稀土Nd对铸造铝硅合金变质作用的长效性及重熔性研究

以稀土元素Nd为变质剂,采用金属型铸造工艺制备铸造铝硅合金ZL101,并通过金相显微镜、扫描电镜、布氏硬度计和电子万能试验机研究变质时间及重熔次数对合金显微组织和力学性能的影响.结果表明,稀土Nd对合金具有较好的变质作用,并具有长效性和重熔性,变质6h及重熔4次后合金中的共晶硅组织仍呈小片状的变质状态,且合金硬度及拉伸性能均未受明显影响.变质不同时间及重熔不同次数的合金拉伸试样均为解理断裂.     

稀土变质处理对提高FCB合金组织韧性的研究

针对FCB合金韧性不足的问题,研究了采用稀土变质处理的方法来改变硼化物在晶界的分布状态提高FCB合金韧性的措施.实验结果表明:稀土变质剂对FCB合金具有明显的变质作用.加入5％稀土变质剂后,合金中网状的耐磨硼化物转变为断网状或球团状,甚至颗粒状,细化了合金组织,韧性显著提高.     

Al-10Ce中间合金对ZL102共晶Al-Si合金的变质研究

分析研究了Al-10Ce中间合金对ZL102共晶铝硅合金的变质处理效果.结果表明,Al-10Ce中间合金用量、熔体中的杂质以及冷却速度对变质效果的影响很大,Al-10Ce中间合金用量为0.9%左右时达到最佳变质效果,提高Al-Si的纯度可以获得变质组织,冷却速度超过70℃/min时才具有明显的变质效果.     

RE-Ti复合变质对高钒高速钢组织和性能的影响

研究了RE-Ti对高钒高速钢铸态组织、热处理组织和性能的影响.结果表明,变质处理使高钒高速钢共晶碳化物的形貌和分布得到了改善,共晶组织中片层状碳化物变短、变细.热处理后,共晶碳化物大部分变成团球状且分布均匀.变质剂中的合金元素可促进晶粒中或沿晶界均匀分布的非连续状硬质碳化物的生成,从而达到改善组织、提高硬度的作用.并分析了变质剂在高钒高速钢中的作用机理及改善合金性能的机制.     

Al—10Ce中间合金对ZL102共晶Al—Si合金的变质研究

分析研究了Al—10Ce中间合金对ZL102共晶铝硅合金的变质处理效果。结果表明，Al—10Ce中间合金用量、熔体中的杂质以及冷却速度对变质效果的影响很大，Al-10Ce中间合金用量为0．9％左右时达到最佳变质效果，提高Al—Si的纯度可以获得变质组织，冷却速度超过70℃／min时才具有明显的变质效果。     

Al-5Ti-B对过共晶Al-18Si合金的变质效果

采用Al-5Ti-B变质剂对过共晶Al-18Si合金进行反向变质处理,用光学显微镜观察合金的组织与形貌,研究变质剂加入量、变质温度和冷却速度对初晶硅的尺寸、形态和面积分数以及共晶组织的影响。研究表明:当Al-5Ti-B加入量(质量分数)为0.3%时,变质处理后Al-18Si合金中的初晶硅和共晶硅尺寸明显减小,初晶硅的面积分数减小;与其相比,变质剂加入量增加到0.6%时,初晶硅尺寸变化不明显,但共晶硅进一步细化;随冷却速率降低,变质处理后Al-18Si合金中初晶硅相的数量减少,但Si颗粒尺寸明显增大,并且共晶硅细化;与Al-18Si合金在720℃变质相比,该合金在780℃变质处理时,初晶硅的尺寸增大,但初晶硅的面积分数显著减小;合金在850℃变质处理后初晶硅的尺寸、面积分数都比720℃变质处理后明显减小;随变质温度升高,Al-Si合金中的共晶硅明显细化。     

钛对ZA27合金组织和热疲劳性能的影响

研究了钛变质处理对ZA27合金的组织和热疲劳性能的影响.通过光学显微镜和扫描电镜观察试样的显微组织和热疲劳裂纹形貌,分析钛的变质机理和合金热疲劳损伤机制.结果表明:经钛变质处理后,ZA27的组织明显细化,初生α-A1相由粗大的树枝晶变为细小的花瓣状枝晶.合金塑性、韧性有较大幅度的提高,从而提高了其热疲劳性能.当Ti的添...     

硼对含Si蒙乃尔合金组织与性能的影响

在含Si蒙乃尔合金中添加微量B(硼)元素,研究B含量(质量分数)对含Si蒙乃尔合金组织及耐蚀性能的影响规律及机理,以期开发性能更佳的含硅蒙乃尔合金.通过金相显微镜观察合金的显微组织,根据电极化曲线分析合金的耐腐蚀性能.结果表明:在0～0.10%B范围内,随着B含量增加,合金枝晶组织开始细化,α(Ni)+β-(Ni3Si)共晶组织由网状向断网状发展,合金的腐蚀电位逐渐正移,腐蚀电流逐渐减小;B含量达到0.03%时,枝晶组织明显细化,共晶组织形貌呈断网状,此时合金的腐蚀电位最高,腐蚀电流最小;进一步增加B含量,枝晶组织开始粗化,共晶组织形貌又开始向网状发展,合金的腐蚀电位开始负移,腐蚀电流逐渐变大.合金组织明显细化及合金耐蚀性能提高的主要原因是微量B元素在合金中起到强变质剂作用.     

钇对铜和铜硅合金组织与性能的影响

用扫描电镜、能谱仪、Ｘ射线衍射、硬度测量等方法，研究了铜钇和铜硅钇合金的组织与性能。实验表明，钇的加入对铜和铜硅合金的组织有明显的变质作用，并提高了合金的硬度。     

变质处理对ADC12铸造铝硅合金组织及性能的影响

借助金相显微分析实验、拉伸实验等手段,研究不同含量的Al-10Sr变质剂对ADC12铸造铝硅合金组织及性能的影响,结果表明:添加变质剂后,ADC12合金的显微组织得到明显的细化,抗拉强度及延伸率得到极大提高,其中当采用w(Sr)为0.06%进行变质处理时其效果最佳。     

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。     

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.     

2008年中国电解金属锰发展态势浅析

对中国电解金属锰发展的市场态势、价格行情以及原材料供应情况作了初步分析,提出我国电解金属锰行业挑战与机遇并存,只要抓住机遇、迎接挑战、夯实基础、科技创新,电解金属锰行业前景将会更加光明。     

Replication of dimensions of locus of control.

Employed 120 male and 113 female undergraduates in a replication of H. L. Mirels's (see record 1970-10386-001) study which found 2 factors in analyzing responses to 23 items on Rotter's Internal-External Control Scale. The same polar dimensions of "luck" as the arbiter of life events as opposed to personal control were found as well as a 2nd dimension of degree of control over political and social institutions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rehabilitation of disorders of the breaking of voice

The adolescent's breaking of the voice is the result of the substitution of the chest voice (or heavy mechanism) for the head voice (or light mechanism). In cases of late breaking, the voice is abnormally high-pitched and feeble, often with a distorted timbre, while the larynx is normal and pubescent. Such people are generally not fully aware of their voices' real nature. Therapy classically resorts to laryngeal manipulations, of which a new technique is put forward. Another therapeutic approach is based, on the one hand, on critical listening compared with a control male voice, thus enabling the subject to become aware of his own voice, and, on the other hand, on high intensity work which helps passing from head to chest voice.