生物炭及其复合材料活化过硫酸盐研究进展EI北大核心

以硫酸根自由基(SO_(4)^(-)·)为基础的高级氧化工艺被公认为是降解有机废水的有效方法之一。作为一种经济、易得的含碳材料,生物炭已逐渐应用于高级氧化领域。生物炭及其复合材料活化过硫酸盐已成为一种较有前景的有机污染物降解体系。本文分析了用于过硫酸盐活化的不同典型生物炭基催化剂最新研究进展,包括原始生物炭、过渡金属负载生物炭、非金属掺杂生物炭、金属与非金属共掺杂生物炭等。总结了其合成方法和理化性质,并分别讨论了生物炭基催化剂对过硫酸盐的活化性能与机理,以及该体系对有机污染物的降解机理。最后根据现有研究进展,分别从不同生物质来源、金属非金属共同改性生物炭技术以及降解过程中生态毒性动态变化等角度,针对降解机制探索、潜在催化剂开发和实际催化系统应用等方面,对生物炭及其复合材料进行了相关讨论并提出建议。     

生物炭及其复合材料活化过硫酸盐研究进展

以硫酸根自由基(SO^-₄·)为基础的高级氧化工艺被公认为是降解有机废水的有效方法之一。作为一种经济、易得的含碳材料，生物炭已逐渐应用于高级氧化领域。生物炭及其复合材料活化过硫酸盐已成为一种较有前景的有机污染物降解体系。本文分析了用于过硫酸盐活化的不同典型生物炭基催化剂最新研究进展，包括原始生物炭、过渡金属负载生物炭、非金属掺杂生物炭、金属与非金属共掺杂生物炭等。总结了其合成方法和理化性质，并分别讨论了生物炭基催化剂对过硫酸盐的活化性能与机理，以及该体系对有机污染物的降解机理。最后根据现有研究进展，分别从不同生物质来源、金属非金属共同改性生物炭技术以及降解过程中生态毒性动态变化等角度，针对降解机制探索、潜在催化剂开发和实际催化系统应用等方面，对生物炭及其复合材料进行了相关讨论并提出建议。     

层状双金属氢氧化物活化过硫酸盐降解有机污染物研究进展

近代工业的快速发展造成大量难降解的新型有机污染物进入水体，亟需经济、高效的难降解有机污染物污染控制和削减技术。近年来，基于硫酸根自由基(SO₄^·–)的高级氧化技术（SR-AOPs）具有强氧化性、宽pH耐受性以及方便操作性等优势而备受关注。不同种类的金属氧/硫化物、碳基材料、金属-非金属复合材料以及有机金属材料等被用来活化过硫酸盐产生活性氧，从而实现对有机污染物的氧化降解和进一步矿化。其中，层状双金属氢氧化物（Layered double hydroxides, LDHs）因其独特的层状结构优势、阴离子可交换性和客体分子可调节性，在活化过硫酸盐方面表现出优良的反应活性和催化优势。本论文从催化剂类型、催化性能与机制以及降解体系影响因素等方面，综述了LDHs及其复合材料作为非均相催化剂活化过硫酸盐的研究现状，并对催化体系持续改进以及未来发展提出相关展望。     

石墨烯基复合材料降解有机污染物研究进展

石墨烯与金属化合物复合材料因具有优异的光催化性能成为新型光催化材料的研究热点之一。介绍了石墨烯的结构及特性,综述了石墨烯与钛、铋、锌、铁等化合物复合材料的制备方法及其在光催化降解有机污染物方面的研究进展,展望了石墨烯基复合材料在光催化领域的研究与发展前景。     

