干涉雷达地表相干特性分析及土地类型分类

基于重轨干涉相干测量的基本原理，利用ERS－1／2重轨干涉雷达数据，对大部分地表有、无积雪覆盖时的地表的相干特性进行了分析，并在此基础上，利用地物的相干特性和振幅强度信息，对大部分地表夫积雪覆盖时的地表进行了土地类型的识别和分类。     

干涉SAR相干系数估计的快速算法

在SAR干涉测量中,相干系数是干涉图像对相位稳定性的衡量标准。干涉基线距和地表地形都影响相干系数的计算,在通常的相干系数的计算中,需要补偿由基线和地形引起的干涉相位,造成相干系数计算中计算量的大大增加。本文应用了一种不需要进行相位补偿的相干系数计算方法,并与通常的相干系数的计算方法相比较。实验结果证明,本算法在保证一定的相干系数计算精确性的基础上,大大提高了相干系数的计算效率,可以应用于快速浏览相干图像对,以评价其用于相干测量时的质量好坏。     

多光谱测温法建模方法的研究

本文提出一种新的多光谱测温法数学模型的建立方法－－基于参考温度的数学模型。大量的计算机仿真实验结果表明，此方法与现有的基于亮度温度的数学模型相比，其测量准确度得到了大大提高，实际应用起来也方便，是一种较实用的数学模型。     

一种新的外差干涉信号处理方法—相位及相位整数测量法

介绍了一种新的外差干涉信号处理方法－相位及相位整数测量法。用此方法不仅可使干涉测量的分辨率提高到λ／１０００－λ／２０００，而且扩大了测量范围，解决了大范围、动态测量位移的问题。文中还给出了用此方法进行信号处理的外差干涉仪测量压电陶瓷动态位移的实验结果。     

激光自混频干涉法测量表面粗糙度的理论分析

设计了一种半导体激光自混频干涉法测量表面粗糙度的实验，对半导体激光自混频干涉法测量表面粗糙度中的干涉效应进行了理论分析，推导了干涉信号与表面粗糙度的数学关系式，讨论了影响测量信号的因素。实验结果表明，随着加工表面粗糙度的降低，反射光的强度逐渐增加，被测物体表面的反射率越高，越有利于测量。     

全息照相干涉测量法在工程测量中的信息能力

全息照相干涉测量法在工程测量中的信息能力Ａ·Ｍ·全息照相干涉测量法的实质在于摄录、观察和判读两种干涉图，一是直接对目标摄录的，一是由全息照相再生的。全息照相乃是一种干涉图，由实物散射光波同与其相干的基准光波形成。全息照相（全息图）的实用价值是实物波能...     

低相干光源干涉特性的实验研究

目前很流行的低相干干涉(LCI)技术已被广泛的应用于高灵敏度的测量技术中,文章基于维纳-欣钦定理,推导出了低相干光源干涉特性的表达式并进行了详细理论研究,通过实验系统得到了与理论相一致的清晰干涉条纹。由于系统中噪声的存在,为了提高低相干干涉(LCI)测量技术的精度,满足实际中高精度测量的要求,利用功率谱估计的方法对实验测得数据进行FFT去噪处理,实现去除拍频噪声等无用信号。     

干涉条纹图估测基线的方法研究

根据SAR干涉测量原理，提出了利用干涉相干条纹估测基线的方法，并以欧洲空间局资源卫星1号和2号携带的SAR系统在中国新疆伽师试验区获取的串接式（Tan-dem）干涉测量数据为数据源，对提出的方法进行了验证，结果表明，该方法能有效地估测基线，并弥补不能有效获取卫星轨道参数时，对基线进行估测的缺陷，该方法尤其适用于差分干涉测量的研究。     

基于移相干涉技术的高精度活塞内径测量方法研究及测量系统研制

介绍了一种应用移相干涉法测量精密活塞内径的方法,并研制了高精度活塞内径测量仪.利用一等量块与平面平晶研合形成的标准具作为标准,采用白光干涉定位、激光干涉测长与移相干涉技术结合的位移测量技术方案实现了活塞内径的高精度非接触自动测量.实验结果表明,该仪器在(10～100)mm测量范围内,测量分辨率为1nm,测量结果的标准偏差不大于50nm.     

流体温度场测量中的电子散斑干涉技术

电子散斑干涉是一种利用全电子记录和计算机图象处理系统替代传统照相干版进行测量的先进技术。本文在简要介绍其应用于流体温度场测量的理论与实验的基础上,着重描述了如何通过调整光学系统参数配置来获取最佳质量原始干涉图象的途径,并给出对比分析结果。     

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.     

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.