原位沉淀-焙烧法制备NiO/P-CNT复合材料及其电容性质

以聚吡咯衍生的碳纳米管作为载体,通过原位沉淀-焙烧相结合,合成了新型的氧化镍/聚吡咯衍生碳纳米管(NiO/P-CNT)复合材料。采用粉末X射线衍射、热重、能谱、扫描电镜、透射电镜、循环伏安以及恒流充放电测试对样品进行表征和分析。结果表明,须状氧化镍均匀的负载在聚吡咯衍生的碳管表面,构成了具有三维网络结构的复合物。基于这种特殊结构的优势,该复合物在电流密度为2A/g下的比电容为382F/g,NiO在复合物中电容贡献为441F/g,而NiO的比电容为351F/g。经过400圈充放电后,复合物的比电容保持在90%以上,而NiO的容量保持率为82.6%。因此,该复合电极材料较NiO具有更高的比电容和更好的循环特性。     

原位沉淀-焙烧法制备NiO/P-CNT复合材料及其电容性质

以聚吡咯衍生的碳纳米管作为载体,通过原位沉淀-焙烧相结合,合成了新型的氧化镍/聚吡咯衍生碳纳米管(NiO/P-CNT)复合材料。采用粉末X射线衍射、热重、能谱、扫描电镜、透射电镜、循环伏安以及恒流充放电测试对样品进行表征和分析。结果表明,须状NiO均匀地负载在聚吡咯衍生的碳管表面,构成了具有三维网络结构的复合物。基于这种特殊结构的优势,该复合物在电流密度为2A/g下的比电容为382F/g,NiO在复合物中电容贡献为441F/g,而NiO的比电容为351F/g。经过400圈充放电后,复合物的比电容保持在90%以上,而NiO的容量保持率为82.6%。因此,该复合电极材料较NiO具有更高的比电容和更好的循环特性。     

NiO电极材料的溶胶凝胶法合成及其超级电容的性能

用溶胶凝胶法和简单热处理合成的NiO电极材料,其最大比电容达到744 F/g。使用X射线粉末衍射、扫描电子显微镜、投射电子显微镜和N2气吸附解吸仪等手段表征了NiO材料的微观结构和聚集形态。将氧化镍和活性炭分别作为正负极组装非对称性电容器,用循环伏安法和恒流充放电法研究其在2 mol/L的KOH电解液中的超级电容性能。这种非对称性电容器表现出良好的能量密度、功率密度和循环稳定性,循环1000次后其循环稳定性能为初始比电容值的84.3%。     

氧化镍三维纳米电极的制备及其超级电容性能研究

以阳极氧化法制备的TiO2纳米管阵列为基底,利用水热法在上面成功制备出NiO三维纳米电极。通过晶体粉末衍射仪(XRD)、场发射扫描电镜(SEM)、X射线光电子能谱(XPS)分析了其物相组成、表面形貌及元素价态,同时也分析了NiO直接在TiO2纳米管阵列上三维生长的过程。超级电容性能结果表明:NiO三维纳米电极在充放电电流密度在2.5A/g下,比电容为918F/g的容量,循环2000圈之后容量保持在93%,是较为理想的超级电容器用清洁储能材料。TiO2纳米管阵列显著提高了NiO与基底接触的牢固程度,克服了粉末材料制备电极的繁琐过程,较大地提高了电极材料的循环性能。     

石墨烯/氧化镍复合材料的微波法制备及电化学性能研究

采用微波法快速制备了石墨烯/氧化镍(MWGO/NiO)复合材料,利用扫描电子显微镜、X射线衍射仪和傅里叶变换红外光谱仪对其结构和形貌进行了表征。通过循环伏安法和恒电流充放电测试了MWGO/NiO复合材料的电化学性能,考察了微波功率、微波时间、投料比对复合材料性能的影响。结果表明:氧化石墨烯与硝酸镍质量比为5∶4、微波功率为1000W、微波时间为2min时,制备的复合材料电化学性能最好;在充放电电流密度为1A/g及KOH电解液浓度为6mol/L时,复合材料的最大比电容为360.5F/g。     

三维石墨烯-氧化镍纳米晶复合膜的电容性能

本文首先采用高温化学气相沉积技术(CVD)在泡沫镍模板上生长三维石墨烯(3DG),然后利用化学浴沉积在石墨烯表面沉积碱式镍沉淀,氩气退火后得吸附氧化镍纳米片晶的石墨烯复合膜(3DG/NiO)。X-射线衍射(XRD)、拉曼(Raman)光谱、场发射扫描电子显微镜(FESEM)表征表明:泡沫镍表面生长了致密的三维石墨烯膜,层与层之间呈现明显的堆垛方式;石墨烯膜表面吸附了大量的NiO纳米片状晶体,相邻的纳米晶相互连接形成多孔结构。循环伏安(CV)曲线研究表明:3DG/NiO膜可作为兼具双电层电容和赝电容性能的复合型电极材料。充放电曲线研究表明:3DG/NiO电极的稳定充、放电比电容处于350~400F·g-1之间,300次循环后仅衰减1.12%,库仑效率保持在95%以上。     

NiO的热分解制备及其电化学电容性质

以亚氨基二乙酸(IDA)为配位剂与Ni2+配位,经300℃热处理得到NiO.XRD、FT-IR、SEM以及TG研究表明,生成的配合物在热处理时首先生成单质,后随温度升高逐渐转化为纳米颗粒与纳米片结合的氧化物;循环伏安、恒电流充放电及循环寿命电化学测试表明,所得NiO电极在6 mol/L KOH电解液中具有较好的电化学电容特性和循环稳定性,1 A/g电流密度下的单电极比容量可达355.8 F/g.     

纳米片状NiO的合成及电容性质

采用沉淀法在500℃下草酸溶液中合成了NiO纳米片。以扫描电子显微镜(SEM)、X射线衍射仪(XRD)、循环伏安曲线和充放电曲线等表征了所得NiO的形态、晶体结构和电化学性质。结果表明,所得到的NiO纳米片长度为100～150nm,宽度为30～50nm。NiO的纯度高,晶体结构为六方相。并且纳米片的形态和晶格常数随合成温度的改变而变化。由于纳米片形貌大大增加了表面氧化镍的比率,所得NiO纳米片具有较好的电容性质,循环伏安曲线包含两对较强的氧化还原峰,比电容量为157.89F/g。     

NiO/TiO_2纳米复合电极的制备及电化学性能研究

金属氧化物理论上具有较高的比电容,是赝电容超级电容器的主要电极材料,不同的沉积方法将直接影响到其电化学性能。首先采用阳极氧化法制备高度有序的TiO_2纳米管阵列作为基底,分别采用化学沉积法和电化学沉积法(差分脉冲伏安法)沉积NiO,测试并比较所沉积NiO的电化学性能。电子扫描显微镜表征发现化学沉积的NiO颗粒较大未能均匀沉积,电化学沉积法沉积形成的NiO颗粒较小且均匀附着在纳米管中。恒流充放电结果显示电化学沉积法制备的复合电极获得了60mF/cm~2的比电容,可以用作电化学超级电容器的电极材料。     

有机体系中聚苯胺电化学性能研究

有机体系中，采用循环伏安法（CV）在铂片表面电聚合制备聚苯胺，并通过循环伏安、恒流充放电测试了聚苯胺的电化学特性，结果表明：聚苯胺电极的循环伏安曲线呈现矩形特征，恒流充放电的电压和时间关系为线性关系。说明该电极具有典型的电容行为，其比电容高达320．8F／g。CV循环500圈后比电容基本没有变化，电极的循环寿命较高。     

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.     

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.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to