X-ray k-line absorption spectra of certain transition metals in their binary alloys with metalloids

The experimental results of a study of the characteristic absorption of x-rays by metals of the iron group in a number of their alloys and compounds with metalloids are described. On the basis of the results obtained and previous investigations, a conclusion is formulated on the specific features of the absorption curves for these atomic structures for the corresponding nature of the interatomic bond.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 17–22, August, 1978.     

Resonant soft X-ray fluorescence spectra of molecules

Accepted: 6 March 1997     

激光等离子体软X射线辐射能谱时间分辨测量研究

利用(国内最近研制成功的)带聚酰亚胺膜底衬的金透射光栅与软X射线条纹相机相配合,(在LF11~#激光装置上)使用波长为0.53μm的激光打靶,测量了平面Au靶软X射线时间分辨能谱。测量结果观察到了金等离子体的O带辐射强度随时间增加的现象。文章计算了光栅的衍射效率,并讨论了影响测量谱的几个关键因素。     

类氢硅离子软X射线谱的计算

利用高剥离态类氢离子的势函数模型，计算了类氢Si离子的软X射线谱及 其精细结构，计算结果与实验值进行了比较。     

喷气式Z箍缩等离子体辐射软X射线能谱的研究

研制了一台五通道ROSS-FILTER-PIN软X射线能谱仪，能谱范围为0.28—1.56keV.它由5个连续能段组成，每个能段的起止边由罗斯滤片对(ROSS-FILTERS)的L或K吸收边确定.罗斯滤片对的厚度通过优化计算得到，为了使每个通道的灵敏区外响应(即所测能段外响应)与通道总响应之比最小，在滤片对的第二滤片上镀上了一定厚度的第一滤片材料；为了缩减滤片表面积以增强低能滤片的抗冲击能力及方便滤片加工，能谱仪采用了小探测面积的PIN探测器(1mm²).借助此能谱仪，测量得到了喷气式Z箍缩(Z-pinch)等离子体辐射软X射线能谱的分布，并研究了软X射线产额随箍缩状况的变化趋势. 关键词： Z箍缩等离子体 罗斯滤片 软X射线能谱     

From high-entropy alloys to complex concentrated alloys

High-entropy alloys (HEAs) and related concept of complex concentrated alloys (CCAs) expand the diversity of the materials world and inspire new ideas and approaches for the design of materials with an attractive combination of properties. Here, we present a critical review of the field with the intent of summarizing the principles underlying their birth and growth. We highlight the major accomplishments and progresses over the last 14 years, especially in the discovery of new microstructures and mechanical properties. Finally, we outline the main challenges and provide guidance for future works.     

ICF实验软X光能谱的基函数解谱法

惯性约束聚变实验中,14通道软X光能谱仪是测量软X射线能谱、等效积分温度和辐射能流时间过程的重要诊断设备。基函数法是还原能谱分布的一种常用方法。通过对双峰谱形的还原,对不同类型基函数的选择、基函数参数的设置和求解方法等影响解谱的因素进行了比较分析。根据大量算例的结果,使用优化后的基函数和求解方法对实际测量辐射谱进行了计算,并与透射光栅谱仪的测量结果进行了比较。结果显示,根据谱仪通道响应选择三次样条的节点,能够较好还原软X射线的能谱。     

HT-7电子加热实验的软X射线能谱诊断

介绍了HT-7装置上软X射线能谱诊断系统,用软X射线能谱对HT-7托卡马克上电子温度进行了测量。在离子伯恩斯坦波和低杂波协同实验中,观察到了对等离子体的较好的加热效果。     

Simple models for wentzel-druyvesteyn satellite energies in soft X-ray emission spectra of molecules

Simple models for the energy displacement between Wentzel-Druyvesteyn satellites and main lines in soft X-ray emission spectra of molecules are presented. The models include effective hole-hole interaction parameters and are evaluated numerically for H₂O.     

