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21.
To disentangle genetic and environmental influences on phenotypic traits that influence maturation of fish, it would be useful to predict the expected change due to environment alone to compare with observations. This requires a realistically scaled, species-specific life history model of environmentally determined variation in individual growth and maturation. In this study, inter-annual variability in the proportion of mature haddock in the west North Sea was predicted using a stochastic, individual-based simulation model incorporating a temperature-dependent maturation threshold. This species and region are particularly relevant to the debate about the relative importance of genetic and climate change because North Sea haddock have experienced both high fishing mortality and substantial warming in recent decades. Using observed temperatures in combination with temperature-dependent models for growth and maturation, the simulation model predicted year-to-year variation in length and maturity at age expected for cohorts produced from 1979 to 2006. The simulated proportions mature at age 2 were then compared to the observed proportions in an annual bottom trawl survey. Although the model explained much of the high-frequency variation in maturation, the simulated time trend under-represented the rate of increase in the observed trend in proportions mature. This inability of the temperature-dependent life history model to predict the magnitude of change appears consistent with a long-term decline in the maturation threshold. This result provides indirect support for a genetic change in a key life history trait. 相似文献
22.
Eliciting expert knowledge in conservation science 总被引:2,自引:0,他引:2
Martin TG Burgman MA Fidler F Kuhnert PM Low-Choy S McBride M Mengersen K 《Conservation biology》2012,26(1):29-38
Expert knowledge is used widely in the science and practice of conservation because of the complexity of problems, relative lack of data, and the imminent nature of many conservation decisions. Expert knowledge is substantive information on a particular topic that is not widely known by others. An expert is someone who holds this knowledge and who is often deferred to in its interpretation. We refer to predictions by experts of what may happen in a particular context as expert judgments. In general, an expert-elicitation approach consists of five steps: deciding how information will be used, determining what to elicit, designing the elicitation process, performing the elicitation, and translating the elicited information into quantitative statements that can be used in a model or directly to make decisions. This last step is known as encoding. Some of the considerations in eliciting expert knowledge include determining how to work with multiple experts and how to combine multiple judgments, minimizing bias in the elicited information, and verifying the accuracy of expert information. We highlight structured elicitation techniques that, if adopted, will improve the accuracy and information content of expert judgment and ensure uncertainty is captured accurately. We suggest four aspects of an expert elicitation exercise be examined to determine its comprehensiveness and effectiveness: study design and context, elicitation design, elicitation method, and elicitation output. Just as the reliability of empirical data depends on the rigor with which it was acquired so too does that of expert knowledge. 相似文献
23.
Mark H. Garnett Iain P. Hartley 《Atmospheric environment (Oxford, England : 1994)》2010,44(7):877-883
Radiocarbon (14C) analysis of atmospheric CO2 can provide information on CO2 sources and is potentially valuable for validating inventories of fossil fuel-derived CO2 emissions to the atmosphere. We tested zeolite molecular sieve cartridges, in both field and laboratory experiments, for passively collecting atmospheric CO2. Cartridges were exposed to the free atmosphere in two configurations which controlled CO2 trapping rate, allowing collection of sufficient CO2 in between 1.5 and 10 months at current levels. 14C results for passive samples were within measurement uncertainty of samples collected using a pump-based system, showing that the method collected samples with 14C contents representative of the atmosphere. δ13C analysis confirmed that the cartridges collected representative CO2 samples, however, fractionation during passive trapping means that δ13C values need to be adjusted by an amount which we have quantified. Trapping rate was proportional to atmospheric CO2 concentration, and was not affected by exposure time unless this exceeded a threshold. Passive sampling using molecular sieve cartridges provides an easy and reliable method to collect atmospheric CO2 for 14C analysis. 相似文献
24.
