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71.
Multiple sulphatase deficiency was diagnosed in the first trimester of pregnancy by demonstrating markedly reduced activities of arylsulphatases and heparin sulphamidase by direct assays on chorionic villi (CV). The diagnosis was confirmed by assays on cell cultures of villi and fetal skin fibroblasts. Two further pregnancies of this mother were monitored similarly and predicted to be unaffected; one produced a normal healthy infant, the other miscarried shortly after CV sampling. 相似文献
72.
Bates MN Buckland SJ Garrett N Ellis H Needham LL Patterson DG Turner WE Russell DG 《Chemosphere》2004,54(10):1431-1443
Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and organochlorine pesticides were measured in the serum of a sample of the New Zealand population aged 15 years and older. This was the first study to obtain representative measures of PCDDs, PCDFs and PCBs in the adult population of an entire country. Serum samples were obtained in 1996-1997. Potentially occupationally exposed individuals were excluded. Serum samples were pooled according to stratification criteria for area of residence, ethnicity, age, and sex. Of the 80 possible strata, sufficient serum for chemical analysis was available for 60, to which 1,834 individual samples contributed. For the PCDDs and PCDFs, most 2,3,7,8-chlorinated congeners were measured in all strata, with a mean toxic equivalents concentration across all strata of 12.8 ng TEQ kg(-1) lipid. Seven PCB congeners were frequently measured, including the coplanar congeners #126 and #169, quantified in all strata. Of the pesticides and their metabolites, only beta-HCH, dieldrin and pp'-DDE were consistently detected across strata. There was a general trend of increasing concentration with age. There were no consistent differences between the sexes, or between people of Maori (the indigenous people of New Zealand) and non-Maori ethnicity. Concentrations of PCDDs and PCDFs tended to increase in a North-South direction, possibly reflecting greater levels of industrialization and population concentration, and concentrations of the pesticide products were highest in the South, possibly reflecting historical use patterns. Results were consistent with a recent study of concentrations of these compounds in the milk of first-time mothers. 相似文献
73.
Miles GP Samuel MA Zhang Y Ellis BE 《Environmental pollution (Barking, Essex : 1987)》2005,138(2):230-237
The recent increase in tropospheric ozone (O(3)) concentrations promotes additional oxidative stress through the production of reactive oxygen species (ROS) in plant tissues, resulting in the activation of genes whose products enable the stressed cells to retain their integrity and function. This response is made possible by an integration of highly regulated signaling networks that mediate the perception of, and response to, this oxidative assault. In Arabidopsis thaliana, ROS-induced signaling has been shown to flow through a protein phosphorylation cascade involving the mitogen-activated protein kinases (MAPKs) AtMPK3 (MPK3) and AtMPK6 (MPK6). We found that RNAi-mediated silencing of MPK6 renders the plant more sensitive to ozone, as determined by visible leaf damage. The MPK6-RNAi genotype also displayed a more intense and prolonged activation of MPK3 compared to that of WT plants. An MPK3 loss-of-function genotype is similarly very sensitive to ozone, and displays an abnormally prolonged MPK6 activation profile, suggesting reciprocity in regulation between these two MAPKs. 相似文献
74.
Faced with the task of treating significant volumes of complex industrial wastewaters, the biological components of municipal wastewater treatment plants are operating under the risk of toxic or inhibitory contaminants from the industrial effluents that may be detrimental to their operation. This might lead to undesirable effluent toxicity and/or result in permit violations. Therefore, there is a need for upset early warning systems that can protect full-scale plants from toxic or inhibitory constituents in the incoming wastewaters. This study focused on the development of a protocol for rapid detection of potentially toxic inhibitory or toxic wastewaters using combined aerobic respirometric and anaerobic batch techniques. Aerobic respirometers equipped with automated data acquisition systems were used as potential early warning devices. The inhibition effect on carbon and nitrogen oxidation was assessed. The degree of inhibition was evaluated as the concentration causing 50% reduction in microbial activity, which was estimated by an inhibition model. Anaerobic toxicity assays were also conducted to evaluate the inhibitory effects of the toxic compounds to anaerobic inocula obtained from a master culture reactor fed with ethanol. The developed protocol for early detection of toxicity was validated using wastewater samples from a biotechnology industry and a food processing industry, and pure chemicals such as furfural and phenol. Varying degrees of sensitivity were observed in the study when different groups of microorganisms, wastewater samples, and chemicals were tested. The comparison of aerobic and anaerobic inhibition suggested the importance of using both aerobic and anaerobic cultures to maximize the necessary sensitivity of the protocol. 相似文献
75.
