全文获取类型
收费全文 | 240篇 |
免费 | 16篇 |
国内免费 | 20篇 |
专业分类
废物处理 | 4篇 |
环保管理 | 73篇 |
综合类 | 35篇 |
基础理论 | 128篇 |
环境理论 | 1篇 |
污染及防治 | 24篇 |
评价与监测 | 3篇 |
社会与环境 | 6篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 11篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 12篇 |
2009年 | 19篇 |
2008年 | 20篇 |
2007年 | 20篇 |
2006年 | 15篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 11篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有276条查询结果,搜索用时 15 毫秒
101.
Rocío A. Pozo Eric G. LeFlore A. Bradley Duthie Nils Bunnefeld Isabel L. Jones Jeroen Minderman O. Sarobidy Rakotonarivo Jeremy J. Cusack 《Conservation biology》2021,35(1):297-306
Conflicts between the interests of agriculture and wildlife conservation are a major threat to biodiversity and human well-being globally. Addressing such conflicts requires a thorough understanding of the impacts associated with living alongside protected wildlife. Despite this, most studies reporting on human–wildlife impacts and the strategies used to mitigate them focus on a single species, thus oversimplifying often complex systems of human–wildlife interactions. We sought to characterize the spatiotemporal patterns of impacts by multiple co-occurring species on agricultural livelihoods in the eastern Okavango Delta Panhandle in northern Botswana through the use of a database of 3264 wildlife-incident reports recorded from 2009 to 2015 by the Department of Wildlife and National Parks. Eight species (African elephants [Loxodonta africana], hippopotamuses [Hippopotamus amphibious], lions [Panthera leo], cheetah [Acinonyx jubatus], African wild dogs [Lycaon pictus], hyenas [Crocuta crocuta], leopards [Panthera pardus], and crocodiles [Crocodylus niloticus]) appeared on incident reports, of which 56.5% were attributed to elephants. Most species were associated with only 1 type of damage (i.e., either crop damage or livestock loss). Carnivores were primarily implicated in incident reports related to livestock loss, particularly toward the end of the dry season (May–October). In contrast, herbivores were associated with crop-loss incidents during the wet season (November–April). Our results illustrate how local communities can face distinct livelihood challenges from different species at different times of the year. Such a multispecies assessment has important implications for the design of conservation interventions aimed at addressing the costs of living with wildlife and thereby mitigation of the underlying conservation conflict. Our spatiotemporal, multispecies approach is widely applicable to other regions where sustainable and long-term solutions to conservation conflicts are needed for local communities and biodiversity. 相似文献
102.
Positive interactions are widely recognized as playing a major role in the organization of community structure and diversity. As such, recent theoretical and empirical works have revealed the significant contribution of positive interactions in shaping species’ geographical distributions, particularly in harsh abiotic conditions. In this report, we explore the joint influence of local dispersal and an environmental gradient on the spatial distribution, structure and function of communities containing positive interactions. While most previous theoretical efforts were limited to modelling the dynamics of single pairs of associated species being mutualist or competitor, here we employ a spatially explicit multi-species metacommunity model covering a rich range of interspecific interactions (mutualism, competition and exploitation) along an environmental gradient. We find that mutualistic interactions dominate in communities with low diversity characterized by limited species dispersal and poor habitat quality. On the other hand, the fraction of mutualistic interactions decreases at the expense of exploitation and competition with the increase in diversity caused by higher dispersal and/or habitat quality. Our multi-species model exemplifies the ubiquitous presence of mutualistic interactions and the role of mutualistic species as facilitators for the further establishment of species during ecosystem assembly. We therefore argue that mutualism is an essential component driving the origination of complex and diverse communities. 相似文献
103.
