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171.
区域大气污染协作治理本质上是以地方政府为主体的横向协作行为,地方政府的协作意愿与行动策略是决定区域协作进程的重要因素。本研究通过构建区域大气污染协作治理的驱动模型,分析影响区域协作进程的关键因素。在此基础上,以长三角区域为例,通过分析大气点源治理、移动源管控、重污染天气应急管理和重大活动空气质量保障等四类协作议题的协作进程及其驱动机制,识别差异化协作进程的形成原因。最后,本文从强化地方政府区域协作考核力度、建立区域大气环境生态补偿机制、加强区域协作机构的组织能力建设和完善区域协作治理的基础性技术支撑等四方面为构建区域大气污染防治长效协作机制提出政策建议。 相似文献
172.
Integrated water management of the Brahmaputra basin: Perspectives and hope for regional development
Water is strongly linked with the overall development framework of the Brahmaputra basin. However, the absence of integrated management of Brahmaputra water resources and lack of coordination among the riparian states constitutes an ongoing threat to future development plans within the basin. Brahmaputra's abundant hydropower potential can help give riparian countries a safer energy future that is the key driving force behind the prospect of potential cooperation. This paper analyses the current status of Brahmaputra water resources and identifies the perspectives of riparian countries regarding the development of the Brahmaputra basin. It also identifies the opportunities for cooperation and regional development through integrated water development and management of the Brahmaputra basin. It is essential to develop an integrated water resources management approach involving all riparians to foster regional development and overcome the prospect of severe water conflict along the Brahmaputra basin. 相似文献
173.
174.
Stephen Michael Dark 《Journal of Environmental Planning and Management》2017,60(12):2122-2132
The precautionary principle is regularly cited in cases that involve development in eco-sensitive locations. We investigated whether the precautionary principle provides the basis for a coherent framework to prevent environmental harm, and does it work in practice? We suggest that, in principle, the precautionary principle makes good sense. In practice, however, it is imprecise in policy and law and fails to fulfil its promise because it is loosely defined and thus lacks substance and clarity. Consequently, it operates in a framework that is ambiguous, leaving it open to manipulation by discretionary powers. To counter such deficiencies, human-induced environmental harm should be formally observed as ‘criminogenic’ and environmental protection prioritised against which other competing priorities (e.g., ‘year on year’ economic growth) are measured. This would overcome the politico-legal obfuscation and contestations of climate change policy that currently impedes the precautionary principle's practical application. 相似文献
175.
高职食品专业校企合作的问题及对策 总被引:1,自引:0,他引:1
校企合作教育是一种充分利用学校与企业等多种不同的教育环境和资源在培养人才方面的优势,培养适应企业需要的应用性专门人才的教育模式,对高职院校培养应用型人才具有重要的意义。但当前高职院校的校企合作中存在如政策法规不健全、合作机制不完善、企业的热情不高等问题,针对这些问题从政府政策、企业和学校三方面对其解决方法提出了建议。 相似文献
176.
我国开展集体林权制度改革以来,林农合作组织的建设和健康发展是亟待解决的重要问题,而合作组织的建设和发展过程实质上是一个博弈过程。本文在充分考虑林农合作特点的基础上构建了个体对群体的两阶段博弈模型,分析了林农合作组织形成和发展中的博弈行为。研究发现,由于各参与方的理性程度不同、林业收益长期性和林业生产的外部性明显,只有保证林农的长期收益、提高对长期收益的认可程度,更要保证林农的当期收益时,合作才能形成,此外,林业的外部性问题是影响合作形成与发展的重要因素。因此,应丰富合作的内容和形式以确保林农的当期收益;加强对林农大户的培训,提高合作组织规范管理的水平;同时加强宣传以提高对长期收益的认可程度,从而提高长期收益;搭便车现象难以避免但应正确对待;各种能降低风险的措施均有利于合作。此外,在合作组织发展的起步阶段,政府是重要的推动力量,应提高政策支持和监督的力度。 相似文献
177.
中国可持续发展战略实施的进展及其趋势 总被引:4,自引:0,他引:4
本文对中国实施可持续发展战略的现状和进展进行了全国的回顾和总结,对未来中国可持续发展的整体态势和主要趋势进行了分析和展望。 相似文献
178.
