特殊人工环境对武器装备的危害

给出了在战争条件下特殊人工环境的定义,并举例说明了人工环境在古今战役中的应用,具体阐述了烟尘环境、核环境、电磁辐射环境和生化有毒沾染环境等4种特殊人工环境对武器装备各方面的危害,最后指出了在现代高技术战争中研究特殊人工环境对武器装备危害的重要性和必要性.     

基于LS-SVM的供水管网安全性评价方法研究

为评价城市供水管网的安全性,保障其正常运行,笔者基于多元分类最小二乘支持向量机(LS-SVM)的方法,在对城市供水管网安全运行影响因素总结与分析的基础上,构建供水管网安全性评价的指标因素集与评价模型,通过对有限的经验数据的学习,建立供水管网安全性与其影响因素之间的非线性关系。运用该模型进行实例仿真模拟,通过与实际安全等级及BP神经网络模型预测安全等级之间的对比表明:基于LS-SVM的供水管网安全性评价方法具有较高的精度,正确分类率可以达到83.33%。     

基于相空间神经网络耦合模型的径流降尺度分析

基于混沌理论和神经网络理论,研究水文科学的尺度问题,将混沌神经网络分析方法应用于径流的降尺度分析。首先通过对年径流量分解到月径流量的分解系数的分析,证明了分解系数具有混沌特性;其次利用相空间BP神经网络模型对分解系数进行预测,并根据预测结果进行月径流量的降尺度计算。实例研究表明,用神经网络拟合分解系数相空间的相点演化非线性关系和用相空间神经网络模型对径流作降尺度分析是可行的。     

黄海南部近岸海域水质评价

基于2005年1月黄海南部近岸海域水质现场监测结果,采用单因子指数评价法、富营养化指数（E）评价法、有机污染指数（A）评价法对该海域水质状况进行现状评价,结果表明：pH值、DO、无机氮、CODMn均达《海水水质标准》）GB3097—1997）中一类水质标准;PO4^3- -P、BOD5仅达二类水质标准,且各监测站点超标率都已高于50％;43％监测站点E〉1,呈现明显富营养化,其余各站点E值也已接近1,处于富营养化临界状态;A值的范围为0．65～1．22．有57％的站点A〉1,有机污染巳相对较严重。总体来看,该海域水质已受到污染。必须对富营养化和有机污染加以控制。     

Monitoring of Distribution Water Qualities Under Various Source Water Blending

The main goal of this large-scale pilot distribution study was to systematically investigate the impacts of blending different source waters on distribution water qualities. The principal source waters investigated were conventionally treated ground water (G1), surface water processed by enhanced treatment (S1), and desalted seawater by reverse osmosis membranes (RO). Due to the nature of raw water quality and associated treatment processes, G1 water had high alkalinity, while S1 and RO sources were characterized as high sulfate and high chloride waters, respectively. One year of pilot pipe study demonstrated that water quality was significantly deteriorated by increased color when source water blends with characteristics different from historic groundwater were introduced to pipe distribution systems. Elevated color was associated with release of iron corrosion products, mainly from aged unlined cast iron pipes. Iron release increased significantly when exposed to RO and S1 waters: that is, the greater iron release was experienced with alkalinity reduced below the background of G1 water. Lead and copper release to water, on the other hand, enhanced with the application of RO and G1 waters, respectively.     

新型钛铜复合管在流动海水中的腐蚀行为

设计了循环管路,通过海水管路冲刷腐蚀试验,对比研究了新研制的爆炸焊钛铜复合管与铜管的耐海水腐蚀性能。宏观和微观腐蚀形貌以及微观成分分析表明,在海水冲刷作用下,铜管受到腐蚀,微观表面呈现颗粒状形貌,钛铜复合管无腐蚀,表现出了良好的应用性能。     

人工神经网络方法在我国环境预测中的应用

从环境预测的模型适用性出发,提出用人工神经网络技术进行环境预测的新思路,建立了环境预测的多层神经网络模型,利用最近１２年（１９８１－１９９２）的环境经济数据对２０００年环境指标进行了预测,并根据预测结果对未来的环境对策进行了分析。     