Size assessment in simulated territorial encounters between male green frogs (Rana clamitans) 总被引:2,自引:0,他引:2
Mark A. Bee Stephen A. Perrill Patrick C. Owen 《Behavioral ecology and sociobiology》1999,45(3-4):177-184
We examined the ability of male green frogs to assess the size of an opponent based on the dominant frequency of their advertisement
call, which is negatively correlated with size, using synthetic stimuli to simulate intruders of different sizes. In one field
playback experiment, we broadcast a pair of stimuli representing a small and a large male; in a second experiment, we broadcast
calls of a medium and a large male. In both experiments, males produced calls with significantly lower dominant frequencies
in response to each stimulus. Contrast analyses revealed that males lowered the dominant frequency of their calls more in
response to the large-male stimulus than in responses to the small- and medium-male stimuli. In the second experiment, males
also responded to the large-male stimulus by calling at higher rates. There were no differences in mean note duration or the
number of moves made toward or around the playback speaker in response to any stimulus. Thus, the frequency of an opponent's
calls elicits a differential modification of calling behavior, primarily in the form of differential dominant frequency alteration,
suggesting that males use dominant frequency to assess the size of opponents during aggressive encounters.
Received: 17 April 1998 / Accepted after revision: 7 October 1998 相似文献
104.
Summary. Research on insect migration has justifiably emphasized females – the so-called “oogenesis-flight syndrome”– since it is
the females that place the eggs into new habitats. The large and small milkweed bugs, Oncopeltus fasciatus and Lygaeus kalmii, respectively, have featured prominently in studies of insect migration and sequestration of host plant toxins for chemical
defense. Here we report that males of these species, and males of another well-studied lygaeine (Neacoryphus bicrucis), produce pheromones in glands usually considered to serve only a defensive role in Heteroptera (the metathoracic scent glands),
and that these pheromones are exploited by a tachinid parasitoid as a host-finding kairomone. The pheromones are mixtures
of C6 and C8 saturated and unsaturated esters reminiscent of lepidopteran pheromones, and the key compound of the O. fasciatus pheromone has now been correctly identified as (E)-2,7-octadienyl acetate. It is proposed that the concept of the oogenesis-flight syndrome for these kinds of insects should
accommodate the role of males in the migration process. The hypothesis is presented that male-produced pheromones play a significant
role in guiding colonization of new habitats in many heteropteran species. In addition, data are presented suggesting that
there is a trade-off between the amount of pheromone produced by colonizing males and the host breadth of the species.
Received 21 December 1998; accepted 15 February 1999. 相似文献
105.
The Precautionary Principle is a legal mechanism for managing the environmental risk arising from incomplete scientific knowledge
of a proposal's impacts. The Precautionary Principle is applied to actions that carry with them the potential for serious
or irreversible environmental change. The model proposed in this paper draws on methods used in a range of disciplines for
modeling (potentially highly nonlinear) interactions between multiple parts of a complex system. These methods have been drawn
together under the common mathematical umbrella of Fitness Landscape Theory. It is argued that the model, called “Environmental
Impact Fitness Landscapes,” allows statements about the sensitivity of the gross effect from a set of impacts to be made when the number of impacts in the set, and/or their degree of interaction, is varied.
It is argued that this can be achieved through identification of “meta” or “emergent” properties of the set itself, without
reference to the specific causal chains determining behavior in specific instances. While such properties are very general,
they may at least allow for the parameterization of the effects of sets of impacts where interactions are highly uncertain
and empirical data severely limited, i.e., situations that would typically invoke the Precautionary Principle. 相似文献
106.
Tao Ya Zhimin Wang Junyu Liu Minglu Zhang Lili Zhang Xiaojing Liu Yuan Li Xiaohui Wang 《Frontiers of Environmental Science & Engineering》2023,17(5):60
107.
Andrea Tony Hermann Karl Hogl Michael Pregernig 《Journal of Environmental Policy & Planning》2017,19(2):168-182
Scientific expertise plays an important role in the complex field of climate policy. Consequently, science–policy interactions have been institutionalized in many countries. However, science–policy arenas vary considerably across countries. Scholars mainly attribute these differences to the influence of specific political cultures. The literature has primarily compared science–policy arenas of countries with diverging political cultures, whereas comparisons of countries with similar political cultures are rare. The latter is especially true for neo-corporatist cultures. Against this background, we compare the climate science–policy arenas of three neo-corporatist countries, Austria, the Netherlands, and Switzerland. Conceptually, we draw on the literature regarding politico-cultural imprints in science–policy arenas. We operationalize national science–policy arenas along four dimensions: the knowledge actors, the organizational formats, the styles of science–policy interactions, and their transparency and visibility. Overall, the three arenas reveal many similarities and much fewer differences. Most similarities correspond to neo-corporatist patterns. However, some similarities consistently deviate from neo-corporatist patterns. Interestingly, almost all differences between the countries match national variations of neo-corporatism. In light of these observations and the specific problem structure of climate policy, we develop research questions to investigate potential explanations for correspondence to and deviation from neo-corporatist patterns. 相似文献
108.
