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61.
In mountainous areas, it is the undulant terrain, various types of geomorphic and land use that make the remote sensing images great metamorphism. Moreover, due to the elevation, there are many areas covered with shadow, clouds and snow that make the images more inaccurate. As a result, it would be very difficult to carry out auto-classification of RS images in these areas. The study took Southwest China as the case study area and the TM images, SPOT images as the basic information sources assisted by the a... 相似文献
62.
The Yangtze Estuary, the largest estuary in China, is under an obvious interaction between runoff and astronomical tide. The research on the interaction is very important for the exploitation and utilization of water resources in this area. A horizontal 2D hydrodynamic numerical model is established and verified in the present study with the modeling range from Datong to the Yangtze Estuary. Based on the comparison of high water levels under the interaction between different runoff and estuarine dynamics, s... 相似文献
63.
PANG Jungang LI Wenhou XIAO Li. School of Petroleum Resources Xi'an Shiyou University Xi'an China. Geological Department Northwest University Xi'an China. State Key Laboratory of Continental Dynamics China. Geological Research Institute of Shengli Oilfield Co. Ltd. SINOPEC Dongying Sh ong China 《东北亚地学研究》2009,(4):183-188
Lacustrine turbidite of Chang-7 Member in the studied area consists of sihstone and fine sandstone with respect to grain size, which is feldspathic lithie sandstone, syrosem arkose and arkose with respect to mineral constitution affected by provenance. There are such apparent signatures as lithology, sedimentary structure, sedimentary sequence and well logs, to recognize turbidite. During the paleogeographic evolution of Chang-7 Member, lake basin and deep lake are both at their maximum extent during Chang-73 stage, resulting in the deposition of Zhangjiatan shale with widespread extent and of turbidite with fragmental-like. Deep lake line is gradually moving toward lake center and turbidite sand bodies are gradually turning better with better lateral continuity, connectivity and more thickness, from stages of Chang-73, Chang-72 and Chang-7t, which can be favorable reservoir in deep-water. 相似文献
64.
异常流量在目的地址与出现时间上的分布均与正常流量有很大区别。文中对校园网的出口流量进行分析实验,将其NetFlow记录按校外IP地址的前16位聚类,得到的部分网段在出入流量中的出现频度有明显特点。分析2种典型网段,研究由此发现校园网内的异常流量源的方法,并对2种异常流量源的区别进行了分析。此方法与常用的异常检测方法相比,所需处理的数据量大为减少,大大提高了检测效率。 相似文献
65.
Mathematical Models for Combined Refraction-Diffraction of Waves on Non-Uniform Current and Depth 总被引:12,自引:2,他引:12
Hong Guangwen
Professor Research Institute of Coastal Ocean Engineering Hohai University Xikang Road Nanjing 《中国海洋工程》1996,(4)
Two mathematical models for combined refraction-diffraction of regular and irregular waves on non-uniform current in water of slowly varying topography are presented in this paper. Model I is derived by wave theory and variational principle separately. It has two kinds of expressions including the dissipation term. Model n is based on the energy conservation equation with energy flux through the wave crest lines in orthogonal curvilinear coordinates and the wave kinematic conservation equation. The analysis and comparison and special cases of these two models are also given. 相似文献
66.
Single Zircon LA-ICP-MS U-Pb Dating of the Guandimiao and Wawutang Granitic Plutons in Hunan, South China and Its Petrogenetic Significance 总被引:1,自引:0,他引:1
CHEN Weifeng CHEN Peirong ZHOU Xinmin HUANG Hongye DING Xing SUN Tao The Key Laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing Jiangsu No. Research Institute CNNC Changsh Hunan 《《地质学报》英文版》2007,81(1):81-89
1 Introduction The South China Block (SCB), located between the Qinling-Dabie and Songma Indosinian sutures, experienced successively two important tectonic movements during the Mesozoic, i.e. the Indosinian movement (early Mesozoic) and the Yanshanian movement (late Mesozoic). Therefore, the generally accepted viewpoint is that the key geological problems during the Mesozoic are essentially the dynamics and material expression of these two tectonic movements in South China (Chen et al.… 相似文献
67.
A numerical wave flume is constructed based on the Reynolds Averaged Navier-Stokes (RANS) equations with turbulence closure by a modified k-ε model to study the viscous interactions of waves with vertical breakwaters for different overtopping cases. The governing equations,the turbulence model,boundary conditions,and solution method for the numerical wave flume are introduced briefly. The reliability of the numerical wave flume is examined by comparing the numerical results with the experimental measurement... 相似文献
68.
简述了原国家重力基本网(57网)的历史和技术要点,详细地分析了57网的各类误差和产生原因,提出了新、旧系统转换的方法。本文研究表明,57网基本点相对观测的实际精度约为±0.06mgal,仪器平均值误差为1.6×10~(-4)。基本点重力值含-13.56mgal的基准误差和1.9×10~(-4)的尺度差,并含有±0.1~0.2mgal的非线性系统误差。对基本点实行新、旧系统转换误差为±0.05mgal,基本不损失其观测精度。 相似文献
69.
通过横流太平洋往返两个航次随船调查,研究了采用气象导航对减少燃油消耗和保证船舶安全、班期等,不但有定的经济效益,而且是一种非常有效的航运管理方法。 相似文献
70.
Xia Zhenhuan. Professor Dept. Hydraulic Engineering. Tsinshua University. Song Genpei. Lecturer. kept. Hydraulic Engineering. Tsinghua University. Chen Yiping. Assistant. Dept. Hydraulic Engineerins Tsomghua University Wang Gang. Engineer. Research institute of Naval Engineering. PLA 《国际泥沙研究》1990,(1)
1. INTRODUCTIONAs a wide range of size distirbution including usually a certain POrtion of cohesive material is thecommon feature of the sediment constituting hyperconcentrated flows. it is desirable to study the settling properties of mixtures of cohesive and non--cohesjve sediment particles at high concentrations.Past studies on the settling of discrete particles in a suspension of fine cohesjve sediment is scarcein the literature. The Sediment Research Laboratory of Tsinghua Universi… 相似文献