绿色材料伪装性能检测技术分析

绿色材料是一种重要的伪装材料。伪装上不仅要求绿色材料的颜色与绿色植物近似，而且要求其近红外反射特性与绿色植物近似。伪装绿色检验镜是一种检验绿色颜料与植物绿色异谱程度的器材，论文提出了伪装绿色检验镜镜片的光谱透射特性要求，分析了其检色原理和检色效果，为绿色材料近红外伪装性能的检验提供了一种简便可行的方法。     

无卤阻燃剂的复配对EVA保温材料阻燃性能的影响

在弹性乙烯醋酸乙烯酯共聚物(EVA)发泡体系中,添加氢氧化镁(MH)、氢氧化铝(ATH)、红磷3种无卤阻燃剂,研究它们对体系阻燃性能的影响。结果表明,MH、ATH和红磷单独添加均可以不同程度改善EVA发泡体系的阻燃性,但仍较差。MH、ATH和红磷3种阻燃剂复配添加可以大大提高EVA发泡体系的阻燃性能。当MH和ATH添加量分别为32.1%和10.7%,红磷的添加量为5%时,阻燃性能最好,制备的无卤阻燃保温材料的导热系数为0.079W/(m·K),极限氧指数值(LOI)为34.5%,垂直燃烧性能为V-0级,水平燃烧性能为HB级,满足防火材料B1级的要求,同时解决了保温发泡材料的脆性问题。     

无卤阻燃剂的添加量对EVA发泡材料发泡性能的影响

针对EVA无卤阻燃发泡体系,研究了氢氧化镁(MH)、氢氧化铝(ATH)和红磷3种阻燃剂对EVA体系发泡性能的影响。结果表明:添加MH、ATH会使体系的粘度、发泡压力提高,交联度下降,过量的MH和ATH会导致发泡材料表面鼓泡,发泡倍率降低。添加红磷,体系的粘度、交联度下降,发泡压力、发泡倍率增大。为了保证EVA材料的顺利发泡,MH、ATH单独使用时,添加量分别不超过55%和50%(质量分数),阻燃剂复配使用时,添加量不能超过50%(质量分数)。添加MH、ATH和红磷会影响EVA材料的发泡性能。     

颜料对低发射涂料红外辐射特性的影响

本文详细论述了应用于红外陷身涂层的金属颜料、着色颜料的研究现状，并对这些颜料的红外特性进行了讨论。讨论认为：金属颜料发射率一般较低，在金属颜料中，粒径50цm的漂浮型铝粉具有较好的红外性能；在着色颜料中，大多数着色颜料具有很高的发射率，不适宜热红外伪装涂料使用；掺杂半导体颜料制成的涂料性能优良，但目前还处于研制阶段，是今后颜料发展的一个方向。     

船舶用阻燃树脂基体复合材料研究进展

复合材料的阻燃性能限制了其在船舶结构中的应用，树脂基体复合材料阻燃性能的好坏主要取决于树脂本身的阻燃性能。作者分别对复合材料中常用的三类树脂基体进行了总结研究：乙烯基环氧树脂在船舶领域已得到了广泛应用，但在某些要求阻燃的场合，乙烯基环氧树脂的应用受限。工业界和学术界针对阻燃乙烯基环氧树脂开展了大量工作，通过加入含磷笼型聚倍半硅氧烷(POSS)阻燃剂，显著提高了其阻燃性能，耐热性能和力学性能也有所提高；酚醛树脂是一种具有高阻燃性能的树脂类别，采用多种浸渍工艺将其制备成玻璃纤维或碳纤维增强预浸料，经过模压或热压罐等工艺方式可制备出力学性能良好、阻燃性能优异的复合材料产品。采用发泡工艺制备玻璃纤维增强酚醛发泡复合材料，其在更加轻量化的同时，仍具有良好的力学性能和阻燃性能；邻苯二甲腈树脂同样具有优异的阻燃性能，玻璃纤维、碳纤维增强的邻苯二甲腈复合材料热释放速率满足美军MIL-STD-2031中潜艇材料测定标准，邻苯二甲腈玻璃纤维复合材料的烟密度也远低于常见树脂复合材料的。阻燃乙烯基环氧树脂、酚醛树脂和氰基树脂优异的阻燃性能和良好的力学性能使其在水面舰艇和潜艇部件上具有广阔的应用前景。     

