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本文介绍厂用碳酸钡作缓冲剂测定二氧化锆中Mg、Fe、AI、C。、Ti、Hf、Si杂质元素的发射光谱方法。该方法直接压样于普通电极中,简便、快速。取得了满意的结果。 相似文献
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发射光谱法测定高纯银中微量金、铂、钯、铑、铱、锑、铅、铋、铁、铜、镍、铬、铝和锌 总被引:1,自引:0,他引:1
本文研究了贵金属标准溶液除氯离子的有关问题,解决了高纯硝酸银中贵金属等杂质元素的标样配制,以硝酸银直接压样于普通电极中直流电弧激发,可测定99.0~99.99%的高纯银,该方法简便、快速、准确。 相似文献
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碰撞池ICP-MS测定大米中Ca、Mn、Fe、Cu、Ni、As、Se、Sr、Cd、Ba和Hg的研究 总被引:1,自引:0,他引:1
建立碰撞池ICP-MS测定大米中Ca、Mn、Fe、Cu、Ni、As、Se、Sr、Cd、Ba和Hg的分析方法。采用微波消解方法消解样品后直接进行ICP-MS分析,并采用碰撞池技术消除质谱干扰,混合内标溶液校正基体干扰和漂移。方法的精密度均小于5%,回收率为85%—113%,并对标准物质(大米)GBW 10010GSB-1进行方法验证,获得较满意的结果。本法快速、简单,能满足大米中常量、微量、痕量金属元素同时测定的分析需求。 相似文献
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提出了直读光谱法同时测定无铅焊料中铅、镉、铜、银、铋、砷、锑和铁的方法,该方法准确度高、精密度好、测定速度快,已在生产控制过程中得到应用. 相似文献
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采用内标-脉冲雾化进样法,建立了微量体液的ICP-AES分析方法。对内标的选择,分析信号与进样量的关系和分析标准曲线等方面进行了研究,测定了微量体液样品中的Ca、Mg、Fe、Zn、P、Mn、Cu、Pb、Sr等元素的含量,获得了较满意的结果。 相似文献
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P. Kula A. Spadło J. Dziaduszek M. Filipowicz R. Dąbrowski J. Czub S. Urban 《Opto-Electronics Review》2008,16(4):379-385
Compounds with moderate and large negative dielectric anisotropy (Δɛ) are very attractive liquid crystal (LC) for vertical
alignment mode (VA). Materials with such properties can be achieved by lateral substitution of a polar group into a mesogenic
molecule. We synthesized some new LC materials with a negative value of Δɛ, a moderately high birefringence (Δn), and a low
viscosity. The mesomorphic and physical behaviour of the novel biphenyls, terphenyls and quaterphenyls fluorosubstituted in
the rigid core and also with fluorinated alkyl and alkoxy chains are investigated. The prepared series of four LC compounds
are promising for new LC mixtures for various applications. Examples of nematic mixtures with Δɛ∼−3.25 will be presented. 相似文献
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R. Stresing D. Lindenberger R. Kümmel 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(2):279-287
Cointegration analysis is applied to the linear combinations of the time series of (the logarithms of) output, capital, labor,
and energy for Germany, Japan, and the USA since 1960.
The computed cointegration vectors represent the output elasticities of the aggregate energy-dependent Cobb-Douglas function.
