纳米TiO2的制备,表征及光催化性能的研究

采用硬脂酸凝胶（SAG）法制备了TiO2纳米材料,用差热分析,热重分析,X射线衍射对合成过程进行了研究。用X射线光电子能谱（XPS）对其表面状态进行了分行。TiO2纳米材料对甲基橙溶液光催化降解结果表明：催化剂浓度、初始溶液pH值和金属离子对降解效率有较大影响。     

铁掺杂纳米TiO2的制备及其光催化性能研究

采用溶胶-凝胶法制备了掺杂Fe3 的纳米TiO2微粒,采用X光衍射仪对粉体进行了表征.以甲基橙为目标降解物,研究了Fe3 掺杂纳米TiO2光催化性能.结果表明,掺杂适量Fe3 能够提高TiO2的光催化活性,当Fe3 的掺入量为摩尔比0.41%时催化活性最高.以紫外灯为光源,降解初始浓度为20mg·L-1的250mL甲基橙溶液,催化剂0.41%(摩尔分数)Fe3 -TiO2投加量为0.5g时,甲基橙的光催化降解效果最好.     

Fe掺杂ZnO/TiO2光催化性能

采用溶胶-凝胶法制备了Fe掺杂ZnO/TiO2纳米催化剂粉体,利用多种技术手段对样品的组成、形貌、表面化学态、光学性能等进行表征分析,同时通过降解甲基橙溶液来评价样品的光催化性能.研究结果表明,掺杂Fe能稳定ZnO/TiO2的锐钛矿相,细化催化剂颗粒,并且促进光的吸收带隙红移.Fe-ZnO/TiO2的光催化活性相比Ti...     

Ag/TiO_2复合纳米催化剂的制备和表征及其光催化性能研究

以TiCl4,AgNO3为原料,采用水热法制备了Ag/TiO2复合纳米催化剂。采用X-射线衍射仪、透射电镜等对其进行结构表征,得到金红石型均匀掺杂的Ag/TiO2复合纳米颗粒。为了评估Ag/TiO2光催化材料的催化活性,在中性条件下以Ag/TiO2作为光催化剂,进行了在自然光下催化降解甲基橙的实验,实验结果表明:Ag/TiO2复合纳米催化剂对甲基橙的光催化降解具有较好的催化作用。     

TiO_2-Al_2O_3负载型催化剂的制备及其光催化性能

以钛酸四丁酯和氢氧化钠为反应物,采用两步水热法制备TiO2纳米线,并将其原位负载于Al2O3载体上,研究它们对甲基橙的光催化降解性能。结果表明,锐钛矿相TiO2主要呈纳米线和八面体状负载在Al2O3载体上,当TiO2负载质量分数为30%,焙烧温度为400℃,催化剂用量为1.332 0 g/L时,TiO2-Al2O3负载型催化剂光催化降解甲基橙的性能最佳,光照5 h后,甲基橙在紫外和太阳光下的降解率分别达到58.9%和55.6%。相同实验条件下,TiO2-Al2O3负载型催化剂对甲基橙的降解率比单纯TiO2提高了35.1%。     

TiO2膜/硅胶复合微球的制备及光催化性能

采用硅胶微球为载体,以TiO2溶胶为涂膜液,制备TiO2膜/硅胶复合微球,用XRD,FT-IR和显微镜等对催化剂的物相、形貌行了表征,并考察其对甲基橙溶液的光催化降解性能.结果表明:TiO2膜和硅胶微球之间存在化学键合作用,涂膜5层微球粒径为0.5～3mm,呈白色,水溶液中透明,是理想的光催化材料.其光催化性能随涂膜层数和催化剂用量的增加而增大,涂膜的5层微球甲基橙降解率可达85%.     

TiO2负载ZnO纳米棒的制备及其光催化性能

采用水热法制备ZnO纳米棒,将TiO2溶胶高速旋涂在ZnO纳米棒的表面,得到TiO2/ZnO复合半导体。通过扫描电子显微镜(SEM)、X射线衍射(XRD)及UV-Vis漫反射等研究样品的表面形貌、晶型结构及光学特性。结果表明:375℃高温焙烧后,TiO2生长成颗粒状,均匀负载在ZnO纳米棒的表面,样品对紫外-可见光的吸收增强。以甲基橙溶液为模拟废水在紫外光辐照下的降解率来评价样品的光催化性能,结果显示,两种半导体复合以后,对光的利用率提高,对甲基橙模拟废水的降解率高于单一半导体。     

TiO_2柱撑蒙脱土的制备及其光催化性能的研究

采用TiCl4在 HCl中的水解制备TiO2柱撑蒙脱土(TiO2-PILM)纳米光催化材料,通过X射线衍射和红外光谱对其进行了表征.考察了甲基橙的初始浓度、甲基橙溶液、pH值对光催化降解效果的影响.结果表明,TiO2-PILM具有大的晶面间距,TiO2-PILM 对甲基橙有较好的光催化活性,吸附动力学数据很好地符合Lagergren二级速率方程,在甲基橙初始浓度为10mg/L、投样量为0.02g、在酸性或碱性条件时,TiO2-PILM对甲基橙的降解率较高.     

膨胀石墨负载纳米TiO2光催化剂的制备及对甲基橙溶液的吸附与光降解

以钛酸丁酯为钛源,膨胀石墨为载体,采用溶胶-凝胶法成功地制备了膨胀石墨(EG)负载TiO2光催化剂(TEG),采用X射线衍射分析(XRD)、扫描电镜(SEM)、比表面积等分析技术对样品进行表征,以甲基橙为目标降解物,考察了热处理温度、负载次数、目标降解物浓度等不同条件下催化剂的光催化性能.结果表明,氧化钛以纳米颗粒的形式附着在膨胀石墨薄片表面,具有疏松多孔蠕虫状结构的膨胀石墨为氧化钛提供高浓度的三维降解环境,负载2次在500℃下经过3h热处理得到的催化剂在紫外光激发下对甲基橙溶液表现出较高的光催化活性.     

光还原法制备纳米Ag/ZnO及其光催化性能研究

采用光还原法制备了Ag/ZnO光催化剂,并运用紫外-可见光谱、X射线衍射、扫描电子显微镜和透射电子显微镜对催化剂进行表征。以甲基橙为标志物,探究了催化剂的投加量和甲基橙的初始浓度对光催化反应性能的影响。结果表明:Ag~+成功的进入了ZnO晶格中,取代了部分Zn~(2+)。光催化降解反应表明,Ag/ZnO都能够提高光催化效率,当催化剂用量为1.2g/L,光照30min,可以使0.01g/L的甲基橙溶液降解率达到92.259%。     

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.……     

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.……     

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     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to