全文获取类型
收费全文 | 308篇 |
免费 | 4篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 104篇 |
废物处理 | 6篇 |
环保管理 | 35篇 |
综合类 | 67篇 |
基础理论 | 52篇 |
污染及防治 | 19篇 |
评价与监测 | 25篇 |
社会与环境 | 3篇 |
灾害及防治 | 12篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 1篇 |
2021年 | 11篇 |
2020年 | 18篇 |
2019年 | 11篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 17篇 |
2014年 | 24篇 |
2013年 | 12篇 |
2012年 | 10篇 |
2011年 | 29篇 |
2010年 | 8篇 |
2009年 | 17篇 |
2008年 | 12篇 |
2007年 | 6篇 |
2006年 | 14篇 |
2005年 | 11篇 |
2004年 | 8篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 14篇 |
1998年 | 9篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有323条查询结果,搜索用时 15 毫秒
101.
Florian Jeltsch Kirk A. Moloney Katrin KörnerNiels Blaum 《Agriculture, ecosystems & environment》2011,145(1):49-58
While several empirical and theoretical studies have clearly shown the negative effects of climate or landscape changes on population and species survival only few of them addressed combined and correlated consequences of these key environmental drivers. This also includes positive landscape changes such as active habitat management and restoration to buffer the negative effects of deteriorating climatic conditions. In this study, we apply a conceptual spatial modelling approach based on functional types to explore the effects of both positive and negative correlations between changes in habitat and climate conditions on the survival of spatially structured populations. We test the effect of different climate and landscape change scenarios on four different functional types that represent a broad spectrum of species characterised by their landscape level carrying capacity, the local population turnover rates at the patch level (K-strategies vs. r-strategies) and dispersal characterstics. As expected, simulation results show that correlated landscape and climatic changes can accelerate (in case of habitat loss or degradation) or slow down (in case of habitat gain or improvement) regional species extinction. However, the strength of the combined changes depends on local turnover at the patch level, the overall landscape capacity of the species, and its specific dispersal characteristics. Under all scenarios of correlated changes in habitat and climate conditions we found the highest sensitivity for functional types representing species with a low landscape capacity but a high population growth rate and a strong density regulation causing a high turnover at the local patch level.The relative importance of habitat loss or habitat degradation, in combination with climate deterioration, differed among the functional types. However, an increase in regional capacity revealed a similar response pattern: For all types, habitat improvement led to higher survival times than habitat gain, i.e. the establishment of new habitat patches. This suggests that improving local habitat quality at a regional scale is a more promising conservation strategy under climate change than implementing new habitat patches. This conceptual modelling study provides a general framework to better understand and support the management of populations prone to complex environmental changes. 相似文献
102.
Coasean arguments against the Pigouvian perspective are well established. A central tenet in this criticism argues that a Pigouvian tax may be a source of inefficiency: if parties were to bargain in the presence of a Pigouvian tax, (allocative) inefficiencies would occur—the so-called Buchanan–Stubblebine–Turvey Theorem. By analyzing a Coasean environment where the appropriation of property rights is costly, we show Coasean bargaining in the presence of a pre-existing (Pigouvian) tax may be superior. This has implications for policy where dual regulatory environments exist, such as regulation at the state and federal level, as well as environmental liability and litigation. 相似文献
103.
We study the introduction of new technologies when their costs are subject to idiosyncratic uncertainty and can only be fully learned through individual experience. We set up a dynamic model of clean experience goods that replace old polluting consumption options and show how optimal regulation evolves over time. In our base setting where social and private learning incentives coincide, the optimal tax on the polluting consumption is increasing over time. We show, however, that if social and private learning incentives diverge because the private discount rate exceeds the social discount rate, it may be optimal to temporarily increase the tax rate beyond net marginal external damages to induce more learning before reducing the tax rate to the steady state level. Alternatively, one could complement the tax with subsidies for first-time users which can be phased out over time. Similar results apply if consumers have biased expectations. We therefore give a rationale for introductory subsidies on new, clean technologies and non-monotonic tax paths from a perspective of consumer learning. 相似文献
104.
Aleksandar D. Slaev Diliana Daskalova 《Journal of Environmental Policy & Planning》2020,22(4):486-500
ABSTRACT This paper contributes to the debate on whether private or common property rights are better for advancing the sustainable management of natural resources. This contest between public and private ownership is often exaggerated, we claim, because in the real world, complex entitlements with varying degrees of privateness/publicness prevail. Property rights belonging to families, companies, clubs, corporations, and communities are simultaneously common to the members/shareholders and private to the entities. We call these entitlements private-common entitlements. When we acknowledge this complexity, it becomes evident that neither private nor common ownership rights are alone responsible for resource depletion. Instead, depletion is caused by freeriding or evading the payment of the full price of natural resources. This invites Coase’s solution to resource allocation. Therefore, the key problem is whether and how Coasean bargaining is employed to allocate ownership over resources threatened by depletion. We contribute to the debate by showing that Coase’s approach promotes not only economically efficient but also ecologically sustainable resource management. Often, this approach would lead to the establishment of largely private property or control rights by largely collective/public entities. We apply this theoretical framework to the development of a ski resort in Pirin Mountain, Bulgaria. 相似文献
105.
