基于导电纤维的柔性电子器件研究进展

柔性电子器件具有优异的灵活性,实现了与服装的无缝集成,在各种实际的可穿戴应用中具有巨大的潜力。一维纤维状电子器件由于其优异的柔韧性、可编织性及舒适性成为智能可穿戴领域的研究热点。首先,综述了用于纤维状柔性电子器件的一维可拉伸电极的研究进展,然后详细介绍了高性能一维纤维状柔性电子器件制备过程中具有代表性的导电材料、制造技术及一维柔性纤维进一步应用于各类电子器件的主要制备方法,另外总结了近年来基于柔性纤维状电子器件在智能可穿戴领域的应用。最后对一维纤维基智能可穿戴电子器件的机遇和挑战进行了批判性思考。      

磷酸四钙合成机理及其稳定性研究

本文讨论了直接固相反应法制备磷酸四钙的工艺过程,证明原料在煅烧过程中先生成了羟基磷灰石,接着在更高的温度由羟基磷灰石分解产生磷酸四钙.同时还发现磷酸四钙在潮湿和高温环境下均会转变为羟基磷灰石.     

人工肌肉纤维的研究进展

人工肌肉领域是一个高度跨学科的研究领域,在过去30年中发展迅速.人工肌肉是指一类材料在受到外部刺激如电压、电流、温度、压力、光线、湿度等产生响应,通过自身结构的变化而产生形变的材料,其在软体机器人、假肢、外骨骼及温度调节服等多种应用中具有非常重要的作用.人工肌肉根据其宏观表现形态一般可分为膜状和纤维状.纤维状人工肌肉可将外界刺激导致的体积膨胀通过其螺旋结构转换为纤维径向的转动和轴向的收缩,从而形成旋转驱动和伸缩驱动,其能量转换效率、功率密度以及做功都远高于现有的一些膜状驱动器.另外,纤维状人工肌肉不仅可以完成伸缩、转动等运动,还可通过并股和编织等方式实现更复杂的运动,因其力学性能优异、柔韧性好,且在形式上更接近自然生物肌肉,从而更具优势.人工肌肉纤维还可以以多种不同的形式进行驱动,包括温差驱动、溶剂/气体吸附或渗透驱动、电化学驱动以及气压驱动.近年来,基于柔性纤维状材料的人工肌肉的研究取得了很大的进展.人工高分子纤维(如尼龙线)、人工无机纤维(如碳纳米管纤维、石墨烯纤维等)、天然纤维(如蜘蛛丝、蚕丝等)因具有本征柔性的特征,在人工肌肉纤维的原材料上扮演着重要角色.本文综述了人工肌肉纤维的研究进展,分别对人工肌肉纤维的驱动材料、工作机制、驱动方式、评价参数及智能织物方面进行了总结,并在最后对人工肌肉纤维领域亟待解决的问题进行了分析与讨论.     

基质囊泡及其在骨矿化过程中的作用

基质囊泡(Matrix vesicles,MVs)是骨矿物初始形核生长的场所。骨矿化过程中,钙、磷酸根等离子经通道蛋白跨膜运输进入MVs内,当局部浓度达到一定值时,磷酸钙晶体开始沉积。磷酸钙的存在形态包括无定形磷酸钙、磷酸八钙及羟基磷灰石等。MVs可以调节细胞内外基质中的钙和磷酸根离子的稳态及无机磷酸盐/无机焦磷酸盐的比值,提供磷酸钙晶体成核位点,在骨矿化的初始启动过程中发挥重要作用。本文概述了MVs的生物来源、分子组分、提取方法,MVs介导的骨矿化过程,以及近年来利用囊泡作为体外矿化模型模拟MVs矿化过程的研究进展。     

磷灰石-硅灰石/β-磷酸三钙复合多孔支架材料的制备和表征

以磷灰石-硅灰石玻璃陶瓷(AW)粉和β-磷酸三钙(β-TCP)粉为原料. 以硬脂酸为致孔剂. 经模压成型、1170℃烧结制备磷灰石-硅灰石/β-磷酸三钙复合多孔支架材料(AW/βTCP). 采用X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、诱导耦合等离子体原子发射光谱(ICP-AES)等方法分析支架的晶相组成、显微结构、物理性能、生物活性和降解性. 将大鼠骨髓间充质干细胞(rMSCs)与支架体外复合培养评价支架的生物相容性. 结果表明: 所制备的AW/β-TCP支架材料的抗压强度达14.3MPa. 孔隙率达66.9%. 孔径为100～700μm. 具有良好的生物相容性、生物活性和降解性. 可作为骨组织工程支架的候选材料.     

