银在活性炭纤维上的吸附及分布

采用水蒸气、氯化锌或磷酸活化等方法，通过控制不同的活化时间，制备了若干系列的沥青基活性炭纤维，研究了这些活性炭纤维对银离子的还原特性及金属银颗粒在活性炭纤维表面的分布形态。结果显示，纤维表面的金属银颗粒即有微米级粒子，也有纳米级粒子。随制备方法及溶液中银离子的初始浓度不同，还原吸附在纤维表面上的银离子的粒径不同。活性炭纤维的微孔丰富，石墨化程度低，还原吸附的银颗粒相对较细；石墨化程度高，表面化学反应性强，则还原吸附的银颗粒相对较粗。因此，通过调整纤维的制备方法及溶液的银离子浓度，可控制还原吸附到纤维表面上的银粒子基本为纳米级粒子。     

氯化锌活化法制备木质活性炭研究

采用氯化锌活化法在不同操作条件下制备木质活性炭产品,通过实验测定相应的活性炭得率及活性炭的碘值、亚甲基蓝吸附值和苯酚吸附值.分析研究了氯化锌活化法制备活性炭工艺过程中各种操作参数如浸渍比、活化时间和活化温度对活性炭的得率、活性炭碘值、亚甲基蓝吸附值和苯酚吸附值的影响.实验结果表明,浸渍比是氯化锌活化法制备活性炭的最重要的影响因素.综合考虑活性炭的得率和吸附性能受活化操作参数的影响规律,探讨了氯化锌活化法制备木质活性炭的最优操作参数.在实验范围内,选择氯化锌活化法制备木质活性炭的浸渍比100%,活化温度500℃左右和活化时间60～90min比较适宜.     

氯化锌活化法制备笋壳基活性炭的工艺研究

以笋壳为原料,采用氯化锌活化法制备活性炭,通过正交试验研究了氯化锌与笋壳质量比、氯化锌溶液浓度、活化温度、活化时间等因素对笋壳基活性炭的活化收率、碘吸附值和亚甲基蓝吸附值的影响。研究表明,活化温度对活性炭性能的影响最显著;氯化锌活化法制备笋壳基活性炭的最佳条件为:m(氯化锌)/m(笋壳)=2:1,氯化锌溶液浓度为5%,活化温度为600℃,活化时间为90min。采用氮气吸附-脱附法对最佳条件下制备的活性炭进行表征,结果表明,该条件下制备的活性炭为中孔型活性炭。     

几类载银活性炭纤维抗菌活性的比较

利用水蒸汽活化和化学活化方法，制备了各种原料基活性炭纤维，并利用活性炭纤维的氧化还原特性，在其上负载金属银。研究并比较了这些载银活性炭纤维对大肠杆菌的杀灭作用。结果表明，原料基、活化方法、载银量、纤维的比表面积等因素均对材料的抗菌性能有一定的影响。磷酸活化的活性炭纤维表现出强的抗菌杀菌能力；载银量和比表面积越大，其灭菌能力越强；在适当载银量时，磷酸活化活性炭纤维可在短时间内将高浓度细菌基本杀灭。     

孔有效利用的活性炭基非对称电极膜/电容脱盐系统（英文）

采用活性炭纤维为原料制备出膜/电容脱盐系统,提纯含氯化钠的水。OG系列活性炭纤维作为电极的活性材料,其比表面积和孔分布不同而呈现不同的活化程度。将这些材料用于膜/电容脱盐系统,评价了他们对钠离子或氯离子的脱盐性能。膜/电容实验在不同操作电位窗口、含盐溶液的进料速率和浓度下进行。OG系列活性炭纤维对每种离子的脱盐效率和电吸附量来评价膜/电容性能。结果表明,BET比表面积是确保高性能的必要因素。另外,炭材料最上端的浅孔有助于活性炭纤维比表面积的充分利用。OG7A样品的孔结构适合于钠离子吸附,OG10A和OG15A适于大量孔吸附氯离子。因此,非对称电极排列施加于吸附离子的尺寸,应考虑炭材料比表面积和孔面积的有效利用,以得到高性能的膜/电容脱盐系统。     

氢气还原法制备Pt/MoOx/C及其对氧还原的电催化性能

用氢气在高温下还原吸附到碳载体上的钼酸铵和氟铂酸,制备出Pt/MoOx/C金属-氧化物复合型催化剂.考察了Pt/MoOx/C催化剂的电化学性能,经旋转圆盘电极测试表明在低电位区Pt/MoOx/C对含甲醇溶液中的氧还原的催化活性高于Pt/C.     

