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排序方式: 共有231条查询结果,搜索用时 46 毫秒
1.
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
2.
LEE Hyun Koo 《《地质学报》英文版》2003,77(1):116-124
A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion 相似文献
3.
XU Guobin Senior Research Engineer Tianjin Institute of Hydroelectric Investigation Design Research Ministry of Water Resources. Dongting Road Hexi District Tianjin P R. China. BAI Shilu Senior Research Engineer Tianjin Institute o 《国际泥沙研究》1997,(3)
I.INTRODUCTIONReseri,oirsonoverloadedriverswillreachthestateofrelativeequilibriumwithcontinuousdevelopmentofsedimentation.Insuchcase,thereisdePOsitinfrontofthedam.Thereforethesiltpressureonthedambodyisconsiderablylarge.Sedimentationelevationinfrontofthedamisoneofthefactorsofcalculatingthesiltpressure.Inaddition,tokeeplong-termworkingstorageinreservoif,itisnecessarytoinstallbottomoutlets.Asthereisapressureconduitinfrontoftheoperatinggateofthebottomoutlet,thesedimelltenteredtheconduitwill… 相似文献
4.
八卦庙金矿床的绿泥石特征及成岩成矿意义 总被引:6,自引:1,他引:6
绿泥石是八卦庙大型金矿床的主要热液蚀变矿物,本文系统地研究了绿泥石的产状、矿物学、化学成分等特点。在此基础上应用Walshe的绿泥石六组分热力学模型计算了绿泥石形成的物理化学条件:形成温度247.6~335.1℃,lgfo2值为一27.35~37.99,lgfs2的值是-7.46~-13.02,与根据成矿期石英包裹体所计算的值相近。 相似文献
5.
Seasonal Variation of the East Asian Subtropical Westerly Jet and Its Association with the Heating Field over East Asia 总被引:3,自引:0,他引:3
The structure and seasonal variation of the East Asian Subtropical Westerly Jet (EAWJ) and associations with heating fields over East Asia are examined by using NCEP/NCAR reanalysis data. Obvious differences exist in the westerly jet intensity and location in different regions and seasons due to the ocean-land distribution and seasonal thermal contrast, as well as the dynamic and thermodynamic impacts of the Tibetan Plateau. In winter, the EAWJ center is situated over the western Pacific Ocean and the intensity is reduced gradually from east to west over the East Asian region. In summer, the EAWJ center is located over the north of the Tibetan Plateau and the jet intensity is reduced evidently compared with that in winter. The EAWJ seasonal evolution is characterized by the obvious longitudinal inconsistency of the northward migration and in-phase southward retreat of the EAWJ axis. A good correspondence between the seasonal variations of EAWJ and the meridional differences of air temperature (MDT) in the mid-upper troposphere demonstrates that the MDT is the basic reason for the seasonal variation of EAWJ. Correlation analyses indicate that the Kuroshio Current region to the south of Japan and the Tibetan Plateau are the key areas for the variations of the EAWJ intensities in winter and in summer, respectively. The strong sensible and latent heating in the Kuroshio Current region is closely related to the intensification of EAWJ in winter. In summer, strong sensible heating in the Tibetan Plateau corresponds to the EAWJ strengthening and southward shift, while the weak sensible heating in the Tibetan Plateau is consistent with the EAWJ weakening and northward migration. 相似文献
6.
Xiangyang Li Jianxin Yuan British Geological Survey West Mains Road Edinburgh EH LA UK. Formerly at British Geological Survey now at PGS Inc. Richmond Avenue Suite Houston TX USA. 《应用地球物理》2005,2(1)
我们业已研发了计算各向异性、非均质介质中P- SV转换波(C-波)的转换点和旅行时的新理论。据此 可以利用诸如相似性分析、迪克斯模型建模、克契 霍夫求和等常规方法来完成各向异性的处理和各向 异性处理,并使各向异性的处理成为可能。这里将 我们的新发展分作两部分来介绍。第一部分为理 论,第二部分为对速度分析和参数计算的应用。第 一部分理论包括转换点的计算和动校正的分析。 相似文献
7.
