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901.
贝叶斯网络在水资源管理中的应用 总被引:3,自引:0,他引:3
为了解决水资源管理中具有不确定性的多目标决策问题,将贝叶斯网络方法引入水资源管理中。通过对实例系统中变量间相互关系的分析,构建描述变量间不确定性关系的贝叶斯网络模型,其中包括表示其依赖关系的有向无环图和表示其具体概率依赖程度的条件概率表,并在6个目标变量均达到预期目标的前提下进行概率推理。实例结果表明:当补偿款数额增加到500元/亩时,所有的目标变量均可达到最优,因此确定出政府应给农民补偿款的数额为500元/亩的合理水资源决策方案。贝叶斯网络以图模型的方式直观地表达了实例系统中变量之间的不确定性关系,概率推理的结果兼顾了环境效益以及农民的利益,使多个预期目标均达到了最优,有效地解决了水资源管理中具有不确定性的多目标决策问题。 相似文献
902.
高密度电法在湘西北岩溶石山区找水中的应用 总被引:15,自引:0,他引:15
湘西北岩溶石山区地质构造复杂,岩溶发育且具分布不均匀性,找水难度大,为提高含水构造的异常分辨力,各种物探方法的优化组合中,以高密度电法在确定最佳井位方面发挥了重要作用,它采集的数据量大,对异常特征反映灵敏度高,在湘西北不同的岩溶水文系统中找水,取得了成功的范例。 相似文献
903.
Sudhir Kumar Tewatia Pratima Rani Bose Asuri Sridharan Sunanda Rath 《Geotechnical and Geological Engineering》2007,25(2):239-255
It is shown that time compression curve obtained from one-dimensional consolidation curve in the laboratory may include six
phases. These are initial compression, first primary compression, transition from first primary compression to second primary
compression, second primary compression, and transition from second primary compression to creep and lastly creep. This paper
attempts to identify the quantitative beginnings and characteristics of these phases. A mathematical characteristic of all
the soils that follow primary consolidation as per Terzaghi’s one dimensional consolidation theory is derived. It is known
as the constant of primary consolidation. It is used to study the beginning of secondary consolidation and its effects on
primary consolidation. Another characteristic of soils for creep and total absence of primary compression is derived. Methods
are suggested for the determination of coefficients of Primary and Secondary consolidations and the compression index. 相似文献
904.
Water soluble components of PM10 Chongqing, China 总被引:1,自引:0,他引:1
The concentrations of water soluble ions (Na+, NH4
+, K+, Mg2+, Ca2+, NO3
-, Cl-, and SO
4
2-
) in PM10 samples collected on cellulose filters by a medium-volume cascade impactor were determined, which were obtained from three
kinds of areas in Chongqing: industrial area (Jiulongpo district), commercial and residential area (Jiangbei district) and
background area (Jinyun Mountain in the Beibei district). The results showed that except for the background site, the annual
average values of PM10 are 23% – 61% higher than the national air quality standard (GradeII) (0.1 mg/m3), even that the value of the control site is still 20% higher than American standard (0.05 mg/m3). This implied that serious pollution of fine particles occurred in Chongqing. Nine kinds of soluble ions in water of PM10 were analyzed by ion chromatography (IC) and the annual average concentrations follow the order of [SO
4
2-
] > [NO3
-] > [Cl-] > [F-], and [Ca2+] > [NH4
+] > [K+] > [Na+] > [Mg2+]. Their values were different in these areas: the industrial area > the commercial and living area > the control area. As
for NH4
+, K+, Ca2+, NO3
- and SO
4
2-
, their seasonal average concentrations show a similar variation trend: the values in spring and fall were higher than those
in summer and winter. The seasonal average concentrations of [Cl-], [F-], [Na+] and [Mg2+] are much lower than those of other ions. However, the concentrations of [Na+] changed more greatly in different seasons than those of the other three ions. Correlation coefficients showed that the three
areas have been polluted by coal smoke and dust to different extents, while some local resources of pollution should be taken
into consideration as well. 相似文献
905.
906.
907.
Shenggao CHENG Qi AN Jing HU 《中国地球化学学报》2006,25(B08):29-29
Vanadium, improving mechanism and jointing capacity of steel products, is a kind of excellent additive during steel-making and its industry gets support from national industry policy. On account of shallow buried depth and low technique request of exploitation, there is much exploitation by local people lacking system management and technique guidance in area rich in vanadium since years ago, which damages regional environment dramatically. Accordingly, taking stone coal-vanadium as an example, the paper focuses on environment impact on water environment and eco-environment caused by exploitation in open air. Impact of exploitation on surface water mainly includes mining drainage and eluviated water of stock yard. According to civilian exploitation in the area, the rock suffers man-made disturbance, therefore, water quality indicators of mining drainage like heavy metal, permanganate, CI, SO4^2-, F are able to be analogies of ground water quantity in the region since the primary component of drainage is surrounding rock ground water. Water monitoring result of local well shows as follows: pH 6.68, SO4^2- 5.76 mg/L, F- 0.005 mg/L, Fe 0.025 mg/L, Mo 8.08 μg/L, Ni 5.91 μg/L, Co 0.61 μg/L, and all of them reach corresponding standard of water quality. Ground water turns into acid mine water by oxygenation after it discharges and with the help of sulfur the acid water contains nocuous elements which permeate in groundwater and surface water arousing pollution. The value of pH in the range of standard indicates that the acidification of mine water is relatively weak in the diggings. Eco-environment damage is another aspect that cannot be ignored, it acts as: (1) peeling work and establishment construction destroy landform; (2) stack of waste soil and rock occupies amounts of land; (3) various exploitation activities like vegetation peeling, landform change will enlarge the scope or enhance the intensity of soil erosion, which destroys eco-environment by leading water and soil loss; 相似文献
908.
简要介绍了纤维束过滤器的工作原理,针对原水水质及用户对水质的要求,设计了用纤维束过滤器去除黄河水浊度的处理工艺,提出了纤维束过滤器的运行参数,分析了纤维束过滤器对黄河水浊度的去除效果. 相似文献
909.
910.