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

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。     

Precision mass measurements of neutron-rich Y, Nb, Mo, Tc, Ru, Rh, and Pd isotopes

Direct mass measurements with typical uncertainties of 1-10keV have been performed for the first time for ten neutron-rich isotopes ^{102, 103}Y , ¹⁰⁸Nb , ¹¹¹Mo , ^{113, 114}Tc , ¹¹⁶Ru , ¹¹⁹Rh , and ^{121, 122}Pd . 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.     

Density-functional calculations of alpha, beta, gamma, delta, delta', and epsilon plutonium

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.     

Results in One, Two, and Three Dimensions, for Delta Functions, Square Wells, and Delta Shells, Respectively

 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     

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

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。     

X射线荧光光谱法测定不锈钢中的组分

用X射线荧光光谱法测定了不锈钢中Si、Mn、P、Cu、Ti、W、Mo、V、Ni、Cr、Nb等11种元素的含量。对磨样条件、准确度和精密度进行了实验,实验表明本方法与化学法所测结果相符。     

ICP—AES法直接测定锡锭中的As,A1,Bi,Cd,Cu,Fe,Pb,Se,Sb,Zn

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％。     

Preparation of AgBr-detectors doped by some chemical elements Bi, Mn, Zn, Sn, Hg, Ca, Al, Ba, Cd and its sensitivity determination

One of the possible methods of increasing the sensitivity of track Aghal detectors by replacement of AgCl with AgBr is presented.     

ICP—AES法测定铁矿中铝,钙,镁,锰,钴,铜,钠和钾

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。     

Narrowband, tunable, frequency-doubled, erbium-doped fiber-amplifed transmitter

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.     

Stopping powers of Al,Ti, Fe,Cu, Mo,Ag, Sn,Ta and Au for 7.2 MeV protons

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.     

Mesomorphic, dielectric, and optical properties of fluorosubstituted biphenyls, terphenyls, and quaterphenyls

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.     

Bremsstrahlung isochromats from transition metal carbides: The cubic mono-carbides TiC,ZrC, HfC,VC, NbC,TaC

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 65^th birthday     

便携式全反射X荧光同时测定清洁水体中多种元素

应用便携式全反射X射线荧光分析仪,以Sc作内标,同时测定清洁水体中的Cu、Zn、Cr、Fe、Mn、Co、Ni,在X射线管电压30kV,管电流200μA,测定时间100s的条件下,运用点滴支持工具,方法检出限为3.1-5.1μg/L.地表水水样分析结果与ICP-Ms法相符,精密度较好,加标回收率在95％-123％之间.     

Magnetic properties of RE2Au compounds (RE = Pr,Nd, Gd,Tb, Dy,Ho, Er,Tm and Y)

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.     

The geometrical structure, electronic structure and magnetism of bimetallic Au_nM_2 (n=1, 2; M=Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd) clusters

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...     

电感耦合等离子体-原子发射光谱法测定苹果浓缩果汁中钾、钠、钙、镁、磷、铁、锌、铜和铅

研究了ICP-AES测定苹果浓缩果汁中K、Na、Ca、Mg、P、Fe、Zn、Cu和Pb的各种条件.样品处理方法简便,避免了待测元素的污染和损失,结果准确.检出限、精密度和准确度均符合质量管理的要求.     

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

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。     

Optical emission behaviors of C,Al, Ti,Fe, Cu,Mo, Ag,Ta, and W wire explosions in gaseous media

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.     

Allergic, dietary, chemical, stress, and hormonal influences in voice abnormalities

Allergic, dietary, chemical, biochemical, stress, and hormonal abnormalities have long been recognized as important factors in both abnormalities of the voice and in the general health of the professional vocalist. In recent years objective methods have become available to evaluate and treat allergic, dietary, and chemical abnormalities and to better understand the effects of stress and hormonal variations. Assessment of allergic disease is efficient and cost effective through the use of in vitro testing techniques combined with skin end point titration. This provides highly specific and objective results and leads to accurate planning of desensitization treatment. This form of treatment can be especially beneficial in the prevention of recurrent laryngitis. An accurate nutritional history provides evidence of food sensitivities that can lead to cyclical allergic-like vocal symptoms that can be prevented with the use of elimination diets and the judicious use of desensitization therapy. An adequate knowledge of the potential effects of chemical sensitivities will assist the patient in the avoidance of provocative chemical exposures. An in depth evaluation of biochemical abnormalities and a specific assessment of the nutritional status must be considered to evaluate the underlying causes of long-standing general health problems that can affect the voice. Likewise, hormonal variations are not only important in their direct effects on the vocal mechanism but in their cyclical effects on the patient's basic biochemical balance. Lastly, stress, which has long been related to problems in professional performance, is only now being fully studied to determine its actual biologic influences and these must be related to the causes of voice disturbances. Understanding all these influences and planning a rational and efficient evaluation of these potential problem areas are imperative in the complete care of the patient with voice abnormalities.