钛基体上氧化铝膜层的耐高温和耐腐蚀性能研究

钛材高温氧化严重,为了提高其使用性能,采用溶胶-凝胶法在钛合金材料表面制备了耐腐蚀性能优良的三氧化二铝膜层.通过700 ℃下氧化增重的测量、扫描电镜对涂层高温氧化前后表面形貌的观察以及其在3.5%NaCl溶液中的阳极极化曲线测量表明,带涂层的试样在700 ℃、20 h的增重仅有0.028 0 mg/cm2,无涂层的试样增重为1.005 2 mg/cm2;带涂层的试样ΔE=1 203.5 mV,裸露钛合金试样的ΔE=154.6 mV.在钛合金材料表面制备的氧化铝溶胶-凝胶膜层具有提高钛合金材料表面抗高温氧化和耐腐蚀性能的特点.     

低温一步制备氧化石墨烯及微波还原研究

以天然鳞片石墨为原料,通过低温一步氧化制备氧化石墨烯,经微波热还原得到低缺陷的还原氧化石墨烯。讨论了低温氧化过程中氧化剂用量、氧化时间对氧化石墨烯层间距、氧化程度的影响。结果表明:在高锰酸钾与天然鳞片石墨的质量比为1∶3,氧化温度为0℃,氧化时间为48h的条件下,制备出碳氧原子比为1.98、高C—O结构、低缺陷结构( I D∶ I G=0.63)的氧化石墨烯,避免了Hummers制备过程中由于CO 2的形成导致六元环断裂以及碳原子的缺失而使得氧化石墨烯的缺陷增加;经微波热还原后,得到的还原氧化石墨烯的两点平均缺陷距离 L D=12nm,缺陷密度 n D=2.21×10 11 cm -2 , I D∶ I G仅为0.85(Γ G=32.1cm -1 ),制备出低缺陷的还原氧化石墨烯。     

木质素磺酸钠掺杂聚(3,4-乙撑二氧噻吩)水分散性复合材料的制备和表征

在水性介质中,以可再生资源木质素磺酸钠作为新型掺杂剂和软模板,采用化学氧化聚合法制备了在水中稳定分散的聚(3,4-乙撑二氧噻吩)—木质素磺酸复合材料。采用红外光谱、紫外-可见吸收光谱、TGA、SEM以及电导率仪对其性能进行了相关测试和表征。结果表明:所制备的材料呈现管状或纤维状的微观构型,当木质素磺酸钠与3,4-乙撑二氧噻吩单体的质量比为1.5∶1时,所制备的复合材料室温电导率可达1.15·10-3 S/cm,并具有热稳定性和分散稳定性好等优点,该材料在抗静电涂层和生物医用导电高分子领域具有潜在的应用前景。     

甲醇中萘溶液标准物质的研制

以色谱纯甲醇和高纯物质萘为原料,采用重量-容量法准确制备特性量值为1.00×10-4 g/mL的甲醇中萘溶液标准物质.研制的标准物质通过了均匀性检验和稳定性考察,并对定值结果进行了不确定度评定.该溶液标准物质已被批准为国家二级标准物质(编号GBW(E)130395),相对扩展不确定度为3％(k=2),可用于液相色谱仪的检定.     

咪唑类碱性离子液体催化大豆油制备生物柴油

合成了3种以咪唑为阴离子的新型强碱性离子液体([Bmim] Im,ChIm,[N4222]Im),并以其作为催化剂进行了大豆油酯交换制备生物柴油的研究.结果表明:这3种新型强碱性离子液体具有较高的催化活性.选取[Bmim]Im离子液体对反应条件进行了考察,在反应温度60℃,醇(甲醇)油摩尔比6∶1,催化剂用量(以大豆油质量分数为基准)3％,反应时间3h的工艺条件下,生物柴油的收率可达94.1％.[Bmim]Im可重复利用6次且稳定性性能较好,具有良好的重复利用性.     

新型薄层氮化碳/氧化石墨烯复合材料的制备及在锌-空气电池中的应用

本研究通过简单的自上而下的方法成功改进了氮化碳材料,并通过引入氧化石墨烯制备出薄层的石墨烯复合材料(CoOx/PCN/RGO),该复合材料在氧还原反应和氧析出反应中表现出良好的双功能电催化活性(ΔE=0.95 V)和稳定性.CoOx/PCN/RGO复合物作为锌-空气电池的阴极材料时,显示出优于Pt/C+Ir/C的充放电性能.CoOx/PCN/RGO复合材料的优异催化性能主要归因于其薄层结构、大的比表面积和充分暴露的活性中心.     

