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1.
Distribution characteristics of nonylphenolic chemicals in Masan Bay environments, Korea 总被引:3,自引:0,他引:3
To understand the distribution characteristics of nonylphenolics and sterols, samples such as in creek water, sea surface water, waste water treatment plant (WWTP) effluent water, sediment and mussel were collected and analyzed. The principal analytes are nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), coprostanol (5beta) and cholestanol (5alpha). All these target pollutants showed 100% detection frequency in all of the samples analyzed. Total concentration of nonylphenolic compounds ranged from 334 to 3628ngl(-1) (average: 1331ngl(-1)) in creek water, from 15 to 36400ngl(-1) (average: 1013ngl(-1)) in sea surface water, from 131 to 2811ngg(-1) dry weight (average: 581ngg(-1) dry weight) in sediment and from 50.5 to 289ngg(-1) dry weight (average: 139ngg(-1) dry weight) in mussel. For water samples, levels of nonylphenolics determined in summer season were higher than those in spring season. Among them, nonylphenol and NP1EO was dominant in creek water and seawater, respectively. The highest concentration was recorded in sediment near a WWTP effluent outlet. And high levels of nonylphenolics and sterols were found in about 3km area surrounding WWTP effluent outlet. Coefficient of linear regression (R(2)) for NP in mussel and in sediment was 0.90. Similarly good correlation (R(2)=0.98) was obtained between concentration in water and in mussel indicating that a steady state has been reached in this bay. The calculated bio concentration factor (BCF=2990) for NP in Masan Bay agrees well with reported values in the literature. 相似文献
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Rangesan Narayanan Dean T. Larson Trevor C. Hughes 《Journal of the American Water Resources Association》1985,21(3):407-416
During the 1976–77 drought, three principal mechanisms were used to reduce water use in Utah communities: price increases, maximum monthly use restrictions, and restrictions on outdoor watering times. A regression model was developed to explain observed changes in water use, with price, type of restriction, household size, and summer rainfall as independent variables. For an average system, a 1 percent increase in price would reduce water use by 0.07 to 0.09 percent. A 1 percent increase in outdoor watering time restriction reduces use by 0.064 to 0.075 percent. A 1 percent increase in quantity restrictions leads to a reduction in water use of 0.014 to 0.054 percent. The effectiveness of rationing policies is influenced by system characteristics. For example, outdoor watering time restrictions were less effective in systems with above average household size and below average monthly use. 相似文献
4.
John E. Keith Rangesan Narayanan 《Journal of the American Water Resources Association》1988,24(6):1247-1256
ABSTRACF: Examination of a series of studies of the economically efficient water allocations in the Upper Colorado River, Yellowstone River, and Great Basins indicate that water is not a serious general physical constraint on the development of energy resources, so long as public institutions do not hinder the exchange of water rights in markets. Energy development will cause limited impacts on other water-using sectors, principally agriculture. There appears to be little reason to develop large-scale water storage facilities, even during periods of reduced water production. Water storage developments appear to be necessary only when institutional constraints severely restrict water rights markets and transfers. 相似文献
5.
Robert Leconte Rangesan Narayanan Trevor C. Hughes 《Journal of the American Water Resources Association》1988,24(2):247-253
ABSTRACT: A general methodology to study the economics of dual water systems (defined here as a separate distribution system for untreated low quality local surface Water for outdoor municipal water supply) is summarized and the application of the method to a rapidly growing city is presented. In the first step, a cost-benefit criterion for evaluating dual systems is developed. The criterion is then extended to a dynamic case where the population to be served increases with time and where the dual system is allowed to expand. The optimal investment time to introduce the dual water supply project is obtained by maximizing social welfare. The model is applied to the city of West Jordan, Utah, where a dual system is currently being proposed. Model results indicate that for the city as a whole dual supply is not economically feasible. However, when the model is applied to a part of the city, it is found feasible and the optimal time to initiate the project would be in the year 1989. 相似文献
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Rangesan Narayanan Bartell C. Jensen A. Bruce Bishop 《Journal of the American Water Resources Association》1977,13(4):691-708
ABSTRACT: A mathematical programming model is proposed to determine economically efficient urban water resource allocation and pricing policy by maximizing the sum of the consumer and producer surplus. The optimization of this nonlinear problem is accomplished by the use of linear programming algorithm. The feasibility of using recycled water for municipal purposes is examined in a planning context. The impact of higher water quality discharge standards on pricing and allocation of water is analyzed and the attractiveness of water reuse option is demonstrated. 相似文献
7.
The electron density, at each carbon atom, of the highest occupied π orbital of thirteen polychlorinated biphenyl (PCB) and one polychlorinated dibenzofuran (PCDF) molecules were calculated and the result was compared with their in vitro and/or in vivo metabolism. We noted that 1. the carbon position at which the frontier electron density was highest was most readily hydroxylated or sulfonated, 2. if the carbon with the highest frontier (π) electrons was occupied by chlorine, either a replacement occurred or the carbon with the next highest electron density was activated for metabolism, 3. due to steric hinderance ‘ortho’ carbons in PCBs were least preferred for such reactions inspite of possessing favorable electron density, 4. this was applicable to both phenobarbitol (PB) - type and 3-methyl cholanthrene (3 MC) - type PCB inducers. Frontier (π) electron density could be an easy guide for understanding the metabolic products of persistent and toxic environmental pollutants in vitro or in vivo and in understanding their environmental fate. 相似文献
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Shyam-Sundar Narayanan Sivanesh Haridoss Karthi Sengodan Thanigaivel Annamalai Stanley-Raja Vethamonickam Chanthini Kanagaraj Muthu-Pandian Ramasubramanian Ramakrishnan Narayanan Kilapavoor Raman Senthil-Nathan Sengottayan 《Environmental science and pollution research international》2021,28(7):7870-7882
Environmental Science and Pollution Research - Impact of chloroform extract of Desmostachya bipinnata was evaluated on armyworm Spodoptera litura (Lepidoptera: Noctuidae). The chloroform extract of... 相似文献
10.
The mole crab Emerita holthuisi Sankolli occurred on two beaches, at Shertallai and at Cochin, in southwest India. Observations on the size-frequency of samples for Shertallai suggest that there were two main periods of recruitment, one in the pre-monsoon,months of February and March, and one during the monsoon, although there may have been some recruitment throught the year. At Cochin, E. holthuisi was present in the pre-monsoon period, but disappeared from the beach during the monsoon. 相似文献