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101.
The recycling of rubber from old tyres by batch hydrogenation has been performed using tubing bomb reactors. Important process variables like temperature, reaction time, initial hydrogen pressure and nature of gas used have been studied. In all the runs the maximum total conversion was achieved. Conversion products are comprised of oils and gases, being the asphaltene yield lower than 1% in all conditions tested. The most valuable conversion products, oils, have been systematically analysed by TLC-FID1 and the influence of the process variables in oils composition has been assessed. From the obtained results, it can be deduced that the conversion of rubber in oils is a fast thermal process, which is neither affected by initial pressure nor the nature of gas used. But on the other hand, the nature of obtained oils and gases is a function of process variables. 相似文献
102.
Raquel Garcia Rodriguez Loida Garcia Cruz Yeray Novoa Medina Raquel Garcia Delgado Julio Perez Gonzalez Carmen Palma Milla Juan Lopez Siles Margarita Medina Castellano Jose Angel Garcia Hernandez Alfredo Santana Rodriguez 《黑龙江环境通报》2019,39(6):415-419
Solitary median maxillary central incisor (SMMCI) syndrome is a complex disorder consisting of multiple, developmental defects involving midline structures of the head, which includes the cranial bones, the maxilla, and its container dentition (specifically the central incisor tooth germ), together with other midline structures of the body. SMMCI may appear as an isolated trait or in association with other midline developmental anomalies. We describe the case of a patient with SMMCI. He presented with a solitary median maxillary incisor, short stature, corpus callosum anomalies and a microform of holoprosencephaly (HPE), diabetes insipidus, and neurodevelopmental delay. The diagnosis was performed postnatally based on clinical features, radiological imaging, and a comprehensive genetic study. SMMCI can be diagnosed during the prenatal or neonatal periods or during infancy. Evaluation of the superior maxillary bone is important for prenatal diagnosis. Direct evaluation through bidimensional ultrasound or the use of multiplanar ultrasound or tridimensional reconstruction should be performed in cases of brain or face malformations. Early diagnosis can contribute to improved prenatal assessment and postnatal management. 相似文献
103.
H.A. Carreras J.H. Rodriguez C.M. González E.D. Wannaz F. Garcia Ferreyra C.A. Perez M.L. Pignata 《Atmospheric environment (Oxford, England : 1994)》2009,43(18):2944-2949
Samples of the vascular plant Tradescantia pallida and the lichen Usnea amblyoclada were exposed from October 2004 to April 2005 in three sites with different local sources of air pollution in Córdoba city, Argentina. Simultaneous determinations of the ambient levels of total suspended particles were made for each site. Young inflorescenses of T. pallida were collected in November, February and April and the frequency of micronuclei was determined on early tetrads of pollen mother cells. Physiological parameters and the elemental composition of lichen thalli were measured from samples exposed and replaced every month. Significant differences among sampling sites were observed in the frequency of micronuclei measured in T. pallida as well as in many physiological parameters and elements accumulated in lichen thalli. The mass of particulate material as well as the concentration of Ca, Mn, Cu, Zn and Sr was significantly different in different sampling sites, too. These results suggest that in situ biomonitoring using both higher plants and lichens may be of use to characterize air pollution in areas devoid of instrumental monitoring techniques or where it is necessary to explore the distribution of air contaminants at a microscale. 相似文献
104.
Alexandro M.M. Vargas André L. Cazetta Clarice A. Garcia Juliana C.G. Moraes Eurica M. Nogami Ervim Lenzi Willian F. Costa Vitor C. Almeida 《Journal of environmental management》2011
Activated carbons were prepared from flamboyant pods by NaOH activation at three different NaOH:char ratios: 1:1 (AC-1), 2:1 (AC-2), and 3:1 (AC-3). The properties of these carbons, including BET surface area, pore volume, pore size distribution, and pore diameter, were characterized from N2 adsorption isotherms. The activated carbons obtained were essentially microporous and had BET surface area ranging from 303 to 2463 m2 g−1.13C (CP/MAS and MAS) solid-state NMR shows that the lignocellulosic structures were completely transformed into a polycyclic material after activation process, thermogravimetry shows a high thermal resistance, Boehm titration and Fourier-transform infrared spectroscopy allowed characterizing the presence of functional groups on the surface of activated carbons. Scanning electron microscopy images showed a high pore development. The experimental results indicated the potential use of flamboyant pods as a precursor material in the preparation of activated carbon. 相似文献
105.
Tonucci RG Nair PK Nair VD Garcia R Bernardino FS 《Journal of environmental quality》2011,40(3):833-841
Silvopastoral management of fast-growing tree plantations is becoming popular in the Brazilian Cerrado (savanna). To understand the influence of such systems on soil carbon (C) storage, we studied C content in three aggregate size classes in six land-use systems (LUS) on Oxisols in Minas Gerais, Brazil. The systems were a native forest, a treeless pasture, 24- and 4-yr-old eucalyptus ( sp.) plantations, and 15- and 4-yr-old silvopastures of fodder grass plus animals under eucalyptus. From each system, replicated soil samples were collected from four depths (0-10, 10-20, 20-50, and 50-100 cm), fractionated into 2000- to 250-, 250- to 53-, and <53-μm size classes representing macroaggregates, microaggregates, and silt + clay, respectively, and their C contents determined. Macroaggregate was the predominant size fraction under all LUS, especially in the surface soil layers of tree-based systems. In general, C concentrations (g kg soil) in the different aggregate size fractions did not vary within the same depth. The soil organic carbon (SOC) stock (Mg C ha) to 1-m depth was highest under pasture compared with other LUS owing to its higher soil bulk density. The soils under all LUS had higher C stock compared with other reported values for managed tropical ecosystems: down to 1 m, total SOC stock values ranged from 461 Mg ha under pasture to 393 Mg ha under old eucalyptus. Considering the possibility for formation and retention of microaggregates within macroggregates in low management-intensive systems such as silvopasture, the macroaggregate dynamics in the soil seem to be a good indicator of its C storage potential. 相似文献
106.
