共查询到20条相似文献，搜索用时 62 毫秒
1.
表面活性剂增敏催化光度法测定痕量亚硝酸根 总被引：1，自引：1，他引：1
基于在稀硫酸介质中溴代十六烷基吡啶 (CPB)对亚硝酸根 (NO-2 )催化溴酸钾氧化碘曙红褪色反应的增敏作用 ,建立了测定NO-2 的表面活性剂增敏催化动力学光度法 .由于加入增敏剂 ,灵敏度显著提同 .lgA0 /A值与NO-2 含量在 0～ 1.0 μg/mL范围内存在线性关系 ,检出限量为0 .0 6 μg/ml.方法用于水样、蔬菜中痕量亚硝酸根的测定 ,结果较好 相似文献
2.
宁明远 《邵阳学院学报(社会科学版)》2000,(5)
基于Ag 催化过硫酸盐氧化铍试剂Ⅱ (C2 0 H2 1O15S4 N2 Na)的褪色反应及动力学条件 ,建立了测定痕量银的催化光度法 .该法检测范围为 0～ 4 μg/ 10ml的Ag ,检测下限为 0 .0 2 μg/ 10ml.经巯基棉分离富集 ,可用于合金及岩矿中痕量银的测定 ,回收率在 91.8%～ 10 4 %之间 相似文献
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催化动力学光度法测痕量铁 总被引：1，自引：0，他引：1
研究了在硫酸介质中 ,铁 (Ⅲ )催化抗坏血酸还原 3,3′—二磺酸基联苯氨基重氮偶氮苯而褪色的反应 ,从而建立了一种催化动力学光度法测定痕量铁的新方法 .本方法的测定范围为 0～ 3 0 μg/ 2 5ml,检出限为 4 3× 1 0 -1 0 g/ml.用本法测定发样、奶粉中的痕量铁 ,结果满意 . 相似文献
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在pH6～ 8范围内 ,PAN -S与Ni(Ⅱ )形成 1∶1的红色络合物 ,最大吸收峰在 5 35nm ,镍量在 0～ 2 5 μg/2 5ml符合比尔定律 ,摩尔吸光系数为 2 .84× 10 4。掩蔽干扰离子后 ,可以直接测定钢铁中的镍。 相似文献
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研究了钼蓝法测磷新体系 ,磷—钼酸铵—联苯胺的显色反应体系中 ,产生两种蓝色产物 ,其加和作用具有明显的增敏效果 ,磷的最低检测浓度为 0 .12 μg /ml 最大吸收波长 710nm ,表观摩尔吸光系数 2 .10× 10 4 L·mol- 1 ·cm- 1 磷在0～ 2 0 μg/ml范围内符合比尔定律 方法简单、快速、准确 . 相似文献
6.
新显色剂4-甲酰-2-磺酸基苯基重氮氨基偶氮苯的合成 总被引：1，自引：0，他引：1
报道了一种新型的三氮烯类偶氮染料的合成方法及其与 Cd( )的显色反应 .实验表明 ,在Triton X- 10 0存在下的弱碱性介质中 ,试剂与镉 ( )形成 2 :1的红色络合物 ,最大吸收系数为 2 .1× 10 5L· mol- 1 · cm- 1 ;镉含量在 0～ 2 5 μg/ 2 5 ml范围内遵守比耳定律 .可直接用于废水中微量镉的测定 . 相似文献
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研究了横向加热石墨炉原子吸收光谱法测定人发中铜含量条件.结果表明:以1%的硝酸介质,干燥温度为110℃,灰化温度为900℃,原子化温度为1900℃,铜浓度在0～0.28μg/ml有良好线性关系,r为0.9992,方法检出限为0.013μg/g,用于实际样品分析效果良好,回收率为94.8%～104.2%.在同一体系中能满足FAAS法对Fe,Zn,Ca,Mg的连续测定. 相似文献
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气相色谱法测定水环境中酚的研究 总被引：1，自引：0，他引：1
本文建立了毛细管气相色谱法测定水质中酚含量的方法 ,对测试条件进行了系统的讨论。该方法的相关系数为 0 .9995,检出限围 4 .0× 1 0 -5μg/ml,相对标准偏差为 1 .1 %～ 6.6% ,加标回收率为 89.1 %～ 96.0 % ,该法与国标法比较 ,其测定结果无显著性差异 ( P>0 .2 0 )。该法灵敏度高 ,测定结果准确可靠 ,操作简便。 相似文献
9.
湛海粼 《重庆第二师范学院学报》2003,16(6):50-52
在 pH2 .0～ 6.0的条件下 ,曲利本蓝 (TB)与硫酸新霉素 (NEO)发生反应生成蓝色离子缔合物 ,最大显色波长位于 680nm ,最大褪色波长位于 5 88nm ,摩尔吸光系数 (ε)分别为9.1 5× 1 0 3和 2 .87× 1 0 4 L·mol- 1 ·cm- 1 ,线性范围在 0～ 1 3.0 μg/ml至 0～ 1 6.0 μg/ml之间 .若用双波长叠加法测定 ,则ε值可达到 3.79× 1 0 4 L·mol- 1 ·cm- 1 .该方法用于实际样品的测定 ,结果满意 . 相似文献
10.
目的 :建立马齿苋中二羟基苯丙氨酸的含量测定方法。方法 :毛细管电泳法 ,熔硅毛细管 (5 8.2cm× 75 μmi.d .,有效长度 5 0 .6cm)。结果 :本方法最佳分离条件为采用含 15mmol·L- 1SDS和 30mmol·L- 1磷酸盐作为缓冲液 (pH =9.0 )。线性回归方程Y =0 .0 2 7+3.6 5X ,r=0 .999,线性范围 0 .0 98～ 3.4 6mg/ml。样品中二羟基苯丙氨酸的含量为 0 .76 % (g/ g) ,RSD=2 .18%。结论 :此方法样品处理简单 ,操作快捷方便 ,适合于中药分析测定。 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
14.
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
17.
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
18.
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