A first order mixing–condensation scheme for nocturnal stratocumulus

A simple closure scheme for nocturnal stratocumulus is proposed. The scheme is formulated in conserved variables. Cloud fraction and cloud water amount are diagnosed assuming a top-hat distribution for total water. Conversion of cloud water into rain water is parameterized in terms of cloud water and the incoming rain flux. Turbulence transport in the cloud layer is accounted for by a first-order vertical diffusion scheme with a profile-type diffusivity. The length scale corresponds to the thickness of the cloud layer. The turbulent velocity scale is directly related to the long wave radiative flux divergence in the cloud. Entrainment at cloud top is implicitly treated by extending the in-cloud mixing profile slightly beyond cloud top. The excess height is derived from the buoyancy frequency at cloud top and a radiative–convective velocity scale. The scheme is capable of simulating realistic profiles of the conserved variables and cloud parameters for a case of nocturnal stratocumulus prepared on the basis of ASTEX data.     

地下热流系统及其开发工程配置——以河南省开封市区为例

河南省开封地区在地下300~1600 m松散沉积物内,广泛分布低温(25~67℃)地下热水。根据区内50眼地热井(井深440~1580 m)资料,可分为6个亚热储层,并设计了各亚热储层的合理开发工程配置方案,以改进目前仅按用水需要的地热井布局。按照该设计方案,可使现状地热井的单井出水量平均增幅达到500~600 m3/d(80 m设计降深,除最深部亚热储层为14 m3/d外);现有49眼地热井的总出水量可由目前的43224.0 m3/d增加到设计开发工程配置方案下的150744.0 m3/d(110眼井)。通过模拟预报,研究区内地下热流系统在20 a开采期内,其水温变化很小,可以保证稳定、持续开采的要求。     

上海浦东国际机场二期航站楼工程岩土工程勘察

在深部“古河道”分布地区,桩基持力层层面起伏较大,大规模框架结构建筑,不可避免采用长短桩桩基方案。结合浦东国际机场二期航站楼工程实例,探讨此类工程勘察工作应注意的问题及解决方案。     

矿床工业指标优化时的品位统计分析及方案法结果的预测

在进行矿床工业指标优化研究中，品位的统计分析，可以了解品住值的统计分布特征，决定研究单元的划分。同时还可以预测用方案法得出的矿体平均品位、矿石储量的增长和金属储量增长的大致结果。从而提高方案法的预见性，减少进行方案试算的次数。     

三峡水库汛末蓄水时间与目标决策研究

针对三峡水库运行中存在的防洪、发电与航运之间的矛盾,研究了汛末不同蓄水方案下,三峡水库的防洪风险、发电以及上下游航运效益的变化情况;通过寻求水库防洪、发电及航运之间的相互关系,建立水库水沙联合调度模型,对三峡水库汛末蓄水时间和方式进行了多目标决策;应用加权均衡规划排序模型对非劣方案进行评价,给出了三峡水库汛末蓄水运行的最佳方案,为三峡工程正式建成后制定合理的调度运用方案提供科学依据。     

地震应急卫星通信系统实施方案

破坏性地震给人类的生命财产安全带来严重的破坏 ,地面交通及通信等基础设施也遭到极大的损坏 ,给政府震后应急救灾通信造成很大的障碍。本文旨在为震后现场应急救灾通信及灾情快速评估提供一个可行的解决方案 ,并提出在实现该方案时可能遇到的难题。     

基于五株采样提升算法的图像二叉分解与重构

提出了一种基于五株采样的提升算法，实现了一分为二的分解与重构。通过此算法可以构造非线性的形态小波变换，保持图像的几何信息。     

Seismic data compression based on integer wavelet transform

Due to the particularity of the seismic data, they must be treated by lossless compression algorithm in some cases. In the paper, based on the integer wavelet transform, the lossless compression algorithm is studied. Comparing with the traditional algorithm, it can better improve the compression rate. CDF (2, n) biorthogonal wavelet family can lead to better compression ratio than other CDF family, SWE and CRF, which is owe to its capability in canceling data redundancies and focusing data characteristics. CDF (2, n) family is suitable as the wavelet function of the lossless compression seismic data. Contribution No.04FE1019, Institute of Geophysics, China Earthquake Administration.     

An Application of Finite Volume WENO Scheme to Numerical Modeling of Tidal Current

1 .IntroductionThe development and application of hydrodynamic models to predict circulation in estuarine ,coastal ,and shelf waters has been extremely active over the past three decades (Spauldinget al .,1992 ,1994) . However , most of these models are b…     

Three-D numerical simulation of wind-driven current and density current in the Beibu Gulf

The Beibu Gulf circulation plays an imPOrtant role in the long--term water rnass transportinside the gulf. It is also closely related to the Guangxi untal water mass transport and self-purification. Hence, it is of practical imPOrtance to study the circulation in the gUlf. The cir-culation in the gUlf is very comlicated, and is rnainly gOverned by wind, water density gradi-ent, the current outside the gulf and the bathpoetry. In spring, a cold water rnass generatesln the center of the gulf…