罗丹明B敏化锐钛矿型TiO2的低温制备及性能

采用溶胶-凝胶法在低温(60～80℃)下制备得到罗丹明B染料敏化的锐钛矿型TiO2粉体.利用X射线衍射、红外光谱、荧光光谱、紫外-可见光吸收光谱、漫反射光谱对光催化剂的晶相结构、吸收光谱特征进行了表征,结果表明:罗丹明B与TiO2发生了相互作用,罗丹明B敏化的TiO2在可见光区域的吸收增强.光催化氧化实验表明,经罗丹明B敏化的锐钛矿型TiO2粉体,在普通日光灯下对甲基橙具有良好的光催化活性.     

N掺杂TiO2光催化剂的制备及性能研究

采用溶胶-凝胶法制备锐钛矿型N掺杂TiO2粉体,通过X射线衍射光谱(XRD)、红外光谱(FT-IR)、紫外/可见光漫反射吸收光谱(UV-vis)对粉体的性能进行表征.结果表明,N掺杂使TiO2粉体的晶粒细化,禁带宽度减小,光谱吸收阈值波长向可见光区红移至550nm左右.光催化降解甲基橙的实验表明,N-TiO2粉体在普通日光灯下对甲基橙的降解率明显优于纯TiO2粉体.     

FePc/TiO2纳米光催化剂的制备与光催化性能研究

采用sol-gel方法,制备了FePc/TiO2纳米光催化剂,采用XRD、UV-vis、荧光光谱对光催化剂进行了表征,以罗丹明B为降解目标物,研究了FePc/TiO2在紫外光照射(中心波长364nm)下的光催化活性.FePc敏化TiO2提高了光催化活性,其可能机理是,在sol-gel制备及后处理过程中,TiO2与FePc之间形成了较强相互作用,即某种较强的化学键合,可以促进能量与电子的转移,促使光生电子与空穴的有效分离,提高了光催化量子效率.     

CeO2掺杂TiO2光催化剂的性能研究

采用液相合成法制备CeO2掺杂TiO2光催化粉体,利用X射线衍射仪、紫外-可见分光光度计、FT-IR傅里叶变换红外光谱仪等对粉体的晶相组成、光谱吸收性能进行了表征,结果表明,掺杂后的TiO2经800℃热处理后仍呈锐钛矿型;CeO2/TiO2吸收光谱的阈值波长发生红移,但Ce掺杂浓度的增大对粉体的可见光吸收影响不大.光催化降解甲醛的结果表明,粉体在普通日光灯下对甲醛气体的降解率明显优于P25.     

TiO_2纳米粉体的溶胶-凝胶工艺制备和光催化活性表征

通过溶胶 -凝胶工艺制备了锐钛矿型TiO2 纳米粉体 ,TiO2 粉体由 40～ 80nm的球形颗粒组成。XPS研究表明 :TiO2 纳米粉体中主要含有Ti和O元素 ,未发现其它杂质元素 ,O/Ti的原子比为 2 .14,其中含有一定量的羟基 (-OH)。甲基橙水溶液的光催化降解实验表明 :溶胶 -凝胶工艺制备的锐钛矿型TiO2 纳米粉体的光催化活性明显高于普通TiO2 粉体。     

TiO_2纳米粉体的溶胶-凝胶工艺制备和光催化活性表征

通过溶胶 -凝胶工艺制备了锐钛矿型TiO2 纳米粉体 ,TiO2 粉体由 40～ 80nm的球形颗粒组成。XPS研究表明 :TiO2 纳米粉体中主要含有Ti和O元素 ,未发现其它杂质元素 ,O/Ti的原子比为 2 .14,其中含有一定量的羟基 (-OH)。甲基橙水溶液的光催化降解实验表明 :溶胶 -凝胶工艺制备的锐钛矿型TiO2 纳米粉体的光催化活性明显高于普通TiO2 粉体。     

pH值及含水量对自蔓燃制备TiO_2光催化性能的影响

为了考察pH值及含水量对溶胶-凝胶自蔓燃法制备TiO2粉体光催化性能的影响,以TiO(NO3)2为前驱体,在原料、燃烧剂和燃烧助剂的物质的量比为n(TiCl4)∶n(C6H8O7)∶n(NH4NO3)=1∶1∶3,以及煅烧温度550℃不变的情况下,改变溶胶pH值和含水量,制备TiO2粉体,利用X射线衍射和扫描电镜进行结构表征,通过降解亚甲基蓝验证光催化性能。结果表明:该条件下制备的TiO2粉体具有松散、多孔的特性,晶型为锐钛矿。在pH值为7、含水质量分数为50%的条件下,TiO2的光催化活性最高。     

钒掺杂对TiO_2晶型转变的影响

以钛酸四丁酯为原料,利用溶胶-凝胶法制备了纯TiO2粉体和钒(V)掺杂的TiO2粉体,并利用TG-DSC,XRD,SEM等方法对样品进行了表征。结果表明:V的掺杂促进了TiO2粒子由锐钛矿型向金红石型的转变,并使晶型转变温度范围变窄;TiO2晶粒的尺寸随焙烧温度的升高逐渐长大,随掺杂量的增加逐渐减小。TiO2粉体粒子在锐钛矿型状态下,颗粒分散均匀,并且无明显团聚现象。因此,V掺杂TiO2具有良好的光催化活性。     

不同介质中水热合成纳米TiO2粉体及其光催化性能研究

以钛酸四丁酯为原料,采用水热法分别以蒸馏水、有机小分子化合物(正丁醇、丙二酸和乙二胺水溶液)和无机酸(HNO3、H2SO4和HCl)为介质合成了TiO2纳米粉体.通过XRD和TEM对所得TiO2粉体进行了表征,研究不同介质对所得TiO2粉体的晶相组成、颗粒尺寸及形貌的影响.结果表明:以蒸馏水为介质时所得锐钛矿TiO2的颗粒尺寸分布不均匀;有机化合物抑制锐钛矿型TiO2各向异性生长趋势的能力为:正丁醇＞丙二酸＞乙二胺;相同实验条件下,HCl、H2SO4及HNO3体系中分别获得金红石、锐钛矿及锐钛矿和金红石混晶TiO2.光催化降解甲基橙的研究表明,锐钛矿和金红石混晶TiO2的光催化活性要高于纯锐钛矿结构;纯金红石型TiO2的光催化活性最差.     

纳米二氧化钛的晶型转变及光催化性能研究

采用溶胶-凝胶法制得稳定的TiO2透明溶胶．凝胶经焙烧制备了纳米TiO2粉体,利用FT-IR、XRD和原子力显微镜(AFM)技术对其进行了结构和形貌表征,考察了其对水杨酸的光催化活性。研究结果表明,醇胺不同的加入量,对TiO2从锐钛矿转变为金红石型的晶相转变温度(600～800℃)有很大影响．FT-IR谱的423cm^-1处吸收峰为金红石型TiO2的特征Ti-O键振动峰,采用310nm的紫外光波长照射时锐钛矿型TiO2粉体具有较高的光催化活性。     

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