单晶金刚石刀具钎焊过程研究

对单晶金刚石刀具的钎焊过程进行了研究。指出合理选择单晶金刚石刀具的钎焊方法,严格执行钎焊工艺内容,控制好钎焊过程,可以有效预防或避免钎焊接头处缺陷的产生,有利于获得优质的钎焊接头,延长金刚石刀具的使用寿命。     

液体分配器与分液管的钎焊连接

制冷系统用的液体分配器与分液管接头钎焊方法的选择、钎焊时易出现的问题、正确的钎焊工艺和钎焊注意事项。     

钎焊金刚石工具的研究现状与展望

从钎焊工艺、钎焊料、工具产品和生产自动化4个方面介绍了当前国内外钎焊金刚石工具的研究成果，并在此基础上对钎焊金刚石工具下一步的研究重点进行了展望。详细论述了钎焊温度、保温时间、钎料合金成分对钎焊金刚石的影响。适宜的钎焊温度和保温时间可以保证金刚石/钎料界面发生充分反应，界面结合强度增强，获得较好的钎焊接头质量。添加适量的元素或化合物改进钎料合金成分，可以调控钎料的性能，降低金刚石石墨化和热损伤程度。概括总结了常规钎焊金刚石工具、磨粒有序排布钎焊金刚石工具及细粒度钎焊金刚石工具的发展现状，钎焊金刚石工具具有电镀和烧结金刚石工具无可比拟的优点；金刚石有序排布会提高工具的加工效率和使用寿命，提高磨削表面质量；对细粒度钎焊金刚石工具亟待解决的磨粒等高性和分布均匀性问题的研究进行了概述。     

激光钎焊质量影响因素分析综述

为了提升激光钎焊的连接质量,从激光参数、送丝过程、钎料类型与尺寸等方面分析了影响激光钎焊的各种因素,综述了激光钎焊质量影响因素的研究成果。研究表明,影响激光钎焊质量的因素是综合性的,应通过正交方法做实验,依据统计数据作出分析,从而得到激光钎焊的最佳参数。     

氮基可控气氛连续钎焊炉成套设备的研制

研制的氮基可控气氛连续钎焊炉 ,成功地解决了钢质零件的铜钎焊问题。是具有发展前途的新型钎焊设备。     

4004/3003/4004铝合金复合钎焊板包覆率研究

三层铝合金复合钎焊板是制造钎焊式热交换器的重要材料,其中4004/3003/4004是一种使用最为广泛的铝合金复合钎焊板。对4004/3003/4004铝合金复合钎焊板进行热轧复合,分析其包覆层宽度方向分布情况和上下包覆层厚度差异性,并研究不同初始包覆率下轧制后包覆率的变化规律,对实际生产中钎焊板包覆层厚度控制起到重要的指导作用。     

感应钎焊工艺对黄铜接头组织的影响

研究了感应钎焊时 ,不同钎焊参数对零件内外表面温度的影响 ,分析了钎焊工艺参数对母材组织和接头质量的影响。缓慢升温可使工件内外表面温度达到平衡 ,钎焊温度在 780℃以下 ,保温时间小于 2 0s的工艺参数可获得优良钎缝和不损伤母材组织。     

烧结钎焊粉末冶金零件研究

烧结钎焊是一种已确立的粉末冶金零件连接工艺,经常用于生产汽车零部件。成功的钎焊连接主要取决于钎焊合金、连接表面与烧结气氛间的相互作用。将广泛使用的钎焊合金,Ancorbraze 72(AB 72),设计成与焊接的母体材料形成合金和能局部密封钢粉末冶金零件的表面孔隙,从而可防止因熔渗造成钎料材料的大量损失。本文将检验在不同生产工艺条件下钎焊的性状,和研究与表征焊剂与铁使钎焊合金的改性对熔化与凝固性状的影响。     

不锈钢/碳钢拉拔钎焊复合管的实验研究

采用拉拔-钎焊的方式制备不锈钢/碳钢复合管,应用金相显微镜观察钎焊后复合界面的微观形貌,实验测试了钎焊温度和保温时间对复合强度的影响。研究发现,钎焊后金属间形成致密的冶金结合,随钎焊温度增加,金属间的剪切强度提高,当温度大于1150℃时,剪切强度从295MPa缓慢增加,随钎焊保温时间剪切强度呈先增大后降低规律。保温3h时剪切强度最大为301MPa。     

热轧4343/3003/7072铝合金钎焊板的组织与性能

采用热轧复合工艺生产4343/3003/7072铝合金钎焊板,利用光学显微镜、电子拉伸试验机和扫描电镜,研究了铝合金钎焊板的包覆率、显微组织和力学性能。结果表明,铝合金钎焊板的包覆层合金厚度均匀、复合界面平整,铝合金钎焊板中4343和7072铝合金包覆层的包覆率分别为9.0%和8.1%,铝合金钎焊板的抗拉强度、屈服强度和伸长率分别为118.62 MPa、56.21 MPa和32.48%。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.