An experimental testing program designed to evaluate the opening stability characteristics of direct acting pressure relief valves (PRV) in gas/vapor service is described. Three different valve sizes from each of three different manufacturers were tested at two different set pressures to determine their opening characteristics (disk lift vs. time). The valves were tested with several different lengths of inlet piping as well as with and without discharge piping to determine the conditions under which unstable operation (chatter) would occur. Part I of this program described a mathematical model for predicting the dynamic response of PRV's, and the data described in this test program were used to evaluate the accuracy of the model, as described in Part III of this study to follow. 相似文献
106.
Reyer Gerlagh Snorre Kverndokk Knut Einar Rosendahl 《Journal of Environmental Economics and Management》2014
We study the optimal time path for clean energy innovation policy. In a model with emission reduction through clean energy deployment, and with R&D increasing the overall productivity of clean energy, we describe optimal R&D policies jointly with emission pricing policies. We find that while emission prices can be set at the Pigouvian level independently of innovation policy, the optimal level of R&D subsidies and patent lifetime change with the stages of the climate problem. In the early stages of clean energy development, innovators find it more difficult to capture the social value of their innovations. Thus, for a given finite patent lifetime, optimal clean energy R&D subsidies are initially high, but then fall over time. Alternatively, if research subsidies are kept constant, the optimal patent lifetime should initially be long and fall over time. 相似文献
107.
Olivier Ubrich Balasubrahmanyan Srinivasan Pablo Lerena Dominique Bonvin Francis Stoessel 《Journal of Loss Prevention in the Process Industries》1999,12(6):814-493
Maximising the yield of the second order reaction (2-butanol+propionic anhydride) by manipulating the inlet flow rate is considered for an isothermal semi-batch process. First a procedure for the determination of the kinetic parameters using coupled spectroscopic and calorimetric methods is presented. Then an optimisation of the reaction system is performed numerically and verified experimentally. Constraints on the amount of heat produced and on the temperature attainable in the case of cooling failure are imposed for safety consideration. 相似文献
108.
The growing demand for natural gas has pushed oil and gas exploration to more isolated and previously untapped regions around the world where construction of LNG processing plants is not always a viable option. The development of FLNG will allow floating plants to be positioned in remote offshore areas and subsequently produce, liquefy, store and offload LNG in the one position. The offloading process from an FLNG platform to a gas tanker can be a high risk operation. It consists of LNG being transferred, in hostile environments, through loading arms or flexible cryogenic hoses into a carrier which then transports the LNG to onshore facilities. During the carrier's offloading process at onshore terminals, it again involves risk that may result in an accident such as collision, leakage and/or grounding. It is therefore critical to assess and monitor all risks associated with the offloading operation. This study is aimed at developing a novel methodology using Bayesian Network (BN) to conduct the dynamic safety analysis for the offloading process of an LNG carrier. It investigates different risk factors associated with LNG offloading procedures in order to predict the probability of undesirable accidents. Dynamic failure assessment using Bayesian theory can estimate the likelihood of the occurrence of an event. It can also estimate the failure probability of the safety system and thereby develop a dynamic failure assessment tool for the offloading process at a particular FLNG plant. The main objectives of this paper are: to understand the LNG offloading process, to identify hazardous events during offloading operation, and to perform failure analysis (modelling) of critical accidents and/or events. Most importantly, it is to evaluate and compare risks. A sensitivity analysis has been performed to validate the risk models and to study the behaviour of the most influential factors. The results have indicated that collision is the most probable accident to occur during the offloading process of an LNG carrier at berth, which may have catastrophic consequences. 相似文献
109.
110.
The objective of this work is to investigate and model the mutual effects between the dynamic pressure/temperature in the LNG tank and the leakage behavior with external heat fluxes. The results suggest that the pressure and temperature in tank during leakage change with the comparison results between the heat flux consumed in liquid boil-off and the external heat flux supplied. At the liquid leakage stage, when the external heat flux is not very high, the pressure in tank tends to increase significantly, even results in tank explosion. It increases more and more heavily with higher and higher external heat fluxes. At the vapor leakage stage, large amount of vapor spray out, which results in a high generation rate of vapor by the liquid boil-off. The pressure in tank normally decreases to be low, which is unfavorable for the LNG tank explosion. Therefore, at this vapor leakage stage, blocking the leakage hole as soon as possible is not always a right choice for fire fighters. Finally, it is suggested that reducing the heat flux into the tank, either at the liquid leakage stage or in vapor one, is key to the tank safety. 相似文献