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1.
采用真空感应熔炼方法,制备了一系列Cu掺杂的MI(NiCoMnAlCu)5.0即AB50型贮氢合金.通过电化学及X射线衍射等手段,系统地研究和分析了Cu掺杂对AB50型贮氢合金的电化学性能(最大放电比容量、高倍率性能和循环稳定性能)及其微结构和动力学特征的影响.  相似文献   

2.
在AB5型贮氢合金MlNi3.55Co0.75Al0.3Mn0.4钴含量基础上,B侧采用Cu、Fe、Zn、Cr元素替代Co,A侧加入Dy来制备低钴贮氢合金.并对合金的放电容量、循环稳定性以及微观结构进行了研究分析.研究表明,通过调整合金成分可以使贮氢合金具有较好的组织均匀性和综合电化学性能.  相似文献   

3.
制备复合合金是改善贮氢合金性能的一条有效途径。本文对国内外各种多元以及多相稀土复合贮氢材料的研究现状进行了综合评述,主要涉及了AB5-AB2型复合贮氢合金和镁基-AB5型纳米复合贮氢合金的进展。阐述了各种复合材料的组成,微观结构以及电化学性能等,并展望了今后复合贮氢材料的研究方向为应用基础性的研究,如复合作用机制、对热力学性能的影响等方面的研究。  相似文献   

4.
周昱  朱惜林 《包钢科技》2005,31(2):35-38
通过在稀土系贮氢合金中添加不同含量的Fe或Cu元素,部分替代合金中Co的方法,研究低钴贮氢合金电化学性能上的差异.结果表明:由于合金组成和化学计量比的不同,同样是添加了Fe或Cu的合金在电化学性能上表现不同,但总体说,含Cu低钴贮氢合金容量和倍率放电性能较好,含Fe低钴贮氢合金有较好的循环稳定性,过化学计量比的合金循环稳定性要好于欠化学计量比的合金.  相似文献   

5.
陈丕生  王永光  曹慧 《包钢科技》2013,39(6):36-39,53
为了对比研究AB5型与AB3.5型贮氢合金的电化学及动力学特性,以AB5型MlNi3.68Mn0.32Co0.73Al0.27和AB3.5型Ml0.80Mg0.20 (NiMnAlCu)3.6、La0.6 Mg0.4 Ni3.5为研究对象.采用XRD分析了合金的相结构,利用电化学方法测试合金的电化学及动力学特性.结果发现,MlNi3.68 Mn0.32Co0.73Al0.27合金由单相LaNi5相组成,而Ml0.80Mg0.20(NiMnAlCu)3.6、La0.6Mg0.4Ni3.5均有LaNi5相和La2Ni7相组成.AB3.5型合金的放电容量、荷电保持率以及动力学特性高于AB5型合金.  相似文献   

6.
林振 《福建冶金》2023,(3):19-23
本文采用中频感应真空炉熔炼制备了掺杂锆、钇、钛元素的Mm(NiCoMnZrTiAl)5.15贮氢合金,熔体升温至1773K快淬为片状合金;在氩气气氛中1233K下保温10h,退火处理的贮氢合金粉碎至40μm进行性能测试。本文采用X射线衍射(XRD)、电子探针微区成分分析仪(EPMA)、PCT测试系统、电化学测试等研究方法系统研究了元素掺杂对Mm(NiCoMnZrTiAl)5.15贮氢合金微观结构、高温性能的影响规律。研究结果发现,Mm(NiCoMnZrTiAl)5.15系列贮氢合金均为Ca Cu5相;金属元素钇、锆、钛掺杂后锆元素在金相中有微量偏析;贮氢合金平衡氢压从1.7atm降低至0.45atm时合金高温性能提升,钇元素掺杂的HT-D合金放电容量最高为331mAh/g。HT-E合金钴含量增加后颗粒韧性增强,钇元素的掺杂提升了合金颗粒耐腐蚀性,因而具有最优高温性能。  相似文献   

7.
铝在新型稀土镁基AB3型贮氢电极合金中的作用研究   总被引:7,自引:0,他引:7  
宋月清  周增林  崔舜 《稀有金属》2006,30(1):114-117
借助于自制的开口式H型玻璃三电极测试体系,并在大量的前期实验工作基础上,研究了新型稀土镁基AB3型贮氢电极合金的性能以及添加Al的作用。发现用适量Al替代Ni可降低稀土镁基AB3型合金La0.7Mg0.3(Ni0.85Co0.15)3.5的氢化反应焓变和气态放氢平台压力,使合金氢化物变得更稳定;同时,使合金电化学循环100周期的容量保持率从63.8%提高到90.6%,有效解决了合金放电容量迅速衰减的难题;但Al的添加也降低了合金的最大放电容量、倍率放电性能和活化性能。  相似文献   

8.
AB5型贮氢合金结构分析   总被引:7,自引:3,他引:7  
贮氢合金的电极性能取决于贮氢合金的微结构。从晶体结构、电子结构及化学键结构等各方面对市场上广泛应用的AB5型贮氢合金的结构进行综述,同时讨论合金结构与合金吸放氢性能之间的关系。  相似文献   

9.
自从1990年前后小型MH-Ni电池商业化以来,镍氢电池的生产与销售都有了快速的增长。AB5型稀土镍系贮氢合金由于具有优良的性能价格比,是目前镍氢电池(MH—Ni)电池生产中实际应用最为广泛的负极材料。AB5型贮氢合金的放电容量已经达到一定的高度,目前,贮氢合金所需原材料金属Co及稀土元素钕和镨价格涨幅很快,因此拓宽MH-Ni电池的应用领域,提高其在电池领域的竞争力比较现实的途径是降低贮氢合金的生产成本。  相似文献   

10.
用真空熔炼、快淬工艺以及球磨工艺制备稀土基无钴AB5型La(NiMnAlFe)5贮氢合金,用XRD测试了合金的相结构,并测试了不同制备工艺下合金的电化学性能。研究了制备工艺对无钴合金的相结构和电化学性能的影响。结果表明,由真空熔炼和快淬工艺制备的合金为CaCu5型单相结构,球磨合金由CaCu5型相和游离Ni相组成,并出现了非晶化趋势。快淬和球磨均使合金的放电容量降低,循环稳定性提高,但球磨工艺的影响更为显著,主要原因是球磨后合金中出现非晶化趋势。  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
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。  相似文献   

12.
13.
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。  相似文献   

14.
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.  相似文献   

15.
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)  相似文献   

16.
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.  相似文献   

17.
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".  相似文献   

18.
张兴强  叶运福 《冶金设备》2005,(6):71-72,47
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。  相似文献   

19.
20.
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.  相似文献   

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