纤维素/木质素微球抗紫外薄膜制备与性能研究

随着包装工业的快速发展和人类社会对环保要求的提高,功能性且可生物降解的包装膜材料越来越受到人们的重视.然而,目前市场上的可降解包装膜材料由于成本较高、力学性能差以及耐水性低而限制了其发展.采用自组装方法制备木质素微球,并将其沉积在纤维素膜表面,制备出一种新型纤维素基抗紫外薄膜材料.通过扫描电子显微镜(SEM)、红外光谱(FTIR)和激光共聚焦电子显微镜对薄膜的表面性能进行研究.利用抗张实验和紫外透光率测试对纤维素基功能薄膜的力学性能和抗紫外性能进行表征.结果表明:自沉积木质素微球在纤维素膜表面分布均匀,尺寸为1～2μm;纤维素薄膜疏水改性后有助于木质素微球的沉积,且沉积量随着木质素质量浓度的增加而增大.由于木质素微球的引入,纤维素复合膜的抗张强度比对照样增加22％,同时其对UVB屏蔽效果可达94％.     

木质素基树脂的制备及其对重金属离子的吸附性能

以木质素磺酸钠为原料,利用反相悬浮聚合技术,成功制备木质素基树脂.研究了木质素基树脂的制备工艺及其对重金属离子Pb2+、Cd2+的吸附性能.结果表明,优化的聚合条件为:液体石蜡与反应水溶液的相比为3:1、分散剂占有机相百分含量为2%、温度为90℃、盐酸浓度为3mol/L、甲醛占木质素磺酸钠百分含量为9%、聚合时间为2h.30℃时,所制备的树脂对Pb2+、Cd2+的饱和吸附量分别达到33.6523mg/g和30.12mg/g.所制备的木质素基树脂有大量羟基和磺酸基等含氧基团存在,非常有利于它对重金属离子的吸附.木质素基树脂的比表面积为0.0963m2/g,孔容为0.002389cm3/g,平均孔径为99.2208nm,表明该树脂具有大孔树脂的结构特点.     

钴铁双金属氢氧化物纳米片的制备及其在高电流下的电催化全解水性能

采用一步水热法,通过在高传导泡沫镍(Nickel foam,NF)表面原位生长制备的钴铁双金属氢氧化物纳米片,被证明是一种在高电流下具有良好稳定性的高效双功能全解水电催化剂.在1 mol/L KOH电解液中,当电流密度为100 mA/cm2、200 mA/cm2、250 mA/cm2时,其析氧过电位分别为216 mV、269 mV和284 mV,塔菲尔斜率仅为49.79 mV/dec;当电流密度为10 mA/cm2、50 mA/cm2、100 mA/cm2和200 mA/cm2时,其析氢过电位分别为137 mV、221 mV、256 mV和297 mV,塔菲尔斜率为113.15 mV/dec.全水解只需要一个超低的电压(1.532 V),就可以获得200 mA/cm2的电流.在200 mA/cm2运行20 h后,电流密度仅下降8.86％;维持200 mA/cm2运行20 h,电压仅上浮2.12％.可见,所制备的钴铁双金属氢氧化物纳米片具有高效、稳定的电催化性能.     

木质素基模板炭的制备及电化学性能

以造纸黑液碱木质素为碳前驱体、硅藻土为模板,采用高温烧结和水热活化制备有序排列的硅藻土模板炭.利用X射线衍射(XRD)、拉曼光谱(RS)、扫描电子显微镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)等对其进行分析与表征,并通过测试恒电流充放电、循环伏安法、交流阻抗、循环寿命等来研究其电化学性能.结果表明:所制备的模板炭生长在硅藻土的孔隙中,呈现出中空管状结构.当木质素/硅藻土质量比为1:1,将其于900℃烧结2 h后,再通过180℃水热反应活化10 h,制备的模板炭电极材料具有较好的电化学性能.在电流密度为0.5 A/g时,该材料的质量比电容可达207.65 F/g;而在电流密度为2 A/g时,经过5000次循环充放电后,其比电容保持率仍达到95.4％,这表明所制备的木质素基模板炭材料具有良好的电化学性能.     

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.……     

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...     

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.     

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.     

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