9 research outputs found

    Preliminary Analysis of Spatiotemporal Variation of Water Quality and Its Influencing Factors in the Jiulong River Watershed

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    选取闽东南九龙江流域21个典型小流域开展2010年丰(8月)、平(11月)、枯(2月)3个水期的基流水质监测,并借助gIS、多元统计分析方法识别流域水质的时空分布特征及其影响因素,为九龙江流域水质监测、管理与控制提供依据.结果表明,九龙江水质枯水期最差,平水期次之,丰水期水质较好.表征生活污水、工业废水的污染因子对水质变化的贡献率为45.58%,表征农业污染的主成分的贡献率为21.28%.nH4+-n、SrP、高锰酸盐指数、k+、Cl-、Mg2+、nA+浓度与建设用地比例、人口密度呈显著的正相关,nO3--n浓度与耕地比例有显著的正相关,自然用地面积比例与nO3--n、k+、Cl-、nA+浓度有显著的负相关.建设用地比例较大、人口较密集的小流域nH4+-n、SrP、高锰酸盐指数、k+、Cl-的浓度较高,耕地比例较大的小流域nO3--n浓度则较高.在流域水质管理上,建议提高污水处理率,并重视由于化肥施用导致的农业非点源污染对水质的影响.Twenty one sub-watersheds in the Jiulong River watershed were chosen for in-situ monitoring water quality of baseflow in flood season,dry season and average season in 2010.Geographical information system and multivariate analysis were coupled to characterize the spatiotemporal variation of water quality and identify its influencing factors.The results show that the water quality in dry season is the worst whereas the water quality in flood season is comparatively good.The first principal component representing sanitary and industrial wastewater pollution,explained 45.58% of the total variance of water quality.The second principal component concerning pollution due to agricultural activities,explained 21.28% of the total variance.NH+4-N,SRP,potassium permanganate index,K+,Cl-,Mg2+ and Na+had a significantly positive correlation with percentage of built-up and density of population.NO-3-N was correlated positively with percentage of cropland.The sub-watersheds with high proportion of build-up area and density of population show high concentration of NH+4-N,SRP,potassium permanganate index,K+,Cl-.Comparatively,the sub-watersheds with high percentage of cropland show high level of nitrate concentration.Improvement of the wastewater treatment efficiency and increased recognition of agricultural non-point source pollution were finally highlighted from watershed management perspectives.国家自然科学基金项目(40901100;40810069004);福建省自然科学基金项目(2009J01222

    Analysis of Spatiotemporal Variability of Runoff Flashiness Index for Jiulongjiang River

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    通过分析河流flASHInESS指数的时空变异,进而评估水电开发、土地利用变化等人类活动对河流径流时空变异特征的影响。本研究选取地处东南沿海的中尺度流域——九龙江流域,基于1967~2007年近40年的水文资料,利用flASHInESS指数、基流指数等重要水文指数,并借助gIS、多元统计分析的方法来识别九龙江北溪与西溪两大干流流域近40年来径流时空变化特征及其影响因素。研究结果表明,九龙江流域近40年来径流特征发生显著的变化,流域面积是影响九龙西溪和北溪径流时空变化的自然因素,大坝建设、水电开发改变了九龙江流域的水文条件,进而影响了径流量的年内分布规律及泥沙输出特征,土地利用变化是影响流域径流特征变化的潜在因子。研究结果可为流域水资源管理提供科学依据。Spatiotemporal variability of the runoff flashiness index was explored and thereby used to evaluate the effect of human activities including dam construction and land use change on runoff variation.The Jiulongjiang River Basin, the medium-sized coastal watershed located in SE China, was chosen to analyze the characteristics of the runoff variation with Flashiness Index(FI)and Baseflow Index(BFI) for the north reach and west river of the Jiulongjiang River, based on the forty-year hydrologic data from1967 to 2007.The geographical information system and multivariate analysis were coupled to characterize the spatiotemporal varia-tion of the runoff and identify its influencing factor.The results show that the hydrological condition in the Jiu longjiang River Basin was altered significantly in the past 40 year, represented by a decreasing tend for FI and an increasing trend for BFI.Furthermore, the watershed area is the major natural factor leading to spatiotemporal variability of the runoff flashiness index for the north reach and west reach of the Jiulongjiang River.The Dam construction and hydropower development made the hydrological condition changed in the Jiulongjiang River Basin, which greatly influenced the seasonal variability of the runoff and sediment dis-charge.The land use change was identified as a potential factor influencing the runoff variation of the Jiulong River Basin.国家自然科学基金项目(40901100;40810069004); 福建省水利厅项目(FJSW2013038

