二氧化钛/硅胶的液相沉积法制备与性能研究

采用硫酸钛水解沉积法在硅胶载体上包覆纳米二氧化钛,研究载体表面负载二氧化钛的结构、表面形态及其光催化性能。实验发现,包覆在硅胶表面的二氧化钛大小约为400nm,且分布均匀,二氧化钛粒子为锐钛矿相,并且在样品的紫外-可见漫反射谱图中没有观测到蓝移现象,以偶氮染料甲基橙作为降解对象研究所制备样品的光催化性能。     

低温等离子体射流制备二氧化钛薄膜及其光催化活性的研究

利用大气压低温等离子体射流技术,以空气为放电气体,四氯化钛为钛源,在玻璃载玻片基底上制备了二氧化钛薄膜。利用扫描电镜及椭圆偏振仪分析测量了薄膜的表面形貌与沉积速率。利用紫外光照射硬脂酸分解速率评价所制备薄膜的光催化活性,结果显示在同一放电输入功率及气体流量条件下,四氯化钛前驱体引入位置距射流枪枪口越近,所制备的二氧化钛薄膜光催化性能越高。在同一反应位置时,放电输入功率的增加有助于提高二氧化钛薄膜的光催化活性。     

铝合金表面制备二氧化钛薄膜及其光催化活性研究

分别以阳极氧化处理的6061铝合金和纯铝为载体,用液相沉积的方法在载体上制备了二氧化钛薄膜.结果表明,在6061铝合金上的TiO2纳米薄膜呈现带有孔洞的竹节状结构,而纯铝基片上的TiO2纳米薄膜具有良好的一维贯通结构.这主要是在AAO模板制备过程中,由于铝合金中的合金元素Mg被氧化,其产生的氧化物体积比Al2O3的体积小所致.在铝合金表面的TiO2薄膜光催化性能优于纯铝表面的TiO2薄膜.铝合金表面制备的TiO2薄膜因其特殊的带孔洞的竹节状结构,使其比表面积比纯铝上的TiO2薄膜大,因此其光降解甲基蓝效果更好.TiO2对甲基蓝的光催化降解符合一级反应动力学公式,在0.1 mol/L的氟钛酸铵溶液中沉积得到的TiO2薄膜光催化性能最好,表观反应速率为k=0.00444/min.     

铒掺杂二氧化钛制备及其光催化性能研究

通过水热合成法制备了二氧化钛和稀土饵离子掺杂二氧化钛光催化剂,并通过X射线衍射仪、紫外-可见分光光度计等测试手段对产物结构和性能进行了表征,研究了不同二氧化钛质量浓度、饵离子掺杂浓度对次甲基蓝(MB)光催化性能的影响.结果表明,所制备的二氧化钛的晶型为锐钛矿型;饵离子掺杂的二氧化钛对比纯二氧化钛的光催化性能有显著提高.当二氧化钛质量浓度为3g/L时,对MB的降解效果最好;通过研究饵离子掺杂对MB光催化动力学模型,表明饵离子掺杂有较高的一级反应速率Kapp,且饵离子最佳掺杂量为5%.     

铝沉积还原制备蓝色二氧化钛

在光催化研究中, 提高光催化剂的催化效率, 降低催化剂成本吸引了广泛的研究兴趣。本研究通过铝沉积还原方法制备出表面铝原子修饰的蓝色二氧化钛。该蓝色二氧化钛具有一种独特的核壳结构, 纳米颗粒内部为结晶核, 外部为含有大量氧空位和一定量沉积铝原子的非晶层。在模拟太阳光照射下, 该蓝色二氧化钛表现出优异的光催化污染物降解和光电化学性能。在高真空条件下, 当蒸发的金属铝原子沉积在二氧化钛纳米颗粒上时, 可以进一步将Ti⁴⁺还原成Ti³⁺, 使得催化剂表面含有大量的氧空位等表面缺陷。此外, 适量的铝沉积在催化剂表面成为光生载流子阱, 促进光生载流子的分离和输运, 从而使得样品光催化活性增强。当沉积适量Al时, 样品TiO₂-Al_0.36表现出最为优异的光催化污染物降解性能, 在8 min内就可将甲基橙溶液完全降解, 且其光电流(1.47 mA·cm^-2)是本征二氧化钛(0.17 mA·cm^-2)的8倍以上, 展现出优异的光电化学性能。     

TiO2/硅灰复合材料的制备及其光催化性能的研究

以钛酸四丁酯为主要原料,无水乙醇做溶剂,冰醋酸做抑制剂,盐酸做负催化剂,采用溶胶凝胶法制备了负载量不同的TiO2/硅灰复合纳米粒子。以甲基橙的降解为模型反应,评价了试样的光催化活性,并采用红外光谱、X射线衍射、扫描电镜等测试手段对其进行了性能表征。结果表明,以硅灰为载体,负载型二氧化钛催化剂较未负载二氧化钛催化剂有更高的光催化活性。     

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%.     

晶粒尺寸可控的纳米二氧化钛的制备

采用微乳法和溶胶-凝胶法相结合的方法制备纳米二氧化钛,通过改变制备参数可以将纳米二氧化钛的晶粒尺寸控制在6~30 nm之间。采用X射线衍射、透射电镜等表征手段,对不同的制备条件与晶粒尺寸的关系进行研究。通过在可见光下对亚甲基蓝水溶液的降解测试其光催化活性。结果表明:补充结论纳米二氧化钛具有良好的光催化性能。     

TiCl_4自生晶种水解法制备纳米二氧化钛

采用TiCl4自生晶种水解法制备纳米二氧化钛,研究了反应物的添加方式和浓度对二氧化钛粉体形貌和晶相的影响,制备了粒径20～30nm,分散性好的球状纳米二氧化钛。用亚甲基蓝的光催化降解研究了最佳条件下所制备的二氧化钛粉体的光催化活性。结果表明:该二氧化钛粉体对亚甲基蓝的光催化降解在100min内可达95%以上,具有较高的光催化活性。     

双子表面活性剂为模板纳米二氧化钛的制备及光催化活性

以脱氢松香为原料,通过化学合成的方法制备出一种新颖的双子表面活性剂,采用FT-IR及1 HNMR对其结构进行确证;以酞酸四正丁酯（TNB）为起始原料,通过加入自制的双子表面活性剂,采用水热合成法制备了平均粒径为8.81nm的锐钛矿型纳米二氧化钛颗粒;利用FT-IR、TEM、XRD对纳米二氧化钛进行表征;以紫外光为光源,罗丹明B（RhB）为模型污染物考察了纳米二氧化钛的光催化活性,结果表明其催化活性优于未加表面活性剂制备的纳米二氧化钛,且在紫外光下反应3h,RhB的降解率为99.7%,基本完全降解。     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

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.