细粒级掺杂石墨材料的制备及其出气特性的研究

通过球磨分散方法制备了细粒级掺杂石墨 ,采用SEM、EDX、TEM、XRD等手段分析了材料微观结构 ,并对其性能作了初步研究。研究表明 :当原始粉粒径小于 10 0nm时 ,材料具有高的热导率和优良的物理机械性能 (抗弯强度为 116MPa) ,与粗晶石墨材料相比 ,细晶石墨材料在电子束辐照前的出气性能与其基本相同。而辐照之后 ,细晶石墨材料释放的H2 、H2 O、CO ,特别是CO2 的量远远少于粗晶石墨材料释放的量     

Application of exergy as thermodynamic indicator in ecology

We introduce a modified form of exergy named eco-exergy as an ecological indicator. Exergy of detritus and of various organisms are found based upon the definition of eco-exergy. Eco-exergy measures a system's deviation from chemical equilibrium. It is, therefore, crucial to find the concentration of detritus and the various organisms at chemical equilibrium which is possible by the calculation of the probability to form detritus and the various organisms by chemical equilibrium. It implies that the probability to form proteins with the right amino acid sequence must be determined by the use of the amount of coding genes. It is stressed that what we determine by this method of exergy calculation is a relative eco-exergy index. It is not possible to find the eco-exergy of entire ecosystems, because they are far too complex to allow us to know all the details of an ecosystem. The eco-exergy indices have been found in a few cases to demonstrate the usefulness of the method and to show how the exergy indices can be translated to applicable ecological information.     

江坪河高面板堆石坝三维非线性结构有限元分析

采用三维非线性有限单元法对江坪河面板堆石坝施工填筑期和水库蓄水运行期的应力变形进行模拟计算，研究引用不同的堆石料参数（水布垭面板坝和天生桥一级电站面板坝材料参数）和不同的接触单元模型，分析不同时期产生的坝体应力和变形，且对江坪河面板坝与水布垭和天生桥面板的应力变形特性做了对比分析，为该坝的进一步优化设计提供了有益的建议。     

智能主体主要理论的综述与分析

智能主体是发展迅速的一个研究热点 ,其理论也纷繁多样。分别以如何解决单智能主体和多主体系统的核心问题—资源有限智能问题和主体间协调问题为线索对两方面现有的理论分类总结 ,从而勾勒出了当前该领域理论研究方面的一个大致的轮廓。     

国外沙丘研究综述

本文对国外沙丘的研究历史进行了简要回顾 ,就沙丘形态学、沙丘沉积学和沙丘动力学作了扼要评述 ,并对今后研究的趋势进行了探讨。     

门限自回归模型及其在水文随机模拟中的应用

为了客观描述日流量变化的非线性特性 ,将一种非线性时序模型——门限自回归模型引入日流量随机模拟。根据我国金沙江流域屏山站观测资料建立了日流量随机模拟的门限自回归模型。实用性检验结果表明 ,该模型用于模拟日流量过程是可行的 ,成果实用。这种尝试为日流量随机模拟提供了一种考虑日流量非线性变化特性的新模型。     

凹凸棒石粘土对中低放核素Sr、Cs的吸附研究

通过实验研究 ,讨论了经不同方法改性处理的凹凸棒石粘土对锶铯的吸附作用。研究表明凹凸棒石粘土对铯的吸附能力优于锶。特别是经改性剂处理的凹凸棒石粘土 ,在碱性、氧化条件下对锶铯的吸附更为显著     

ENDOW (efficient development of offshore wind farms): modelling wake and boundary layer interactions

While experience gained through the offshore wind energy projects currently operating is valuable, a major uncertainty in estimating power production lies in the prediction of the dynamic links between the atmosphere and wind turbines in offshore regimes. The objective of the ENDOW project was to evaluate, enhance and interface wake and boundary layer models for utilization offshore. The project resulted in a significant advance in the state of the art in both wake and marine boundary layer models, leading to improved prediction of wind speed and turbulence profiles within large offshore wind farms. Use of new databases from existing offshore wind farms and detailed wake profiles collected using sodar provided a unique opportunity to undertake the first comprehensive evaluation of wake models in the offshore environment. The results of wake model performance in different wind speed, stability and roughness conditions relative to observations provided criteria for their improvement. Mesoscale model simulations were used to evaluate the impact of thermal flows, roughness and topography on offshore wind speeds. The model hierarchy developed under ENDOW forms the basis of design tools for use by wind energy developers and turbine manufacturers to optimize power output from offshore wind farms through minimized wake effects and optimal grid connections. The design tools are being built onto existing regional‐scale models and wind farm design software which was developed with EU funding and is in use currently by wind energy developers. Copyright © 2004 John Wiley & Sons, Ltd.