射线透射图像中轻物质自动识别算法的研究

目的：针对射线透射图像中轻物质的自动识别存在的难点问题进行研究。方法：提出了基于轮廓特征和灰度特征的识别算法，结果：详细地阐述了利用识别算法进行识别的过程；结论：给出了识别算法的实验结果。     

高能双能X射线DR成像及物质识别技术综述

本文关注的是高能双能X射线透视成像以及成像中物体的识别和检测,按照从单能到低能双能再到高能双能的发展脉络介绍了双能X射线DR成像技术背景,详细阐述了高能双能X射线DR成像物质识别原理方法、技术特点和针对性改进,着重讨论了该方法能够用于物质识别的本质,并介绍了该领域面临的挑战和最新进展。     

射线透射成像中重物质遮挡下的轻物质检测技术研究

本文研究了不同厚度轻重物质在射线透射成像中的图像灰度关系，根据提取轻物质轮廓线的要求，找出了在不同厚度重物质遮挡下的可检测出轻物质的最小厚度曲线。     

基于双能量X射线透射技术的物质分类识别方法研究

X射线装置已被证实具有揭示物质的分子或原子特性的能力,这种特性对于探测违禁品是相当重要的.尽管X射线探测方法作为一种自动探测违禁品的有效手段已经开始商业化,然而大多数技术都还不是很成熟.研究了一种基于X射线透射技术的物质分类识别的更有效方法,物质按有效原子序数分成有机物、无机物和混合物,实验证明此方法是很有效的.     

2002年第11卷1～3期主要文章目次索引

[栏目]文章题目作者期-页码[CT理论]由相叠低分辨投影数据重建高分辨图像郭明焕张朋(2-12)PET图像基于形态学方法进行心脏的边缘提取骆国程赵永界(3-01)显微CT的锥束重建技术王革姜明等(3-07)[CT/MRI技术]CT图像存档与管理解决方案赵伟东阮昌京(1-13)CT机器、图像后处理技术的新进展何萍霞张玉花(1-44)9800MS胶片扫描管理系统简介姚健姜强(1-封3)[工业CT]数字化射线照相技术对轻物质的判断韩裕生罗娅丁厚本(1-10)射线透射成像中重物质遮挡下的轻物质检测技术研究邵立康韩裕生丁厚本(2-19)线阵探测器（LDA）的现状及发展趋势J.柯斯…     

氢氧稳定同位素在地下水异常核实中的应用

在地震地下流体研究中,区别地下水是受浅层物质补给还是受深部介质活动的影响,是异常核实的主要任务。氢氧稳定同位素技术能够有效地识别地下水的来源与补给过程。文中概述了氢氧稳定同位素方法在地下水异常核实应用中的基本原理、水样采集和测试技术,列举了应用氢氧稳定同位素技术研究井水位升高和水质浑浊异常现象的实例,就氢氧稳定同位素用于核实地下水水位、水温、化学组分和宏观异常进行了简要讨论。该方法的广泛使用,有助于识别地下水异常的构造与非构造影响因素。     

Hilbert-Huang变换在密频结构阻尼识别中的应用

Hilbert—Huang变换是一种新的数据处理方法，由经验模分解(Empirical Mode Decomposition)技术及Hilbert变换两部分组成。本文研究此方法对于密频结构阻尼识别的应用。首先对于两自由度系统模型，说明该方法用于阻尼识别的步骤。进而研究存在频率密集现象的高层建筑的阻尼识别问题。上述结果与理论值及由半功率带宽法的识别值进行了比较，对比显示Hilbert．Huang方法较传统方法具有良好的识别密频结构阻尼的性能，适用于大型结构的系统识别。     

应用人工神经网络技术的大型斜拉桥子结构损伤识别研究

本文应用人工神经网络技术对大型斜拉桥结构进行了子结构损伤识别研究。文中首先介绍了子结构损伤识别的基本方法，然后应用自组织竞争神经网络建立了对于大型桥梁结构识别子结构损伤情况的子结构损伤识别方法，并且应用BP网络进一步建立了大型桥梁结构各子结构内部的损伤位置和损伤程度的识别方法，数值模拟了一大跨度斜拉桥子结构损伤以及子结构内部损伤的识别过程，最后得出结论：(1)基于自组织竞争网络的子结构损伤识别方法能迅速准确地识别大型结构的损伤情况；(2)基于BP网络所建立的结构损伤识别方法，能对子结构中结构损伤的位置和程度进行进一步的识别；(3)基于人工神经网络技术的结构损伤识别方法是大型土木工程结构损伤识别的有效方法，可在工程结构损伤识别中广泛应用。     

浅谈多角度偏振遥感技术及其在探测月球资源中的应用

在反射、散射和透射电磁辐射的过程中，地表或大气中的目标地物将产生与它们自身性质相关的偏振特性.多角度偏振探测技术就是利用物质的这种偏振特性，对目标地物进行全方位、多角度的观测，是当前遥感识别目标地物的一种新手段，目前在我国还处于基础性试验研究阶段.本文从多角度偏振技术的物理机理出发，阐述了该种技术在当前“月球探测热”中的应用设想，表明在当前“重返月球”计划中多角度偏振探测技术应用的可行性.最后讨论了今后多角度偏振技术的应用与发展.     

