PP/PA6原位成纤复合材料 I.形态与力学性能

不相容的通用热塑性塑料聚丙烯（ＰＰ）和尼龙６（ＰＡ６）共熔挤出，当ＰＡ６为分散相时，得到了ＰＡ６纤维分散于ＰＰ基体中的原位复合材料。在ＰＰ和ＰＡ６的熔点之间成型，可以保持住纤维的形态。材料的拉伸强度下降，但冲击强度得到大幅度提高。     

聚丙烯共混改性研究

将少量（１％）自制的甲基丙烯酸十八醇酯（ＳＭＡ）与丙烯酰胺（ＡＭ）共聚物Ｐ（ＳＭＡ－ＡＭ）添加剂聚丙烯（ＰＰ）中进行共混，能大幅度提高聚丙烯的亲水性和粘合强度。Ｐ（ＳＭＡ－ＡＭ）的加入，改善了ＰＰ的流变性能，对ＰＰ的结晶度和拉伸强度影响不大。俄歇电子能谱（ＡＥＳ）分析表明，Ｐ（ＳＭＡ－ＡＭ）在ＰＰ共混物表面富集。     

液晶环氧树脂增韧改性E-51树脂体系性能研究

目的研究液晶环氧树脂含量对E-51树脂体系固化性能和力学性能的影响。方法采用动态DSC法,研究了液晶环氧树脂对固化反应性的影响;采用力学性能测试和扫描电镜的方法,研究了液晶环氧树脂对固化物力学性能的影响,及其增韧机理。结果液晶环氧树脂含量越高,树脂体系固化反应越快。液晶环氧树脂的加入使冲击强度、弯曲强度和拉伸强度均得到提高。结论液晶环氧树脂质量分数为7%的配方,冲击强度和弯曲强度最高;质量分数为10%的配方拉伸强度最高。     

聚氨酯改性环氧树脂/聚苯乙烯SIPNs固化动力学(Ⅰ) 环氧树脂固化剂含量对体系固化过程的影响

用化学滴定,粘度测定等方法,研究了环氧树脂固化剂（Ｔ３１）用量对聚醚型聚氨酯改性双酚Ａ型环氧树脂（ＰＵＤＧＥＢＡ）／聚苯乙烯（ＰＳｔ）室温同步ＩＰＮｓ体系固化动力学行为的影响。研究结果表明,增加Ｔ３１的用量,可以大大地缩短上述体系的凝胶时间。两个网络固化速度的峰值相对位置未改变。苯乙烯的固化受扩散控制,反应级数为２．０级;ＰＵＤＧＥＢＡ的固化为自动催化机理,反应级数为３．０级。     

超支化聚酯基二茂铁/环氧树脂复合材料的制备及性能

以第3代环氧端基脂肪族超支化聚酯（EHBP）增韧的环氧树脂（E-51）为基体材料,超支化聚酯基二茂铁（HBPE-Fc）为吸波剂,制备具有一定力学承载及电磁性能的超支化聚酯基二茂铁/环氧树脂（HBPE-Fc/E-51）复合材料,并通过力学性能测试及扫描电镜、矢量网络分析仪等研究了该复合材料的力学及电磁性能。结果表明,添加较低含量的HBPE-Fc能较好地改善环氧树脂体系的拉伸及冲击性能,第4代HBPE-Fc质量分数为2%时,与纯环氧树脂体系相比,HBPE-Fc/E-51复合材料的拉伸强度、断裂伸长率和冲击强度分别提高了21.81%、34.32%和15.41%,对固化体系的拉伸断面分析发现引入HBPE-Fc后材料表现出韧性断裂。HBPE-Fc/E-51复合材料的玻璃化转变温度在105.29~130.27 ℃之间,具有良好的热稳定性,同时该复合材料具有一定的电磁特性。     

环氧树脂／液晶化合物固化体系形态与力学性能的研究

用偏光显微镜研究了环氧树脂（EP）／液晶化合物固化体系在固化过程中,不同温度、不同反应时间、不同的液晶聚合物加入量下体系的形态变化,用力学方法和差热分析仪（DSC）测试了不同液晶聚合物加入量下固化物的力学性能和玻璃化转变温度（Tg)。结果表明：起始固化温度、固化时间、共混方式都对固化体系中液晶的有序结构有较大影响,加入不同含量的液晶聚合物,均可以使固化物的冲击强度、拉伸强度、弯曲强度、模量和Tg提高,其中冲击强度最大提高3.5倍,拉伸强度提高1.6倍,弯曲强度提高1.26倍,弯曲模量提高1.1倍,Tg提高60℃。     

共混合金力学性能的研究 Ⅱ.CPE,ACR对PVC共混体系力学性能的影响

在上文的基础上，对ＰＶＣ／ＣＰＥ／ＰＰ和ＰＶＣ／ＡＣＲ／ＰＰ三元共混体系的力学性能进行研究。结果表明，随着ＣＰＥ或ＡＣＲ用量的增加，不但共混合金的冲击强度增加，而且共混合金由刚性体ＰＰ增韧时所产生的最大值的幅度也有所提高，其趋势是ＣＰＥ或ＡＣＲ用量越多，产生最大值时刚性体分散相ＰＰ所需的量越多，同时冲击强度最大值增加的幅度也越大。ＰＰ对共混合金无增强作用，ＡＣＲ对共混合金拉伸强度和断裂伸长率的影响比ＣＰＥ的大。     

咪唑封端扩链脲改性环氧树脂E-51/酸酐MTHPA体系性能研究

以端羟基聚环氧丙烷1000，甲苯二异氰酸酯（TDI），2－甲基咪唑为原料，合成了扩链脲TI，利用DSC，动态热机械分析仪DMA，冲击试验机及扫描电镜（SEM）等手段对TI改性的环氧树脂E－51／甲基四氢化邻苯二甲酸酐（MTHPA）固化体系的反应活性，动态力学行为，冲击性能，断裂面形态结构进行了系统研究，结果表明，改性后的E－51／MTHPA体系反应活性明显提高，固化反应峰顶温度较未改性体系降低160℃－200℃，固化反应的表观活化能由未改性体系的160．3kJ/mol降至63kJ/mol-87kJ/mol，同时与未改性体系相比，经过改性的环氧树脂固化体系冲击强度有较大的提高，在TI含量为5％时体系的玻璃化转变温度Ts达到最高，各改性体系冲击断面呈韧性断裂。     

改性聚醚增韧环氧树脂的研究

采用来源广泛，价廉的聚醚、桐油和顺丁烯二酸酐合成了新的环氧树脂改性剂。探讨了含有新改性剂的环氧树脂体系的固化特征，相分离历程以及相结构对力学性能的影响。含有新改性剂的环氧树脂是一个多相分散体系，其冲击强度从未改性环氧树脂的６．８ｋｇｃｍ／ｃｍ２，提高到４７．２ｋｇｃｍ／ｃｍ２。     

高性能热塑性树脂增韧聚苯硫醚的韧性

研究了高性能热塑性树脂双酚Ａ型聚砜（ＰＳＦ）、酚酞型聚醚酮（ＰＥＫ－Ｃ）增韧聚苯硫（ＰＰＳ）的破坏韧性和破坏形态。实验表明：ＰＳＦ与ＰＥＫ－Ｃ两种材料的加入都能改善ＰＰＳ的冲击强度和破坏韧性。不同共混（加入）方法对ＰＳＦ／ＰＰＳ与ＰＥＫ／－Ｃ／ＰＰＳ两体系的增韧效果有效果。     

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.……     

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...     

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.     

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.     

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 ...