RSMA增容PA6/PP共混物的形态结构与增容机理

采用ＲＳＭＡ为增容剂制备了ＰＡ６／ＰＰ共混物,研究了ＲＳＭＡ增容ＰＡ６／ＰＰ共混物的形态结构和热行为以及晶态结构,并探讨ＲＳＭＡ增容ＰＡ６／ＰＰ共混物的增容机理结果表明,ＰＡ６／ＰＰ共混物为热力不相容的海岛型两相结构,ＲＳＭＡ的加入改善ＢＰＡ６与ＰＰ相间的相容性,使两相分均匀,分散度提高。ＲＳＭＡ对ＰＡ／ＰＰ共混物的增容机理可用界面－分散相复合模型描述。     

聚氧化乙烯与聚乙烯醇共混体系的研究

采用水溶液共混法制备共混物，研究了聚氧化乙烯与聚乙烯醇共混体系的相容性及共混体系中各组分的结晶性。实验结果表明，ＰＥＯ／ＰＶＡ共混物为不相容共混体系。ＰＶＡ分子间易于形成氢键是此共混体系不相容的主要原因。ＰＥＯ／ＰＶＡ共混体系为相分离结构，ＰＥＯ及ＰＶＡ皆可在各自的相区内形成结晶。体系中ＰＶＡ的存在不影响ＰＥＯ的结晶能力，共混体系在组成为５０／５０左右其力学性能有急剧变化，提示在此时发生了相倒转。     

聚碳酸酯／聚甲基丙烯酸甲酯共混体系的研究

本文研究了ＰＣ／ＰＭＭＡ共混体系的拉伸行为、热行为及形态。结果表明，共混物的拉伸模量、屈眼应力随ＰＭＭＡ含量增加略有增大。断裂伸长率及断裂功在ＰＭＭＡ含量低于５０％时呈正协同效应，在１０～３０％处出现极大值。ＰＣ／ＰＭＭＡ为两相体系，分散相ＰＭＭＡ的粒径小于２μｍ，对ＰＣ起增韧作用。     

HDPE／NBR共混物的超声行为研究

研究了不同丙烯腈含量的丁腈橡胶（ＮＢＲ）与高密度聚乙烯（ＨＤＰＥ）组成的共混物的超声行为，考察了共混物超声声速随组成变化的规律，首次发现不相容的ＨＤＰＥ／ＮＢＲ共混体系在丙烯腈含量较低时，共混物组成与声速仍呈线性关系。     

共聚物在不相容共混体系中界面行为的Monte Carlo模拟

用自由体积扩散(FVD)算法模拟了不同结构的共聚物在不相容熔融共混体系中的界面行为,模拟结果表明,加入少量共聚物后,共混体系的相分离程度明显降低,从其形貌来看,分散相相区尺寸变得更小,更分散.所有这些表明,加了共聚物作为增容剂后,共混体系的相容性有明显的提高.而交替共聚物比相应的二嵌段共聚物增容效果更好,与文献中报道的实验现象基本吻合.     

共聚物在不相容共混体系中界面行为的MontCarlo模拟

用自由体积扩散算法模拟了不同结构的共聚物在不同相容熔融共混体系中的界面行为,模拟结果表明,加入少量共聚物后,共混体系的相分离程度明显降低,从其形貌来看,分散相区尺寸变得更小。     

增容作用和动态固化对聚丙烯/环氧树脂共混物形态结构的影响

研究了增容作用和动态固化对聚丙烯(PP)/环氧树脂(EP)共混物形态结构的影响。实验结果表明,PP/EP共混物是不相容共混体系,当环氧树脂含量小于50%时,共混物中环氧树脂以分散相存在,PP为连续相。反之,则共混物的相态发生相反转,即环氧树脂为连续相,PP为分散相。加入马来酸酐接枝聚丙烯(M AH-g-PP)促进环氧树脂与PP的相容性,使得分散相的颗粒明显变小。与PP/EP和PP/M AH-g-PP/EP共混物不同,当环氧树脂含量大于50%时,动态固化PP/EP和PP/M AH-g-PP/EP共混物仍是环氧树脂分散相和PP连续相结构,未出现相反转。对于相同含量环氧树脂的共混物,动态固化PP/M AH-g-PP/EP共混物中环氧树脂分散相尺寸明显小于动态固化PP/EP共混物中环氧树脂分散相尺寸。     

聚己内酯/聚丁二酸丁二醇酯-聚己二酸丁二醇酯共聚物熔融共混体系的力学性能、结晶及流变行为研究

通过熔融共混制备了生物可降解的聚己内酯(PCL)/聚丁二酸丁二醇酯-聚己二酸丁二醇酯共聚物(PBSA)共混体系,采用万能拉力机、差示扫描量热仪(DSC)、旋转流变仪分别研究了共混体系的力学性能、结晶和流变行为。结果表明,PCL/PBSA为不完全相容的体系,共混体系的相形态依赖于共混物的组分比,随着PBSA组分含量的增加,相形态发生变化,存在不相容的相界面,适量的添加PBSA能改善PCL的结晶、流变及力学行为。     

顺酐改性乙丙三元胶／尼龙的共混研究

对极性差别较大的乙丙三元橡胶和尼龙1010体系,首次通过官能化反应及动态全硫化共混方法制得了一种耐温性较高的热塑性弹性体,并对相容性的表征及分散相粒径问题进行了研究。实验表明,上述共混体系仍是非均相的不相容体系,尼龙相的玻璃化转变温度向低温移动的程度可以作为相容程度的判断。此时,在两相界面间是橡胶向尼龙基质的渗透,渗透方向应该也对改性作用有其特有的贡献。同时分散相的最大填充体积φ_(max)可以用来表征相容性的优劣。     

PHB／PPO共混体系的相容性和结晶

采用溶液共混方法对聚β－羟基丁酸酯／聚氧化丙烯共混体系的相容性和结晶行为进行了研究，ＤＳＣ，ＰＯＭ，ＷＡＸＤ等实验结果表明，该体系不是相容体系。但在特殊的组成比下有相容的第三相存在。ＰＰＯ对ＰＨＢ的结晶结构无影响，但对ＰＨＢ的结晶速率和结晶完整性有很大的作用。     

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.