    薄壁真空管道及由薄壁真空管道制造真空室的制造方法

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    <span style="color: rgb(69, 69, 69); font-family: Arial, Helvetica, sans-serif; line-height: 21px; text-indent: 24px;">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;本发明主要涉及电真空设备的制造方法,尤其涉及一种可以在高频交流电场或交变磁场下使用的真空管道的制造方法。一种薄壁真空管道的制造方法,包括制管、卷边、设置加强筋等多个步骤,还提供一种由制成的真空管道制造真空室的制造方法,包括焊管、制造液压波纹管装置等工艺,用此工艺程序、参数和方法匹配制造出的薄壁真空管道,整个真空管道尺寸大、通体薄壁,能够满足在高频交流电场或交变磁场下使用要求。</span

    低浓度乙烯气或催化裂化干气制取乙苯

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    研制了低浓度乙烯或催化裂化干气制乙苯用的高硅沸石催化剂。所用催化干气未气末经分离和纯化, 研究了杂质气体H2S, CO2和H2O对乙基化的影响。考察了反应条件的影响, 并得到最佳操作参数。乙烯转化率可大于90%, 催化剂的单程操作时间大于50天, 失活催化剂经烧炭再生可恢复始活性和选择性

    H型冲片二极弯曲电磁铁

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    本实用新型主要涉及带电粒子传输使用的电磁铁,主要涉及带电粒子偏转用装置。一种H型冲片二极弯曲电磁铁,其山字形铁芯冲片(2)叠压成山字形磁铁组(1),山字形磁铁组由上磁铁组(1-1)和下磁铁组(1-2)组成,上磁铁组(1-1)和下磁铁组(1-2)为弧形,上磁铁组(1-1)和下磁铁组(1-2)相对设置形成H形空隙,上励磁绕组(4)和下励磁绕组(5)之间设有上、下调整块(6);在磁铁组(1)上设有上调差线圈固定架(7)和下调差线圈固定架(8),其上固连有电联接上、下铜排(9);上、下调整块(6)之间设有高度为75-85mm的通道,在磁铁组(1)内弧侧面设有集流管(10)。其磁场质量高,磁铁重复性好,工作效率高

    C型冲片二极弯曲电磁铁

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    本实用新型主要涉及带电粒子传输使用的电磁铁,主要涉及带电粒子偏转用装置。一种C型冲片二极弯曲电磁铁,其C字形铁芯冲片(2)叠压成C型磁铁组(1),C型磁铁组(1)为弧形,C型磁铁组(1)的C字形开口处形成丁字形空隙,上励磁绕组(3) 和下励磁绕组(4)分别缠绕在C型磁铁组(1)的上下C字形开口处,在C字形开口内设有调高块(5);在C型磁铁组(1)左端部分别设有第一线圈固定块(7)、第二线圈固定块(8)、第三线圈固定块(9),C型磁铁组(1)的C字形开口处设有高度为80-90mm 的通道,在磁铁组(1)内弧侧面设有集流管(10)。其采用改进性C型冲片,磁场质量高,磁铁重复性好,工作效率高

    半胶粘二分冲片四极电磁铁

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    本实用新型主要涉及带电粒子传输使用的电磁铁,主要涉及一种用于带电粒子束流聚焦的一种半胶粘二分冲片四极电磁铁,其铁芯冲片(2)通过胶合构成粘结端板(3),两端各一件粘结端板(3)中间夹散铁芯冲片(2)构成磁铁铁芯(1),铁芯(1)由上铁芯(1-1)和下铁芯(1-2)组成,上磁铁组(7-1)和下磁铁组(7-2)相对设置形成四极电磁铁,上磁铁组(7-1)上设有第一极线圈(8-1)和第二极线圈(8-2),下磁铁组(7-2)上设有第三极线圈(8-3)和第四极线圈(8-4),各极线圈的引线分别用线圈压块(9)固定在上磁铁组(7-1)和下磁铁组(7-2)的侧面,下磁铁组(7-2)安装在底座(10)上。其磁场质量高,磁铁稳定性好,工作效率高

    乙烯与甲苯乙基化制对甲基乙苯反应用沸石催化剂

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    一种用于甲苯与乙烯进行烷基化反应,特别是适宜用于低浓度乙烯为原料的甲苯烷基化反应过程所用含有锑(或磷)及镁元素化学改质处理的Pentasil型硅铝沸石催化剂。这种沸石催化剂可以直接用含有硫化氢、水等杂质的炼油厂尾气(含乙烯10-20%)作原料与甲苯反应制取主要为对位甲基乙苯的过程。与以纯乙烯为原料的甲苯烷基化反应进程相比,当直接采用含杂质的低浓度乙烯的炼油厂尾气为原料时,本发明的沸石催化剂具有良好的反应性能。带填
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