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71.
热振森林大型土壤动物群落特征及其影响因素   总被引:1,自引:0,他引:1  
为了解西藏拉萨市林周县热振国家森林公园不同海拔大型土壤动物群落的空间分布特征及其与环境因子的关系,于2021年7月(夏季)根据其地理特征设置了三个不同海拔共9个样地.采用手捡法对大型土壤动物进行收集,并将其保存在75%酒精的收集管中,同时测定相应的环境因子.共捕获大型土壤动物1427个,经形态学鉴定隶属于2门5纲15目21科,其中优势类群为姬马陆科(Julidae)和蚁科(Formicidae),占总捕获量的66.0%.常见类群共10类,占总捕获量的31.3%;稀有类群占总捕获量的2.7%.热振国家森林公园大型土壤动物的类群、Shannon多样性指数、均匀度指数和优势度指数在三个不同海拔之间无显著性差异(P>0.05).大型土壤动物群落Jaccard相似性系数位于0.15~0.77.Pearson相关性结果显示,大型土壤动物个体数与海拔呈极显著负相关(P<0.01),与土壤温度和pH呈显著正相关(P<0.05);冗余分析显示,排序轴1和轴2共同解释了的类群组成变化的55.0%,全磷(TP)和有效磷(AP)为显著性解释变量,对大型土壤动物群落的解释率分别为29.6%和18.5%,是影响大型土壤动物群落的主要环境因子.  相似文献   
72.
崇明岛小白鹭鸟卵中有机磷阻燃剂污染特征   总被引:1,自引:0,他引:1  
鸟卵可用于环境质量的生物监测.从崇明岛东部若干林地采集小白鹭(Egretta garzetta)卵样品10个,用液相色谱-串联质谱联用仪(LC-MS/MS)测定了样品中10种常见有机磷阻燃剂(OPFRs)的含量,分析了其分布特征和来源.结果表明,除三辛基磷酸酯(TEHP)和三氯乙基磷酸酯(TCEP)外,其余8种OPFRs在小白鹭卵中均有检出,OPFRs的总含量为49.5~142.8 ng·g~(-1)(以湿重计,下同),均值为78.6 ng·g~(-1);其中,三丁基磷酸酯(TNBP)、三异丁基磷酸酯(TIBP)和三邻甲苯磷酸酯(TMPP)含量较为丰富,分别为(26.3±10.1)、(20.9±9.44)和(19.0±15.6) ng·g~(-1).不同鸟卵中OPFRs的赋存特征差异较大,主要受其环境含量水平、生物积累和放大能力及代谢能力的影响.崇明小白鹭卵样品中存在具有胚胎发育毒性的TMPP、三(1-氯-2-丙基)磷酸酯(TCIPP)、三丁氧基乙基磷酸酯(TBOEP)等,可能对其繁殖具有潜在影响,值得关注.  相似文献   
73.
袁林喜  祁士华 《环境化学》2011,30(12):1983-1992
传统意义上认为,持久性有机污染物(POPs)的传输途径主要有两种形式,一种是通过挥发之后进入大气,然后通过长距离大气传输、蚱蜢效应、高山冷凝效应等方式进行传输;另一种是进入水体中,通过水流的搬运作用传输,从而进入湖泊、河流生态系统,甚至可以通过洋流的长距离输送到达北极等高纬地区.另外,海鸟、候鸟和留鸟可以对POPs进行...  相似文献   
74.
Tamarix leaf beetles (Diorhabda carinulata) have been widely released on western United States rivers to control introduced shrubs in the genus Tamarix, with the goals of saving water through removal of an assumed high water‐use plant, and of improving habitat value by removing a competitor of native riparian trees. We review recent studies addressing three questions: (1) to what extent are Tamarix weakened or killed by recurrent cycles of defoliation; (2) can significant water salvage be expected from defoliation; and (3) what are the effects of defoliation on riparian ecology, particularly on avian habit? Defoliation has been patchy at many sites, and shrubs at some sites recover each year even after multiple years of defoliation. Tamarix evapotranspiration (ET) is much lower than originally assumed in estimates of potential water savings, and are the same or lower than possible replacement plants. There is concern that the endangered southwestern willow flycatcher (Empidonax trailli extimus) will be negatively affected by defoliation because the birds build nests early in the season when Tamarix is still green, but are still on their nests during the period of summer defoliation. Affected river systems will require continued monitoring and development of adaptive management practices to maintain or enhance riparian habitat values. Multiplatform remote sensing methods are playing an essential role in monitoring defoliation and rates of ET on affected river systems.  相似文献   
75.
Changes in the Caspian Sea level and anthropogenic influences on biocenoses of the Volga Delta periodically result in the changes of dominant species among animal helminths. An abrupt rise of the sea level since the mid-1970s caused structural rearrangements in the fluke fauna of fish in the 1990s: the species whose development is connected with mollusks of the rheophilic complex became dominant.  相似文献   
76.
