Application of ENVISAT ASAR Data in Mapping Rice Crop Growth in Southern China

This research letter presents preliminary results of mapping rice crop growth using ENVISAT advanced synthetic aperture radar (ASAR) alternating polarization HH/HV data. Four ASAR HH/HV images were collected in the early rice-growth cycle in the test site in 2006, and the temporal response of ASAR data to the rice field was analyzed. The height and biomass of rice were measured during acquisition of ASAR data, and empirical relationships were established between the backscattering coefficient and these two parameters. Based on the temporal variation of the radar response, a method for mapping a rice growth area was developed using the combination of ASAR HH and HV polarization data between two acquisition dates. The results confirm that C-band SAR data have great potential in the development of an operational system for monitoring rice crop growth in Southern China.     

Experimental verification of a wireless sensing and control system for structural control using MR dampers

The performance aspects of a wireless ‘active’ sensor, including the reliability of the wireless communication channel for real‐time data delivery and its application to feedback structural control, are explored in this study. First, the control of magnetorheological (MR) dampers using wireless sensors is examined. Second, the application of the MR‐damper to actively control a half‐scale three‐storey steel building excited at its base by shaking table is studied using a wireless control system assembled from wireless active sensors. With an MR damper installed on each floor (three dampers total), structural responses during seismic excitation are measured by the system's wireless active sensors and wirelessly communicated to each other; upon receipt of response data, the wireless sensor interfaced to each MR damper calculates a desired control action using an LQG controller implemented in the wireless sensor's computational core. In this system, the wireless active sensor is responsible for the reception of response data, determination of optimal control forces, and the issuing of command signals to the MR damper. Various control solutions are formulated in this study and embedded in the wireless control system including centralized and decentralized control algorithms. Copyright © 2007 John Wiley & Sons, Ltd.     

浅谈电视天气预报节目解说词的编写

目前,山西省的电视天气预报节目主持人大都不是气象专业人员,因此,解说词的编写质量高低就成了整个天气预报节目能否取得观众认可的一个重要因素。要编一份成功的解说词,不仅要及时掌握大量的实时气象信息,也要充分了解本地天气气候背景,还要学习积累气象科普、专业服务等多方面的知识,并运用娴熟的文学技巧,从通俗易懂的角度向观众朋友们传递方便实用的气象信息。     

三门峡地区黄土L9的重磁化现象及原因探析

对黄河三门峡地区曹村黄土剖面L₁至L₁₃(年代持续约1.1Ma)的高分辨率古地磁研究发现:布容/松山界线位于第8层古土壤(S₈)的顶部,贾拉米洛正极性亚时的顶、底界分别位于S₁₀和L₁₃的顶部,上述古地磁极性转换界线与洛川标准剖面一致。“上粉砂层”(L₉)的绝大多数样品特征剩磁方向与现代地磁场方向一致,而其中的弱发育古土壤层(L₉SS₁)则呈预期的反极性特征。综合L₉的厚度、岩性和岩石磁学特征,认为这一巨厚的正极性带可能反映了完全由岩性所控制的重磁化特征。对于L₉重磁化的原因,似乎很难用后生的化学剩磁和粘滞剩磁来解释。文章尝试性地提出,可能在L₉沉积后的间冰期(对应S₈)和布容正极性时内气候较湿润的时期,由于雨水的向下渗透而诱导了其中强磁性矿物(磁铁矿)在沉积后随地磁场方向的变化而进行了重新排列。     

自适应模糊规则分类方法及在TM土地覆盖分类中的应用研究

根据自组织网络和模糊逻辑推理,实现土地覆盖自适应模糊规则分类方法。该方法通过网络的节点和权值提取出模糊规则,调整网络中节点个数(即相应增加规则节点数)和权值向量,使模糊规则自动生成,并利用模糊逻辑推理,完成TM土地覆盖分类。对拒分类的像元,自适应增加K值使其可分。该方法所得分类精度及Kapp系数与最大似然分类方法结果相比分别提高了2.7%和2.9%;与自组织网络相比,总精度相差不大,而Kapp系数低1%。实验证明,如何提取和表示非光谱知识,从而解决类别混淆等问题,是提高自适应模糊规则分类性能的关键     

安达曼弧段强震与中国大陆西部强震相关性的讨论

分析了安达曼弧段强震与中国大陆西部强震的活动特征,从强震的空间分布格局、板块边界动力学数值模拟、数理统计等方面讨论了两区强震活动的相关性。结果表明两区强震活动存在较强的相关性,近期安达曼弧段强震活跃态势将会对大陆西部未来1年及稍长时段的强震活动产生深远的影响。     

贵州旅游地学资源初探

根据贵州特点,将贵州旅游源分为９大类：地学景观类,地学遗迹类,水文景观类,运动、疗养、休闲、度假类,天象景观类,生物景观类,人文景观类,民族风性类和土特产品类。为合理开发和保护贵州旅游资源,作者提出了一些建议。     

浓集值在矿床预测中的应用

有用物质可否成为矿床,取决于某元素含量与最低工业品位的比值。使用浓集值可以预测和判定找矿矿种一成矿元素,发现新的矿产地。     

“3S”技术在煤田勘查中的应用

讨论了“３Ｓ”技术用于煤田地质勘探的优越性,分析了“３Ｓ”技术在烟田地质勘查领域的应用现状及存在的问题,并展望了应用前景。     

低水合氯化镁吸水过程的气相色谱热力学研究

利用迎头气相色谱分析、量热法、热重法、X -衍射法和化学分析相结合 ,对氯化镁水合物吸水和脱水过程进行了热力学研究。在不同温度下对MgCl2 ·4H2 O和MgCl2 ·2H2 O对水的吸附等温线所进行的数学模拟结果表明 ,Bolzmann函数是描述该等温线较为理想的方程。两种氯化镁水合物对水的吸附热分别为 -1 3 0 6kJ/mol和 -1 6 1 1kJ/mol。也给出了该吸附过程的吸附平衡常数。从所获得的数据来看 ,以部分脱水的氯化镁水合物为吸附剂来吸附水氯镁石脱水设备尾气中的水蒸气 ,从而使保护性气体HCl得以循环使用 ,从热力学角度而言存在这种可能性。