Adsorption of lambda-cyhalothrin and cypermethrin on two typical Chinese soils as affected by copper
Jun Liu Xiaomeng Lü Jimin Xie Yafei Chu Cheng Sun Qian Wang 《Environmental science and pollution research international》2009,16(4):414-422
Background, aim, and scope Pesticides and heavy metals pollution in soil environment has become a serious problem in many countries including China.
Repeated applications of bordeaux mixture (a blend of copper sulfate and calcium hydroxide) and pyrethroid (Pys) insecticides
have led to elevated copper (Cu) and Pys concentrations in vineyard surface soils. However, few studies focused on the interaction
of Pys and heavy metals in the soil environment. Our previous studies had indicated the combined effect of cypermethrin (CPM)
and Cu on soil catalase activity. Also, we had suggested that the addition of Cu could catalyze photo-degradation of CPM and
lambda-cyhalothrin (λ-CHT) in aqueous solution and restrain their degradation in soil. To better understand the potential
influence of Cu on the fate of Pys in the soil environment, the aim of the present work was to examine the effect of Cu on
the adsorption of λ-CHT and CPM on two typical Chinese soils with different soil characteristics, which was one of the key
processes controlling the fate of Pys, and to provide more information about the potential ecological risk of chemicals on
the soil ecosystem. Fourier transform infrared and point charges analysis using the MOPAC program of the Gaussian system were
also used to reveal the probable adsorption mechanism of λ-CHT and CPM on soils.
Materials and methods Two vineyard soils with different properties were chosen as experimental samples. They were sampled from 0 to 10 cm, dried,
and sieved to 2 mm. Each soil was spiked with copper sulfate solution to obtain the following total soil Cu concentrations:
100, 200, 400, 800, and 1,600 mg·kg−1. The treated soils were incubated for 2 weeks and then dried at 20°C. For each soil sample and at each soil Cu concentration,
the adsorption of λ-CHT and CPM was measured using a batch equilibrium method. The concentration of λ-CHT was determined by
HPLC, and the amount of λ-CHT and CPM adsorbed by the soil sample at equilibrium was determined by the difference between
the initial and equilibrium concentrations in solution corrected by the blank adsorption measurement.
Results Without the addition of Cu, the adsorption of λ-CHT and CPM on Black soil is greater than that on Red soil, while the adsorption
of λ-CHT on both soils is significantly stronger than that of CPM. As the soil Cu concentration increased from 19 (or 18;
background) to 1,600 mg·kg−1, the adsorption coefficient (K
d) of λ-CHT decreased from 12.2 to 5.9 L·kg−1 for Red soil, and from 26.1 to 16.8 L·kg−1 for Black soil, whereas the CPM adsorption coefficient in both soils decreased nearly by 100% (K
d decreased from 9.4 to 0.2 L·kg−1 for Red soil and from 16.2 to 0.5 L·kg−1 for Black soil).
Discussion Pys adsorption is a surface phenomenon which depends on the surface area and the organic matter content. Thus, the Black soil,
having higher organic matter and greater surface area than that of the Red soil, show greater adsorption affinity to λ-CHT
and CPM. In our study, the different adsorption affinity of the two Pys was obtained, which was probably attributed to differences
with respect to their physical–chemical properties. Further comparison upon the two Pys was conducted. The point charges of
halogen atoms in the λ-CHT and CPM were calculated, the differences of which probably lead to the fact that λ-CHT has a stronger
binding capacity to soils than CPM. Also, FTIR spectra show that competitive adsorption occurs between CPM and Cu for the
same adsorption sites, which is responsible for the obtained suppression of CPM adsorption affected by Cu.
