UHMWPE／LDPE共混物的结晶行为与力学性能

采用差热分析和相差显微镜方法研究了超高分子量聚乙烯(UHMWPE)与低密度聚乙烯(LDPE)的机械共混物的结晶行为及其力学性能。在所采用的单螺杆挤出共混条件下,UHMWPE基本上以填料方式被分散于LDPE基体中。两组分没有共结晶发生,熔体长时间热处理可使两组分相互作用增加,UHMWPE可使LDPE的屈服强度和模量增加,辊筒共混方法得到的共混物性能优于单螺杆挤出的共混物的性能。     

通用工程塑料/聚烯烃共混改性的研究进展

主要综述了通用工程塑料聚碳酸酯和尼龙等/聚烯烃共混体系的相容性，形态，力学性能等方面的研究进展。     

共混改性尼龙11合金的研究进展

论述了用聚烯烃、橡胶、液晶高分子、树形大分子及无机刚性粒子等对尼龙11进行增韧增强改性的研究发展,其中以聚烯烃类改性最为广泛,但需要一定的相容剂;而无机刚性粒子增韧增强是近年发展起来的新方法,它可以在提高材料韧性的同时,提高材料的拉伸强度。     

PP／PS共混体系相容性及共混纤维性能研究

研究了以聚丙烯（PP）为基质,聚苯乙烯（PS）为改性组分的PP／PS共混体系,其为热力学不相容体系,但通过选择合适的原料,共混体系可以获得较好的工艺相容性,纺丝和牵伸实验表明,共混改性树脂的可纺性良好,改性纤维的物理力学性能,挺刮性有明显提高。     

热塑性聚氨酯弹性体共混改性研究进展

本文综述了热塑性聚氨酯弹性体与聚烯烃、工程塑料和弹性体共混改性的研究进展现状及其应用。热塑性聚氨酯有耐老化性能差、阻燃性差、加工性能差、成本高等缺点，经共混改性后，一般都可降低成本，改善加工性能；热塑性聚氨酯既可增韧改性聚丙烯、聚苯乙烯、聚碳酸酯、聚甲醛等；而且它和氯化聚乙烯及聚氯乙烯共混可有效改善其阻燃性能和耐老化性能。     

锂离子电池用聚烯烃隔膜的改性

介绍了聚烯烃类隔膜在液态锂离子二次电池中的重要作用、制备方法及其优缺点和面对越来越广泛的应用需求该类隔膜所存在的主要不足;重点论述了针对目前聚烯烃隔膜低表面能、难以充分润湿及耐热性差的问题而进行改性的研究成果和现状;总结了所采用的物理涂覆、化学接枝、共混及凝胶填充等改性方法及其存在优缺点;最后提出了对于聚烯烃类隔膜改性未来发展趋势的展望.     

共混、复合改性SBS的研究进展

综述了各种聚合物(聚烯烃、聚苯乙烯、聚氯乙烯等)和无机粒子对热塑性弹性体SBS的共混、复合改性研究进展,重点介绍了改性SBS体系在制备、组成与性能方面的研究概况。并指出制备互穿网络热塑性弹性体或纳米复合热塑性弹性体是SBS改性的重要研究方向。     

淀粉/聚烯烃共混降解材料的发展趋势

本详细综述了淀粉／聚烯烃共混降解材料的研究进展，分析认为淀粉／聚烯烃共混降解材料与众多的降解材料相比有其独特的优势，然而它的降解周期较长制约了它的进一步发展。要解决该问题就要从增加共混物中的淀粉含量和提高聚烯烃的环境降解能力入手。提高淀粉含量使用包括偶联剂增容、相客剂增容9反应型和非反应型增容剂)以及提高淀粉的塑性等方法。而加入各种化学促进剂是提高聚烯烃环境降解能力的有效手段。只要解决以上两个问题，淀粉／聚烯烃共混物就可以成为一种理想的完全降解的环保材料。     

聚烯烃熔融接枝研究及应用

聚烯烃通过接技改性可扩大其应用领域。本文介绍了聚烯烃单组分和多组分熔融接枝反应及相关机理。讨论了复合引发剂、接枝单体、聚合物颗粒尺寸及反应设备等因素对熔融接枝反应的影响。同时列举了可用于汽车工业和废塑料回收的接枝聚烯烃与其他聚合物的共混改性方法     

废旧塑料包装改性共混再生节能减碳新主张(上)

废旧包装再生塑料再生料改性技术的种类很多,常用的有共混改性、填充改性、增强改性、增韧改性、接枝改性、催化裂解和热裂解等方法。根据废旧塑料共混改性是大力发展的高新技术,研究了再生塑料共混改性的技术方法,介绍了废旧塑料物理改性利用的相容剂,同时指出了废旧塑料的共混增容改性回收再生利用技术研发。     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

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...     

Roman iron and steel: A review

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.     

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.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.