共查询到20条相似文献,搜索用时 78 毫秒
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X射线荧光光光谱分析 总被引:3,自引:0,他引:3
评述了我国在2007~2008年X射线荧光光谱,包括质子激发的X射线光谱的发展和应用,内容包括仪器、软件、仪器改造、仪器维护和维修、基础研究和分析方法研究及其应用. 相似文献
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X射线衍射法定量分析蓝晶石样品 总被引:1,自引:0,他引:1
提出了应用X射线衍射法定量分析蓝晶石样品。将粒径10~15μm的蓝晶石粉末置于模具中,制成厚度为0.2mm的样片。取经提纯的蓝晶石和纯石英,按不同比例配成11个校准样品用于制作工作曲线,每一样品中加入相同量的刚玉作为内标以校正基体干扰。方法用于蓝晶石地质样品分析,所得测定结果与理论值相符。 相似文献
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X射线荧光无标半定量分析奶粉微量元素 总被引:3,自引:0,他引:3
采用X射线荧光光谱半定量分析方法同时检测了奶粉样品中微量元素含量,以奶粉中主要营养成分含量为依据,模拟计算其平均分子式作为平衡项处理。结果表明,采用模拟的平均分子式作为平衡项处理,测定结果与给出的标准值吻合。该法样品处理简单,分析速度快,无需建立校准曲线,方法的准确度符合分析的需要。 相似文献
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神经群结构,算法与X射线荧光光谱分析研究 总被引:4,自引:0,他引:4
研究了一种多组分型神经群网络结构,根据多元体系各变量间的内在规律,可在神经网络中由相互间具有紧密联系的一些神经元的集合形成群结构,采用这种全连接方式的神经群网络结构,减少了连接权重,剔除了噪音,从而增强了模型稳定性,提高了X射线荧光光谱预测准确度,显著增加了神经网络的外推预测能力,降低了训练模型所需的标样数。 相似文献
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铌酸钾锂的X射线荧光光谱分析 总被引:2,自引:0,他引:2
提出了一种用X射线荧光光谱分析铌酸钾锂中Li_2O,K_2O和Nb_2O_5的方法.采用deJongh校正方程,将Li_2O当作消去组分,所得Li_2O的结果与ICP-AES法一致.同时建立了非破坏分析校正曲线. 相似文献
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探讨了我率导数光谱(d^nT/dλ^n)与吸光度导数光谱(d^nA/dλ^n)的关系,并讨论了用d^nT/dλ^n作定量分析的可行性及其产生分析误差的原因以及最佳测量条件。 相似文献
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Harold Basch 《Chemical physics》1975,10(1):157-166
The energies and intensities of satellite bands in the X-ray photoelectron spectrum of formaldehyde have been calculated using molecular wave functions obtained from a combination of multi-configuration self-consistent field theory and configuration-mixing formalism. The intensities of monopole allowed shake-up processes have been obtained from the sudden approximation formula whose derivation by an alternative route is detailed. It is found that the satellite spectra of carbon and oxygen hole states are predicted to differ substantially; giving insight into the atomic orbital character of the molecular orbitals concerned. The significance of the appearance of satellite bands on a quantitative analytical use of X-ray photoelectron spectroscopy is pointed out. The possibilities and condition for the appearance of monopole forbidden valence shell shape-up processes is discussed. 相似文献
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建立了一种小波软阈值法(STWPLS)同时测定铜(Ⅱ)、镉(Ⅱ)、锌(Ⅱ)方法。此法结合多分辩分析和软阈值法改进除噪质量。通过最佳化,小波函数,低频收缩截止水平(L)和阈值法类型分别选为Daubechies8,3和HYBRID。并将此法与偏最小二乘法(PLS)做了比较。 相似文献
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Edberg A Soeria-Atmadja D Bergman Laurila J Johansson F Gustafsson MG Hammerling U 《Journal of chemical information and modeling》2012,52(5):1238-1249
Structurally different chemical substances may cause similar systemic effects in mammalian cells. It is therefore necessary to go beyond structural comparisons to quantify similarity in terms of their bioactivities. In this work, we introduce a generic methodology to achieve this on the basis of Network Biology principles and using publicly available molecular network topology information. An implementation of this method, denoted QuantMap, is outlined and applied to antidiabetic drugs, NSAIDs, 17β-estradiol, and 12 substances known to disrupt estrogenic pathways. The similarity of any pair of compounds is derived from topological comparison of intracellular protein networks, directly and indirectly associated with the respective query chemicals, via a straightforward pairwise comparison of ranked proteins. Although output derived from straightforward chemical/structural similarity analysis provided some guidance on bioactivity, QuantMap produced substance interrelationships that align well with reports on their respective perturbation properties. We believe that QuantMap has potential to provide substantial assistance to drug repositioning, pharmacology evaluation, and toxicology risk assessment. 相似文献