用液相沉积法在铝酸锶荧光粉表面包覆SiO2和Al2O3复合膜

铝酸锶是典型的长余辉发光材料,已经广泛应用于日常生活中,但是铝酸锶在水中极易发生水解,抗湿性差,严重限制了其应用。采用化学气相沉积法和物理蒸汽沉积法在长余辉发光材料表面包覆膜,对设备要求高,价格贵,不易推广。因此,采用液相沉积法在长余辉荧光粉铝酸锶表面包覆SiO2膜和A l2O3膜来提高其耐水性能,采用电镜扫描(SEM)、X射线衍射(XRD)表征膜的存在,并对包膜试样进行了耐水性和发光性能的测试。结果表明:铝酸锶荧光粉包覆了致密的复合膜层后,耐水性得到显著的提高,同时,包膜对荧光粉的发光性能影响较小,发射光和激发光强度损失均在10%以下。     

铝酸锶荧光竹塑复合材料的制备及性能研究

以高密度聚乙烯(HDPE)、竹粉、铝酸锶荧光粉和马来酸酐接枝聚乙烯(MAPE)为原料,通过密炼和注塑制备得到铝酸锶荧光竹塑复合材料。利用紫外-可见光分光光度计、荧光分光光度计、电子万能试验机、摆锤冲击仪和热重分析仪表征了铝酸锶荧光粉对复合材料的荧光性能、力学性能和热稳定性的影响,利用场发射扫描电子显微镜(FESEM)对铝酸锶荧光竹塑复合材料的拉伸断面的形貌进行观察。结果表明,随着铝酸锶荧光粉含量的增加,铝酸锶荧光竹塑复合材料的发光强度先增大后减小再增大,其弯曲强度、弯曲模量、拉伸强度和冲击强度均先增大后减小;场发射扫描电镜显示,随着铝酸锶荧光粉含量的增大,铝酸锶荧光粉在复合材料基体中的分散性变差,团聚增多,界面结合变差;热失重(TG)曲线和一阶微分(DTG)曲线分析表明,铝酸锶荧光竹塑复合材料的热失重为双阶失重过程,第一阶段为竹粉热降解阶段,第二阶段为基体HDPE热降解阶段,随着铝酸锶荧光粉含量的增加,铝酸锶荧光竹塑复合材料的热稳定性增强。     

光转换剂/Sr_4Al_(14)O_(25)红色荧光粉的制备与表征

采用硅烷偶联剂将一种氧蒽结构的光转换剂结合到Sr_4Al_(14)O_(25)∶Eu~(2+),Dy~(3+)荧光粉表面,铝酸锶能够储存光能并发出蓝绿光,光转换剂将铝酸锶发出的蓝绿光转换成红光,因此得到光转换剂/铝酸锶红色发光材料。利用扫描电镜、分光光度计、余辉亮度仪和辐射光谱分析仪对红色荧光粉的形貌和发光性能进行了分析与表征。结果表明:光转换剂成功地结合在Sr_4Al_(14)O_(25)的表面,当光转换剂浓度为5%,硅烷偶联剂浓度为1.25%时,红色荧光粉有301、350和539nm 3个激发峰,主发射峰位于601nm,此时所制样品的初始余辉为0.7084cd/m~2,色坐标为(0.5925,0.3605),色纯度为0.9095;探究了光转换剂和偶联剂浓度对样品发光性能的影响,当光转换剂浓度为5%,硅烷偶联剂浓度为1.25%时,样品既能保证较高的色纯度也具有优异的余辉性能。     

夜光有机玻璃

本项目将“铝酸锶,铕,镝”夜光材料与有机玻璃相结合,开发成功夜光有机玻璃。夜光有机玻璃可以充分发挥“铝酸锶：铕,镝”夜光材料的发光性能,在受光十分钟后,即可在暗处连续发光十小时以上。其产品夜光有机玻璃具有发光亮度高、不怕潮湿水气、表面平滑、外形美观、发光材料分布均匀、使用方便、容易加工等优点,从而为“铝酸锶：铕,镝”夜光材料的大规模实用化提供了有力条件。     

夜光有机玻璃

项目简介:本项目将“铝酸锶,铕,镝“夜光材料与有机玻璃相结合,开发成功夜光有机玻璃。夜光有机玻璃可以充分发挥“铝酸锶:铕,镝“夜光材料的发光性能,在受光十分钟后,即可在暗处连续发光十小时以上。其产品夜光有机玻璃具有发光亮度高、     

不同结构稀土掺杂铝酸锶的合成与发光性能研究

采用燃烧法成功合成了稀土掺杂铝酸锶长余辉发光材料.XRD结果表明,当铝锶n(Al)∶n(Sr)=2时,发光基质中只存在SrAl2O4相结构.随着Al∶Sr比值的增大,出现新相Sr4Al14O25.当Al∶Sr比值增大到4时, SrAl12O19相开始形成.而Al∶Sr比值增大到12时,全部为SrAl12O19相.光致发光测量结果表明,发光样品SrAl2O4∶Eu2 ,Dy3 发射谱峰值位于519nm,而发光样品SrAl12O19∶Eu2 ,Dy3 的发射峰位于512nm.余辉检测结果表明,不同结构铝酸锶发光样品的衰减都是由初始的快衰减过程和其后的慢衰减过程组成,但是不同结构铝酸锶发光样品的初始亮度和发光衰减快慢不同.     

夜光有机玻璃

本项目将“铝酸锶,铕,镝”夜光材料与有机玻璃相结合,开发成功夜光有机玻璃。夜光有机玻璃可以充分发挥“铝酸锶：铕,镝”夜光材料的发光性能,在受光十分钟后,即可在暗处连续发光十小时以上。其产品夜光有机玻璃具有发光亮度高、不怕潮湿水气、表面平滑、外形美观、发光材料分布均匀、使用方便、容易加工等优点,从而为“铝酸锶：铕,镝”夜光材料的大规模实用化提供了有力条件。夜光有机玻璃的表面光洁度与一般有机玻璃完全一样。     

夜光有机玻璃

本项目将“铝酸锶,铕,镝”夜光材料与有机玻璃相结合,开发成功夜光有机玻璃。夜光有机玻璃可以充分发挥“铝酸锶：铕,镝”夜光材料的发光性能,在受光十分钟后,即可在暗处连续发光十小时以上。其产品夜光有机玻璃具有发光亮度高、不怕潮湿水气、表面平滑、外形美观、发光材料分布均匀、使用方便、容易加工等优点,     

夜光有机玻璃

本项目将“铝酸锶,铕,镝”夜光材料与有机玻璃相结合,开发成功夜光有机玻璃。夜光有机玻璃可以充分发挥“铝酸锶：铕,镝”夜光材料的发光性能,在受光十分钟后,即可在暗处连续发光十小时以上。其产品夜光有机玻璃具有发光亮度高、不怕潮湿水气、表面平滑、外形美观、发光材料分布均匀、使用方便、容易加工等优点,     

夜光有机玻璃

项目简介：本项目将“铝酸锶,铕,镝”夜光材料与有机玻璃相结合,开发成功夜光有机玻璃。夜光有机玻璃可以充分发挥“铝酸锶：铕,镝”夜光材料的发光性能,在受光十分钟后,即可在暗处连续发光十小时以上。     

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 ...