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1.
为探讨分散剂对液相化学还原法制备超细铜粉的影响,分别以明胶、焦磷酸钠、聚乙烯吡咯烷酮、高分子聚合物A作为表面分散剂,采用液相化学还原工艺制备出不同形状、不同尺寸的超细铜粉。利用XRD、SEM及激光粒度分析仪等手段对所制备的超细铜粉的物相、形貌及粒径大小进行了分析。研究结果表明:不同的表面分散剂对采用液相化学还原法制备的超细球形铜粉的作用是不同的;使用高分子聚合物A可以制备出球形度好、结晶度高、粒径分布窄和抗氧化性好的超细铜粉。  相似文献   

2.
采用PEG辅助溶剂热法,通过添加表面活性剂(HMTA、CTAB、PVP)制备不同形貌的ZnO纳米棒.系统研究了ZnO纳米棒对乙醇气体的敏感特性.结果表明,添加表面活性剂调节ZnO纳米棒形貌可有效改善其对乙醇的气敏响应特性,其中添加六亚甲基四胺制得的ZnO纳米棒在340℃对体积分数100×10~(-6)的乙醇气体非常敏感,其灵敏度高达67,较未添加表面活性剂的ZnO(S=35)提高了约91%.  相似文献   

3.
文章探讨了一种Ni-PTFE的化学复合镀工艺,着重讨论了各种工艺条件和后期处理对镀层性能的影响,并对所得镀层的性能进行了测试。结果证明,后期处理对镀层的硬度和耐磨性有较大影响,温度、PH值、表面活性剂对镀层的组成,性能和表面形貌有着较大影响。  相似文献   

4.
为了提高麦谷蛋白的酶解效率,采用超声波-离子液体预处理麦谷蛋白.在单因素影响试验的基础上,以水解度为响应值,采用响应面法对超声波-离子液体辅助麦谷蛋白酶解工艺条件进行优化,并对最优条件下麦谷蛋白酶解产物的抗氧化活性进行分析.结果表明,各因素对麦谷蛋白水解度的影响从大到小依次为:水/离子液体体积比、超声波功率、料液质量浓度、超声波处理时间.超声波-离子液体辅助麦谷蛋白酶解的最优工艺条件为:超声功率287. 7 W、超声时间6. 3 min、水/离子液体体积比值0. 85∶1、料液质量浓度20 g/L,在此条件下,麦谷蛋白水解度实际值为10. 67%±0. 046%,与预测值基本一致.抗氧化试验表明,超声波-离子液体处理后,麦谷蛋白酶解产物清除1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基能力和螯合Fe2+能力分别比处理前提高了28. 45%和14. 52%,其还原力也得到了改善.  相似文献   

5.
选用表面活性剂聚乙烯醇缩丁醛(PVB)和聚乙烯吡咯烷酮(PVP),以及偶联剂KH550、KH570等表面处理剂,来研究体系中添加表面处理剂对溶剂热法合成的CuInS2纳米晶体分散性的影响.利用X-射线粉末衍射仪、EDS能谱、扫描电镜(SEM)和紫外-可见近红外分光光度计对纳米晶体的结构、原子配比、形貌和光吸收性能等进行表征.结果表明:体系中添加少量(总质量的0.1%)表面处理剂制备的CuInS2纳米晶体团聚现象能得到有效改善,其中偶联剂KH570和表面活性剂PVP改性效果佳.  相似文献   

6.
以水溶性的有机碱为主要成分,自制LHA为缓蚀剂,2-乙基己醇/吐温复合体系为表面活性剂制备新型水基清洗剂.利用电化学交流阻抗(EIS)技术比较了缓蚀剂加入前后铝在清洗剂中的腐蚀情况,并通过正交实验法讨论了清洗剂中各组分对清洗效果和缓蚀效果的影响.结果表明,有机碱的质量分数占清洗剂体系的75%,缓蚀剂占体系的5%时,可达到较好的清洗与缓蚀效果.  相似文献   

