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51.
52.
2015年8月,对秦山岛周边的10个站位进行大型底栖动物定量调查。采用生物多样性指数法和丰度生物量比较法对大型底栖动物群落健康状况进行评价。结果显示,共鉴定大型底栖动物7大类31种,其中软体动物、环节动物各10种,节肢动物5种,脊索动物和棘皮动物各2种,纽虫类和腔肠动物各1种;密度优势类群为软体动物,占总密度的35.00%,生物量优势类群为脊索动物,占总生物量的49.35%;优势种分别为红狼牙虾虎鱼(Odontamblyopus rubicundus)、棘刺锚参(Protankyra bidentata)、内卷原盒螺(Eocylichna involuta)和微角齿口螺(Odostomia subangulata)。大型底栖动物密度为站位St.6最大,为115 ind./m2,St.2最小,为20 ind./m2,平均值为70 ind./m2;生物量St.3最大,为197.25 g/m2,St.9最小,为2.56 g/m2,平均值为54.04 g/m2。秦山岛受污染压力、人为活动干扰和生境限制能因素影响,多样性偏低,优势种为耐污的软体动物、脊索动物和棘皮动物,但其主要为K对策种类,大型底栖动物群落受到了轻度干扰,但群落结构仍较为稳定。 相似文献
53.
Magdy I. El-Bana 《Journal of Coastal Conservation》2009,13(1):25-37
Island biogeography theory and nestedness are two relevant and important concepts in biogeography and conservation. However,
their integration and application has not been examined for maintaining or maximizing species diversity, especially in arid
regions. The aim of this study is to investigate the ecological mechanisms related to the observed pattern of floristic diversity
and nestedness in the Lake Bardawil islets on the Mediterranean coast of Sinai Peninsula before the execution of the North
Sinai Agricultural Development Project (NSADP) that will threaten the ecosystem of the lake. Plant species on 15 islets were
identified and categorized into ecological groups related to their life-form, salt tolerance and succulence. Richness of total
plant species and their ecological groups were positively correlated with islet area, number of habitats and elevation, and
negatively with disturbance index. The temperature calculator detected highly significant nestedness for the entire flora
and all ecological groups. Distance from the mainland had no effect on either species richness or nested pattern of total
plant species and their ecological groups. Both the analyses of species richness and nested distribution yielded evidence
for a positive species-area relationship. Although nestedness was detected for the entire plant species and their ecological
groups, many species and islets exhibited idiosyncratic distribution. Idiosyncrasies could be mainly attributed to demographic
stochasticity which is an important character for species interaction and diversity maintenance in arid regions. Therefore,
in developing conservation strategies for the Lake Bardawil islets, it is important to incorporate spatial and temporal stability
of populations. 相似文献
54.
G. A. Klevezal A. E. Bakhur A. A. Sokolov V. A. Serezhenkov N. L. Krushinskaya 《Russian Journal of Ecology》2001,32(2):110-116
The results of the electron paramagnetic resonance (EPR) analysis of pure tooth enamel and the data on the radionuclide content in bones were used for estimating the radiation load on reindeer that lived on Wrangel Island in the 1970s and early 1980s. Based on the measurements of the lower jaws, some biological parameters of the Wrangel reindeer population were estimated and compared with those in the Novaya Zemlya and Taimyr populations. Changes in only two of these parameters—the degree of root cementum resorption and animal life span–might be attributed to the effect of the radiation load. 相似文献
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57.
Classic island biogeographic theory predicts that equilibrium will be reached when immigration and extinction rates are equal.
These rates are modified by number of species in source area, number of intermediate islands, distance to recipient island,
and size of intermediate islands. This general model has been variously modified and proposed to be a stochastic process with
minimal competitive interaction or heavily deterministic. Predictive models of recovery (regardless of the end point chosen)
have been based on the appropriateness of the MacArthur-Wilson models.