In 1997, the U.S. Environmental Protection Agency revised the National Ambient Air Quality Standard governing ozone (O3), adding an 8-hr standard of 0.08 ppm and phasing out the 1-hr requirement of 0.12 ppm. The 8-hr standard is intended to provide greater protection for human health. This research examines spatial and temporal patterns of exceedances of the standards using monitoring data and modeled estimates. The Penn State/National Center for Atmospheric Research Mesoscale Model and Models-3 framework were used to estimate hourly O3 concentrations for 4-km resolution in the Maryland/Virginia/Delaware/Washington, DC, and northern Georgia domains. Results reveal that the spatial and temporal nature of compliance is considerably different under the 8-hr standard. In the modeling simulations, the 8-hr standard was exceeded 2-5.2 times more often and in a 1.8-16.2 times larger area than the 1-hr standard. The 8-hr standard was exceeded in areas that generally comply with the 1-hr standard and are not well covered by the monitoring network. These results imply that a larger population resides in areas with unhealthy O3 levels than noncompliance with the original 1-hr standard suggests. For the MD/VA/DE/DC domains, 80 and 98% of the total population live in areas with 8-hr National Ambient Air Quality Standards (NAAQS) exceedances for the 1990 and 1995 episodes, respectively. 相似文献
76.
77.
Four endosymbiotic diatoms were isolated from 2 species of larger foraminifera collected in the Red Sea and Hawaii. The photoadaptive responses of the cultured diatoms were measured at 312, 19 and 7 W cm-2. Two of the diatoms (Fragilaria shiloi and Nitzschia laevis), both isolated from Amphistegina lessonii, grew fastest at 312 W cm-2. The other two diatoms (N. valdestriata and N. panduriformis) which were isolated from Heterostegina depressa, grew best at 19 W cm-2. Of the four diatoms, F. shiloi grew best at high light levels. Also in F. shiloi, chlorophyll c content per cell was directly proportional to light intensity; in contrast chlorophyll a and carotenoids increased to maxima at 19 W cm-2. The chlorophyll a and c and carotenoid content of N. valdestriata were also maximal at 19 W cm-2. Photosynthetic rates, measured by respirometry, suggested that the diatoms were photoinhibited at higher light intensities and did well at moderately low light intensities (175W cm-2). The photocompensation points of all 4 diatoms were about 2% of the light available in the spring at 1-m depth at Elat on the Red Sea. At Elat the photocompensation point would lie between 40 and 50 m if the algae were free in nature. The amount of attenuation of light by the shells of the host has not yet been measured. Presumably photocompensation of the algae within hosts is reached at depths less than 40 m. 相似文献
78.
William A. H. Ellis Alistair Melzer Fred B. Bercovitch 《Behavioral ecology and sociobiology》2009,63(8):1181-1188
Animal movement patterns and use of space depend upon food and nonfood resources, as well as conspecific and heterospecific
interactions, but models of habitat use often neglect to examine multiple factors and rarely include marsupials. We studied
habitat use in an Australian population of koalas (Phascolarctos cinereus) over a 6-year period in order to determine how koalas navigate their environment and partition limited patchy food and nonfood
resources. Tree selection among koalas appears to be mediated by folar chemistry, but nonfood tree selection exerts a major
impact on home range use due to thermoregulatory constraints. Koalas moved on a daily basis, during both day and night, but
daytime resting site was not necessarily in the same location as nighttime feeding site. Koalas had substantial home range
overlap in the near absence of resource sharing with less than 1% of trees located in areas of overlap used by multiple koalas.
We suggest that koala spatiotemporal distribution and habitat use are probably based upon a community structure of individuals,
with a checkerboard model best describing overlap in home range area but not in resource use. Nonfood refugia and social networks
should be incorporated into models of animal range and habitat use. 相似文献
79.
SUMMARY The generation, handling, and safe disposal of waste materials has become a major concern in North America. Approval of facilities for waste processing and proper disposal is becoming more difficult to obtain. Furthermore, there is a growing public awareness of the importance of conserving and preserving our valuable natural resources. This expanding awareness has given rise to the trend towards recycling or reuse of awide variety of solid wastes. Experiences with using waste materials in highway construction can vary considerably, depending on material characteristics, construction processes, and climatic differences. A number of waste materials may be suitable for use in highway construction, but others may not. The objective of this paper is introduced in two tasks. The first is to include a survey of the waste materials and by-products that have been used successfully, or may be used, as materials for highway construction or maintenance work. This also includes determination of the state of practice concerning economic and technical factors for these wastes. The second is to rank these materials based on three criteria: number of uses by State agencies, economic uses and performance aspects. 相似文献
80.
Ellis F. Darley 《Journal of the Air & Waste Management Association (1995)》2013,63(3):145-156
Most of the recent work on the effects of cement-kiln dust has been confined to Germany and results differ considerably. There appears to be little doubt that naturally deposited dust from certain cement plants is responsible for leaf injury to deciduous and coniferous species and occasionally for death of the latter. Injury results from the combination of a relatively thick crust deposit and the toxicity of alkaline solutions formed when dusts are deposited in the presence of free moisture. The results of several hand-dusted field experiments, however, are not so conclusive; dusts are reported as either harmful, harmless, or even indirectly beneficial. In the present laboratory investigation, the comparison of CO2 exchange in the leaf between dusted and nondusted leaves, as well as occurrence of obvious tissue damage, were used as the criteria of dust effects in short term experiments. The results demonstrated that the finer particles of certain cement-kiln dusts collected from electrostatic precipitators do interfere with CO2 exchange and in some cases cause considerable leaf injury. The results further suggest that calcium content alone may not be the only indicator of whether a dust might be injurious, and that much more needs to be known about the effects of the interaction of chemical composition, particle size, and deposition rate. 相似文献