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561.
Kenneth Möllersten Lin Gao Jinyue Yan 《Mitigation and Adaptation Strategies for Global Change》2006,11(5-6):1129-1150
This paper investigates overall CO2 balances of combined heat and power (CHP) plants with CO2 capture and storage (CCS) in Kraft pulp and paper mills. The CHP plants use biomass-based fuels and feature advanced gasification and combined cycle technology. Results from simple process simulations of the considered CHP plants are presented. Based on those results and taking into account the major direct and indirect changes in CO2 emissions, the study shows that implementing CCS leads to steep emission reductions. Furthermore, a preliminary cost assessment is carried out to analyse the CO2 mitigation cost and its dependence on the distance that the CO2 must be transported to injection sites. 相似文献
562.
563.
Wendy Bailey Gary R. Freidenberg Hector E. James John R. Hesselink Kenneth Lee Jones MD 《黑龙江环境通报》1990,10(10):623-629
We report an infant with a craniopharyngioma which was detected in utero. Maternal uterine ultrasonography, done at 27 weeks because of polyhydramnios, revealed a 4 cm midline mass near the base of the fetal skull. At 31 weeks, magnetic resonance imaging of the maternal abdomen confirmed the presence of a mass in the region of the third ventricle and revealed hydrocephalus. Two days post-partum a computed tomography (CT)-guided needle biopsy of the mass was performed and recovered tissue which was histologically consistent with a craniopharyngioma. The infant' s postnatal period was complicated by seizures, which were treated with phenobarbital, and by progressive hydrocephalus, necessitating placement of a ventriculo-peritoneal shunt. He also received therapy for central hypothyroidism and diabetes insipidus. The infant' s parents refused permission for attempted resection of the tumour and he died at 8 weeks of age. This represents the second reported case of an antenatally detected craniopharyngioma. Four other cases of different intracranial tumours have been detected in utero using ultrasound, with no reported survivors past 3 days of age. There is a uniformly poor prognosis of such infants, but earlier diagnosis and intervention may change this result. 相似文献
564.
Stefan Grönkvist Kenneth Möllersten Kim Pingoud 《Mitigation and Adaptation Strategies for Global Change》2006,11(5-6):1083-1096
Carbon dioxide capture and permanent storage (CCS) is one of the most frequently discussed technologies with the potential to mitigate climate change. The natural target for CCS has been the carbon dioxide (CO2) emissions from fossil energy sources. However, CCS has also been suggested in combination with biomass during recent years. Given that the impact on the earth's radiative balance is the same whether CO2 emissions of a fossil or a biomass origin are captured and stored away from the atmosphere, we argue that an equal reward should be given for the CCS, independent of the origin of the CO2. The guidelines that provide assistance for the national greenhouse gas (GHG) accounting under the Kyoto Protocol have not considered CCS from biomass (biotic CCS) and it appears that it is not possible to receive emission credits for biotic CCS under the first commitment period of the Kyoto Protocol, i.e., 2008–2012. We argue that it would be unwise to exclude this GHG mitigation alternative from the competition with other GHG mitigation options. We also propose a feasible approach as to how emission credits for biotic CCS could be included within a future accounting framework. 相似文献
565.
Oil-Mineral Aggregate Formation on Oiled Beaches: Natural Attenuation and Sediment Relocation 总被引:1,自引:0,他引:1
Kenneth Lee Patricia Stoffyn-Egli Edward H Owens Gary A Sergy Chantal C Guénette Roger C Prince 《Spill Science & Technology Bulletin》2003,8(3):285-296
The significance of oil-mineral aggregate (OMA) formation on the effectiveness of the in situ shoreline treatment options of natural attenuation (natural recovery) and sediment relocation (surf washing) was examined during field trials on two mixed-sediment (sand and pebble) beaches experimentally oiled with IF-30 oil. At both sites, the amount of oil remaining in the experimental plots was dramatically reduced within five days after sediment relocation treatments. Time-series microscopy and image analysis of breaker-zone water samples demonstrate that OMA formation occurred naturally on the oiled beaches at both sites and was accelerated by the sediment relocation procedure. Lower concentrations of OMA in the breaker zone at Site 3 are attributed to the higher wave-energy levels at this site that presumably facilitated more rapid OMA dispersion. The granulometry and mineralogy of beach sediment and of subtidal sediment trap samples indicate that the material settling in nearshore waters originated from the relocated sediment and that a portion of the finer sediment was probably transported out of the study region before settling. Gas chromatography/mass spectrometry analysis demonstrated that a significant fraction of the oil dispersed into nearshore waters and sediments by interaction with mineral fines was biodegraded. The fact that little or no residual oil was found stranded on the shore in areas adjacent to the experimental plots and that only small amounts of oil were found in nearshore subtidal sediments and sediment trap samples suggests that a large fraction of the oil lost from the experimental plots may have been dispersed in the form of relatively buoyant OMA. 相似文献
566.
