船-桥避碰监测预警系统研究

为提高桥区船舶航行安全,提出一种基于智能视频处理技术的船-桥避碰监测预警系统。该系统实时采集桥区场景视频,利用视频处理技术自动检测运动船舶目标,基于视觉几何模型进行船舶空间定位,提取船舶运动态势参数,并结合船舶航行操纵知识和相关模型,进行船-桥碰撞风险预测,输出避碰操纵命令。大量仿真及现场试验结果表明,该系统能检测出航行异常船舶并输出避碰操纵命令,达到主动避碰的目的。     

基于表面增强拉曼光谱的水中芳香胺类污染物现场快速检测技术

利用表面增强拉曼光谱（SERS）对水中芳香胺类污染物进行检测分析.通过化学法合成具有SERS活性的银胶,紫外可见光谱、动态光散射及扫描电子显微镜表征显示制备的银胶分散性良好、粒径均匀;选用背景散射弱、价格便宜的薄层色谱板为承载基底,利用所制备的银胶并结合便携式拉曼光谱仪对芳香胺类污染水样进行现场快速检测,结果显示,适当...     

Two leaks detection in viscoelastic pipeline systems by means of transient

This paper presents a technique for detecting and locating leaks in a single viscoelastic pipe, by means of transient analysis. The system studied is a reservoir-pipe-valve structure. The viscoelastic behavior of the pipe wall material is modeled by a generalized KelvinVoigt model. To determine the leak location, the mathematical formulation has been solved by the method of characteristics. The approach by the method of characteristics is often chosen because it is based on the concept of acoustic wave propagation which is the main mechanism of all transient events considered. The presence of the two leaks in a pipe partially reflects pressure waves initiated by the sudden closure of a downstream shut-off valve. These waves affect the shape and the amplitude of the time-history-pressure. The computed results describe the influence of the presence of two leaks on pressure time-history and the effect of leaks locations and sizes on the pressure signal behavior. The effect of the pipe wall viscoelasticity on the two leaks detection and sizing is also discussed. The leaks discharges are determined by resolving two independent equations derived from literatures and based on transient analysis. The friction and leaks depths effects on two leaks locations and sizing are involved.     

气体质量流量控制器在汽车VOC检测领域的应用

汽车挥发性有机物组分(VOC)检测过程中,充气和采气体积的计量对检测结果的影响尤为突出.通过气体质量流量控制器与目前VOC检测中常用的恒流气体采样装置的比较,表明在同样满足VOC检测标准要求的情况下,气体质量流量控制器在排除环境干扰等方面体现出更好的稳定性,更有利于汽车VOC检测准确度的提高.     

Hydrography Change Detection: The Usefulness of Surface Channels Derived From LiDAR DEMs for Updating Mapped Hydrography1

Abstract: The 1:24,000‐scale high‐resolution National Hydrography Dataset (NHD) mapped hydrography flow lines require regular updating because land surface conditions that affect surface channel drainage change over time. Historically, NHD flow lines were created by digitizing surface water information from aerial photography and paper maps. Using these same methods to update nationwide NHD flow lines is costly and inefficient; furthermore, these methods result in hydrography that lacks the horizontal and vertical accuracy needed for fully integrated datasets useful for mapping and scientific investigations. Effective methods for improving mapped hydrography employ change detection analysis of surface channels derived from light detection and ranging (LiDAR) digital elevation models (DEMs) and NHD flow lines. In this article, we describe the usefulness of surface channels derived from LiDAR DEMs for hydrography change detection to derive spatially accurate and time‐relevant mapped hydrography. The methods employ analyses of horizontal and vertical differences between LiDAR‐derived surface channels and NHD flow lines to define candidate locations of hydrography change. These methods alleviate the need to analyze and update the nationwide NHD for time relevant hydrography, and provide an avenue for updating the dataset where change has occurred.     

我国地质矿产部门工业卫生现状

对地质矿产部门１９９１年初至１９９２年底开展的工业卫生普查工作资料进行分析，简述了职业危害人群分布、现场监测、职业病的现状及危害原因，提出了防护措施和改进意见。     

Monitoring a Recent Delta Formation in a Tropical Coastal Wetland Using Remote Sensing and GIS. Case Study: Guapo River Delta, Laguna de Tacarigua, Venezuela

The integrated use of remotely sensed data and GIS to monitor a rapid recent delta formation was undertaken in the Tacarigua Lagoon, a mangrove coastal protected wetland in the north-central coast of Venezuela. Recently, the resource value of coastal wetlands such as coastal lagoons and deltas, has brought about a need to protect and conserve these ecosystems. To that end, valuable resources such as these should be continuously monitored so that temporal changes in their environment can be analysed. The importance of determining the cause, extent, and spatial distribution of these changes can then be used in different aspects of environmental studies, land suitability analyses and for wise resource management. Aerospace data interpretation and a field survey were utilised to study the formation of the Guapo River delta within the Tacarigua Lagoon and to map the expansion that this depositional environment has undergone. A historical set of aerial photographs and a radar image, together with a GIS, were used to assess the growth of the delta from the beginning of its formation up to the present time.     

Prenatal detection of free sialic acid storage disease: genetic and biochemical studies in nine families

Sialic acid storage disorders, Salla disease (SD) and a severe infantile form of disease (ISSD), are recessively inherited allelic lysosomal storage disorders due to impaired egress of free sialic acid from lysosomes. Fourteen pregnancies at risk of adult-type free sialic acid storage disease, SD, were monitored by sialic acid assays, genetic linkage or mutation detection analyses using chorionic villus samples. Three affected and 12 unaffected fetuses were identified. The first studies were based on the sialic acid assays alone, but the location of the gene enabled the use of genetic linkage analysis and, more recently, the identification of the SLC17A5 gene and disease-causing mutations added yet another possibility for prenatal studies. A missense mutation 115C→T (R39C) is present in 95% of all Finnish SD alleles, providing an easy and reliable means of diagnostic studies. Both molecular and biochemical (sialic acid assay) studies can be used for prenatal diagnosis of free sialic acid storage diseases. Copyright © 2001 John Wiley & Sons, Ltd.     

Detection of hydroxyl radical in plasma reaction on toluene removal

A new method was introduced to detect the concentration of OH radical in dielectric barrier discharge(DBD)reaction.A film, which was impregnated with salicylic acid,was used to detect OH radical in plasma reaction at room temperature and atmospheric pressure.Salicylic acid reacts with OH radical and produces 2,5-dihydroxybenzoic acid(2,5-DHBA).Then,a high performance liquid chromatography(HPLC)was carried out to detect the concentration of 2,5-DHBA.Therefore,OH radical in nonthermal plasma reaction could be...     

废钯炭催化剂分析方法的研究

对废钯炭催化剂分析方法进行了研究,将废钯炭催化剂用高温煅烧的方法除去其中的活性炭并收集燃烧气体中的含钯微粒,采用甲酸代替碱性甲醛溶液或氨性水合肼作还原剂,过氧化氢-盐酸混合溶液代替王水作溶剂,提出了一种方法简单、浸出效果好、易操作的废钯炭催化剂分析钯的方法。试验表明,本方法适用于实际分析检测应用。