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371.
Nicholas L. Ortodossi Ben L. Gilby Thomas A. Schlacher Rod M. Connolly Nicholas A. Yabsley Christopher J. Henderson Andrew D. Olds 《Conservation biology》2019,33(3):580-589
Seascape connectivity (landscape connectivity in the sea) can modify reserve performance in low-energy marine ecosystems (e.g., coral reefs, mangroves, and seagrass), but it is not clear whether similar spatial linkages also shape reserve effectiveness on high-energy, exposed coastlines. We used the surf zones of ocean beaches in eastern Australia as a model system to test how seascape connectivity and reserve attributes combine to shape conservation outcomes. Spatial patterns in fish assemblages were measured using baited remote underwater video stations in 12 marine reserves and 15 fished beaches across 2000 km of exposed coastline. Reserve performance was shaped by both the characteristics of reserves and the spatial properties of the coastal seascapes in which reserves were embedded. Number of fish species and abundance of harvested fishes were highest in surf-zone reserves that encompassed >1.5 km of the surf zone; were located < 100 m to rocky headlands; and included pocket beaches in a heterogeneous seascape. Conservation outcomes for exposed coastlines may, therefore, be enhanced by prioritizing sufficiently large areas of seascapes that are strongly linked to abutting complementary habitats. Our findings have broader implications for coastal conservation planning. Empirical data to describe how the ecological features of high-energy shorelines influence conservation outcomes are lacking, and we suggest that seascape connectivity may have similar ecological effects on reserve performance on both sheltered and exposed coastlines. 相似文献
372.
Jan Nyssen Fikre Fetene Mekete Dessie Getachew Alemayehu Amare Sewnet Alemayehu Wassie Mulugeta Kibret Kristine Walraevens Ben Derudder Bart Nicolai Sofie Annys Firew Tegegne Steven Van Passel Amaury Frankl Elie Verleyen Dereje Teklemariam Enyew Adgo 《Regional Environmental Change》2018,18(7):2089-2104
We have investigated the relevance of the notion of “peripheralism” in the Beles basin. In this lowland border area of Ethiopia, important investments require an evaluation of their socio-economic and ecological impacts in the light of Ethiopia’s Climate-Resilient Green Economy (CRGE) strategy. We contrasted literature of different periods with field observations. In the middle and lower parts of the basin, the Gumuz people traditionally practised shifting cultivation. Resettlement of highlanders is particularly linked to water and land resources. A large irrigation project was initiated in the 1980s, but vegetables and fruits face post-harvest losses. Large water transfers from Lake Tana since 2010 affect the movement of people, the hydrogeomorphology, and ecology of the river. In several parts of the basin, the settlers’ economy now dominates. Many Gumuz became sedentary but maintained their agricultural system, particularly in the south of the lower basin. Land titling allowed allocation of “vacant” areas to transnational or domestic investors. As a result, the semi-natural vegetation is frequently replaced by open cropland, leading to decreased carbon storage and increased soil erosion. This and water abstraction for irrigation jeopardise hydropower production, in contradiction with the CRGE objectives. Despite the recent developments, the contrasts in economic activity make the core-periphery dichotomy to remain actual in the Beles basin. The resettlements and permanent cropping tend to make the upper basin part of the core. However, the installation of a transit road and commercial farms in the lower basin do not allow to consider that a non-peripheral integration has taken place. 相似文献
373.
Feeding marine wildlife as a tourism experience has become a popular means by which to attract both people and wildlife, although
management efforts are still in their infancy. “Stingray City Sandbar” in the Cayman Islands, where visitors can hand feed
free-ranging Southern Stingrays (Dasyatis americana), is a world-famous attraction currently undergoing visitor and wildlife management. One plan is to decrease the amount of
nonnatural food provided by tourists with the intention of decreasing stingray habituation to the artificial food source and
promoting stingray health. However, the effectiveness of this action is uncertain given that neither the extent of squid composition
in the stingray diet nor the degree of nutrient similarity between the fed and natural diets is unknown. We used fatty acid
(FA) profile analysis to address these questions by assessing the serum nonesterified FA composition of fed and unfed stingrays
around the island and compared them with FA profiles of (1) the provisioned food source (squid) and (2) other warm- and cold-water
elasmobranchs (sharks and rays). Our results indicated that fed stingrays were distinct. The FA profiles of the fed stingray
population were expressly different from those of the unfed populations and showed a remarkable similarity to the FA composition
of squid, suggesting that squid is the main food source. The tropical fed stingrays also exhibited essential FA ratios, specific
to both species and habitat, comparable with those of elasmobranchs and squid from cold-water environs, implying that the
provisioned food does not provide a similar nutritional lipid composition to that eaten in the wild. Our results suggest that
FA profiles are a valuable indicator for the management and monitoring of fed Southern Stingrays because they can be used
to assess differences in diet composition and provide an index of nutritional similarity. Our findings are currently being
used by Caymanian stakeholders in designing practical management actions for their wildlife attraction. 相似文献
374.
