黄丹中铜含量的荧光猝灭测定法

用荧光猝灭法对黄丹中铜离子进行测定,考察实验条件的影响及干扰情况,建立测定的最佳条件,为测定黄丹中微量铜离子提供一种灵敏、快速的新方法。     

柿竹园某尾矿区嗜铜微生物的初步研究

目的:通过对采集的6层样本(A、B、C、D、E、F)进行嗜铜菌筛选培养及铜离子测定,为筛选嗜铜菌提供依据.方法:利用嗜铜菌筛选培养基和火焰原子吸收光谱法对所采集的样本进行嗜铜菌初筛和铜离子含量测定.结果:共培养出13种嗜铜菌,其中有菌丝的8种,有芽孢的2种,短杆的4种,球状的1种;铜离子含量由第1层至第6层依次递减;初步鉴定为8个土壤微生物菌属.结论:筛选的13种嗜铜菌为嗜铜金属修复工程菌研究奠定了基础,对重金属污染地区的土地复垦和生态植被恢复具有指导意义.     

二价铜离子在分析化学中的应用

铜(Ⅱ)离子的外层电子构型为3S^23P^63d^9。它的3d，4S、4P电子亚层有能级较低的空轨道．可以接受N、O、S等原子所提供的孤电子对，而形成共价型或配位型极性键的化合物，且有特征的颜色。据此，可以利用某些有机试剂对二价铜离子进行鉴定和含量测定。     

铜试剂胶束光度法测定胆矾中的铜含量

在非离子表面活性剂ＯＰ存在下，研究了铜（Ⅱ）与铜试剂的配位显色反应性能。结果表明，在实验条件下铜量在０－４０ｕｇ／２５ｍｌ围内服从比耳定律，其表观摩吸光系数ε４６０为２．１１×１０４Ｌｍｏｌ－１ｃｍ－１。本法用于胆矾中铜含量的测定，结果与碘量滴定法一致。     

柠檬酸铜配合法测定柠檬酸含量

根据铜离子与柠檬酸钠形成稳定配合物的原理，用甲基红作指示剂、氢氧化钠作滴定剂的酸碱滴定法测定了柠檬酸的含量。     

pH值对黄河水中铜,锌含量影响的研究

用火焰原子吸收法研究ＰＨ值对黄河水中铜、锌离子含量的影响，结果表明，ＰＨ值越低，水中金属离子含量越高。回收率在９４％－１０４％，相对标准偏差小于２％。     

催化动力学光度法测定饲料中痕量铜的研究

研究了铜 (Ⅱ )离子在酸性介质硫酸中和氯化十六烷基吡啶条件下 ,铜 (Ⅱ )催化抗坏血酸还原邻甲氧基苯基重氮氨基偶氮苯 .建立了测定痕量铜离子的新方法 ,结果比碘量法测定铜(Ⅱ )离子效果更好     

铜离子选择电极测还原糖鉴别蜂密纯度

用铜离子选择电极测定蜂蜜与 SB试剂反应后剩余的二价铜离子 ,计算出蜂密中还原糖的含量。该方法准确、快速、简便 ,是一种可行的蜂蜜鉴别方法     

浊点萃取法对沱江内江段水体铜离子含量测定

利用浊点萃取--分光光度计法测定水体中兼量铜离子.在pH=7的条件下,以表面活性剂曲拉通100(Triton X-100)作为萃取剂,利用铜离子与1-(2-吡啶偶氮)-2-萘酚(PAN)乙醇溶液产生显色反应的性质,在550nm的渡长下采用分光光度法测定水样中的痕量铜离子的含量.测定内江市区段沱江沿岸中铜离子含量与国家标准比较,各采样点超标150%以上.     

铜试剂胶束光度法测定胆矾中的铜含量

在非离子表面活性剂op存在下，研究了铜（II）与铜试剂的配位反应性能，结果表明，在实验条件下铜量在0－40ug/25ml围内服从比耳定律，其表观摩吸光系数ε460为2．11×10^4Lmol^-1cm^-1，本法用于胆矾中铜含量的测定，结果与碘量滴定法一致。     

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.