东北林草交错区土壤侵蚀敏感性评价及关键因子识别

土壤侵蚀是造成东北林草交错区生态脆弱的重要原因。论文应用GIS技术,综合降水、地形、土壤可蚀性、植被覆盖等因子,分析和评价了1990—2005年研究区土壤侵蚀敏感性时空变化过程,并通过叠加排序方法定量识别关键因子。结果表明:研究区以中度敏感为主,其次是轻度和高度敏感;中度敏感地区以大兴安岭山地为主,轻度敏感地区分布在东、西部平原地区,高度敏感地区主要分布在燕山山地和大兴安岭南部山地的林草交错区;从时间变化过程看,轻度、中度敏感地区面积增加,高度敏感地区面积减少,生态环境状况总体好转;地形起伏度和植被覆盖作为研究区土壤侵蚀关键因子,起主导作用。     

基于GA与最长路径并联通路法优化通风网络图绘制

针对矿井通风网络图分支交叉的问题,基于最长路径对网络图节点分层,以遗传算法优化节点排序,主要采用堆积木的组合思想来进行层间交叉与层内交叉操作,提高层次图的质量（减少分支交叉数）,并以重心定位启发式算法来增强遗传算法的局部搜索能力,提高遗传算法的搜索质量。最后,以改进的最长路径并联通路法绘制出较优的通风网络图。     

疏浚泥固化处理的优化设计研究

将疏浚泥固化处理后的力学性质指标作为优化设计的约束条件,二次污染问题以及造价作为优化的目标函数,建立了固化处理的多目标优化设计模型。通过对固化处理进行优化设计可以解决力学性质、二次污染以及造价三者之间存在的矛盾,为建立系统的固化理论奠定了基础。并采用所建立的优化模型对大亚湾疏浚泥的固化处理进行了优化设计。     

The costs of avoiding environmental impacts from shale‐gas surface infrastructure

Growing energy demand has increased the need to manage conflicts between energy production and the environment. As an example, shale‐gas extraction requires substantial surface infrastructure, which fragments habitats, erodes soils, degrades freshwater systems, and displaces rare species. Strategic planning of shale‐gas infrastructure can reduce trade‐offs between economic and environmental objectives, but the specific nature of these trade‐offs is not known. We estimated the cost of avoiding impacts from land‐use change on forests, wetlands, rare species, and streams from shale‐energy development within leaseholds. We created software for optimally siting shale‐gas surface infrastructure to minimize its environmental impacts at reasonable construction cost. We visually assessed sites before infrastructure optimization to test whether such inspection could be used to predict whether impacts could be avoided at the site. On average, up to 38% of aggregate environmental impacts of infrastructure could be avoided for 20% greater development costs by spatially optimizing infrastructure. However, we found trade‐offs between environmental impacts and costs among sites. In visual inspections, we often distinguished between sites that could be developed to avoid impacts at relatively low cost (29%) and those that could not (20%). Reductions in a metric of aggregate environmental impact could be largely attributed to potential displacement of rare species, sedimentation, and forest fragmentation. Planners and regulators can estimate and use heterogeneous trade‐offs among development sites to create industry‐wide improvements in environmental performance and do so at reasonable costs by, for example, leveraging low‐cost avoidance of impacts at some sites to offset others. This could require substantial effort, but the results and software we provide can facilitate the process.     

多目标模糊决策模型对水环境质量的评价

水质环境质量评价宜采用多项控制指标进行综合评价。在模糊理论和考虑优先隶属度的基础上,通过实例推导出水环境质量多目标模糊决策评价图,用以说明两组或两组以上的数据或变量的相互联系,以非常直观地分析概念,讨论水质变化趋势。模型可客观地评价水域单元的各类水质指标。     

安全生产隐患排查治理工作研究

本文对安全生产隐患排查治理专项行动开展以来的成效及问题进行研究，探讨通过采取建章立制、落实责任、注重科学、讲求实效等措施，建立完善安全生产隐患排查治理工作的体制、机制，使安全生产隐患排查治理工作进一步制度化、规范化、经常化，有效遏制重特大事故的发生，促进安全生产状况持续稳定好转。     