雨滴谱仪与风廓线雷达反射率对比试验 总被引:2,自引:2,他引:0
针对风廓线雷达估算的反射率数据需要进行验证。开展雨滴谱仪与风廓线雷达反射率对比试验,通过两种不同探测设备观测数据的对比,以验证风廓线反射率数据的可靠性和可用性。结果表明:确定了以风廓线低模360~1440 m采样体积内的反射率与3 min雨滴谱反射率数据对比方法能最大程度的减少时空差异;在雨滴谱仪反射率小于40 dBz时,对应的风廓线雷达反射率数据是可靠和可用的;同时由于风廓线雷达有限的动态范围造成反射率低估的现象,使得风廓线雷达反射率在大气垂直结构以及微物理特性等方面应用受到一定的局限性。 相似文献
8.
轻非水相液体(light non-aqueous phase liquid,LNPAL)在地下介质中的运移分布与残余捕获受多种因素影响和控制。LNAPL污染场地概念模型中一般视LNAPL从地表泄漏后穿过包气带至潜水面。然而地下介质的非均质性与包气带含水量的空间变异分布可形成复杂的LNAPL污染源区结构,LNAPL可能无法到达潜水面,而在毛细水带蓄积。文章基于数值模型综合分析了LNAPL泄漏量、介质非均质性与含水量空间变异分布、潜水面周期性变化等多种因素对LNAPL污染源区结构的影响。研究表明:(1)当泄漏量较大时,LNAPL可运移至潜水面;(2)当泄漏量较小时,对于上粗下细的层状非均质条件,LNAPL可能在毛细水带边缘发生蓄积,无法到达潜水面;(3)包气带中黏土透镜体并非都是LNAPL运移的阻碍,LNAPL可以穿透低含水量的黏土透镜体,只有高含水量的黏土透镜体才对LNAPL的入渗有阻碍作用;(4)潜水面周期性变化将导致污染范围扩大。 相似文献
9.
Shangbin Chen Zhuo Gong Xueyuan Li Huijun Wang Yang Wang Yingkun Zhang 《地学前缘(英文版)》2021,12(6):192-208
Fine characterization of pore systems and heterogeneity of shale reservoirs are significant contents of shale gas reservoir physical property research.The research on micro-control factors of low productivity in the Qiongzhusi Formation(Fm.)is still controversial.The lower Cambrian Qiongzhusi Fm.in the Qujing,Yunnan was taken as the object to investigate the influence of mineral compositions on the phys-ical properties of the reservoir and the heterogeneity of shale,using the algorithm to improve the char-acterization ability of Atomic Force Microscopy(AFM).The results showed that:(1)The pores are mainly wedge-shaped pores and V-shaped pores.The pore diameter of the main pore segment ranges from 5 to 10 nm.Mesopores are mainly developed in the Qiongzhusi Fm.shale in Well QD1,with the average pore diameter of 6.08 nm.(2)Microscopic pore structure and shale surface properties show strong hetero-geneity,which complicates the micro-migration of shale gas and increases the difficulty of identifying high-quality reservoirs.(3)The increase of clay mineral content intensifies the compaction and then destroys the pores.Conversely,brittle minerals can protect pores.The support and protection of brittle minerals to pores space depend on their content,mechanical properties and diagenesis.(4)Compression damage to pores,large microscopic roughness and surface fluctuations and strong pore structure heterogeneity are the reasons for the poor gas storage capacity of the Qiongzhusi Fm.,which will lead to poor productivity in the Qiongzhusi Fm. 相似文献
10.
王桥 《武汉大学学报(信息科学版)》1993,(4)
本文提出了一种新的实用地图数据检索方法——“放大镜”式地图数据检索,建立了相应的软件系统,并讨论了该方法的数学基础、软件的特点,还给出了应用实例。 相似文献