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181.
Improving the Evaluation of Conservation Programs 总被引:5,自引:0,他引:5
Devra G. Kleiman Richard P. Reading † Brian J. Miller † Tim W. Clark ‡ J. Michael Scott § John Robinson Richard L. Wallace ‡§ Robert J. Cabin †† and Fred Felleman‡‡ 《Conservation biology》2000,14(2):356-365
Abstract: The evaluation of conservation programs is rare but increasingly important in improving their effectiveness. Regular evaluations of conservation programs and the implementation of recommendations resulting from such assessments are infrequent because of resistance by participants and lack of funding. Evaluations may be internal or external, depending on the purpose of the review and how broadly it is focused. We strongly recommend external peer review of long-term complex conservation programs every 5 years, supported by more frequent (annual) internal reviews. Criteria for success must encompass both biological and social measures and include learning and the application of new knowledge to management. Evaluations must also go beyond monitoring to assess the value of the program. We emphasize the need to include the organization and function of a conservation program (the process) in any evaluation in addition to substantive criteria for success, which usually involve biological measures (numbers). A dysfunctional program organization and process can as effectively cripple a conservation effort as can a major biological catastrophe. We provide examples of different types of conservation program evaluations, including moderated workshops and case-study analysis, and provide advice on the logistics and organization of the review, emphasizing the importance of the evaluation process itself to a successful outcome. One important aspect of an evaluation is having an individual with leadership ability and considerable expertise to organize the format and oversee the review process itself. Second, it is essential at the outset to ensure agreement among the program participants and the review committee on the goals and objectives of the conservation program, what is to be evaluated, and the criteria for defining success. Finally, the best evaluations are inclusive and involve all participants and stakeholders. 相似文献
182.
183.
Summary. A recent investigation showed that the brown seaweed Dictyota menstrualis was unfouled relative to co-occurring seaweeds, and that larvae of fouling invertebrates avoided settling on D. menstrualis due to chemicals on its surface. The secondary metabolites dictyol E and pachydictyol A are among the compounds found on
this alga's surface. In the present study, we tested the effects of specific diterpenes from Dictyota on the survivorship, growth, and development of invertebrate larvae and developing juveniles that could foul seaweeds. Exposure
to dictyol E, dictyol B acetate, pachydictyol A, and dictyodial from Dictyota menstrualis and D. ciliolata caused significant larval mortality, abnormal development, and reduce growth rates for three species of co-occurring invertebrates
when their larvae were forced into contact with these metabolites. Larvae were damaged at metabolite concentrations as low
as 5% of maximum possible surface concentrations of these compounds for the populations of Dictyota we studied. The negative effects of these secondary metabolites on potential foulers, in conjunction with data demonstrating
larval avoidance of dictyol-covered surfaces, suggest that these compounds could function as chemical defenses against fouling,
and could select for larvae that avoid hosts producing these metabolites.
Received 25 May 1998; accepted 22 June 1998. 相似文献
184.
活性污泥中需氧量的研究现状及供氧系统的节能技术 总被引:2,自引:0,他引:2
叙述了国内外活性污泥法中需氧量的研究过程及微孔曝气系统的节能技术,对微孔曝气器与穿孔曝管进行对比,证实前者较后者节电44%. 相似文献
185.
Gluck S Glenn C Logan T Vu B Walsh M Williams P 《Journal of the Air & Waste Management Association (1995)》2003,53(6):749-758
The requirements of the Texas State Implementation Plan of the U.S. Clean Air Act for the Houston-Galveston Ozone Nonattainment Area stipulate large reductions in oxides of nitrogen (NO(x)) emissions. A large number of sources at Dow Chemical Co. sites within the nonattainment area may require the addition of continuous emission monitoring systems (CEMS) for online analysis of NO(x), CO, and O2. At the outset of this work, it was not known whether the analyzers could accurately measure NO(x) as low as 2 ppm. Therefore, NO(x) CEMS analyzers from five different companies were evaluated for their ability to reliably measure NO(x) in the 2-20 ppm range. Testing was performed with a laboratory apparatus that accurately simulated different mixtures of flue gas and, on a limited basis, simulated a dual-train sampling system on a gas turbine. The results indicate that this method is a reasonable approach for analyzer testing and reveal important technical performance aspects for accurate NO(x) measurements. Several commercial analyzers, if installed in a CEMS application with sampling conditioning components similar to those used in this study, can meet the U.S. Environmental Protection Agency's measurement data quality requirements for accuracy. 相似文献
186.
Cyclodiene pesticides: aldrin, isodrin, dieldrin and endrin were dechlorinated by methanogenic granular sludge in spiked batch tests. Initial pesticides concentration was 7 or 9 mgl(-1). Two monodechlorinated analogues were formed during the conversions of aldrin and isodrin. Dieldrin was transformed into two monodechlorinated products as well as into aldrin and two monodechlorinated derivatives of aldrin. In respect of endrin three monodechlorinated and three didechlorinated products were found. The dechlorination of endrin was the most rapid, and was almost complete within 28 days. The dechlorinations of aldrin, isodrin and dieldrin were much slower: over a period of 3 months only 59%, 70% and 88% was transformed, respectively. The amounts of released chloride corresponded 0.54 +/- 0.23, 1.05 +/- 0.25, 1.10 +/- 0.12 of theoretical value for suggested reactions, for aldrin, isodrin and dieldrin respectively. For endrin it was much higher. These transformations did not occur in control samples containing autoclaved granules or in control blank samples without sludge. However, in aldrin spiked blanks, a conversion into a six-chlorinated analogue was found. 相似文献
187.
