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81.
82.
83.
Although external sexually dimorphic traits are commonly found in males of combtooth blenny species, little is known about
the benefit they can convey to male mating success. Indeed, while female preferences for large males have been demonstrated
in some species, the possible role played by dimorphic ornaments has been neglected. We now report on the tentacled blenny,
Parablennius tentacularis, a species where males are characterized by bulb glands on the anal fin and both sexes exhibit a dark spot on the dorsal
fin and orbital tentacles. Males are territorial, make nests in empty bivalve shells, and provide solitary parental care for
the eggs. Using morphometric analysis and field collected data on male and female external features, nest characteristics
and number of eggs in the nests, we have assessed the development of dimorphic traits in both sexes and male mating success.
The results reveal that orbital tentacles of males are more developed and more variable in size than those of females. Larger
males exhibit longer orbital tentacles and larger anal glands but do not necessarily occupy larger nests. Male mating success
is significantly correlated with the inner nest surface area and with orbital tentacle size but not with body size. These
results provide support for a primary role of male ornaments in enhancing blenny male mating success and are discussed in
the context of mate choice for direct and indirect benefits. 相似文献
84.
The environmental occurrence of hexabromocyclododecane in Sweden 总被引:6,自引:0,他引:6
The brominated flame retardant hexabromocyclododecane (HBCD) is extensively used in Europe, but data on the environmental concentrations of this chemical are scarce. A first screening has been performed concerning the environmental occurrence of HBCD in Sweden, a country where the chemical is not produced and the current industrial use is very limited. Possible emission sources were identified through a systematic analysis of the use in a life cycle perspective. In addition to a few point sources, diffuse emissions from polymeric products are possible. Measurements have been performed close to certain possible point sources, in the urban environment and in remote regions, and included air, deposition, water, soil, sediments, sludge, biota and foodstuffs. HBCD was detected in all media analysed and in all environments. The relatively high concentrations detected in herring and foodstuffs provide evidence for bioaccumulation of HBCD. The presence of HBCD in remote background air implies that HBCD has potential for long-range atmospheric transport. There are also some indications that diffuse emissions of HBCD occur in the urban environment. 相似文献
85.
Hogrefe O Schwab JJ Drewnick F Lala GG Peters S Demerjian KL Rhoads K Felton HD Rattigan OV Husain L Dutkiewicz VA 《Journal of the Air & Waste Management Association (1995)》2004,54(9):1040-1060
Several collocated semicontinuous instruments measuring particulate matter with particle sizes < or =2.5 microm (PM2.5) sulfate (SO4(2-)) and nitrate (NO3-) were intercompared during two intensive field campaigns as part of the PM2.5 Technology Assessment and Characterization Study. The summer 2001 urban campaign in Queens, NY, and the summer 2002 rural campaign in upstate New York (Whiteface Mountain) hosted an operation of an Aerosol Mass Spectrometer, Ambient Particulate Sulfate and Nitrate Monitors, a Continuous Ambient Sulfate Monitor, and a Particle-Into-Liquid Sampler with Ion Chromatographs (PILS-IC). These instruments provided near real-time particulate SO4(2-) and NO3- mass concentration data, allowing the study of particulate SO4(2-)/NO3- diurnal patterns and detection of short-term events. Typical particulate SO4(2-) concentrations were comparable at both sites (ranging from 0 to 20 microg/m3), while ambient urban particulate NO3- concentrations ranged from 0 to 11 microg/m3 and rural NO3- concentration was typically less than 1 microg/m3. Results of the intercomparisons of the semicontinuous measurements are presented, as are results of the comparisons between the semicontinuous and time-integrated filter-based measurements. The comparisons at both sites, in most cases, indicated similar performance characteristics. In addition, charge balance calculations, based on major soluble ionic components of atmospheric aerosol from the PILS-IC and the filter measurements, indicated slightly acidic aerosol at both locations. 相似文献
86.
