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1.
通过苯乙烯聚合制备了聚苯乙烯微球胶体,采用浸渍-提拉制备成为紧密堆积的PS球胶晶模板,微球之间的间隙采用溶胶-凝胶法制备的WO3溶胶填隙,最后通过煅烧得到有序规则排列的多孔WO3薄膜。通过XRD、SEM对WO3多孔薄膜的结构及形貌进行了表征,并评价了薄膜的光催化性能。结果表明,在450℃高温下煅烧PS模板,得到有序排列的多孔WO3薄膜,平均粒径为150nm,光催化效率最高。  相似文献   

2.
采用溶胶-凝胶技术与PS微球模板相结合,在铝基板上成功制备了亚微米连续蜂窝网状LiFePO4薄膜。采用XRD、SEM等测试手段对薄膜的组成及显微形貌进行了表征,研究了成膜工艺、涂膜方法及模板球直径等因素对薄膜形貌的影响规律,并对薄膜形成机理进行了初步探讨。结果表明,成膜过程中模板表面溶胶层与模板之间的作用力是影响薄膜结构的关键因素;对于600nm PS球模板和200nm PS球模板获得完好LiFePO4薄膜的最佳方法分别为浸渍提拉法和旋涂法。  相似文献   

3.
以无皂乳液聚合方法自制的单分散聚苯乙烯(PS)微球乳液为原料,利用PS自组装制备了有序胶体晶体模板("蛋白石"),采用溶胶-凝胶模板法制备了有序大孔TiO2微球("反蛋白石"),其孔呈六边形,孔径分布均一,约为200nm。运用扫描电镜(SEM)、X射线衍射(XRD)对其形貌特征及晶型进行了表征,结果表明,采用表面含有羧基的单分散聚苯乙烯微球及高的硅油黏度制得的模板有序度高;通过控制煅烧温度可以改变有序大孔TiO2微球的晶型,当煅烧温度为500℃时,其晶型为锐钛型,当煅烧温度为700℃时,其晶型则为金红石型。  相似文献   

4.
分别采用浸渍一提拉法和液相渗透(LPI)法用SnO2前驱物填充模板得到SnO2/PS复合膜,灼烧去除模板后,成功地制备了三维有序多孔SnO1膜.PS胶粒晶体模板是用乳液聚合法合成的单分散PS微球通过垂直沉积法在55℃组装而成.实验结果显示,由改进的LPI法制备的三维有序多孔膜质量相对较高,面积较大并且无"表皮"覆盖.在灼烧去除模板的过程中孔径有一定的收缩.  相似文献   

5.
通过乳液聚合得到了单分散的聚苯乙烯(PS)微球乳液并通过阳离子破乳沉降法实现PS微球自组装,得到了紧密堆积的PS微球的胶体模板剂。向PS胶体模板的空隙填充硅溶胶,再通过焙烧去除模板得到三维有序大孔(3DOM)二氧化硅(SiO_2)材料。采用扫描电子显微镜、透射电子显微镜、红外和热重分析等对合成的3D大孔SiO_2材料进行表征。结果表明:使用粒径不同的PS微球作为模板,制得的3D大孔SiO_2材料的孔径在200~400nm之间。该制备方法为多孔材料的制备开拓了一条可行、便捷的途径。  相似文献   

6.
以P123为介孔模板、以Zn(Ac)2·2H2O和LiOH·H2O为原料制备ZnO前驱体溶胶,对聚苯乙烯(PS)微球模板进行填充,55℃干燥后形成凝胶。经过600℃高温煅烧除去有机模板剂P123和PS,从而得到了具有介孔/大孔分级结构的ZnO材料。采用扫描电子显微镜、傅立叶变换红外光谱仪对分级孔结构ZnO材料进行了表征,并研究了其电致发光性能。结果表明,相同条件下介孔/大孔分级结构ZnO材料的发光强度是介孔ZnO材料的3.3倍。  相似文献   

7.
采用乳液聚合法制备了单分散P(St-AA)微球,经自然沉降法制成胶体晶体模板,再利用胶晶模板法制备了有序多孔堇青石.利用FTIR、SEM、DSC、XRD等方法对P(St-AA)微球单分散性及有序多孔堇青石结构进行了研究.结果表明,当AA用量占单体总量的5.0%时,制备的P(St-AA)微球的单分散性及其胶体晶体微球结构最佳.经烧结去除P(St-AA)微球得到的有序多孔堇青石材料的孔径较单分散P(St-AA)微球稍小,约为200nm左右.当烧结温度为1200℃,多孔材料为堇青石相.  相似文献   

8.
采用溶胶-凝胶法和胶体晶体模板法制备了有序多孔TiO2微球,在微波辐照条件下对其掺氮改性,利用FTIR、SEM、XRD、XPS分析等方法对掺氮TiO2材料进行表征,并研究掺氮前后TiO2材料的光催化性能。实验结果显示,所制备有序多孔TiO2微球整体较致密,但局部有孔洞塌陷。微波辐照前后有序多孔TiO2微球的晶型没有改变,依然为锐钛型。XPS分析发现微波辐照制备掺氮有序多孔TiO2微球是可行的,且有序多孔TiO2微球中氮元素质量分数约为1.24%。掺氮有序多孔TiO2微球的光催化性能好于未掺氮TiO2的光催化性能。  相似文献   

9.
采用低温垂直沉积法制备了聚苯乙烯(PS)胶体模板,由于低温下粒子热运动受到抑制,排列时发生位错,因此模板中存在大面积四方排列结构。然后采用化学镀法、溶胶-凝胶法在PS微球表面依次沉积银纳米粒子、纳米TiO2,最后高温煅烧除去模板制备了四方排列有序Ag/TiO2空心微球。通过扫描电镜(SEM)、X射线衍射(XRD)对样品进行表征。结果表明这种材料很好地保持了模板的四方排列,具有高度有序的纳米结构。选择降解甲基橙溶液来检验样品的光催化性能,并与纳米TiO2薄膜、四方排列TiO2空心微球的光催化性能进行比较,结果表明四方排列Ag/TiO2空心微球具有最佳的光催化性能。这是有序空心纳米结构和银纳米粒子的沉积共同作用的结果。  相似文献   

10.
胶晶模板法制备三维有序多孔羟基磷灰石   总被引:1,自引:0,他引:1  
采用stber法制备SiO2胶粒,经自然沉降的过程制备SiO2有序模板,再通过HA前驱体溶胶灌注、烧结和碱液浸渍等过程,制备了三维有序多孔羟基磷灰石(HA).采用XRD、TEM、FESEM和Zeta电位对样品的物相、微观结构、孔分布及表面电性能进行研究.结果显示,H2O2表面改性使得SiO2胶粒Zeta电位升高,有利于提高模板的有序性.制备的SiO2胶粒粒径约为250nm,由胶粒形成的多孔羟基磷灰石的孔径约为200nm,孔间由孔径约为20nm的微孔互相连接.此外,还考察了羟基磷灰石前驱体浓度、用量以及碱液浸渍时间对多孔材料的成型、孔结构、孔隙率的影响.当使用的前驱体浓度为0.8mol/L,用量占模板体积的30%,浸渍在4mol/L 的NaOH中3d后,形成的多孔HA有序性良好.  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  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.
14.
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...  相似文献   

15.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

16.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

17.
ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.  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.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

20.
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from  相似文献   

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