共查询到20条相似文献，搜索用时 109 毫秒
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本文提出了一种简便、快速直接测定海水Co的石墨炉原子吸收光谱方法。研究了几种不同的有机基体改进剂及石墨炉升温程序对消除基体干扰的效果。管壁原子化、酒石酸为基体改进剂、积分吸收测量、一次进样20μl(或多次进样以提高灵敏度)以及严格控制狭缝宽度在0.4nm可以获得最佳分析结果。海水Co的检测限(3σ)为0.1μgL~(-1),特征质量mo为4.6pg/0.0044A.S。11个海水样品及4个河水样品的平均回收率为98％,平均相对标准偏差为4.6％。 相似文献
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本文以硝酸钯作海水砷的基体改进剂,研究了硝酸钯加人前后对海水砷原子化行为的影响。结果表明:硝酸钯的存在可抑制海水基体的干扰。据此建立了石墨炉原子吸收直接测定海水的分析方法,并获得海水和双蒸水中碑的特征质量值为23pg,实际水样检测限为0.62μgL~(-1)(3σ计,20μl),用标准校正曲线法计算水样分析结果与标准加人法比较相当接近,测量精度最大为3.8％。 相似文献
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本文试验了几种以石墨炉原子吸收光谱法测定海水Mn的有机基体改进剂。柠檬酸及柠檬酸三铵消除海水基体干扰的效果最好。二次蒸馏水及海水Mn的特征质量(mo)及检测限(D.L.)是一致的,表明干扰已消除。用Z3030仪器获得的m_0及D.L.值分别为3.5pg及0.078μg/L;而用Z180—80仪器获得的分别为2.6pg及0.048μg/L。回收率范围为96～105％。 相似文献
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试验表明用石墨炉原子吸收光谱法直接测定海水Pb时,抗坏血酸—HNO_3是消除海水基体干扰的有效基体改进剂。样品从石墨管壁原子化,不同商标的热解涂层石墨管效果不一。分析结果通过“质控海水”和“极谱分析法”的验证,结果是满意的,回收率在95～99％范围。对含Pb lμg/L以内的海水可直接测定。 相似文献
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石墨炉原子吸收光谱法测定海水中痕量镉的几种基本改进剂的选择 总被引：1，自引：0，他引：1
林能文 《福建师大福清分校学报》2006,(2):44-48
本文介绍利用石墨炉原子吸收法测定海水中的镉,通过加入几种基体改进剂消除共存物质的干扰,该方法快速、准确、方便,对试样的回收率为95～104%之间。 相似文献
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石墨炉原子吸收光谱法测定水中的微量铅 总被引：4，自引：0，他引：4
应用磷酸二氢胺作基体改进剂,钽涂层石墨管原子吸收光谱法测定水中的微量铅.方法准确、灵敏度高,重现性好.方法的检出限为0.21μg·L-1,回收率为96.5%～102.2%,相对标准偏差为1.5%～4.2%. 相似文献
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微波消解石墨炉原子吸收法测定蔬菜中的痕量镉 总被引：1，自引：0，他引：1
采用微波消化技术，以自吸背景校正方式，在硝酸介质中，NH4H2PO4和Mg(NO3)2混合物为基体改进剂，直接用石墨炉原子吸收法测定了蔬菜中的镉，并研究了最佳的实验条件．该法在0-6μg／L范围内呈良好的线性关系，检出限为0．16μg／L，回收率为96．4％-103．8oA．用于蔬菜中痕量镉的测定，结果满意。 相似文献
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石墨炉原子吸收法测定自来水中的有害元素铅 总被引：1，自引：0，他引：1
采用石墨炉原子吸收光谱法,水样处理后加入基体改进剂,测定水中有害元素痕量铅.实验优化了石墨炉原子吸收光谱法的测定条件.重点讨论了铅的灰化温度、原子化温度以及基体改进剂的选用对铅测定结果的影响,结果表明,以磷酸二氢盐、钯盐为基体改进剂可提高灰化温度,消除样品中的钙、镁、钠等复杂基体的干扰,相对标准偏差为2.23%,回收率为94.0%-102.0%,具有良好的精密度和回收率.方法简便快速、结果准确. 相似文献
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王尚芝 《雁北师范学院学报》2007,23(1):34-35,42
采用石墨炉原子吸收光谱法测定了中成药中微量镉，考察了基体改进剂及其它实验参数对测定结果的影响．在优化实验条件下，采用标准加入法测定，方法的检出限为0．0614ng／ml，精密度为4．78％，回收率为99．2％～103．4％． 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 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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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 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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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献