“1111”系铁基超导材料研究进展

简单介绍了"1111"体系铁基超导材料的发展历程及其与传统铜氧化物超导体的相似和不同;介绍了"1111"体系的晶体结构以及化学组成;详细综述了"1111"体系超导材料的制备技术——块材、线带材、薄膜的制备进展;最后展望了铁基超导材料的发展趋势——开发出实用化铁基超导材料的制备工艺,获得适合于低温高场条件下应用的线带材或铁基涂层导体。     

基于纺织材料的人造血管制备及应用进展

为了制备具有良好顺应性、安全性能高的纺织人造血管,从人造血管的研究背景、研究价值和发展历程出发,阐述了涤纶（PET）、聚氨酯(PU)、聚四氟乙烯(PTFE)和丝素蛋白(SF)等几种用于人造血管的主要材料的特点,阐述了机织、针织、编织、非织造及3D打印制备人造血管主要方法的特点、适用范围及最新研究进展,归纳了在人造血管领域目前现存的问题,最后对未来纺织材料在人造血管中的应用研究趋势进行了展望,以期为开发理想的人造血管提供一定的参考。     

农作物秸秆废弃物材料化利用现状及发展

目的针对各类材料制品原材料短缺的现状,探讨高效、清洁利用秸秆废弃物的资源方式。方法对造纸、发泡缓冲材料、人造板材、纳米纤维素、餐饮具及包装容器具等几大类材料进行分析与研究。结论秸秆材料化应用前景广阔,进一步技术创新解决关键性技术问题后有望迎来新的发展机遇;利用秸秆纤维制备纳米纤维素是新兴的高科技产业化发展方向。     

炭材料在医学领域的应用

包括碳纤维、石墨及其复合材料等在内的炭材料有着很好的生物相容性。综述了炭材料作为生物材料在医学方面的应用，介绍了部分炭材料医用制品如人造心脏瓣膜、生体修补膜、人造器官、医疗器械等的制备方法和优缺点。     

新型PST铁电薄膜的制备及其电性能研究

PST铁电薄膜是一种具有优良铁电、热释电和介电等性能的铁电材料.该材料在红外探测器、红外焦平面阵列、热成像器件、非易失性铁电存储器和大容量电容器等方面具有广泛的应用.PST铁电薄膜的制备方法多种多样,各具优缺点,不同的制备工艺对薄膜的性能有影响.叙述了PST铁电薄膜的制备技术、电性能和在热释电红外探测器方面的应用.     

我国人造金刚石用石墨材料的研究

石墨材料是人工合成金刚石的直接原料.回顾我国人造金刚石用石墨材料的发展历程,介绍目前金刚石工业专用石墨材料的种类、制备工艺及其相关性能.同时,概要介绍掺杂石墨和采用其他种类石墨材料合成金刚石的研究进展,并对今后人造金刚石用石墨材料的发展进行了展望.     

基于专利分析的石墨烯技术态势研究

在对石墨烯材料特性、制备、发展态势概述的基础上,以orbit专利数据库为数据源,通过对石墨烯专利申请量、技术领域、专利权人、专利地图和专利被引量等指标的定性分析,研究石墨烯产业的发展趋势、技术特点、主要竞争者和整体专利布局。采用定性与定量相结合,以事实性数据结合石墨烯产业的整体态势,分析目前的石墨烯技术难点和瓶颈问题,并提出建议。     

工业固体废弃物材料制作冷粘结人造轻骨料的研究进展

利用固体废弃物制作的冷粘结轻质骨料作为新型环保材料，满足资源再利用和节约能源、减少环境污染以及可持续发展战略的要求，是设计环保型混凝土的主要研究方向和推广方向。目前，提高绿色人造轻质骨料混凝土性能的重要手段之一就是克服人造轻骨料的缺陷，如吸水率大、坚固性差、孔洞多、干裂等。现有利用固废制备的人造轻骨料性能提升方式主要从造粒工艺、养护制度着手，如CO₂养护、烧结养护、挤压造粒等。同时通过调整固体废弃物材料种类、掺量也可以有效提升人造轻质骨料的性能。此外，借助不同的微观分析手段(如扫描电镜、水化热分析、热重分析、X射线分析等),并通过分析骨料力学性能、物理性能的影响因素，如化学组成、造粒设备参数等，也可以优化出有效提升人造骨料性能的方法，如纤维增强、碱性处理等。本文主要总结了工业固体废物的种类及造粒性能，综述了人造轻骨料的造粒方式、养护工艺、力学强度、物理性能和微观性能等研究进展，并指出了未来人造轻骨料的研究任务和完善方向。     

PZT铁电薄、厚膜及其制备技术研究进展

铁电薄、厚膜材料具有良好的铁电、压电、热释电、电光及非线性光学特性,在微电子学、光电子学、集成光学和微电子机械系统等领域有许多重要的应用.近年来,随着铁电薄、厚膜制备技术的发展,PZT厚膜材料及厚膜器件成为科学工作者研究的热点.介绍了PZT铁电薄、厚膜材料与器件的研究进展以及PZT铁电薄、厚膜制备技术及几种典型的PZT铁电薄、厚膜材料制备技术的特点,并指出了目前存在的一些问题和未来的发展方向.     

超材料的应用及制备技术研究进展

超材料是一类具有特殊性质、自然界中并不存在的人造材料。综述了单负超材料和左手超材料构型的研究进展和超材料在超分辨成像、电磁隐身和电磁吸波体等方面的应用。同时也对国内外主要超材料制备技术进行了分类和概述,包括电子束光刻、纳米压印技术和聚焦离子束技术等。最后对超材料的发展方向和应用方向进行了展望。     

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.……     

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.     

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...     

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 ...