冷原子吸收法测定土壤中总汞

本文使用自制的汞原子化装置，与原子吸收仪联用，采用冷原子吸收法测定土壤中总汞，该法快速，简便，稳定性好，用于实际样品测试，结果令人满意。     

MEMS Torsion-Mirror Actuators for Optical Switching or Attenuating Applications

Novel MEMS torsion-mirror actuators with monolithically integrated fiber self-holding structures are fabricated,and investigated experimentally and theoretically. Their electromechanical and optical characteristics are acceptable for optical switching or attenuating applications.     

冷原子吸收光谱法测定饲料中痕量汞

本文使用汞原子发生装置与原子吸收仪联用，采用冷原子吸收光谱法测定饲料中的痕量汞，方法检出限为0.19μg/L；回收率为95％－103％；相对标准偏差为1.9%。该方法简便、准确度高、重现性好，适用于饲料中痕量汞的测定。     

微裂纹串级连接及临界破坏

对一铝合金材料层裂过程的实验研究发现，当损伤累积到一定程度时，受损材料的残余强度突然丧失，表现出临界破坏现象。层裂表面具有分形特征，其分形断面的形成归因于大量微裂纹的串级连接。据此提出了一重正化群弱面模型，并对损伤演化后期的临界破坏现象进行了初步的分析和探讨。     

Formulation of statistical evolution of microcracks in solids

The paper presents a principal formulation of statistical evolution of microcracks, occurring in solids, subjected to external loading. In particular, the concept of ideal microcracks is elaborated, in order to describe the fundamental features of damage resulting from nucleation and extension of microcracks. Relevant average damage functions are also discussed. The project partially supported by National Natural Science Foundation of China     

统计细观损伤力学和损伤演化诱致突变（Ⅱ）

材料的损伤和破坏是固体力学中一个十分复杂的基本问题，近年来在这方面的研究从不同的角度取得一系列新的进展。本文较系统地介绍了统计细观损伤力学和损伤演化诱致突变理论，这是把力学与统计物理学及非线性科学结合起来研究材料损伤和破坏问题的一种探索。     

An experimental study of spallation criterion in phenolic-resin based woven roving glass fibre reinforced composite material

An experimental study of spallation in phenolic-resin based woven roving glass fibre reinforced composite material under uniaxial strain condition is reported in this paper. Experiments were carried out with a 101 mm bore single-stage light gas gun. The stress waves induced by plate impact propagate along the normal to glass fibre mats. The experiments show that the threshold of incipient spallation in this material depends strongly on the duration of stress wave and that this incipient spallation appears essentially in one layer. The criterion of spallation in this material given in this paper is in good agreement with experimental results. Besides, the spallation in phenolic-resin based obliquely laminated woven roving glass fibre reinforced composite material is also discussed in this paper.     

固体的统计细观力学——-连接多个耦合的时空尺度

从固体力学所面临的新的挑战------多物理、多尺度耦合及其现状的描述开始, 以层裂 过程为例, 说明了这些多尺度非平衡问题的基本困难在于, 在固体中不同尺度上有不同的微 结构层次及不同的演化物理和速率. 接下来, 概述了一些针对这一困难的独特的思路及 其成果. 第3部分强调了一些统计平均方法的范式, 以及处理包含多个时间和空间尺度的问 题的新思路, 特别是非平衡损伤演化导致宏观失效的问题. 在第4部分, 简要评述了一些连 接多个空间和时间尺度的细观力学框架, 如位错理论, 物理细观力学, Weibull理论, 随机 理论等, 并且阐述了其中蕴含的跨尺度耦合的机理. 然后, 在第5部分, 回到了描述损 伤演化过程的框架, 也就是统计细观损伤力学以及它的跨尺度封闭近似. 基于这些跨尺度框 架, 在第6部分, 对控制跨尺度耦合的可能机理进行了评述和比较. 由于对失效时灾变 的洞察与跨尺度强耦合紧密相关, 一些非平衡和强相互作用的新概念在第7部分进行了讨 论. 最后, 以一个简短的总结和一些建议结束.     

Experimental and theoretical study on numerical density evolution of short fatigue cracks

Fatigue testing was performed using a kind of triangular shaped specimen to obtain the characteristics of numerical density evolution for short cracks at the primary stage of fatigue damage. The material concerned is a structural alloy steel. The experimental results show that the numerical density of short cracks reaches the maximum value when crack length is slightly less than the average grain diameter, indicating grain boundary is the main barrier for short crack extension. Based on the experimental observations and related theory, the expressions for growth velocity and nucleation rate of short cracks have been proposed. With the solution to phase space conservation equation, the theoretical results of numerical density evolution for short cracks were obtained, which were in agreement with our experimental measurements. The project supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences.