微量稀土Ce对Cu-Si-Ni合金性能的影响

采用非真空熔炼的方法制备了Cu-Si-Ni和Cu-Si-Ni-Ce合金,通过显微硬度和电导率测试等方法,对这两种合金的性能进行了研究,并探讨了微量稀土Ce对Cu-Si-Ni合金性能的影响。结果表明,微量稀土Ce的加入,能够提高Cu-Si-Ni合金的显微硬度,改善合金的导电性能;并明显细化了Cu-Si-Ni合金的晶粒。     

退火温度对钨铼合金组织和性能的影响

采用粉末冶金工艺制备了钨铼合金，通过拉伸性能测试、硬度测试、光学显微观察等手段，研究了退火温度对钨铼合金组织和性能的影响。研究表明：锻造后的钨铼合金室温抗拉强度为1620 MPa，断后伸长率为20%，维氏硬度为HV₃₀ 540。钨铼合金在1500℃时开始发生局部再结晶，1700℃时发生晶粒长大。钨铼合金的室温抗拉强度、维氏硬度随着退火温度的提高而降低，断后伸长率随着退火温度的升高先增大后减小。     

稀土Ce对3003铝合金组织性能的影响

在3003铝合金中添加不同含量的稀土Ce,研究Ce对铝合金组织性能的影响。采用SEM、EDS等方法对合金显微组织进行分析,并对合金维氏硬度进行测试。结果表明,3003铝合金中板条状组织为Al_4Mn,分布于黑色的Al基体上。随着Ce含量的增加,合金晶粒显著细化,且析出少量针状、片状或颗粒状白色组织Al_3Ce,同时合金显微硬度逐渐提高。当合金中Ce含量为0.35%时,合金固溶达到饱和;3003铝合金中最适宜的Ce含量为0.35%。     

La、Ce混合稀土对Al-0.75Mg-0.6Si合金组织性能的影响

采用金相显微镜、涡流导电仪和拉伸试验机,研究了La、Ce混合稀土对Al-0.75Mg-0.6Si合金组织、导电性能和力学性能的影响.结果表明:添加微量的La、Ce混合稀土对Al-0.75Mg-0.6Si合金可起到晶粒细化和净化作用,提高Al-0.75Mg-0.6Si合金的导电性能和力学性能.随着La、Ce混合稀土添加量的增加,Al-0.75Mg-0.6Si合金铸态组织晶粒逐渐被细化,电导率、抗拉强度和伸长率逐渐提高.当La、Ce混合稀土添加量为0.5!时,Al-0.75Mg-0.6Si合金的电导率为55.7!IACS,抗拉强度和伸长率分别为236 MPa和16.7!,与未添加La、Ce混合稀土相比,Al-0.75Mg-0.6Si合金的电导率提高了5.69!,抗拉强度和伸长率分别提高了11.32!和15.17!.     

固溶时效温度和冷变形对低含量Cu-Ni-Si合金组织性能的影响

以低含量Cu-Ni-Si合金为研究对象,采用光学显微镜(OM)、透射电镜(TEM)、硬度测试、导电率测试和室温拉伸性能测试等分析手段,系统研究固溶时效温度及冷变形量对Cu-Ni-Si合金固溶时效组织及性能的影响规律。研究结果表明:低含量Cu-Ni-Si合金经固溶+时效和固溶+冷变形+时效处理后,合金的抗拉强度与时效温度的关系曲线均呈单峰型,合金的导电率随时效温度的关系曲线均呈先快速上升后缓慢增加最后趋于稳定的趋势;对低含量Cu-Ni-Si合金施加冷变形和时效处理,可获得形变强化与时效强化的双重效果,显著提高合金的强度和导电率;随着冷变形程度不断增大,析出相析出越完全,合金的强度越高,但当低含量Cu-Ni-Si合金的冷变形程度提高至50%时,此时具有足够高的畸变能,相应的开始再结晶温度降低,此时时效强化与再结晶软化并存,导致合金的综合性能降低;合金经760℃×0.5 h固溶处理后,再经40%变形+480℃时效2 h后,可获得优异的综合性能,即抗拉强度为607 MPa,导电率为53%IACS。     

复杂锡镍黄铜合金加工硬化及再结晶温度的研究

对Cu-Zn-Sn-Ni合金进行了不同变形量的冷变形,绘制出了合金的加工硬化曲线.对退火后不同变形量试样的抗拉强度、硬度、延伸率及导电率进行测试和组织观察,确定了合金在不同变形量时的再结晶温度.结果表明,合金经冷加工变形后,具有明显的加工硬化效果,在80%变形量下,其强度可达590 MPa,延伸率为5. 6%,导电率为28. 2%IACS.合金的强度、硬度随变形量的增大,呈先增大后趋于稳定的趋势.而延伸率、导电率与变形量则呈相反的变化规律.此外,冷变形程度越大,合金的再结晶温度越低.     

微量稀土对铸态Cu-3.0Si-2.0Ni合金组织及性能的影响

加入适量的稀土元素能有效改善铜合金的组织和性能.铸态Cu-3.0Si-2.0Ni合金中添加稀土Ce后,进行熔炼及热处理试验,再通过室温拉伸、导电率试验和金相观察,研究了微量Ce对铸态Cu-3.0Si-2.0Ni合金组织与性能的影响.结果表明:铸态合金晶粒随着Ce含量的升高呈现先减小后递增的趋势;铸态合金的抗拉强度和导电性随着Ce的增加分别先升高后减低;当Ce的质量分数为0.06%时,铸态合金的抗拉强度最高、导电性最强.     

铈对铸造镁合金AZ91D显微组织与力学性能的影响

利用光学金相显微镜OM和XRD分析了分别加入0．1％，0．3％，0．5％，0．7％和1．0％Ce的AZ91D合金显微组织和相组成，测试了室温力学性能和硬度。结果表明，加入一定量Ce后的AZ91D合金形成杆状化合物Al4Ce，被推移到生长界面，阻碍枝晶的自由生长，从而细化合金显微组织；Ce能提高AZ91D合金室温抗拉强度和硬度，而对其屈服强度和延伸率影响不大；加入0．7％Ce的AZ91D合金晶粒细化效果好，其综合力学性能比较理想。     

稀土元素铈对镁合金AZ91D显微组织和力学性能的影响

利用光学显微镜、X射线衍射和扫描电镜等分析研究含铈镁合金AZ91D（0．25％Ce、0．7％Ce、0．95％Ce）的显微组织,并对其力学性能进行了测试,同时与不含铈镁合金AZ91D进行了比较。结果表明,加入一定量Ce后的镁合金AZ91D形成杆状化合物Al4Ce,被推移到生长界面,阻碍枝晶的自由生长,从而细化合金显微组织;Ce能提高镁合金AZ91D抗拉强度和硬度,而对其屈服强度和延伸率影响不大;加入0．7％Ce的AZ91D镁合金晶粒细化效果和综合力学性能比较理想。     

La,Ce混合稀土对挤压态工业纯铝组织性能的影响

以工业纯铝、Al-10%La中间合金和Al-15%Ce中间合金为原料,利用铝合金熔炼炉制备了Al-x RE(x=0,0.1,0.2,0.3,0.4,0.5;%,质量分数)合金。利用X射线衍射仪（XRD）、扫描电镜（SEM）,能谱（EDS）和背散射电子衍射（EBSD）表征合金相组成、显微组织和织构,通过万能试验机和显微硬度仪测量合金的强度和硬度,将组织、性能和织构进行对比,研究了La,Ce混合稀土对工业纯铝的影响。结果表明：随着稀土含量的增加,合金的平均晶粒尺寸逐渐减小;合金导电率随着稀土含量的增加呈现先增加后减小的变化趋势,其最大值为64.5%IACS,比工业纯铝提高了1%IACS;当稀土含量小于0.3%时,合金的力学性能变化较小,而当稀土含量超过0.3%时,合金的强度和硬度逐渐提高,平均抗拉强度最大值达到90 MPa,平均延伸率最小值为41.6%,平均硬度峰值为HV 24.9,其平均抗拉强度和平均硬度比工业纯铝分别提高了38.5%和19.1%,而延伸率仅降低了9.2%;随着稀土含量的增加,合金中<001>取向的晶粒逐渐减少,<111>取向的晶粒逐渐增多,合金中...     

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.