Kjelland ME Kreuter UP Clendenin GA Wilkins RN Wu XB Afanador EG Grant WE 《Environmental management》2007,40(2):231-244
Fragmentation of family-owned farms and ranches has been identified as the greatest single threat to wildlife habitat, water
supply, and the long-term viability of agriculture in Texas. However, an integrative framework for insights into the pathways
of land use change has been lacking. The specific objectives of the study are to test the hypotheses that the nonagricultural
value (NAV) of rural land is a reliable indicator of trends in land fragmentation and that NAV in Texas is spatially correlated
with population density, and to explore the idea that recent changes in property size patterns are better represented by a
categorical model than by one that reflects incremental changes. We propose that the State-and-Transition model, developed
to describe the dynamics of semi-arid ecosystems, provides an appropriate conceptual framework for characterizing categorical
shifts in rural property patterns. Results suggest that changes in population density are spatially correlated with NAV and
farm size, and that rural property size is spatially correlated with changes in NAV. With increasing NAV, the proportion of
large properties tends to decrease while the area represented by small properties tends to increase. Although a correlation
exists between NAV and population density, it is the trend in NAV that appears to be a stronger predictor of land fragmentation.
The empirical relationships established herein, viewed within the conceptual framework of the State-and-Transition model,
can provide a useful tool for evaluating land use policies for maintaining critical ecosystem services delivered from privately
owned land in private land states, such as Texas. 相似文献
375.
Hung WT Tam KM Lee CP Chan LY Cheung CS 《Journal of the Air & Waste Management Association (1995)》2006,56(10):1420-1430
Zhuhai, a relatively less developed city on the western coast of the Pearl River Delta (PRD) of China, is planning to undergo major development in coming years. A Hong Kong-Zhuhai-Macao Bridge project has been approved by the Central Government of China. The project will have great impact on the driving pattern and vehicular emissions to the city. This baseline study collected speed-time data of two instrumented private cars in morning and evening periods, as well as a daytime nonpeak period of >10 consecutive days in the spring and winter of 2003. The authors used the microwave speed sensor and global positioning system installed in the instrumented cars and used car-chasing technique to perform the data collection. They used the statistical package SPSS to assess the consistency, as well as to evaluate the variability of the data. Nine parameters, namely, average speed, average running speed, average acceleration rate, average deceleration rate, mean length of a driving period, time proportions of driving modes, average number of acceleration-deceleration changes, root mean square acceleration, and positive acceleration kinetic energy are calculated to represent the driving characteristics. A driving cycle for private cars was developed. If emission tests were conducted using the Zhuhai driving cycle, the level of vehicle emissions measured is likely to be in between that of the Federal Test Procedure (FTP) cycle and the Melbourne Peak cycle. 相似文献
376.
377.
Moncef Zairi Abdelwaheb Aydi Hamed Ben Dhia 《Journal of Material Cycles and Waste Management》2014,16(1):141-150
A survey was conducted between 2006 and 2008 in order to identify municipal solid waste (MSW) composition and its influence on leachate generation and to assess the amount of biogas yield from the Jebel Chakir landfill in Tunis City. The organic fraction was the predominant compound in the MSW, followed by paper, fine, plastic, leather, rubber, metal, textile, glass and ceramic. The average MSW moisture content varies from 60 % in the wet season to 80 % in the dry one. The recognised MSW composition is well representative if compared to that of cities in developing countries. A large leachate quantity is produced in the landfill of Jebel Chakir, despite the negative water balance of the site. Based on the annual MSW landfilled quantities and using the LandGEM model, the expected peak landfill gas (LFG) production is estimated to occur 1 year after the landfill closure with a rate of 3.53 × 107 m3/year. The analysis of the potential conversion of LFG to electric energy shows it at a total LFG-to-electricity energy of around 257 GWh with a heating value of 4,475 kcal/m3 based on an LFG collection efficiency of 33 % and energy efficiency of 33 % giving an economic feasibility for a 10 MW power plant. 相似文献
378.
To help stem the continuing decline of biodiversity, effective transfer of technology from resource‐rich to biodiversity‐rich countries is required. Biodiversity technology as defined by the Convention on Biological Diversity (CBD) is a complex term, encompassing a wide variety of activities and interest groups. As yet, there is no robust framework by which to monitor the extent to which technology transfer might benefit biodiversity. We devised a definition of biodiversity technology and a framework for the monitoring of technology transfer between CBD signatories. Biodiversity technology within the scope of the CBD encompasses hard and soft technologies that are relevant to the conservation and sustainable use of biodiversity, or make use of genetic resources, and that relate to all aspects of the CBD, with a particular focus on technology transfer from resource‐rich to biodiversity‐rich countries. Our proposed framework introduces technology transfer as a response indicator: technology transfer is increased to stem pressures on biodiversity. We suggest an initial approach of tracking technology flow between countries; charting this flow is likely to be a one‐to‐many relationship (i.e., the flow of a specific technology from one country to multiple countries). Future developments should then focus on integrating biodiversity technology transfer into the current pressure‐state‐response indicator framework favored by the CBD (i.e., measuring the influence of technology transfer on changes in state and pressure variables). Structured national reporting is important to obtaining metrics relevant to technology and knowledge transfer. Interim measures, that can be used to assess biodiversity technology or knowledge status while more in‐depth indicators are being developed, include the number of species inventories, threatened species lists, or national red lists; databases on publications and project funding may provide measures of international cooperation. Such a pragmatic approach, followed by rigorous testing of specific technology transfer metrics submitted by CBD signatories in a standardized manner may in turn improve the focus of future targets on technology transfer for biodiversity conservation. 相似文献
379.
380.