负载型TiO2光催化薄膜结构控制及光催化活性

采用溶胶-凝胶法在不锈钢丝网上负载TiO2薄膜,通过SEM、XRD和TG-DTA对其进行表征.研究了聚乙二醇(PEG)分子量及添加量、水加入量、涂膜次数和煅烧温度等工艺条件对样品光催化降解甲醛性能的影响.结果表明,通过工艺条件控制可得具有较高光催化活性的负载型TiO2光催化薄膜.在钛酸丁酯乙醇溶液中添加适量PEG600和水,经反应制备的TiO2溶胶,涂膜于不锈钢丝网表面,450℃煅烧后获得具有中孔结构的TiO2混晶薄膜,该薄膜对甲醛光催化降解率达90%以上.     

纳米TiO2薄膜光催化剂的制备及性能研究

以钛酸四丁酯作为前驱体,用溶胶一凝胶法,在玻璃载体上煅烧制备了纳米TiO2薄膜光催化剂,利用扫描电子显微镜（SEM）、X射线衍射（XRD）等表征技术研究了TiO2薄膜的形貌和特性,其光催化性能用4支20W紫外石英杀菌灯照射TiO2薄膜分解亚甲基兰染料溶液表征,结果表明,该催化剂具有锐钛班红石混合晶相和纳米花状结构,纳米TiO2薄膜的光催化能力随着镀膜层数的增加而增加。     

PEG辅助的溶胶凝胶法制备多孔ZnO薄膜

以醋酸锌为前驱体,乙醇为溶剂,二乙醇胺为络合剂,通过聚乙二醇(PEG)辅助的溶胶--凝胶法在玻璃基片上制备了ZnO多孔薄膜.利用IR、TG-DTA、XRD及SEM等测试方法对薄膜的结构和特性进行了分析.探讨了样品在溶胶-凝胶及煅烧过程中的物理化学变化.研究了前驱体浓度、PEG2000加入量对薄膜结构和性能的影响.结果表明,当Zn2 的浓度为0.6mol/L的溶胶在70℃水浴时,加入PEG2000后,有利于ZnO多孔结构的形成,而且孔尺寸及密度也随PEG加入量的增大而增大.     

纳米TiO2薄膜的制备及其表面形貌AFM观测

采用溶胶-凝胶法在玻璃载波片及ITO导电玻璃片上制备出负载型纳米TiO2薄膜,并用原子力显微镜(AFM)对不同条件下制备的TiO2的表面形貌进行了表征.结果表明,TiO2薄膜能较好地负载在玻片表面,并且TiO2薄膜的表面形貌与前驱物的配比浓度、基片、热处理温度等都有密切的关系.随浓度和镀膜层数的增大,薄膜中TiO2纳米微晶的颗粒尺寸逐渐增大,从细小均匀粒子膜变为较大不规则的板块结构.在ITO薄膜面形成的TiO2薄膜具有较小的颗粒和均匀的分布.     

纯Mg表面TiO_2薄膜的耐蚀性研究

以四氯化钛为前驱体,去离子水为溶剂,盐酸为抑制剂,采用溶胶-凝胶法制得TiO2溶胶。采用浸渍-提拉技术在纯镁基体上制得TiO2薄膜,以提高纯镁基体的耐蚀性。通过正交实验,以电化学阻抗值作为评价标准,研究了热处理温度、涂层次数、溶胶浓度对试样耐腐蚀性的影响。结果表明,溶胶浓度为0.5%、涂层次数为3、热处理温度为100℃时得到的TiO2薄膜具有最好的耐蚀性。     

纳米Ag2S/TiO2异质复合薄膜的制备和光电性能

以异丙醇钛(C12H28O4Ti)为主要原料合成氧化钛(TiO2)前驱体溶胶,并结合230℃水热处理得到TiO2溶胶,利用电流体动力学(EHD)技术在掺氟氧化锡导电(FTO)玻璃基片上镀膜,450℃高温煅烧制备具有多级结构锐钛矿TiO2纳米薄膜.以硝酸银(AgNO3)及硫化钠(Na2S)分别为银源和硫源,采用化学浴沉积...     

