基于主成分分析法的石家庄市民心河水质评价研究

由于影响水环境质量的因素较多,而水质系统是由多维因子组成的复杂系统,每一因子从某一方面反映了水体质量状况,各因子对环境污染又有着不同的贡献率,并且因子间具有不同程度的相关性,依据它们作综合评价有一定难度.所以,做好水环境质量评价工作,选取一种有效而又实用的方法是非常重要的.利用水质综合评价的主成分分析方法,借助spss软件对石家庄市民心河2010年18个典型断面的水质污染程度进行定量化评价,实证分析的结果表明,新石南路断面水质最差,联盟西路与西二环交叉口监测断面水质污染最轻.     

东圳水库生态环境与水资源保护的探讨

该文介绍了东圳水库库区的生态环境和水质现状,对引起库区水土流失和水资源污染的原因进行了分析,并提出了保护水库生态环境和水资源的建议.     

龙开河水环境质量的探讨

根据龙开河的具体流向情况，依据节点原则，在龙开河上设置三个监测断面，根据对这三个监测断面的水质监测结果分析，确定龙开河的主要水质污染物为氨氮、生化需氧量、高锰酸盐指数和挥发性酚，水体污染为有机污染物，根据这一水质污染特征，对龙开河的水质污染状况及形成原因进行具体分析，并提出合理化建议。     

长江三峡库区水污染及成因

长江三峡工程的兴建,实现了长江水资源优化配置及可持续利用。三峡工程自1994年动工,至2 0 0 2年11月成功实现了三期截流,2 0 0 3年6月水库开始蓄水以来,在6 0 0多千米长的三峡水库形成后,保护水库水质问题将是一项长期而艰巨的任务。三峡工程的建设对形成的库区水质的不利影响主要表现在水位抬高,水流趋缓,不利于污染物的扩散,使现在排污染条件下的岸边污染范围扩大。水库初期正常蓄水位135米,对水质的不利影响范围主要集中在坝前至重庆长寿县城附近,水库按正常蓄水位175米蓄水后,对水质的不利影响范围将涉及整个库区。为此,三峡工程考虑了…     

丹江口水库及入库支流水质评价

采用一种全新的水质指数对丹江口水库及入库支流19个监测站点的水质监测数据进行分析和评价,得出入库支流中主要污染河流为神定河、泗河、犟河、剑河、浪河、老鹳河,主要污染指标为粪大肠菌群、氨氮、总磷、溶解氧等.库区与其他入库支流水质状况良好,除粪大肠菌群之外,其他指标监测值基本满足Ⅰ类水标准限值要求.在SPSS软件中运用主成分分析法对主要污染指标进行相关性分析,得出主要污染指标两两相关性较好,很可能来自同一污染源.     

凯里市清水江流域水质污染状况及趋势分析

根据凯里市环境监测站长期监测资料,采用水质综合指数法,对凯里市清水江流域水质污染状况进行了综合分析和评价证据表明,凯里市清水江流域水质污染呈上升趋势。     

长江水质评判及预测的数学模型

长江水质的污染程度日趋严重,为了保护长江水资源,必须对长江水质进行评价和预测,进而采取措施来治理水质的污染.本文运用模糊数学理论建立了"长江流域水质综合评判"模型,对长江水质进行了全面的定量的综合评判.应用灰色系统理论,建立了灰色预测模型,从而科学地预测出长江未来水质污染的发展趋势.     

陕西关中段渭河水质评价及污染控制对策

利用1996～2000年渭河流域陕西段11个监测断面的5年平均监测资料,采用分级评价法对渭河水污染进行了综合评价,分析了近年来渭河水体污染程度严重加剧的原因。最后,提出了渭河污染防治的对策。     

游客旅游活动对广安市响水滩水库水质影响的时间序列分析

近些年广安市响水滩水库旅游开发力度不断加强,给水库水体水质带来的影响越来越明显.为了评估游客旅游活动对其水体水质变化的影响,本研究通过选取分析响水滩水库3个不同功能区5个水质指标监测数据,并比较分析短期一周内水质监测数据、长期水质数据与游客量关系,以及2001—2012年的游客数量与水质综合污染指数关系.结果表明:1)周末的水质数据明显高于周中,二者的差异明显.水温与pH值的差异较小,而溶解氧(DO)、电导率(EC)和浑浊度(TUR)之间有明显的差异; 2)随着周末游客的增多,周末水库污水排放量超过一周内其他时间的总量,EC值升高; 3)水库的DO、EC和TUR与游客数量没有明显关联; 4)水质综合污染指数与旅游人数呈现相同波动变化趋势.结论:游客短期时间内的旅游活动对水库水质产生影响,而长时间内的旅游活动对水库水质的影响并不显著.研究结果旨在为该库区生态环境保护提供科学依据.     

桓仁水库水质状况的模糊综合评价及分析

通过采用模糊综合评价方法对桓仁水库四个不同断面及整个库区水质状况的综合评价,得出该水体水质符合国家Ⅰ级地面水的结论。分析了桓仁水库水质断面水质变化情况和水体自净能力,探讨了模糊综合评价的原理、方法及其在水体水质评价应用中的优点。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.