共查询到20条相似文献，搜索用时 203 毫秒
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何福林 《湖南科技学院学报》2003,24(5):70-71
从银鱼的分布、分类、形态特征、繁殖、生长规律、食性、种群及其特点等七个方面阐述了银鱼的生物学特性.依其生活习性,银鱼适宜于永州地区大小水库生长繁殖,大力发展银鱼水库养殖,对库区群众的脱贫致富和城乡居民的菜篮子工程可起到积极作用. 相似文献
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徐敏 《江苏经贸职业技术学院学报》2007,(1)
本文在实地调查几个典型水乡古镇的基础上,总结了古镇水域景观的共性特征,并从水域景观分布格局、水域景观特色、古镇区与新镇区比较、整治区与未整治区比较、镇区与镇区以外水域等五个方面阐述了江南水乡古镇水域景观的个性特征以及存在的一些问题。 相似文献
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污泥填埋对邻近水域水质的影响研究 总被引：1，自引：0，他引：1
为研究城市污水处理厂排放污泥可能对填埋区域邻近水域水质造成的影响,设计建成一个污泥填埋试验场,将污水处理厂的污泥堆埋在试验场,以填埋污泥作为污染源,结合邻近水域的地理分布,制定合理的水质监测方案,对污泥堆埋场邻近水域水质进行监测并采用单因子指标和综合指标两种方法进行水质评价。结果表明:填埋区域邻近水域的水质污染主要是富营养化和有机污染,主要超标项目为COD、高锰酸盐指数、T-P、NH3-N、T-N、粪大肠菌群群。污泥填埋场渗滤液主要为有机物和营养物质超标,主要超标项目为COD和NH3-N,重金属含量不高。由此可见,城市污水处理厂排放污泥的填埋对邻近水域水质产生了较为严重的二次污染。 相似文献
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采用原子吸收分光光度法对淮南谢二矿塌陷区老鳖塘与刘岗塘水体中Fe、Pb和Zn等重金属的含量进行了检测。结果表明：老鳖塘与刘岗塘水体中的Fe含量分别超出了集中式生活饮用水地表水源地补充项目标准限值的3倍和5．9倍;两塘水体中的pb含量分别属于地表水环境质量国家标准的Ⅳ类和Ⅴ类水质范畴;Zn的含量均属于地表水环境质量国家标准的Ⅴ类水质范畴。综上可见淮南煤矿塌陷区水体的重金属污染状况较严重。 相似文献
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采用实时荧光定量PCR和高效液相色谱技术对太湖南泉水域2009年5月至12月产毒微囊藻的环境丰度及其微囊藻毒素-LR产毒能力进行研究,并监测水质和富营养化程度.研究结果表明：南泉水域的水污染程度与富营养化程度均为中度;5月至11月蓝藻密度均超过水华的阈值;5月至10月产毒微囊藻的环境丰度均高于40%,随着温度的降低,产毒微囊藻的环境丰度迅速降低并在12月降到了5.66%;5月至12月产毒微囊藻的微囊藻毒素-LR产毒能力为1.661～9.293μg/亿细胞.11月至12月随着水温和藻密度的急速下降,产毒微囊藻的微囊藻毒素-LR产毒能力显著增强.结果提示太湖南泉水域全年大部分时间存在水华,产毒微囊藻为其优势藻,产毒微囊藻的环境丰度及其微囊藻毒素-LR产毒能力的动态变化和水温密切相关.冬季产毒微囊藻产毒能力的显著增强也提示在水华和非水华期内对其防制都应予以重视. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(5):10-11
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? 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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《海外英语》2007,(4):36
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. 相似文献
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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. 相似文献
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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献