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61.
Summary The social organization of the pipistrelle bat (Pipistrellus pipistrellus) was studied by means of bat boxes in southern Sweden. The males set up territories around a roosting site in the beginning of the summer at the same time as the females formed nursing colonies. After breeding, the females joined the single males in their day roosts establishing transient mating harems. Subsequently, immatures arrived at the mating grounds. The immature females, which probably attained sexual maturity during their first autumn, were admitted to the day roosts of the harem males, in contrast to the immature males. The size of the harem was dependent on the total number of females present on the mating grounds. The size, however, was also restricted by some factor, presumably the quantity of food resources in the surroundings of the specific roost site, or the capability of the harem male for mating. The mating system in the pipistrelle bat is best characterized as a resource defence polygyny. Available data on other related temperate species indicate a similar social organization in Pipistrellus nathusii and Nyctalus noctula. 相似文献
62.
Höhener P Duwig C Pasteris G Kaufmann K Dakhel N Harms H 《Journal of contaminant hydrology》2003,66(1-2):93-115
Predictions of natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone rely critically on information about microbial biodegradation kinetics. This study aims at determining kinetic rate laws for the aerobic biodegradation of a mixture of 12 volatile petroleum hydrocarbons and methyl tert-butyl ether (MTBE) in unsaturated alluvial sand. Laboratory column and batch experiments were performed at room temperature under aerobic conditions, and a reactive transport model for VOC vapors in soil gas coupled to Monod-type degradation kinetics was used for data interpretation. In the column experiment, an acclimatization of 23 days took place before steady-state diffusive vapor transport through the horizontal column was achieved. Monod kinetic parameters Ks and vmax could be derived from the concentration profiles of toluene, m-xylene, n-octane, and n-hexane, because substrate saturation was approached with these compounds under the experimental conditions. The removal of cyclic alkanes, isooctane, and 1,2,4-trimethylbenzene followed first-order kinetics over the whole concentration range applied. MTBE, n-pentane, and chlorofluorocarbons (CFCs) were not visibly degraded. Batch experiments suggested first-order disappearance rate laws for all VOCs except n-octane, which decreased following zero-order kinetics in live batch experiments. For many compounds including MTBE, disappearance rates in abiotic batch experiments were as high as in live batches indicating sorption. It was concluded that the column approach is preferable for determining biodegradation rate parameters to be used in risk assessment models. 相似文献
63.
64.
太湖典型河网区地表水与沉积物氮、磷和重金属含量空间分异 总被引:2,自引:0,他引:2
将无锡城乡交错区河网分为城镇生活区水巷、工业区主河道、农业区主河道、农业区支流和鱼塘5种类型区.通过秋季(旱季)和夏季(雨季)2次采样,研究氮、磷和Cu、Zn、Pb、Cr、Cd在地表水和沉积物中的含量及其空间变化.结果表明:(1)城乡交错区地表水氮、磷来源于生活污染和工业污染的比例大于农田,同时具有来源分散、污染面广的特征.(2)由于城镇地表径流和工业活动影响,各类型区地表水重金属含量均有不同程度提高.但地表水重金属主要沿主河道迁移,旱季和雨季主河道重金属含量均大于农业区支流,而且随着与城镇距离增加,主河道沉积物重金属含量迅速降低,重金属污染影响范围较小.(3)与重金属相比,地表水氮、磷污染仍是太湖水网区主要的环境问题.但城镇及其周围河流沉积物中富集的重金属含量很高,其潜在环境风险不容忽视. 相似文献
65.
Ton Snelder Anthony Lehmann Nicolas Lamouroux John Leathwick Karin Allenbach 《Environmental management》2010,45(5):939-952
Ecological regionalizations define geographic regions exhibiting relative homogeneity in ecological (i.e., environmental and
biotic) characteristics. Multivariate clustering methods have been used to define ecological regions based on subjectively
chosen environmental variables. We developed and tested three procedures for defining ecological regions based on spatial
modeling of a multivariate target pattern that is represented by compositional dissimilarities between locations (e.g., taxonomic
dissimilarities). The procedures use a “training dataset” representing the target pattern and models this as a function of
environmental variables. The model is then extrapolated to the entire domain of interest. Environmental data for our analysis
were drawn from a 400 m grid covering all of Switzerland and consisted of 12 variables describing climate, topography and
lithology. Our target patterns comprised land cover composition of each grid cell that was derived from interpretation of
aerial photographs. For Regionalization 1 we used conventional cluster analysis of the environmental variables to define 60
hierarchically organized levels comprising from 5 to 300 regions. Regionalization 1 provided a base-case for comparison with
the model-based regionalizations. Regionalization 2, 3 and 4 also comprised 60 hierarchically organized levels and were derived
by modeling land cover composition for 4000 randomly selected “training” cells. Regionalization 2 was based on cluster analysis
of environmental variables that were transformed based on a Generalized Dissimilarity Model (GDM). Regionalization 3 and 4
were defined by clustering the training cells based on their land cover composition followed by predictive modeling of the
distribution of the land cover clusters using Classification and Regression Tree (CART) and Random Forest (RF) models. Independent
test data (i.e. not used to train the models) were used to test the discrimination of land cover composition at all hierarchical
levels of the regionalizations using the classification strength (CS) statistic.
