The preparation and magnetic properties of Fe-Ag granular solid using a sol-gel method

The Fe-Ag granular metal solid samples with 10% and 30% weight iron have been successfully fabricated using a sol-gel method, which are characterized by X-ray diffraction and transmission electron micrography. The average diameters of iron particles are from about a few nanometres to a few tens of nanometres controlled by the reducing temperature. The evolution of magnetic properties and microstructure during heat treating are described in detail and explained by using the superparamagnetism, single domain and multi domain theories. The magnetic anisotropy of the Fe-Ag granular solid is studied by using the law of approach to saturation. It is found that the magnetic anisotropy constant is in the order of 10⁵ J m^–3 which is higher than the value of the bulk iron and increases with the increase of reducing temperature.     

沟槽控制爆破研究技术

文章通过对洋浦电厂海水冷却箱涵沟槽预裂（深孔）爆破技术的研究，提出了复杂地质条件下合理的控制爆破参数及微差起爆方式。针对砂层地段难以钻、爆的特点。笔者进行了有益的探讨。     

显影液QA,QC的科学方法

本文为自动洗片机用高温快速显影液的科学管理与质量保证提供了简便、科学的检测方法,力医(?)影像质量的提高提供了可靠的保证。具有科学性、实用性、普及性。     

沉积方式与基体材料对TiN薄膜内应力的影响

本文研究了TiN薄膜在化学气相沉积、物理气相沉积(包括热灯丝离子镀和多弧离子镀)以及等离子增强化学气相沉积等不同生成条件下的内应力变化。并通过改变钢及硬质合金基体的化学成份和表面状态。考察了基体材料对薄膜应力的影响。在此基础上,对薄膜内应力的形成机制进行了分析讨论。     

变速箱结构设计专家系统技术的研究

结构设计是机械产品设计过程中的重要环节，解决结构设计的智能化不但可以缩短产品的设计周期，而且还可以降低成本，提高设计质量。专家系统是解决智能化设计的技术之一。本文讨论有关结构专家系统的几个关键技术，主要包括系统的控制策略，面积对象的知识表达方式及结构设计的并行设计     

地面立体摄影测量在露天矿山的应用

本文针对露天矿验收测量的特点，论述了露天矿验收地面立体摄影测量方法及其内业处理系统，并将地面立体摄影测量结果与ＥＤＭ解析法测量结果进行了比较。     

Silicon carbide-toughened zirconia ceramics

Tetragonal zirconia polycrystalline (TZP) ceramics containing SiC reinforcement in the form of fine particles (nano-scale), particles (micro-scale), whiskers and platelets were synthesized by hot-pressing. The effects of morphology and grain size of SiC reinforcement on the strength and fracture toughness at room temperature were investigated. The addition of SiC (in whatever form) caused decreases in strength and toughness at room temperature with the exception of whisker-reinforced materials. Toughness fell off with increasing temperature, but nevertheless retained about one-half of the room-temperature value for that particular SiC reinforcement. However, the whisker- and particle-reinforced materials had higher K _lc values at high temperature than fine particle- or platelet-reinforced materials, with values in excess of 7 MPa m^1/2 at 1000 °C. The microstructure was examined for SiC whisker-reinforced/TZP materials by TEM and HREM, to examine the nature of the whisker/zirconia interface.     

Randomized trial of breast self-examination in Shanghai: methodology and preliminary results

BACKGROUND: The efficacy of breast self-examination in helping to reduce mortality from breast cancer has not been rigorously demonstrated. PURPOSE: To assess efficacy, a large, randomized trial was initiated in Shanghai, China. METHODS: From October 1989 to October 1991, 267040 current and retired female employees associated with 520 factories in the Shanghai Textile Industry Bureau were randomly assigned on the basis of factory to either a self-examination instruction group (133375 women) or a control group (133665 women). The women were born within the period from 1925 through 1958. Women in the instruction group were given intensive training in breast self-examination, including the use of silicone breast models and personalized instruction, plus two subsequent reinforcement sessions and multiple reminders to practice the technique. Women in the control group were asked to attend training sessions on the prevention of low back pain. All women have been followed for the development of breast diseases and for death from breast cancer. RESULTS: A high level of participation during the first 4-5 years of the trial was documented among women in the instruction group. Randomly sampled women in this group demonstrated greater proficiency in detecting lumps in breast models than did randomly sampled women in the control group. Approximately equal numbers of breast cancers were detected in the two groups (331 in the instruction group and 322 in the control group) through 1994, which is the last year for which case-finding efforts have been completed. The breast cancers detected in the instruction group were not diagnosed at an appreciably earlier stage or smaller size than those in the control group. More benign breast lesions were detected in the instruction group than in the control group (1457 versus 623, respectively), suggesting a higher index of suspicion for women who received training. Cumulative breast cancer mortality rates through 5 years from entry into the study were nearly equivalent for the two groups. CONCLUSIONS: Breast self-examination has not led to a reduction in mortality from breast cancer in this study cohort in the first several years since the trial began. A shift toward the diagnosis of disease at a less advanced stage in women given instruction has also not been demonstrated. Longer follow-up of participants in this trial is required before final assessment can be made of the efficacy of breast self-examination. IMPLICATIONS: At this time, there is insufficient evidence to recommend for or against the teaching of breast self-examination.