e-A深度非弹性散射中胶子辐射振幅的新计算方法

在e-A深度非弹性散射过程中, 喷注穿过冷核介质时, 多重散射诱导胶子辐射会导致对碎裂函数的修正及喷注的能量损失.前期研究中关于计算e-A深度非弹性散射中胶子辐射振幅的两种方法: 螺旋振幅近似和微扰QCD严格计算都异常繁杂. 本文发展了一种新的方法, 可以方便计算出多重散射导致胶子辐射的振幅, 得到的碎裂函数的修正以及能量损失与严格计算的结果一致.     

Modeling of radiative heat transfer in an axisymmetric cylindrical enclosure with participating medium

Radiative heat transfer in an axisymmetric enclosure with absorbing, emitting, and scattering medium is studied here by using the different methods such as MDOM, FVM, and MFVM with emphasis on the treatment of angular derivative term, which appears in curvilinear coordinates due to angular redistribution. After final discretization equation for MFVM is introduced by using the step scheme and directional weights, the present approach is validated by applying it to three different benchmarking problems with absorbing, emitting, and scattering medium. All of the results presented here support its accuracy as well as moderate efficiency. Finally, the present approaches are applied to a truncated cone-shaped enclosure as a body-fitted geometry case.     

Determination of electron temperature based on a semicoronal model in Hall accelerator plasma flows

We present the results of a spectroscopic study of a nonequilibrium plasma in a Hall accelerator, in particular for such an important parameter as the electron temperature. For the studied conditions, we used the semicoronal equilibrium model, which relates the intensity ratios for two successive ionization steps for the same element. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 93–96, January–February, 2007.     

Quantification of trace elements in human serum fractions by liquid chromatography and inductively coupled plasma mass spectrometry

On‐line coupling of LC and ICP‐MS has been used for fractionation and detection of species of Cu, Fe, I, Se and Zn in human serum. It has been shown that anion exchange chromatography provided better separation capability (both intra‐ and inter‐element) than size‐exclusion chromatography. The mobile phases for ion exchange chromatography consisted of Tris–HNO₃ buffer and ammonium salt (nitrate, acetate or formate). Formate was found to be the best mobile phase counter ion, enabling good chromatographic separation, and is acceptable for mass spectrometry too. The quantitative evaluation of element concentrations adhering to individual fractions was performed by the peak area normalization method. The repeatability of results ranged from 3 to 15% (depending on the element concentration level) and represented the main part of the result uncertainty. The accuracy of Cu and Zn fraction determinations was confirmed by comparison with the isotope dilution technique. Copyright © 2006 John Wiley & Sons, Ltd.     

Cylindrical KP-Burgers Equation for Two-Temperature Ions in Dusty Plasma with Dissipative Effects and Transverse Perturbations

In this paper, the cylindrical KP-Burgers equation with variable coefficient for two-temperature ions in unmagnified dusty plasma with dissipative effects and transverse perturbations in cylindrical geometry is derived by using the standard reductive perturbation technique. With the help of variable-coefficient generalized projected Ricatti equation expansion method, the cylindrical KP-Burgers equation is solved and shock wave solution is obtained. The effects of some important parameters to the shock wave solution are illustrated from the wave evolution figures. The effects caused by dissipation and transverse perturbations are also discussed.     

Vibrational Dynamics Studies by Nuclear Resonant Inelastic X-Ray Scattering

Nuclear resonant inelastic X-ray scattering of synchrotron radiation is being applied to ever widening areas ranging from geophysics to biophysics and materials science. Since its first demonstration in 1995 using the ⁵⁷Fe resonance, the technique has now been applied to materials containing ⁸³Kr, ¹⁵¹Eu, ¹¹⁹Sn, and ¹⁶¹Dy isotopes. The energy resolution has been reduced to under a millielectronvolt. This, in turn, has enabled new types of measurements like Debye velocity of sound, as well as the study of origins of non-Debye behavior in presence of other low-energy excitations. The effect of atomic disorder on phonon density of states has been studied in detail. The flux increase due to the improved X-ray sources, crystal monochromators, and time-resolved detectors has been exploited for reducing sample sizes to nano-gram levels, or using samples with dilute resonant nuclei like myoglobin, or even monolayers. Incorporation of micro-focusing optics to the existing experimental setup enables experiments under high pressure using diamond-anvil cells. In this article, we will review these developments. This revised version was published online in August 2006 with corrections to the Cover Date.     

Investigation of laminar plasma remelting/cladding processing

Investigation of remelting and cladding processing with laminar plasma jets on several metals has been conducted looking for possible development of a new surface modification technique. The remelting tests illustrated that the new method could evidently improve the material microstructure and properties of cast iron. The cladding was done with Al₂O₃ ceramic powder on stainless steel. The energy dispersive spectra (EDS) analysis was used to determine the distribution of the major cladding element in the plasma-processed layers, for which the microstructure observations and hardness measurements were also performed.     

吸积盘的X射线辐射对周围星际物质的离化研究

利用辐射流体力学程序对三倍频纳秒激光与靶物质相互作用进行了模拟研究，得到了可以产生黑体辐射谱分布的激光等离子体X射线辐射靶的最佳厚度；数值模拟研究了黑体谱分布的X射线辐射场对等离子体系统平均离化度分布的影响，它有助于深入理解天体物理中吸积盘对它周围星际物质的离化影响. 关键词： 辐射流体力学 激光等离子体 X射线辐射 吸积盘 离化     

Quantum Tunneling of Massive Particles from a Garfinkle-Horowitz-Strominger Dilatonic Black Hole

Hawking radiation is viewed as a process of quantum tunneling. The massive particles‘ tunneling from Garfinkle-Horowitz-Strominger black hole is investigated. Using Jingyi Zhang‘s de Broglie wave method, we get the unthermal spectrum, and the result is consistent with the underlying unitary theory.     

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