Because disturbance frequency, severity, and intensity vary in their effect on community dynamics, we propose that disturbance
levels should first be defined before evaluating the applicability of island biogeographical theory. Thus, we suggest a classification
system of four disturbance levels based on recovery patterns by primary and secondary succession and faunal organization by
primary (invasion of vacant areas) and secondary (remnant of previous community remains) processes.
Level 1A disturbances completely destroy communities with no upstream or downstream sources of colonizers, while some component
of near surface interstitial or hyporheic flora and fauna survive level 1B disturbances. Recovery has been reported to take
from five years to longer than 25 years, when most invading colonists do not have an aerial form.
Level 2 disturbances destroy the communities but leave upstream and downstream colonization sources (level 2A) and, sometimes,
a hyporheic pool of colonizers (level 2B). Recovery studies have indicated primary succession and faunal structuring patterns
(2A) with recovery times of 90–400 days or secondary succession and faunal structuring patterns (2B) with recovery times of
40–250 days.
Level 3 disturbances result in reduction in species abundance and diversity along a stream reach; level 4 disturbances result
in reduction of abundance and diversity in discrete patches. Both disturbance types lead to secondary succession and secondary
faunal organization. Recovery rates can be quite rapid, varying from less than 10 days to 100 or more days.
We suggest that island biogeographical models seem appropriate to recovery by secondary processes after level 3 and 4 disturbances,
where competition may be an important organizing factor, while models of numerical abundance and resource tracking are probably
of better use where community development is by primary succession (levels 1 and 2).
Development of predictive recovery models requires research that addresses a number of fundamental questions. These include
the role of hydrologic patterns on colonization dynamics, the role of nonaerial colonizers in recovery from level 1 disturbances,
and assessment of the impact of changes in the order of invasion by colonizers of varying energetic efficiencies. Finally,
we must be able to assemble these data and determine whether information that guides community organization at one level of
disturbance can provide insights into colonization dynamics at other levels. 相似文献
58.
本文依据生态学理论对海岛土地及土地系统生态功能进行了重新的认识,并探讨了海岛土地系统生态设计的依据、原则和模式.设计中强调以土地系统生态保护性功能为主体,以海岛土地系统高层次调合发展作为海岛建设的最终目标. 相似文献
59.
张哲 《辽宁城乡环境科技》2006,26(1):1-2
对大连市科研院所、学校、医院及监测、检测、检验、试验等单位的实验室、化验室、试验场等排放污染物和处置情况进行了全面调查统计和分析,指出实验室废水、废气、危险废物未经处理直接外排对环境造成较大的污染隐患,并在分析实验室类污染存在问题的基础上提出实验室类污染的控制对策与管理建议。 相似文献
60.
环厦门海域水色变化的多光谱多时相遥感分析 总被引:3,自引:0,他引:3
采用基于影像光谱信息建立的水质遥感模型对环厦门海域1989~2003年间的水色变化进行了分析.通过对水体及其所含物质的物理光学性质分析,水质遥感模型的建立可以不依赖于和卫星同步的水质采样数据建立水质遥感.这使得遥感对水色分析的应用更容易,而且还可以利用大量卫星存档数据来进行水质的历史变化分析.使用基于可见光和近红外波段反射率创建的模型研究了离水信号和水中物质(悬浮物和浮游植物)的关系.提出了一套可用于Landsat TM/ETM 和SPOT 5影像的水专题处理流程,并用于揭示所研究海域中悬浮物和叶绿素浓度的时空变化规律.研究表明,利用基于影像光谱的水质遥感模型,可以快速有效地揭示长时间范围内水色的时空变化.总的看来,环厦门海域的悬浮物浓度在所研究的时期内,有显著的增加,叶绿素的浓度在局部也有明显的升高.最明显的是,高悬浮物浓度的海域面积所占的比例从1989年的0.2%上升到2003年的10.2%.综合分析表明,九龙江河口所带来的巨量悬浮物是该海域最主要的陆源排海物和污染源,过度的水产养殖是另一个主要的污染因子. 相似文献