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Induction of phase I biotransformation enzymes is recognized as a hallmark response in fish exposed to coplanar PCBs. Depletions of vitamins A and E and disrupted thyroid hormone and glandular structure secondary to this induction have not yet been examined in an arctic fish species. Arctic grayling were exposed to a single oral dose of 0 (control), 10, 100 or 1000 ng 3,3',4,4'-tetrachlorobiphenyl (TCB) g(-1) bodyweight, a contaminant found in most arctic fish. After 30 and 90 days of exposure, TCB concentrations in tissues, hepatic phase I activity (as ethoxyresorufin-O-deethylase (EROD)), plasma and tissue vitamin A and E concentrations, plasma thyroid hormone levels and thyroid glandular structure were examined. Total plasma osmolality, as an indicator of overall fish health was also monitored. TCB recovery in tissues was low and extremely variable, making comparisons between intended dose groups inappropriate. Therefore, correlation analysis between actual recovered TCB concentrations and biochemical responses was employed. Hepatic EROD activity correlated strongly with liver TCB concentrations. Liver concentrations of vitamin A were altered as a function of TCB concentrations and EROD activity, but plasma vitamin A status was not affected. Vitamin E was depleted by TCB accumulation in blood and EROD induction in liver of males only at 90 days postexposure. Thyroid hormones status and glandular structure were not affected by the short duration TCB exposures used in this experiment. TCB concentrations were correlated with an elevation in plasma osmolality. Results from this experiment indicate that the vitamin status and osmoregulation of arctic grayling exposed to TCB can be compromised. Further studies of field populations exposed to this type of contaminant are warranted.  相似文献   
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In 2000, the Global Water Partnership (GWP) as the main advocate of the concept of Integrated Water Resources Management (IWRM), proposed a definition that is now the reference, despite the ambiguity that persists in its interpretation. At the 2002 World Summit on Sustainable Development, the State representatives committed themselves to launch "plans for integrated water resources management and water efficiency by 2005". Some states immediately honoured this commitment by adopting new national water policies inspired by IWRM principles. Do these implementation plans respond to all the challenges of the IWRM? Or have these states simply reorganized their water resource policies to give an impression of conforming to the framework? In response to these questions, we present a history of IWRM and its conflicting interpretations followed by a case study of reforms enacted in Burkina Faso, to highlight some problems which are inherent to IWRM and how IWRM was transposed on a national scale.  相似文献   
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Erratum     
Murine monoclonal antibodies (mabs) are produced in either mouse ascites or bioreactors (spinner culture, stirred-tank reactor, airlift reactor, hollow-fiber reactor). Human mabs are produced solely in bioreactors. Encapsulation represents a special technology. Hybridoma cells have to be adapted prior to growth in bioreactors. Of crucial importance is the construction of over-producing cell lines by cell- and gene-technological methods. Manipulated cell lines often produce modified mabs.  相似文献   
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New business formation is a formidable and daunting task, which may require personal perseverance and self‐efficacy. If this is indeed the case, will entrepreneurs and non‐entrepreneurs differ on such attributes? Also, if high levels of perseverance and self‐efficacy help entrepreneurs to overcome setbacks, snags, and obstacles, do these positive attributes co‐occur with significant personal costs, such as the tendency to experience regretful thinking? This study uses a random sample of 217 patent inventors in the medical industry (surgery devices) to address these questions. Results indicate that entrepreneurs score significantly higher on self‐efficacy and on two distinct aspects of perseverance—perceived control over adversity and perceived responsibility regarding outcome of adversity—than did non‐entrepreneurs. Also, although entrepreneurs report the same number of regrets, their regrets are stronger and are qualitatively different from those reported by non‐entrepreneurs. These findings suggest that perseverance and self‐efficacy do indeed co‐occur with regretful thinking. Finally, post hoc analysis reveals that the higher the overall perseverance scores of patent inventors, the higher their annual earnings. We conclude by examining the implications for theory, researcher, and practice. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
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The aim of this study was to evaluate the importance of biotransformation of paralytic shellfish toxins during the detoxification process in contaminated oysters. Mathematical models based upon the detoxification patterns of digestive gland and other tissues were developed. It was demonstrated that biotransformations do not seem to play an important role in digestive gland or other tissue detoxification kinetics with our data set. Moreover, different toxin transfers from digestive gland toward other tissues were investigated. No significant transfer was highlighted in our data set. These first conclusions were drawn after comparing the results obtained from 13 biotransformations and identifiable transfer scenarios. Finally, to determine a more robust model, all 12 states corresponding to toxic compounds and tissues were aggregated into a single state model. The best adjustment was obtained with a simple one-compartment model based on total flesh toxicity with elimination rate expressed by a function depending on initial concentrations of GTX3 and GTX2 (i.e. the two major toxic compounds found in contaminated oysters).  相似文献   
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The purpose of this paper is twofold. First, we raise some issues related to the expected dimension of the carbon market. This analysis is based on a survey of model results on the implementation of the Kyoto goal with and without reliance on emissions trading. In particular, we consider both the emissions and the financial implications associated with different trading scenarios. Transfers related to international GHG trading might be equivalent to a 400% increase in foreign direct investment to countries with economies in transition. A closer look at the GHG reductions expected from the developing world also suggests that global models may be overly optimistic in their assessment of the contribution of flexibility mechanisms in meeting the Kyoto emission goals. OECD countries may need to rely more on domestic policies to reduce their emissions than what has so far been projected by global models. Second, we use a simple microeconomic model to test the potential contribution of typical power generation technologies in the context of the Clean Development Mechanism. Projects that are defined as additional in terms of the environment but already profitable can bring about significant results at a relatively low price of certified emission reductions. To assume that the contribution of the CDM will come close to what is projected by global models (both for prices and quantities) is to assume that such projects could be credited under the CDM. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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This study estimates the economic value of externalities related to waste transfer stations in Israel. Most externalities are associated with local disamenities experienced by residents living in close proximity to transfer stations - including noise, odor, litter, vermin, visual intrusion and any associated perceived discomfort. Following the mapping of all active transfer stations in Israel, problematic sites near residential areas were identified. Four of these sites were selected for detailed examination. The study involved estimating the economic value of disamenities using the Hedonic Price Method, which examines the impact of disamenities on property values. The results indicate that the maximum spatial extent of the impact occurs about 2.8km away from a transfer station with an increase of about $5000 in housing price for each additionalkm away from the site. Alternatively, an increase of 1% in the average distance of a house from the local transfer station is associated with a 0.06% rise in the price of the average house. These figures, representing the relationship between changes in environmental quality and property prices, indicate that transfer stations create externalities that should be taken into account in location and clean-up policies for transfer stations as well as in potential compensation policies.  相似文献   
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