应用灰色聚类法进行地下水水质分类的尝试     

王佳武 《陕西地质》1992,(1)

本文应用灰色系统理论中的灰色聚类法,试对渭南市白杨水源地地下水水质进行综合分类,结论表明该方法是可行的。  相似文献   

Removal of bisphenol A (BPA) from biologically treated wastewater by microfiltration and nanofiltration     

M. Zielińska  K. Bułkowska  A. Cydzik-Kwiatkowska  K. Bernat  I. Wojnowska-Baryła 《International Journal of Environmental Science and Technology》2016,13(9):2239-2248

Bisphenol A (BPA) is an endocrine disruptor that is difficult to completely remove from wastewater by conventional biological methods. Increased post-treatment BPA removal with ceramic membranes is worth investigating because of these membranes’ mechanical and chemical stability and lifespan. To determine the effectiveness of ceramic membranes for post-treatment of biologically treated BPA-contaminated wastewater, microfiltration (MF) and nanofiltration (NF) were conducted. Both processes removed BPA completely at an initial BPA concentration of 0.3 ± 0.14 mg/L. Increased concentration of 0.7 ± 0.29 mg/L decreased BPA removal. MF removed at least 24 % of BPA, presumably because BPA was adsorbed on particulate matter, which was retained by the membrane, or adsorbed on its surface. NF removed up to thrice more BPA. MF and NF completely removed suspended solids and 40–60 % COD. Filtration capacity decreased with time due to fouling but did not depend on initial BPA concentration. BPA concentrations in municipal wastewater are typically lower than the lowest concentration tested, where MF completely removed BPA. Hence, MF ceramic membranes appear a promising solution for post-treatment of BPA-containing wastewater. MF can be used at a much lower transmembrane pressure than NF, requiring less energy to pump wastewater through the membrane, thus reducing costs.  相似文献   

长治市2003年8月26日暴雨过程分析          下载免费PDF全文

王正旺  白根俊  庞转棠  魏建军  卜祥朔 《山西气象》2004,(3):3-4,34

本文运用天气形势，物理量场，单站总温度对2003年8月26日长治市区域性大暴雨进行了综合分析，找出了此次暴雨天气产生的环流背景，影响系统，物理量场在暴雨中的特征以及单站总温度在暴雨中的变化规律。  相似文献   

长治市气象台报务转发系统          下载免费PDF全文

杨建民  王宗仁  卜祥朔  孙英杰 《山西气象》2004,(3):25-26

在地市气象台向省气象台转发气象报文时，由于县局与市局报路时有不畅，且常有停电现象，使得传统的方法很烦琐，不符合时代发展的要求。为此．我们开发了《长治市气象台报务转发系统》。目前该系统已开发完成，本文主要介绍该系统的开发和主要功能。  相似文献   

Bericht über die Arbeiten ichthyologischer und fischereilicher Art,die für die 13. Arbeitssitzung der Internationalen Arbeitsgemeinschaft Donauforschung vorgelegt wurden     

Prof. Dr. Th. Buşniţa 《Aquatic Sciences - Research Across Boundaries》1971,33(1):322-333

Ohne Zusammenfassung  相似文献   

杭州市滑坡地质灾害危险性区划与评价     

俞布  潘文卓  宋健  缪启龙  张玮玮  段春锋 《岩土力学》2012,33(Z1):193-199

基于证据权法构建滑坡地质灾害评价模型,进行杭州市滑坡地质灾害危险性区划研究。主要数据源包括1930－2009年杭州市域采集到的1 905个地质灾害个例以及杭州市地质图、土地利用数据及数字高程模型（DEM）等。利用Arcgis空间分析及信息提取功能,筛选强降水、地层岩性、坡度、坡向、坡高、河网与道路缓冲等证据因子,并运用证据权法客观确定各因子权重, 最后通过Arc-WofE扩展模块对多种优选因子的叠加,计算任意格网单元的滑坡发生概率,实现对潜在滑坡点位的空间预测。经分离样本法验证,区划准确率为88.3%,分析结果与现有滑坡的分布情况比较吻合。据此表明证据权法在多指标评价及其权重确定等方面具有普适性,值得在滑坡地质灾害危险性区划等方面推广应用。  相似文献   

