Analytical solutions of one‐dimensional infiltration before and after ponding

This paper is a continuation of previous research, which obtained a convenient solution for arbitrary surface fluxes before ponding. By means of Fourier Transformation this has been extended to derive analytical solutions of a linearized Richards' equation for arbitrary input fluxes after surface saturation. Copyright © 2003 John Wiley & Sons, Ltd.     

含煤盆地煤储层后期改造形式及对煤层气选区影响--以华北克拉通选区为例

阐述了改造型含煤盆地煤储层被改造的两种形式；煤体结构的改造及构造煤的形成原因；后生充填物对煤层孔隙的改造及形成原因。提出了以构造煤发育程度作为改造型含煤盆地改造强度的一个指标。概述了华北克拉通盆地由中生代剪压应力转化为新生代剪张应力和拉张应力，而在盆地内形成以挤压构造为主到伸展构造为主的演化历程，及不同构造类型的区域分布，指出这种演化极易形成构造煤和后生充填物。提出将华北克拉通含煤盆地分为3种改造类型及其分布区域，分析了各自区域的煤储层物性及对煤层气开发选区的影响。提出应重视鄂尔多斯盆地侏罗纪煤层的煤层气．研究与开发．     

我国地震预报的战略建议与思考

讨论了我国地震预报面对的问题和困难。认为只有加强以形变为主的前兆观测 ,才能作出地震的短临预报。目前前兆观测的主要问题在于可信度差 ,应把重点放在仪器探头上 ,只有探头提供的信息“源”可靠了 ,后续的采集、传输、预报的“流”才会有坚实的基础。我国现在建立以形变为主的前兆台网的技术条件已经成熟 ,建议建立全国高精度的高、中、低频衔接的前兆物理信息观测网络。     

Scientific challenges and instrumentation for the International Meridian Circle Program

Earth's ecosystems and human activities are threatened by a broad spectrum of hazards of major importance for the safety of ground infrastructures,space systems...     

Correction to: Assessing real options in urban surface water flood risk management under climate change

Windblown dust originating in China and Mongolia causes health effects and agricultural damage in its source areas and causes Asian dust events in Japan. An early warning system that could be combined with weather forecasts would be helpful in preventing serious damage. However, it is difficult to specify source areas of dust with current dust modeling systems because land surface information, including vegetation coverage and land surface soil water content, is inadequate. To find and monitor dust source regions, a semi-real-time dust erodibility map was developed based on MODIS satellite data that focuses particularly on the threshold wind speed in a target area of northeast Asia including China and Mongolia (35°–50°N, 75°–120°E). The mapping system incorporates satellite data on snow cover, areas of frozen soil, surface soil water content, and vegetation cover.     

Dynamic Response and Mechanical Behaviours of Geogrid for High Earth-rockfill Dams

Geotechnical and Geological Engineering - Due to the complexity of the interaction between the geogrid and the soil interface in high earth-rock dams, the method of replacing the grid with steel...     

Preface of “Earthquake,volcanism, and physical oceanography”

Marine Geophysical Research -     

Growth and feed efficiency of juvenile shrimp Litopenaeus vannamei fed formulated diets containing different levels of poultry by-product meal

This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture ofLitopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.     

蔚县矿区岩溶水供排结合研究

本文从系统观点出发,分析了矿区岩溶水供排结合的水文地质条件,提出了以供代排,合理的规划蔚县矿区地下水资源的供排结合方案。应用有限元数值模拟与最优化技术建立供排结合水量规划的教学模型,求出了蔚县矿区最佳水源地位置和最佳的供水开采量与疏干量,实现了较好的经济效益。