共查询到20条相似文献，搜索用时 718 毫秒
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用分光光度法研究了氯冉酸与水的荷移反应，确定了反应条件。并对某些食品香料中的微量水进行了测定，与国标方法共沸蒸馏法相比，结果令人满意。 相似文献
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采用两种紫外分光光度计(UV2450和755B型)对紫拟青霉色素溶液进行吸光度测定.通过比较分析两种紫外分光光度计的测定值,可知在吸光度值0.3-0.7范围内,普通教学用紫外分光光度计755B测定结果与UV2450无明显差异. 相似文献
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紫外—可见分光光度计在实际工作中应用广泛.在使用过程中需要对各项性能指行逐项进行检查、校正.光度计的主要性能指标有波长准确度、波长重复性、吸光度准确性、吸光度重复性、基线的稳定性和平直性、光度线性范围、分辨率等.需要用不同的方法进行检测.以保证分析的准确性. 相似文献
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奚长生 《湖南城市学院学报》1993,(5)
自1951年B、chance研制成第一台双波长分光光度计以来,无机多组份体系分光光度测定方法,取得了显著的进展,发展了双波长分光光度法,三波长分光光度法,双显色双波长分光光度法,导数分光光度法,组合导数分光光度法,本文试就借助于仪器的输出信息,消除重叠光谱带的干扰,同时测定无机多组份体系的分光光度方法,作一简要的评述。 相似文献
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用分光光度计测出不同浓度KCN反应溶液的吸光度,绘制出标准工作曲线。将待测水样在酸性条件下进行蒸馏,取蒸馏液使之与氯胺T、异烟酸－巴比妥酸试剂反应,比色分析,定性判断水样中是否含有氰化物;再用分光光度计测出其吸光度,在标准工作曲线上查值,经过计算即可行出水样中氰化物的含量。 相似文献
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奚长生 《湖南城市学院学报》1993,(6)
多组份分光光度同时测定中的数学解析方法,随着计算机在分析化学领域的应用,得到了迅速的发展,新的数学解析方法不断出现,已应用于多组份分光光度同时测定的数学解析方法不断地完善和发展,本文拟从数学解析的角度出发,就若干主要的多组份分光光度同时测定中的数学解析方法,作一简要的评述。 相似文献
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《赣南师范学院学报》1986,(Z2)
本文研讨了统计光度误差,统计光度误差的定义是△C/C=1/(-㏒T_(平均))㏒[(T_(平均))/((T_(平均))-|ts/n~(1/2)|)]当它对T％作图,可得分光光度法统计光度误差曲线,实验原始数据通过曲线拟合以PC—1500A型计算机绘出统计光度误差曲线,并详细地研讨其应用。诸如应用于评价分光光度计,比较仪器,以及确定分析方法最小随机误差时光度测量的浓度范围。 本文根据统计光度误差原理,提出用于光度法检量线进行实验作图,结果与回归作图相同。 相似文献
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卢卯旺 《衡阳师范学院学报》1998,19(6):29-31
讨论了场源的电（磁）荷、角动量、旋转电荷和磁短对引力红移效应的影响。结果表明,电（磁）荷、角动量和磁矩均使这种效应减弱,旋转电（磁）荷使这种效应增强。 相似文献
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《海外英语》2007,(5):10-11
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? 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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唐芳 《读与写:教育教学刊》2008,5(6)
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. 相似文献