CS for all the model-based regionalizations was significantly higher than for Regionalization 1. Regionalization 3 and 4 performed
significantly better than Regionalization 2 at finer hierarchical levels (many regions) and Regionalization 4 performed significantly
better than Regionalization 3 for coarse levels of detail (few regions). Compositional modeling can significantly increase
the performance of numerically defined ecological regionalizations. CART and RF-based models appear to produce stronger regionalizations
because discriminating variables are able to change at each hierarchic level. 相似文献
66.
Chantal Deden Kornelia Neveling Dimitra Zafeiropopoulou Christian Gilissen Rolph Pfundt Tuula Rinne Nicole de Leeuw Brigitte Faas Thatjana Gardeitchik Suzanne C. E. H. Sallevelt Aimee Paulussen Servi J. C. Stevens Esther Sikkel Mariet W. Elting Merel C. van Maarle Karin E. M. Diderich Nicole Corsten-Janssen Klaske D. Lichtenbelt Guus Lachmeijer Lisenka E. L. M. Vissers Helger G. Yntema Marcel Nelen Ilse Feenstra Wendy A. G. van Zelst-Stams 《黑龙江环境通报》2020,40(8):972-983
Objective
The purpose of this study was to explore the diagnostic yield and clinical utility of trio-based rapid whole exome sequencing (rWES) in pregnancies of fetuses with a wide range of congenital anomalies detected by ultrasound imaging.Methods
In this observational study, we analyzed the first 54 cases referred to our laboratory for prenatal rWES to support clinical decision making, after the sonographic detection of fetal congenital anomalies. The most common identified congenital anomalies were skeletal dysplasia (n = 20), multiple major fetal congenital anomalies (n = 17) and intracerebral structural anomalies (n = 7).Results
A conclusive diagnosis was identified in 18 of the 54 cases (33%). Pathogenic variants were detected most often in fetuses with skeletal dysplasia (n = 11) followed by fetuses with multiple major fetal congenital anomalies (n = 4) and intracerebral structural anomalies (n = 3). A survey, completed by the physicians for 37 of 54 cases, indicated that the rWES results impacted clinical decision making in 68% of cases.Conclusions
These results suggest that rWES improves prenatal diagnosis of fetuses with congenital anomalies, and has an important impact on prenatal and peripartum parental and clinical decision making. 相似文献67.
Maurike de Groot-van der Mooren Gert de Graaf Michel E Weijerman Mariette J. V Hoffer Jeroen Knijnenburg Anne-Marie M. F van der Kevie-Kersemaekers Angelique J. A Kooper Els Voorhoeve Birgit Sikkema-Raddatz Laura J. C. M van Zutven Malgorzata Ilona Srebniak Karin Huijsdens-van Amsterdam John J. M Engelen Dominique Smeets Anton H van Kaam Martina C Cornel 《黑龙江环境通报》2021,41(10):1351-1359
68.
Wahyudiono Mitsuru Sasaki Motonobu Goto 《Journal of Material Cycles and Waste Management》2011,13(1):68-79
The conversion of biomass waste into resources as a recycling process is receiving increased interest due to the perceived
need for a sustainable global carbon cycle and environmental considerations. Several treatment processes are being developed.
Hydrothermal treatment is one of the most effective approaches, because water at high temperatures and high pressures behaves
as a reaction medium with remarkable properties. In this work, the reaction behavior of guaiacol as a biomass model compound
was studied in subcritical water at 483–563 K and in supercritical water at 653–673 K using a batch reactor. Guaiacol can
be considered representative of the aromatic ring structures present in lignin, a major component of woody biomass. The chemical
species formed in aqueous products were identified by gas chromatography/mass spectrometry and quantified using high-performance
liquid chromatography. The effect of pressure and reaction time on the conversion process of guaiacol is discussed. The results
obtained indicate that this method has potential for efficient organic waste conversion. 相似文献
69.
An Alternative Approach to Photochemical Ozone Creation Potentials Applied under European Conditions
Johanna Altenstedt Karin Pleijel 《Journal of the Air & Waste Management Association (1995)》2013,63(6):1023-1036
ABSTRACT Photochemical ozone creation potential (POCP) values for 83 different volatile organic compounds (VOCs), including CO and CH4, were calculated under different environmental conditions representative for Europe. These calculations show that variations in POCP values are large between different types of chemical environments and that POCP values for VOCs should be presented as ranges instead of single values. POCP ranges are based on the extremes of the POCP values and are defined with the intention to include all POCP values an individual VOC will obtain in any European environment where O3 formation is of environmental concern. The POCP ranges indicate large differences in O3 production between individual VOCs, which justifies the use of this ranking scale instead of treating all VOCs as a homogeneous group of species in abatement strategies. Both the average O3 production over 96 hr and the maximum contribution to the O3 concentration were studied. The most efficient O3 producers were found to be iso-prene, 2-methyl-2-butene, and acrolein. As a group, the alkenes are the most potent O3 producers, followed by higher alkanes and then the aromatics. The calculated values show a good agreement with previously calculated POCP values under northern European conditions. 相似文献
70.
Karin Ireton 《生态毒理学报》1999,21(2)
采取少数几个小的志愿步骤 南非的志愿举措大部分是由于公司经营所在的不确定法规环境的结果.环境立法的确存在,但过去执法不力,这部分地由于工业界和政府都认为增长和就业机会是与环境管理相冲突的,而且前者优于后者.希望随着可持续发展的信息得到更好的理解,那些冲突类别将成为过去的事情. 相似文献