不同异氰酸酯固化的蓖麻油／酚氧树脂聚氨酯的动态？…

４，４－二羟基二苯丙烷与环氧氯丙烷在ＢＦ３．ＯＥｔ２催化剂作用下，反应生成端羟基酚氧树脂，与蓖麻油混合，用３种异氰酸酯作固化剂，制得一系列交联聚氨酯，研究了这３种聚氨酯的动态力学性能。     

烯丙基酚氧树脂改性BMI的研究

介绍３种烯丙基酚氧树脂改性ＢＭＩ体系，详细研究了这些体系的溶解性，反应性，耐热性，结果表明，烯丙基酚氧树脂／Ｏ，Ｏ‘－二烯丙基双酚Ａ／ＢＭＩ体系具有良好的反应性；预聚物可溶于普通溶剂丙酮中，固化物具有良好的韧性和耐热性，其ＨＤＴ〉２８０℃，Ｔｇ〉３００℃，冲埚强度大于１５ｋＪ／ｍ＾２。     

紫外线固化水性聚氨酯丙烯酸树脂的研究

本文合成了由ＴＤＩ、ＰＰＯ２１０／２２０、ＤＭＰＡ和ＨＥＡ组成的紫外线（ＵＶ）固化水性聚氨酯丙烯酸树脂。探讨了树脂结构、固体分、烘干、中和剂、中和程度等对树脂水溶性能及感光性能的影响。     

二胺改性BPDA－ODA型聚酰亚胺的H_2／N_2分离性能

本文合成了一系列二胺改性的ＢＰＤＡ－ＯＤＡ型共聚酰亚胺膜，改性聚酰亚胺与未改性的ＢＰＤＡ－ＯＤＡ相比，透气性得到了明显的改善，改善的程度与第二种二胺单体的结构和用量有关。３０℃时，在ＢＰＤＡ－ＯＤＡ中加入２０ｍｏｌ％三甲基间苯二胺（３ＭＰＤＡ）或四甲基对苯二胺（４ＭＰＤＡ）时，共聚酰亚胺ＢＰＤＡ－ＯＤＡ／３ＭＰＤＡ（８０／２０）或ＢＰＤＡ－ＯＤＡ／４ＭＰＤＡ（８０／２０）的透Ｈ２系数和Ｈ２／Ｎ２分离系数分别大于６．５ｂａｒｒｅｒ和１６０，是比较好的气体分离膜材料。     

二胺改性BPDA—ODA型聚酰亚胺的H2／N2分离性能

本文合成了一系列二胺改性的ＢＰＤＡ－ＯＤＡ型共聚酰亚胺膜，改性聚酰亚胺与未改性的ＢＰＤＡ－ＯＤＡ相比，透气性得到了明显的改善，改善的程度与第二种二胺单体的结构和用量有关。３０℃时，在ＢＰＤＡ－ＯＤＡ中加入２０ｍｏｌ％三甲基间苯二胺（３ＭＰＤＡ）或四甲基对苯二胺（４ＭＰＤＡ）时，共聚酰亚胺ＢＰＤＡ－ＯＤＡ／３ＭＰＤＡ（８０／２０）或ＢＰＤＡ－ＯＤＡ／４ＭＰＤＡ（８０／２０）的透Ｈ２系数和Ｈ２／Ｎ２分     

聚羟基丁酸酯-羟基戊酸酯共聚物/明胶微粒的构造形态 …EI

以生物可降解材料聚羟基丁酸酯－羟基戊酸酯共聚物（ＰＨＢＶ）与天然明胶（Ｇｅｌ）为基材，以安定（ＤＺＰ）原药力模药，分别采用Ｏ／Ｗ、Ｗ／Ｏ／Ｗ、Ｏ／Ｗ／Ｏ，单乳化与双乳化溶剂蒸发法技术，制得３种不同结构形态微粒（微球与微囊），微粒平均粒径为３０～４０ｕｍ；探讨几种制备参数对微粒内、外部形态结构的影响；用扫描电镜观察了３种类型微粒内部与外部不同结构形态；测试了３种类型微粒释药性能，分析了微粒结构形态对     

丙烯酸酯共聚物无皂水性涂料室温固化的研究 (Ⅲ)水溶胶/HDI齐聚物固化过程的机理

丙烯酸酯共聚物水溶胶／ＨＤＩ齐聚物室温固化体系的固化过程认为是：共聚物侧链上的羟基和ＨＤＩ齐聚物上的ＮＣＯ基团进行反应，形成交联网络。抽提法和ＤＳＣ研究了影响固化度的因素，固化度随固化剂用量增多而增大，当超过３３％时，固化度趋于稳定。ＴＥＭ观察到，水溶胶／ＨＤＩ齐聚物的混合体系在微观上呈球状粒子形态，随着固化时间的延长，粒子边界变得模糊，成为无明显相分离的平面。化学分析法测定了固化过程中ＮＣＯ含量随时间的变化，在固化反应的开始阶段ＮＣＯ消耗较快，随后变得较为平缓。     

丙烯酸酯共聚物无皂水性涂料室温固化的研究：（Ⅲ）水溶？…

丙烯酸酯聚物水溶胶／ＨＤＩ齐取物室温固化体系的固化过程认为是：共聚珠铡链上的羟基和ＨＤＩ齐聚物的ＮＣＯ基团进行反应，形成交联网络。抽提法和ＤＳＣ研究影响固化度的因素，固化度随固化剂用量增多而增大，当超过３３％时，固化度趋于稳定。ＴＥＭ观察到，水溶胶／ＨＤＩ齐聚物的混合体系在微观上呈球状粒子形态，随着固化时间的延长，粒子边界变得模糊，成为无明显相分离的平面。化学分析法测定了因化过程中ＮＣＯ含量随时间     

大气中金属阴极保护用β-Al2O3粉体材料的制备与性质

研究了β－ＡＩ２Ｏ３粉体材料的制备工艺与性质迪种粉体材料可以采用慢速升温、分阶段保温的工艺,煅烧Ｌｉ２ＣＯ３、Ｎａ２ＣＯ３、ＡＩ２Ｏ３的均匀混合物不经球直接制得,根据使用要求与生产５条件,混合物可用干混、兰湿混－过筛或喷雾干燥法来制备、粉体材料主要由β／β＂－ＡＩ２Ｏ３组成,β＂相的相对含量〉７０％,加入适当的粘结剂与溶剂,可将其制臧在气环境中金属管道外的固体电解质涂层,涂层中粉体的化学与电化学性     

SPU型和FPU型耐候涂料

SPU型涂料是通过有机硅树脂改性脂肪族丙烯酸聚氨酯树脂而制得，即将有机硅树脂耐候优异性与脂肪族丙烯酸聚氨酯树脂附着力好的性能结合，充分发挥各自的优点。FPU型涂料是用脂肪族丙烯酸聚氨酯树脂改性有机氟树脂而制得，采用这两种树脂是为了降低成本而保持其耐候性损失不大。使涂料的性价比合理，便于推广应用。SPU型和     

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 ...