Soils on sites of former coking and manufactured gas plants as well as on those of blast furnaces are frequently contaminated with cyanides (CN). For assessing the possible risk arising from these hazardous compounds, it is necessary to analyze a considerable number of samples quickly as well as at low costs. Fourier transform infrared (FTIR) spectroscopy has the advantage of being much easier in handling compared to conventional wet-chemical methods for analyzing cyanides. For testing FTIR spectroscopy in the application mentioned above, pure cyanide compounds as well as contaminated purifier waste, blast furnace sludge, and spiked soils were investigated by the reflexion and the transmission techniques. Applicability of the attenuated total reflexion (ATR) technique was limited, since the absorption bands of the crystal used (diamond) overlapped in the range of the cyanide-specific absorption. Although the environmental samples investigated have unfavorable optical properties, results obtained by the transmission technique (KBr pressed pellets) were much better than those obtained by the reflexion technique. Pure cyanide compounds could be distinguished by their IR spectra because their absorption bands of the cyanide-valence vibration differed in position, shape and intensity. The soil matrix did not interfere with either the intensity or the shape and position of the absorption maxima, as concluded from the IR spectra of spiked soil samples. Applying the transmission technique, cyanides are detected at concentrations larger than 500 mg kg?1 CN. However, the signal was low when the cyanide concentration was below 1,000 mg kg?1 CN. The FTIR spectroscopy is capable of detecting cyanide compounds in soils and industrial wastes. Additionally, the method provides information about the cyanide species, which is important in toxicological assessments. FIIR spectroscopy is a suitable method for a first survey and environmental assessment of cyanide contaminated areas. 相似文献
188.
Eggshell colour does not predict measures of maternal investment in eggs of <Emphasis Type="Italic">Turdus</Emphasis> thrushes 总被引:1,自引:0,他引:1
Cassey P Ewen JG Blackburn TM Hauber ME Vorobyev M Marshall NJ 《Die Naturwissenschaften》2008,95(8):713-721
The striking diversity of avian eggshell colour has long fascinated biologists. Recently, it has been proposed that the blue-green colour of some eggs may function as a post-mating sexually selected signal of female phenotypic quality to their mates to induce higher allocation of paternal care. It has been suggested that maternally deposited yolk carotenoids may be the specific aspect of reproductive quality that the female is signalling via eggshell colour. We use the known properties of the thrush visual system (Turdus sp.) to calculate photon capture for the four single cone photoreceptors, and the principal member of the double cone class for eggs in clutches of two introduced European thrush species (Turdus merula and Turdus philomelos) in New Zealand. We show that differences in the avian-perceived colours of individual eggs are not consistently correlated with different measures of maternal investment in the egg. Given the growing extent of the knowledge between maternal quality, parental investment and eggshell pigmentation across avian taxa, we encourage the use of avian perceptual modelling for testing alternative non-signalling explanations for the structural and physiological basis of these relationships. 相似文献
189.
Robert Planqué Anna Dornhaus Nigel R. Franks Tim Kovacs James A. R. Marshall 《Behavioral ecology and sociobiology》2007,61(3):347-356
Animals searching for food, mates, or a home often need to decide when to stop looking and choose the best option found so far. By re-analyzing experimental data from experiments by Mallon et al. (Behav Ecol Sociobiol 50:352–359, 2001), we demonstrate that house-hunting ant colonies are gradually more committed to new nests during the emigration. Early in house-hunting, individual ants were flexibly committed to new nest sites. However, when carrying to a new nest had started, ants hardly ever switched preference. Using a theoretical model based on experimental data, we test at which stage flexible commitment influences speed and accuracy most. We demonstrate that ant colonies have found a good compromise between impatience and procrastination. Early flexibility combined with later rigidity is identically effective as other strategies that include flexible commitment, but it is particularly good when emigration conditions are harsh. 相似文献
190.
Mark?HamannEmail author Tim?S.?Jessop Colin?J.?Limpus Joan?M.?Whittier 《Marine Biology》2005,148(2):427-433
Variation in environmental conditions at a foraging area or at a nesting rookery has the potential to impact reproductive output of green sea turtles (Chelonia mydas) by affecting food resources or the nesting substrate. In this paper we test whether turtles‘ physiological characteristics reflect variation in relevant environmental conditions. We did this by profiling metabolic and hormonal markers among (1) non-vitellogenic females from three different foraging areas and (2) nesting females from different rookeries and breeding seasons. Among the non-vitellogenic females, the highest plasma triglyceride concentrations (4.29 mmol/l) and the lowest plasma cholesterol concentrations (1.27 mmol/l) were found in non-vitellogenic females residing in Moreton Bay during the El Niño year of 1997. Furthermore, during 1997, these Moreton Bay females had higher plasma triglyceride and lower cholesterol concentrations than those recorded in non-vitellogenic females foraging at Heron Reef (triglyceride 1.22 mmol/l and cholesterol 4.53 mmol/l) and Shoalwater Bay (triglyceride 1.69 mmol/l and cholesterol 3.50 mmol/l) in the same year. Among nesting turtles, those nesting at Raine Island had low mean plasma triglyceride concentrations during the high density 1996 nesting season. For those nesting at Heron Island, the mean triglyceride concentrations were the lowest during the 1997 nesting season. This is the first time that hormone and metabolic markers have been used in concert to compare the physiological condition of nesting and foraging sea turtles and its relationship with the environment. Collectively, our data indicate that variation in the environmental conditions at both foraging and nesting areas are reflected at a physiological level. Moreover, our study indicates that turtles feeding during El Niño years are able to attain higher levels of body condition, and that physiological data combined with morphometric data is a useful proxy for assessing the condition of turtles in foraging areas. 相似文献