A Novel Electrostatic Guiding Scheme for Cold Polar Molecules in Weak-Field-Seeking States

We propose a novel electrostatic guiding scheme for cold polar molecules in weak-field-seeking states using a single charged wire half embanked in a ceramic substrate (i.e., a chip) and a homogeneous bias electric field, which is produced by a capacitor composed of two large parallel metal plates. We calculate the spatial distribution of the electrostatic fields generated by the combination of the charged wire and the plate capacitor and the corresponding trapping potentials for CO molecules, and analyse the relationships between the electric field and the parameters of the charged-wire layout. Our study shows that the proposed scheme with a single charged-wire can be used to guide cold polar molecules in the weak-field-seeking states, and has some potential applications in construction of various molecule-optical elements.     

自制简易教具提高课堂效率

实验在物理教学中起着重要的作用.由于配置实验仪器数量有限,并且配置仪器不可能十全十美,因此教师根据实际情况自制一些简易教具,既可以弥补配置仪器的不足,又可以提高教师的业务素质,同时还可以使一些复杂实验简单化,抽象实验形象化,演示实验大众化.     

导体表面的电荷分布

从对称性角度出发讨论了导体表面的电荷分布问题，并对“电荷密度分布函数”的理论作了评述。     

Electrostatic Nonlinear Structures in Dissipative Electron--Positron--Ion Quantum Plasmas

Low frequency （in comparison to ion plasma frequency） ion-acoustic shocks and solitons in superdense electronpositron-ion quantum plasmas are studied. The quantum hydrodynamic model is used incorporating quantum Bohm forces and Fermi-Dirac statistical corrections to derive the deformed Korteweg de Vries-Burgers （dKdVB） equation in weakly nonlinear limit. The travelling wave solution of dKdVB equation is presented and results are discussed in different limits. It is found that shock height increases with increase of quantum pressure, positron concentration and dissipation. Further, it is seen that the width of soliton decreases with increase of quantum pressure     

静电及其应用

 静电学是一门古老而又年轻的科学.自然界的一切运动,从一粒灰尘的飘荡沉浮,到震撼天地的电闪雷鸣,无不包含电的作用.动物中的电鳗、植物中的食虫草,更是把电作为获取食物、维持生命的手段.我们人类的身体也是由成万成亿个微型电池--细胞所组成.     

理解磨擦起电应注意的三个问题

物理课本一般在介绍摩擦起电时,总引入这样的话:用丝绸摩擦过的玻璃棒带正电,用毛皮摩擦过的橡胶棒带负电.学生学习过程中,容易对此产生片面的理解,因此教师应引导学生澄清三个概念.