兰炭基中孔活性炭的制备及性能表征

以兰炭粉为原料,水蒸汽为活化剂,采用物理活化法制备中孔活性炭。分别讨论了活化温度、活化时间、水蒸汽质量流量对活性炭碘吸附值的影响,并采用正交实验对工艺条件进行了优化。利用全自动物理吸附仪对活性炭的比表面积和孔结构进行表征。结果表明:随着活化温度的升高、活化时间的延长和水蒸汽流量的增大,活性炭的碘吸附值均呈现先升高后下降的变化规律。正交实验结果表明,水蒸汽活化兰炭粉的适宜条件为:活化温度900℃,活化时间60min,水蒸汽流量1.25g/min。此条件下制得的活性炭具有多级孔的特征,而且以中孔为主,其碘吸附值为924.45mg/g,比表面积为818.52m2/g。     

KOH活化制备活性碳纤维的研究

本文探讨了ＫＯＨ活化制备活性碳纤维的方法。实验表明，通过在３５０℃以上半碳化天然纤维，再浸泡ＫＯＨ，然后于８５０℃热处理９０分钟，可以制备出高得率和较高比表面积的活性碳纤维。与水蒸汽活化相比，ＫＯＨ活化的纤维，微晶尺寸较小，灰分少，对贵金属离子Ａｕ３＋和Ａｇ＋的吸附量较高。还原吸附在此种ＡＣＦ上的Ａｕ和Ａｇ颗粒粒径可分别小于６００和３００ｎｍ。     

制备工艺对球状活性炭的影响研究

以大孔吸附树脂为原料,通过溶胀、磺化、炭化、活化成功制备出树脂基球状活性炭,研究了溶胀、磺化、活化温度、活化时间、水蒸汽流量对球形活性炭性能的影响。结果表明,经溶胀处理的树脂球磺化更充分;磺化后树脂球炭化收率显著提高。此外,随着活化温度的升高、活化时间的延长、水蒸汽流量的增加,球形活性炭的收率不断降低,CCl4吸附值先增后减。最佳的活化条件(850℃,0.6mL/min的水蒸汽流量活化3h)下,球状活性炭收率达到20%,CCl4吸附值可达2000mg/g。     

不同浸渍方式对氯化锌活化竹纤维活性炭理化结构和性能的影响

为探究浸渍工艺对活性炭理化性质及性能的影响,以脱除木质素的竹纤维为原料,氯化锌为活化剂,通过真空浸渍、常温搅拌浸渍、物理混合浸渍3种不同的方式浸渍竹纤维,采用化学活化法制备竹纤维基活性炭。通过比表面积及孔径分析仪、傅里叶变换红外光谱仪、X射线衍射仪等对活性炭的孔隙结构、化学结构和晶体结构进行表征,并探讨不同浸渍方式制备的活性炭对亚甲基蓝的吸附能力及电化学性能。结果表明：常温搅拌浸渍制备的活性炭比表面积最大,为2096.981m²/g,物理混合浸渍制备的活性炭比表面积最小,为1788.566m²/g;常温搅拌浸渍制备的活性炭微孔最多,真空浸渍制备的活性炭中孔最多;竹纤维活化后纤维素及半纤维素基本分解,不同浸渍方式制备的活性炭官能团并无显著差异;活化后纤维晶型遭到破坏形成无序炭结构,3种浸渍方式制备的活性炭均具有部分石墨和无序石墨的特征。电化学性能测试表明：3种活性炭均表现出明显的双电层电容特性及可逆性;不同电流密度条件下搅拌浸渍制备的活性炭比电容均最高,电流密度为0.2A/g时比电容达到257F/g;真空浸渍制备的活性炭电荷转移电阻更低,物理混...     

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 ...