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281.
Effects of extreme variation in female morph frequencies on the mating behaviour of male damselflies
Janice J. Ting Jessica Bots Felipe Pérez Jvostov Hans van Gossum Thomas N. Sherratt 《Behavioral ecology and sociobiology》2009,64(2):225-236
Female-limited polymorphism is often attributed to selection to avoid excessive male mating attempts. It is encountered in
various taxonomic groups, but is particularly common in damselflies, where one female morph (andromorph) typically resembles
the conspecific male in colour pattern, while the other(s) (gynomorph(s)) do not. Two sets of theories have been proposed
to explain the phenomenon in damselflies, which can be classified as the learned mate recognition (LMR) and male mimicry (MM)
hypotheses. To test predictions of these hypotheses, we evaluated the rate of male sexual response towards female morphs and
conspecific males in the damselfly Nehalennia irene. The LMR hypothesis predicts that males should respond sexually to andromorphs at greater rates in populations containing
a higher relative frequency of andromorphs. The MM hypothesis predicts that males respond more often sexually to both andromorphs
and males as the ratio of andromorphs to males increases. While LMR predicts that the rate of mating attempts towards gynomorphs
should vary, the MM predicts that it should be relatively fixed. On experimentally presenting live specimens to focal males
in five different populations with extreme variation in female morph frequencies, we observed that as the andromorph frequency
and ratio of andromorphs to males increased, the proportion of male mating attempts increased on both andromorphs and males,
whereas it decreased on gynomorphs. While the simplest form of the MM hypothesis is rejected, the results support specific
predictions of both hypotheses and suggest that future studies should not treat these hypotheses as mutually exclusive. 相似文献
282.
Jessica Haapkylä Adrian S. Seymour Orit Barneah Itzchak Brickner Sebastian Hennige David Suggett David Smith 《Marine Biology》2009,156(5):1021-1027
This is the first quantitative study on the prevalence of epizoic Waminoa sp. acoel worms and their association with corals in the Wakatobi Marine National Park (WMNP), South-East Sulawesi, Indonesia.
Three replicate transects were laid on the reef crest, flat and slope at six sites in 2006 and eight sites in 2007. Four of
the sites were common in both years. In total 69 transects were surveyed in 2006, and 87 transects in 2007. A total of 4.8%
of all observed hard corals were associated with acoel worms in 2006 and 2.6% of hard and soft corals in 2007. Acoels were
present on 16 and 21 of the coral taxa studied in 2006 and 2007 respectively. The worms were strongly associated with the
azooxanthellate coral Tubastrea spp. and were rare or absent on the most abundant coral genera Montipora and Porites. The mean number of corals having acoels was highest on reef slopes, whereas acoels were virtually absent on reef flats. Corals
that had a high and a medium cover of worms were more common in 2007 than in 2006. No significant trend in the adaptation
of the zooxanthellae of Waminoa sp. to different depths at different sites was revealed. The impact of the worm on the coral is unknown, but high numbers
may have a shading effect and a negative impact on the coral’s photophysiology. This acoel merits more study of its life cycle,
its photophysiology, and its impact on its host corals.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
283.
A survey of polycyclic musks in selected household commodities from the United States 总被引:9,自引:0,他引:9
Occurrence of the polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN), in wastewater influent and effluent, as well as in surface waters, has been reported. HHCB and AHTN were also reported to occur in human and wildlife tissues. The major sources for HHCB and AHTN to wastewater are thought to be consumer products such as shampoos, deodorants, laundry detergents, and household surface cleaners. However, the levels of HHCB and AHTN in consumer products are not known. For evaluation of the sources of human and environmental exposures, characterization of levels of HHCB and AHTN in consumer products is needed. In this study, we measured concentrations of HHCB (Galaxolide), AHTN (Tonalide), and HHCB-lactone (Galaxolidone) from a variety of consumer products, including perfumes, body lotions, and deodorants. Concentrations of HHCB, AHTN, and HHCB-lactone in consumer products ranged from <5 ng/g to over 4000 microg/g, <5 ng/g to 451 microg/g, and <5 ng/g to 217 microg/g, respectively. The highest concentrations were found in perfumes, body creams and lotions, and deodorants. The results suggest that a wide variety of source materials exist for HHCB and AHTN, and that these materials are used on a daily basis. 相似文献
284.
Nation‐building policies in Timor‐Leste: disaster risk reduction,including climate change adaptation
Jessica Mercer Ilan Kelman Francisco do Rosario Abilio de Deus de Jesus Lima Augusto da Silva Anna‐Maija Beloff Alex McClean 《Disasters》2014,38(4):690-718
Few studies have explored the relationships between nation‐building, disaster risk reduction and climate change adaptation. Focusing on small island developing states, this paper examines nation‐building in Timor‐Leste, a small island developing state that recently achieved independence. Nation‐building in Timor‐Leste is explored in the context of disaster risk reduction, which necessarily includes climate change adaptation. The study presents a synopsis of Timor‐Leste's history and its nation‐building efforts as well as an overview of the state of knowledge of disaster risk reduction including climate change adaptation. It also offers an analysis of significant gaps and challenges in terms of vertical and horizontal governance, large donor presence, data availability and the integration of disaster risk reduction and climate change adaptation for nation‐building in Timor‐Leste. Relevant and applicable lessons are provided from other small island developing states to assist Timor‐Leste in identifying its own trajectory out of underdevelopment while it builds on existing strengths. 相似文献
285.
