基于动态滤波重采样的星载微波辐射计观测亮温方法

研究了星载微波计的亮温观测,针对目前常用的采用重采样的固定滤波方法不考虑观测几何变化的不足,开发了一种采用基于Backus-Gilbert (BG)方法的动态滤波重采样的亮温观测方法,该方法从卫星观测方式入手,考虑了观测几何沿经线方向和沿纬线方向的变化,采用线性插值的方法对滤波模板进行实时更新,实现了动态滤波重采样的目的.对该方法并进行了仿真试验和基于对地观测的先进扫描微波辐射计(AMSR-E)观测资料的真实数据试验,试验结果表明,这种方法的匹配误差小于固定滤波方法且具有较高的计算效率,具有良好的业务化应用潜力.     

有限观测下的结构损伤实时在线诊断

根据有限观测的结构动力响应,实时对结构发生损伤的时间、位置与损伤程度进行诊断,是目前土木工程健康监测的一个重要的任务。提出一种在对结构加速度部分观测的情况下,对结构刚度发生突变的结构损伤形式进行实时的追踪和诊断的算法。该算法的主要思想是首先基于扩展卡尔曼滤波识别结构刚度参数,然后通过观测加速度和计算预测的加速度误差平方和,对结构刚度发生突变时刻进行判断,再通过优化突变时的结构的刚度参数变化,对损伤位置与损伤程度进行识别。数值模拟和实验的结果都表明了,该方法能够有效地追踪时变参数,并实时诊断出损伤发生的时间、位置和程度。     

ASSM-Ⅱ型声学悬浮泥沙观测系统

本文介绍了一种新型的水文观测设备－“ＡＳＳＭ－Ⅱ型声学悬浮泥沙观测系统”，它可认自动，连续和长时间地实时观测水中悬浮泥沙深度分布和动态变化过程，文中介绍了工作原理框图，技术参数，性能特点及海上现场观测结果。     

乳化炸药受冲击载荷微结构特性变化的细观和动态观测

文章介绍一种研究乳化炸药冲击钝化机理的实验方法。利用电爆炸对乳化炸药进行冲击加载,通过显微摄影方法观测了炸药受冲击载荷后微结构的变化,对其受冲击钝化和拒爆原因进行了解释。用高速摄影进行实时记录组成一套对微结构变化进行动态观测的实验系统,通过实验发现受压钝化现象的时间特性。     

GPS RTK技术在公路勘测中的应用

<正>0引言RTK(Real Time Kinematic)技术又称载波相位差分技术,是实时处理两个测站载波相位观测的差分方法,它可使实时三维定位精度达厘米级,常规控制测量如三角测量,导线测量都要求点位间通视,费时费工,而且精度不均匀,外业中不能实时知道测量成果和观测精度。GPS静态快速静态相对定位测量能够进行各种高精度控制测量,它不需要点位间通视,但是需要进行数据后处理,不能进行实时定位并知道点位精度,若内业处     

海洋观测技术

通过海流测量技术的沿革等示例,浅谈了水声技术与海洋观测之间相互依赖相互促进的关系。表明了海洋观测技术在海洋活动中的基础地位,并概括归纳了它的技术特点。强调了传感器技术、观测平台技术和通讯技术在海洋观测技术中的作用。阐述了目前在海洋科学方面和海洋管理方面,海洋观测技术所面临的挑战,以及海洋观测技术向自动、实时、同步、长期连续观测和多平台集成、多尺度、高分辨率观测方向发展。形成从空间到海床,从沿岸到大洋的立体的网络化的发展趋势。     

一种基于子空间学习的实时目标跟踪算法

针对当前目标跟踪算法鲁棒性低且运算慢的问题,本文提出了一种基于子空间学习的实时目标跟踪算法。该方法在粒子滤波跟踪框架下,采用增量式PCA子空间学习方法学习一个正交子空间,利用学习到的正交子空间对目标外观进行线性表示;针对目标在遮挡、运动模糊等复杂干扰状态下容易产生跟踪漂移的问题,本文建立了一个将遮挡等复杂因素考虑在内的观测模型和模板更新方案,解决了基于最小均方误差准则的传统观测模型在复杂场景下的跟踪漂移问题。实验结果表明,本文的跟踪方法能够达到很高的跟踪精度,同时也达到了接近实时的跟踪速度。     

实时观察法在金属凝固中的研究进展

介绍了用于研究凝固过程的实时观察法的发展情况,同时综述了目前用于实时观察法研究的合金类型和现有的实验仪器和装置,分类探讨了类金属合金实时观测现象与金属合金实验结果的吻合程度,和对实际凝固实验中无法克服的困难的解决情况,并对国内外的发展情况和存在问题进行了分析和讨论.     

双材料界面粘接质量定量检测的相移错位散斑技术

用统计光学原理分析了错位散斑条纹的形成机理,并把相移技术引入错位散斑之中,使该方法不仅具备非接触、高精度和全场实时观测等特点,而且也实现了双材料界面粘接质量的定量无损检测。      

某大型厂房沉降观测实例浅谈

文章介绍了某厂房采用强夯地基处理后对该厂房的沉降观测、在实例中浅谈了沉降观测的基本要求，施测程序及步聚，对一些常见的问题给出了处理方法．实时观测及时反馈信息为勘察设计施工部门提供详尽的参考数据．预防在施工过程中出现不均匀沉降，避免因沉降原因造成厂房主体结构的破坏或产生影响结构使用功能的裂缝，造成安全隐患并带来巨大的经挤损失。     

X-ray fractography of a diesel engine crankshaft

X-ray (XR) diffraction is a well-known experimental technique used for measuring residual stresses in metallic materials. If we apply the XRD technique to the fracture surface of a broken part, it becomes a fractographical technique, that is to say that it is possible to relate the results of the measurement to the loading condition that lead a component to fail. However, in the past this technique was mainly used to analyse standard specimens and not mechanical components and there are few experimental investigations concerning the possibility of using this technique to investigate the cause of fatigue failures. In this paper, after a brief introduction to the technique, XRD fractography is applied to a diesel engine crankshaft that failed under known fatigue loading. It was possible to determine the load that lead the crankshaft to fail and to evidence some original aspects about the application of this technique to real machine parts. Comparison with finite element results served to confirm that XRD can be used as complementary tool to scanning electron microscope (SEM) observation or as a substitute to SEM observation, in the case of damaged fracture surface.     

