纳米表面合金膜修饰电极的制备、表征及电催化活性研究

以不锈钢(SS)作基底,自行研制不锈钢载纳米表面合金电催化材料(Surface alloy/SS),并运用循环伏安法(CV)和扫描电镜(SEM)等技术对该催化剂进行结构和性能表征。SEM研究表明,所研制的Surface alloy/SS电催化剂是一种由粒度主要约为100nm的颗粒合金组成的薄膜。循环伏安研究表明,所研制的Surface alloy/SS电催化剂在常温常压下对顺丁烯二酸的加氢还原表现出很高的电催化活性。顺丁烯二酸的起始还原电位为-0.4V,与通常用的阴极铅材料相比,正移约200mV。     

如何提高奥氏体不锈钢的切削加工质量

不锈钢材料的车削加工是机械工人培训的一个重要课题。在按金相组织分类的铁素体、马氏体、奥氏体三类不锈钢材料中 ,以奥氏体不锈钢材料的切削加工性能最差 ,所以 ,其车削加工质量的提高难度最大。奥氏体不锈钢材料的性能主要表现在以下几个方面。第一 ,塑性大 ,加工硬化严重 ,易生成积屑瘤而使加工表面质量恶化。切削力约比４５ #钢（正火）高２５ % ,加工表面硬化程度及硬化层深度大 ,常给下道工序带来困难。第二 ,导热系数小 ,只为４５ #钢的１／３ ,因此 ,加工时产生的热量多且不易导出 ,所以切削温度高。第三 ,由于切削温度高 ,加工硬…     

奥氏体不锈钢构件的腐蚀机理与焊接方法

基于奥氏体不锈钢材料越来越多的应用于不同的工业企业生产当中,为减少和避免加工过程中对材料原有优良性质改变,通过长期对其在船舶工业中的应用特点和工艺方法的实践研究,针对奥氏体不锈钢构件的抗腐蚀特性进行理论分析,揭示其工作在腐蚀环境中的抗腐蚀机理,并以焊接加工为例,指出不恰当的生产方法对奥氏体不锈钢的抗蚀特性的影响,提出了合理的工艺手段和改进措施。     

304不锈钢热处理工艺研究

借助洛氏硬度计和金相显微镜分别研究了304不锈钢中固溶处理和敏化处理热处理工艺。试验表明304奥氏体不锈钢加热至1000℃后并保温30min,经水冷后试样能够得到单相奥氏体,减少不锈钢晶界腐蚀,同时水冷后材料硬度较高。在敏化处理实验中,304不锈钢加热至750℃保温1h后,材料晶间腐蚀现象较为严重。     

加工奥氏体不锈钢工件铰刀的改进

南京轻工业机械厂提出铰削１Ｃｒ１８Ｎｉ９Ｔｉ奥氏体不锈钢工件的标准铰刀的刀具耐用度较低,一般只能加１１０～２０个孔,要求我校改进。经过我们的研究和试验,发现在标准铰刀上进行改磨几何参数和合理选择切削用量后,能使铰刀的刀具耐用度大大提高,可加工６０～７８个孔。仅此一种规格的饺刀,每年可节约上百把。加工表面粗糙度也从原来的１．６μｍ改善到０．８μｍ。现将试验结果介绍如下。１奥氏体不锈钢的切削加工性能１．１不锈钢的物理性能 １Ｃｒ１８Ｎｉ９Ｔｉ不锈钢是奥氏体不锈钢中最有代表性的一种,具有良好的抗蚀性和…     

胜过金属的“金属玻璃”

在大家的印象里,不锈钢是耐腐蚀不生锈的好材料。可是,如果将一种铁铬磷碳合金和不锈钢一起泡在强酸中,不锈钢变得“千疮百孔”时,它却完好无损。这种性能优异的合金,兼有玻璃和金属的     

胜过金属的“金属玻璃”

在大家的印象里,不锈钢是耐腐蚀不生锈的好材料。可是,如果将一种铁铬磷碳合金和不锈钢一起泡在强酸中,不锈钢会变得“千疮百孔”,而铁铬磷碳合金却完好无损。金属在高温下变成熔融状态,如果让它慢慢冷却,它就     

L_(316)氮化钛不锈钢复合体胫骨内种植的动物实验研究

用真空离子镀技术在L316医用不锈钢表面镀上一层氨化钛薄膜,制成氮化钛-不锈钢复合体,并以纯钛及医用L316不锈钢作对照,植入60只小白鼠的胫骨内．经扫描电镜等观察结果表明：氮化钛-不锈钢复合体及纯钛材料与骨之间都形成骨整合及纤维整合界面,但是,氮化钛-不锈钢复合体比纯钛材料骨性结合界面形成早,成骨活跃     

S31803双相无缝钢管全自动成型关键技术研究

S31803双相不锈钢的组织结构既有奥氏体又有铁素体,在性能上兼具奥氏体不锈钢和铁素体不锈钢的优点,占据无缝钢管领域主导地位,但因产品要求更加严格及存在着成型工艺上的弱势而影响了推广使用。通过在线窄焊缝自动焊接、在线自动切割、细长薄壁管内抛光等全自动成型的关键技术研究,成功研发了S31803双相耐高压无缝钢管全自动成型设备,解决了无缝钢管全自动成型的技术瓶颈。     

06Cr19Ni10奥氏体不锈钢晶间腐蚀的解析

分析了06Cr19Ni10奥氏体不锈钢产生晶间腐蚀的原理及影响奥氏体不锈钢晶间腐蚀的因素,介绍晶间腐蚀试验标准和常用试验方法,提出控制和减少奥氏体不锈钢晶间腐蚀的措施.氧化性的酸性腐蚀介质会加剧06Cr19Ni10奥氏体不锈钢晶间腐蚀;奥氏体不锈钢的敏化温度大约在427~816℃区间,其中对晶间腐蚀最敏感的温度是在650℃;晶间腐蚀的速度会随着奥氏体晶粒度的减小而减小;对晶间腐蚀影响最大的元素是碳元素.为此,合理调控化学组分,严格控制环境温度,进行固溶处理,控制晶粒度,提高其耐蚀性,降低由于晶间腐蚀导致的失效以及由此引发的安全事故.     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Social and Cultural Influence on Word Meaning

Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language.     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.