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1.
黄河兰州段水质周年理化参数监测分析   总被引:1,自引:0,他引:1  
张世敏  刘教练  徐淑霞  任丹  耿伟 《河南科学》2013,(12):2327-2330
通过对黄河兰州段进行周年理化检测分析,掌握其变化规律,以期为水质监控提供理论依据.研究表明。黄河兰州段水环境理化参数随着不同采样点与季节的变化而不同,水体温度随季节间变化剧烈,在1.8。18℃之间。夏季温度最高,冬季温度最低;水体呈弱碱性,pH值在8.3~8.6之间;关键水质监测参数分析发现水质类别为II~111类,其中II类水质占83%,Ⅲ类水质占17%,包兰桥断面的水质相对较差.  相似文献   

2.
三峡工程蓄水前后库区水质变化及对策分析   总被引:3,自引:0,他引:3  
据国家环保部长江三峡工程生态与环境监测公报(简称三峡公报)发布的1996-2008年三峡库区的水质监测实测数据进行分析整理.以2003年和2006年作为标志性节点,分析其水质变化趋势.结果表明:三峡库区沿程干流及远坝支流乌江除2006年及嘉陵江除2004、2006年外,其余年份水质均达到或优于Ⅲ类水质断面,受蓄水影响不...  相似文献   

3.
根据2002年和2006年长江三峡库区巴东段的七个监测断面的水质监测结果,采用综合污染指数法(P值法)对各监测断面、城区江段以及其总体水环境质量进行了综合评价。结果表明,巴东段2002年水质状况属于中度污染,2006年水质状况属于轻度污染,主要污染区域为长江干流巴东段和神农溪;主要污染物是粪大肠菌群、氨氮、总氮、总磷和石油类。  相似文献   

4.
为探究调水过程中望虞河水体水质风险状况,对2008年引江济太期间望虞河水质风险进行了识别,并采用三角模糊数的α-截集技术对望虞河各监测断面风险因子进行风险率计算,以分析望虞河各断面水体水质风险率及其风险等级。结果表明,造成望虞河水体水质恶化的风险因素主要为望虞河西岸支流污水汇入及污染物二次迁移;江边闸内断面各风险因子风险率较大,风险等级也较高;虞义大桥断面水体具有较低风险和较高风险两个等级;张桥断面各风险因子的风险率较小,风险等级也较低;大桥角新桥断面水体中除高锰酸盐指数外,其余风险因子风险率都较大,风险等级为较高风险;望亭闸下断面各风险因子风险率为0,无水质恶化风险。  相似文献   

5.
三峡成库后重庆段运行水位流场模拟   总被引:1,自引:0,他引:1       下载免费PDF全文
基于圣维南方程组,采用隐式差分格式求解,建立了一维流场模型,计算了三峡库区重庆段,从寸滩断面到市域出口共500余km长江干流江段整体水流特征.对三峡成库后2个典型蓄水位条件下重庆段水流状态进行了模拟预测.预测结果表明:三峡水库蓄水后,坝前156m水位条件下,回水区水面宽度是建库前的3倍左右,断面平均流速仅为建库前的1/3左右;坝前175m水位条件下,回水区水面宽度是建库前的3.5倍左右,断面平均流速仅为建库前的1/4左右.模拟结果反映了建库前后长江干流一维流场的变化特点.它为分析三峡水库在不同水位运行时对重庆段水流状态及生态环境的影响范围及程度提供了参考.  相似文献   

6.
黄浦江水环境模拟计算边界条件影响分析   总被引:1,自引:1,他引:1  
在大系统多尺度耦合模型基础上,细化黄浦江干流二维模型,分析了边界条件对黄浦江干流水环境模拟计算的影响,认为:黄浦江干流水动力条件主要受上游米市渡边界潮汐流量和下游吴淞口边界潮汐水位的影响,各支流汇人流量(即侧边界)基本不产生影响.黄浦江干流水质主要受上游米市渡来水、沿岸排放污染源的共同影响,其中黄浦江上游松浦大桥断面水质主要受上游米市渡来水的影响;黄浦江干流中游临江、南市水厂断面水质受上游米市渡来水、沿岸排放污染源的共同影响;黄浦江下游杨浦大桥断面水质主要受沿岸排放污染源的影响.  相似文献   

7.
人控调度方案对库区支流水动力和水质的影响机制初探   总被引:2,自引:0,他引:2  
水库蓄水运行后将显著改变库区支流的水动力和水质条件.在这种既定状态,改变枢纽的人控调度方案将产生不同的调度期库区出口断面泄流过程和库水位变动过程,进而产生不同的库区支流水动力条件.水动力条件的改变将对支流水质产生不同影响.基于此,以三峡水库为例,结合实测地形资料构建了三峡库区一维水动力和水质模拟模型,并通过模拟详细探讨了三峡枢纽不同人控调度方案对库区支流水动力和水质的影响.香溪河支流模拟结果表明:三峡枢纽的调峰运行方案和三峡水库的蓄放方案可产生人工潮汐作用和整个支流范围内的干支流水体交换和掺混,提高支流水体流速,对改善支流水环境有利.  相似文献   

8.
西安市周边河流水质F-G综合评价研究   总被引:1,自引:0,他引:1  
在国家《地面水质标准》的基础上,依据黄金分割法确定了河流水质评价基准;将模糊评价和灰色聚类(F-G)两种方法结合起来,对西安城市周边10条河流26个断面进行了F-G综合评价.结果显示:渭河、浣河属于污染最严重的超Ⅴ类水质,黑河上游为优良Ⅰ类水质,泸河、灞河、沣河等均有从上游向下游污染加重的趋势,涝河、新河、临河入渭口均属Ⅵ水质;纠正了传统指数模型对一些区段的认识,为河流水质的综合防治提供了新依据.  相似文献   

9.
2006年12月底,将湛江港划分为码头和七个断面,每个断面分为三个监测点进行调查,应用灰色聚类法对其水质测量结果进行综合评价,结果表明:从空间分布上看,各监测点水质状况好坏差别较大,断面Ⅰ、Ⅱ、Ⅲ、Ⅶ为一类水质,断面Ⅳ、Ⅴ、Ⅵ、码头为三类水质,污染严重。  相似文献   

10.
徐州市区地表水环境质量评价与污染防治对策   总被引:6,自引:0,他引:6  
根据徐州市2003年水环境监测资料,运用模糊综合评判法,对该区的水环境质量污染现状进行了评价,分析了水污染的原因,并据此提出了污染防治对策.评价结果表明,云龙湖各监测断面水质基本能够达到Ⅱ~Ⅲ类水质,京杭运河为Ⅲ~Ⅳ类,废黄河除了三环西路监测断面为Ⅳ类外,其余各监测点以及京杭运河各支流和奎河各断面均为Ⅴ类水.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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