S. T. Garnett S. H. M. Butchart G. B. Baker E. Bayraktarov K. L. Buchanan A. A. Burbidge A. L. M. Chauvenet L. Christidis G. Ehmke M. Grace D. G. Hoccom S. M. Legge I. Leiper D. B. Lindenmayer R. H. Loyn M. Maron P. McDonald P. Menkhorst H. P. Possingham J. Radford A. E. Reside D. M. Watson J. E. M. Watson B. Wintle J. C. Z. Woinarski H. M. Geyle 《Conservation biology》2019,33(2):456-468
Although evidence-based approaches have become commonplace for determining the success of conservation measures for the management of threatened taxa, there are no standard metrics for assessing progress in research or management. We developed 5 metrics to meet this need for threatened taxa and to quantify the need for further action and effective alleviation of threats. These metrics (research need, research achievement, management need, management achievement, and percent threat reduction) can be aggregated to examine trends for an individual taxon or for threats across multiple taxa. We tested the utility of these metrics by applying them to Australian threatened birds, which appears to be the first time that progress in research and management of threats has been assessed for all threatened taxa in a faunal group at a continental scale. Some research has been conducted on nearly three-quarters of known threats to taxa, and there is a clear understanding of how to alleviate nearly half of the threats with the highest impact. Some management has been attempted on nearly half the threats. Management outcomes ranged from successful trials to complete mitigation of the threat, including for one-third of high-impact threats. Progress in both research and management tended to be greater for taxa that were monitored or occurred on oceanic islands. Predation by cats had the highest potential threat score. However, there has been some success reducing the impact of cat predation, so climate change (particularly drought), now poses the greatest threat to Australian threatened birds. Our results demonstrate the potential for the proposed metrics to encapsulate the major trends in research and management of both threats and threatened taxa and provide a basis for international comparisons of evidence-based conservation science. 相似文献
25.
Michael J. Manfredo Tara L. Teel Andrew W. Don Carlos Leeann Sullivan Alan D. Bright Alia M. Dietsch Jeremy Bruskotter David Fulton 《Conservation biology》2020,34(6):1549-1559
We introduced a multilevel model of value shift to describe the changing social context of wildlife conservation. Our model depicts how cultural-level processes driven by modernization (e.g., increased wealth, education, and urbanization) affect changes in individual-level cognition that prompt a shift from domination to mutualism wildlife values. Domination values promote beliefs that wildlife should be used primarily to benefit humans, whereas mutualism values adopt a view that wildlife are part of one's social network and worthy of care and compassion. Such shifts create emergent effects (e.g., new interest groups) and challenges to wildlife management organizations (e.g., increased conflict) and dramatically alter the sociopolitical context of conservation decisions. Although this model is likely applicable to many modernized countries, we tested it with data from a 2017–2018 nationwide survey (mail and email panel) of 43,949 residents in the United States. We conducted hierarchical linear modeling and correlational analysis to examine relationships. Modernization variables had strong state-level effects on domination and mutualism. Higher levels of education, income, and urbanization were associated with higher percentages of mutualists and lower percentages of traditionalists, who have strong domination values. Values affected attitudes toward wildlife management challenges; for example, states with higher proportions of mutualists were less supportive of lethal control of wolves (Canis lupus) and had lower percentages of active hunters, who represent the traditional clientele of state wildlife agencies in the United States. We contend that agencies will need to embrace new strategies to engage and represent a growing segment of the public with mutualism values. Our model merits testing for application in other countries. 相似文献
26.
Robert B. Voas Author Vitae Tara Kelley-Baker Author VitaeAuthor Vitae Radha Vishnuvajjala Author Vitae 《Journal of Safety Research》2009,40(2):77-83
Problem
A substantial proportion of drivers arrested for DUI refuse the BAC test, thereby reducing the likelihood that they will be convicted and potentially increasing the number of high-risk multiple offenders contributing to alcohol-related crashes.Method
This paper reviews the information on the current status of implied-consent laws (which impose a sanction on offenders who refuse the BAC test) in the 50 states and the other relevant traffic safety laws and policies that may influence state refusal rates.Results
Although there appears to be only a weak relationship between state refusal rates and crash rates, there is strong evidence that BAC test refusals significantly compromise the arrest, prosecution, and sentencing of DUI suspects and the overall enforcement of DUI laws in the United States.Discussion
Laws and policies that may reduce the number of refusals are discussed.Impact on industry
Alcohol-related crash injuries are an important cost problem for U.S. industry because of property damage from crashes, crash injuries to employees that raise health costs, or the reduction of time on the job resulting from a highway injury. 相似文献27.
Burger J Gochfeld M Jeitner C Gray M Shukla T Shukla S Burke S 《Environmental monitoring and assessment》2007,128(1-3):311-321
Kelp may be useful as a bioindicator because they are primary producers that are eaten by higher trophic level organisms,
including people and livestock. Often when kelp or other algae species are used as bioindicators, the whole organism is homogenized.
