9711号北上台风演变及暴雨过程的位涡诊断分析

通过对 971 1号台风登陆北上穿过山东造成山东特大暴雨过程的湿位涡的分析 ,并从湿位涡的角度研究了台风演变及山东特大暴雨的形成机制 ,揭示了冷空气在台风演变及暴雨过程中的重要作用。结果表明 :倾斜涡度发展是暴雨产生和台风加强的重要机制之一 ,暴雨产生在 θe线陡立密集区内 ;湿位涡在这次暴雨过程中对流层低层具有 MPV1 <0 ,MPV2 >0的特征 ,此次暴雨产生在负的MPV1等值线密集区中 ;对流层上部及平流层下部高位涡的下传使得低层斜压性增大 ,引起低层的对流稳定度减小 ,促使气旋性涡度发展 ,有利于位势不稳定能量的释放 ,使得暴雨增幅 ,导致台风的加强并演变为温带气旋。     

A STUDY OF THE DISTRIBUTION OF RECENT OSTRACOD FAUNAS FROM COASTAL AREAS OF THE EAST CHINA AND YELLOW SEAS

A total of 91 species belonging to 57 genera were recovered from the coastal areas of the north East China Sea ana the south Yellow Sea, of which, 42 species of 30 genera were collected alive. The biocoenoses of estuaries, supralittoral and eulittoral zones are dominated by orackish and euryhaline species, of which Albileberis sheyangensis, A. sinensis, Leptocythere ventriclivosa, Loxoconcha ocellata, Sinocytheridea latiotata and S. longa are ubiquitous; Propontocypris euryhalina, Spinileberis furuyaensis and S. pulchra are restricted to the supralittoral zone; Neomonoceratina crispata and Pontocythere lit-toralis are only present in the eulittoral zone. The community structure of these biocoenoses is generally marked by low snecies diversity (H(S) and 5) and high incidence and dominance. Among the environmental factors investigated, it was found that salinity was the most important in controlling the distribution of living ostracods, and high-energy hydrodynamic condition was the main cause of the grea     

基于分块分形编码的多姿态、表情人脸图像检索

利用图像分形编码中定义域块和最小均方误差一一对应的特点，提出了1种基于分形编码的多姿态、表情的人脸图像检索方法。该方法将待检索图像分割为相同大小的值域块，然后将每一值域块按给定的定义域块进行分形编码，得到最小均方误差，计算该最小均方误差与图像库中最小均方误差的欧氏距离。将待检索图像所有值域块的欧氏距离求平均，此平均欧氏距离较小的几幅图像即为检索出的图像。实验证明该方法能够准确地检索出图像库中存储的同一人的不同姿态、表情的图像。     

海洋走航式单边连续观测地震折射波Δt解释方法--1种新的浅层折射单支时距曲线解释方法

在浅层工程折射地震测量中 ,通常采用相遇观测系统采集数据和相应的解释方法进行解释 ;对于单边观测采集方法由于与其相应的解释方法较少而少被采用。本文提出 1种方法简单、精度可靠、可直接利用同一点相邻 2排列 2次观测的初至折射时间并适合于海洋走航式单边连续观测系统的折射初至资料解释方法。其精度基本与同观测段的采用相遇观测的差异时距方法解释的精度十分接近。该方法即适合于人工解释又适合于计算机自动解释。     

基于顶点度的多分辨率表示

针对边收缩算法在计算大曲率面距离公差时计算量大 ,且收缩大曲率面所含的线段时易使关键点发生偏移而引起模型变动过大、简化不够准确的问题 ,本文在边收缩算法基础上提出了加入顶点度控制的算法 ,以减少大曲率面距离公差的冗余计算 ,并提高模型简化质量。实验表明该算法能提高模型简化质量 ,并加快图形收缩的生成速度。     

A Preliminary Study of Shear Wave in Seafloor Surface Sediments

This article preliminarily reports and analyses the transmission characteristics and behaviors of shear wave in the offshore seafloor surface sediments in China, discusses the relationships between the physical and mechanical features of the shear wave and the compression wave, and compares the testing results with that of Hamilton and Chen et al. The result shows that the shear wave can be tested if the seafloor surface sediment has tangent modulus. The shear wave velocity ranges from 50-600 m/s and the measuring frequency from 50-200 kHz. The sound velocity rate of shear wave and compression wave can be used to appraise the stress-strain feature of seafloor surface sediments. This study provides a basis for further describing and appraising the seafloor sedimentary acoustic-mechanical feature and building a geological-acoustic model on China's offshore sea area.     

基于EMD与神经网络的机械故障诊断技术

经验模式分解 (EMD)是分析非线性、非平稳信号的有力工具 ,它将信号分解为突出了原信号的不同时间尺度的局部特征信息的内在模函数 (IMF)分量。本文通过将各 IMF分量输入到 BP网络中进行训练学习和故障诊断 ,比直接输入原信号可以提高 BP网络对故障诊断的准确率 ,而且减少了训练时间。     

Vertical Sound Velocity Transition in the Coral Reef Core and Its Significance of Indicating Facies

On the basis of the sound velocity measurements of the coral reef core from Nanyong No.1 well of Yongshu Reef in the Nansha Islands,the paper studies the relations between the vertical sound velocity transition features in the coral reef core and the corresponding stratigraphic depositional facies change as well as stratigraphic gap of erosion,analyses the cause of the sound velocity transition,expounds the concrete process of the sea level change resulting in the stratigraphic gap of erosion and facies change in the coral reef and explains the relations between the vertical sound velocity transition in the coral reef core and the corresponding stratigraphic paleoclimate and the sea level change.This study is of important practical value and theoretical significance to the island and reef engineering construction and the acoustic logging for oil exploration in the reef limestone area as well as the paleoceanographic study of the marginal sea in the westerm Pacific Ocean.     

地理信息系统技术在地名数据库更新维护中的应用

利用MapObjects进行地理信息系统二次开发建立的地名更新维护应用系统,哥以实现地理空间数据库(Geodatabase)要素类的访问和操作,在实现复杂要素通用GIS编辑功能的同时,利用ArcSDE还可以实现多用户网络化操作和管理,降低了开发成本.     

基于GIS的建筑用地钉桩数据录入系统开发

利用GIS技术开发完成了建筑用地钉桩录入系统,利用数据下载机制和时间戳,实现了数据库的离线编辑,解决了网络用户同时编辑时数据库冲突问题。通过专门的录入界面,使存储在ArcSDE空间数据库和ORACLE上的其它描述信息同时更新,保持数据一致行和实效性。