ZrO_2-AC电极材料制备工艺的确定及性能表征

采用浸渍-焙烧法对活性炭(AC)进行载锆改性,选取浸渍浓度、浸渍时间和焙烧温度为影响因子,以比电容为评价指标,通过单因素和正交试验确定ZrO_2-AC电极材料的最佳制备工艺,利用BET、SEM、EDS及FT-IR对载锆前后活性炭材料进行性能表征。结果表明:ZrO_2改性活性炭的最佳工艺参数为浸渍浓度1.5mol/L,浸渍时间16h,焙烧温度500℃;活性炭负载ZrO_2后比电容增加了72.6%,比表面积降低了12.75%;ZrO_2-AC电极材料的表面及孔道出现絮状和颗粒状的ZrO_2,Zr元素的质量分数为16.8%,表面形成Zr—O键的含氧官能团。活性炭负载ZrO_2后加速了电极双电层的形成,提高了电极材料的电化学性能,可作为电吸附除盐的电极材料。     

柑橘皮中孔活性炭的制备及性能表征

以柑橘皮为原料,以氯化锌为活化剂,采用一步炭化法制备了中孔活性炭.研究了浸渍比、炭化温度及保温时间对孔结构的影响,通过BET、D-R方程、BJH方程及Kelvin理论表征了活性炭的孔结构,采用红外光谱分析样品的表面官能团,透射电镜观察微观形貌.柑橘皮中孔活性炭的适宜制备条件为:活化剂漫渍比3:1,炭化温度550℃,保温时间1h;所得活性炭中孔容积1.438cm3/g,中孔率占68.5%,BET比表面积为1476m2/g;该活性炭孔径分布集中,平均孔径3.88nm.利用中孔活性炭吸附垃圾渗滤液生化尾水,UV254值和TOC去除率分别为94.7%、66.4%.3DEEM证明该活性炭对DOM中的类富里酸具有良好的吸附性能,紫外区类和可见区类富里酸荧光强度分别降低49.1%、81.6%.     

Cu(Ⅰ)/AC(HZSM)吸附剂的制备及变压吸附CO的性能研究

选择活性炭(AC)或分子筛(HZSM-5)为吸附剂载体,采用等体积浸渍法制备Cu(I)/AC(HZSM)吸附剂.利用比表面积(BET)及H2程序升温还原(H2-TPR)表征手段.结合固定床评价了装置,研究了载体类型、预处理方法以及还原温度对吸附剂性能的影响.结果表明,以活性炭为载体时吸附性能优于分子筛为载体时的吸附性能;水洗处理降低了吸附剂的吸附能力;吸附剂原位活化还原温度过低不利于Cu2+→Cu+的还原,350℃时吸附剂的吸附性能最好.     

ZnCl2活化茄子秸秆制备活性炭及表征

以茄子秸秆为原料、ZnCl2为活化剂制备活性炭。通过正交实验方法确定了制备活性炭的最佳工艺条件,采用低温氮气吸附、BET、Langmuir和BJH理论对其孔结构进行了表征,利用红外光谱分析样品的表面官能团,扫描电镜观察表面形貌。结果表明以茄杆活性炭的最佳工艺条件:浸渍比为2,浸渍时间为8h,活化温度为550℃,活化时间为60min,所得的活性炭的碘吸附值为1270.06mg/g,亚甲基蓝吸附值为17.4mL/g;BET和Langmuir比表面积分别为1649.615和1851.649m2/g,吸附总孔容为0.488cm3/g,吸附平均孔径为2.241nm。     

碱金属盐对黏胶基活性炭纤维表面大孔形成的影响

以黏胶纤维为原料,用碱金属盐和路易斯酸对其进行预处理,经化学活化与水蒸气活化,制得了大孔型活性炭纤维(ACF).采用扫描电镜(SEM)和BET等温吸附法分别对ACF表面微观结构和材料的吸附性能进行了对比表征,着重研究了碱金属盐浓度与浸渍时间的关联.结果表明:通过控制添加碱金属盐的浓度和浸渍时间,可以控制活性炭纤维表面的孔径大小及其分布,制备出表面既富含大孔(孔径>50nm)也有丰富微孔(孔径<2nm)的新型复合孔型ACF,该材料具有较高的比表面积.     

