羰基法生产纳米镍粉

本文介绍了羰基法生产纳米镍粉的主要工艺过程 ,纳米镍粉的性能。分析了羰基镍蒸气浓度、热解温度、稀释比、离解所需热量供给方式对纳米镍粉的粒度等性能的影响。并对发展我国纳米镍粉提出了讨论意见     

多层陶瓷电容器用球形纳米镍粉的研究进展

综述了多层陶瓷电容器内电极浆料用球形纳米镍粉的制备方法,这些方法包括液相化学还原法、喷雾热解法、多元醇法、等离子体法、羟基镍法等。介绍了MLCC用纳米镍粉的表面改性技术,并提出了MLCC用球形纳米镍粉的发展方向。     

纳米镍粉制备技术研究进展

纳米镍粉是一种重要的金属粉末,具有广泛的用途.论文介绍了目前国内外制备超细/纳米镍粉的新工艺、新方法,并将这些制备方法进行对比,讨论了每种制备方法的优缺点,对存在的问题做了分析.展望了纳米镍粉的制备技术及其应用前景.     

含纳米镍粉的超细陶瓷涂层材料的显微结构和摩擦性能研究

在超细陶瓷涂料中分别添加了不同含量的纳米金属镍粉,采用流涂方法在GH202镍基合金表面制备了含纳米镍粉的超细陶瓷涂层.用扫描电镜及透射电镜观察和分析了纳米金属/超细陶瓷涂料中纳米颗粒的尺寸和微观形貌以及在涂层中的分布情况;通过摩擦实验评价了涂层的耐磨损性能.结果表明:涂层中的纳米颗粒趋于靠近涂层/基体界面处分布;在900 ℃保温2h过程中,涂层中纳米颗粒没有明显的长大;添加纳米金属镍粉可以明显提高涂层的耐磨损性能,随纳米镍粉含量的增加,涂层的耐磨损性能提高.     

兰州大学成功研制出纳米镍粉

在发射卫星用的火箭固体推进剂中 ,加入约 1 %的纳米镍 ,就可使其燃烧值增加 2倍。兰州大学的科技人员在实验室成功研制出了这种纳米镍粉。超细镍粉是一种纳米金属材料 ,具有一系列独特的物化性质 ,在催化剂、电池材料及硬质合金粘结剂等许多领域都有广泛的应用前景。以纳米镍制成的复合催化剂可使有机物加氢或脱氢反应的效率比传统镍化剂提高 1 0倍。据了解 ,兰州大学的科研人员选用简单廉价的液相还原法 ,并对此进行了多年系统研究 ,成功地研制出了十几到几十纳米的超细镍粉。目前 ,国际市场上的纳米镍粉售价在 1万元 /kg ,而兰州大学实验…     

我国羰基镍工业的技术进步

本文试图从羰基镍产品 (纳米级镍粉、微米级镍粉、气相沉积复合粉 )的研究与开发、羰基镍生产设备与工艺、安全生产要点等方面小结我国羰基镍工业的技术进步     

纳米镍粉的粒度分析

纳米材料的性质强烈依赖于其颗粒和晶粒的大小，测量纳米颗粒或晶粒尺寸无论从粉体制备还是从应用上都具有重要的意义。本文针对纳米镍粉进行了一系列粒度分析研究，包括SEM、TEM、激光粒度分析法、比表面分析法、X射线衍射法和X射线小角度散射法(SAXS)。不同的研究手段得到的纳米镍粉的粒径不尽相同。比较各种研究手段得到的结果可以知道其准确程度，并且针对不同的分析要求可选择不同的方法。     

纳米金属钴粉或镍粉的制备方法

中国科学技术大学研究开发出一种纳米金属钴粉或镍粉的制备方法。它将钴盐或镍盐重量 2～ 5倍的ＮａＯＨ加入到钴或镍离子摩尔量 3倍以上的水合肼溶液中 ,再与钴盐或镍盐的醇 水溶液混合均匀 ,反应即自动进行。所得纳米钴粉或镍粉具有很好的磁学性能和催化性能。该方法原料价廉易得 ,设备工艺简单 ,无需加热 ,高效快速 ,一步完成 ,产率高 ;母液可重复利用 ;利用该方法可对粒子进行表面包覆修饰。纳米金属钴粉或镍粉的制备方法@耀星     

催化热解聚丙烯塑料制备纳米碳管

以聚丙烯母粒为原料,纳米镍粉为催化剂,催化热分解法制备了碳纳米管。应用X—射线衍射、透射电镜对制备的纳米碳管进行了粒度测定、形貌观察。纳米碳管为丝状缠绕在一起,直径在20~30 nm之间,纳米碳管的d002值为0.338,具有较高的可石墨化度。应用热重分析方法准确测定了纳米碳管和无定形碳等碳杂质分离的煅烧温度。本实验得到的纳米碳管在600~730℃区间相对稳定,氧化温度大于730℃,则纳米碳管被氧化。     

激光辐照石墨-镍悬浮液制备碳包覆颗粒的研究

用球磨机湿法球磨微米级镍粉和石墨制备石墨与镍的悬浮液,然后用脉冲激光辐照.用扫描电镜、X射线衍射和透射电镜等对球磨和激光辐照后的产物进行表征.结果表明:球磨细化了镍粉,并使镍粉和石墨混合均匀,使其可悬浮于水介质中;然后激光辐照悬浮液得到了细小的碳包覆镍纳米颗粒.通过对碳包覆颗粒形成机制的初步探索,认为激光作用会使镍和碳气化并形成镍碳混合蒸气,在脉冲过后的冷却过程中碳和镍碰撞溶解,而温度的不断降低会促使过饱和的碳从镍中析出,从而形成包覆,获得了细小的碳包覆颗粒.     

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。     

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。     

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.     

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.     

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。     

参与式农业基地建设行动方案设计

为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.