Mixed messages across multiple trophic levels: the ecology of bark beetle chemical communication systems 总被引:10,自引:0,他引:10
Kenneth F. Raffa 《Chemoecology》2001,11(2):49-65
Summary. Chemical, physiological and behavioral components of pheromone communication have been described for a number of bark beetle
species, yet our understanding of how these signals function under natural conditions remains relatively limited. Development
of ecologically based models is complicated by the multiple functions and sources of variability inherent in bark beetle semiochemistry.
This discussion addresses four ecological issues of chemical signaling in bark beetles: the effects of aggregation on individual
fitness, the possibility of cheating, how plants can defend themselves against herbivores that employ aggregation pheromones,
and the implications of variability in chemical communication systems to predator avoidance. An analysis of published data
from thirteen scolytid – conifer systems indicates that the net benefit and optimal colonization density vary with host condition
and beetle species. When beetles attack live trees, the benefit of cooperative host procurement exceeds losses due to competition
for the limited substrate, at least up to moderate densities. When beetles colonize dead tissue, however, the effect of subsequently
arriving beetles on initial colonizers is almost entirely negative. This suggests that aggregation originated as exploitation
of senders, but evolved into manipulation of receivers. It is also proposed that the optimal colonization density which typifies
each species or population may offer a more objective and less value–laden index of behavior than current labels such as “aggressiveness”.
Beetles can maximize the relative benefits of group attack by incorporating instantaneous measures of host resistance into
their colonization behavior, and by adjusting oviposition with colonization density. This system may provide opportunities
for cheating. However a number of factors may select against a fixed strategy of cheating, including the linkage between tree
allelochemistry and beetle semiochemistry, the reduced quality of substrate available to late arrivers, the short adult lifespans
of most bark beetles, differential exposure to some predators, the difficulty of locating signalers during extensive endemic
periods, and the low costs incurred during host assessment. However, the possibility that beetles employ flexible, density
– dependent strategies deserves heightened attention. The ability of bark beetles to collectively exhaust host defenses poses
a particular problem for plant defense. It is argued here that the ideal defense should include both direct resistance mechanisms
against invading beetles, and indirect mechanisms that inhibit chemical communication. Evidence for the latter mechanism is
explored. The ability of predators to efficiently exploit aggregation pheromones as kairomones in prey finding poses significant
risk to bark beetles. It is proposed that minor alterations in pheromone components may provide colonizers with partial escape
from such natural enemies while maintaining intraspecific functionality. Traditional interpretations emphasized the fidelity
and consistency of pheromones, but under natural conditions chemical signals are modified by unpredictable features of the
biotic and abiotic environment. Although we typically view variation in pheromonal signals as experimental noise or simple
deviations from a population norm, such variation may reflect evolutionary dynamics. Complex ecological interactions may impose
trade-offs between the clarity versus diversity of their signals.
Received 3 July 2000; accepted 8 January 2001 相似文献
179.
Sonia Graham Alexander L. Metcalf Nicholas Gill Rebecca Niemiec Carlo Moreno Thomas Bach Victoria Ikutegbe Lars Hallstrom Zhao Ma Alice Lubeck 《Conservation biology》2019,33(2):275-287
Controlling invasive species presents a public-good dilemma. Although environmental, social, and economic benefits of control accrue to society, costs are borne by only a few individuals and organizations. For decades, policy makers have used incentives and sanctions to encourage or coerce individual actors to contribute to the public good, with limited success. Diverse, subnational efforts to collectively manage invasive plants, insects, and animals provide effective alternatives to traditional command-and-control approaches. Despite this work, there has been little systematic evaluation of collective efforts to determine whether there are consistent principles underpinning success. We reviewed 32 studies to identify the extent to which collective-action theories from related agricultural and environmental fields explain collaborative invasive species management approaches; describe and differentiate emergent invasive species collective-action efforts; and provide guidance on how to enable more collaborative approaches to invasive species management. We identified 4 types of collective action aimed at invasive species—externally led, community led, comanaged, and organizational coalitions—that provide blueprints for future invasive species management. Existing collective-action theories could explain the importance attributed to developing shared knowledge of the social-ecological system and the need for social capital. Yet, collection action on invasive species requires different types of monitoring, sanctions, and boundary definitions. We argue that future government policies can benefit from establishing flexible boundaries that encourage social learning and enable colocated individuals and organizations to identify common goals, pool resources, and coordinate efforts. 相似文献
180.