ЗИ868合金成分对组织和性能的影响

通过研究碳、钼、铝等元素含量的变化对ЗИ868(GH3044)合金组织和性能的影响得出以下结论：在该合金技术标准规定的成分范围内，当碳含量控制在0．03％～0．06％时，合金的短时及长时力学性能均较好；钼、铝对合金性能的影响不如碳显著。钼的含量取下限可使合金具有较好的室温和高温塑性，铝含量控制在0．30％～0．50％时，合金具有较好的力学性能。此外，为了改善合金棒材的综合力学性能，固溶热处理应取上限温度(1150～1200℃)。     

GH648合金高温抗氧化性能的研究

GH648是一种时效硬化型镍基高温合金,主要用作航空发动机的启动机900℃以下的抗氧化承力件.在高温下,该合金不仅要有较高的强度,而且还要有较好的抗氧化性能.为此,本文探讨了GH648合金高温氧化机理并简单分析了C元素对合金抗氧化性能的影响.结果表明,GH648合金在空气中氧化时,其氧化膜主要为Cr2O3,该合金的氧化是以Cr在Cr2O3中的扩散为控制因素的;合金在低于900℃的空气中氧化时属于完全抗氧化级.随C含量的升高,合金的抗氧化性能降低.     

时效处理对GH648合金析出相和力学性能的影响

通过分析GH648合金时效处理后的相组成,研究不同时效处理温度对GH648合金组织和力学性能的影响,探讨了γ',及α-Cr相对合金性能的影响.结果表明,随着时效温度的提高,α-Cr相的析出量增加,γ'相的析出量减少,大多数α-Cr相呈针状分布在晶内,而且合金的室温拉伸塑性和冲击韧性随α-Cr相析出量的增加明显降低.     

碳,镍,钼对铸造Fe—Cr—Ni合金高温抗拉强度的影响

当碳含量为０．１０％￣０．７０％时，随碳量增加，Ｆｅ－Ｃｒ－Ｎｉ合金１２５０℃高温抗拉强度显著提高，在碳量大约为０．４０％，时达到峰值，而后急剧下降，同样，镍为１０％和钼为０．３％，合金１２５０℃高温强度最大。     

三种热处理制度对GH648合金组织和性能的影响

 研究了A、B、C三种热处理制度对GH648合金组织和性能的影响。结果表明，与标准热处理制度A相比，经B、C制度处理后，GH648合金组织中的α Cr相析出量增加、尺寸长大；C制度对组织中γ′相的析出也有促进作用；另外，α Cr相的大量析出会导致GH648合金的冲击韧性变差。力学性能测试结果表明,C制度可使合金强度提高、塑性下降、冲击韧性急剧下降。     

GH648合金800 ℃长期时效后的组织稳定性

 研究了GH648合金在800 ℃×1 000 h下长期时效后的组织稳定性。结果表明：合金经800 ℃×100 0 h长期时效后，α Cr相的数量增加，尺寸长大，γ′相发生了聚集长大，合金中无有害相析出；合金的室温拉伸性能基本稳定，但高温拉伸强度和持久寿命下降；γ′相的聚集长大是致使长期时效后GH648合金高温拉伸强度和持久寿命下降的主要原因。     

碳对GH4199合金组织及拉伸性能的影响

采用金相显微镜和扫描镜研究了不同碳含量的GH4199合金的显微组织，采用拉伸实验测定了合金的室温拉伸性能，研究了碳含量对显微组织及拉伸性能的影响。结果表明，调整碳含量明显改变合金的晶粒度及碳化物的形状和类型，影响合金的室温拉伸性能；合适的碳含量可以阻止晶粒度长大，并且形成类球状的碳化物，有利于合金的强度、塑性的良好匹配。     

热处理对铸造Co—Cr—Mo合金性能的影响

本文主要研究热处理对铸造Co—Cr—Mo合金性能的影响，确定了C含量的佳值范围为0．25％～0．35％，冶炼母合金时，碳含量应控制上限，其硬度的佳值范围为HRC29～33，并采用热等静压、固溶处理和时效处理等工艺，为提高铸造Co—Cr—Mo合金人工关节的质量奠定基础。     

涡轮盘用GH4169合金真空感应熔炼脱硫工艺研究

通过对真空感应熔炼脱硫工艺的研究,采用CaO粉末前期脱硫,J—Ca后期脱硫的联合脱硫工艺。使涡轮盘用GH4169合金S含量降到0．0018％的较低水平,能满足S含量≤0．002％的要求,生产出合格的涡轮盘用GH4169合金。     

不同加工条件对预合金Fe—Mo粉末性能的影响

英国布雷德福大学机械与医学工程系M．Youseffi等人通过添加不同碳含量和不添加碳的方法制成预合金Fe－1．5Mo混合粉末并研究了其在不同加工条件下的烧结性能和机械性能。从而发现，碳含量，烧结温度和冷却速率高低对其物理、机械性能都有显著影响。其烧结密度亦随碳含量和烧结温度的增大而减低。而且，其极限抗拉强度（UTS）、抗弯强度（TRS）和硬度值也都随0．8％（质量分数，下同）C的添加量、烧结温度和冷却速率而增大。延伸率随碳含量和冷却速率的增加而降低，但烧结温度越高，其延伸率就越大。烧结态显微结构系由粗／细珠光体，大／小贝氏体及其混合体形态构成，但这要视其含碳量和冷却速率高低而定。含0．5％和0．8％试样的热处理机械性能有所改善。很明显，在烧结或热处理加工条件下亦可制得含Fe 1.5Mo 0.5-0.8C的多种三元低合金钢并用作具有良好物理、机械性能及高精度尺寸且含理想显微结构的PM结构部件材料。     

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。     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.