共查询到20条相似文献，搜索用时 656 毫秒
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废水和底泥中烷基汞的气相色谱法测定 总被引：4，自引：0，他引：4
采用气相色谱-带电子捕获检测器测定废水中的甲基汞和乙基汞．前处理方法采用酸性条件下用苯草取、中性条件下用L-巯基丙氨酸-醋酸钠溶液分离-富集烷基汞，再在酸性条件下用苯反革取提取烷基汞。用气相色谱测定．水样加标甲基汞回收率为93％～97％。RSD为2．18％～2．57％；乙基汞回收率为95％～97％，RSD为1．97％～2．03％． 相似文献
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常征 《安徽技术师范学院学报》2003,17(3):253-256
采用溴酸钾—溴化钾消解法，通过对消解时间、消解温度及盐酸羟胺加入量的研究，得出较为适合的实验条件，可以快速测定水样中的汞，实际样品分析结果满意．RSD％=0．76％～2．7％，CV％=92．8％～101．3％。 相似文献
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薛行爱 《福建师大福清分校学报》2005,(2):9-14
应用AFS-2202a型原子荧光光度计对地表水和海水中的砷、汞联合测定方法进行有苴的研究。通过实验，探讨总结出了合理有效的水样前处理方法和实用测定步骤。并对其最低检出下限、精密度和准确度进行了全面评估，结果表明：该方法具有操作简便、快速、干扰少、灵敏度高等优点，适用于地表水和海水中微量砷、汞元素的联合测定，具有很好的可行性和适用性。 相似文献
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刘桂琼 《黔东南民族师专学报》2004,22(6):47-49
应用AFS-2202E型双道原子荧光光谱法研究了化妆品中汞的测定技术，用温式催化法消化样品，样品处理好后，以KBH42％为还原剂，5％HCI为载流溶液，在优化工作条件下测定汞，汞的最低检出量为0．0125μg／L．用此方法测定化妆品的汞，灵敏度高，准确度好，结果满意． 相似文献
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采用蒸汽发生-原子荧光光谱法，分别在酒石酸和柠檬酸介质中分析山楂叶中砷（As）、汞（Hg）的含量，考察仪器操作条件、反应介质及共存离子等对测定As、Hg的影响．方法检出限为As：0．75μg／kg，Hg：0．034μg／kg． 相似文献
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目的：建立原子荧光光谱同时测定土壤中砷和汞的方法。方法：王水水浴消解土壤样品,在最佳仪器、反应条件下同时测定其中的砷和汞。结果：检出限：As：0.087ng/mL,Hg：0.0065ng/mL。线性范围：As：0ng/mL-20 ng/mL,相关系数0.9999;Hg：0ng/mL-4ng/mL,相关系数0.9996。精密度：测定10ng/mL As、2ng/mLHg混合标准试液得到的标准精密度（RSD）,砷1.6%、汞2.7%。样品加标回收率：As：95.5%-101.4%,Hg：92.5%-102.0%。结论：该方法具有较高的灵敏度、准确度、精密度和较低的检出限,满足了土壤样品中砷和汞的同时测定要求,同时也适合于食品、生物材料等样品的测定。 相似文献
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衬铂平台石墨炉原子吸收光谱法测定环境水样中的痕量汞 总被引：1，自引：0，他引：1
叶平 《宁夏师范学院学报》2000,21(3):14-17
利用衬铂平台石墨炉ＺＥＥＭＡＮ原子吸收光谱法直接测定环境水样中的痕量汞,对衬台石墨炉测汞的最佳测试参数,条件进行系统研究,本方法的灵敏度为普通平台石墨炉的５倍以上,检出限为０．２μｇ／ｌ加标回收率为８８．６－１０９％;相对标准偏差小于４．９５％。 相似文献
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采用断续流动氢化物发生一原子荧光法测定化学实验室的挥发态汞,试验并优化了分析条件．在确定的最佳测定条件下,汞浓度在0．O—12．0ng／mL浓度范围内与荧光强度呈现良好的线性关系,方法的检出限为0．013ng／mL,分析测量值的相对标准偏差（RSD）小于4．3％．测定结果表明,不同操作环境的化学实验室存在着程度不同的汞污染,对师生健康存在潜在威胁,应引起人们的足够重视． 相似文献
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目的:测定注射用牡荆素中的铅、镉、砷、汞、铜等5种重金属元素的含量,探讨牡荆素注射剂重金属的质量控制方法。方法:经微波消解后的注射用牡荆素样品,加入铅、镉、砷、汞、铜等内标元素,ICPMS(电感耦合等离子体质谱)法测定样品中铅、镉、砷、汞、铜的含量。结果:铅、镉、砷、汞、铜的检出限分别为0.4、0.03、0.09、0.04及0.05ng/mL;且线性关系良好(r0.998);铅、镉、砷、汞、铜回收率分别为97.8%、97.2%、104.0%、91.2%和92.8%。结论:本方法操作简便、灵敏度高、专属性好,适用于注射用牡荆素中铅、镉、砷、汞、铜的质量控制。 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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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 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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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 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