Preparation of free–standing transparent titania nanotube array membranes

在由乙二醇、水、氟化铵组成的电解液中添加钼酸钠调节阳极附近的离子浓度, 制备出厚度大约为10微米的透明二氧化钛纳米管阵列薄膜. 所得二氧化钛是无定型结构, 在120℃水热处理可以将其转化成锐钛矿结构, 并保持薄膜的结构完整性. 该薄膜的透射率与其表面结构和晶体结构有关. 这种透明二氧化钛纳米管阵列薄膜可望应用于染料敏化太阳能电池.     

二氧化钛纳米管阵列的应用研究进展

二氧化钛纳米管阵列具有独特的结构、良好的化学惰性、更大的比表面积、纳米管与基底结合牢固等优点,其应用非常广泛.综述了二氧化钛纳米管阵列在太阳能电池、传感器、光解水制氢、光催化和环境分析方面的应用研究进展,并提出了二氧化钛纳米管阵列的应用发展趋势及展望.     

低温水热合成钛酸钡纳米管阵列薄膜及性能研究

以二氧化钛纳米管阵列为模版,用水热法合成了钛酸钡纳米管阵列薄膜.讨论了水热温度、水热时间、碱的浓度对其生长形貌的影响.用X射线衍射仪、扫描电子显微镜表征了其晶体结构及微观形貌;用热重-差示扫描量热仪测定了材料的热学性能;用宽频介电阻抗谱仪测试了样品的介电性能.结果表明,在低至100℃水热温度下反应6h即可制得单一相的钛...     

阳极氧化法制备二氧化钛纳米管阵列的形貌

采用阳极氧化法,以NH4F-乙二醇-水溶液为电解质,在钛片上制备了TiO2纳米管阵列,并研究了电解电压和电极距离对TiO2多孔薄膜形貌的影响。结果表明,通过优化电解电压,可以调控二氧化钛纳米管阵列的内径在20～145nm之间;通过调节两电极间的间距,在金属钛片上制备了完整的二氧化钛纳米孔阵列。并采用有限元模拟二氧化钛层中的电流密度分布,探讨了二氧化钛纳米管阵列和纳米孔阵列的形成。     

TiO2纳米管阵列薄膜的水热晶化

首先在KF和乙二醇的混合溶液中利用阳极氧化技术在钛基底表面制得了一层排列整齐、形貌均一的TiO₂纳米管阵列薄膜,然后将制得的薄膜进行水热处理,通过扫描电子显微镜、X射线衍射仪等表征手段研究了水热处理温度和时间对TiO₂纳米管阵列薄膜表面形貌、结晶度以及管状结构的影响。结果表明:水热处理即使在较短的时间内（如3 h）也可在较低温度下（如210℃）使TiO₂纳米管阵列薄膜由无定形转变为锐钛矿型结构;提高水热处理温度或延长水热处理时间均可提高薄膜的结晶度,但同时纳米管管壁结晶度增加会使管内径变小甚至堵塞,从而破坏管状结构。     

CeO2修饰的透明TiO2纳米管电极的电致变色器件

采用电化学沉积法在阳极氧化制备的TiO2纳米管阵列管壁上沉积一层CeO2纳米颗粒,再将CeO2修饰的透明TiO2纳米管阵列薄膜对电极与聚三甲基噻吩变色电极组装成透过型电致变色器件.实验结果表明:CeO2修饰的TiO2纳米管阵列薄膜仍保持良好的光透过性,其电荷存储能力比纯TiO2纳米管电极提高了30%.经CeO2修饰的TiO2纳米管改善了器件的性能,与对电极为单一TiO2纳米管阵列的器件相比,其对比度仍保持在38%左右,其褪色时间由1.3 s缩短为0.8 s.电致变色器件快速响应得益于纳米管与纳米颗粒组成的复合结构的高比表面积和快速的电荷传输过程.     

氧化钛纳米管阵列的制备、性能及应用

二氧化钛由于具有化学稳定性高、禁带宽、无毒、来源丰富及价格低廉等优势,在环境治理、新能源开发以及生物组织工程研究等领域具有广泛的应用前景。其中二氧化钛的微观形貌控制是影响其性能的重要因素之一,采用阳极氧化法制备得到的二氧化钛纳米管阵列具有高度有序的定向排列结构,活性位点多,比表面积大,在染料敏化太阳能电池、贵金属催化剂载体以及种植体表面改性等领域具有巨大的应用前景。对二氧化钛纳米管阵列的制备工艺以及二氧化钛纳米管阵列在染料敏化太阳能电池、贵金属催化剂载体以及种植体表面改性的应用等方面进行介绍,并结合本课题组以及国内外同行的研究成果,对二氧化钛纳米管阵列未来在上述应用领域的发展前景进行展望。     

宁波材料所在二氧化钛纳米管阵列结构研究中取得进展

中国科学院宁波材料技术与工程研究所表面事业部科研人员采用电化学方法在钛基体表面原位构筑二氧化钛纳米管阵列结构用于气体净化和污水的深度处理。该技术通过制备纳米管阵列结构,提高二氧化钛的比表面积,显著提高催化降解效率。利用非金属元素掺杂,实现了二氧化钛结构可见光下对污水和气体的高效降解和净化作用,对缓解雾霾有一定效果。     

不同阳极氧化条件下TiO_2纳米管阵列的制备及表征

分别在三种不同的电解液中,以钛为基体采用阳极氧化的方法制备了TiO2纳米管阵列薄膜,用SEM观察纳米管阵列薄膜的形貌、测量纳米管管径大小;用XRD、拉曼光谱检测TiO2纳米管阵列薄膜热处理前后的晶型.结果表明:不同的电解液体系和氧化电压下得到的纳米管形貌各不相同.在0.24wt%HF水溶液中得到的TiO2纳米管排列整齐,管径为110nm;在0.5wt%NaF+2.7wt%Na2SO4水溶液和0.88wt%NH4F的丙三醇-水(体积比1:1)混合溶液中得到的纳米管排列不规整,管径为100nm;在0.24wt%HF条件下生成的TiO2纳米管管径与氧化电压成线性关系:d=k×U+b,其中,系数k=5.2nm/V,b=2.2nm,0≤U≤25V.经450℃热处理2h后TiO2纳米管结构由无定形态转变为锐钛矿.     

钴掺杂TiO2纳米管阵列薄膜的制备及其光催化还原性能

用磁控溅射法在ITO玻璃基底上制备Ti-Co合金薄膜,对其阳极氧化处理制备出钴掺杂TiO₂纳米管阵列薄膜,研究了钴掺杂对纳米管阵列薄膜的形貌、结构、吸收光谱以及光催化还原性能的影响。结果表明：钴掺杂TiO₂纳米管阵列薄膜为锐钛矿相,管状阵列的管径均一、排列规整。钴掺杂使薄膜形成(001)择优取向。随着钴掺杂量的提高,薄膜吸收可见光的能力提高。钴含量(原子分数)为0.19%的薄膜光催化性能最优,可见光照150 min后对Cr(VI)的还原率可达98.4%。     

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.