充填型溶洞中地下工程支护结构设计及施工技术研究

以某大型地下工程的设计、施工、监测为实例背景,系统介绍了富水、充填型溶洞的处理方法。在超前地质预报工作的基础上,结构设计采用超前注浆堵水、初期格栅钢架喷砼网支护、二次现浇钢筋砼衬砌的复合式衬砌方案。掘进采用中隔墙法开挖,并设置泄水洞辅助减压,取得了较好的效果。     

PREDICTABILITY OF SURFACE WATER POLLUTION LOADING IN PENNSYLVANIA USING WATERSHED‐BASED LANDSCAPE MEASUREMENTS1

ABSTRACT: We formally evaluated the relationship between landscape characteristics and surface water quality in the state of Pennsylvania (USA) by regressing two different types of pollutant responses on landscape variables that were measured for whole watersheds. One response was the monthly exported mass of nitrogen estimated from field measurements, while the other response was a GIS‐modeled pollution potential index. Regression models were built by the stepwise selection protocol, choosing an optimal set of landscape predictors. After factoring out the effect of physiography, the dominant predictors were the proportion of “annual herbaceous” land and “total herbaceous” land for the nitrogen loading and pollution potential index, respectively. The strength of these single predictors is encouraging because the marginal land cover proportions are the simplest landscape measurements to obtain once a land cover map is in hand; however, the optimal set of predictors also included several measurements of spatial pattern. Thus, for watersheds at this general hierarchical scale, gross landscape pattern may be an important influence on instream pollution loading. Overall, there is strong evidence that using landscape measurements alone, obtained solely from remotely sensed data, can explain most of the water quality variability (R²= approx. 0.75) within these watersheds.     

生态环境空间数据的多尺度集成方法

空间数据集成是解决异构网络环境信息系统间空间数据交换、传输和共享、数据互操作的有效方法。笔者在分析生态环境数据特征和生成机理以及集成原理基础上 ,提出了生态环境空间数据的空间多尺度集成方法 ,并构建了基于面向应用目标的生态环境空间数据集成系统框架和运行过程机制。 更多还原      

Differential treatment within sports teams,leader–member (coach–player) exchange quality,team atmosphere,and team performance

Using the leader–member exchange (LMX) theory as a theoretical framework, the present study focused on the occurrence of differential treatment by leaders on social and task‐related issues within teams. It was investigated whether team members' perceptions of the frequency and degree of social and task‐related differential treatment by the leader were associated with their evaluation of team atmosphere and team performance, in addition to the effects of the quality of their own working relationship with the leader (LMX quality). The context of this study consisted of interdependent sports teams. The participants were 605 players belonging to 69 amateur sports teams playing various team sports such as soccer, hockey, and basketball. Social differential treatment was negatively associated with team atmosphere and unrelated to team performance. In addition, it was found that the two forms of task‐related differential treatment included in this study were unrelated to team atmosphere and were differently associated with team performance. The results are discussed with reference to the existing leadership literature. Copyright © 2010 John Wiley & Sons, Ltd.     

广西龙布排泥库地下水多元示踪试验研究

以具有复杂水文地质背景的广西平果铝业公司龙布排泥库为研究区．采用钼酸铵、萤光素钠和氯化锌三种试剂．综合考虑各种水文地质条件和其它影响因素．在测区48km^2范围内,布置投放点3个．接收点19个,进行地下水多元示踪试验,为该尾矿库的设计与建设提供必要的水文地质依据,分析库内与库外的地下水水力联系情况,尤其库内与布见水库的水力联系情况,并计算地下水流速,确定地下水流向的主导方向,对于评价该尾矿库对布见水库水源的污染情况具有重要意义。     

国外光伏发电并入智能电网发展探讨

智能电网是未来电网发展的主要趋势。随着人们对环境保护的重视,如何将风能、太阳能等可再生能源大规模接入电网已经成为智能电网下一阶段的研究方向。介绍了国外光伏发电技术发展,概述了国外对光伏发电并入智能电网的最新研究,提出了光伏并网发电面临的问题以及相关建议,为我国未来光伏并网发电的实施提供参考。     

