微型节流制冷器最新应用

微型节流制冷器在红外夜视装备系统中占有十分重要的地位，本文介绍了用于红外焦平面探测器的微型节流制冷器的研制情况，产提出了微型节流制冷器在工程运用中所急需解决的几个关键技术。     

环境半导体β-FeSi2的研究进展

文章简要介绍了半导体β—FeSi2的基本性质及制备方法,讲述了β-FeSi2在太阳能电池、红外探测器和热电转换方面的应用,并对目前存在的问题及未来的研究动向做了简要的讨论。     

微透镜列阵与红外探测器列阵集成芯片的研究

在分析微透镜列阵光聚能原理的基础上,针对背照式256290铂硅红外焦平面探测器列阵 的结构参数,设计了衍射微透镜列阵,使入射光通过硅基底聚焦至探测器的各个光敏面上, 提高光能利用率从而增强探测能力。实验获得了微透镜列阵与红外焦平面集成芯片,并在热成像中取得了良好的结果。     

红外焦平面阵列盲元检测算法

为提高红外焦平面阵列盲元的定位精度,分析了盲元的产生机理,指出了探测器所处环境温度对探测元的探测能力以及焦平面阵列的盲元数量和位置分布的影响,提出了一种考虑环境温度差异的红外焦平面阵列盲元检测算法,精确定位了不同温度范围内的盲元位置.实验结果表明,该算法可将随环境温度改变而改变的盲元位置信息准确检测出来.     

提升红外焦平面探测器杜瓦组件的贮存寿命北大核心CSCD

杜瓦内真空度退化和芯片盲元增加是影响红外焦平面探测器杜瓦组件贮存寿命的两大方面。杜瓦组件的排气策略直接关系到红外红外探测器杜瓦的真空寿命和红外芯片的贮存寿命,是影响红外探测器杜瓦组件可靠性的关键。本文以杜瓦放气率测试技术为依托,结合杜瓦组件在贮存环境下的退化规律和模型预测杜瓦贮存寿命。最后,综合平衡排气温度/时间对杜瓦真空寿命及芯片盲元损耗的影响,提供一种实现红外芯片和杜瓦真空同时失效的技术途径。     

提升红外焦平面探测器杜瓦组件的贮存寿命

杜瓦内真空度退化和芯片盲元增加是影响红外焦平面探测器杜瓦组件贮存寿命的两大方面。杜瓦组件的排气策略直接关系到红外红外探测器杜瓦的真空寿命和红外芯片的贮存寿命,是影响红外探测器杜瓦组件可靠性的关键。本文以杜瓦放气率测试技术为依托,结合杜瓦组件在贮存环境下的退化规律和模型预测杜瓦贮存寿命。最后,综合平衡排气温度/时间对杜瓦真空寿命及芯片盲元损耗的影响,提供一种实现红外芯片和杜瓦真空同时失效的技术途径。     

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.     

红外探测器光谱响应率定标方法

采用新的方法对波长范围1-3μm的红外探测器绝对光谱响应率进行定标.红外探测器的光谱响应率定标是在两套定标系统上利用两种参考探测器实现的.首先在红外光谱比较系统上利用一个平响应的腔式热电堆探测器作为参考探测器,测量待测红外探测器相对于标准探测器的连续光谱响应率;然后在可见一近红外定标系统上,利用低温辐射计和激光器在几个单立波长上进行绝对光谱响应率测量.这样,通过计算就能得出待测红外探测器在每个波长上的绝对光谱响应率.采用上述方法对TS-76探测器进行光谱响应率定标,联合不确定度小于0.95%.     

多元红外三通道辐射制冷器研究

研制了一台用于冷却红外多光谱扫描仪中多元红外探测器列阵的星载辐射制冷器。空间红外遥感器需要制冷系统,而辐射制冷器非常适合空间遥感器的需求。简要介绍了它的研制情况,方案设计思路,辐射制冷器基本构成,理论计算方法,做过的模拟试验及其结果,并对在轨使用情况作了简介。     

微型节流制冷器降温时间的优化研究

本文介绍了一款高德红外快速制冷型的微型节流制冷器及对该制冷器从充气容积、杜瓦和翅片管换热器等方面的优化研究。使用优化的制冷器后,红外探测器焦平面的降温时间由18 s@100 K缩短至4.5 s@100 K,且校正后图像的非均匀性小于6 mV。     

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.     

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...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.