An important rationale for legally farmed and synthetic wildlife products is that they reduce illegal, wild-sourced trade by supplying markets with sustainable alternatives. For this to work, more established illegal-product consumers must switch to legal alternatives than new legal-product consumers switch to illegal wild products. Despite the widespread debate on the magnitude and direction of switching, studies among actual consumers are lacking. We used an anonymous online survey of 1421 traditional Chinese medicine consumers in China to investigate switching among legal farmed, synthetic, and illegal wild bear bile. We examined the past consumption behavior, applied a discrete choice experiment framed within worsening hypothetical disease scenarios, and used latent class models to investigate groups with shared preferences. Bear bile consumers (86% respondents) were wealthier, more likely to have family who consumed bile, and less knowledgeable about bile treatments than nonconsumers. Consumer preferences were heterogenous, but most consumer preferences switched between bile types as disease worsened. We identified five distinct latent classes within our sample: law-abiding consumers (34% respondents), who prefer legal products and were unlikely to switch; two all-natural consumer groups (53%), who dislike synthetics but may switch between farmed and wild; and two nonconsumer groups (12%), who prefer not to buy bile. People with past experience of bile consumption had different preferences than those without. Willingness to switch to wild products was related to believing they were legal, although the likelihood of switching was mediated by preferences for cheaper products sold in legal, familiar places. We found that consumers of wild bile may switch to legal alternatives, given the availability of a range of products, whereas legal-product consumers may switch to illegal products if the barriers to doing so are small. Understanding preferences that promote or impede switching should be a key consideration when attempting to predict consumer behavior in complex wildlife markets.  相似文献   
77.
对越冬迁徙期间中途停留在天津北大港的野生鸟类-东方白鹳(Ciconia boyciana)体内肌肉、肝脏、心脏、胃和脾中∑OCPs浓度进行了检测.各组织中检出的∑OCPs平均浓度(浓度范围,以脂重计)在心脏中最高,为955.30ng/g(88.65~4102.577ng/g),次之为肝脏,平均浓度为465.55ng/g(37.96~1476.17ng/g),再次之为胃、脾和肌肉,浓度分别为251.64ng/g(102.88~354.61ng/g)、176.5ng/g(158.72~194.50ng/g)和143.96ng/g(10.90~800.51ng/g).在肝脏和心脏中∑DDTs和浓度高于∑HCHs,在其它组织中则相反.与其它研究相比,本研究所检测鸟体内有机氯浓度较低,表明这批东方白鹳并尚未受到环境中OCPs的严重污染.  相似文献   
78.
我国鸟类监测的现状、问题与对策   总被引:2,自引:0,他引:2  
鸟类是开展生物多样性监测的重要指示类群.对鸟类的长期、系统监测工作在欧美已经有百余年历史,且野鸟多样性指数已经成为欧美一些国家开展生物多样性监测工作的官方指标.通过对国内鸟类监测现状的分析,结合监测对象、指标、抽样策略和监测方法等监测工作中应重点关注的几个方面,提出了我国鸟类监测存在的问题,并结合国情提出了下一步开展鸟类监测工作的对策与建议.建议我国有关部门尽快制定鸟类监测技术规程和标准,统一数据收集和分析平台,逐步构建政府引导,科研院所、高等院校、自然保护区、观鸟协会和志愿者等多方参与的鸟类监测网络.  相似文献   
79.
2010年12月、2011年1月、2月、3月、5月和8月,利用样带法对珠海市鹤洲湿地鸟类物种多样性进行研究,利用Shannon-Wiener指数分析了生境类型的鸟类群落种数、数量、物种多样性、均匀性指数等特征。结果表明,共记录到96种,隶属12目31科66属。鸟类多样性指数(H')进行了计算,12月3.6956,1月3.7685;2月3.6551;3月3.4703;5月3.2437和8月3.1941。该湿地鸟类多样性动态表现出明显的季节性。  相似文献   
80.
Abstract:  A preliminary stage in developing comprehensive conservation plans involves identifying areas used by the organisms of interest. The areas used by migratory land birds during temporal breaks in migration (stopover periods) have received relatively little research and conservation attention. Methodologies for identifying stopover sites across large geographic areas have been, until recently, unavailable. Advances in weather-radar technology now allow for evaluation of bird migration patterns at large spatial scales. We analyzed radar data (WSR-88D) recorded during spring migration in 2000 and 2001 at 6 sites in the Great Lakes basin (U.S.A.). Our goal was to link areas of high migrant activity with the land-cover types and landscape contexts corresponding to those areas. To characterize the landscapes surrounding stopover locations, we integrated radar and land-cover data within a geographic information system. We compared landscape metrics within 5 km of areas that consistently hosted large numbers of migrants with landscapes surrounding randomly selected areas that were used by relatively few birds during migration. Concentration areas were characterized by 1.2 times more forest cover and 9.3 times more water cover than areas with little migrant activity. We detected a strong negative relationship between activity of migratory birds and agricultural land uses. Examination of individual migration events confirmed the importance of fragments of forested habitat in highly altered landscapes and highlighted large concentrations of birds departing from near-shore terrestrial areas in the Great Lakes basin. We conclude that conservation efforts can be more effectively targeted through intensive analysis of radar imagery.  相似文献   
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