Fe掺杂钛基SnO2/Sb电催化电极的制备及表征

为了改进钛基SnO2/Sb电极的电催化性能,采用高温热氧化法制备了Fe掺杂钛基SnO2/Sb 电极.采用SEM、EDX以及XRD等方法对所制备电极的表面形貌、元素组成及结构进行分析,并以苯酚为目标有机物,研究了所制备电极对有机污染物的电催化降解能力.结果表明,适量Fe的掺杂有利于晶粒细化和导电性的提高;但过量Fe的掺杂可能导致SnO2晶格的混乱程度增大,甚至使晶格破坏,从而使电极性能降低;掺杂0.5?的SnO2/Sb电极对苯酚的降解效果优于未掺杂Fe的电极;电解3 h后,苯酚去除率和化学需氧量(COD)去除率分别达到100.0%和92.0%.     

ACF阳极氧化法去除水中腐殖酸的研究

以活性炭纤维毡为阳极,不锈钢片为阴极,采用电化学氧化法处理了含腐殖酸的水溶液.结果显示,该方法可有效去除水中的腐殖酸,对于初始浓度为50mg/L的腐殖酸溶液,在适宜条件下电解120min后,腐殖酸和COD去除率可分别高达93.81%和92.60%.实验考察了溶液pH值、电流密度、支持电解质浓度、腐殖酸的初始浓度和阳极材...     

活性炭纤维电极法处理含酚废水的研究

以活性炭纤维作为阳极,不锈钢板为阴极,采用电化学氧化法对模拟的含酚废水进行了处理.结果表明,该方法可以有效分解除去水中的苯酚,苯酚和COD的去除率均能达到95%以上,其最佳的操作条件为:pH值为3、进水苯酚浓度为500mg/L、电流密度为26mA/cm2、Na2SO4浓度为15g/L.同时,通过对比不同电极材料的降解效果,证明了具高比表面积的活性炭纤维作为电极材料,能充分将其导电、吸附、催化及稳定性能有效地结合起来,实现高效净化,具有良好的应用前景.     

双膜三室同槽电解金属锰和微粒电解二氧化锰的控制因素

采用双膜三室电解法同槽电解金属锰和微粒电解二氧化锰,同时中隔室回收硫酸。分别研究了Mn~(2+)浓度、电流密度、电解温度、阴极(NH_4)_2SO_4浓度、阳极H_2SO_4浓度对电沉积效果的影响。结果表明:在阴极Mn~(2+)浓度40 g/L、初始pH=6.9、(NH_4)_2SO_4浓度110 g/L、电流密度400 A/m~2,阳极Mn~(2+)浓度40 g/L、H_2SO_4浓度2.5 mol/L、电流密度800 A/m~2,极间距90 mm,电解温度45℃,电解时间5 h条件下,阴极电流效率可达77.53%,能耗为6 725.28 kW·h/t,阳极电流效率可达84.87%,能耗为3 883.91 kW·h/t,酸回收率达到63.2%。阴极产品金属锰表面光滑平整,晶粒为块状,呈层状堆积,阳极产物微粒电解二氧化锰颗粒细小,粒径分布均匀,有较规则的晶体形貌。     

基于含油废水处理的电催化膜反应器优化设计及性能研究

以负载纳米TiO2的电催化膜为阳极,辅助电极为阴极,构成电催化膜反应器用于含油废水处理.考察了电极间距、电解质浓度、电流密度、空时速率、pH和温度对电催化膜反应器降解效果即含油废水化学需氧量(COD)去除率的影响.根据单因素实验分析结果,采用响应面法对电极间距、电解质浓度、pH和温度四个参数进行优化,得出最佳参数为:电极间距43.1mm,电解质浓度14.3 g/L,pH=6.3,温度32.5℃.在电流密度0.312mA/cm2,空时速率15.8 h-1的条件下,电催化膜反应器处理200mg/L含油废水COD去除率为97.54％,能耗为0.75 kWh/m3.     

