凹凸棒石/油菜秸秆木质陶瓷的制备及性能

为了资源化利用油菜秸秆等废弃物, 以油菜秸秆和凹凸棒石为原料, 以酚醛树脂为黏结剂, 通过复合、 热压、 烧结等工艺过程制备了凹凸棒石/油菜秸秆木质陶瓷。对不同原料质量配比和烧结温度下制备的复合材料进行性能测试。结果表明, 采用该工艺制备凹凸棒石/油菜秸秆木质陶瓷是可行的, 原料的选择、 质量配比、 烧结温度等参数对材料制备过程及性能均有较大的影响。油菜秸秆与凹凸棒石质量配比为1∶2时复合材料的力学性能较好, 烧结温度在600~700 ℃时, 残炭率最高; 在600~800 ℃范围内, 抗弯强度的提高达到最佳; 在800 ℃时, 导电性能得到改善。     

低温烧结细晶Y-TZP

通过在Ｙ－ＴＺＰ中加入适量的硅酸盐玻璃添加剂,使其烧结温度明显降低,并且制备出具有细晶粒、高强度的四方相氧化锆增韧陶瓷材料．分析了添加剂含量及烧结温度与材料致密度、显微结构及力学性能的关系,发现在Ｙ－ＴＺＰ材料中加入１ｗｔ％的添加剂,可以使材料在１４００℃下烧结,氧化锆晶粒尺寸约为１００～２００ｎｍ;其抗折强度可达９５０ＭＰａ．     

凹凸棒石/油菜秸秆木质陶瓷的制备及性能

为了资源化利用油菜秸秆等废弃物,以油菜秸秆和凹凸棒石为原料,以酚醛树脂为黏结剂,通过复合、热压、烧结等工艺过程制备了凹凸棒石/油菜秸秆木质陶瓷.对不同原料质量配比和烧结温度下制备的复合材料进行性能测试.结果表明,采用该工艺制备凹凸棒石/油菜秸秆木质陶瓷是可行的,原料的选择、质量配比、烧结温度等参数对材料制备过程及性能均有较大的影响.油菜秸秆与凹凸棒石质量配比为1:2时复合材料的力学性能较好,烧结温度在600～700℃时,残炭率最高;在600～800℃范围内,抗弯强度的提高达到最佳;在800℃时,导电性能得到改善.     

不同温度煅烧凹凸棒土的水化活性

研究了煅烧温度(200～800℃)对凹凸棒土外观、矿物组成和活性SiO2含量的影响,煅烧前后凹凸棒土对水泥浆体化学结合水量、反应程度和水泥胶砂抗折、抗压及劈裂强度等力学性能的影响.结果表明:煅烧温度改变了凹凸棒土的矿物组成,从而影响了水泥基材料的水化活性,经500℃煅烧的凹凸棒土对水泥基材料水化活性的提高效果最佳.     

硅烷偶联剂改性凹凸棒土的制备及其吸附Cr6+的性能研究

制备了KH-550改性凹凸棒土材料,研究其对Cr6+的吸附性能,并考察不同制备条件对改性凹凸棒土吸附Cr6+的影响。研究结果表明,用硅烷偶联剂KH-550改性剂用量为(酸改性凹凸棒土质量为6.0g)4.5mL、反应时间为2h、反应温度为40℃时,制备的改性凹凸棒土对Cr6+的吸附率最大,污水处理效果最佳。     

高温改性凹凸棒石对Cr(Ⅵ)的吸附研究

将凹凸棒石经低温煅烧改性,得到一种改性凹凸棒石材料,以提高凹凸棒石的吸附性能,通过BET(比表面积分析)和FT-IR(红外光谱仪)等实验技术及吸附含铬离子废水来袁征凹凸棒石的性能.实验结果表明高温改性可以提高凹凸棒石的比表面积及其吸附性能;当改性温度为350℃时,可以获得最大的比表面积为140.7m2/g.当凹凸棒石用量为10g/L、溶液pH为2,吸附时间为1h,去除率可以达到98％.     

正十八烷/凹凸棒土复合相变储能材料的制备及热性能研究

以正十八烷为相变材料,凹凸棒土为支撑基体,通过真空浸渍法将相变材料有效地吸附固定于凹凸棒土的孔道结构中,制备出结构稳定、热性能稳定的新型正十八烷/凹凸棒土复合相变储能材料。由凹凸棒土N2吸附试验和SEM图片可以发现凹凸棒土疏松多孔、比表面积大,从而能有效吸附正十八烷相变材料。对制备的新型复合相变储能材料进行DSC测试,并进一步对其进行20次DSC冷热循环测试,样品的相变温度及相变潜热基本保持不变,说明其具有优异的相变蓄热特性和热循环稳定性,具有较好的应用前景。     

凹凸棒石基碳复合陶粒的制备和特性研究

考察了物料配比和煅烧工艺对以凹凸棒石粘土、锯末(造孔剂)和水玻璃(粘结剂)为原料,在氮气保护气氛下煅烧制备凹凸棒石基碳复合陶粒性能的影响,利用复合陶粒的抗压强度、显气孔率优化材料配比和煅烧工艺,并通过XRD、SEM表征复合陶粒特性。结果表明凹凸棒石粘土、锯末、水玻璃的最佳质量配比为68∶20∶12,在最佳煅烧条件下(700℃),可以制备出满足国家标准的水处理用陶粒,浸泡实验表明凹凸棒石基碳复合陶粒具有优异的耐水性能;该材料有利于微生物的附着。     

基于高岭土增韧环氧树脂水泥基材料的多强度组合指标配比优化法

煅烧高岭土能有效改善环氧树脂水泥基材料的力学性能,实验表明：煅烧高岭土可大大提高环氧树脂水泥基材料的3 d早期抗折、抗压强度,当高岭土掺量为30%时,改性环氧树脂水泥基材料的抗折及抗压强度分别提高了134.28%、106.25%;当高岭土掺量小于30%时,改性环氧树脂水泥基材料具有二次抗折强度,且抗折强度残余率大于50%。根据不同高岭土掺量对改性环氧树脂水泥基材料抗压强度、抗折强度、二次抗折强度的影响规律,提出了适用于不同结构工程受力特点的多强度组合指标配比优化法,获得了考虑二次抗拉强度影响的不同最大拉应力和最大压应力组合条件下最优的高岭土配比,为实际不同结构体不同部位不同受力特征的高岭土改性环氧树脂水泥基材料制备提供了理论依据。     

凹凸棒土吸附相变储能复合材料制备及其热物理性能表征

基于凹凸棒土对有机物的良好吸附性能,以凹凸棒土为吸附介质、石蜡为吸附对象,制备有机/无机复合相变材料。由于有机相变材料被吸附到微孔中,使其相变在固定的空间内进行,从而避免了材料在液相状态下的流动和渗漏问题。试验结果显示,坡缕石占80%的凹凸棒土吸附石蜡的最优质量比为2∶1。DSC的测试显示,复合相变材料的焓变值与凹凸棒土和石蜡的吸附比例相关,凹凸棒土中坡缕石的含量越高,凹凸棒土的吸附能力就越强,复合相变材料的焓变值也就越大。温度循环试验的结果显示,复合相变材料具有良好的储(放)热性能,在环境温度上升和下降的过程中,能够储存和释放热量,这不仅增加了环境温度的惰性,也使能量能够在不同的时间和空间进行迁移,从而达到一定的节能效果。     

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.     

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 ...