ANADROMOUS SALMONID RECOVERY IN THE UMATILLA RWER BASIN,OREGON: A CASE STUDY1

ABSTRACT: The Umatilla River Basin Fisheries Restoration Plan was initiated in the early 1980s to mitigate salmonid losses caused by hydroelectric development and habitat degradation. The objectives are to enhance the abundance of endemic steelhead and reintroduce extirpated chinook and coho salmon. The project prompted collaborative effort among federal, state, and tribal agencies, and local water users. It has incorporated habitat restoration, flow enhancement, fish passage improvements, and population supplementation through artificial production. Water exchanges have successfully increased minimum flows during spring and fall migration. While flows remain depressed compared to historic conditions, there is potential for improved habitat, passage, and homing. The mean adult‐to‐adult return rate of hatchery‐reared steelhead exceeded replacement and that of the naturally‐spawning population. Although the smolt‐to‐adult survival rates of hatchery‐reared fish fluctuate, salmonid escapement has increased in recent years, permitting steelhead and spring chinook harvest. Enumeration of potential spawners and observed redds reveals an increase in natural production of all supplemented species. Comparison of hatchery‐reared and naturally‐spawning steelhead populations revealed differences in life history characteristics (in age composition and sex ratios) though run timing and genetic stock compositions of the two components of the populations have not differed. Sustained monitoring is needed to determine benefits of integrating habitat restoration and artificial production in restoring salmonid populations.     

南方海涂海水灌溉库拉索芦荟的试验研究

在海南海涂沙滩(非耕地资源)对药用植物库拉索芦荟进行海水灌溉试验,设6种处理,淡、海水配比分别为A1(CK):100∶0;A2:90∶10;A3:75∶25;A4:50∶50;A5:25∶75;A6:0∶100。结果表明:①用一定浓度范围的海水灌溉时,库拉索芦荟苗期返青系数、根的综合生长量等植物生态指标为处理A3>A2>A1,超过一定海水浓度后则递减;连续3年的田间试验表明,芦荟叶片鲜重、干重A1、A2、A3三种处理间没有显著差异,而根干重A3显著高于A1,A4比A1处理叶片鲜重、干重减产均在20%以内,表明海水灌溉库拉索芦荟是可行的。②海水灌溉明显推迟芦荟从营养生长向生殖生长的转化时期,随着海水比例的增加,抽苔期明显推迟。③各种处理海水灌溉的沙滩深度在0～10cm范围内,盐分含量随深度迅速下降,10cm以下下降幅度变缓;经3年的海水灌溉试验,海涂沙滩在未作任何人为调控措施下,0～50cm沙滩含盐量仍在0.3%范围内。     

AN ENGINEERING ECONOMIC ANALYSIS OF A PROGRAM FOR ARTIFICIAL GROUNDWATER RECHARGE1

This study describes and demonstrates two alternate methods for evaluating the relative costs and benefits of artificial groundwater recharge using percolation ponds. The first analysis considers the benefits to be the reduction of pumping lifts and land subsidence; the second considers benefits as the alternative costs of a comparable surface delivery system. Example computations are carried out for an existing artificial recharge program in Santa Clara Valley in California. A computer groundwater model is used to estimate both the average long term and the drought period effects of artificial recharge in the study area. For the example problem, the benefits of reduced average annual pumping lifts and reduced incremental subsidence are greater than the total costs of continuing the existing artificial recharge program. Benefits for reduced subsidence are strongly dependent on initial aquifer conditions. The second analysis compares the costs of continuing the artificial recharge program with the costs of a surface system which would achieve the same hydraulic effects. Results indicate that the costs of artificial recharge are considerably smaller than the alternative costs of an equivalent surface system. In evaluating a particular program, consideration should also be given to uncertainties in future supplies and demands for water as well as to the probability of extreme events such as droughts.