However, some kelp can be over 25 m long from their holdfast to the tip of the blade, making it important to understand how
contaminant levels vary throughout the plant. We compared the levels of arsenic, cadmium, chromium, lead, manganese, mercury
and selenium in five different parts of the kelp Alaria nana to examine the variability of metal distribution. To be useful as a bioindicator, it is critical to know whether levels are
constant throughout the kelp, or which part is the highest accumulator. Kelp were collected on Adak Island in the Aleutian
Chain of Alaska from the Adak Harbor and Clam Cove, which opens onto the Bering Sea. In addition to determining if the levels
differ in different parts of the kelp, we wanted to determine whether there were locational or size-related differences. Regression
models indicated that between 14% and 43% of the variation in the levels of arsenic, cadmium, chromium, manganese, mercury,
and selenium was explained by total length, part of the plant, and location (but not for lead). The main contributors to variability
were length (for arsenic and selenium), location (mercury), and part of the plant (for arsenic, cadmium, chromium and manganese).
The higher levels of selenium occurred at Clam Cove, while mercury was higher at the harbor. Where there was a significant
difference among parts, the holdfast had the highest levels, although the differences were not great. These data indicate
that consistency should be applied in selecting the part of kelp (and the length) to be used as a bioindicator. While any
part of Alaria could be collected for some metals, for arsenic, cadmium, chromium, and manganese a conversion should be made among parts.
In the Aleutians the holdfast can be perennial while the blade, whipped to pieces by winter wave action, is regrown each year.
Thus the holdfast may be used for longer-term exposure for arsenic, cadmium, chromium and manganese, while the blade can be
used for short-term exposure for all metals. Cadmium, lead and selenium were at levels that suggest that predators, including
people, may be at risk from consuming Alaria. More attention should be devoted to heavy metal levels in kelp and other algae from Adak, particularly where they may play
a role in a subsistence diets. 相似文献
28.
Jin-San Kim Tara Sankar Pathak Jung-Ho Yun Ki-Pal Kim Tae-Joon Park Yongae Kim Ki-Jung Paeng 《Journal of Polymers and the Environment》2013,21(1):224-232
Alginate polyurethane hybrid materials are prepared by varying mole ratio of 2, 4-TDI as a di-isocyanate and alginic acid as a polyol in presence of dimethyl sulfoxide (DMSO) as a solvent. FT-IR and 13C one-dimensional (1D) solid state NMR (SSNMR) spectroscopy indicates that alginic acid is converted into alginate-polyurethane hybrid material via urethane linkage. Surface morphology of alginate-polyurethane hybrids changes by varying alginic acid: TDI ratio. The peak at near 221 °C in DSC thermogram of alginic acid (Alg) is shifted to higher temperature in alginate-polyurethane hybrid (Algpu1 and Algpu2). TGA study shows that alginate-polyurethane hybrid prepared using alginic acid: TDI = 1:1 (Algpu2) is more stable than alginic acid: TDI = 1:0.5 (Algpu1) at 300 °C. Kinetic analysis was performed to fit with TGA data, where the entire degradation process has been considered as three consecutive 1st order reactions. This study shows that thermal stability of alginate-polyurethane hybrid material was increased by adjusting mole ratio of 2, 4-TDI and alginic acid. 相似文献
29.
30.
Tara Sankar Pathak Jin San Kim Se-Jong Lee Dae-Jin Baek Ki-Jung Paeng 《Journal of Polymers and the Environment》2008,16(3):198-204
Alginic acid and metal alginates are prepared from fresh algae using extraction method. A FTIR spectrum indicates that alginic
acid is converted into the metal alginate. Comparing calcium and cobalt alginates, asymmetric stretching of free carboxyl
group of calcium alginate at 1630 cm−1 is shifted to 1585 cm−1 in cobalt alginate, due to the change of charge density, radius and atomic weight of the cation, creating a new environment
around the carbonyl group. The strong exothermic peak of alginic acid in DSC thermogram indicates the decomposition of biopolymer,
whereas strong exothermic peak of metal alginate in DSC thermogram attributed to the decomposition of biopolymer and formation
of respective carbonate. Based on DSC study, the decomposition of cobalt alginate occurs at higher temperature comparing to
those of sodium and calcium alginate, which may conclude into the higher stability of cobalt alginate. TGA results reveal
that, cobalt alginate is more stable than calcium and sodium alginate at 300 °C temperature. Surface morphology (at same magnification),
as well as porosity (%) and pore size distribution results change with metals present in different metal alginates. 相似文献