首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 921 毫秒
1.
改进了过氧化氢催化分解实验的实验装置。  相似文献   

2.
组合、优化中学实验室常见的玻璃仪器,完成了在常压、酒精灯加热条件下的合成氨反应装置的设计.该实验装置还能用以完成氨的催化氧化、二氧化硫的催化氧化等通常实验室较难完成的实验.改进实验操作简单、用时少、效果好、成功率高.  相似文献   

3.
在现行版实验的基础上,对其他关于乙醇在铜催化下与氧气反应生成乙醛实验进行分析归类,并且提出和设计了新的乙醇在铜催化下与氧气反应生成乙醛的实验的简易装置.  相似文献   

4.
过氧化氢催化分解实验的改进   总被引:2,自引:0,他引:2  
改进了过氧化氢催化分解的实验装置,从而改善了数据处理方法,无需测量反应完全后放出氧气的体积V∞。  相似文献   

5.
针对教材中乙醇催化氧化实验方案的不足,通过查阅相关文献,对该实验方案进行了优化,用具支U形管、注射器、干燥管等实验用品,设计出了一套乙醇催化氧化及产物验证的一体化实验装置.改进后的实验现象明显,对乙醇催化氧化产物的检验更准确与全面,且为课堂教学和实验改进提供了新的思路.  相似文献   

6.
中学化学教材中的演示实验多为装置简单、操作简便、现象明显的实验,但大多没有考虑到药品节约及尾气处理等问题。通过实践研究,对几个与铜有关的实验进行改进,解决了浓硫酸与铜反应的实验中的尾气处理问题;使铜锌原电池中的负极不再产生干扰实验现象的气泡;让乙醇的催化氧化实验在封闭的环境中进行,避免了让师生吸入有毒的乙醛。  相似文献   

7.
采用洗耳球鼓入空气的方法成功地解决了产物的量和产物能否顺利进入检测体系的问题,自制了一种方便的鼓气装置,可将教材中的乙醇催化氧化的演示实验改为学生分组实验。实验现象明显,操作简单、安全性强,能取得良好的实验效果。  相似文献   

8.
催化氧化是乙醇的重要性质。章从反应原理、实验用品及实验步骤方面对四种乙醇催化氧化实验方案进行了设计和评价。  相似文献   

9.
李锋 《考试周刊》2009,(28):168-169
本文通过对《机制工艺学》中原始差复映实验曲线失真原因的分析,并对其影响因素逐个进行论证,装置改进后的实验曲线与理论曲线基本吻合,实验结果正确、稳定。  相似文献   

10.
为完善教材中乙醇催化氧化的实验方法,将教材中加热方式由酒精灯改为电加热管,乙醇的鼓入装置改为喷雾瓶,用空气甲醛自测盒检验产物。实现了乙醇催化氧化及产物验证的一体化探索,不但降低了实验成本,而且实现了学生分组实验的可重复性。实验现象明显,操作简单,安全性强,能取得良好的实验效果。为化学课堂教学和实验创新提供了有益的参考和启发。  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
汉字倒说     
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   

13.
《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   

14.
王菲 《华章》2007,(12):273-273
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   

15.
钱生钱!     
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   

16.
裴水妹 《华章》2007,(11):196
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   

17.
18.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

19.
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   

20.
现在,我们可以没有面包,没有钱,没有房子,没有车子……但我们唯独不能丢失的是高尚的情操,笃定的信念,还有,满满的希望!  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号