稀土氧化物纳米材料的制备方法综述

稀土氧化物纳米材料因其具有纳米材料和稀土元素的双重特性,引起了科学家的广泛关注.稀土纳米氧化物的合成与制备已成为世界各国科学家研究的热点之一.本文综合报道了国内外有关稀土纳米氧化物制备合成方法的研究进展.如:高温固相反应法、共沉淀法、溶胶一凝胶法、微乳液法、水热合成法、低温燃烧法、电化学法和气相法.对每种制备方法的优缺点进行了总结和评述,并对其应用前景进行了展望.     

湿法冶金渣中硫的化学回收

我国是个硫磺用量大国,硫磺生产小国.硫磺是一种重要的化工产品和基本工业原料,为了节约资源以及提高资源的利用率,重新回收各种湿法冶金渣中的单质硫是有必要的.硫的回收方法有很多,主要为物理法和化学法.物理法回收硫对设备和物料有较高要求,具有一定的局限性;而化学法能处理各种物料,在一定程度上弥补了物理法的不足.化学法除了常用的硫化铵法、二甲苯法、煤油法、四氯乙烯法外,还有硫化钠-二氧化硫法和新型脱硫剂法,比如四氢萘、苯乙烯、十氢萘和甲苯等;对于不溶性硫磺回收方法的研究也取得一定新的进展.文中介绍了各种化学法回收硫的原理及其优缺点.     

非灰气体离散坐标法模型的比较

将求解气体辐射传递方程的离散坐标法与描述非灰气体辐射特性的灰气体加权和模型结合,来研究气体介质参与的辐射换热问题.不同的坐标离散方法———SN法、TN法、SRAPN法与灰气体加权和模型结合,得到不同的非灰气体离散坐标法.分别用非灰气体的SN法、TN法、SRAPN法对一个三维炉况进行模拟,得到炉膛内介质的温度分布及壁面热流分布,比较了不同非灰气体离散坐标法的计算时间和精度.结果表明,SN法和TN法与灰气体加权和模型结合能较好地模拟气体介质参与的辐射换热问题.     

浅谈治疗失眠的自然疗法

目的:通过自然疗法,采取多种手段治疗失眠.方法:手疗法、足疗法、刮痧法、耳压法、点穴法、点穴法、香薰法、拔罐法及中医偏方多方法对失眠进行治疗.结论:自然疗法对失眠的治疗,无毒副作用,极大的提高了睡眠的质量,有利于失眠病情的缓解和恢复.     

基于AHP和CRITIC方法的水资源综合效益模型

分析了传统AHP法和CRITIC法存在的缺陷,结合AHP法和CRITIC法的优点,定义了综合赋权法.以天津市水资源供给方案为例,试验数值表明得到的结果与实际情况基本吻合.     

多组分稀土串级萃取有效分离系数的研究

提出了计算多组分稀土串级萃取有效分离系数的平均分数法,研究了稀土摩尔分数对有效分离系数的影响,比较了等效组分法、数学模型法、产品分数法和平均分数法的计算结果.研究表明,仅有平均分数法计算的有效分离系数均介于最大值和最小值之间,而且其极值均与理论极值相等.平均分数法具有更宽的适应范围和更高的准确度.     

不锈钢的纳米化工艺及其耐腐蚀性

叙述了不锈钢表面纳米化技术-表面机械研磨处理,喷丸法,异步轧制法和激光表面融熔法和不锈钢块体纳米化技术-机械合金法,惰性气体凝聚原位加压法,电化学沉积法,非晶晶化法和大塑性变形法.纳米化不锈钢的耐蚀性能直接受到纳米晶结构的影响,结构均匀,无位错,无应力是获得优异耐蚀性的前提.     

炼钢脱氧剂的研究进展

常用的脱氧方法有沉淀脱氧法、炉渣脱氧法和真空脱氧法,常用脱氧剂主要有锰、硅、铝、钛、硅铁、硅钙合金、SiCaBa复合脱氧剂和AlCaC.分别描述其作用及效果.     

千足黄金首饰的硬化工艺探讨

千足黄金首饰的硬化工艺是目前国内首饰行业关注的一个热点问题.根据金属材料硬化机理,结合黄金首饰不同生产工艺流程,提出了千足黄金首饰的硬化工艺为冶金法、渗氮法、纳米粉末法和电铸法,并对冶金法和渗氮法进行了探索性实验.实验结果表明,目前冶金法可实现千足黄金强度增大到维氏硬度85kg/mm2,渗氮法可增加到维氏硬度58kg/...     

打开语言理趣的金钥匙——浅谈语文教学中语感的培养

作为新世纪的语文教师,应把培养学生的语感摆在语文教学的核心地位.了解培养学生语感是语文教学的一个支点和重点.采用美文诵读法、品味词句法、联想想象法来培养学生的语感,从而有效地提高学生的语感能力和水平.     

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。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

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)     

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.     

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.