我国季风边缘区湖泊沉积记录的全新世亚洲夏季风衰退事件     

吴铎  周爱锋  张家武  陈建徽  程波  陈婕  魏海涛 《第四纪研究》2019,39(3):665-677

亚洲夏季风是全球季风系统的重要组成部分,亚洲夏季风的变化对其控制区域自然生态系统的多样性和生态平衡,以及社会经济发展有重要的影响。本文选择位于现代亚洲夏季风边缘区对季风变化响应敏感的湖泊达连海为研究对象,基于陆生植物残体和全有机质的AMS14C定年建立了钻孔顶部24.6 m沉积物的年代框架,利用粒度指标重建了全新世研究区水文变化过程以及亚洲夏季风衰退事件序列。结果显示,沉积物中存在数层砂层,代表了湖泊低水位时期,进而指示了亚洲夏季风衰退事件。这些事件处在11.6~11.3 cal.ka B.P.、10.4~9.5 cal.ka B.P.、6.4~6.0 cal.ka B.P.、4.6~4.4 cal.ka B.P.、3.7~3.4 cal.ka B.P.、3.1~2.9 cal.ka B.P.以及2.0~0.9 cal.ka B.P.,可以发现中晚全新世以来亚洲夏季风衰退事件发生的频率显著增加。进一步与北半球高纬地区与低纬地区的气候突变事件记录对比显示,全新世百年-千年时间尺度上亚洲夏季风强度的变化与低纬ENSO活动存在密切的联系。  相似文献   

安徽蒙城西贾庄铁金多金属矿金的赋存状态     

卜香萍  黄博  徐旭峰 《江苏地质》2019,43(1):81-85

安徽蒙城西贾庄铁金多金属矿床是蚌埠隆起地区新发现的一个重要矿床。在矿相学观察和研究的基础上,开展了矿石的电子探针分析(EPMA),以查明矿石中金的赋存状态。研究结果表明,金矿赋存状态既有可见的显微自然金,也有的以不可见金的形态赋存于黄铁矿、毒砂和黄铜矿中。研究成果为矿床成因、成矿物质来源等研究提供了重要依据  相似文献   

基于MODIS数据的青藏高原旱情监测研究   总被引：5，自引：0，他引：5  

杨秀海  卓嘎  罗布 《中国沙漠》2014,34(2):527-534

本文利用温度植被旱情指数（TVDI）和植被供水指数（VSWI）分别对2009、2010年3—10月青藏高原土壤湿度状况进行监测分析,同时利用气象台站实测地面降水资料进行了验证。利用MODIS资料提取的归一化植被指数（NDVI）和地表温度（T_S）,构建NDVI-T_S特征空间,依据该特征空间计算出的反映青藏高原土壤湿度的TVDI与同期累积降水相关性显著;VSWI计算过程简单,但所反映的土壤湿度与同期累积降水的相关性较差。因此,对青藏高原这种范围广、下垫面多变复杂区域而言,TVDI能够更好地反映土壤湿度状况,对干旱监测具有一定的科学意义。  相似文献   

A review of historical reconstruction methods of land use/land cover   总被引：2，自引：1，他引：1  

Yuanyuan Yang  Shuwen Zhang  Jiuchun Yang  Liping Chang  Kun Bu  Xiaoshi Xing 《地理学报(英文版)》2014,24(4):746-766

Understanding long-term human-environment interactions requires historical reconstruction of past land-use and land-cover changes. Most reconstructions have been based primarily on consistently available and relatively standardized information from historical sources. Based on available data sources and a retrospective research, in this paper we review the approaches and methods of the digital reconstruction and analyze their advantages and possible constraints in the following aspects: (1) Historical documents contain qualitative or semi-quantitative information about past land use, which also usually include land-cover data, but preparation of archival documents is very time-consuming. (2) Historical maps and pictures offer visual and spatial quantitative land-cover information. (3) Natural archive has significant advantages as a method for reconstructing past vegetation and has its unique possibilities especially when historical records are missing or lacking, but it has great limits of rebuilding certain land-cover types. (4) Historical reconstruction models have been gradually developed from empirical models to mechanistic ones. The method does not only reconstruct the quantity of land use/cover in historical periods, but it also reproduces the spatial distribution. Yet there are still few historical land-cover datasets with high spatial resolution. (5) Reconstruction method based on multiple-source data and multidisciplinary research could build historical land-cover from multiple perspectives, complement the missing data, verify reconstruction results and thus improve reconstruction accuracy. However, there are challenges that make the method still in the exploratory stage. This method can be a long-term development goal for the historical land-cover reconstruction. Researchers should focus on rebuilding historical land-cover dataset with high spatial resolution by developing new models so that the study results could be effectively applied in simulations of climatic and ecological effects.  相似文献