单膜双室同槽电解金属锰联产EMD离子的传输机理研究

针对传统布式隔膜袋电解技术工艺中存在的诸多弊端,本研究提出了单膜双室膜电解工艺,以MnSO4+(NH4)2 SO4为电解液体系,实现在阴极产锰的同时在阳极联产电解二氧化锰,并在阳极室中回收硫酸.通过测定阴阳极室中各离子成分的变化情况,来深入分析电解过程中的离子传输行为,以验证单膜双室同槽电解的技术可行性.实验结果表明:单膜双室电解法能够有效实现同槽电沉积金属锰并联产电解二氧化锰,同时在阳极室中回收硫酸,硫酸浓度可达1.5 mol/L,满足前端锰矿酸浸工艺要求,促进了对资源的高效回收利用.采用TRJAM-10W阴离子交换膜的阴极产锰率和阳极酸回收率最高,分别可达77.0％和64.3％,而采用Ionsep-HC阴离子交换膜的阳极产EMD率最高,为27.3％.TRJAM-10W阴离子交换膜的槽电压最小,为4.43 V,其电能消耗也最低,为5607 kW·h·t-1.     

壳聚糖基粒子电极降解p-NP废水的效果研究

为了提高电解有机废水降解率,增加三维电极的种类,体现有机物作为粒子电极可接枝修饰的优势。以自制壳聚糖为粒子电极,选择钛基锡系电极和石墨分别为阳极和阴极,组成三维电化学反应器,研究三维电极反应器对模拟对硝基苯酚(p-NP)废水进行电催化氧化效果,探讨了电流密度、极板间距、粒子电极填充量等因素对废水处理效果。实验结果表明较佳电解条件为电流密度为0.2A/cm2、极间距为1cm、粒子填充量0.6g/cm3、电解时间100min时,降解率可以达到80%以上。     

电絮凝法预处理苎麻废水实验研究

采用可溶性Fe阳极材料通过电絮凝法预处理苎麻废水。实验研究废水的pH值、电流密度、电解时间、极板间距等因素对废水COD、BOD及色度去除率的影响,并确定最适宜工艺条件:pH=8.5,电流密度Id=6.25A/dm~2,电解时间T=15min,极板间距d=20mm,此时苎麻废水的COD、BOD及色度去除率可分别达到30.02%、23.27%、84.17%。     

Co3O4纳米阵列电催化膜电极及其处理难降解废水耦合产氢性能研究(英文)

传统电化学高级氧化技术存在有机物降解效率不高、能耗大的弊端,并且平板式电极表面存在滞止边界层,严重限制了传质过程.本工作中,我们首先通过水热方法将一维Co₃O₄纳米针状阵列结构原位负载于金属钛膜电极,低压电场下,实现难降解有机物的去除,其中:对于苯酚的去除率可达≥99%,化学需氧量(COD)和总有机碳(TOC)去除率分别为9 9.5%和9 2.5%,电流效率为8 8.7%,能耗仅为0.061 kW h (kg COD)^-1. Co₃O₄纳米针的阵列式膜电极可以提供更多的CoOOH活性位,增强电场强度,而且其穿透式流体模式导致强化对流,可以明显地改善电催化反应过程的传质,因而提高膜电极的催化效率,降低能耗.最后,我们设计了H型电催化膜反应器,耦合阴极的析氢反应,降解有机物的同时制备纯氢,极大地提高了电极和膜反应器的效率.     

生物阳极辅助Ag/RGO/BiVO_4催化膜阴极系统的水处理研究

用水热法合成Ag/RGO/BiVO_4,涂覆在不锈钢网上制备得到膜电极,此膜电极兼具光催化、电催化及过滤、杀菌性能.膜组件形式的阴极与生物阳极构建成由离子交换膜分隔的两室水净化处理和产电系统,该系统在阴极膜过滤出水条件下,模拟连续运行的水处理工艺,净化实际景观水(含有藻类﹑COD和氨氮等污染物).当水力停留时间为12h时,阴极去除COD68%,平均878mg/(m~2·h),氨氮去除68.4%,且经阴极膜组件过滤后的出水较原液明显清澈;阳极室中总氮去除21%,COD去除87.5%.与处理实际景观水相比,系统对单一污染物四环素的去除效率更高(86%).此外,系统最大产电功率和开路电压分别为285.6 mW/m~2,0.361V;阴极光电催化降解四环素的主要活性物种为·O_2~-和h~+;光照下膜电极能够抑制粪大肠杆菌,进一步提高出水品质.     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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 ...