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排序方式: 共有256条查询结果,搜索用时 36 毫秒
21.
MYUNGA-KALUMBWE(以下简称MKM)铜钴矿区位于世界第三大铜矿带--南非赞比亚-刚果(金)矿带的北西部,是一个具有百年开采历史的老矿区。MKM矿床为大型层控型矿床,主矿体位于倒转背斜轴部,受区域浅变质作用和后期改造而富集。矿体主要赋存于加丹加岩系罗安群内一套受了区域变质作用的陆源碎屑岩和白云岩地层中。通过对区域成矿地质背景和MKM矿床地质特征的分析,总结了控矿地质因素、矿床成因类型等。 相似文献
22.
优选渤海湾地区的2个大型海盐生产企业,针对制盐的各工艺流程中Li的含量变化进行研究。研究结果表明:在制盐工艺中,从海水至老卤锂明显逐步浓缩,2个盐场老卤中LiCl浓度分别为9727 mg/L和13815 mg/L,接近卤水锂矿边界品位;海水盐化工生产过程中盐类结晶对Li+的吸附效应不明显。根据我国海盐产量与渤海湾地区的采样数据推算,2013年全国海水盐场全年生产的老卤中锂金属量为45595 t,折合成碳酸锂当量为2 43023 t。由此可见,海盐场年处理海水中锂含量较高,另外含锂的苦卤老卤较易集中,单一提锂工艺具有通用性,因此我国海盐场卤水中锂资源的提取前景广阔。另外,直接从海水中提锂工艺也应是今后的主攻方向,一旦突破技术成本,直接从海水提锂产业化前景无限。 相似文献
23.
在剖析水污染物总量控制问题的基础上,将和谐论引入水污染物总量控制研究中,诠释水污染物总量控制的和谐问题。为保证水污染物总量控制的成功实施,建立基于和谐论的水污染物总量控制模型,从和谐的角度分析水污染物总量控制措施的制定,以改善进入水体的污染物总量与水体纳污能力之间的不和谐关系。最后将建立的模型应用于武汉市汤逊湖流域中,应用结果表明该模型可以较好地反映流域水污染物总量控制问题中"统一"与"分歧"的辩证关系,有助于解决水污染物总量控制和污染负荷分配问题,为水体污染防治提供技术支撑。 相似文献
24.
25.
《Expert systems with applications》2008,34(4):1054-1062
This paper intends to an integrated view of implementing automated diagnostic systems for breast cancer detection. The major objective of the paper is to be a guide for the readers, who want to develop an automated decision support system for detection of breast cancer. Because of the importance of making the right decision, better classification procedures for breast cancer have been searched. The classification accuracies of different classifiers, namely multilayer perceptron neural network (MLPNN), combined neural network (CNN), probabilistic neural network (PNN), recurrent neural network (RNN) and support vector machine (SVM), which were trained on the attributes of each record in the Wisconsin breast cancer database, were compared. The purpose was to determine an optimum classification scheme with high diagnostic accuracy for this problem. This research demonstrated that the SVM achieved diagnostic accuracies which were higher than that of the other automated diagnostic systems. 相似文献
26.
《Energy and Buildings》2005,37(3):189-202
Experimental data recorded for a heating, ventilating, and air conditioning system showed that the daily heated water loop energy calculated by summing the hourly-averaged loop heat transfer for the heated water loop is almost 35% higher than the sum of the daily energy consumed by variable air volume hydronic reheat coils in each zone. The main reason for this difference was attributed to the time delay of the loop return water temperature caused by the water traveling along the loop. This study examines methods to evaluate the heated water loop energy when there are time varying conditions. Data for a heated water loop are used to demonstrate the effects of the time delay on the evaluation of the loop energy. A pipe heat transfer model characterizing the transient response of a fluid flowing through a single pipe is developed to examine the effects of time varying conditions on the pipe thermal response. Based on the pipe heat transfer model, a loop model is constructed to simulate the actual loop with multiple hydronic reheat coils. The comparisons of the simulation results with the data indicate that the loop model is capable of predicting the loop return water temperatures and loop heat transfer based on data. 相似文献
27.
以永定河山区为算例,对北方地区的水资源模拟进行了研究。首先运用分布式水文模型计算了天然径流量,其次通过用水户的供、用、耗、排关系建立了水资源模拟模型,并计算了主要控制断面的径流量和用水户的需水量以及用水量、缺水量以及供水工程的蓄水量、供水量、弃水量等指标。通过模拟计算表明,干流河道控制断面的计算径流量与实测径流量基本吻合,支流河道有一定的偏差。 相似文献
28.
结合天津市海河综合开发改造工程大沽路、会师广场、七马路地下排水泵站工程,分析城市排水泵站产生臭气的主要原因,阐述生物过滤、高能离子、天然植物液等除臭方法和适用条件。结合该项目建设、运行、管理等特点,采用高能离子除臭工艺对恶臭气体进行治理,指出泵站建设形式、除臭工艺流程及各系统构造,并严格控制气体排放指标,达到了较好的除臭效果。 相似文献
29.
电网往往需要配备足够的旋转备用容量以支撑风电的接纳,当旋转备用容量不足时,风电接入容量将受限或会导致更严重的污染物排放。提出了电网向下调峰容量不足时风电增发引起的"挤出效应"概念,构建了一种风电节能减排效益评估方法,用于评估为满足系统负荷需求风电接入所带来的全系统发电能源节约和相应的温室气体、污染物减排等效益,并分析评价了既有电网不同调峰容量水平对风电接入容量的影响。通过算例对所接入风电的节能减排效益进行了计算,分析了合理弃风对全系统节能减排效益的影响。 相似文献
30.
《Journal of Great Lakes research》2002,28(2):212-227
Despite the documented importance of hydrodynamics in influencing the structure and function of Great Lakes coastal wetlands, systematic assessments of coastal wetland hydrology are lacking. This paper addresses this gap by describing patterns in lake and tributary inputs, water residence times, and mixing regimes for a suite of western Lake Superior wetlands that differ in the amount of tributary and seiche flow they receive. We show that variability in tributary flows among wetlands and over time is far greater than variability in seiche-driven water movements, and that the amount of tributary flow strongly influences wetland hydrology via effects on water mixing and residence times, seiche size, mouth closures, and relative amounts of main and off-channel areas. Wetland seiche amplitudes were reduced in systems with small mouth openings and wetland mouth size was correlated with tributary flow. All wetlands experienced seiche-driven water level oscillations, but there was lake water intrusion only into those wetlands where tributary outflow was small relative to the seiche-driven inflow. Wetlands in settings exposed to long-shore sediment transport exhibited periodic mouth closures when stream flows were low. The absolute and relative size of lake and tributary inputs must be explicitly considered in addition to wetland morphology and landscape setting in studies seeking to understand determinants of coastal wetland structure, function, and response to anthropogenic stressors. 相似文献