Conclusions Lambda-cyhalothrin shows a significantly stronger adsorption than cypermethrin on both soils. This phenomenon may be due to
several reasons: (1) λ-CHT has lower solubility and a higher octanol–water partition coefficient value than CPM; (2) λ-CHT
consists of specific isomers, whereas CPM is mixtures of eight different isomers; (3) the chlorine and fluorine atoms in the
λ-CHT have a negative point charge, whereas the chlorine atoms in the CPM have a positive point charge. As the soil Cu concentrations
increased from 19 (or 18) mg·kg−1 to 1,600 mg·kg−1, the adsorption coefficient of λ-CHT and CPM decreased on both soils. This is mainly due to a competition between Cu and
Pys for occupying the adsorption sites on soils. The information from this study have important implications for vineyard
and orchard soils, which often contain elevated levels of Cu and Pys. These results are also useful in assessing the environmental
fate and health effect of λ-CHT and CPM.
Recommendations and perspectives It is important for environmental scientists and engineers to get a better understanding of soil–metal–organic contaminant
interactions. However, pesticide adsorption involves complex processes, and shortcomings in understanding them still restrict
the ability to predict the fate and behavior of pesticide. Therefore, considerable research should be carried out to understand
the mechanism of interaction between Pys and heavy metal on soils clearly. 相似文献
109.
The significance of metal hyperaccumulation for biotic interactions 总被引:13,自引:0,他引:13
Metal hyperaccumulating plants contain very high metal contents. Because of the general toxicity of metals, chemically-mediated
biotic interactions involving hyperaccumulating plants may differ greatly from those of non-hyperaccumulators. Recent research
has demonstrated a defensive function for hyperaccumulated metals against herbivores and pathogens. We predict that some herbivore/pathogen
species have evolved metal tolerance, and suggest that resulting high metal levels in herbivores/pathogens may defend them
against their own predators. Little is known regarding interference and commensal interactions involving hyperaccumulating
plants. Decreased competition may occur through an interference interaction similar to allelopathy, in which enrichment of
metal in the soil under a hyperaccumulator plant's canopy may inhibit another plant species, thus resulting in “elemental
allelopathy”. Metal enrichment of soil under hyperaccumulators also may result in commensalism if another plant species (possibly
another hyperaccumulator) derives a benefit from growing in the metal-enriched soil under the canopy of a hyperaccumulating
overstory plant. It seems likely that high-metal plant litter will host a specialized microflora of decomposers and may affect
nutrient cycling rates. Mutualist biotic interactions also may be affected by the elevated metal contents of hyperaccumulating
species. Mycorrhizal fungi may form mutualisms with hyperaccumulators, but the phenomenon is poorly-explored. The few cases
investigated to date have not detected mycorrhizae. Pollination and seed dispersal mechanisms may require biotic vectors that
might be affected by plant metal content. Hyperaccumulating plants may have solved this dilemma in three ways. First, some
may rely on abiotic vectors for pollen or seed dispersal. Second, biotic vectors used by these species may have varied diets
and thus dilute metal intake to non-toxic levels. Finally, biotic vectors may have evolved tolerance of elevated dietary levels
of metals, and perhaps have become specialists on hyperaccumulator species.
Received 7 November 1997; accepted 28 December 1997. 相似文献
110.
Indriķis Krams 《Behavioral ecology and sociobiology》2000,48(2):147-153
The risk of predation may influence the acquisition of energy and the feeding activity of animals. Feeding activity and body
reserves of wintering great tits Parus major in response to the priority to food access were studied in two areas differing in incidence of predators. The one-predator
area contained sparrowhawks Accipiter nisus only, whereas the two-predator area contained both sparrowhawks and pygmy owls Glaucidium passerinum, whose hunting periods overlap at dawn and dusk. In the two-predator area dominant great tits arrived at feeders significantly
later in the morning, and left earlier in the evening, than their subordinate flock-mates. Hence, feeding day length of dominants
was found to be significantly shorter. The reverse was true for the one-predator area. In addition, dominants carried significantly
greater reserves than subordinates in the area inhabited by two predators. Factors constraining subcutaneous energy reserves
were also studied in removal experiments. After the removal of dominant individuals, subordinate great tits did not reduce
their body reserves in the two predator area. In contrast, subordinate great tits significantly reduced evening body reserves
in the single-predator area. I concluded that the presence of the two predators increases unpredictability in feeding conditions
for great tits. Dominant individuals responded to this by shortening their feeding day and increasing body reserves at dusk.
Received: 8 December 1999 / Received in revised form: 15 March 2000 / Accepted: 31 March 2000 相似文献