氮掺杂生物炭吸附降解有机污染物的研究进展

生物炭是生物质热解和碳化后产生的高含碳物质。氮掺杂生物炭改善了生物炭的性能，使其在吸附降解有机污染物等方面的应用前景更为可观，引起了学者的广泛关注。而氮掺杂生物炭对有机污染物的吸附降解性能受多种因素影响，如生物炭的制备条件及其性质等。详细讨论了生物质原料和掺杂方式等因素对氮掺杂生物炭性质的影响，总结了氮掺杂生物炭吸附和降解有机污染物的影响因素及机理，并提出了氮掺杂生物炭的未来研究方向。     

高级氧化技术在医疗废水处理中的应用

在医疗废水中存在较多难降解的类有机污染物,容易对环境造成持久性污染。高级氧化技术具有众多优点,在水体污染物降解以及医疗废水处理方面有较多的应用。基于此,该文对高级氧化技术的机理及其活化方法进行分析研究,进而为提高高级氧化技术在处理医疗废水方面的应用,提供参考。     

普鲁士蓝/生物炭材料的制备及其氨氮吸附机理

以氮、磷污染物导致的水体富营养化问题在我国普遍存在。本研究将普鲁士蓝与改性生物炭相结合,得到普鲁士蓝/生物炭复合材料。通过多种表征手段研究了复合材料的形貌及结构并通过模拟废水测试了其吸附性能。结果表明,复合材料在pH8时达到最佳吸附效果,氨氮去除率在95%以上,最大吸附量为24.4mg/g,比未改性生物碳提高101.3%。对复合材料吸附机理的研究表明,复合材料通过普鲁士蓝对氨氮的配位作用对多组分污水中氨氮实现了选择性吸附。此外,复合材料在外加H₂O₂溶液的条件下可形成芬顿氧化体系,能实现同步催化降解有机污染物和促进氨氮的吸附,因此有望在多组分富营养化污水治理中投入实际应用。     

介孔炭材料及介孔炭/氧化硅复合材料对大分子有机污染物的吸附

介孔炭材料与活性炭相比具有较大的孔体积和孔径,高的比表面积以及规则的孔道结构,而介孔炭/氧化硅复合材料兼顾了活性炭与介孔材料的优点,因此在吸附大分子有机污染物方面有很好的应用前景。笔者综述了近年来介孔炭,负载/修饰后的介孔炭,介孔炭/氧化硅复合材料的制备和最新研究进展。在制备方面,根据其制备机理的不同可分为硬模板法和软模板法,制备出有序的介孔炭与介孔炭/氧化硅复合材料。在应用方面,重点介绍了介孔炭材料和介孔炭/氧化硅复合材料对大分子有机污染物的吸附性能。进而对介孔炭/氧化硅复合材料在吸附方面的应用进行了展望。     

纳米TiO2光催化降解水中有机污染物的研究与发展

光催化降解水中有机污染物是一项新兴的颇有发展前任的废水处理技术,纳米Ｔｉｏ２因其活性高,稳定性好而在该领域广泛被用作光催化剂。本文系统介绍了纳米ＴｉＯ２的制备,光催化降解水中有机污染物的机理,动力学规律及其研究现状和发展方向。     

海藻基CDs-Cu-TiO2复合材料的制备及其光催化性能

光催化降解技术能够高效去除废水中的有机污染物, 具有广阔的应用前景。本研究以海藻为碳源, 采用微波水热法制备海藻基碳量子点(CDs), 并进一步合成CDs-Cu-TiO₂复合材料作为可见光催化剂用于污染物降解。结果表明, 复合材料中CDs、Cu²⁺与TiO₂紧密结合在一起, 可见光区吸收明显增强, 荧光发射效率降低。CDs与Cu²⁺的引入产生协同效应, 使复合材料的禁带宽度降低到2.35 eV, 并有效抑制了电子-空穴的复合。以罗丹明B为污染物模型的光催化性能实验显示, 海藻基CDs-Cu-TiO₂复合材料在可见光照射下降解RhB的一级反应速率常数能够达到纯TiO₂纳米颗粒的6.4倍, 150 min降解率接近100%, 是TiO₂纳米颗粒的2倍。     

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.