基于Hilbert-Huang变换和随机子空间识别的模态参数识别

基于Hilbert-Huang变换和随机子空间识别技术提出了两种土木工程结构的模态参数识别方法。方法一是基于Hilbert-Huang变换和自然激励技术,通过经验模态分解和Hilbert变换提取信号的瞬时特性,进而利用自然激励技术和模态分析的基本理论识别结构的模态参数;方法二是基于经验模态分解和随机子空间识别技术,通过经验模态分解对信号进行预处理,进而运用随机子空间识别方法处理得到的结构单阶模态响应以识别结构的模态参数。利用这两种方法,通过对一12层钢筋混凝土框架模型振动台试验测点加速度记录的处理,识别了该模型结构的模态参数。识别结果与传统的基于傅里叶变换的识别结果及有限元分析结果的对比验证了这两种方法的可行性和实用性。     

Detecting the Zambezi River plume using observed optical properties.

In April 1998 a research cruise was carried out in the Mozambique Channel taking detailed optical, water quality and salinity measurements; the Zambezi plume waters were apparent through strong colour fronts with green waters in the plume and clear blue waters offshore. A good (r2 = 0.76) negative empirical relationship was found between the salinity (S) and yellow substance, represented by the absorption of filtered samples at 440 nm (g440). An empirical relationship was found between the salinity and a reflectance ratio: S(1/2 Zsd) = 37.45-7.07(R555/R490). An optical model in which light absorption is dominated by yellow substance and light scattering by inorganic particles confirms this empirical relationship. This has been applied to a SeaWIFS image to map salinity on the Sofala Bank, demonstrating the potential to remotely determine the distribution of the Zambezi River plume. It is thought that any significant level of chlorophyll would reduce the effectiveness of the above algorithm.     

Dependence of eelgrass (Zostera marina) light requirements on sediment organic matter in Massachusetts coastal bays: Implications for remediation and restoration

Using a calibrated bio-optical model we determined that the optical water quality conditions in several nitrogen-impaired embayments and in one unimpaired system were within the range of values known to support eelgrass growth. We also used the model to identify a range of light requirements for eelgrass (Zostera marina). Higher eelgrass light requirements, expressed as a percentage of surface-incident irradiance, corresponded with higher sediment organic matter content. These results corroborated findings by previous studies which indicate a generalized relationship: seagrasses growing in turbid conditions with poorer water and sediment quality have higher light requirements than those growing in less degraded conditions. The mechanistic reason for the variation in light requirements is still not completely explained and cannot be attributed to a single independent variable. Varying light requirement have important implications for eelgrass protection and should be considered when setting restoration targets for eelgrass in water quality and nitrogen remediation programs.     

基于主成分分析的多能谱CT图像分析方法研究

基于光子计数探测器的能谱CT,可以同时采集多个能谱通道的投影数据,并获得相应能量范围内物质的吸收特征,可以有效应用于物质识别与材料分解。主成分分析是一种很好的多元数据分析技术,可以用于处理多能谱CT数据。本文分别在投影域和图像域对能谱CT数据进行主成分分析,并对分析结果做出系统比较。为了减少噪声的影响,提高能谱CT图像的彩色表征性能,提出双域滤波与像素值平方相结合的方法,用于含噪声的主成分图像去噪,然后将所选取的主成分图像映射到RGB颜色通道。实验结果表明,无论是在投影域还是图像域进行主成分分析,都可以获取清晰的CT图像,识别出物质的不同成分。相较于在图像域的主成分分析方法,在投影域进行主成分分析能够保留物质的更多细节,获取更清晰的彩色CT图像。      

中华绒螯蟹鳃的组织及超微结构

中华绒螯蟹鳃详细的组织和超微结构研究结果显示,每条鳃由一扁平的鳃轴及其向两边发现片状鳃叶组成,鳃壁由角质层、上皮细胞和基膜构成。上皮细胞向角质层伸出指状突出以扩大表面积。上皮细胞向鳃腔突出延伸形成鳃腔隔。鳃腔内的膨大细胞实际上是上皮细胞向鳃腔内分裂形成突起,然后生长膨大而成,膨大细胞将鳃腔隔成迂回的通道,更有利于气候的交换和物质的吸收。     

Transformations of biogenic substances in Tatar Strait water (the Sea of Japan): Analysis of mathematical modeling results

