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991.
南海北部海域经济水产品的重金属污染及其评价 总被引:18,自引:4,他引:18
调查研究了南海北部海域鱼类、是类、蟹类、头足类和双壳类等5大类经济水产品中的Cu、Pb、Zn、Cd、Cr和Ni。研究结果表明,各类生物的重金属含量差异显著,重金属在鱼虾不同器官组织中的分布是不均衡的。鱼类的重金属含量与其栖息水层有关;除肉食性鱼类的Cd含量较高小,不同食性鱼类重金属含量间的差异不显著;近海鱼类的重金属含量与河口咸淡水鱼类的重金属含量之间无显著差异;鱼类重金属含量的季节变化不明显。游 相似文献
992.
大气中CO2增加引起全球变暖和海平面上升及其对珠江三角洲可能的影响 总被引:1,自引:0,他引:1
本文是根据国内外大量实测数据,说明全世界大气层中二氧化碳不断增多,出现“温室效应”,使全球变暖,近地而大气层气温变化的情况;从而引起海面水温变化,使海洋上冰块瓦和融化,引起海平面上升。按世界各国学者研究的结果,近百年全球近地面大气层气温变化总的趋势是上升,北半球比较明显。海平面孔 有上升的趋势。按近40年中海平面可能上升0.4~1m的预测值,估计了海平面可能对珠江水位、沿海风暴潮潮位及咸潮入侵的影响,进而分析了对珠江三角洲、特别广州可能产生的危害。作者认为全球变暖和海平面上升当前还是一个不确定性问题,宜加强科学研究和实测。 相似文献
993.
南黄海春季海水化学要素的分布特征 总被引:23,自引:2,他引:23
本文根据1996年4月“中韩黄海水循环及物质通量合作研究”项目的调查资料,首次对整个南黄海海域春季海水化学要素的分布特征进行了分析和探讨。结果表明,春季南黄海南部溶解氧含量及分布订受外海暖流水所控制,而中北部则主要受生物及生化活动的影响。 相似文献
994.
本文叙述了我国家养动物多样性的现状以及畜牧业发展中家养动物多样性保护与利用的目标及其效益;提出当前我国家养动物保扩和利用面临的问题;并就家养动物多样性保护和利用提出了7个方面的措施,强调家养动物多样性是促进畜牧业持续发展的前提。 相似文献
995.
The bioeconomic analysis of endangered species without consumptive values can be problematic when analysed with density-dependent models that assume a fixed environment size. Most bioeconomic models use harvest as a control variable, yet when modelling non-harvestable species, frequently the only variable under control of conservationists is the quantity of habitat to be made available. The authors explore the implications of this in a model developed to analyse the potential population recovery of New Zealand’s yellow-eyed penguin. The penguin faces severe competition with man for the terrestrial resources required for breeding and has declined in population to perilously low levels. The model was developed to estimate the land use required for recovery and preservation of the species and to compare the results to current tourism-driven conservation efforts. It is demonstrated that land may serve as a useful control variable in bioeconomic models and that such a model may be useful for determining whether sufficient incentives exist to preserve a species. However, the model may generate less useful results for providing a specific estimate of the optimal allocation of land to such a species. 相似文献
996.
Ecologists frequently note the importance of modelling entire ecosystems rather than individual species, but most bioeconomic models in the current literature focus on a single species. While the mathematical difficulty of modelling multiple species may be substantial, it is important to recognise the implications of the single-species assumption to a model’s results. In this paper, the authors address the economic significance of this assumption through the development of an analytical multiple-species model and demonstrate the importance of ecological interrelationships and economic values to the survival of endangered species. 相似文献
997.
On a small island such as Malta where many developers and policy makers place a large emphasis on social use and develoment
values, which encourages recreational/industrial development, it is often hard to promote the monetary value of coastal conservation
due to strong competition with the large tourism industry. An assessment of the ecological (conservation) and economic (use/development)
values of four popular Maltese bathing areas (Mellieha, St. George’s, Ramla and Ghajn Tuffieha Bay) was carried out by evaluating
their ability to provide a number of functions. This is dependent on the environments’ inherent characteristics within the
context of locally applicable time and space functions. Function Analysis is an innovative technique able to provide a means
for assessing changes in environmental quality of an area and evaluating the sustainability of applied management regimes.
