铝基体上化学镀Ni-P合金层组织结构的研究

对铝基体上形成的Ni-P合金镀层的组织结构进行了探讨,结果表明:非晶态Ni-P合金镀层以层片状沉积,表面具有胞状结构,镀层的磷含量及热处理温度对Ni-P合金层的组织结构有影响。     

影响化学镀Ni-P合金镀层耐蚀性的因素

综述了影响化学镀Ni-P合金镀层耐蚀性的各种因素,指出具有表面无缺陷、大小均匀、光滑的胞状组织及磷含量高的镀层耐蚀性才高.     

P含量对Ni-P镀层的性能影响分析

在Ni-P镀层中P含量对镀层性能有较大的影响。本研究以高速钢为基体材料,通过化学镀方式镀上不同P含量的Ni-P合金复合镀层。扫描电镜照片显示合金镀层呈胞状结构,颗粒均匀。X射线衍射图谱分析,高P镀层为非晶态结构,低P镀层为晶体结构;镀层的显微硬度以及耐磨性较基体材料有明显的提高;两种镀层的耐腐蚀性均优于基体材料;镀层结合力良好。     

乙醇酸络合剂电镀Ni-W合金工艺探究

电镀Ni-W合金常使用柠檬酸或其盐为络合剂.文中采用极少应用的乙醇酸络合剂制备了Ni-W合金镀层,研究了镀液组成和操作条件对镀层组成及显微硬度的影响.结果表明：钨含量对镀层显微硬度起决定作用,而镀液中Na2WO4浓度和电流密度会显著影响镀层中的钨含量,进而影响镀层的显微硬度,镀层的显微硬度最高可达615HV.通过正交实验得出适宜工艺条件为：NiSO4.6H2O12g/L,Na2WO4.2H2O 48g/L,C2H4O3.2 H2O 60g/L,pH6.5,镀液温度70℃,电流密度1.8A/dm2.     

电镀Ni-W合金的研究现状及发展趋势

综述了Ni-W合金的沉积机理,操作条件对镀层结构和性质的影响,介绍了Ni-W合金镀层与复合镀层的性质特点,并对未来的发展方向作出了展望.     

电沉积NiCoCr泡沫合金及其高温抗氧化性的研究

用电沉积方法制备了NiCoCr泡沫合金,研究了镀液组份对泡沫合金组分的影响,随着镀液中CrCl3.6H2O浓度增加,镀层Cr含量也增加;合金在不同的温度下进行了热处理,合金在617.85 oC、880.29 oC和1052.37 oC发生了相态转变;研究了热处理温度对合金的高温抗氧化性影响,在885 oC处理后,合金的高温抗氧化性能最好;同时还研究了合金中Cr含量对合金的高温抗氧化性的影响,随着Cr含量的增加,合金高温抗氧化性能增强.     

镍-磷-纳米二氧化钛化学复合镀工艺及性能研究

本实验用TiCl4水解法制备了纳米TiO2粉体,然后通过微粒最佳加入量实验确定了最佳工艺配方。采用最佳工艺进行施镀,并测量了镀液的寿命,最后对镀层的组织结构及各方面性能进行了测定。实验结果表明,纳米化学复合镀层的各方面性能要优于普通的镍磷镀层和微米化学复合镀层。     

新型Ni-P合金镀层材料的研究进展

通过对温度、pH值、搅拌方式等工艺参数在Ni-P合金镀层和Ni-P-PTFE(聚四氟乙烯)复合镀层中粒子分布和含量的影响,对化学镀层的重要性能,特别是耐磨性和耐腐蚀性进行了研究,总结了近年来国内外在化学镀层方面的发展情况,并对Ni-P-PTFE复合镀层和Ni-P合金镀层前景进行了展望。     

添加Sn、Ni元素对热浸镀锌钢的影响

采用SEM、BSE和EDS等技术研究了在锌浴中添加Sn、Ni元素后含0．36％Si钢热浸镀锌合金镀层的生长动力学及组织变化。结果表明：Zn—Sn—Ni合金浴法能够有效抑制含硅活性钢镀层的快速生长,获得厚度适宜、组织致密的镀层。     

Ni-W合金镀层在1mol/LH_2SO_4中的腐蚀行为

采用电化学综合测试仪和光电子能谱对几种成分的Ni—W合金镀层在1mol/LH2SO4中的阳极极化行为及表面组成物进行了测试分析．结果表明：Ni-W合金镀层在该介质中极易氧化,表面氧化物含量为94．28％随钨含量增加,其钝化区间加大     

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?     

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.     

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.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

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.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.