超声辐射下Mg-K-10-MgCl2-H2O体系中芳香醛的还原偶联反应

超声波引发下，用Mg-K-10-MgCl2-H2O体系还原芳香醛，在室温反应3-4h得到产率为20～60％的邻二醇产品。     

以四氮杂大环镍为催化剂的B—R化学振荡体系研究

报道了一种以四氮杂大环镍（II）配合物为催化剂的B—R化学振荡体系[NIL]（ClO4）2－KIO3-H2SO4-CH2（COOH）2—1-1202,其中L为5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四-4,11－二烯。对反应体系的影响因素进行分析,探讨了反应机理。     

NO3^-对B-Z振荡反应的影响及其在分析中的应用

研究了NO3^-对B-Z化学振荡反应的影响．结果表明：NO3^-的加入明显改变该振荡反应的诱导期,且诱导期的改变值△tin与所加入NO3^-的浓度有良好的线性关系,线性范围3．334×10^-5-1．000×10^-3mol·L^-1,相关系数为0．9959．NO3^-CH2（COOH）2-KBrO3-H2SO4-Ce（SO4）2振荡体系诱导期表观活化参数Ein为109．1kJ·mol^-1．     

NH4NO3-H2SO4混合液中NO3-测定方法分析

对用分光光度法测定亚铁还原NH4NO3-H2SO4混合液中NO3-的方法进行了讨论,旨在建立一个测定NH4NO3-H2SO4混合液中NO- 3的快速方法,运用于生产工艺的控制分析.     

左旋多巴对四氮杂大环铜配合物催化的化学振荡反应的影响

四氮杂大环配合物催化的振荡反应引起了人们的广泛兴趣,这是因为此振荡反应更接近于生物振荡体系。选择了一种四氮杂大环铜配合物催化的化学振荡体系：NaBrO3-苹果酸-H2SO4[CuL]（ClO4）2,其中L为5,7,7,12,14,14-六甲基-1,4,8,11,-四氮环杂十四-4,11-二烯,研究了左旋多巴对该振荡体系的影响。结果表明,左旋多巴的加入明显改变了振荡体系的周期和振幅．且浓度与振幅的改变值△A呈现良好的线性关系,线性范围为：9．90×10^-6-2．44×10^-4,相关系数为0．9933。同时对加入左旋多巴后体系的反应机理进行了初步探讨．     

NH4NO3-H2SO4混合液中NO3ˉ测定方法分析

对用分光光度法测定亚铁还原NH4NO3-H2SO4混合液中NO3ˉ的方法进行了讨论，旨在建立一个测定NH4NO3-H2SO4混合液中NO3ˉ的快速方法，运用于生产工艺的控制分析。     

硫酸钠-过氧化氢-水三元体系液固相平衡的神经网络模拟

将神经网络应用于液固体系相平衡,建立了283K和288K下Na2SO4-H2O2-H2O三元体系的BP神经网络模型,网络的训练结果偏差平方和分别为7 2×10-5和4 1×10-5,网络模型仿真的结果与实验值能够很好的吻合,所建能较好地描述该体系液固相平衡的溶解度数据.     

用N_(235)从HCI—H_2SO_4混酸溶液中萃取铜(∏)的研究

某厂生产化学品排放的含铜废液中 ,含铜 8-12克 /升 ,废酸的浓度高达 5 -6mol/dm3。我们先用N2 35 萃取铜 ,提取铜后的废液供钢铁厂作酸洗液。本文从HCI -H2 SO4混酸溶液对N2 35 萃取铜的条件、萃取平衡反应以及萃合物组成等进行了研究。     

三烷基钇配合物合成及在催化Tishchenko反应中的应用

烷基稀土金属配合物由于其较高的催化活性,近年逐渐成为人们的硏究热点。而正由于其不稳定,易发生配体再分配或β-H消除等反应.若要使其穏定,则需采取其他措施。在无水无氧的条件下,利用2-(二甲胺基)苄基锂盐LiR(R=CH2C6H4-NMe2-o)与三氯化钇反应制得相应的三烷基钇配合物YR3。配合物YR3能够有效地催化Tishchenko反应,反应条件温和,产率中等。     

测定蔬菜中铅含量的前处理方法的比较

本文通过大量试验对测定蔬菜中铅含量的三种前处理方法——HNO3-HClO4消化法、H2SO4-H2O2消化法、微波干灰化HNO3-HClO4法进行比较研究，证明微波干灰化HNO3-HClO4法具有氧化完全，药品用量少，无污染等优点。     

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!     

胡主席在印度,我却在中国

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.