二茂铁有机磁体/陶瓷磁性复合材料的缩波功能及应用

用二茂铁有机磁体与陶瓷(Al2O3、TiO2、BaTiO3及微波陶瓷SrTiO3·Bi2O3·3TiO2)(简称OPM/SAT)粉末制成4种未见报道并有良好缩波功能的OPM/SAT磁性复合材料,研究了它们的组成与电磁参数(μ′,ε′),电磁损耗(μ",ε")及缩波性能的关系,结果表明,其缩波因子较传统的介质材料大许多倍,在高频、微波下OPM/SAT缩波材料可使微带天线的几何尺寸缩小40%,而带宽为介质天线的3倍,因此,这种新颖的有机磁性缩波材料在理论和实用上有重要的价值.     

高分子磁体/ TiO2复合缩波材料的电磁性能

研究了在100 MHz～1800 MHz 的高频、微波下, 高分子磁体/ TiO₂( 简称OPM/ TiO₂ ) 复合缩波材料的电磁参数变化。研究表明: 丙烯酸改性的OPM/ TiO₂ 复合缩波材料有效地提高其介电常数, 降低介电损耗和磁损耗,而60Co-r 辐照的OPM/ TiO₂ 材料却显著地提高其磁导率及介电常数, 但材料的磁损耗和介电损耗基本不变, 因此,OPM/ TiO₂ 作为一种用于缩小电子器件及天线几何尺寸的复合缩波材料, 对高频, 微波通信、宇航和计算机有重要的理论和应用价值。      

Ta添加对(Fe_(0.46)Co_(0.36)Ni_(0.04)Zr_(0.14))_(100-x)Ta_x非晶合金复合材料磁性能和力学性能的影响

利用铜模吸铸法制备出直径为3 mm的(Fe0.46Co0.36Ni0.04Zr0.14)100-xTax(x=0,4,8,12)非晶合金复合材料柱状试样,通过X射线衍射(XRD)、选区电子衍射(SAED)、振动样品磁强计(VSM)、微机控制电子式万能力学试验机和扫描电镜(SEM)研究了不同Ta含量对合金的磁性能和压缩力学性能的影响。结果表明,随着Ta含量的增加,合金中不断有晶体相Co2Zr、Co2Ta0.5Zr0.5析出,合金的矫顽力Hc呈现出减小的趋势,而合金的饱和磁化强度Ms、抗压强度σbc和弹性应变εe则呈现出先增加后减小的趋势。当x=4时,合金的Ms、σbc和εe均达到最大值,分别为137.70A·m2/kg、1 814 MPa和4.583%。说明选取合适的Ta含量能够明显改善(Fe0.46Co0.36Ni0.04Zr0.14)100-xTax非晶合金复合材料的磁性能和力学性能。     

热分解气氛对溶胶-凝胶法制备BLT铁电薄膜性能的影响

研究了热分解气氛对溶胶-凝胶法制备在Pt/Ti/SiO2/Si衬底上的Bi3.25La0.75Ti3O12 (BLT)薄膜铁电性能的影响.在400℃时空气或氧气气氛下热分解20min,接着在700℃时氧气气氛下退火30min.氧气气氛下的热分解能充分分解掉薄膜中的有机成分,而空气气氛下的热分解使炭、氢有机成分部分残留在薄膜中.有机成分的不完全分解影响了退火过程中BLT薄膜晶化时晶粒的生长.表现出生长取向和晶粒尺寸对BLT薄膜铁电性能的影响.氧气和空气气氛下热分解的薄膜的剩余极化(Pr)和矫顽电场(Ec)分别为18.85μC/cm2,119.7kV/cm和12.56μC/cm2、112.5kV/cm.氧气气氛下热分解的薄膜的剩余极化值显著提高.所以热分解是控制铁电性能的重要步骤.     

