共查询到20条相似文献，搜索用时 62 毫秒
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郭庆宇 《中小学实验与装备》1998,(4)
氢化漆酚是漆酚侧链带有不饱和结构的有力证明。把漆酚溶入乙醇后，在铂海绵存在下，用氢还原成为氢化漆酚。氢化漆酚是针状的结晶体，熔点为５８～５９℃。氢化漆酚目前已被用作为色谱分析中漆酚的基准物。因为氢化漆酚有这个特点，当它与有关的化合物作用，会呈现一系列... 相似文献
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邵建兵 《泰州职业技术学院学报》2010,10(3):36-37,71
目的研究建立氢化可的松洗剂及霜剂的含量测定方法。方法采用旋光法测定氢化可的松洗剂及霜剂的含量。结果氢化可的松在3．5—12．0mg·mL-1浓度范围内,旋光度与浓度呈良好线性关系,回归方程Y=3．3481X-0．03685（r=0．9999）,平均回收率：氢化可的松洗剂为100．3％,RSD为O．52％;氢化可的松霜剂为99．7％,RSD为O。75％,（n=5）。结论本法操作简便准确,可作为两种制剂的质量控制方法。 相似文献
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吴瑛 《岳阳职业技术学院学报》2012,27(5):83-88
以硝基苯的氢化为模型反应,对常压下Pd/C催化氢化进行了新的探索。考察了反应时间、反应温度、催化剂用量、通氢气速度以及溶剂种类等因素对硝基苯氢化的影响,为合成氧化偶氮苯和亚硝基苯提供新的途径。 相似文献
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田新衍 《湖北第二师范学院学报》2014,31(8)
西门子法生产多晶硅过程中副产大量的四氯化硅.近几年来,企业为了降低成本、采用冷氢化工艺将四氯化硅转为三氯氢硅循环再利用.本文重点讲叙冷氢化应用技术研究与探讨. 相似文献
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氢化还原反应是化学工业中应用极为广泛的一类化学反应类型。在我们日常生活中所使用的化学制品的生产过程中,人们治疗疾病时所使用的药品及发展生产的大批农药的生产合成中都要出现氢化还原反应。例如: 用于麻醉的药品“普鲁卡因”是由对硝基甲苯做为原料开眙合成的,其中重要的一步就是硝基氢化还原反应转为胺基。 相似文献
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卢金飙 《新疆教育学院学报》1996,(1)
本文从过渡金属元素的d电子结构,过渡金属π络合物的结构,分子前线轨道理论及氢化反应机理等方面来说明不饱和键的氢化反应需用Ni、Pd、Pt等过渡金属作催化剂的本质. 相似文献
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我科于1988～1989年应用本院新制的氢化可的松涂膜治疗神经性皮炎、湿疹收到满意效果、报告如下: 一、制剂和方法处方:氢化可的松 0.5,薄荷 2.0,樟脑 2.0,乙醇 2.0,胶棉液加至 100.0。制法:取樟脑、薄荷脑、乙醇同置于干燥密闭容器内、待樟脑、薄荷脑溶解后加入氢化可的松摇匀,再加入成膜材料胶棉液至全量置密闭容器内冷暗处备用。 相似文献
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本文综述了三(正)丁基氢化锡在有机合成中的化学选择性还原和区域选择性加成。 相似文献
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含氮杂环化合物是有机化合物中的一类重要物质,它是构成生物碱的基础骨架。如何构建C-N键以合成含氮杂环一直是从事生物碱全合成以及合成氮杂环药物研究的有机合成工作者关注的热点问题。本文对氢化吲哚类及氢化喹啉类氮杂环的合成方法进行综述介绍。 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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Rajesh Kanoi 《海外英语》2007,(1):52
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer. 相似文献