海洋二号卫星微波辐射计系统设计

海洋二号(HY-2A)卫星是我国首颗海洋动力环境卫星,微波辐射计是该星的4个微波载荷之一,主要用于测量全球海洋表面温度、海面风速、海洋上空水汽和降雨等参数。HY-2A微波辐射计采用圆锥扫描方式,使用冷空反射器和星载热定标源完成在轨两点定标,覆盖频率范围为6~37 GHz,本文对系统、天线、接收通道和配平设计进行了介绍。     

海洋二号卫星主被动微波遥感探测技术研究

介绍了海洋二号(HY-2A)卫星4个微波有效载荷(雷达高度计、微波散射计、扫描微波辐射计和校正微波辐射计)的功能、性能和设计指标。HY-2A卫星突破了我国微波遥感设备技术上的瓶颈,为海洋环境监测预报业务化和防灾减灾提供了必要的海洋观测手段,解决了我国自主海洋动力环境参数遥感观测有无的问题。HY-2A卫星的成功发射和业务化运行为我国海洋卫星发展规划打下了坚实的基础。     

HY-2A微波散射计风场反演算法

本文针对我国首颗自主发射的海洋二号(HY-2A)卫星微波散射计,建立了业务化运行的风场反演算法,该算法将散射计海面风矢量反演分为粗搜索和精搜索两个步骤,有效地提高了运算效率。采用矢量圆中数滤波算法进行风向模糊解去除,并采用NCEP风场作为背景场对初始场进行选择,提高了模糊去除准确性。算法的反演结果经与NDBC对比和ASCAT风场星星对比验证,结果表明HY-2A卫星微波散射计可提供风速精度优于2 m/s或10%,风向精度优于±20°的海面风场观测产品,可满足海洋科学研究和海洋业务应用的需求。     

海洋二号卫星精密定轨方案设计及实现

2011年8月16日发射的海洋环境动力(海洋二号)卫星是中国第一颗动力环境卫星,其中搭载的雷达高度计需要连续的厘米级海洋地形测量,轨道误差在雷达高度计整体误差预算中占主要部分,为实现海洋二号卫星精密定轨事后处理径向10 cm精度的研制总要求,海洋二号卫星搭载了多普勒地球轨道和无线电定位系统(DORIS)接收机、双频全球定位系统(GPS)接收机和激光反射棱镜阵列用于精密定轨。本文综述了海洋二号卫星精密定轨方案设计和关键技术,给出了在轨测试结果。     

海洋二号卫星微波散射计系统设计与应用

海洋二号卫星是我国第一颗海洋动力环境卫星,于2011年8月16日成功发射,搭载的微波散射计是我国第一颗星载海洋风场测量雷达。海洋二号卫星微波散射计采用笔形波束体制,圆锥扫描工作方式,本文给出了微波散射计系统组成、主要性能指标和在轨数据预处理方法,并给出了在轨测试结果及在台风监测中的应用。     

高景一号卫星整装待发 我国将首次进入0.5米级商业遥感市场

<正>近期,在太原卫星发射中心,我国首颗0.5米级高分辨率商业遥感卫星高景一号各项发射场准备工作正有条不紊地开展。高景一号由2颗0.5米分辨率的光学小卫星组成,在轨应用后,将打破我国0.5米级商业遥感数据被国外垄断的现状,也标志着国产商业     

海洋二号卫星扫描辐射计海洋参数反演算法研究

针对海洋二号(HY-2)卫星扫描辐射计,利用辐射传射方程模拟,建立了海面温度、海面风速、大气水汽含量、大气液态水含量和雨率的反演算法,并利用扫描辐射计在轨数据对上述参数进行反演。经过对反演的海面温度和风速全球产品的真实性检验表明,算法合理可行,能够反演大气海洋参数,反演精度满足设计指标需求。目前,其他参数的反演产品的检验还在进行,而且反演算法还要根据对辐射计测量值定标的深入而进一步优化。     

HY－2卫星微波散射计海面风矢量场反演技术研究

主要针对HY-2卫星微波散射计,提出反演海面风矢量模型算法,并进行误差精度分析,给出了HY-2卫星微波散射计数据获取、预处理、风矢量场反演和产品制作技术流程,为HY-2卫星发射上天后能尽快发挥应有的效益做好技术准备,以此推动我国海洋微波遥感技术的发展.     

HY-2卫星微波散射计在西北太平洋台风监测中的应用研究

本文在简述海洋二号(HY-2)卫星微波散射计工作机制及海面风场反演原理的基础上,针对HY-2卫星微波散射计在轨运行的数据,利用该散射计数据开展海面台风中心定位、结构、台风路径、风速等值线、大风半径等台风参数的定量化应用分析研究。同时将HY-2卫星观测到的海面风场与风云二号(FY-2E)卫星云图进行融合展示,并将HY-2海面风场与ASCAT反演的海面风场和浮标提供的观测数据进行对比验证,多方面的定量分析显示出HY-2卫星海面风场观测的有效性和在台风监测中的优势。最后,对HY-2卫星微波散射计的优缺点进行分析,展望了其可能的改进方向。     

基于亚马逊热带雨林的HY-2卫星微波散射计在轨测量性能分析

中国第一颗自主海洋动力环境卫星海洋二号(HY-2)卫星于2011年8月16日成功发射,其上搭载的Ku波段微波散射计可以提供海面风矢量信息。根据国际上对已发射星载微波散射计在亚马逊热带雨林的研究结果:散射计在该地理区域观测的后向散射系数随季节的变化在0.15 dB以内。本文对HY-2微波散射计2012—2013年的亚马逊热带雨林区域的观测数据进行了分析,结果表明HY-2卫星散射计在轨运行两年来的测量性能很稳定,其在亚马逊热带雨林的季节性变化特征与国际上的研究结果一致。     

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...     

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.     

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.     

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.     

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.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.