多壁碳纳米管负载纳米二氧化钛的制备及其分散性研究

在超声波震荡作用下,采用浓硝酸浸泡,对多壁碳纳米管( MWCNTs)进行纯化;以钛酸四丁酯为前驱体,利用溶胶-凝胶法制备负载纳米二氧化钛的MWCNTs,并研究了不同处理工艺对MWCNTs分散性能的影响.利用TEM,XRD分析分别对MWCNTs的形貌和物相组成进行表征.结果表明:采用浓硝酸浸泡可以有效地纯化MWCNTs;利用溶胶-凝胶法可以在MWCNTs表面负载纳米TiO2;纯化、负载纳米TiO2和超声波震荡可以提高MWCNTs在乙醇中的分散性.     

铁掺杂TiO2纳米粉的制备、表征及其光催化活性

以钛酸丁酯为前驱体,硝酸铁为杂质添加剂,利用溶胶-凝胶法制备了掺铁TiO2纳米粉.以苯酚水溶液的光催化降解反应为探针,评价了掺铁TiO2的光催化性能.借助X射线衍射分析(XRD)、荧光光谱(FS)、热重-差热分析(TG-DTA)等手段对掺铁TiO2催化剂进行了表征.结果表明,掺杂浓度和焙烧温度对掺铁TiO2纳米粉的光催化降解活性有很大影响.掺铁0.5%、煅烧温度为400 ℃的催化剂表现出最佳的光催化活性,在苯酚的降解中催化效率比未掺杂TiO2纳米粉约提高了1倍;并初步探讨了荧光强度对光催化活性的影响.     

TiO_2和活性炭纤维复合物光催化降解亚甲基蓝

以粘胶基活性炭纤维(VACF)为基体,钛酸丁酯为前驱体,通过溶胶-凝胶浸渍涂覆法将二氧化钛(TiO2)负载于粘胶基活性炭纤维上,制备活性炭纤维负载的TiO2光催化复合物,通过控制活性炭纤维在溶胶中的浸泡时间,制得不同TiO2负载量的复合物。采用扫描电子显微镜(SEM)表征了制备材料的形态结构,以质量浓度为20mg/L的亚甲基蓝溶液为目标降解物,测试了材料在紫外线光照下的催化性能。结果表明:紫外光直接照射对亚甲基蓝基本无降解作用,对活性炭纤维原样有一定作用;随着TiO2负载量的增加,复合物的吸附性能得到提高,对亚甲基蓝的降解作用也得到增强。     

氮掺杂TiO2光催化杀菌性能的研究

以廉价的TiOSO4为原料,通过水解法制备正钛酸前驱体,然后向正钛酸前驱体中加入尿素作为氮源,经煅烧制备氮掺杂纳米TiO2,采用X射线衍射、紫外-可见吸收光谱和扫描电镜等方法对制备的样品进行了表征,研究了不同N/Ti配比、煅烧温度、TiO2浓度、细菌浓度对光催化杀菌的影响.结果表明,制备的样品均为锐钛晶型,氮掺杂使TiO2在可见光区的光吸收明显增强;煅烧温度和N/Ti配比对光催化杀菌效果影响显著;当TiO2的质量浓度为1.5g/L时杀菌效果最好;当细菌浓度低于106细胞/mL时,氮掺杂TiO2的杀菌率可达90%以上.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

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.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

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

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

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...     

Flow calorimeter for enthalpy increment measurements on condensed gases

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.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

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.……     

Roman iron and steel: A review

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.     

Optimum-Simulation von Ernteprozessen

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.     

A study of centrifugal cast high boron high speed steel

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.     

Brainstorming for ISO Strategy 2016-2020

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