INTRODUCTION: The purpose of this investigation was to identify risky driving behaviors and dispositions that distinguish drivers who use a cell phone while operating a motor vehicle from non-cell phone using drivers. METHOD: Annual telephone surveys were used to identify drivers who reported using a cell phone while driving in the last month (n=1803) and were compared to those who said they did not use cell phones while driving (n=1578). RESULTS: Cell phone using drivers were more likely to report driving while drowsy, going 20 mph over the speed limit, driving aggressively, running a stop sign or red light, and driving after having had several drinks. They were also more likely to have had a prior history of citation and crash involvement than non-cell phone using drivers. Cell phone using drivers also reported they were less careful and more in a hurry when they drive than non-cell phone using drivers. CONCLUSION: Cell phone using drivers report engaging in many behaviors that place them at risk for a traffic crash, independent of the specific driving impairments that cell phone usage may produce. Strategies that combine coordinated and sustained enforcement activities along with widespread public awareness campaigns hold promise as effective countermeasures for these drivers, who resemble aggressive drivers in many respects. 相似文献
567.
OBJECTIVE: Impaired drivers and other high-risk road users are less likely to use their safety belts, thus increasing the risk of fatal injury in the event of a crash. Although safety belt laws have been shown to increase wearing rates for daytime non-crash-involved drivers and their front-seat passengers, little evidence is available on the effect these laws have on belt usage by crash-involved drinking drivers and their passengers. METHODS: This study evaluated the influence of primary safety belt law upgrades from secondary laws on front-seat occupants of passenger cars driven by drinking drivers in fatal crashes in five states: California, Illinois, Maryland, Michigan, and Washington. The outcome measures used to evaluate these law upgrades were (1) the change in safety belt usage rates of front-seat occupants in passenger cars driven by drinking drivers in fatal crashes and (2) the change in alcohol-related front-seat occupant fatalities in passenger cars driven by drinking drivers. RESULTS: Four of the five states demonstrated increases in safety belt use by front-seat occupants of passenger cars of drinking drivers in fatal crashes following the upgrade to primary safety belt laws. Three states (California, Michigan, and Washington) experienced significant reductions in the number of front-seat occupant fatalities in vehicles driven by drinking drivers. CONCLUSIONS: The adoption of primary law upgrades was associated with significant increases in safety belt use (four of five states) and significant reductions in fatalities among high-risk occupants (i.e., front-seat occupants involved in fatal crashes in vehicles driven by drinking drivers) in three of the five states studied. 相似文献
568.
Hanneke J. M. Meijer Arike Gill Perry G. B. de Louw Lars W. Van Den Hoek Ostende Julian P. Hume Kenneth F. Rijsdijk 《Die Naturwissenschaften》2012,99(3):177-184
Since 2005, excavations at Mare aux Songes, Mauritius, have revealed the presence of a very rich, ∼4,200-year-old fossil bone
bed including dodo (Raphus cucullatus) bones and bone fragments. The recently excavated dodo assemblage comprises at least 17 individuals and is characterised
by the presence of small and fragile skeletal elements, a dominance of leg elements and an absence of juveniles. The hydrology
of the area suggests that dodos, like many other species, were probably lured to Mare aux Songes by the presence of freshwater
during times of drought. The most likely scenario for the origin of the fossil deposit is that animals became trapped in the
sediment in repeated miring events, which would favour the conservation of hindlimbs. Such a scenario is fully in accordance
with the taphonomic characteristics of the bone assemblage. 相似文献
569.
Fossils from the central Transantarctic Mountains in Antarctica are referred to a new species of the Triassic genus Kombuisia, one of four dicynodont lineages known to survive the end-Permian mass extinction. The specimens show a unique combination
of characters only present in this genus, but the new species can be distinguished from the type species of the genus, Kombuisia frerensis, by the presence of a reduced but slit-like pineal foramen and the lack of contact between the postorbitals. Although incomplete,
the Antarctic specimens are significant because Kombuisia was previously known only from the South African Karoo Basin and the new specimens extend the taxon’s biogeographic range
to a wider portion of southern Pangaea. In addition, the new finds extend the known stratigraphic range of Kombuisia from the Middle Triassic subzone B of the Cynognathus Assemblage Zone into rocks that are equivalent in age to the Lower Triassic Lystrosaurus Assemblage Zone, shortening the proposed ghost lineage of this taxon. Most importantly, the occurrence of Kombuisia and Lystrosaurus mccaigi in the Lower Triassic of Antarctica suggests that this area served as a refuge from some of the effects of the end-Permian
extinction. The composition of the lower Fremouw Formation fauna implies a community structure similar to that of the ecologically
anomalous Lystrosaurus Assemblage Zone of South Africa, providing additional evidence for widespread ecological disturbance in the extinction’s
aftermath. 相似文献
570.
John P. Kent Kenneth J. Murphy Finian J. Bannon Niamh M. Hynes Thomas J. Hayden 《Die Naturwissenschaften》2009,96(7):763-770
Testosterone (T) concentrations in many species are sensitive to seasonal changes and to changes in social conditions. However,
the effect of the natural or endogenous T increase in the juvenile on their social behaviour is not well understood. In this
study, T and behaviour were measured from the pro-social juvenile to the adult stage in semi-feral domestic fowl. During the
pro-social phase T levels and the distance chicks maintained between each other, i.e. inter-individual distance (IID) were
low. Then, as T increased, a corresponding increase in IID occurred and continued in males until dispersal to individual adult
male territories. In the new and initially stable adult social structure, T declined and IID remained high, indicating a new
behavioural mechanism was in place. Males first mated as T levels were declining. They were then challenged; then T increased,
and then IID increased again. Adult male T levels fluctuate, being low or declining in a socially stable environment and increasing
following a challenge, suggesting a regulatory or modulating role for T. The results are consistent with T having an endogenous
role: in the juvenile, driving behavioural change towards adulthood, and in adulthood, a modulating role regulating social
organisation. 相似文献