首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   90篇
  免费   4篇
  国内免费   8篇
环保管理   6篇
综合类   24篇
基础理论   36篇
污染及防治   10篇
评价与监测   22篇
社会与环境   4篇
  2023年   1篇
  2021年   2篇
  2020年   4篇
  2019年   1篇
  2018年   2篇
  2016年   2篇
  2015年   4篇
  2014年   8篇
  2013年   8篇
  2012年   3篇
  2011年   9篇
  2010年   10篇
  2009年   9篇
  2008年   4篇
  2007年   7篇
  2006年   5篇
  2004年   1篇
  2003年   2篇
  2002年   3篇
  2001年   2篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1996年   3篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
排序方式: 共有102条查询结果,搜索用时 46 毫秒
1.
于2018年—2019年在鄱阳湖区周边选取4个县(区)10个村庄的典型门塘开展浮游藻类采样调查。研究共鉴定出藻类6门83种,以蓝藻门、绿藻门和硅藻门为主;浮游藻类细胞密度全年范围为7.30×104个/L~2.78×1011个/L,年均值为1.4×1010个/L,其中夏季细胞密度最大,冬季细胞密度最小;优势种主要有小环藻、微囊藻、铜绿微囊藻、卵形隐藻等,且具有较为明显的季节演替,全年优势种为小环藻;藻类多样性指数(H′)年均值为1.49,丰富度指数(M)年均值为1.92,全年水体生物学评价结果为中度污染。  相似文献   
2.
We examined long-term data on water chemistry of Lake Rachelsee (Germany) following the changes in acidic depositions in central Europe since 1980s. Despite gradual chemical recovery of Rachelsee, its biological recovery was delayed. In 1999, lake recovery was abruptly reversed by a coincident forest die-back, which resulted in elevated terrestrial export of nitrate and ionic aluminum lasting ~5 years. This re-acidification episode provided unique opportunity to study plankton recovery in the rapidly recovering lake water after the abrupt decline in nitrate leaching from the catchment. There were sudden changes both in lake water chemistry and in plankton biomass structure, such as decreased bacterial filaments, increased phytoplankton biomass, and rotifer abundance. The shift from dominance of heterotrophic to autotrophic organisms suggested their substantial release from severe phosphorus stress. Such a rapid change in plankton structure in a lake recovering from acidity has, to the best of our knowledge, not been previously documented.  相似文献   
3.
Historical data indicate that the dominance of submerged plants in Dianchi Lake in the 1960 s was characterized by low algal density with dominance of non-toxic group J(Scenedesmus,Pediastrum,etc.). The removal of submerged plants,which began in the 1970 s,resulted in the expansion of bloom-forming Microcystis(group M). Laboratory experiments suggested that Microcystis aeruginosa was inclined to grow and develop at elevated temperatures. The growth of Scenedesmus obliquus was slower than that of co-cultivated M. aeruginosa in the absence of Ceratophyllum demersum,especially at higher temperatures. The existence of submerged plant C. demersum could inhibit the growth of the harmful algae M. aeruginosa and this inhibitory effect by C. demersum was enhanced with an increase in temperature. Instead,with C. demersum,the growth of S. obliquus was not inhibited,but the co-cultivated M. aeruginosa was eliminated in a short time. Combined with the historical data and laboratory experiments,it was indicated that the submerged plants might play important roles in the dominance of the non-toxic group J in the historical succession. Consequently,the introduction of the submerged plant such as C. demersum might alter the dominant phytoplankton functional groups from M to J and benefit the restoration of the eutrophic lake.  相似文献   
4.
对2013年夏季南岔湖的浮游植物进行了初步研究,共鉴定初浮游植物6门,8纲,13目,24科,43属,共94个分类单位。其中优势种6种。南岔湖水体属于中污染。  相似文献   
5.
本文通过2006~2010年五年间对水质生物学评价指标一浮游植物种类和数量的变化来评价红旗水库水质的现状,得出红旗水库水质属于轻污一中污染水体,但仍然符合饮用水源地标准。  相似文献   
6.