7.
刘显杰  徐磊  李代颖  程耿 《船电技术》2013,33(7):33-35,38
采用化学还原法制备了超细铜粉,以CuSO4为原料,对用NaOH沉淀-葡萄糖预还原-水合肼还原工艺制备的超细铜粉进行了研究。结果表明:两步法添加水合肼时,第一步和第二步添加用量比例为1:4,反应温度为70℃时,得到铜粉粒径最小,为2.484μm,铜粉颗粒形貌近球形,比表面积为1.9m2/g,振实密度为2.5g/cm3。  相似文献   

8.
张轶  游立  李玉龙  周阳宁  桂苗  邢滔 《船电技术》2023,(4):22-25+30
本文主要采用液相化学还原法制备不同形貌、粒径大小的超细铜粉,采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、激光粒度分析仪进行表征,研究不同种类还原剂对超细铜粉形貌尺寸、粒度分布及粒径大小、振实密度的影响。结果表明,采用葡萄糖-抗坏血酸分步还原法制得平均粒径约1.30um超细铜粉,中高振实密度、分散性好、球形度佳、无明显团聚,粒径大小均一且呈现窄粒径分布特点。  相似文献   

9.
以纯度99.5%的NaC1配制的5%中性溶液为腐蚀加速溶液,对经热处理工艺和3种不同防护涂料保护的22MnCrNiMo系泊链钢进行连续盐雾加速实验,研究了热处理工艺对腐蚀试样表面腐蚀产物、表面形貌及腐蚀率等的影响.结果表明:盐雾加速腐蚀实验结果与电化学测试结果一致,该实验具有较好的加速性和模拟性.系泊链钢经930℃二次...  相似文献   

10.
本文系统地阐述了液相还原法制备超细铜粉的工艺及研究进展,重点介绍了一步还原法和两步还原法过程中还原剂对铜粉制备过程的影响,指出了目前液相还原法制备超细铜粉中面临的难题和存在的问题,并提出了建议.  相似文献   

11.
Errata     
正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.  相似文献   

12.
13.
正San Francisco,California,June 8-13,2014.OMAE 2014 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to:·meet and present advances in technology and its scientific support;·to exchange ideas and experiences whilst promoting technological progress and its application in industry·to promote international cooperation in ocean,offshore and arctic engineering.In line with the tradition of excellence of previous OMAE conferences,more than 900 technical papers are planned for presentation.Outreach for Engineers Specialty Forum This Specialty Forum is designed for students and professionals who may not be familiar with the Ocean and Offshore industry,as well as those who have just recently specialized in this field.  相似文献   

14.
联合作战计划和执行系统   总被引:2,自引:1,他引:1  
全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划:时间不限的精密预案计划生成作战计划、方案计划或职能计划;时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础,加速应付危机的能力。  相似文献   

15.
Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.  相似文献   

16.
正19–24 October 2014 SingaporeCONFERENCE THEMES The overall aim of the ICHD Conference is to provide a forum for participants from around the world to review,discuss and present the latest developments in the broad discipline of hydrodynamics and fluid mechanics.The first International Conference on Hydrodynamics(ICHD)was initiated in 1994 in Wuxi,China.Since then,9 more ICHD conferences were held subsequently in Hong Kong,Seoul,Yokohama,Tainan,Perth,Ischia,Nantes,Shanghai and St Petersburg.Evidently the ICHD conference has become an important event among academics,researchers,engineers and operators,working in the fields closely related to the science and technology of hydrodynamics.The 11th ICHD will be held in Singapore in 2014.  相似文献   

17.
正November 4-6,2014Moody Gardens HotelConvention Center/Galveston,TX The Deepwater Operations Conference and Exhibition is celebrating its 12th anniversary this year.This growing event will continue the tradition of excellence in addressing operational challenges involved in developing deepwater resources.We will return to the Moody Gardens Hotel and Convention Center on November 5-7,2014 in Galveston,Texas.  相似文献   

18.
In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama?
The answer is China South Port Group (Hong Kong, Shenzhen and Guangzhou).  相似文献   

19.
Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.  相似文献   

20.
依据码头撞击受损区域调查检测结果,对受损构件提出合理的修复方案,为码头的安全运行提供保障。  相似文献   

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