I-fuzzy拓扑空间的次分离公理

在I-fuzzy拓扑空间中引入次T1和次T2分离公理,新的分离公理具有预期好的性质,如:具有遗传性和可乘性,在次T2空间中分子网收敛唯一等。初步讨论次分离公理与其它分离公理的关系。     

钼晶体中的位错线蚀象的研究

实验结果表明,应用甲醇、硫酸、盐酸的混合液为电解浸蚀剂,可以在钼晶体的{100},{111}及{110}面上显示位错蚀斑,而在{111}面及{110}面上同时可以显示出排列成平行线或六方网络的蚀线,这些蚀线被证明为位错线的蚀象。根据观测结果,总结出解释位错线蚀象的经验规律:观测到的蚀象相当于一定深度内位错线在观察面的投影;蚀象的宽度决定于位错线段到原始表面的距离,距离愈远,宽度愈细,类似于一种夸张的光学透视效应,因而根据蚀象就可以直接推出位错线在空间的位置,采用多次浸蚀的方法,对于一些位错空间排列组态的实     

铌酸钡钠晶体中与位错相关的铁电畴

本文报道了对原生态铌酸钡钠晶体中与位错相关的铁电畴的系统观测结果。除沿c轴直线延伸的位错线不存在相关铁电畴外,具有各种形态特征、不同柏格斯矢量、不同走向的所有位错线都存在与之相关的铁电畴。在由交锁带纹状铁电畴构成的“中性”区域内,位错相关铁电畴由分居位错线的c方向两侧、极性相反且极化方向背向位错线的两个铁电畴管道所构成。铁电畴管道的形状与位错线的走向有关,但不因位错线的柏格斯矢量的不同而有明显差异。在较大的单畴区内,只出现与基底铁电畴极性相反的一翼。位错线攀移路径的两侧也存在极性的类似变化。文中还对产生位错相关铁电畴的可能原因进行了分析。     

冯端──祖国土地上成长起来的学部委员

冯端,祖籍浙江绍兴,1923年4月27日生于江苏苏州.祖父年轻时赴江西谋生,中年早逝.父亲冯祖培,清末科举考试中曾以陪考而中试,但不久因废科举而未获功名,中年投身仕途.他擅书法;工诗词,依然一介书生.母亲严素卿,也是寄寓安徽的绍兴人.他们生有三子一女.冯端长兄冯焕,1947年赴美国功读电机工程,获博士学位后定居美国,为通用电器公司研究发展中心高级工程师,现已退休,为东南大学名誉教授;姐姐冯慧,为中国科学院动物研究所研究员;二哥冯康,为中国科学院学部委员,任中国科学院计算中心主任;冯端排行最小. 冯端的童年是在苏州古城一条陋巷中度过的.…     

利用电子束浮区区熔法制备钼单晶体

本文简单介绍自制的1.5千瓦电子束浮区区熔装置及其工作情况。应用这种装置我们制备了直径4毫米、长2—5厘米的钼单晶体,并掌握了制备定向单晶体的实验技术。制备的钼单晶体没有择优取向;显微镜观察发现晶体表面有大量的台阶(高度在2.3×10^-5—6.3×10^-4厘米),初步推断为蒸发台阶。 关键词：     

用浸蚀法显示钼单晶中的位错线与网络

关键词：     

天然绿柱石晶体中生长区界面的X射线形貌和光学双折射形貌研究

用X射线形貌术及光学双折射形貌术对天然绿柱石晶体中的生长区界面进行了研究。观测发现,同类生长区的界面在两种形貌中通常不出现可见的衬度;异类生长区界面中,t-s界面在X射线形貌中呈现动力学干涉条纹衬度,表明它们具有平移型界面的特征,根据消光规律知其相应的位移矢量很可能与界面垂直;在双折射形貌中,异类生长区界面衬度的出现与界面两侧存在不同的长程应变场有关。实践表明,两种形貌术互相补充,互相参证,在生长区界面的研究中是十分有效的。     

DISLOCATION DISSOCIATION ON CLIMB PLANE IN TEXTURED YBa2Cu3O7-δ SUPERCONDUCTOR

Using high resolution electron microscopy, the structure of [100] tilt boundary with misorientation of 1.2° in YBa₂Cu₃O_7-δ has been determined. The boundary is shown to consist of an array of partial dis-locations, These partials result from the dissociation of a perfect dislocation with a Burgers vector [0, 0, c] on its climb plane according to the reaction, b→b₁+b₂+b₁+b₂+b₁+b₂. Here b=[00c], b₁=[O,b/2, c/6} (or [a/2, 0, c/6] ). b₂=[0, -b/2. c/6] (or[ -a/2, 0, c/6] ). The spacing between the perfect dislocations satisfies the Read-Shockley formula. There exist no amorphous phases in the boundary region.     

DISLOCATION DISSOCIATION ON CLIMB PLANE IN TEXTURED YBa2Cu3O7-δ SUPERCONDUCTOR

Using high resolution electron microscopy, the structure of [100] tilt boundary with misorientation of 1.2° in YBa₂Cu₃O_7-δ has been determined. The boundary is shown to consist of an array of partial dis-locations, These partials result from the dissociation of a perfect dislocation with a Burgers vector [0, 0, c] on its climb plane according to the reaction, b→b₁+b₂+b₁+b₂+b₁+b₂. Here b=[00c], b₁=[O,b/2, c/6} (or [a/2, 0, c/6] ). b₂=[0, -b/2. c/6] (or[ -a/2, 0, c/6] ). The spacing between the perfect dislocations satisfies the Read-Shockley formula. There exist no amorphous phases in the boundary region.     

ORDER ALLOY IN GexSi1-x/Si(100) STRAINED-LAYER SUPERLATFICES

The Ge_xSi_1-x/Si(100) strained-layer superlattices have been investigated by means of the transmission electron microscopy of the cross-sectional specimen (XTEM) and the high resolution electron microscopy (HREM), The order alloy with a period of modulation twice as large as the lattice constant along <100> zone axis has been found in the alloy layers of the superlattices with x≈0.4-0.5. This order struc-ture makes the superlattices inhomogeneously strained. The result of the compuler simulation shows that the order alloy exhibits an altemating stack of 2 monolayers of Ge atoms and 2 monolayers of Si atoms along the <100> zone axis. Thc calculated elastic strain energy of the disorder alloy reported in the litera-ture is very close to that of the order alloy along <100> zone axis. Thus, during the MBE growth of the alloy layers, both the disorder and order alloys can be formed along <100> zone axis.