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Abstract: The traditional catalyst used in acetal(ketal) synthetic reaction is strong inorganic acid.But there is some limits to its use because of its side reaction,strong erosion and liability to pollute the environment.Molybdophosphoric acid is used as
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文摘:缩醛(酮)合成反应的传统催化剂为无机强酸，但由于副反应多、腐蚀性强和易污染环境等缺点，其使用受到限制.用磷钼酸为催化剂，通过醛(酮)与乙二醇直接反应得到了三种缩合产物.对影响反应的诸因素进行研究,结果表明，用磷钼酸作催化剂，用量小，活性高，产品收率较高，且重复使用性能较好. |
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Abstract: The traditional management pattern of the equipment's outlay under the planning economic system couldn't meet the demands of increasing development .
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文摘:在计划经济体制下形成的传统的设备经费管理模式已越来越不能适应形势发展的需要。 |
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Abstract: The traditional teaching of art asks students to copy without paying attention to the colour languages application so that the student cannot control the colour of art in general.
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文摘:传统的美术教学方法只是让学生无休止地临摹，不重视色彩语言的传授，导致学生无法整体地把握色彩，从而削弱了美术教学的效果。 |
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Abstract: The ultrasonic soldering process of aluminium heat exchangers and a few important factors effecting on the soldering are reviewed.
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文摘:论述了铝热交换器的超声波钎焊工艺及其影响钎焊的几个关键因素。 |
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Abstract: The unique rheology of the lecithin-water s ystem has lead to processing difficulties in the drying of lecithin.
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文摘:水化油脚独特的流体特性导致在浓缩脱水时的困难。 |
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Abstract: The urban commerce of San Francisco has been well-developed thanks to its sound exterior environment and inner drive created by the local government, such as facilitating the transportation network for shopping, developing commercial shopping ce
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摘要：对旧金山政府推动发展交通购物网络商业购物中心、开发旅游变化亮点聚合，努力搭建旅游商业经济架构，为城市商业发展创造了良好的外部环境和内在动力。 |
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Abstract: The urban waterfront region has played an important role in the process of industrial development.
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摘要：城市滨水地带曾经在工业的发展中发挥过巨大的作用。 |
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Abstract: The utilization and the prepartion methods of 2,6-DMN are introduced.The separation and purification processes of 2,6-DMN from coal and petroleum tar are reviewed.
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文摘:本文介绍了2，6-二甲基萘的用途和制备方法；综述了从煤焦油和石油中分离提纯2，6-二甲基萘工艺。 |
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Abstract: The value objective of the construction of CPC at the grass roots level consists of two parts—elementary objective and the advanced objective.
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文摘:基层党组织建设的价值目标可分为基本价值目标和最高价值目标，最高价值目标是培养“四有”新型公民。 |
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Abstract: The various kinds of incineration facilities such as liquid injection incinerator,rotary kiln incinerator,bubbling fluidized-bed incinerator and circulating fluidized-bed incinerator used for treating high concentration of waste organic liquor a
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文摘:介绍了国内外高浓度有机废液的焚烧处理装置，即液体喷射焚烧炉、回转窑焚烧炉、鼓泡流化床焚烧炉和循环流化床焚烧炉，阐述了各种焚烧炉的工作特点，通过比较得出，鼓泡流化床和循环流化床焚烧炉在环保方面具有突出的优点。 |
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Abstract: The water-saving solar hot-water heater is improved.The replacement of the two-position water and vapour valve of the water-saving solar hot-water heater by the two position automatic prot ection valve leads to the transition from hand to automa
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文摘:用自动保护双位阀替代节水太阳能热水器的通水输气两位阀，使节水太阳能热水器从手动保护过渡到自动保护，改进了节水太阳能热水器系统. |