类锂氯离子和钾离子软X射线激光光谱理论计算

本文采用Hartree-Fock自洽场方法,从理论上计算了类锂氯离子和类锂钾离子可能实现软X射线激光的有关能级能量及跃迁谱线性质:跃迁波长、跃迁几率和振子强度。计算结果表明,类锂钾离子的部分跃迁非常有可能实现软X射线激光,并且其中有三条谱线的波长已进入水窗。     

The absorption of hydrogen by binary vanadium-chromium alloys

The thermodynamic parameters of the solution of hydrogen in binary vanadium-chromium alloys (to 20 at. % Cr) have been determined. The partial molar enthalpy at infinite dilution increases with increasing Cr content (values range from ?7615 cal/H in pure vanadium to ?5891 cal/H in V/19.96 at. % Cr). The partial molar entropy of solution is unaffected by the presence of Cr. It is suggested that this behavior indicates that Cr atoms do not block potentially available interstitial sites for occupation by hydrogen. The apparent H-H interaction is diminished by the presence of Cr. The stability of the dihydride is decreased by Cr additions, to the point that V/19.96 at. % Cr does not form a dihydride (?78°C, 68 atm). X-ray data indicate that the structural characteristics of the alloy hydrides are similar to those observed in vanadium/hydrogen.     

Vacancies in binary alloys

General expressions for the concentrations of divacancies and single vacancy-atom complexes in substitutional binary alloys is derived, using a model taking into account the interaction of neighbouring atoms as well as the interaction between vacancies and neighbouring atoms. The results of this paper are compared with those obtained with help of former theories, based on more restricted conditions.     

Phonon resistivity in concentrated aluminium alloys

The resistivity of aluminum based alloys containing V, Fe, Co, Ni and Cu has been measured between 4.2 and 100°K. The wide range of concentrations covered by our samples was obtained by the use of a rapid quenching technique, and the highest impurity resistivity is more than one order of magnitude higher than the interval previously explored.It is found that previous observations of a phonon resistivity varying as T³ and depending only on the impurity resistivity are still valid also in this range.     

Self consistent screening in concentrated alloys

In this paper, we discuss how to introduce self consistent values for the local energy levels and hopping integrals in the basic tight binding Hamiltonian for concentrated alloys. We then generalize the usual CPA approximation for this Hamiltonian to take into account the self consistent values.     

Cluster spin glass in concentrated alloys

Spin glass and structural states of Ni-Mn, Ni₃Mn-Ni₃V and Ni₃Mn-Ni₂Cr systems of alloys are investigated. The “freezing” temperature T _g of spin glass and Curie temperatures are obtained from the temperature dependence of the differential magnetic susceptibility χ_ac. Structural states of alloys are studied by the neutron diffraction technique. A cluster mechanism of spin glass formation is established.     

Electromigration in non-dilute binary alloys

This paper comments the recently published works on the electromigration in non-dilute binary alloys and gives a general analysis for calculating the effective valences $\text{Z}{}_{\mathrm{i}}{}^1$ of both components from experimental measurements. The proposed expressions for $\text{Z}{}_{\mathrm{i}}{}^1$ can be reduced to simple forms when Manning's expressions [5] for the phenomenological coefficients are used. These results allow us to calculate the effective valences of Silver and Gold in non-dilute Ag-Au alloys from Hofman and Guy's experimental data.     

Optical modes in binary alloys

The existence of a high-frequency, long-wavelength mode in a binary alloy is discussed on the basis of the fourth frequency moment of the correlation between concentration fluctuations.     

Anisotropic ordering in binary alloys

The problem of ordering in a binary alloy with anisotropic interaction between atoms is analyzed in the Kirkwood approximation. It is shown that the emerging oriented superstructure does not depend on the isotropic component of ordering energy. Transition to the ordered state destroys the short-range anisotropy. The constant of induced magnetic anisotropy is calculated for a ferromagnetic alloy, while its dependence on the alloy composition and the degree of far-range order as well as on the anneal temperature and the test temperature is established.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 109–112, March, 1976.     

软X射线掠射筒状反射镜镀镍磷合金的研究

在软X射线掠射光学系统筒状反射镜的加工过程中,根据对反射镜内表面镍磷合金镀层的质量要求,采用镍盐还原法对筒状微晶玻璃反射镜的内表面进行了活化,并对在含有30g/LNiSO4.6H2O、30g/LNaH2PO2.H2O、25g/LNa(CH3COO).4H2O、18g/LC6H8O7、10mg/L添加剂的镀液中沉积镍磷合金镀层的工艺方法进行了探索。对得到的镍磷合金镀层的结合力、抗腐蚀能力等进行了测试。结果表明,采用此法镀制的镍磷合金镀层结合力达到4B级,耐蚀性好,能够满足光学精密抛光的要求。