This paper is a first example of an application of the Functional Analysis approach in Malta. Local application of this technique
indicates a need for additional refinement in application to coastal areas. Analysis showed that St. George’s, had the lowest
conservation value, Ramla and Ghajn Tuffieha bay had the highest conservation values, Mellieha Bay had high conservation value
and use/development potential. In this context, conservation value is understood to reflect values of biodiversity, information/knowledge
and environmental quality. 相似文献
998.
Building on IUCN Regional Red Lists to Produce Lists of Species of Conservation Priority: a Model with Irish Bees 总被引:2,自引:1,他引:2
ÚNA FITZPATRICK‡ TOMÁS E. MURRAY† ROBERT J. PAXTON† MARK J. F. BROWN 《Conservation biology》2007,21(5):1324-1332
Abstract: A World Conservation Union (IUCN) regional red list is an objective assessment of regional extinction risk and is not the same as a list of conservation priority species. Recent research reveals the widespread, but incorrect, assumption that IUCN Red List categories represent a hierarchical list of priorities for conservation action. We developed a simple eight-step priority-setting process and applied it to the conservation of bees in Ireland. Our model is based on the national red list but also considers the global significance of the national population; the conservation status at global, continental, and regional levels; key biological, economic, and societal factors; and is compatible with existing conservation agreements and legislation. Throughout Ireland, almost one-third of the bee fauna is threatened (30 of 100 species), but our methodology resulted in a reduced list of only 17 priority species. We did not use the priority species list to broadly categorize species to the conservation action required; instead, we indicated the individual action required for all threatened, near-threatened, and data-deficient species on the national red list based on the IUCN's conservation-actions template file. Priority species lists will strongly influence prioritization of conservation actions at national levels, but action should not be exclusive to listed species. In addition, all species on this list will not necessarily require immediate action. Our method is transparent, reproducible, and readily applicable to other taxa and regions. 相似文献
999.
Allison C. Alberts Jeffrey M. Lemm Andrew M. Perry Lisa A. Morici John A. Phillips 《Behavioral ecology and sociobiology》2002,51(4):324-335
In small, insular populations, behavioral patterns that lead to increased variance in individual reproductive success can
accelerate loss of genetic variation. Over a 1-year period, we documented behavior and hormone levels in a breeding group
of adult Cuban iguanas (Cyclura
nubila) at Guantánamo Bay. Male dominance was associated with body and head size, display behavior, testosterone levels, home-range
size, and proximity to females. Based on their success in agonistic encounters, we ranked males in a linear dominance hierarchy.
During the subsequent breeding season, we conducted a removal experiment in which the five highest-ranking males were temporarily
relocated from the study site. Although we were unable to assess reproductive success directly, previously lower-ranking males
assumed control of vacated territories, won more fights, and increased their proximity to females in the absence of the dominant
males. When it results in greater mating opportunities for otherwise socially suppressed individuals, temporary alteration
of local social structure may help limit erosion of genetic variation in small, insular populations.
Electronic Publication 相似文献
1000.
Evaluation model for developing,implementing, and assessing conservation education programs: Examples from Belize and Costa Rica 总被引:1,自引:0,他引:1
Susan K. Jacobson 《Environmental management》1991,15(2):143-150
Evaluation of conservation education programs can: (1) provide accountability in demonstrating a program's worth, (2) offer
an opportunity for receiving feedback and improving programs, (3) further our understanding of the process of program development,
and (4) promote conservation education by substantiating claims about its benefits. The Planning-Process-Product systems evaluation
model provides feedback needed for making decisions about the development, implementation, and outcome of a program. Planning
evaluation was useful in assessing the needs, goals, opportunities, and constraints of a number of programs in Costa Rica
and Belize, such as a forestry education project and a zoo outreach program. It provided a basis for making planning decisions
incorporating specific objectives, such as the reforestation of a region or a change in knowledge and attitudes in program
participants. Process evaluation provided a Costa Rican sustainable development program with feedback during its implementation
and enabled it to modify and improve its newsletter for local farmers and its ecology classes for school children. Product
evaluation assessed project accomplishments, such as the $700,000 raised by the Children's Rainforest group and the 20 miles
of riparian land under conservation management as part of the Belize Community Baboon Sanctuary project. Outcomes are compared
with the programs original monetary or land management objectives to determine the success of the programs and to provide
feedback for improvement. 相似文献