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811.
Valuation of Ecological Resources and Functions 总被引:8,自引:0,他引:8
Michael J. Scott Gordon R. Bilyard Steven O. Link Carlos A. Ulibarri Howard E. Westerdahl Paolo F. Ricci Harold E. Seely 《Environmental management》1998,22(1):49-68
/ Ecological resources are natural resources that provide certain necessary but overlooked system maintenance functions within ecosystems. Environmental economics is in search of an appropriate analysis framework to determine economic values of such resources. This paper presents a framework that estimates and compiles the components of value for a natural ecosystem. The framework begins with the ecological processes involved, which provide functions within the ecosystem and services valued by humans. We discuss the additive or competive nature of these values, and estimate these values through conventional and unconventional techniques. We apply the framework to ecological resources in a shrub-steppe dryland habitat being displaced by development. We first determine which functions and services are mutually exclusive (e.g., farming vs soil stabilization) and which are complementary or products of joint production (e.g., soil stabilization and maintenance of species). We then apply benefit transfer principles with contingent valuation methodology (CVM), travel cost methodology (TCM), and hedonic damage pricing (HDP). Finally, we derive upper-limit values for more difficult-to-value functions through the use of human analogs, which we argue are the most appropriate method of valuation under some circumstances. The highest values of natural shrub-steppe habitat appear to be derived from soil stabilization.KEY WORDS: Natural resource economics; Ecological economics; Ecological resources; Shrub-steppe; Environmental valuation; Cost; Benefit; Value 相似文献
812.
关于社会因素对灾害的影响 总被引:1,自引:1,他引:0
在分析影响灾害主要因素的基础上,以具体灾害实例着重分析了社会因素对灾害的影响,指出社会因素影响灾害主要通过影响灾害源,承灾体的防、抗灾能力,同时社会经济发展水平对灾害损失也有很大影响。 相似文献
813.
自然灾害与区域经济可持续发展 总被引:4,自引:1,他引:3
运用系统工程理论,研究了自然灾害对区域经济持续发展的影响-对区域经济增长、产业结构、资源与环境及区域间经济联系与合作的影响,并对防灾救灾工作提出了建议. 相似文献
814.
815.
Megan Dailey Alix I. Gitelman Fred L. Ramsey Steve Starcevich 《Environmental and Ecological Statistics》2007,14(1):55-68
Models for the analysis of habitat selection data incorporate covariates in an independent multinomial selections model (McCracken
et al. 1998) Ramsey and Usner 2003 and an extension of that model to include a persistence parameter (2003). In both cases,
all parameters are assumed to be fixed through time. Radio telemetry data collected for habitat selection studies typically
consist of animal relocations through time, suggesting the need for an extension to these models. We use a Bayesian approach
that allows for the habitat selection probabilities, persistence parameter, or both, to change with season. These extensions
are particularly important when movement patterns are expected to differ seasonally and/or when availabilities of habitats
change throughout the study period due to weather or migration. We implement and compare the models using radio telemetry
data for westslope cutthroat trout in two streams in eastern Oregon. 相似文献
816.
In 1990 the Dutch government decided to stop any further long-term landward retreat of the coastline. This policy choice for
a ‘dynamic preservation’ is primarily aimed at safety against flooding and at sustainable preservation of the values and interests
concerning the dunes and beaches. Five years later, a first overview of the benefits and bottlenecks of the new coastal defence
policy could be presented, which was published in the second governmental coastal report ‘Kustbalans 1995’ (coastal balance
1995). This consists of three elements: (1) evaluation of the implementation of ‘dynamic preservation’, (2) the consequences
of several natural and anthropogenic developments in the coastal zone and (3) integrated coastal zone management. The present
report describes experiences of Dutch coastline management and summarizes the main conclusions of the second governmental
report.
The overall conclusion of the evaluation study is that the 1990 choice for ‘dynamic preservation’ was right. Sand supply is
an effective method of coastline maintenance, which also serves functional uses in the beach and dune area. However, nearly
a doubling of the supply volume is necessary to compensate for sand losses in the coastal zone. A more integrated management
of the coastal zone is necessary to find an equilibrium between the interests of socio-economic development and the maintenance
of a natural, dynamic system. 相似文献
817.
Of the three species of hirundine that breed sympatrically across the U.K., one, the barn swallow, has outer tail feathers
elongated into streamers, whereas the other two species, the house martin and the sand martin, do not. The tail streamer of
the barn swallow is regarded as a classic example of a sexually selected trait. Recent evidence, however, has suggested that
streamers may have evolved largely through natural selection for enhanced flight performance and increased maneuverability.