区域熔炼结晶时Mo-Re合金单晶亚结构形成Ⅱ晶体碎化

俄罗斯学者介绍了工程结构合金Mo-47wt%Re单晶体区域熔炼结晶时亚结构形成的研究结果,先前的研究多注重单晶体树枝状晶胞形貌及其纵横向纤维结构不均匀性,而本实验中对熔区移动速度(V),结晶前沿形状对单晶内更粗大的嵌镶块大小和取向差的影响进行研究.研究中采用电子束区域熔炼制备了Mo-47wt%Re合金,直径为φ10mm～12mm,取向为[001]单晶体.     

火焰原子吸收法测定钙时磷酸盐的干扰机理研究

通过在钙标准溶液中添加不同浓度的磷酸盐,采用火焰原子吸收法测定钙吸光度的变化情况,探讨钙的原子化效率与待测元素(钙)浓度、干扰物浓度(磷酸根)和二者浓度比例之间的关系,得出火焰原子吸收分光光度法测定钙时磷酸盐的干扰机理是由于磷酸根与钙形成了难挥发的磷酸钙,导致钙在火焰中不能完全蒸发解离,其干扰程度随试样中待测元素钙的浓度变化而变化,并与待测元素钙的浓度和干扰物质磷酸根浓度的比例有关,且磷酸根对钙的干扰不仅影响工作曲线的斜率,而且还影响工作曲线的线性。     

微球法制备聚乳酸/β-磷酸三钙组织T程支架的研究

本文采用一种新颖的微球法制备了聚乳酸/β-磷酸三钙组织工程支架.并通过孔隙率的测定、电镜及抗压模量的测试来研究β-磷酸三钙的加入量以及搅拌时间对多孔支架的结构以及力学性能的影响.研究发现,对于同一组分的材料随着搅拌时间的增长,多孔支架的孔隙率有增大的趋势,同时多孔支架的抗压模量不断增大.随着β-磷酸三钙加入量的增加,多孔支架的孔隙率有先增大后减小的趋势.当在2 g聚乳酸中加入0.2 g β-磷酸三钙时孔隙率达最大.加入β-磷酸三钙后的多孔支架都不同程度比同样条件下纯聚乳酸多孔支架的抗压模量有所降低,但当加入0.2 g β-磷酸三钙后,以300转/分钟的速度搅拌2 h时,所制得的多孔支架的抗压模量与纯聚乳酸多孔支架的抗压模量基本相当.在2 g聚乳酸中加入0.2 g β-磷酸三钙,以300转/分钟的速度搅拌2 h时,材料具有较高的孔隙率(55.5%),同时也具有较高的抗压模量275 MPa,是较好的反应条件.     

生物陶瓷骨内植入后与组织间的界面研究

将β—TCP陶瓷植入大白兔的股骨内并定期注射四环素，分别在光学显微镜、荧光显微镜或扫描电子显微镜下观察新骨的形成和成骨过程，研究了β—TCP植入体内后与组织间的界面作用以及磷酸钙生物陶瓷的成骨作用．结果表明，在类骨质表面有大量的成骨细胞，间充质细胞增生和浸入．植入β-TCP陶瓷两个月后，类骨质通过钙化转变为编织骨．植入三个月后，出现由骨桥连接的“骨岛”，β—TCP陶瓷降解，并被新骨分散．植入六个月后，新的骨髓腔形成，编织骨变成板层骨．八个月后，在哈弗氏骨板上出现材料颗粒，形成典型的松质骨结构．因此，无生命的钙磷材料在体内可以参与有生命的组织活动．     

纤维状有机光电探测器制备与特性研究

纤维状光电探测器因具有柔性可编织、全角度光探测等特性，有望在可穿戴电子领域取得广泛应用。现已报道的纤维状光电探测器多采用无机光敏材料，器件存在机械柔性受限、制备工艺复杂等问题。本文提出制备纤维状有机光电探测器(FOPD)，采用浸渍提拉法依次在锌丝表面制备电子传输层(ZnO)、有机体异质结光敏层(PBDB-T:ITICTh)和空穴传输层(PEDOT:PSS)等功能层，最后缠绕银丝或碳纳米管纤维(CNT)作为外电极，制备了两种柔性FOPD。结果表明，两种器件在可见光波段均具有优良的响应，整流特性明显，在-0.5 V偏压下比探测率均可达10¹¹Jones (300 nm～760 nm)。其中，CNT外电极与光敏层的界面接触更佳，器件具有更低的暗电流密度(9.5×10^-8A cm^-2，-0.5 V)和更快的响应速度(上升、下降时间：0.88 ms、6.00 ms)。本文的研究有望为柔性纤维器件和可穿戴电子领域的发展提供新思路。     

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.……     

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.     

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.     

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