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1.
石墨—碳化硅复合材料及其制法(特公平5-83517)专利权限这是关于石墨—碳化硅复合材料的制造方法,权限如下:1、在石墨基体材料表面浸渍占石墨基体材料全气孔体积5~60%的碳化硅,以及在此碳化硅浸渍层上进一步形成碳化硅包覆层。2、让溶融硅浸透并反应,...  相似文献   

2.
新型的光致发光高分子材料耿奎士(天津商学院300400)光致发光高分子材料自八十年代问世以来发展速度相当迅速,现在已具有较广泛的应用范围,这与它本身的特性是分不开的。因为这种材料具有在日光、紫外光或其它光源激发下储存能量,而后以发光的形式缓慢释放能量...  相似文献   

3.
相变储能混凝土的研究   总被引:2,自引:0,他引:2  
相变储能技术对能源的开发和合理利用具有重要意义,在太阳能利用、工业余热回收等方面有着显著的优点.相变储能材料能将暂时不用的能量储存起来,到需要时再将其释放,这就可以缓解能量供与求之间的矛盾,节约了能源.通过把制备的活性炭储能骨料和石墨导热功能基元材料加入混凝土中,取代其中的卵石和河砂,用普通混凝土的制备技术制备相变储能混凝土.实验结果表明,活性炭储能骨料的加入使混凝土中储存了大量的相变材料,制得的储能混凝土的比热容明显高于普通混凝土,石墨提高了其导热系数,但活性炭储能骨料和石墨的加入导致制品的抗压强度下降剧烈.红外光谱证实储能混凝土中的相变材料没有同其它物质反应,因此具有良好的储能效果.  相似文献   

4.
热丝法低温生长硅上单晶碳化硅薄膜   总被引:4,自引:0,他引:4  
提出了热丝化学气相淀积法,在低温(600-750℃)下成功地生长出硅上单晶碳化硅薄膜,X光衍射谱、喇曼光谱证实了外延膜的单晶结构,光致发光测量证明外延SiC材料室温下可稳定发射可见光。  相似文献   

5.
张俊萍  王华  张存  宋春丽  李娟  郝玉英  周禾丰  许并社 《功能材料》2011,42(Z4):738-740,743
以有机电致发光材料-8-羟基喹啉铝(Alq3)为研究对象,在其表面包覆SiO2来改善有机电致发光器件中的材料界面,从而延长器件寿命.利用透射电子显微镜、光致发光光谱、热重分析分别对产物的形貌、发光性能和热稳定性进行了表征,借助扫描电镜和X射线光电子能谱仪对产物的薄膜进行了微观分析,分别以Alq3和包覆了SiO2的Alq...  相似文献   

6.
铜-石墨自润滑触头材料的研究进展   总被引:5,自引:0,他引:5  
综述了铜-石墨滑动触头材料的研究进展,包括制备工艺、石墨含量、石墨粒度、添加组分和化学镀铜包覆石墨因素对铜石墨材料性能的影响以及铜石墨材料的摩擦学问题,最后指出了铜石墨自润滑触头材料的发展趋势.  相似文献   

7.
应用水热法制备了立方相ZnS,通过均匀沉淀法得到ZnO包覆的ZnS颗粒.简单介绍了包覆的原理,对样品进行了XRD、SEM和光致发光光谱PL表征.结果表明,应用不同的表面活性剂可得到形貌各异的样品.  相似文献   

8.
采用碳热还原法以及沥青裂解包覆技术,制备具有核壳结构的Sn/C复合负极材料,对采用改性天然石墨与人造石墨作为内核的效果作了比较,并分析研究壳层的厚度对材料综合性能的影响.结果表明,采用改性天然石墨作为内核能更有效分散Sn金属颗粒,另外沥青裂解碳包覆层的厚度对材料的循环稳定性具有较大的影响.以改性天然石墨为内核,具有(10%+20%)双层包覆结构的负极样品具有最佳的综合性能,首次库伦效率为76.3%,54周的容量保持率为99%.材料结构的设计以及结构的合成工艺是解决锡基合金负极材料体积效应的重要途径.  相似文献   

9.
氧化锌包覆纳米碳化硅的制备   总被引:1,自引:0,他引:1  
为了解决纳米碳化硅的应用问题,采用溶胶-凝胶法制备出氧化锌包覆纳米碳化硅颗粒,并对其前驱物的煅烧工艺进行了研究.借助差热-热重分析仪(TG-DSC)、X射线衍射分析仪(XRD)、红外光谱(FT-IR)、高分辨透射电镜(HRTEM)和能谱仪(EDS)等测试手段,发现经500℃煅烧2h后,产物的包覆层从水合草酸锌被煅烧成为氧化锌;氧化锌峰形尖锐,结晶良好,被覆物SiC的峰相对变弱;包覆产物的红外谱图上出现了Zn-O特征吸收峰,煅烧生成的10—20nm氧化锌颗粒较好地包覆在大粒径的碳化硅颗粒周围.  相似文献   

10.
研究了碳化硅和石墨含量对碳化硅/石墨双层复合材料介电常数实部、虚部、损耗角正切的影响。鉴于该材料多用于工程领域,测试了该复合材料的弯曲、剪切、拉伸等力学性能。结果表明:在低频段,该材料介电性能良好,碳化硅含量、石墨含量均对涂层复合材料的实部、虚部和损耗角正切影响较大;当碳化硅含量为24%,石墨含量为60%时,涂层复合材料的介电常数实部、虚部最大,其极化和损耗能力最强。另外,该复合材料具备良好的力学性能,最大弯曲强力为48.3N,最大剪切强力为57.5N,最大拉伸强力为618N。  相似文献   

11.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

12.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

13.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

14.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

15.
We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.  相似文献   

16.
Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.  相似文献   

17.
ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.  相似文献   

18.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

19.
As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.  相似文献   

20.
TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.  相似文献   

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