Al/Al2O3P金属基复合材料的静动态压缩性能及损伤分析

用气压浸渗工艺制备了体积分数40％～50％Al2O3颗粒增强纯铝基复合材料，使用了4种不同尺寸的Al2O3颗粒，其平均粒径分别为5μm、10μm、30μm和60μm．测定了这些复合材料的静、动态压缩性能，并通过材料压缩前后密度变化的测量定量表征了材料的累计损伤，结果表明，与基体材料相似，这些复合材料表现出明显的应变率敏感性；当增强颗粒平均粒径小于60μm时，材料的累计损伤基本与应变率无关，而主要取决于材料的应变．材料中颗粒的破裂主要是由颗粒间的相互作用引起的．较小尺寸颗粒增强的复合材料具有较高的流动应力和较小的累计损伤，并随着颗粒体积分数的增加，材料的流动应力和损伤率都相应增加．     

Structural Evolution of Nanostructured γ—Ni—28Fe Alloy Investigated by Using the Internal Friction Technique

The structural evolution of nanostructured γ-Ni-28Fe alloy(n-Ni-Fe)(grain size d-30nm),synthesized by the mechno-chemical method,was investigated by using the internal friction technique combined with differential scanning calorimetry(DSC) in the temperature range from 300K to 670K.An internal friction peak with typical characteristics of the first-order phase transition was observed in the vicinity of 620K,which corresponds to a broad exothermic process revealed by using DSC.Theses results can be explained as the structural changes from the disordering to the ordering transition in the n-Ni-Fe sample.     

Crystal Structure of Adduct 2-Phenyl-imidazo [ 4,5-f ] 1,10-phenanthroline Methanol

The structure of the title adduct comprises a phenanthroline derivative 2-phenyl-imidazo[4,5-f]1,10-phenanthroline and a methanol.The composition of the crystalline adduct was characterized as C19H12N4.CH3OH.It belongs to orthorhombic system,space group Pna21 with a=1.3693(4)nm,b=2.2988(7)nm,c=0.51338(15)nm,V=1.6160(8)nm^3.Z=4,and final R1=0.0423.wR2=0.1012 .Crystal structure shows that all the 19 carbon atoms and 4 nitrogen atoms are coplanar.The bond length data indicated that a very extensive conjugation system was formed.This conjugation makes the compound being a potentially excellent energy transformer used for luminescent materials.     

Emittance Measurements for Beams Extracted from LECR3 Ion Source

High quality ion beams are required by IMP cyclotron and atomic physics research, so it is important to research and measure beam emitt ance of ECR ion source. Intense beams extracted from ECR ion source usually have low energy, so it is suitable to use Electric-Sweep Scanner to measure the emittance. This kind of measurement is popularly used at ECR ion source, and it has some prominent merits such as high accuracy, very short time of data processing and easy expressing of the emittance pattern. So we designed and built this emittance scanner to measure emittance of the ion beams produced by LECR3 ion source. The structure of the ESS is shown in Fig.l, and the photo of the ESS is shown in Fig.2.     

Theoretical Studies on the Si（001）-SiO2 Interface Structure

1 INTRODUCTION Silicon and its alloy have been widely applied in such fields as electronic industry, high-temperature structural ceramics, etc. In addition, the researches on silicon and its relevant materials greatly promote the rapid development of modern optics and infor- mation technology. Therefore, more and more at- tention is focused on the structure of silicon, oxide of silicon and the interfaces between silicon and metal or nonmetal. As an ideal passive film on the Si surface, S…     

sl玻色子体系在U(2l+1)O(2l+2)过渡区的严格解

利用无穷维李代数方法得到了相互作用sl玻色子体系在U( 2l+ 1 ) O( 2l+ 2 )过渡区的能谱和波函数的严格解 .给出了该系统Bethe假定方程的数值解法 .     

Single＆Two—photon Excited Fluorescence of Two New Compounds with 2—Benzothiazoly as Electron Acceptor

Two new D-x-A type compounds,where electron-donor D is tertiary amino group,electron-acceptor A is 2-benzothiazolyl and x is two conjugated styryl units,have been synthesized.They are named as trans,trans-2-{4-[4-(N,N-diethylamino)styryl]styryl}-1,3-benzothiazole and trans,trans-2-{4-[4-(N,N-diphenylamino)styryl]styryl}-1,3-benzothiazole.Both compounds show strong two-photon excited fluorescence in yellow-orange region when excited by a femtosecond laser at 800nm.     

Fluorescence Microscopy of Nanoscale Silver Oxide Thin Films

The experimental conditions for photoactivated intermittent fluorescence from nanoscale silver oxide were studied with fluorescence microscopy.Strong fluorescence was observed from the Ag2O particles with size of 10-20nm excited with both blue and green light .We observed the saturation of Photoexcitation with blue light and explained the experimental results using the model of agglomeration of silver atoms to form small clusters and the fluorescence of Ag2 and Ag3 clusters.