共查询到20条相似文献,搜索用时 570 毫秒
1.
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
2.
J. Hakala R. Rodríguez-Guzmán V. -V. Elomaa T. Eronen A. Jokinen V. S. Kolhinen I. D. Moore H. Penttilä M. Reponen J. Rissanen A. Saastamoinen J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2011,47(10):1-12
Direct mass measurements with typical uncertainties of 1-10keV have been performed for the first time for ten neutron-rich isotopes 102, 103Y , 108Nb , 111Mo , 113, 114Tc , 116Ru , 119Rh , and 121, 122Pd . The obtained mass data compared with the 2003 atomic-mass evaluation shows systematic overestimation of binding energies far from stability. The relationship between two-neutron separation energies, nuclear structure and shape changes has been investigated by comparing the experimental data with a theoretical calculation based on the Hartree-Fock-Bogoliubov approximation using modern energy density functionals. 相似文献
3.
S. Y. Larsen 《Few-Body Systems》2002,31(2-4):91-96
I will outline three-particle calculations, and results, in one dimension [1–4] with delta-function interactions, in two
dimensions [5–11] for square wells and in three dimensions [12] with delta shells. The presentation will be that of my own
work, obtained together with colleagues. The initial approach is that of expansions of the wave function in terms of hyperspherical
adiabatic functions, usually deduced from hyperspherical harmonics.
Received October 29, 2001; accepted for publication November 23, 2001 相似文献
4.
Total energies for the six known polymorphs of plutonium metal have been calculated within spin and orbital polarized density-functional theory as a function of lattice constant. Theoretical equilibrium volumes and bulk moduli correspond well with experimental data and the calculated total energies are consistent with the known phase diagram of Pu. It is shown that a preference for the formation of magnetic moments, increasing through the alpha-->beta-->gamma phases, explains their position in the ambient pressure phase diagram and their anomalous variation of atomic density. A simple model is presented that establishes a relationship between atomic density, crystal symmetry, and magnetic moments which is universally valid for all Pu phases. 相似文献
5.
原子吸收光谱法检测肝癌、肝硬化、肝脓肿患者血清中Cu、Zn、Cr、Mn、Mg微量元素含量 总被引:7,自引:0,他引:7
应用原子吸收光谱法检测了肝癌、肝硬化、肝脓肿患者血清微量元素的含量,发现肝癌和肝硬化患者血清内Cu含量明显高于正常对照组和肝脓肿组(P〈0.001,Cr、Mn含量明显低于正常对照组(p〈0.001)和肝脓肿组,肝脓肿患者血清内微量元素含量与正常对照组无显著性差异(p〈0.05)。结果表明:肝癌、肝硬化患者Cu、Mn、Cr存在代谢异常。 相似文献
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ICP—AES法直接测定锡锭中的As,A1,Bi,Cd,Cu,Fe,Pb,Se,Sb,Zn 总被引:4,自引:0,他引:4
以电荷耦合器件为检测器的全谱直读等离子体光谱仪直接测定锡锭中As、A1、Bi、Cd、Cu、Fed、Pb、Se、Sb、Zn十种杂质元素的含量。该方法简便、快速且具有比化学法更低的检出限,加标回收试验结果不明,回收率为92%-105%,RSD均小于1.5%。 相似文献
8.
ICP—AES法测定铁矿中铝,钙,镁,锰,钴,铜,钠和钾 总被引:3,自引:0,他引:3
本文研究了ICP-AES法测定铁矿中铝,钙、镁、锰、钴、铜、钠和钾的方法。对仪器工作参数,共存元素的光谱干扰和基体效应干扰进行了探讨。采用向标准系列中加入铁基空白溶液建立工作曲线,试样经酸处理后即可直接测定。本方法获得了良好的回收率(95~103%)和变异系数(0.5~1.3%,n=11),同原子吸收法进行比对试验,结果一致。 相似文献
9.
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
10.
We report on the development of a fiber-based laser transmitter designed for active remote sensing spectroscopy. The transmitter uses a master oscillator power amplifier (MOPA) configuration with a distributed feedback diode-laser master oscillator and an erbium-doped fiber amplifier. The output from the MOPA is frequency-doubled with a periodically poled potassium titanium oxide phosphate crystal. With 35 W of single-frequency peak optical pump power, 8 W of frequency-doubled peak power was achieved. The utility of this single-frequency, wavelength tunable, power scalable laser was then demonstrated in a spectroscopic measurement of diatomic oxygen A band. 相似文献
11.
