云母和纤维组合增强聚丙烯复合材料 I.力学性能研究

以云母填充聚丙烯为基体,连续无规玻璃纤维毡为增强材料,通过双钢带压机制成了云母填充GMT（Glass Mat Reinforced Thermoplastic)。研究了云母的加入对GMT力学性能的影响。结果表明,少量云母的加入,使GMT的力学性能发生明显变化,强度和刚性显著提高,云母和纤维表现出正的组合效应;随着云母填充量增加,GMT的强度和模量下降,云母与纤维的组合表现出负效应,云母对GMT力学性能的影响主要与云母的加入引起的玻璃纤维与聚丙烯基体之间的界面结合有关,少量云母的加入使玻璃纤维与基体的界面结合强度提高,而大量云母的加入则造成纤维与基体界面结合强度下降,向基体中添加马来酸酐接枝聚丙烯（MPP）,通用效改善云母含量较高情况下纤维与基体的界面结合状况,使高填充云母GMT表现出优良的力学性能,还研究了云母粒径对云母填充GMT力学性能的影响。     

云母和纤维组合增强聚丙烯复合材料Ⅰ.力学性能研究

以云母填充聚丙烯为基体,连续无规玻璃纤维毡为增强材料,通过双钢带压机制成了云母填充ＧＭＴ（Ｇｌａｓｓ Ｍａｔ Ｒｅｉｎｆｏｒｃｅｄ Ｔｈｅｒｍｏｐｌａｓｔｉｃ）．研究了云母的加入对 ＧＭＴ力学性能的影响,结果表明,少量云母的加入,使ＧＭＴ的力学性能发生明显变化,强度和刚性显著提高,云母和纤维表现出正的组合效应;随着云母填充量增加,ＧＭＴ的强度和模量下降,云母与纤维的组合表现出负效应,云母对ＧＭＴ力学性能的影响主要与云母的加入引起的玻璃纤维与聚丙烯基体之间的界面结合有关,少量云母的加入使玻璃纤维与基体的界面结合强度提高,而大量云母的加入则造成纤维与基体界面结合强度下降,向基体中添加马来酸酐接枝聚丙烯（ＭＰＰ）,能有效改善在云母含量较高情况下纤维与基体的界面结合状况,使高填充云母ＧＭＴ表现出优良的力学性能　还研究了云母粒径对云母填充ＧＭＴ力学性能的影响,     

云母填充聚丙烯的界面和力学性质的研究

研究了云母填充聚丙烯体系,通过云母的不同表面处理改变填料的表面性质,以及添加接枝改性聚丙烯作为界面改性剂,考察了不同的界面状况对体系加工流动性以及材料力学性能的影响。实验结果表明,有机偶联剂等表面处理剂有助于填料的分散。带有机长链的处理剂可明显降低体系的熔体粘度,但力学性能未提高,表现出界面润滑效应。硅烷偶联剂处理的云母与聚丙烯熔体的加工混合能接近于未处理体系,但熔混后压制的试样抗张强度显著提高,表现出界面“偶联”效应。添加少量的马来酸酐接枝聚丙烯,与带氨基的硅烷偶联剂相配合,可使填充聚丙烯的抗张强度和断裂伸长都大大提高,表现出界面的强偶联作用。     

偶联剂用量对玻璃纤维增强聚丙烯性能的影响及表征

研究了偶联剂用量对玻璃纤维增强聚丙烯复合材料力学性能的影响,并通过扫面电镜对玻璃纤维增强聚丙烯的界面及冲击断面进行研究.结果表明,玻璃纤维含量固定在35％时,偶联剂用量约为1％时,冲击强度最高.经偶联剂处理,可以明显增强玻璃纤维与聚丙烯基体的界面结合,改善复合材料的力学性能.     

