SiO2气凝胶薄膜中Eu3+离子的跃迁

利用溶胶－凝胶法制得了Ｅｕ＾２＋掺杂ＳｉＯ２气凝胶薄膜,并对其发光及跃迁性质进行了研究。使用原子力显微镜对样品的型貌结构做了观测、采用ＸＲＤ和ＩＯＲ对所得样品的结构进行了研究,测量了样品的激发一发光谱、吸收光谱和时间分辨光谱。通过Ｊｕｄｄ－Ｏｆｅｌｔ理论计算了Ｅｕ＾３＋的＾Ｄ０的辐射跃迁几率,并根据时间分辨光谱研究了＾５Ｄ１的无辐射跃迁几率及弛豫性质。虽然结果与掺Ｅｕ＾３＋的体硅玻璃没有很大差别,     

长余辉光致发光玻璃的制备及其性能研究

利用陶瓷制备方法合成了ＳｒＡｌ２Ｏ４：Ｅｕ,Ｄｙ长余辉发光粉体,该磷光体主发射波长位于５２０ｎｍ,余辉时间长达８ｈ以上,并以硼硅酸盐低熔点玻璃为底材,掺杂该发光粉体,在一定温度下烧成,制得长余辉发光玻璃。     

新型光致发光储能材料的制备及其光学性能的研究

研究了一种新型的光致发光储能材料ＳｒＡｌ２Ｏ４∶Ｅｕ,Ｄｙ的合成方法,首先利用软化学法制备出了该发光材料的前驱体ＳｒＣＯ３－Ａｌ２Ｏ３－ＲＥ（ＯＨ）３超细粉体,解决了固相混合中存在的纷分不均匀性。然后将此前驱体粉体在还原气氛下高温烧结,最终制得亮度高、余辉时间长的超细发光粉体材料。并对其发光性能进行了研究,发光粉体的发射光谱表明,通过软化学法工艺制备出的发光粉体,其发射光谱的主峰位置较固相法兰移了１２ｎｍ。     

（Y,Zn,Sr）3（P,VO4）：Eu^3＋,Bi^3＋发光性质的研究

合成了组成为（Ｙ，Ｚｎ，Ｓｒ）３（Ｐ，ＶＯ４）：Ｅｕ＾３＋，Ｂｉ＾３＋的荧光材料，经Ｘ射线结构分析确定为Ｚｎ３（ＰＯ４）２结构，属于单斜晶系，空间群为Ｐ２１／ｎ。讨论了基质组成对Ｅｕ＾３＋离子发光性质的影响，用Ｙ＾３＋取代了一部分Ｚｎ＾２＋；用ＶＯ４取代了一部分ＰＯ４由于基质的４３６ｎｍ发射与Ｅｕ＾３＋的激发态能级的能量重叠，Ｅｕ＾３＋产生较强的５９８ｎｍ和６１８ｎｍ发射。另外，掺入少量Ｂｉ＾３＋     

离子束辅助沉积MoS2复合膜的XPS和ESR特性分析

通过ＩＢＡＤ技术制备了ＭｏＳ２＋Ａｇ（Ｃｕ）复合膜,并利用ＸＰＳ和ＥＳＲ考察了复合膜的氧化情况。发现在ＲＨ为６０％的大气环境下,Ｃｕ的掺入加速了ＭｏＳ２的氧化,相反Ａｇ的加入却使ＭｏＳ２的氧化受到抑制;ＸＰＳ发现ＭｏＳ２＋Ｃｕ复合膜中存在Ｍｏ＾６＋,ＥＳＲ却并没有发现中间态Ｍｏ＾５＋;而ＸＰＳ没有检测到ＭｏＳ２＋Ａｇ膜中有Ｍｏ＾６＋,ＥＳＲ却发现Ｍｏ＾５＋。这说明Ｍｏ＾５＋受化学环境影响较大。     

铜铬复合氧化物纳米粉的制备与表征

报道了自创铜氨铬合物溶液沉淀法（简称络合法）制备铜铬复合氧化物纳米粉的方法,并采用化学分析、ＢＥＴ比表面积测定、ＸＲＤ、ＸＰＳ、ＳＥＭ和ＴＥＭ等对该纳米粉进行了表征。结果表明,采用铜氨络合物溶液沉淀法制备的铜铬复合氧化物钠米粉的比表面积高达９６．６ｍ＾２／ｇ;样品中权有ＣｕＯ和ＣｕＣｒＯ２微晶,无尖晶石型的ＣｕＣｒ２Ｏ４晶粒;Ｃｕ只以Ｃｕ＾＋和Ｃｕ＾２＋状态存在,Ｃｒ只以Ｃｒ＾３＋状态存在;样品的     

烧成条件对长余辉蓄光玻璃光学性能的影响

以ＳｒＡｌ_２Ｏ_４：Ｅｕ,Ｄｙ长余辉发光粉体和低熔点硼硅酸盐玻璃为原料,在一定条件下合成了长余辉蓄光玻璃．研究结果表明,烧成温度和保温时间对该玻璃的发光效果影响较大．温度越高,保温时间越长,由于空气的氧化作用,蓄光玻璃的发光效果越差,本试验控制烧成温度在７５０～８００℃间,保温时间在 １０ｍｉｎ以内,能合成性能较好的蓄光玻璃．余辉衰减曲线表明蓄光玻璃的发光性能较之原始发光粉体有所下降．ＳＥＭ分析表明,低温合成的蓄光玻璃中,所含能继续保持发光性质的粉体料,明显比高温合成样要多．     

高温高压合成的硅酸锶有铕铋的发光特性

用高温高压方法合成了Ｓｒ２ＳｉＯ４Ｅ＾３＋ｕ，Ｂｉ＾３＋和ＳｒＳｉＯ３Ｅｕ＾３＋＿，Ｂｉ＾３＋，研究了合成压力对其发光性能的影响，与用溶胶－凝胶共沉淀法和常压高温法合成的产品作比较，常压制备的ＳｒＳｉＯ３Ｅｕ＾３＋，Ｂｉ＾３＋为六角结构，而在２．３４－４．１０ＧＰａ的合成压力范围内，它转变为赝正交结构；常压下Ｓｒ２ＳｉＯ４；Ｅｕ＾３＋，Ｂｉ＾３＋，为单斜结构，在４．２ＧＰａ的合成压力下，未发现其结     

发光陶瓷釉面砖的研制

文章介绍了一种新型的以ＳｒＡｌ２Ｏ４：Ｅｕ＾２＋Ｄｙ＾３＋为发光材料的发光陶瓷釉面砖及其制备工艺。产品的性能满足国家ＧＢ／Ｔ４１００－９２标准，发光釉面砖在暗的环境中８小时内能起到明显的标识作用。     

长余辉蓄光陶瓷SrAl2O4：Eu,Dy的性能及发光机理

制备了ＳｒＡｌ２Ｏ４：Ｅｕ,Ｄｙ材料。并测得其激光发谱,发射光谱和衰减曲线,首次报道了Ｄｙ的含量与荧光亮度和持续时间的关系,并对ＳｒＡｌ２Ｏ４：Ｅｕ,Ｄｙ系统的发光机理进行了解释。     

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 ...