We tested the hypotheses that small streamers (1) increase performance in turning flight, but (2) decrease performance in
flight variables related to velocity. We manipulated the lengths of house martin outer tail feathers and measured changes
in their free-flight performance, using stereo-video to reconstruct the birds" three-dimensional flight paths. Five flight
variables were found to best describe individual variation in flight performance. Of these five, the three variables determining
maneuverability predicted that flight performance would be optimized by a 6- to 10-mm increase in the length of the outer
tail feathers. In contrast, for mean velocity and mean acceleration, extension of the outer tail feathers appears to have
a detrimental effect on flight performance. We suggest that the initial selection pressure for streamers in ancestral short-tailed
"barn swallows" was via natural selection for increased maneuverability. In addition, we propose that the benefits of increased
maneuverability have differed between hirundines in the past, such that the cost of increasing the length of the outer tail
feather has, to date, outweighed the benefits of doing so in streamerless hirundines.
Received: 14 February 2000 / Revised: 2 July 2000 / Accepted 18 July 2000 相似文献
818.
Francesca Gherardi 《Behavioral ecology and sociobiology》2006,59(4):500-510
A study was conducted to determine whether asymmetries in both resource-holding potential (RHP) and resource value (RV) influence
dominance and fighting behavior in the hermit crab Pagurus longicarpus. A total of 120 groups of three crabs were observed for 10 min in four experiments that tested all diverse combinations of
equal/different RHP (i.e. ‘body size’) and equal/different RV (i.e. ‘shell size’ and ‘shell quality’). In a fifth experiment,
dominant and subordinate individuals of the same size category (26 groups) were forced to enter shells of opposite quality
than those previously occupied, and then the behavior of the reconstituted original groups was observed for additional 10 min.
As expected, crabs in lower quality shells were more willing to initiate and to escalate fights. However, their attacks were
directed to any crab of the group, independently of the defender's shell quality, and the fight duration did not vary with
the different value of the resources at stake. This may indicate that P. longicarpus is unable to assess the quality of the shells available in its social environment but bases its tactical decisions during
fights solely on its own resource. This suggestion was confirmed by the change in the fighting behavior of crabs whose shell
quality was experimentally altered. This manipulation induced an overall increase in the intensity of aggression, drastic
modification of crab behavior, and inversion of the hierarchy even though these crabs have had previous experiences of wins/losses
and were familiar to the other members of the group. In this species, large crab size and/or the occupancy of adequate (and
oversized) shells appeared to be the most likely determinant of contest resolution. Individuals seemed to retain a memory
of the previously held resource and behaved accordingly. 相似文献
819.
Temporary natural resource cartels 总被引:1,自引:0,他引:1
Hassan Benchekroun Grard Gaudet Ngo Van Long 《Journal of Environmental Economics and Management》2006,52(3):663-674
We analyze the behavior of a nonrenewable resource cartel that anticipates being forced, at some date in the future, to break up into an oligopolistic market in which its members will then have to compete as rivals. Under reasonable assumptions about the value function of the individual firms in the oligopolistic equilibrium that follows the breakup, we show that the cartel will then produce more over the same interval of time than it would if there were no threat of dissolution, and that its rate of extraction is a decreasing function of the cartel's life; that there are circumstances under which the cartel will attach a negative marginal value to the resource stocks, in which case the rate of depletion will be increasing over time during the cartel phase; that, for a given date of dissolution, the equilibrium stocks allocated to the post-cartel phase will increase as a function of the total initial stocks, whereas those allocated to the cartel phase will increase at first, but begin decreasing beyond some level of the total initial stocks. 相似文献
820.
Modeling joint production of wildlife and timber 总被引:2,自引:0,他引:2
Darek J. Nalle Claire A. Montgomery Jeffrey L. Arthur Stephen Polasky Nathan H. Schumaker 《Journal of Environmental Economics and Management》2004,48(3):997
Production of marketed commodities and protection of natural systems often conflict. A focus on only one goal can result in large losses in other goals and may result in inefficient and unsustainable outcomes. In this paper, we develop a method that combines economic and ecological models in a dynamic and spatial analysis to evaluate land use decisions and find cost-effective alternatives for which it is not possible to do better on one objective without harming another objective. The method is demonstrated using timber production and species conservation on a forested landscape over a 100-year planning horizon. Current land use strategies are simulated and compared with cost-effective alternatives. The approach is compared to a static reserve approach, similar to previous studies, and found to produce substantially more efficient management strategies for the case study landscape. 相似文献