环境辐射仪器γ照射量率刻度的阴影屏蔽法

概述了阴影屏蔽法的操作步骤。对阴影屏蔽法所不能扣除的端墙面阴影部分A_0的γ反散射贡献进行了估算:当被刻度的仪器距端墙1.5m远时,端墙面阴影部分A_0的γ反散射贡献约为0.1—1%。对过阴影屏蔽与阴影屏蔽不足等若干影响因素分别进行了实验或讨论。     

银铜复合电触点复合强度检测方法的讨论

贵金属及其合金铆钉型复合电触点除了应考核其冷态复合强度之外，还必须增加在热态下复合强度的考核，只有这样才能满足用户在产际运行时对复合触点复合强度的要求。     

核素^147Pm在细胞内滞留的电镜放射自显影研究

木文用电镜放射自显影术研究了重核裂片~(147)Pm在体内亚细胞水平滞留动态。发现~(147)Pm的内污染沉积早期在血细胞和血管内皮细胞中,尤以在红细胞的沉积为多。~(147)Pm呈选择性滞留于肝细胞亚微结构中,可较多的掺入枯否细胞、肝细胞核和核仁内,在胞质中的糙面内质网、线粒体、微体和糖元中亦有滞留,且主要沉积于糙面内质网和线粒体,在高尔基复合体与糙面内质网所芽生的转移小泡融合处,亦有~(147)Pm滞留的放射自显影象。而在肾小体足细胞的线粒体和溶酶体中,有浓集的放射自显影径迹呈现。在肾近端小管曲部上皮细胞核中和胞质的线粒体和微体中,亦有较多的~(147)Pm滞留。 随着观察时间的延续,~(147)Pm在骨有机质亚微结构中呈现选择性、持续性的沉积增多。可浓集于破骨细胞和成骨细胞核中。此外在骨组织细胞间质中的胶原纤维部位,亦有较多的~(147)Pm沉积,难以排除。     

TiN/NbN纳米多层薄膜的交变应力场和超硬效应

为了研究纳米多层薄膜的超硬效应 ,采用反应溅射法制备从 1 4nm至 2 7nm不同调制周期的一系列TiN/NbN纳米多层膜。高分辨电子显微镜对薄膜的调制结构和界面生长方式的观察发现 ,TiN/NbN膜具有很好的调制结构 ,并呈现以面心立方晶体结构穿过调制界面外延生长的多晶超晶格结构特征。显微硬度测量表明 ,TiN/NbN纳米多层膜存在随调制周期变化的超硬效应。薄膜在调制周期为 8 3nm时达到HK39 0GPa的最高硬度。分析认为 ,两种不同晶格常数的晶体外延生长形成的交变应力场 ,对材料有强化作用 ,这是TiN/NbN纳米多层膜产生超硬效应的主要原因     

双瓣止回阀阀瓣强度分析及优化设计

通过对双瓣止回阀阀瓣的有限元分析,介绍了有限元分析法在阀门强度和刚度分析方面的应用。     

阴极电泳涂料进展

纵观阴极电泳涂装的发展史,在综述阳离子型树脂的合成方法和阴极电泳涂料的基本组成之后,指出今后阴极电泳涂料将向中厚膜、厚膜、高光泽、高充填性、高平整性、高边棱覆盖及低温固化等方向发展。     

PROMOTER FLOW ACTION OF SOLID-STATE LOW MELT POINT METAL ON THE POLYPROPYLENE

With the aid of a slip-disentanglement theo-ry,a reological equation has been deduced about the compos-ite system of solid-state low melting point metal and poly-mer. By measuring some rheological properties of the compos-ite system composed of low melt point metal and polypropy-lene (LMPM/PP),the results show that LMPM has a pro-moter flow action upon PP when using a small amount ofLMPM and , if some coupled agents are added,the promoterflow action will be remarkable. Moreover, while LMPM beingadded into the composite,the temperature sensitivity of systemwill go up. This indicates that the system’s viscosity will dropfurther if its temperature is increased.     

高压熔断器原理及分类

文章就高压熔断器原理及分类作了简要说明，特别对不同保护对象，对熔断器的不同要求作了介绍。     

Structure, Infrared Radiation Properties and Mssbauer Spectroscopic Investigations of Co_(0.6)Zn_(0.4)Ni_xFe_(2-x)O_4 Ceramics

Ferrite compound Co0.6Zn0.4NixFe2-xO4 was synthesized by solid state reaction. The structure and performance of Co0.6Zn0.4NixFe2-xO4 compounds were studied by Mssbauer spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared radiant tester. Mssbauer spectroscopy and XPS analysis show the valence states and distribution of cations in Co0.6Zn0.4NixFe2-xO4. Zn2+ has invariably shown preference for the tetrahedral sites, and Ni2+ has the preference for the octahedral sites. T...     

Bio‐oil from whole‐tree feedstock in resol‐type phenolic resins

Renewable chemicals are of growing importance in terms of opportunities for environmental concerns over fossil‐based chemicals. Lignocellulosic biomass can be converted into energy and chemicals via thermal and biological processes. Among all the transformation processes available, fast pyrolysis is the only one to produce a high yield of a liquid‐phase product called bio‐oil or pyrolysis oil. Bio‐oil is considered to be a promising substitute for phenol in phenol formaldehyde (PF) resin synthesis. In this work, bio‐based phenolic resins have been formulated, partially substituting phenol by bio‐oils from two Canadian whole‐tree species. The new resins are produced by replacing 25, 50, and 75% of phenol with bio‐oil for each species (three bioresins per species). The aim of this study is to synthesize renewable resins with competitive price and satisfactory quality. The results obtained have shown that substitution degree up to 50% provided reactivity and performance equal or superior to the pure PF resin. They also present a good storage stability, improved shear strength, and thermal stability comparable to the pure PF. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40014.