L波段雷达探测系统几种特殊故障的处理

为确保L波段雷达能准确、可靠、安全连续的正常运行,并在大气监测现代化建设中发挥应有的作用,雷达探测系统的保障将起到关键作用。文章针对东胜L波段雷达探测系统运行中出现的个例故障进行原因分析,并找出相应的解决办法,保证系统的正常运行。     

基于建筑性能的非结构构件抗震设计研究

针对非结构构件在地震中破坏的现象、震害情况,分析破坏原因,给出了非结构构件的抗震设防目标。基于建筑物性能的基本思想,给出了非结构构件的性能设计要求;讨论了非结构构件和附属设备的抗震设计计算原则。对建筑的非结构构件提出了相应的抗震设防技术措施,以提高其抗震能力。     

辽西中生代沉积岩稀土、微量元素地球化学特征及其构造背景

辽西地区在中生代时期经历了三次火山-沉积旋回,形成的沉积岩中蕴含大量的地壳演化信息。采用电感耦合等离子体质谱（ICP—MS）测定了该区中生代沉积岩的稀土、微量元素含量,应用微量元素La—Sc—Th,Th—Co—Zr／10沉积构造背景判别图解对区域构造背景进行了探讨。结果表明：①中生代沉积岩稀土元素含量较高,具有后太古宙沉积岩特征;②三叠纪不同时期沉积岩具有相同的微量元素曲线分布型式,侏罗纪、早白垩世期间沉积岩的稀土元素曲线相对分散,分别具有两种、三种微量元素分布曲线型式,反映沉积物源的变化和活化的沉积构造背景;③中生代时期,构造环境复杂,大陆岛弧型为主,三叠纪-侏罗纪期间处于转型期,兼有稳定的被动大陆边缘型特征,早白垩世兼有活动大陆边缘型特征,构造环境更为活化。     

基于粮食安全策略的耕地需求量预测研究--以湖北省为例

常见的耕地需求量预测方法主要是采用回归分析法、灰色预测法,缺乏对自然和社会因素的内在分析,忽略了国家粮食安全策略的影响。但是耕地保护与粮食安全之间存在着相当密切的联系,因此,本文基于国家粮食安全策略考虑进行耕地需求量的预测。结合国民经济发展及各用地部门需求,考虑规划期间耕地减少和增加的各种可能性,最终确定耕地需求的合理规模。     

石羊河流域生态危机的综合治理探讨

综合治理石羊河流域生态危机的思路是:①用一定生活水平下的人均耕地面积阈值和最佳防护效益森林覆盖率理论,确定的耕地面积和配套的防护林体系。②用生物群落类、湿地类及流域经济社会类3大用水阈值组成的生态用水阈值进行水资源配置或调控。调控过程中紧紧抓住人口的环境容量这个关键,用人口环境容量调控和耦合生产及经济规模基础上,通过调控流域内可利用水资源承载力各分量的方式,对水资源配置进行优化,达到遏制生态危机,促进生态和经济可持续发展的目的。     

黄河清8出汊河口泥沙异重流特征及其时空分布

选用1996年9月5—6日黄河口新口门水文泥沙同步观测资料,采用距离倒数加权插值法(IDW)生成河口泥沙异重流的含沙海水密度、流速和含沙量随时间变化的等值线图。基于此,分析了黄河口泥沙异重流发育形成的时空变化特征,并结合遥感影像和水下地形图进一步探讨了泥沙异重流对河口沉积的影响。研究结果表明,黄河口(新口门)泥沙异重流发育频繁,且其形成时的含沙海水密度与老河口相似;泥沙异重流的空间分布与水下三角洲泥沙堆积体及河口沙嘴的形态存在明显相关,泥沙异重流的存在直接影响河口前缘泥沙的沉积,但对侧缘的影响不大;泥沙异重流形成初期,在低高潮涨潮阶段中的一次较小的涨落潮周期内其形成和消亡过程与潮流的涨落潮周期呈正向对应关系,且在这一时段的涨憩时泥沙异重流的泥沙含量达到最大;流速垂向分布为泥沙异重流形成初期流速小于上层海水流速,且层次分明,随其进一步向深海运动流速呈增大再减小的趋势,至三角洲前缘陡坡段其底层流速大干中上层海水流速。     

风暴潮前后莱州湾西岸滩演化特征研究

Multiple surveys were conducted before and after storm surge at four beach sections,Sediment samples were analyzed and numerically simulated for understanding the characteristicsof becach reaction to storm surge and morphological evolution ,The results show that the sediment sources in this area do not increase in amount;the beach is basically stable in normal weather.While in gale weather,sediment from Yellow River and the eroded matters from the bank becomes a part of the sediment sources.The northem beach of Xiaoqing estuary is eroded seriously, while the southern beach is overall stable,Thw tidal creeks changed from the northern beach are transported greatly sea-ward and the inshore sediment becomes sandy,while that of the southem beach becomes silty,The sand transporting capability is almost 100 times of that in nomal weather. Human activities and big storm surges are the main reasons for the beach evolution.     