NBR／PVC发泡与阻燃材料的研究进展

综述了最近十几年的丁腈橡胶（NBR）、聚氯乙烯（PVC）的发泡材料和阻燃材料的研究进展。分别对NBR／PVC发泡材料、NBR／PVC阻燃材料和NBR／PVC泡沫阻燃材料的研究进展进行了总结,并指出NBR／PVC泡沫弹性体的阻燃技术发展缓慢,未来发展空间很大,将会成为NBR／PVC的一个新的发展趋势,应该受到重视。     

再生聚乙烯回掺量对无卤阻燃保温泡沫材料性能的影响

将再生聚乙烯(RPE)与低密度聚乙烯(LDPE)共混改性,采用红磷和无卤阻燃PE母粒,利用二段发泡工艺进行发泡,制备无卤阻燃保温材料。研究了RPE回掺量对材料力学性能、阻燃性能、保温性能的影响,并进行了燃烧烟气成分分析。结果表明,掺入RPE,不仅可以降低成本,而且可以改善纯LDPE凝胶率低的问题,更容易采用二段发泡法,各项性能均有所改善。当RPE回掺量为50%时性能指标达到最佳:发泡倍率为32(体积倍率),氧指数为30,垂直燃烧速度13mm/min,吸水率为0.0016g/cm3,导热系数为0.017W/(m.K)。材料燃烧后,烟气主要成分为聚乙烯热裂解产物,表明聚乙烯泡沫材料在燃烧过程中与氧气的接触不好,未检测到二噁英等有毒气体。     

不同无卤阻燃复合体系对全水发泡聚氨酯泡沫结构与性能的影响

以聚磷酸铵(APP)为主阻燃剂,采用"一步法"工艺制备了环保高效的无卤阻燃全水发泡半硬质聚氨酯泡沫。通过旋转黏度计、扫描电子显微镜、氧指数测量仪、水平垂直燃烧仪、万能材料试验机研究了聚磷酸铵与氢氧化铝(AH)、甲基磷酸二甲酯(DP)的无卤阻燃复合体系对聚氨酯泡沫的发泡行为、结构与性能的影响及规律。研究表明,各无卤阻燃复合体系物料的黏度均随APP用量增加而增大,当APP用量大于30pphp时,黏度增幅变大,尤以添加AH的体系为最。各体系的氧指数均表现出随APP用量增加而增大的趋势,并在APP用量为60pphp时趋于相近值(26.7%),APP/DP体系只能达到垂直燃烧的V-2级别,而只添加APP和APP/AH体系均未达到垂直燃烧级别。只添加APP的体系和APP/AH体系在APP量较高时均因物料黏度大反应过热导致体系发泡不稳定出现内部缺陷,压缩性能下降。     

阻燃半硬质LDPE/EVA泡沫塑料的研究

研究了添加型卤素阻燃剂、Ｓｂ２Ｏ２、Ａｌ（ＯＨ）３复合体系对ＬＤＰＥ／ＥＶＡ共混发泡体系的阻燃性能,并对制品结构与性能影响较大的因素进行了研究分析和讨论。实验结果表明,采用上述阻剂的复合体系对ＬＤＰＥ／ＥＶＡ发泡体系有良好的阻燃效果。制备出了氧指数为３５．５％,垂直燃烧性能达到了ＵＬ９４Ｖ－０级的ＬＤＰＥ／ＥＶＡ泡沫塑料。     

首届Interfoam发泡材料展圆满闭幕

正亚太地区专业的发泡材料产业盛会——首届Interfoam发泡材料展日前在上海跨国采购中心成功举办,展会现场国内外知名品牌汇聚一堂,以全球化视角展现了发泡材料全产业链的新技术、新产品、新设备、创新应用以及未来趋势,携手同仁开创发泡材料新时代。发泡材料的独特性能,使其应用范围极其广泛,无论是轻量化、减震降噪、保温隔热、过滤等的需求,还是阻燃、防静电、电磁屏蔽以及特殊性能的要求,     

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 ...