防雷接地装置腐蚀影响因素的层次分析法

防雷接地装置是保证防雷系统正常运行的基础,然而,它不可避免会受到土壤的腐蚀。首先对防雷接地装置腐蚀机理进行了论述;其次通过整理、分析文献资料,合理选取影响防雷接地装置腐蚀的主要因素;然后根据腐蚀因素参与腐蚀的程度,构建层次分析模型,利用模型对腐蚀因素进行定量分析,界定出影响因素对防雷接地装置腐蚀影响的权重值;最后对腐蚀因素进行综合排序。研究表明,影响防雷接地装置腐蚀的最主要因素为pH值、土壤电阻率和含水量,这为制定经济合理、安全可靠的防雷接地装置腐蚀防护措施提供了科学依据,具有实际工程应用价值。     

Parameter Uncertainty Reduction for SWAT Using Grace,Streamflow, and Groundwater Table Data for Lower Missouri River Basin1

Abstract: This study incorporates the newly available Gravity Recovery and Climate Experiment (GRACE) water storage data and water table data from well logs to reduce parameter uncertainty in Soil and Water Assessment Tool (SWAT) calibration using a SUFI2 (sequential uncertainty fitting) framework for the Lower Missouri River Basin. Model evaluations are performed in multiple stages using a multiobjective function consisting of multisite streamflow and GRACE water storage data as well as a groundwater component. Results show that (1) a model calibrated with both streamflow and GRACE data simultaneously can maintain the water balance for the whole basin, but may improperly partition surface flow and base flow. Additional inclusion of the groundwater constraint can significantly improve the model performance in groundwater hydrological processes. In our case, the estimation of specific yield of shallow aquifers has been increased to 10^?2 from previous much underestimated level (<10^?3). (2) The daily streamflow data are needed to confine the parameters related to water flow in channels such as the Manning’s coefficient, which are less sensitive to the monthly simulations. (3) Parameters are nonuniformly sensitive for different goal variables, and thus, proper specification of a prior distribution of parameters may be the key factor for global optimization algorithms to obtain stable and realistic model performance.     

Cost effective environmental control technology for utilities

On September 24, 1998, new regulations announced by the US EPA require 22 eastern states plus the District of Columbia to develop state implementation plans to reduce ground-level ozone through the reduction of nitrogen oxide (NOx) emissions (Cooper, 1998). This plan calls for a 28% NOx cut in the summer time (1.2 million tons) by 2007. This calls for utilities to develop new, efficient, and robust post-combustion NOx control technologies. A new environmental control technology called low temperature oxidation (LTO) system, which can reduce NOx emissions below measurable levels (i.e. 2 ppm using process analyzers) at low temperature (125-325 °F), was awarded the best available control technology and the lowest available emission reduction technology by the US EPA in April 1998. Ozone is employed to oxidize nitric oxide (NO) to dinitrogen pentoxide (N₂O₅) at a low temperature in an oxidizer, which is then easily absorbed by water in a scrubber. Bench scale and pilot plant tests have shown that the LTO process can almost completely remove the NOx emissions (i.e. NOx emissions are below levels measurable using process analyzers). This proved that the LTO system is an attractive process to meet the stricter NOx regulations. There are multiple benefits of the LTO system besides removal of NOx emissions, includes reduction of SOx and CO emissions, and no secondary air emissions (NH₃, N₂O). In order to obtain minimum NOx emissions, extra ozone needs to be supplied. The cost of the process also increases nonlinearly as emissions decrease. This poses a challenging multiobjective optimization problem where emissions like NOx and SOx need to be minimized, while minimizing the system cost as well as extra ozone. This problem is addressed using a new and efficient multiobjective optimization framework. This framework will provide designs that are cost effective as well as environmentally friendly.     

A MULTILEVEL MODEL AND ALGORITHM FOR SOME MULTIOBJECTIVE PROBLEMS1

This paper presents a solution method for a class of multiobjective problems characterized by a hierarchical structure of decisionmaking and a large number of alternatives. The method, consisting of a multilevel problem formulation and an interactive algorithm, has distinct advantages for identifying preferred solutions to problems having those characteristics. The method is illustrated to a problem involving waste water treatment in the chemical industry.