Polychlorinated biphenyl (PCB) congener concentrations and their distributions were determined for the first time in 12 major rivers of eastern China. It was found that the PCB contamination level in those rivers was relatively low compared to the levels reported in most developing countries. Total amount of PCBs in the river sediments ranged from 10 to 22 ng/g dry weight and dichlorodiphenyldichloroethene (DDE) ranged from 0.89 to 7.62 ng/g. The PCB concentrations were basically homogeneous in different rivers; however, they consistently changed with the percent of total organic carbon (TOC). The PCB concentrations and compositions found in the 12 river sediments were very similar, with the tetra‐ and penta‐ groups as the dominants. Given that distributions and contaminant levels in sediments reflect the number of PCBs, the contamination of the 12 major rivers in eastern China is probably due to atmospheric deposition rather than the point source contamination. 相似文献
286.
Howard W. Mielke Chris R. Gonzales Elise Cahn Jessica Brumfield Eric T. Powell Paul W. MielkeJr 《Environmental geochemistry and health》2010,32(5):431-440
Arsenic (As) ranks first on the 2005 and 2007 hazardous substances priority lists compiled for the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA). This study describes two New Orleans soil As surveys: (1) a survey of
composite soil samples from 286 census tracts and (2) a field survey of soil As at 38 play areas associated with the presence
of chromated-copper-arsenate (CCA)-treated wood on residential and public properties. The survey of metropolitan New Orleans
soils revealed a median As content of 1.5 mg/kg (range <0.2–16.4) and no distinctive differences between the soils of the
city core and outlying areas. Play area accessible soils associated with CCA-treated wood (N = 32) had a median As of 57 mg/kg and 78% of the samples were ≥12 mg/kg, the Louisiana soil As standard. The field survey
of play areas for CCA-treated wood (N = 132 samples at 38 sites) was conducted with a portable energy-dispersive X-ray fluorescence (XRF) analyzer. Seventy-five
of 132 wood samples (56.8%) were deemed CCA-treated wood. Of the 38 play areas surveyed, 14 (36.8%) had CCA-treated wood.
A significant association (Fisher’s exact p-value = 0.348 × 10−6) was found between CCA-treated wood and soil As (N = 75). At one elementary school CCA-treated woodchips (As range 813–1,654 mg As/kg) covered the playgrounds. The situation
in New Orleans probably exists in play areas across the nation. These findings support a precautionary program for testing
soils and wood for hazardous substances at all play areas intended for children. 相似文献
287.
Palestina Guevara-Fiore Jessica Stapley Penelope J. Watt 《Behavioral ecology and sociobiology》2010,64(10):1665-1672
Males vary in the degree to which they invest in mating. Several factors can explain this variation, including differences
in males’ individual condition and the fact that males allocate their energy depending on the context they face in each mating
attempt. Particularly, female quality affects male reproductive success. Here, we studied whether male guppies (Poecilia reticulata) strategically allocated more mating effort, in terms of mating behaviour and male–male competition, when they were matched
with a receptive (R) female than a non-receptive one. In accordance with our prediction, we found that males increased their
mating behaviour when they were with a receptive female. Even though male guppies can inseminate non-receptive females, we
only found high levels of courtship between males that were with a receptive female rather than a non-receptive one. Although
there was little affect of female receptivity on male–male competition, we found that males chased and interrupted courtships
more with receptive females than with non-receptive females regardless of odour. Finally, we also studied whether the sexual
pheromone produced by receptive female guppies is a cue that males use in order to increase their mating effort. We found
that males were more attracted to a female when they perceived the sexual pheromone, but only increased their mating and aggressive
behaviours when females showed receptive behaviour. This strategic increase in mating effort could result in higher male reproductive
success because mating attempts towards receptive females are likely to be less costly and males could have a greater probability
of fertilisation. 相似文献
288.
A study was undertaken to determine whether the isotopic ratios of C and N could be used to uniquely identify municipal solid waste landfill leachate as a source of contamination in the Kaikorai Estuary, Dunedin, New Zealand. Leachate samples were taken from the adjacent Green Island Landfill (GILF), and surface water samples were collected over an 8-month period from the stream and estuary, upstream and downstream of the landfill. Samples were analysed for delta(13)C-dissolved inorganic carbon (DIC), delta(15)N-NO(3)(-), delta(15)N-NH(4)(+), and particulate organic matter (POM) delta(13)C and delta(15)N. Plant material collected along the Kaikorai Stream was analysed for POM delta(13)C and delta(15)N. Leachate was found to have a distinct isotopic signature characterised by a highly enriched delta(13)C-DIC (as much as 16.11+/-0.23 per thousand ) and highly enriched delta(15)N-NH(4)(+) (as much as 27.42+/-0.90 per thousand ). Evidence of leachate contamination was found in the isotopic signatures of downstream delta(13)C-DIC, delta(15)N-NH(4)(+), and delta(13)C and delta(15)N of plant material POM. Other potential sources of enriched delta(13)C-DIC and delta(15)N-NH(4)(+) present in the study area, such as estuarine waters and livestock effluent, were eliminated on the basis of their isotopic characteristics. 相似文献
289.
Motor vehicle crashes are extremely high among young drivers during at least the first year of licensure. Crash risks decline with increased experience, but the more newly licensed teenagers drive, the greater their risk exposure. Hence, the dilemma facing policy makers and parents is how to provide young drivers with driving experience without unduly increasing their crash risk. Graduated driver licensing policies serve to delay licensure and then limit exposure to the highest risk conditions after licensure, allowing young drivers to gain experience only under less risky driving conditions. A similar strategy is needed to guide parents. Parents do not appear to appreciate just how risky driving is for novice drivers and tend to exert less control over their teenage children's driving than might be expected. Recent research has demonstrated that simple motivational strategies can persuade parents to adopt driving agreements and impose greater restrictions on early teen driving. 相似文献
290.