首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
紫外线辐照HDPE与尼龙—6相容性的研究   总被引:12,自引:4,他引:8  
采用IR,SEM,DSC和拉伸应力-应变曲线研究了紫外线辐照HDPE/PA6的相容性,结果表明,随紫外线辐照时间的增长,HDPE分子链上引入〉C=O-C-O-等极基团明显增加;PA6的粒径减小,与基体间界面作用加强;两组分玻璃化温度差减小;共混物拉伸应力-应变曲线上出现屈服点及拉伸冷流塑性形变。  相似文献   

2.
紫外线辐照HDPE与尼龙-6相容性的研究   总被引:2,自引:0,他引:2  
采用IR、SEM、DSC和拉伸应力-应变曲线研究了紫外线辐照HDPE/PA6的相容性,结果表明,随紫外线辐照时间的增长,HDPE分子链上引入C=O-C-O-等极性基团明显增加;PA6的粒径减小,与基体间界面作用加强;两组分玻璃化温度差(T_(g,PA6)-T_(g,HDPE))减小;共混物拉伸应力-应变曲线上出现屈服点及拉伸冷流塑性形变。当辐照时间达144h后,由于HDPE热稳定性明显变差,共混物韧性突降,拉伸应力-应变曲线上未出现屈服点。  相似文献   

3.
采用接触角测定、SEM、抽滤分析和力学性能的测试研究了紫外线辐照HDPE\PVA短纤维共混物的力学性能和相容性。结果表明,经紫外线辐照后,由于在分子链上引入了>C=O、-COOH、-OH等极性基团,HDPE与水的接触角变小,亲水性增加。在与PVA短纤维共混过程中,HDPE分子链上引入的含氧基团与PVA分子链上-OH基团形成氢键,增强了共混体系相界面相互作用,使共混物的拉伸强度和冲击强度得到了明显提高。当辐照时间超过144h,由于HDPE降解严重,共混物的韧性突降。  相似文献   

4.
紫舛线辐照HDPE/PVA短纤维共混物相容性及力学性能的 …   总被引:2,自引:1,他引:1  
采用接触角测定、SEM、抽滤分析和力学性能的测试研究了紫外线辐照HDPE/PVA短纤维共混物的力学性能和相容性。结果表明,经紫外线辐照后,由于在分子链上引入了〉C=O、-COOH、-OH等极性基团,HDPE与水的接触角度小,亲水性增加。在与PVA短纤维共混过程中,HDPE分子链上引入的含氧基团与PVA分子链上-OH基团形成氢键,增强了共混体系相界面相互作用,使共混物的拉伸强度和冲击强度得到了明显提  相似文献   

5.
紫外线辐照对HDPE结晶结构及化学结构的影响   总被引:1,自引:0,他引:1  
采用DSC、WAXD、元素分析、FT-IR、ESCA、GPC、交联度和密度测定,研究了紫外线辐照了HDPE的结晶结构及化学结构变化。结果表明,紫外线辐照后,HDPE的熔融温度降低、熔融热焓升高、结晶度增大、晶胞结构未发生变化;HDPE分子甸主了COOH、C=O、C-O、OOH、OH等含氧官能团,分子量降低,分子量分布加宽,基本无交联发生。  相似文献   

6.
HDPE/尼龙-6/EAA共混体系反应增容作用的研究EI   总被引:8,自引:1,他引:7  
通过Brabender、DSC、SEM和力学性能测试研究了在HDPE/尼龙-6共混过程中EAA对体系的增容作用、力学性能以及结晶行为的影响。研究结果表明,在反应共混过程中,EAA中丙烯酸链段与尼龙-6末端胺基发生了化学反应,就地形成的EAA-尼龙-6接枝共聚物对HDPE/尼龙-6体系有增容作用,因而明显减小了相区尺寸,提高了拉伸强度。由于在共混过程中有接枝共聚物形成,明显降低了尼龙-6的结晶。  相似文献   

7.
紫外线辐照HDPE与尼龙—6共混材料结构与力学性能的研究   总被引:5,自引:4,他引:1  
研究了紫外线辐照HDPE与PA6共混材料的微观形态、结晶结构、熔融行为及力学性能。SEM、WAXD、DSC结果表明,随紫外线辐照时间的增加,共混物中PA6的粒径减小,与基体作用加强,HDPE晶面间距增大,熔点、结晶度降低熔程变窄。力学测试结果表明,在紫外线辐照能明显提高共混材料(uHDPE/PA6:90/10)的拉伸强度、断裂伸长断理解能和冲击强度。当辐照时间超过144h,由于HDPE热稳定性明显  相似文献   

8.
紫外线辐照HDPE与尼龙-6共混材料结构与力学性能的研究   总被引:1,自引:0,他引:1  
研究了紫外线辐照HDPE与PA6共混材料的微观形态、结晶结构、熔融行为及力学性能。SEM、WAXD、DSC结果表明,随紫外线辐照时间的增加,共混物中PA6的粒径减小,与基体作用加强,HDPE晶面间距增大,熔点、结晶度降低,熔程变窄。力学性能测试结果表明,紫外线辐照能明显提高共混材料(uHDPE/PA6:90/10)的拉伸强度、断裂伸长率、拉伸断裂能和冲击强度。当辐照时间超过144h由于HDPE热稳定性明显降低,共混过程中HDPE热降解严重,共混物的韧性突降。  相似文献   

9.
本文用ASAP2000吸附仪测定了吸附性能优异的沥青基高比表面积新型活性碳(PHAC)的BET比表面积、用BJH和DRS法分析了其孔隙结构参数,用XPS测定了PHAC的表面元素组成及含氧官能团,对PHAC的表面形态结构进行了SEM和TEM观察。研究表明:PHAC具有高度发达且均匀的微孔结构,其表面含有一定量的C-O-C、C-OH、C=O、O=C-O等多种类型的含氧官能团。  相似文献   

10.
采用DSC、WAXD研究了紫外线辐照对高密度聚乙烯(HDPE)结晶性能的影响。结果表明,随辐照时间的增加,HDPE结晶度增大,熔融峰向低温方向移动,但晶胞结构基本保持不变。通过TGA对紫外线辐照HDPE的热稳定性进行了研究,采用486微机对紫外线辐照HDPE分解动力学方程:dα/dt=k(1—α) ̄n=Aexp(—E/RT)(1—α) ̄n进行了模拟,用Graftool图形处理软件对动力学方程进行了拟合,通过一条TGA曲线,即可在微机上计算频率因子(A)、分解活化能(E)、分解反应级数(n)等动力学参数。研究结果表明,随紫外线辐照时间的延长,HDPE起始分解温度、分解活化能、反应级数降低,频率因子升高。  相似文献   

11.
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.  相似文献   

12.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

13.
14.
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...  相似文献   

15.
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.  相似文献   

16.
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.……  相似文献   

17.
ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号