第三相对0—3型钛酸铅／环氧树脂压电常数的影响

研究了第三相导电体碳和锗的加入对０－３型钛酸铅／环氧树脂复合材料压电常数ｄ３３的影响，指出对于提高复合材料的ｄ３３值，锗的效果优于碳。并探讨了锗的最佳掺入量及钛酸铅／环氧树脂／锗复合材料的极化条件。     

钛酸铅-环氧树脂压电复合材料的制备

为了制备高体积填充率的钛酸铅－环氧压电复合材料，本文采用了将环氧树脂的丙酮稀溶液与钛酸铅细粉混合再抽真空除去溶剂的方法，这样有利于环氧树脂与钛酸铅进行良好的、均匀的复合，大大减少了界面气孔，所制得的复合材料钛酸铅填充率高（体积填充率达７０％），复合材料表面光滑无宏观缺陷。压电性能测定结果表明：极化条件不同，ｄ３３的值也不同，介电常数ε３３均为４３。，样品能够达到稳定极化的最佳ｇ３３的值为：２３．１×１０－３Ｖ·ｍ·Ｎ－１。     

塑料对0－3型锆钛酸铅压电复合材料性能的影响

研究了不同塑料尼龙１０１０和Ｅ－２０环氧树脂与锆钛酸铅（ＰＺＴ）复合而成的压电复合材料的压电性能，结果表明，尼龙１０１０－ＰＺＴ压电复合材料比Ｅ－２０环氧树脂－ＰＺＴ具有较低的饱和极化电场和较短的饱和极化时间，而且前者比后者具有更高的压电常数。     

钛酸铅—环氧树脂压电复合材料的极化及压电性能研究

对钛酸铅／环氧树脂复合压电材料的极化性能进行了研究。结果表明,较高的极化电场强度和较高的极化温度均有利于压电复合材料压电性能的提高,但超过一定值时,材料会达到饱和极化状态,压电变常趋于稳定。     

塑料对0—3型锆钛酸铅压电复合材料性能的影响

研究了不同塑料尼龙１０１０和Ｅ－２０环氧树脂与锆钛酸铅（ＰＺＴ）复合而成的压电复合材料的压电性能，结果表明，尼龙１０１０－ＰＺＴ压电复合材料比Ｅ－２０环氧树脂－ＰＺＴ具有较低的饱和极化电场和较短的饱和极化时间，而且前者比后者具有更高的压电常数ｄ↑－３３。     

镀Cu碳毡／环氧树脂复合材料的研制

研究了镀Ｃｕ碳毡／环氧树脂（ＣｕＣＦ／ＥＰ）复合材料的制备，并探讨了镀Ｃｕ量对碳毡电阻率，复合材料电阻率及其电磁屏蔽效率的影响规律．经合理工艺制得的镀Ｃｕ碳毡（４００ｍｇ．ｇ－１Ｃｕ—ＣＦ）含量为３００ｍｇ．ｇ－１ＣｕＣＦ／ＥＰ复合材料，其电磁屏蔽效率可在２０～１０００ＭＨｚ范围内达到６０ｄＢ．     

镀Cu碳毡／环氧树脂复合的研制

研究了镀Ｃｕ碳毡／环氧树脂（ＣｕＣＦ／ＥＰ）复合材料的制备，并探讨了镀Ｃｕ量对碳毡电阻率，复合材料电阻率及其电磁屏蔽效率的影响规律，经合理工艺制得的镀Ｃｕ碳毡（４００ｍｇ．ｇ＾－１Ｃｕ－ＣＦ）含量为３００ｍｇ．ｇ＾－１ＣｕＣＦ／ＥＰ复合材料，其电磁屏蔽效率可在２０＝－１０００ＭＨＺ范围内达到６０ｄＢ。     

EP／MMT纳米复合材料的研究

综述了目前环氧树脂／黏土纳米复合材料的制备方法，介绍了环氧树脂／黏土纳米复合材料的优异性能，并对其增韧改性机理作了探讨，最后展望了环氧树脂纳米复合材料的应用前景。     

颗粒分散型纳米复合材料的研究

采用溶胶-凝胶法制备了粒径为30～50nm锆钛酸铅PZT纳米压电粉体.将PZT纳米粉分散于环氧树脂中得到具有0-3连通性的颗粒分散型纳米复合材料.讨论了影响PZT纳米粉体合成、纳米粉体分散均匀性和压电复合材料性能的主要因素,包括pH值、粘度、超声波分散与柠檬酸三铵分散、PZT纳米粉的含量等.     

界面改性对钛酸铅／环氧树脂压电复合材料性能的影响

采用ＫＨ－５５０对钛酸铅粉末进行表面处理。通过对ＰＴ／环氧树脂和处理ＰＴ／环氧树旨两种压电复合材料的压电应变常数,耐热性和耐冲击强度的测定和对比,研究了界面改性对压电复合材料的压电性能的影响。结果表明：通过界面改性,可以明显提高复合材料的耐热性和耐击穿强度,耐对饱和极化时的压电应变常数无影响。     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

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