Stopping powers of several metalic elements have been measured using a silicon detector. The present results are decisively lower than the data of Anderson et al.. The deviations are statistically significant. But Nara data agree well with the table of Barkas and Berger. 相似文献
12.
Bremsstrahlung isochromats of polycrystalline TiC, ZrC, HfC, VC, NbC, and TaC have been measured at a monochromator energy of 1,008.2 eV. The curves are similar to those of the pure metals, but show a secondary structure caused by the chemical binding of metal and carbon. The experimental results are compared with density-of-states calculations. Together with XPS-measurements, they allow to derive the widths of the total conduction bands of the carbides, which are compared with thed-band widths of the pure metals and with band structure calculations.Dedicated to Prof. K. Ulmer on the occasion of his 65th birthday 相似文献
13.
ICP-AES同时测定铝合金中Fe,Si,Cu,Mg,Mn,Ni,Zn,Ti,Cr,Sr等杂质元素 总被引:13,自引:0,他引:13
本文通过基体干扰和操作条件的试验研究,分别用基体匹配法和干扰系数法校正基体干扰和待测元素间的干扰,建立了以氢氧化钠溶样,ICP-AES同时测定铝合金中铁、锰、铜、锌、镁、钛、硅、镍、铬、锶等杂质元素的方法。方法快速、简便、可靠,回收率93%-102%,适用于进出口铝合金的快速检验。 相似文献
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The geometrical structure, stability, magnetism, and electronic structure of bimetallic clusters AuM2 and Au2M2, where M are 4d transition metal elements, are investigated systematically by using the first-principles method based on density functional theory. The calculation results show that there is a large amount of low-energy isomers with the very similar structure. AuM2 and Au2M2 clusters display dramatic magnetism. The magnetic moment of the 4d element is either enhanced or weakened with respect to th... 相似文献
16.
J.K. Yakinthos P.F. Ikonomou T. Anagnostopoulos 《Journal of magnetism and magnetic materials》1978,8(4):308-312
Magnetic properties of nine RE2Au compounds have been studied in fields of up to 19 kOe in the temperature range 4.2K–300K. It has been found that all compounds are paramagnetic at room temperature except Gd2Au. The compounds with Pr, Nd, Ho, Er and Tm exhibit Curie-Weiss behaviour with paramagnetic moments in close agreement with those expected for the free RE3+ ion. The moment of gold was found to be zero. The compounds with Pr, Nd, Tb, Dy, Er and Tm are antiferromagnetic at low temperatures. It appears that Ho2Au is ferromagnetically ordered below 4.5 K. No evidence for magnetic ordering was found for Y2Au. The compound with Tb exhibits metamagnetic behaviour. 相似文献
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18.
L. Lomova 《Radiation measurements》1995,25(1-4):179-180
One of the possible methods of increasing the sensitivity of track Aghal detectors by replacement of AgCl with AgBr is presented. 相似文献
19.
F. E. Close 《Contemporary Physics》2013,54(2):67-78
A particle about 50% more massive than a proton, with positive charge, positive strangeness and positive baryon number, has been claimed in several experiments. Such a particle cannot be made from three quarks; its minimal configuration requires four quarks and an antiquark and it became known as a ‘pentaquark’. This article summarizes the evidence and concentrates on the theoretical interest that it has excited into the nature of correlations among quarks and antiquarks in the strong interaction limit of QCD. 相似文献
20.
Electrical explosion of wires (EEW) is a promising method for nanopowders preparation and insensitive explosives ignition. Plasma radiation plays a key role in the ignition process while little attention has been paid on this phenomenon before. This letter introduces optical emission behaviors of electrical explosions for nine materials in air, Helium, and Argon with the SWE-2 platform. Experimental results indicated that the light intensity for non-refractory metals decayed rapidly after the discharge ended. In contrast, for refractory metals, the emission continued to increase and lasted for a long period after the discharge ceased. As for spectra, the emission consisted of line and continuous spectra. With the atomic number increased, the density of lines grew rapidly, leading to a “continuous” appearance. 相似文献