The output elasticities give the economic weights of the production factors capital, labor, and energy. We find that they
are for labor much smaller and for energy much larger than the cost shares of these factors. In standard economic theory output
elasticities equal cost shares. Our heterodox findings support results obtained with LINEX production functions. 相似文献
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H. ur Rehman M. Springborg Y. Dong 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,52(1-3):39-42
Results of a theoretical study of the properties of Sin, Gen, and SinGen clusters are presented. An approximate density-functional method in combination with genetic algorithms have been used in an unbiased determination of the structures of the lowest total energy. The resulting structural, energetic, and electronic properties are analysed and compared with each other for the different systems. 相似文献
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Density functional theory study of structural,electronic,and thermal properties of Pt,Pd, Rh,Ir, Os and PtPdX(X= Ir,Os, and Rh) alloys 下载免费PDF全文
《中国物理 B》2016,(3)
The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys Pt Pd X(X= Ir, Os and Rh) are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties.We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition. 相似文献
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Alpha particle and deuteron impactL-subshell ionization cross-sections of Ar, Cu, Ge, Br, Zr and Ag have been computed using Vriens’ expressions for ionization
cross-section of atoms due to impact of heavy charged particles. The effects of Coulomb deflection of the projectile and increase
in binding of the target electron in the presence of projectile have been incorporated. Hartree-Fock velocity distributions
for the target electrons have been used in the present calculations. The simple binary encounter approximation model is found
to give results which are in satisfactory agreement with those obtained from experiments and from other theories. 相似文献
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H.F. Zhang 《Journal of Physics and Chemistry of Solids》2010,71(7):976-982
The structural, dielectric, lattice-dynamical, and thermodynamical properties of isotopic lithium hydrides (6LiH, 6LiD, 6LiT, 7LiH, 7LiD, and 7LiT) were investigated within density-functional theory. The atomic structure was fully relaxed and the structural parameters were found to differ by less than 2% from the experimental data. The associated electronic band structure and density of states were also presented. A linear-response approach to the density-functional perturbation theory was employed to work out the Born effective charges, dielectric tensors and phonon frequencies, and thermodynamic properties. The compounds with the heavier Li isotope or H isotope have the lower phonon frequencies; 6LiT is more stable than 7LiT, 6LiD, 7LiD, 6LiH, and 7LiH in the temperature range 0-2700 K. These properties of LiT were predicted for the first time. The results were discussed in terms of the isotope effects on phonon dispersion curves and thermodynamic properties. 相似文献
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M. Alcolea Palafox 《光谱学快报》2013,46(2):379-402
The vibrational frequencies of several silanes H3SiX (X=BH2, AlH2, PH2 and SH) are determined. The infrared and Raman spectra are plotted. Several scale procedures were use to improve the theoretical spectra. The geometric parameters in the planar, staggered and eclipsed structures of these species are fully optimized and compared with ab initio calculations. Basis set effects on the calculated structures are discussed. A few thermodynamic parameters, net atomic charges, dipole moment and energy are also computed. 相似文献
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Miao Zhang Yingli Niu Guangtian Zou 《Journal of Physics and Chemistry of Solids》2008,69(8):2096-2102
The chemical bonding, elastic behavior, phase stability, and hardness of OsB, OsB2, OsC, OsO2, OsN, and OsN2 have been systematically studied using first-principles calculations. The calculation suggests that the chemical bonding in these compounds is a mixture of covalent and ionic components. The structural stability of OsB, OsC, and OsN can be understood in terms of the band filling of the bonding states, and the results indicate that the hexagonal tungsten carbide structure is more stable. The hardness of these osmium compounds is calculated using both ab initio and semiempirical model calculations. Analysis of the ab initio hardness suggested that the large occupations and high strength of the covalent bonds are crucial for a superhard material, and there is no clear connection between bulk modulus and hardness in these osmium compounds. 相似文献
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The ground state dissociation energies of CN, PbF, SiF, SnF, SnS and NBr molecules have been estimated using the empirical electronegativity potential function proposed by Szöke and Baitz. The dissociation energies for these molecules have been found to be 7.9, 3.2, 4.2, 3.2, 3.0 and 2,7 eV respectively and compared with the earlier values. 相似文献
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藻类植物中钙、镁、铁、锰、铜和锌含量分析 总被引:15,自引:2,他引:13
本文采用火焰原子吸收光谱法测定了七种藻类植物中钙 ,镁 ,铁 ,锰 ,铜 ,锌六种元素的含量。结果表明 ,藻类植物中含有较丰富的钙 ,镁 ,铁 ,锰 ,锌元素 ,其含量由大到小顺序为Ca >Mg >Fe >Zn >Mn >Cu ,尤以钙的含量最为丰富 ,铜含量较少。本实验结果为探讨藻类植物作为资源开发利用提供了有用数据。 相似文献