In this paper a PSIAC-based multi-parameter fuzzy pattern recognition (MPFPR) model is proposed and applied for classifying and ranking the potential soil erosion (PSE). In this approach, standard value matrix is used to define the membership degrees of each catchment to each class and the feature values are used for alternative ranking. The characteristic of PSE for each class is expressed by linguistic variables. The proposed method is straightforward, easy to understand, very practical, and its results may easily be interpreted. To assess the performance of the model, the results of PSIAC MPFPR and original PSIAC method are interpreted and compared with the observed data. It is shown that the proposed approach reflects the fuzzy nature of the soil erosion more efficiently and is quite robust for application in real world cases. 相似文献
107.
Total mercury (Hg(T)) and bioavailability Hg (Hg(HCl)) concentrations in soil were determined in five districts in Wuhu urban area. Spatial pattern of soil Hg concentration was generated through kriging technology. Results showed that Hg concentration in soil ranged from 0.024 to 2.844 mg kg(?-1) with an average of 0.207 mg kg(?-1). Hg concentration in soil appeared to have a block distribution and decreased from downtown to surrounding district. And Hg concentrations appeared to have a medium scale spatial auto correlation, strongly affected by human activity. The maximal Hg average concentration (0.332 mg kg(?-1)) in soil appeared in Jinghu district, where the high intensity of human activities is. Second highest Hg average concentration (0.263 mg kg(?-1)) in soil appeared in development district, where the intensive industrial activities are. Bioavailability Hg concentration in soil ranged from 2.6 to 4.9 μg kg(?-1) with an average of 3.8 μg kg(?-1), which had a ratio of 0.28~6.44% to total Hg. The ratios of bioavailability Hg to total Hg in vegetable soil were bigger than those of park soil. Correlation analysis showed that total Hg, organic matter, total phosphorus, and bioavailability Hg concentrations in soil were significantly positively correlated. Hg concentration in vegetable ranged from 2.7 to 15.2 μg kg(?-1) with an average of 6.5 μg kg(?-1). Hg concentration in vegetable was positively correlated with Hg(HCl) concentration in soil. According to the calculation on hazard quotient (HQ) for children, inhalation of Hg vapor from soil is the main exposure pathway, in which HQ is 2.517 × 10(?-2), accounting for 80.3% of the four exposure pathways. Hazard index (HI) of the four exposure pathways is lower than the "safe" level of HI = 1; therefore, exposure of soil Hg exhibited little potential health risk to children in Wuhu urban area. 相似文献
108.
Prado Tatiana Barbosa Mikaela Renata Funada Araújo Ronalda Silva Garcia Suzi Cristina Melo Adalgisa Jesus Galvani Ana Tereza Brandão Carlos Jesus Silva Renan Lourenço Oliveira Sato Maria Inês Zanoli 《Food and environmental virology》2021,13(4):520-527
Food and Environmental Virology - Hepatitis A virus (HAV) is the major cause of enterically transmitted infectious hepatitis. Between 2016 and 2017, the number of confirmed cases of hepatitis A... 相似文献
109.
Dairy systems predominantly based on rotational grazing are notoriously hard to manage. In order to ensure profitability, this type of production requires quite good organisation, planning, and operating capability on the part of the farmer. A simulation-based decision support system, called SEPATOU, has been developed for this purpose. At the core of the decision support approach lies an explicit and rigorous modelling of the management strategy that underlies a dairy farmer's decision-making behaviour (real or hypothetical). The SEPATOU system is a discrete-event simulator that reproduces the day-to-day dynamics of the farmer's decision process and the response of the controlled biophysical system for which models of grass growth, animal consumption, and milk production are used. SEPATOU provides the means to evaluate and compare tentative strategies by simulating their application throughout the production season under different hypothetical weather conditions. The relative worth of a strategy can be assessed by analysing the effects on the biophysical system and their variability across the representative range of possible conditions that is considered. The activities to be managed concern the type and amount of conserved feed, where to fertilise and how much, the choice of fields to harvest, and most importantly, which field to graze next. Typically, SEPATOU is designed to be used by extension services and farming system scientists. It is implemented in C++ and is currently undergoing a validation process with the intended users. 相似文献
110.
Flavio Manoel Rodrigues da Silva Júnior Patrick Ferreira Silva Edariane Menestrino Garcia Roberta Daniele Klein Gianni Peraza-Cardoso Paulo Roberto Baisch Vera Maria Ferrão Vargas Ana Luíza Muccillo-Baisch 《Environmental geochemistry and health》2013,35(3):317-331
In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks. 相似文献