电网应急演练方案编制规范化过程及评估方法研究

电网应急演练方案编制过程的不规范,对演练评估的不重视,严重影响应急演练的效果。根据电网应急演练工作实情,从演练目标的确定、演练的情景设计、演练过程设计、演练评估方案设计、演练方案文件的编写五个环节分析应急演练方案编制规范化过程的要点。以初始场景、主事件、详细事件三个层次设计演练情景,引进情景构建思想,采用“情景-任务-能力”路线开展演练评估,并以大面积停电事件为例进行示范应用,为电网应急演练方案编制规范化建设及评估提供思路。     

Landscape and Agricultural Patterns in Rural Areas: a Case Study in the Brionne Basin, Normandy, France

Landscape changes over a period of 25 years were assessed for a catchment basin in Normandy, France. Landscape attributes, i.e. land use, land cover and natural habitat, were obtained from aerial photographs (1964, 1989) and soil maps, to define a landscape typology. Data were aggregated on a 500 m×500 m grid system and treated by multivariate analysis. Results of these analysis show that this rural landscape has undergone changes in landcover (mainly grassland receding to crop) as well as changes in spatial structure (mainly increase of plot size and uniformisation). These changes were related to a typology of farms (realised by multivariate analysis of a field survey on the 38 registered farms of the site). Results suggest that (i) farms with a narrow range of production, i.e. specialised farms, are located on a narrow range of environmental conditions and are associated with stable landscapes, while (ii) farms with a broader range of production (i.e. polyculture) are distributed more widely throughout the landscape, and are mostly associated with the landscape changes.     

A multi media load model for the Baltic Sea

The background of this work is the international decision process with regard to the selection of chemicals to be assessed with priority. In order to stress the precautionary principle, mass flows were analysed rather than concentrations, threshold values, etc., as preferred by the chemical legislation (which still excludes the marine area). Lindane, hexachlorobenzene (HCB), trichloroacetic acid and its sodium salt, medium-chained chlorinated paraffins and tributyltin (TBT) were selected due to their great relevance for the marine area. Trichloroacetic acid is an interesting model compound on account of its accidental formation by degradation of volatile chlorinated hydrocarbons and during chlorination processes. In addition, a hypothetical compound was modelled, representing a highly water-soluble substance with low vapour pressure. The balancing area is the Baltic Sea and its catchment area. In order to model the substance flows, the 'Input/Output-load model' has been developed. The model quantifies the shift and the distribution of a yearly load of the substance investigated from the terrestrial-limnic into the marine compartment (Baltic Sea). Water-soluble substances, which are usually considered to be of no concern, may enter the sea in great amounts and, if not degradable, remain there. It turned out to be necessary to take into account remobilisation, unintended formation and point as well as line-sources.     

Automatic Calibration of Hydrologic Models With Multi‐Objective Evolutionary Algorithm and Pareto Optimization1

Abstract: In optimization problems with at least two conflicting objectives, a set of solutions rather than a unique one exists because of the trade‐offs between these objectives. A Pareto optimal solution set is achieved when a solution cannot be improved upon without degrading at least one of its objective criteria. This study investigated the application of multi‐objective evolutionary algorithm (MOEA) and Pareto ordering optimization in the automatic calibration of the Soil and Water Assessment Tool (SWAT), a process‐based, semi‐distributed, and continuous hydrologic model. The nondominated sorting genetic algorithm II (NSGA‐II), a fast and recent MOEA, and SWAT were called in FORTRAN from a parallel genetic algorithm library (PGAPACK) to determine the Pareto optimal set. A total of 139 parameter values were simultaneously and explicitly optimized in the calibration. The calibrated SWAT model simulated well the daily streamflow of the Calapooia watershed for a 3‐year period. The daily Nash‐Sutcliffe coefficients were 0.86 at calibration and 0.81 at validation. Automatic multi‐objective calibration of a complex watershed model was successfully implemented using Pareto ordering and MOEA. Future studies include simultaneous automatic calibration of water quality and quantity parameters and the application of Pareto optimization in decision and policy‐making problems related to conflicting objectives of economics and environmental quality.