了鉴定，在白兰地中共鉴定出302种挥发性成分，包括醇30种、醛酮类35种、酸类20种、酯类104种、苯同系物及其衍生物24种、酚类14种、缩醛14种、呋喃类16种、萜烯类22种和其他物质23种。

In the current paradigm of galaxy formation, disk galaxies are assumed to form by the cooling and condensation of baryons within dark matter halos.

目前的星系形成理论认为，盘状星系由暗晕中的重子物质冷却并坍缩而成。

In 1985, for example, he brashly proclaimed that when if the universe stopped expanding began to contract, time would reverse everything that had ever happened would be rerun in reverse.

例如他在1985年草率宣布，如果8 tt t8.com 宇宙停止扩大并开始缩小时，时间就会逆转，凡是发生过的一切事情就会逆时间顺序重演一遍。

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。