表面氧化改性制备活性炭电极材料及其电化学性能研究

以商用活性炭为原料,采用20%硝酸液相氧化处理后,制备了硝酸改性活性炭。采用低温N_2吸附法表征了活性炭的孔结构性质,采用FTIR、Boehm滴定法进行了表面性质表征,测定、比较了商用活性炭和不同温度条件下的硝酸改性活性炭为原料所制备电极的循环伏安、恒定电流充放电、交流阻抗等电化学性能,探讨了硝酸改性活性炭电极的电容产生机理。实验表明,经硝酸氧化处理后,活性炭的比表面积和孔容略微增加,平均孔径稍增大,含氧官能团数量有所增加。由于氧化处理后活性炭材料赝电容的增加,相比商用活性炭电极的比电容量89.61F·g~(-1),硝酸改性活性炭电极比电容量增大到106.56 F·g~(-1),并表现出较好的功率特性、容量特性和较小的阻抗,同时具有大电流放电的特性。     

盐酸预处理对ACF结构及其电化学性能的影响

采用活性炭纤维(ACF)毡作为原材料,对比评价在煮沸、振荡、超声三种条件下的HCl预处理对其结构及电化学性能的影响。通过BET、SEM、FTIR研究ACF结构的变化,并以灰分和碘值考察ACF的吸附性能以及采用CV曲线分析ACF电极材料的电化学性能变化。结果表明,除HCl超声外,其他预处理都使活性炭纤维的形状和尺寸变得相对规整;经HCl煮沸和HCl振荡处理后的ACF比表面积分别增大34.87%和32.73%,其碘吸附值分别增大41.8%和42.1%,HCl振荡的比电容最高可达62F/g;而HCl超声处理却造成ACF表面刻蚀,其碘值和比表面积均较原样降低。综合比较各种方法的预处理效果如下:HCl振荡HCl煮沸HCl超声;HCl振荡处理效果最好,且使ACF表面酸性含氧基团增多,更有利于对无机盐离子的吸附。     

醋酸乙烯载体竹活性炭的磷酸法制备与性能表征

以竹节为原料,采用磷酸法制备醋酸乙烯催化剂载体活性炭。采用N2吸附等温线、Boehm滴定法、热重-质谱仪(TG-MS)、傅里叶红外光谱仪(FT-IR)和扫描电子显微镜(SEM),对磷酸法竹活性炭和水蒸气法椰壳活性炭的吸附性能、比表面积、孔结构、表面官能团和微观结构进行比较。结果表明,竹活性炭的醋酸吸附性能、比表面积和孔隙结构与椰壳活性炭相近;且竹活性炭具有更丰富的—COO-、—OH-和PO、P—O—C和POOH等表面官能团。磷酸法竹活性炭的制备有望为醋酸乙烯催化剂载体活性炭的生产提供新工艺,实现对水蒸气法制备椰壳活性炭的替代。     

炭表面改性对负载型TiO_2/活性炭复合光催化剂性能的影响

采用HNO3、H2O2和O3对商品活性炭进行表面改性处理,考察了改性处理对活性炭表面基团、负载TiO2以及所形成的TiO2/活性炭复合光催化剂性能的影响。利用傅里叶红外光谱(IR)、X射线光电子能谱(XPS)、扫描电镜(SEM)及氮气吸附等手段对材料进行了表征。结果表明,3种改性方法均可有效提高活性炭载体表面的含氧官能团数量,但是对活性炭的比表面积和孔容影响不大;H2O2和O3对活性炭载体改性后可以提高对钛前驱体的吸附性能,HNO3改性有利于TiO2颗粒在活性炭表面的分散。使用改性后的活性炭作为载体制备的TiO2/活性炭光催化降解甲基橙的性能均高于未改性的TiO2/活性炭催化剂,其中以HNO3改性后的TiO2/活性炭活性最高。     

磷酸法活化煤焦油渣制备活性炭研究

研究了以陕西煤焦油渣作为原料,用磷酸作为活化剂,在400～1000℃的条件下经一步炭活化法制备活性炭。研究了炭活化温度、时间、料剂比对煤焦油渣制备活性炭吸附性能及孔结构的影响。实验结果表明炭活化温度、炭活化时间主要影响活性炭产品的得率,高温和长时间会导致更多的碳损失;活性炭的吸附性能及孔结构主要受炭活化温度和料剂比影响。最佳活化工艺条件为850℃、3h、1∶3。通过其活性炭表面孔径分布及表面官能团含量变化表征,用磷酸浸泡煤焦油渣制备活性炭有利于大、中孔结构的产生,其最佳活化条件下孔径分布约在20～100nm。     

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.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.……     

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.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.