Dissociative excitation cross sections of the lead atom in collisions between electrons and PbI2 molecules

Dissociative excitation of the lead atom in e-PbI₂ collisions has been studied experimentally. 27 excitation cross sections were measured for an energy of the exciting electrons equal to 100 eV. Nine optical excitation functions were recorded with variation of the electron energy in the range 0–100 eV. The most probable reaction channels for low electron energies are discussed, as well as the ratio of the dissociative excitation cross sections for the lead atom in e-PbI₂ and e-PbCl₂ collisions. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 701–706, November–December, 2006.     

自制金割效应物理摆的研究性实验

金割效应物理摆是将数学中的优选法与物理实验中的复摆结合起来并用计算机处理数据的自制教学仪器.把金割效应物理摆作为研究性实验进行开设,更有利于培养学生的开拓精神和创新能力.     

Ba（n，x）~（134）Cs，~（134）Ba（n，2n）~（133）Ba，

用中子活化法相对于５４Ｆｅ（ｎ，Ｐ）５４Ｍｎ反应，在１３．５０—１４．８０ＭｅＶ中子能区测量了Ｂａ（ｎ，ｘ）１３４Ｃｓ，１３４Ｂａ（ｎ，２ｎ）１３３Ｂａ，１４０Ｃｅ（ｎ，２ｎ）１３９Ｃｅ，１４２Ｃｅ（ｎ，２ｎ）１４１Ｃｅ和２３Ｎａ（ｎ，２ｎ）２２Ｎａ的反应截面．并将所测的结果和其他作者的结果进行了比较，中子能量是用９０Ｚｒ（ｎ，２ｎ）８９ｍ＋ｇＺｒ反应和９３Ｎｂ（ｎ，２ｎ）９２ｍＮｂ反应截面比法测定的。     

F／Cl比与Eu~（2＋）：BaFCl中F色心的浓度和光激励截面的关系

研究了Ｅｕ（２＋）：ＢａＦｘＣｌ２在紫外线辐照下的光激励发光。通过改变激励方式及激励光的扫描方向，给出了Ｅｕ（２＋）：ＢａＦｘＣｌ２－ｘ光激励发光过程中，两种Ｆ色心的浓度比值与光激励截面比值的测定方法。利用这种测定方法，进一步研究了两种Ｆ色心的浓度比值和光激励截面比值与Ｆ／ＣＩ比值的关系。     

An Alternative Approach to the Extraction of Structure Functions in Deep Inelastic e-p Scattering at 5 to 20 GeV

Two structure functions W1(x,Q2) and W2(x,Q2) are determined by using the cross sections measured in the deep inelastic electron-proton scattering experiments at Stanford Linac in the energy range of 5 to 20 GeV. In this paper an alternative mathematical approach have been used in such determination, resulting in a larger number of points in the graphs of the structure functions.     

核内核子－核子非弹散射截面（Ⅰ）

在与平均场、核内核子－核子弹性散射截面以及输运方程相统一的理论框架内推导了核内核子－核子非弹散射截面的解析表达式．其数值结果能很好地重现自由非弹截面的实验值，所计算的有效非弹截面与Ｄｉｒａｃ－Ｂｒｕｅｃｋｎｅｒ的计算结果相一致．     

Cr^4＋：YAG,Cr^4＋：Mg2SiO4近红外荧光辐射温度特性研究

测量了Ｃｒ＾４＋，ＹＡＧ、Ｃｒ＾４＋，Ｍｇ２ＳｉＯ４晶体在室温和液氮温度下的荧光光谱，吸收光谱和激发态寿命，讨论了温度变化时，两种晶体中Ｃｒ＾４＋近红外辐射积分强度变化与激光发态寿命变化的关系，得出结论：在７７Ｋ￣３００Ｋ范围内，Ｃｒ＾４＋的＾３Ｔ２能级荧光辐射截面本身受温度影响不大，Ｃｒ＾４＋辐射荧光的变化，主要是由无辐射弛豫速率随温度变化而引起的。     

Courants caractéristiques et analyse de SEREigen currents and RCS analysis

In this Note, we return to the theory of characteristic modes which was introduced 30 years ago for electromagnetic scattering problems. A simple mathematical framework is proposed and complete definitions are given. The potential interest of this theory in terms of Radar Cross Section (RCS) analysis is then discussed, especially in the low frequency case. Finally, a 3-D example is presented to illustrate the efficiency of this decomposition. To cite this article: Y. Morel et al., C. R. Mecanique 332 (2004).     

Probing proton halo of the exotic nucleus28S by elastic electron scattering

Elastic electron scattering on the exotic light nucleus²⁸S is investigated in the plane wave Born approximation. The variation of the squared form factors of²⁸S with momentum transfer is compared with that of³²S. It is found that the behavior of the form factors near the second minimum (with a moderate momentum transfer) is sensitive to the alteration of the charge density distribution of halo protons in²⁸S. This indicates that elastic electron scattering can be a good probe of the structure of proton-halo nuclei.     

常曲率空间中单形的中面公式及其应用

本文给出了n维常曲率空间中单形的中面面积公式，利用它我们还得到了一类几何不等式．