共查询到20条相似文献，搜索用时 62 毫秒
1.
探讨了利用紫外可见分光光度计测定锌-硫氰酸钾-结晶紫三元体系形成的配合物的吸光度值及得到最大吸收时的最佳条件,并利用其测定人发中含有的微量锌。试验结果表明,锌-硫氰酸钾-结晶紫三元体系形成的配合物,在522nm处有最大吸光度值。在522nm处的摩尔吸光系数为ε522 =1.29×105L/mol/cm,检出限量为2.5×10-5mg/mL,在0.5～5.0μg/25mL时符合朗伯-比尔定律,呈线性关系,回收率为98～102%。此方法操作简便、快捷,具有很高的灵敏度,准确度较高,是测定微量锌的较好方法之一。 相似文献
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N-辛基-N＇(氨基对苯磺酸钠)硫脲是新合成的一种显色剂,该试剂极易溶于水而形成无色溶液。在PH3。6-5.2的HAC-NaAC缓冲体系中,试剂与铜(Ⅱ)形成一种稳定的蓝色水溶性配合物,其组成比为Cu(Ⅱ):PT=1:3,配合物的最大吸收位于301.4nm处,表观摩尔吸光系数ε_(301.4)=1.82×10~5L·mol~(-1)·cm~(-1)·Cu(Ⅱ)在0-10μg/25ml服从比耳定律,相关系数γ=0.9996,方法的检出限为3.85×10~(-9)g/ml。本法灵敏度高,选择性好,测定结果准确可靠,将该法不经分离直接应用于合金钢和生物制品中微量铜的测定,均获得满意的结果。 相似文献
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1-（4-硝基苯基）-3-（5-溴-吡啶）-三氮烯的合成及其与铜的显色反应 总被引：1，自引：0，他引：1
报道了1-(4-硝基苯基)-3-(5-溴-吡啶)三氮烯(NPBPDT)的合成及其与铜的显色反应．在NP-10的存在下，pH11．0的Na2B4O7-NaOH缓冲溶液中，该试剂能与铜发生显色反应，铜与NPBPDT形成摩尔比为1：2型的黄色配合物，在440m处有一最大正吸收峰，在540nm处有一最大负吸收．以440nm为参比波长，540nm为测量波长进行双波长测定，表观摩尔吸光系数为1．91×10^5L·mol^-1·cm^-1，铜的浓度在0-12μg／25mL范围内遵守比尔定律．用拟定方法测定铝合金中的微量铜，结果满意． 相似文献
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冯泳兰 《衡阳师范学院学报》1994,(6)
研究了铜（Ⅱ）与邻羟基萘基荧光酮，在阳离子表面活性剂溴化十六烷基三甲铵存在下，NH4Cl－NH3·H2O缓冲介质中在形成紫红色配合物，其最大吸收波长在560nm处，表观摩尔吸光系数为1．06×105l·mol－1·cm－1。Cu（Ⅱ）含量在0～4μg／25ml符合比尔定律。配合物组成：Cu（Ⅱ）：0－HNF为1：2。研究的新方法应用于标准岩石样品中微量铜的测定，结果满意。 相似文献
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本文研究了合成的显色剂(3,4一亚甲二氧基苯甲醛缩氨基硫脲,缩写PTSC)与Cu(Ⅱ)的显色反应,且PTSC与Cu(Ⅱ)形成1:1的黄色配合物在λmax=390nm处摩尔吸光系数为7.2×10~4,铜量在0～20μg/25ml符合比耳定律,适用于矿样中低含量铜的测定。 相似文献
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通过使用荧光光谱法，研究了新合成的化合物2，6-吡啶二甲酰（氨基酸）胺与竞争过渡金属离子及稀土离子的配位性质。发现在pH=2.0-12.0以及溴化十六烷基吡啶存在下，该化合物可以和铜离子形成稳定的配合物，其最大激发和发射波长分别位于310nm和420nm，组成比为2：1(铜离子：配体）。当铜离子的浓度介于1.1μg/ml-32.0μg/ml范围时，配合物荧光强度与铜离子浓度呈良好的线性关系，线性方程为F=0.44757 3.98388CCu^2 (10^-3mol/L）。通过新化合物与铜离子的配位反应，初步考察了新试剂的配位特征。 相似文献
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详细研究了在淡化十六烷基三甲铵（CTMAB）存在下，镓与2，4-二氯苯基荧光酮和F-的显色反应条件和光度性质，在PH6．0的HAc－NaAc缓冲介质中，Ga与试剂形成1：2的配合物，最大吸收峰位于568nm处，表现摩尔吸光系数ε为1．78×105L·mol－1cm－1．Ga含量在0～5μg／25ml范围内符合比尔定律，拟定方法用于地质样品中线的测定，结果满意． 相似文献
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朱彬 《遵义师范学院学报》2000,(1)
用作者合成的嘶试剂5-(8-喳啉偶氮)-2,3-二羟基吡啶作显色剂,以分光光度法测定微量钴,在PH9.3的硼砂缓冲溶液中,配合物的最大吸收波长在624nm处,钴量在0～20μg/25ml范围内符合比尔定律,表观摩尔吸光系数为9.0×10~4L·10mol(-1)·cm(-1)。方法简便、快速,应用于维生素B_(12)和镍盐中钴的测定,获得满意结果。 相似文献
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报道了新显色剂1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯的合成。在pH11.5的Na2B4O7-NaOH缓冲溶液中,TX-100表面活性剂存在下,1-偶氮苯-3-(5-溴-2-吡啶)-三氮烯与铜发生显色反应,生成3:1的红色配合物。配合物的最大吸收波长位于540nm处,表观摩尔吸光系数为8.13×104L.mol-1.cm-1,Cu2 的浓度在0~12.0μg/25mL范围内符合比尔定律。用拟定方法测定石乳花茶和大米样品中微量铜,结果令人满意。 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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Rajesh Kanoi 《海外英语》2007,(1):52
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. 相似文献
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正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse. 相似文献
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《今日中学生》2014,(9)
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between 相似文献
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《重庆大学学报(英文版)》2014,(2)
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof. 相似文献