The state of the marine environment (the temperature, light intensity, transparency, biogenic load) in Tatar Strait was assessed based on mean annual data from literary sources and with the use of GIS “Sakhalin Shelf.” The entire strait was divided into three regions (northern, southwestern, and southeastern), and water exchange between them for each month was estimated by using Bergen Oceanic Model. The information about the state of the marine environment and water exchange characteristics was used as input data for a hydroecological model, which enabled the assessment of annual variations of biogenic substance concentrations and biomasses of microorganisms (heterotrophic bacteria, three groups of phytoplankton, and two groups of zooplankton) in the strait regions chosen. The development conditions of microorganism biomasses within the year can be characterized by their activity indices (specific growth rates), the values of internal fluxes of biogenic substances, and calculated bioproductivity values. The calculated biogenic substance concentrations and phytoplankton bioproductivity values showed good agreement with the estimates for the Sea of Japan and Tatar Strait available from the literature.     

(光压)斥力相互作用在自然界客观存在的宏观证据

在宇宙中,众多恒星发出的光线充斥于万物之间.光压虽然早在1901年就被人们发现和试验证实,但一直未把它作为一种客观存在的自然力看待.其原因是(光压)斥力相互作用(自然力)主要表现在宇观物体(天体)上,在太阳系内的(太阳光压)斥力作用下,能否证明地球物质的宏观运动状态发生了变化及发生了什么样的变化,则是人们把(光压)斥力相互作用是否作为一种自然力看待的关键.宋贯一(1991)发现,太阳光压、地球的自转与公转组成了一套类似金属塑性压力加工中的一套天然"轧机",太阳的能量(动量)就是通过这种"轧制"式耦合物理机制传递给地球的,并依据这种耦合机制产生的地壳"轧展"效应特征,发现(1999)太阳光压斥力作用才是控制全球地壳运动和地震活动的唯一重要因素.宋贯一(1992)又发现,太阳光压、地球的自转与公转及赤黄交角的存在,组成了一套天然的日地间太阳能量(动量)相耦合的"摇摆"式物理机制,依据这种耦合机制特征,发现和证明(2006,2011)太阳光压斥力相互作用才是激发自转轴摆动并产生极移及地球自转速度季节性变化的主要力源.上述一系列发现,为(光压)斥力相互作用在自然界的客观存提供了具有说服力的证据.它与(万有)引力相相互作用一样,在宇宙的演化中起着同等重要的作用.     

Untersuchungen zur adsorptiven Abtrennung von leichtflüchtigen chlorierten Kohlenwasserstoffen (LCKW) aus huminstoffhaltigen Wässern mit neuartigen Adsorberpolymeren

Investigations of the Adsorptive Separation of Volatile Chlorinated Hydrocarbons (VCHC) from Water with Humic Substance by Novel Polymeric Adsorbents and Activated Carbons. Part I: Isotherms and Kinetics of Adsorption The isotherms and kinetics of adsorption of different volatile chlorinated hydrocarbons (VCHC) (1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene) and a humic substance from water as well as these VCHC from water with humic substance onto novel polymeric adsorbents (WOFATIT EP 63, DOWEX XUS 43493 and XUS 43546, MACRONET MN 100 and MN 200) were studied in comparison to activated carbons (NORIT ROW 0.8 SUPRA, PRECOLITH BKK 3, HYDRAFFIN CG). It was determined that the novel polymeric adsorbents remove the VCHC well and the humic substance in contrast to the activated carbons only a few. The decrease of the equilibrium loading for the VCHC due to the presence of humic substance is at the activated carbons approximately double as high as at the novel polymeric adsorbents, whereas in the kinetics of adsorption no substantial influences of the humic substance on the mass transfer were determined.     

Untersuchungen zur adsorptiven Abtrennung von leichtflüchtigen chlorierten Kohlenwasserstoffen (LCKW) aus huminstoffhaltigen Wässern mit neuartigen Adsorberpolymeren und Aktivkohlen. Teil II:: Dynamik der Adsorption

Investigations of the Adsorptive Separation of Volatile Chlorinated Hydrocarbons (VCHC) from Water with Humic Substance by Novel Polymeric Adsorbents and Activated Carbons. Part II: Dynamics of Adsorption In this publication, the dynamics of adsorption of different volatile chlorinated hydrocarbons (VCHC) (1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene) and a humic substance from water as well as of these VCHC from water with humic substance onto novel polymeric ad-[QJ][HR] sorbents (WOFATIT EP 63, DOWEX XUS 43493, MACRONET MN 100 and MN 200) was studied in comparison to activated carbons (NORIT ROW 0.8 SUPRA, PRECOLITH BKK 3, HYDRAFFIN CG). The obtained breakthrough curves and the following predicted characteristic values reveal that the polymeric adsorbents do not remove or remove the humic substance only with low adsorption capacity in contrast to the activated carbons. At the adsorption of the VCHC from water with humic substance it was determined that the influence of the humic substance on the adsorption capacity is substantially less on polymeric adsorbents than on activated carbons.