云母增强β型聚丙烯

研究了云母填充β型聚丙烯体系，比较了云母填充α、β型聚丙烯的力学性能，结果发现，体系中加入PP-g-MAH界面改性剂时，β型体系力学性能优于α型．同时通过广角X射线衍射(WAXD)分析了云母和PP—g-MAH加入对β型聚丙烯晶型、晶体结构参数如微晶尺寸等的影响．发现云母的加入使PP微晶尺寸有所增加，聚丙烯的晶胞参数变小，而PP—-g-MAH作用基本相反，PP—g-MAH不利于β型聚丙烯的形成，但利于云母的取向，从而利于力学强度的提高．     

云母和纤维组合增强聚丙烯复合材料Ⅱ.界面性能研究

用单丝拔出法测定了云母和纤维组俣增强聚丙烯合材料中纤维与基体之间的界面结合强度，测定了云母和纤维组合增强聚丙烯复合材料的结晶温度，动态储存模量和线膨胀系数，并计算了纤维因基体体积收缩而形成的径向热残余压缩应力和基体与纤维之间的摩擦系数，研究了云母对纤维和基体界面性能的影响，结果表明，云母的加入使纤维受到的残余应力增加，摩擦系数显著下降，导致基体与纤维界面的结合强度随云母含量的增加先上升后下降。     

纤维表面处理与基体改性对连续玻纤增强聚丙烯力学性能的影响

考察了连续玻纤的表面处理、基体的接枝改性及接枝单体的种类和接枝产物的加入量对连续玻纤毡增强聚丙烯(CGFRPP) 力学性能的影响, 并通过红外光谱、扫描电镜对CGFRPP 的界面化学作用及界面粘结进行了研究。结果表明, 马来酸酐接枝改性聚丙烯与未经偶联剂处理的玻纤不能形成有效的化学结合, 而与经硅烷偶联剂表面处理的玻纤可发生明显的化学作用, 形成良好粘结, 显著提高CGFRPP 的力学性能; 硅烷偶联剂的种类对以改性PP 为基体的CGFRPP 力学性能的影响不大; 马来酸酐接枝聚丙烯比丙烯酸接枝聚丙烯对CGFRPP 力学性能的改善更为有效。      

马来酸酐接枝聚丙烯对云母填充聚丙烯的增容作用

以马来酸酐接枝聚丙烯（MPP）为云母填充聚丙烯（PP/mica)的界面相容剂，研究了MPP的添加量对PP/mica的力学,同观形态以及PP/mica熔体的流变行为和非等温结晶行为的影响。结果表明，加入MPP使PP/mica的国学得以全面的提高，PP/mica样品断面的电镜照片表明，MPP的加入使云母与聚丙烯的界面粘结得到改善；PP/mica熔体的表观粘度明显高其聚丙烯基体，随着MPP含量的增加，PP/mica的表观粘度下降，幂律指数也发生变化，云母对聚丙烯具有明显的成核,但随MPP含量的增加，云母的成核效率逐渐减弱。     

含柔性链大分子偶联剂对SF/PP木塑复合材料结构和性能的影响

合成含柔性链段的大分子偶联剂,以此作为剑麻纤维(SF)/聚丙烯(PP)木塑复合材料的界面相容剂,研究其对复合材料力学性能、热性能、晶态结构和微观结构的影响,提出复合材料界面增容的机理。实验结果表明,经含柔性链段大分子偶联剂表面处理SF后,复合材料的界面相容性得到显著改善,冲击强度可达22.08kJ/m2,比未经偶联剂处理的复合材料提高了49.4%;热稳定性和PP相的结晶速率及结晶度有所提高,晶态结构无变化,仍是典型的α晶型。     

填充聚丙烯的界面对流变和力学性能的影响

本工作利用RMS-605大型流变仪等仪器研究三种不同几何形状的填料包括碳酸钙粉末、玻璃微珠和云母填充聚丙烯体系,通过不同表面处理改变填料的表面性质,研究了不同界面状态对体系稳态与动态粘弹性质以及力学性能的影响.     

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.