The growth and alkaline phosphatase activity (APA) of two raphidophyceae species Chattonella marina and Heterosigma akashiwo were investigated in response to P-limitation and subsequent addition of dissolved inorganic phosphorus (DIP, NaH2PO4) and two dissolved organic phosphorus (DOP) compounds: guanosine 5-monophosphate (GMP) and triethyl phosphate (TEP). APAlevels increased greatly after P-starvation as the decrease of the cellular phosphorus quotes (Qp). C. marina responded to P-limitation quickly and strongly, with 10-fold increase in APA within 24 hr after P-starvation. The larger difference between maximal and minimal Qp values in C. marina indicated its high capacity in P storage. APA of H. akashiwo wasmaximally enlarged about 2.5 times at 48 hr of P-starvation. After the addition of nutrients, cell numbers of C. marina increased in all treatments including the P-free culture, demonstrating the higher endurance of C. marina to P-limitation. However, those of H. akashiwo increased only in DIP and GMP cultures. APA increased only after the addition of the monophosphate ester GMP. The results suggest that quick responses of C. marina to P-limitation, high capacity in P storage as well as endurance for P-depletion provide this species an ecological advantage in phytoplankton community competition under DIP-limited conditions.  相似文献   
7.
淀山湖浮游植物营养限制因子的研究   总被引:5,自引:0,他引:5  
通过藻类增长的生物学评价(Nutrient Enrichment Bioassay)研究淀山湖浮游植物生长限制性因子,并采用析因方差分析和事后比较方法分析营养盐(PO3-4P、NH3N、NO-3N)对浮游植物生长速度、平均最大现存量和平均最大特定增长率的影响。研究表明:磷对浮游植物生长有明显的促进作用,能提高浮游植物的生长速度和现存量,且促进作用随磷浓度(0.13~0.53 mg/L)的增加而加强,磷是淀山湖浮游植物增长的第一限制性因子;低浓度硝氮(2.91~5.91 mg/L)对浮游植物生长有微小的促进作用,但高浓度(5.91~8.91 mg/L)的硝氮表现出抑制作用;氨氮对浮游植物生长有抑制作用,并随浓度(1.25~7.25 mg/L)的增加而增大;添加磷+硝氮能明显促进浮游植物生长,磷与硝氮之间存在一定的交互作用.  相似文献   
8.
Havenhand JN 《Ambio》2012,41(6):637-644
Increasing partial pressure of atmospheric CO2 is causing ocean pH to fall—a process known as ‘ocean acidification’. Scenario modeling suggests that ocean acidification in the Baltic Sea may cause a ≤3 times increase in acidity (reduction of 0.2–0.4 pH units) by the year 2100. The responses of most Baltic Sea organisms to ocean acidification are poorly understood. Available data suggest that most species and ecologically important groups in the Baltic Sea food web (phytoplankton, zooplankton, macrozoobenthos, cod and sprat) will be robust to the expected changes in pH. These conclusions come from (mostly) single-species and single-factor studies. Determining the emergent effects of ocean acidification on the ecosystem from such studies is problematic, yet very few studies have used multiple stressors and/or multiple trophic levels. There is an urgent need for more data from Baltic Sea populations, particularly from environmentally diverse regions and from controlled mesocosm experiments. In the absence of such information it is difficult to envision the likely effects of future ocean acidification on Baltic Sea species and ecosystems.  相似文献   
9.
2012年夏季对金海水库水体物理和化学指标和浮游植物的群落结构组成进行了调查。结果表明,水库整体水质状态较为良好,金海水库夏季综合营养状态指数为42.34,水库水体在一定程度上已经呈现中营养水平向轻度富营养化转化的趋势。通过夏季对金海水库浮游植物的调查,共检出浮游植物27种,其中绿藻门14种,硅藻门7种,甲藻门2种,蓝藻门2种,裸藻门2种。优势种属为绿藻门和硅藻门,其中绿藻门的种类和数量均居于首位。  相似文献   
10.
阳澄湖浮游藻类现状调查及水质评价   总被引:1,自引:0,他引:1  
对苏州阳澄湖2009年-2011年的浮游藻类现状进行调查,采用硅藻指数和Shannon-wiener指数两种生物学指数评价阳澄湖水体污染状况.结果表明,在阳澄湖发现浮游藻类219种(包括变种),秋季的浮游藻类种类数多于春季;阳澄湖水质尚好,东湖南富营养化程度较为严重.目前阳澄湖的有机污染处于缓慢上升的态势,富营养化水平也不断提高.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号