层裂微裂纹的形态及层裂程度的表征参量

文中运用超声C扫描检测系统对层裂试件的微损伤形态进行检测，确是出在一维应变加载条件下的微裂纹形态呈钱币型；另一方面，根据钱币型微纹形态，通过对层裂损伤演经过程的分析，提出了一个描述层裂程度的无量纲参量，与层裂实验数据的对比说明了这个参量能够很好地描述层裂损伤程度

Embryo-damage induced nucleation of microcracks in an aluminum-alloy under impact loading

The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminium matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of embryo-damage induced nucleation by fracture of brittle particles in the aluminium alloy under impact loading was proposed

Embryo-damage induced nucleation of microcracks in an aluminum-alloy under impact loading

The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminium matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of embryo-damage induced nucleation by fracture of brittle particles in the aluminium alloy under impact loading was proposed

Statistical formulation and experimental determination of growth rate of micrometre cracks under impact loading

A new statistical formulation and a relevant experimental approach to determine the growth rate of microcracks were proposed. The method consists of experimental measurements and a statistical analysis' on the basis of the conservation law of number density of microcracks in phase space. As a practical example of the method, the growth rate of microcracks appearing in an aluminium alloy subjected to planar impact loading was determined to be ca. 10 mu m/mu s under a tensile stress of 1470 MPa and load duration between 0.26 mu s and 0.80 mu s

超细ZSM-11分子筛低温合成及表征

以硅溶胶和白碳黑为硅源，在TBAOH－Na2O-SiO2-H2O体系中，在低温下合成出100－200nm的超细ZSM－11分子筛，研究了晶化时间的影响，发现低温下时间对结晶度与晶粒大小的影响较小，采用SEM，TEM，XRD，IR，^29Si MAS NMR,^13C CP/MAS NMR,XRF,N2物理吸附和NH3－TPD对其进行了表征，发现晶粒大小影响其物化性能

超细ZSM-11分子筛低温合成及表征

以硅溶胶和白碳黑为硅源，在TBAOH－Na2O-SiO2-H2O体系中，在低温下合成出100－200nm的超细ZSM－11分子筛，研究了晶化时间的影响，发现低温下时间对结晶度与晶粒大小的影响较小，采用SEM，TEM，XRD，IR，^29Si MAS NMR,^13C CP/MAS NMR,XRF,N2物理吸附和NH3－TPD对其进行了表征，发现晶粒大小影响其物化性能