选择性氯化过程研究现状与发展趋势

本文综述了国内外各种化合物的选择性氯化反应的研究现状与进展.介绍了用氯气、含氯有机化合物和无机氯化物作氯化剂的各种氯化方法,同时涉及新型氯化工艺和反应分离耦合技术的最新发展情况和趋势.     

氯化提金研究和工艺应用现状

本文概述了金的氯化理论和氯化浸出方法原理。根据含金物料，论述了氯化提金工艺的研究和应用，包括氯盐浸出，酸性水溶氯化浸出等工艺，为氯化提金扩大试验与生产提供理论依据和工艺的选择     

液相催化氧化法制备邻羟基苯甲醛

在醋酸钴、醋酸铜复合催化剂作用下，用纯氧液相催化氧化邻甲酚制备邻羟基苯甲醛的过程中，通过反复对比试验得出最佳反应条件为：甲醇：邻甲酚=15：1(摩尔比)，催化剂为邻甲酚质量的1％，搅拌速度500dmin，反应时间10小时，反应温度为80℃，反应压力6kg／cm^2，氢氧化钠：邻甲酚=3．5：1(摩尔比)，收率接近80％。产品纯度可达99．5％，邻甲酚的转化率和选择性都可以达到85％以上。     

2-氨基-6-氯嘌呤的合成

介绍了以五氯化磷为氯化剂合成2－氨基－6－氯嘌呤的方法，并对氯化剂及反应温度的影响进行了初步研究。     

邻苯二甲醛的简易合成工艺

研究了邻二—(二氯甲基)苯在冰乙酸条件下，滴加少量浓硫酸，酸解合成邻苯二甲醛各反应条件的影响；实验结果表明：邻二—(二氯甲基)苯与浓硫酸摩尔比为1：4，反应温度在90—100℃，反应时间为90min，邻苯二甲醛的收率可达92．3％．     

氯化亚砜在有机合成中的应用（Ⅰ）氯化亚砜使有机物氯化

综述了氯化亚砜在有机合成中的氯化应用，重点介绍了使羧酸氯化，去羟基氯化，加成羰基氯化，使活性亚甲基氯化及取代C，N，S，P，Si等原子上基团氯化的反应原理。     

吲哚的合成工艺研究

目的：研究吲哚的合成。方法：以邻硝基甲苯为原料,经羟基化、氢化和环化3步反应合成吲哚。羟基化反应中原料摩尔配比多聚甲醛／邻硝基甲苯为0．9,反应温度为50℃,催化剂用量为5mL,反应时间为90min。结果：在该条件下,邻硝基甲苯的转化率为72．8％,选择性90．9％,吲哚的总收率为58．I％（以邻硝基甲苯计）。结论：原料便宜易得,反应条件温和,收率高,易实现工业化。     

超声波辐射下N-苄基邻苯二甲酰亚胺的合成

在超声波辐射条件下合成了N-苄基邻苯二甲酰亚胺,并且研究了影响反应产率的各种因素。实验得出最佳反应条件为：反应温度80℃,反应时间为30 min,反应产率达到95.3%。产物结构由元素分析、核磁共振氢谱确证。     

稀土邻菲罗啉硫代脯氨酸三元固体配合物的热化学研究

按照文献合成了两种稀土(La,Sm)邻菲罗啉硫代脯氨酸三元固体配合物,通过红外光谱进行表征.利用Hess定理设计了配位反应的热化学循环,并在常压、298.15K下,分别测定了七水氯化镧(六水氯化钐)、邻菲罗啉、硫代脯氨酸及其配合物在溶剂中的溶解焓,根据热化学原理求出了298.15K时两个配位反应的反应焓;并进一步计算出...     

氯化橡胶新工艺及其在涂料中的应用

通过对氯化橡胶的生产反应原理的分析，介绍了氯化橡胶生产工艺方法及新工艺的特点，在分析产品质量性能指标的基础上，叙述了氯化橡胶在涂料中的应用及发展前景。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

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.     

浅谈移民问题

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.     

Sister Carrie, an Adherent of Desires

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.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.