Evaluation of sequentially-coupled POP fluxes estimated from simultaneous measurements in multiple compartments of an air-water-sediment system 总被引:4,自引:0,他引:4
Palm A Cousins I Gustafsson O Axelman J Grunder K Broman D Brorström-Lundén E 《Environmental pollution (Barking, Essex : 1987)》2004,128(1-2):85-97
Bulk atmospheric deposition fluxes, air-water exchange fluxes, particle settling fluxes out of the upper water column, sediment trap fluxes in deep waters, and sediment burial fluxes of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) were simultaneously measured in the Koster Fjord, eastern Skagerak, on the Swedish west coast. The aim of the study was to compare the magnitude and direction of the compound fluxes in the system in order to diagnose key fate processes. The PCB and PAH fluxes via net atmospheric deposition, settling particles out of the surface and through deep waters, as well as into the accreting underlying sediments were shown to be remarkably similar, agreeing within a factor of a few for any given target compound. Fluxes of all PCB and PAH target compounds remained fairly constant with water column depth. Thus there was no evidence for net desorption from sinking particles. The net unidirectional and near balancing of vertical fluxes suggests a net transport of PCBs and PAHs from the atmosphere to the continental shelf sediments in the Koster Fjord, which is consistent with the hypothesis that the shelf sediments are important sinks for these compounds. 相似文献
87.
Photoinduced toxicity of fluoranthene on germination and early development of plant seedling 总被引:1,自引:0,他引:1
The influence of light on phytotoxicity of increased concentration (2, 5, 10 mg/l) of intact fluoranthene (FLT) and photomodified fluoranthene (phFLT) diluted in experimental solutions was investigated. The germination rate of lettuce (Lactuca sativa L.), onion (Allium cepa L.) and tomato (Lycopersicum esculentum L.) seeds and some parameters of seedlings primary growth of these plant species were used as laboratory indicators of phytotoxicity. Among them a length of root and shoot, their dry weight and a content of photosynthetic pigments in shoot were measured. The results demonstrated that the higher concentration (5 and 10 mg/l) of FLT and especially of phFLT significantly inhibited the germination rate of seeds and the length of root and shoot seedlings of all plant species. Decreased production of biomass expressed by dry weight of root and shoot was found in lettuce seedlings under the inhibitory effect of FLT and phFLT. An increased concentration of FLT and phFLT did not exhibit an unambiguous effect on the content of photosynthetic pigments in shoot of experimental plants. Only the highest concentration (10 mg/l) of FLT significantly increased content of chlorophylls a and b in lettuce, onion and tomato plants and content of carotenoids in lettuce and onion. Light intensified a significant inhibitory effect of phFLT in the most testified parameters of germination and seedling growth. 相似文献
88.
Stéphanie Rossignol Florian Couvidat Caroline Rio Sébastien Fable Guillaume Grignion Savelli Olivier Pailly Eva Leoz-Garziandi Jean-Francois Doussin Laura Chiappini 《环境科学学报(英文版)》2016,28(2):92-104
Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica(June 2011). Aimedat assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography–mass spectrometry(GC–MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls(C_3–C7),mono and di-carboxylic acids(C_3–C_18), and compounds bearing up to three functionalities.Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached. 相似文献
89.
Eva S. Stangler Stefan Jarau Michael Hrncir Ronaldo Zucchi Manfred Ayasse 《Chemoecology》2009,19(1):13-19
Foragers of several species of stingless bees deposit pheromone spots in the vegetation to guide recruited nestmates to a
rich food source. Recent studies have shown that Trigona and Scaptotrigona workers secrete these pheromones from their labial glands. An earlier report stated that species within the genus Geotrigona use citral from their mandibular glands for scent marking. Since convincing experimental proof for this conjecture is lacking,
we studied the glandular origin of the trail pheromone of Geotrigona mombuca. In field bioassays, newly recruited bees were diverted by artificial scent trails that branched off from the natural scent
trail deposited by their nestmates only when they were baited with extracts from the foragers’ labial glands. Compounds extracted
from the mandibular glands, however, did not release trail following behavior. This demonstrates that the trail pheromone
of G. mombuca is produced in the labial glands, as in Trigona and Scaptotrigona. Furthermore, in chemical analyses citral was identified exclusively in the foragers’ mandibular glands, which disproves
its supposed role as a trail pheromone. The labial glands contained a series of terpene- and wax type esters, with farnesyl
butanoate as major constituent. We, therefore, postulate that the trail pheromone of G. mombuca is composed of a blend of esters. 相似文献
90.
James C.Schwab 《生态毒理学报》2001,23(1):22-25
工业化国家和发展中国家的城市规划,都在变得越来越具有综合性,把城市生活的各种要素如经济发展、交通、娱乐和能源消费等等的环境功能结为一体 .多目标城市管理的目的是将政府在提高环境质量、社会公正和经济繁荣等方面所做的每一项努力而取得的积极成果能够最大限度地产生综合效应 .实现某一狭窄政策领域的一个目标而忽视决策的其它影响,从长远来看现在不再是可接受的,尽管曾经认为是好的规划 . 相似文献