反应型液晶化合物改性环氧树脂的性能

利用自行合成的端基含有活性基团的热致性液晶化合物(LCEU)改性环氧树脂CYD-128／4，4’-二氨基二苯砜(DDS)固化体系，用DMA测试了共混物的动态力学性能并研究其结构与性能的关系，对改性体系的冲击强度、拉伸强度、弯曲强度、弹性模量、断裂伸长率、热失重温度(TG)与LCEU含量的关系进行了探讨，用扫描电镜(SEM)对材料断面的形态结构进行了研究。结果表明，经LCEU改性的共混物的α、β转变温度提高，橡胶态模量提高，材料的力学性能和热稳定性提高，改性后材料断裂面的形态逐渐呈现韧性断裂特征。     

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℃。     

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 2 6倍 ,弯曲模量提高 1 1倍 ,Tg提高 60℃     

高分子硅烷偶联剂改性环氧树脂性能研究

采用侧链氨基硅油(AEAPS)和小分子偶联剂KH-560为原料合成了一系列氨基硅油高分子偶联剂(APCA)并用作双酚A型环氧树脂(EP)/4,4′-二氨基二苯基甲烷(DDM)体系的改性剂,系统研究了改性剂含量等对改性环氧固化物的冲击强度、拉伸强度、断裂伸长率、玻璃化转变温度(Tg)和断裂面形态等的影响。结果表明,APCA能明显提高固化体系的性能,其中环氧树脂经10份APCA-60改性后,与未改性环氧相比,抗冲强度提高了近一倍,断裂伸长率增加了94.55%,拉伸强度也提高了59.55%,而Tg也提高了5℃,达到了明显的增强增韧和提高耐热性等效果。     

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。     

联苯型液晶聚氨酯增韧改性环氧树脂的制备与性能

合成了联苯型液晶聚氨酯(LCPU),并以其为增韧剂对环氧树脂(EP)进行增韧改性,研究了LCPU含量对LCPU/EP复合材料力学性能的影响。利用X射线衍射、动态粘弹谱仪、扫描电镜等手段对LCPU/EP复合材料的动态热力学性能及断裂面的微观形貌进行了研究。结果表明,LCPU的加入可使LCPU/EP复合材料的冲击强度提高2倍～3倍,弯曲强度增加了40%～60%,材料的玻璃化转变温度(Tg)及储能模量(E′g)也有很大程度的提高。     

聚醚扩链脲增韧环氧树脂/双氰双胺固化体系

以聚醚PPGl000、异氰酸酯、二胺为原料，合成了聚醚扩链脲(EU)，系统考察了EU改性的环氧树脂E一51／双氰双胺(dicy)固化体系的固化反应活性、动态力学行为、冲击性能和断裂面形态结构。并对体系的冲击性能、形态结构与动态力学行为之间的关系进行了探讨。结果表明，改性体系固化反应活性明显提高，固化反应表现活化能降低，固化反应峰顶温度从190℃降低至140℃，固化反应的表现活化能由145．5kJ／mol降至73．6kJ／mol；改性体系冲击强度明显提高，较未改性的E-51／dicy体系提高了9倍，较小分子取代脲改性的E-51／dicy体系提高了7倍；其冲击试样断裂面的形态具有明显的韧性断裂特征。     

原位聚合液晶环氧改性环氧树脂的研究

研究了原位聚合PHBHQ对环氧树脂的改性作用，结果表明，随着PHBHQ含量的增加，环氧树脂的冲击强度明显得到提高，而其他性能也不同程度的改善，并采用SEM分析了PHBHQ／CYD－128复合体系的微观结构。     

改性木纤维对LDPE和木纤维复合材料力学性能的影响

研究了用改性钛酸酯类偶联剂ＴＣ－ＰＯＴ、ＴＣ－ＰＢＴ处理木纤维和接枝氰乙基改性未纤维对低密度聚乙烯（ＬＤＰＥ）／木纤维复合力学性能的影响,用改性钛酸酯类偶联剂处理木纤维可提高复合材料的拉伸强度、但大大降低了复合材料的拉伸断裂伸长率。而且接枝改性方法处理木纤维在使复合材料提高拉伸强度的同时,保持了较高的拉伸断裂伸长率。     

反应型液晶聚合物与环氧树脂固化及力学性能研究

通过红外光谱（FT-IR），力学性能分析，研究了固化剂，固化温度，固化程度，液晶化合物种类，反应型液晶化合物的含量对环氧树脂/固化剂/液晶化合物体系固化反应程度及固化物力学性能的影响。结果表明，末端含有活性反应基团的热致性液晶聚合物（LCPU）和液晶性化合物（LCEU）对环氧树脂有明显的增韧增强作用。同时具有促进固化反应，提高反应速率的作用。LCPU的含量对环氧固化物的力学性能亦有较大影响。     

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.……     

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.     

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