单脉冲加载的Hopkinson扭杆装置

分析了反复加载现象及其对变形微结构的影响，介绍了对现有标准Ｈｏｐｋｉｎｓｏｎ扭杆的改进。改进后的新型Ｈｏｐｋｉｎｓｏｎ扭杆是具有特殊设计的加载头和传动器的四杆系统，它完全消除了应力波的反复加载效应，实现了过程的单脉冲加载。改进前后的实验波形和变形局部化微结构形态的比较证实了改进的有效性。     

Study of the substructure in nanometer copper thin films treated by laser shock processing

We study nanometer copper thin films prepared by magnetron sputtering and treated with laser shock processing (LSP). We observe the formation of firstborn twin crystals and some complete twin crystals in the copper thin films. After LSP, scanning electron microscope (SEM) images show obvious plastic deformation of the copper grain on the film surface, dramatically increased grain size, and the appearance of a large number of twin crystals. Moreover, the width of the crystals is a few dozen nanometers, and the cross angle is more than or close to 90°.Many vacancy defects appear during the sliding of atomic plane, which leads to a faulty structure; however, no obvious dislocation is observed. These substructures play a significant role in improving the mechanical performance of nanometer copper thin films.     

Visibility in magnetostrictive fiber-optic interferometric sensors and its dependence on the input SOP

The visibility in magnetostrictive fiber-optic interferometric sensors using a Gaussian laser beam is analyzed. It is shown that the conventional Gaussian laser beam has little influence on the visibility. The visibility depends strongly on the input state of polarization (SOP). We implement a cylindrical transducer and build a measurement setup with a polarization controller. The visibility dependent on the SOP of input light is measured. The estimated values are similar to the experiment results, which verifies the analysis.     

必须坚持辩证唯物论的认识论——谈如何看待热力学第二定律的几种说法之间的关系

读了《化学通报》1975年第1期发表的陈鹰同学的信后很受启发,它反映了经过无产阶级文化大革命和批林批孔运动的锻炼,我国青年一代的革命精神和教育战线的大好形势。关于热力学第二定律几种说法之间的关系,下面谈谈我们的一些看法。《热力学第二定律从物理说法导出数学说法》(《化学通报》1974年第5期,以下简称“说法”)把热力学第二定律的几种不同说法割裂开来,认为它们“彼此独