Direct observation of powder agglomerated structure in ceramic slurries using optical microscopy

Direct observation of the powder structure in aqueous alumina slurry was investigated using optical microscopy in the transmission mode. In this technique, the slurry was sandwiched by two glass plates kept a 100 μm apart and the structure of powder agglomerates in the slurry was projected under optical transmission mode. It was revealed that the technique is powerful for examining large-scale heterogeneity in aqueous ceramic slurry of which the solid concentration is up to 10 vol.%.     

热镀锌合金化镀层相结构的定量化

金相法、扫描电镜、X射线衍射等技术不能定量地分析热镀锌层的相结构.为此,通过扫描电镜和电解剥离法分别对不同合金化时间的热镀锌层进行了相结构分析,将其与扫描电镜的观察结果进行对比.结果表明,电解剥离在足够低的电位扫描速度下可以使镀层中的各相逐相溶解,利用测得的极化曲线和各相的初始溶解电位对镀层中各合金相实现定量分析.     

用于高温光学实时观察的磁场装置

最近在我们实验室里建立了一套加磁场高温光学实时观察装置．作为磁场发生器的电磁铁,在发热体中心最高可产生0.14T的侧向磁场．运用这套加磁场实时观察装置,能有效地阻抑KNbO₃熔体内的重力对流,减少界面边界层厚度．     

Spectral Doppler estimation utilizing 2-D spatial information and adaptive signal processing

The trade-off between temporal and spectral resolution in conventional pulsed wave (PW) Doppler may limit duplex/triplex quality and the depiction of rapid flow events. It is therefore desirable to reduce the required observation window (OW) of the Doppler signal while preserving the frequency resolution. This work investigates how the required observation time can be reduced by adaptive spectral estimation utilizing 2-D spatial information obtained by parallel receive beamforming. Four adaptive estimation techniques were investigated, the power spectral Capon (PSC) method, the amplitude and phase estimation (APES) technique, multiple signal classification (MUSIC), and a projection-based version of the Capon technique. By averaging radially and laterally, the required covariance matrix could successfully be estimated without temporal averaging. Useful PW spectra of high resolution and contrast could be generated from ensembles corresponding to those used in color flow imaging (CFI; OW = 10). For a given OW, the frequency resolution could be increased compared with the Welch approach, in cases in which the transit time was higher or comparable to the observation time. In such cases, using short or long pulses with unfocused or focused transmit, an increase in temporal resolution of up to 4 to 6 times could be obtained in in vivo examples. It was further shown that by using adaptive signal processing, velocity spectra may be generated without high-pass filtering the Doppler signal. With the proposed approach, spectra retrospectively calculated from CFI may become useful for unfocused as well as focused imaging. This application may provide new clinical information by inspection of velocity spectra simultaneously from several spatial locations.     

Confocal light absorption and scattering spectroscopic microscopy

We have developed a novel optical method for observing submicrometer intracellular structures in living cells, which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light-scattering spectroscopy. CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales of the order of 100 nm.     

Shearography: A novel and practical approach for nondestructive inspection

This paper presents an optical technique referred to as shearography for nondestructive inspection. Shearography is an interferometric method which allows full-field observation of surface displacement derivatives. It reveals flaws in materials by looking for flaw-induced strain anomalies. Both surface and interior flaws can be detected. Because of its numerous advantages, shearography is more practical than holography. The simplicity and the alleviation of vibration isolation requirement make shearography a practical approach for nondestructive testing in field/plant environments.     

Fatigue limit evaluation of metals using an infrared thermographic technique

The paper aims to illustrate three advantages of infrared thermography as a non-destructive, real-time and non-contact technique. It permits first observation of the physical processes of damage and failure in metals, and in particular, automotive components subjected to fatigue loading, second detection of the occurrence of intrinsic dissipation, and third evaluation of the fatigue strength in a very short time, compared to traditional testing techniques. In addition, infrared thermography readily describes the damage location and the evolution of structural failure.     

海气界面观测浮标现场原位校准技术研究

海气界面观测浮标可长时间、连续不断地同步收集海面气象和水文数据,是全球海气相互作用研究的重要技术之一。分析了海气浮标校准工作存在问题,提出了一种海气界面观测浮标现场原位校准技术,依托国家浅海海洋综合试验场,进行海气界面观测浮标计量校准技术研究。海试数据显示现场原位校准技术可行、过程可控、结果可信,气象和水文参数均满足《气象观测规范》和《海滨观测规范》要求,可达到陆地校准技术精度要求,研究结果为海气浮标量值溯源提供了一种新的有效途径。     

In situ observation of filler displacement during tensile deformation of nanosilica-filled natural rubber using field-emission scanning electron microscope

An in situ observation technique of filler displacement during tensile deformation of a nanocomposite was developed by combining a field-emission scanning electron microscope (FE-SEM) with a tensile device. The direct observation was applied to a natural rubber (NR) vulcanizate filled with silica nanofillers. The displacement of the nanofillers was successfully observed while detecting the stress and strain of the vulcanizate simultaneously. The experimental results proved that this technique was suitable and useful for structural studies of nanoparticulate rubber.