基于FT-IR、GC及核磁共振的仿刺参(Apostichopus japonicus)消化道多糖结构解析研究

仿刺参(Apostichopusjaponicus)因其高营养价值并富含多种生物活性成分,具有重要的经济价值。为了充分利用仿刺参加工下脚料,提高养殖经济效益,本文采用复合蛋白酶解法提取仿刺参消化道多糖,研究了酶解温度、时间、pH及加酶量对仿刺参消化道多糖得率的影响,并通过正交实验对仿刺参消化道多糖提取工艺进行优化,利用DEAE-sepharoseFastFlow层析柱对多糖进行纯化,通过傅里叶红外光谱(FT-IR)、气相色谱(GC)及核磁共振(13C, 1H谱)对多糖的结构及组成进行分析。结果表明,复合蛋白酶在pH 7,加酶量1.2?104 U/g,温度60℃酶解6h;利用Sevage法脱蛋白提取得到的仿刺参消化道多糖纯度均一,效果最佳。通过FT-IR结果判断其为糖类化合物,含有β型葡萄毗喃糖苷键;利用气相色谱确定该多糖主要由鼠李糖、岩藻糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖六种单糖组成,其摩尔比为1︰32.86︰14.56︰1.66︰0.78︰10.43,其中岩藻糖的含量最高;核磁共振综合分析结果进一步证实仿刺参消化道多糖含有β型毗喃已糖,且主要是以l, 4-糖苷键相连接。     

基于重心-GTWR模型的京津冀城市群研究

Research into urban expansion patterns and their driving forces is of great significance for urban agglomeration development planning and decision-making.In this paper,we reveal the multi-dimensional characteristics of urban expansion patterns,based on the intensity index of the urban expansion,the differentiation index of the urban expansion,the fractal dimension index,the land urbanization rate,and the center of gravity model,by taking the Beijing-Tianjin-Hebei(Jing-Jin-Ji)urban agglomeration as an example.We then build the center of gravity-geographically and temporally weighted regression(GTWR)model by coupling the center of gravity model with the GTWR model.Through the analysis of the temporal and spatial patterns and by using the center of gravity-GTWR model,we analyze the driving forces of the urban land expansion and summarize the dominant development modes and core driving forces of the Jing-Jin-Ji urban agglomeration.The results show that:1)Between 1990 and 2015,the expansion intensity of the Jing-Jin-Ji urban agglomeration showed a down-up-down trend,and the peak period was in 2005-2010.Before 2005,high-speed development took place in Beijing,Tianjin,Baoding,and Langfang;after 2005,rapid development was seen in Xingtai and Handan.2)Although the barycenter of cities in the Jing-Jin-Ji urban agglomeration has shown a divergent trend,the local interaction between cities has been enhanced,and the driving forces of urban land expansion have shown a characteristic of spatial spillover.3)The spatial development mode of the Jing-Jin-Ji urban agglomeration has changed from a dual-core development mode to a multi-core development mode,which is made up of three functional cores:the transportation core in the northern part,the economic development core in the central part,and the investment core in the southern part.The synergistic development between each functional core has led to the multi-core development mode.4)The center of gravity-GTWR model combines the analysis of spatial and temporal nonstationarity with urban spatial interaction,and analyzes the urban land expansion as a space-time dynamic system.The results of this study show that the model is a feasible approach in the analysis of the driving forces of urban land expansion.     

特高压输电铁塔聚束模式SAR干涉特性研究与覆冰试验

本文基于多幅TerraSAR卫星聚束模式SAR影像,研究了武汉特高压试验基地内特高压输电铁塔的雷达散射机制和干涉特性。利用高精度LiDAR扫描铁塔并进行三维建模,基于SAR几何成像关系分析了铁塔不同部位的散射几何关系。对比分析了基于散射强度和投影几何关系量测的铁塔横担间的高差,以及干涉图中相位变化反演的高差。结果表明相位推算的高差受噪声的干扰较大。本文对覆冰铁塔构件的雷达影像进行了理论分析和数据统计。结果表明,10 cm覆冰厚度破坏了铁塔构件二面角散射条件,造成雷达散射信号强度衰减了约8 dB,这表明输电铁塔雷达散射强度的变化可用于量化评估铁塔的覆冰状态。