聚醚型聚氨酯／乙烯基酯树脂互穿聚合物网络结构？…

以聚氨酯（ＰＵ）为组分Ｉ,乙烯工酯树脂（ＶＥＲ）为组分Ⅱ,采用二步法制备了聚氨酯／乙烯基酯树脂互穿聚合物网络（ＰＵ／ＶＥＲ－ＩＰＮ）采用透射电镜（ＴＥＭ）和原子显微镜观察了ＰＵ／ＶＥＲ－ＩＰＮ的微观形态,用调制ＤＳＣ（Ｍ－ＤＳＣ＾ＴＭ）动态力学分析方法（ＤＭＡ）研究了ＩＰＮ的玻璃化转变行为及动态力学性能,结果表明,ＰＵ网络与ＶＥＲ网络形成了多相微区结构,在界面处互穿和缠结,形成类似胞状的结构,ＰＵ     

RIM聚氨酯／乙烯基酯树脂互穿聚合物网络的形态及力学性能研究

研究了适用于反应注射成型（ＲＩＭ）过程的含聚氧化丙烯三元醇软段的聚氨酯（ＰＵ）与乙烯基酯树酯（ＶＥＲ）形成的互穿聚合物网络（ＩＰＮ）的形态与力学性能，发现ＶＥＲ与ＰＵ网络能较好地互穿，但由两种异氰酸酯（甲苯二异氰酸酯，ＴＤＩ；碳二亚胺改性二苯基甲烷二异氰酸酯，ＭＤＩ）在接近室温条件下形成的ＩＰＮ的形态与力学性能，与这两个网络在各自放热条件下形成的ＩＰＮ有较大差异。这与由前者形成的材料形态中存在明显的ＰＵ硬段远程有序结构有关。该材料的力学性能研究在明，刚性的ＶＥＲ网络或弹性的ＰＵ网络对两种由不同异氰酸酯形成的ＩＰＮ材料均有较明显的增强效果或增韧效果。     

RIM聚氨酯／乙烯基酯树脂互穿聚合物网络的形态及力学性…

研究了适用于反应注射成型（ＲＩＭ）过程的含聚氧化丙烯三元醇软段的聚氨酯（ＰＵ）与乙烯基酯树酯（ＶＥＲ）形成的互穿聚合物网络（ＩＰＮ）的形态与力学性能，发现ＶＥＲ与ＰＵ网络能较好地互穿，但由两种异氰酸酯（甲苯二异氰酸酯，ＴＤＩ；碳二亚胺改性二苯基甲烷二异氰酸酯，ＭＤＩ在接近室温条件下形成的ＩＰＮ的形态与力学性能，与这两个网络在各自放热条件下形成的ＩＰＮ有较大差异。这与由前者形成的材料形态中存在明显的     

聚碳酸亚丙酯型聚氨酯／聚甲基丙烯酸甲酯互穿网络？…

用同步法合成了聚碳酸亚丙酯聚氨酯／聚甲基丙烯酸甲酯互穿网络聚合物（ＰＰＣＰＵ／ＰＭＭＡ ＩＰＮ）,调节ＩＰＮ中两组分配比制备出多种高聚物合金。用ＤＳＣ、ＴＥＭ对ＩＰＮ的研究结果表明,ＰＰＣＰＵ／ＰＭＭＡ ＩＰＮ的两组分是互不相容的。同时对各种组成比的ＩＰＮ材料进行了力学性能测试,并用ＳＥＭ对断面进行了观察解释。实验结果发现,ＩＰＮ的密度大于相应体系体积加和值。     

PU软段结构对PU／PMMA IPN中两组分相容性的影响

用同步法合成了４种聚氨酯／聚甲基两烯酸甲酯互穿聚合物网络／（ＰＵ／ＰＭＭＡ ＩＰＮ）利用ＤＤＣ、ＴＥＭ和动态力学谱（ＤＭＳ）等手段综合研究了ＩＰＮ中两组分的相容性和相态结构，用基团贡献加和方法计算了各种ＰＵ和ＰＭＭＡ的溶度参数δ，结合ＰＵ软段链结构讨论了各种ＩＰＮＫ呈现不同相容性和相态结构的原因。     

聚氨酯／环氧树脂互穿网络聚合物相行为与粘接剪切性能的研究

制备了一系列聚氨酯／环氧树脂互穿聚合物网络ＰＵ／ＥＰＩＰＮｓ。由ＤＳＣ、ＴＭＡ和ＤＤＶ研究表明，ＩＰＮｓ在高温区存在单一的玻璃化转变温度Ｔｇ，ＩＰＮｓ的相行为与其粘接剪切强度相关。并确认接枝共聚物的存在增强了ＩＰＮｓ的互穿效应     

聚氨酯／环氧树脂互穿网络聚合物相行为与粘接剪切性…

制备了一系列聚氨酯／环氧树脂互穿聚合物网络ＰＵ／ＥＰ ＩＰＮｓ，由ＤＣＳ、ＴＭＡ和ＤＤＶ研究表明，ＩＰＮｓ在高温区存在单一的玻璃化转变温度，Ｔｇ，ＩＰＮｓ的相行为与其粘接剪切强度相关，并确认接枝共聚物的存在增强了ＩＰＮｓ的互穿效应。     

聚环氧氯丙烷聚氨酯／聚苯乙烯IPN的玻璃化转变行为

用ＤＳＣ和动态弹粘谱（ＤＭＳ）研究了聚环氧氯丙烷聚氨酯／聚苯乙烯互穿聚合物网络「ＰＵ（ＰＥＣＨ）／ＰＳＩＰＮ」的玻璃化转变行为，发现，当ＩＰＮ中聚苯乙烯（ＰＳ）含量大于２０％（质量分数）时，ＩＰＮ是不相容体系，有两个玻璃化转变，ＰＳ交链度的增加，对应于ＰＵ的玻璃化转变（ＴｇＩ）不变，对应玻璃化转变（ＴｇＩＩ）向高温方向移动，转变越来越不明显，加入氨酯反应催化剂时，Ｔｇ明显内移，Ｔｇｆｆ内移超过２０     

聚氨酯／环氧树脂互穿网络聚合物相行为与断裂拉伸强度

制备了一系列聚氨酯／环氧树脂互穿网络聚合物ＰＵ／ＥＰＩＰＮ，由ＤＳＣ，ＴＭＴ和动态粘弹仪研究表明，ＩＰＮ在高温区存在的单一玻璃化转变温度Ｔｇ，ＩＰＮ的的相行为与其断裂伸强度的相关，并确认接枝共聚物的存在增强了ＩＰＮ的互穿效应。     

PMMA／PBA乳胶IPN阻尼材料的研究

用乳液聚合方法合成了一系列的互穿聚合物网络，其中包括：ＰＭＭＡ／ＰＢＡ和Ｐ（ＭＭＡ－ｃｏ－ＰＭＡ）／ＰＢＡ乳胶互穿聚合物网络（ＬＩＰＮ），ＰＭＭＡ／ＰＢＡ乳胶双向互穿聚合物网络（ＬＢＩＰＮ）以及ＰＭＭＡ／ＰＢＡ界面交联互穿聚合物网络（ＩＣＬＩＰＮ）。动态力学谱和拉伸试验结果表明：（１）ＰＭＭＡ／ＰＢＡ互穿聚合物网络的两组分相容性和阻尼性能可通过ＭＭＡ和ＰＭＡ共聚来改善；（２）双向互穿技术是一种行之     

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.