羰基铁/聚苯乙烯复合材料的制备及微波吸收性能

采用热压法制备了羰基铁/聚苯乙烯复合材料。复合材料的结构、形貌和电磁性能分别采用X射线衍射仪(XRD)、扫描电镜(SEM)和HP8510网络分析仪进行了研究。结果表明,随着羰基铁粉含量的增加,羰基铁/聚苯乙烯复合材料的复介电常数的实部ε′和虚部ε″、复磁导率的实部μ′和虚部μ″都呈现逐渐增大的趋势。羰基铁粉含量为75%(质量分数)的羰基铁/聚苯乙烯复合材料具有最好的电磁波吸收性能,其最小反射率在14GHz为-15dB,-10dB带宽达4.1GHz。     

高抗弯聚丙烯/有机化锂皂石复合材料的制备与性能

采用十六烷基三甲基溴化铵(CTAB)对锂皂石(Laponite)进行修饰,得到有机化锂皂石。采用聚丙烯接枝马来酸酐(PP-g-MAH)作为增容剂,制备了一种具有高抗弯模量和高断裂伸长率的聚丙烯/有机化锂皂石复合材料,考察了有机化锂皂石对复合材料性能的影响。结果表明,当有机化锂皂石的用量增加时,复合材料的弯曲模量增加,断裂伸长率则先增加后降低。当有机化锂皂石质量分数仅为1%时,复合材料弯曲模量达到1230 MPa,相比纯PP提高约35%;复合材料的断裂伸长率达到700%,相比于纯PP,提高约25%。扫描电子显微镜结果显示,有机化锂皂石在聚丙烯基体中分布均匀,粒径在0.5μm~1μm之间,与聚丙烯基体结合良好。     

有机改性蒙脱土对聚乙烯稳定性影响

用甜菜碱为有机改性剂对蒙脱土(MMT)进行有机改性,使其变为有机蒙脱土(O-MMT),并采用熔融插层法制备了聚乙烯/有机蒙脱土(PE/O-MMT)复合材料。通过特性黏度分析了不同含量有机改性蒙脱土的聚乙烯/有机蒙脱土复合材料样品膜在人工加速老化实验下的光降解特性,并采用扫描电镜分析了有机蒙脱土含量为0%和4%的聚乙烯/有机蒙脱土复合膜表面形貌。结果表明:有机改性蒙脱土(O-MMT)能有效提高聚乙烯的光降解稳定性。     

(1-x)CaTiO_3/xNi_(0.5)Zn_(0.5)Fe_2O_4复合材料的制备及其性能

采用固相反应法合成了(1-x)CaTiO3/xNi0.5Zn0.5Fe2O4(0≤x≤1.0)复合材料,并研究了复合材料的物相、微观结构、介电性能和磁性能。结果表明:样品中仅含有钙钛矿型CaTiO3和尖晶石型Ni0.5Zn0.5Fe2O4。1260℃保温3h,样品相对密度达到98.91%,颗粒尺寸约为2μm。样品介电常数随Ni0.5Zn0.5Fe2O4含量(x)增加而增大。当x=0.7、测试频率为103 Hz时,样品介电常数(εr)和介电损耗(tanδ)分别为2629.18和1.74。(1-x)CaTiO3/xNi0.5Zn0.5Fe2O4复合材料显示磁性。其中x=0.7时,样品饱和磁化强度(Ms)达到49.07A·m2/kg;这归因于Ni0.5Zn0.5Fe2O4具有优异的磁性能。     

1-3型压电纤维复合材料的制备及性能研究

用粉末-溶胶混合物挤出法制备了直径为300μm和400μm的PZT压电纤维,研究了纤维的显微结构、密度和收缩率.采用排列-浇铸法制备了纤维体积分数为25%的1-3型压电纤维复合材料,计算了材料的介电常数、机电耦合系数和机械品质因数.结果表明:1-3型压电复合材料的Kp小于压电陶瓷片,Kt和Kt/Kp都大于陶瓷片;相同体积分数的压电纤维复合材料,直径为400μm的纤维制备的复合材料其εT,d33,Kt和Kt/Kp都大于直径为300μm的纤维制备的复合材料.     

蒙脱土填充木塑复合材料的弯曲性能和蠕变特性

对蒙脱土进行有机插层改性制得有机蒙脱土(OMMT),用硅烷接枝木粉制备了有机蒙脱土/木粉/聚氯乙烯(OMMT/WF/PVC)纳米复合材料。加入的接枝木粉与OMMT分散在界面上起增强作用,有助于提高复合材料性能。用质量分数1.5%的偶联剂处理木粉,添加质量分数1.5%的OMMT时,复合材料的弯曲性能和抗蠕变性最好。用KWW模型和广义Voigt模型分析了蠕变曲线。     

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