电弧法制备洋葱状富勒烯的工艺研究

运用纳米Bi2O3微粒作催化剂，在电弧放电条件下，进行了纳米洋葱状富勒烯大量合成的研究。并用透射电镜对产物的形貌、结构进行了观察与分析。结果表明：纳米洋葱状富勒烯的石墨化程度很高，且直径均匀(约为25nm)，结构较完善；同时伴有单核纳米洋葱状富勒烯向多核纳米洋葱状富勒烯的转变。为洋葱状富勒烯的宏量制备提供了有利线索。     

纳米金属微粒催化制备的洋葱状富勒烯的结构表征

采用金属Cu，Al做粒／石墨混合材料．用直流电弧放电方法制备了洋葱状富勒烯。对两种产物进行了XRD、SEM、HRTEM和Raman结构表征。结果表明：两种纳米金属微粒均可催化得到洋葱状富勒烯；所得产物中有单纯洋葱状富勒烯和内包纳米金属微粒洋葱状富勒烯，且石墨化程度都很高；纳米金属微粒尺寸大小不同决定洋葱状富勒烯的直径分布不均匀，从而造成其拉曼谱峰相对于石墨特征峰1582cm^-1发生了频移；用汽-液-固(VLS)生长模型描述了洋葱状富勒烯生长机理，解释了汽态碳原子通过在液态催化剂中扩散和析出，逐渐长大成形的现象。     

水下放电制备内包金属洋葱状富勒烯的研究

以二茂铁和纳米Ni粒子为催化剂,在水下放电条件下,制备了内包金属洋葱状富勒烯(Onion-like Fullerenes:OLFs),利用高分辨透射电镜(HRTEM)和X射线衍射(XRD)对所得产物进行了表征.结果表明:二茂铁和纳米Ni粒子均可催化得到内包金属洋葱状富勒烯,内包Fe洋葱状富勒烯直径分布在5～50nm之间,内包Ni洋葱状富勒烯直径分布在10～35nm之间.     

催化剂种类对纳米洋葱状富勒烯形成的影响

研究了相同电弧放电条件下,不同催化剂(Fe、Al)掺杂对洋葱状富勒烯形成的影响.用高分辨透射电子显微镜(HRTEM)和X-射线衍射(XRD)对产物进行了观察与表征.结果表明,Fe作催化剂形成的洋葱状富勒烯产量和质量都优于Al作催化剂的情况,Fe的催化活性较Al的高,是制备洋葱状富勒烯的一种更加有效的催化剂.     

Fe/洋葱状富勒烯的化学修饰及润滑性研究EI北大核心

采用化学气相沉积(CVD)法制备了内包金属Fe/洋葱状富勒烯,利用高分辨透射电镜(HETRM)、X-射线衍射(XRD)和傅立叶红外(FT-IR)等对产物的结构和形貌进行了表征;运用硬脂酸对Fe/洋葱状富勒进行化学修饰;着重讨论硬脂酸修饰后Fe/洋葱状富勒烯作为润滑油添加剂的分散性和稳定性。结果表明所制备的Fe/洋葱状富勒烯颗粒均匀,通过酯化反应Fe/洋葱状富勒烯能够被硬脂酸包覆,显著提高了Fe/洋葱状富勒烯在润滑油中的分散性和稳定性。在MRS-10A型四球摩擦试验机上考察了Fe/洋葱状富勒烯作为机油添加剂的润滑性能。     

纳米洋葱状富勒烯的研究进展及动向

评述了纳米洋葱状富勒烯的研究发展过程和动向，论述了该物质的各种制备方法及其工艺，并对各种制备工艺进行了分析和探讨性研究，在此基础上比较论述了每种方法的优缺点，展望了纳米洋葱状富勒烯基础研究，宏量制备和应用研究的发展趋向。     

Fe@洋葱状富勒烯的拉曼特征

采用化学气相沉积方法制备了Fe@洋葱状富勒烯并采用高分辨透射电镜（HRTEM）、拉曼（Raman）分析对其进行了表征。结果表明：产物粒径稳定在50nm左右，拉曼特征峰相对于HOPG发生了软化，这是由于其特殊的弯曲层状结构造成。     

洋葱状富勒烯的制备与提纯

采用CVD法制备了洋葱状富勒烯(OLFs),研究了不同工艺条件对OLFs形成的影响,并通过硝酸回流法对得到的粗产品进行了提纯处理.研究结果表明,在相同的反应体系中,采用乙炔作碳源,氩气和氢气的混合气体作载气,制得的OLFs的纯度较高;硝酸处理可有效去除粗产品中碳纳米管、无定形炭和金属催化剂颗粒等杂质,使得OLFs的整体纯度得到提高.     

水下电弧放电法制备洋葱状富勒烯

探索了纯石墨电极在水中放电制备洋葱状富勒烯（Onion-like fullerenes，OLFs）的过程和工艺。用高分辨透射电镜（High resolution transmission electron microscope。HRTEM）对生成的OLFs进行了形貌、结构的观察与表征。分析结果表明制得的OLFs具有各种不同形状的内核。石墨化程度很高，直径分布在5nm～40nm范围内。在一定范围内随着电流强度的增大OLFs的产量和产率都有不同程度的提高。     

催化化学气相沉积过程中硫元素引发的炭形貌衍变

以甲苯为碳源,二茂铁为催化剂,噻吩为生长促进剂,通过化学气相沉积方法得到了多分叉结构的炭.借助SEM、XRD和EDX考察了硫元素对产物的形貌和微观结构的影响.结果表明,当甲苯中的噻吩体积分数在0.01%～1%变化时,产物形貌由树状逐渐衍变为分支状.树状炭南较长而笔直的多分叉炭纤维构成,而分支状炭则由较短且弯曲的炭纤维构成.XRD结果表明硫元素对产物的微观结构没有明显的影响.     

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.