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961.
Emerging evidence suggests the occurrence of comparative decision-making processes in mate choice, questioning the traditional idea of female choice based on rules of absolute preference. In such a scenario, females are expected to use a typical best-of-n sampling strategy, being able to recall previous sampled males based on memory of their quality and location. Accordingly, the quality of preferred mate is expected to be unrelated to both the number and the sequence of female visits. We found support for these predictions in the peacock blenny, Salaria pavo, a fish where females have the opportunity to evaluate the attractiveness of many males in a short time period and in a restricted spatial range. Indeed, even considering the variability in preference among females, most of them returned to previous sampled males for further evaluations; thus, the preferred male did not represent the last one in the sequence of visited males. Moreover, there was no relationship between the attractiveness of the preferred male and the number of further visits assigned to the other males. Our results suggest the occurrence of a best-of-n mate sampling strategy in the peacock blenny. 相似文献
962.
Julien Benoit Sandra C. Jasinoski Vincent Fernandez Fernando Abdala 《Die Naturwissenschaften》2017,104(7-8):66
The basal non-mammaliaform cynodonts from the late Permian (Lopingian) and Early Triassic are a major source of information for the understanding of the evolutionary origin of mammals. Detailed knowledge of their anatomy is critical for understanding the phylogenetic transition toward mammalness and the paleobiological reconstruction of mammalian precursors. Using micro-computed tomography (μCT), we describe the internal morphology of the interorbital region that includes the rarely fossilized orbitosphenoid elements in four basal cynodonts. These paired bones, which are positioned relatively dorsally in the skull, contribute to the wall of the anterior part of the braincase and form the floor for the olfactory lobes. Unlike procynosuchids and the more basal therapsids in which the orbitosphenoids are well developed, dense, and bear a ventral keel, the basal epicynodonts Cynosaurus, Galesaurus, and Thrinaxodon display cancellous, reduced, and loosely articulated orbitosphenoids, a condition shared with many eucynodonts. The hemi-cylindrical orbitosphenoid from which the mammalian condition is derived re-evolved convergently in traversodontid and some probainognathian cynodonts. 相似文献
963.
To explore the role of the volatiles emitted from male labial gland (LG) of the bumblebee Bombus ardens ardens, we investigated the responses of virgin queens and males to volatiles using a gas chromatography–electroantennographic detector (GC–EAD) system and Y-tube olfactometer. GC–EAD analysis revealed that citronellol, the main compound detected in the male LG, caused clear electrophysiological responses in the antennae of B. a. ardens virgin queens and males although two minor compounds elicited antennal responses when applied in a high concentration. Behavioral tests using a Y-tube olfactometer showed that queens and males were significantly attracted to both LG extracts and citronellol more than to the solvent alone. This is the first study to demonstrate that citronellol as a major compound of male scent-marking pheromone in B. a. ardens functions as a sex attractant for queens. The results also suggest that this compound has another function as a trail marker used by males. 相似文献
964.
Marco Basile Antonio Romano Andrea Costa Mario Posillico Daniele Scinti Roger Aldo Crisci Ranieri Raimondi Tiziana Altea Vittorio Garfì Giovanni Santopuoli Marco Marchetti Sebastiano Salvidio Bruno De Cinti Giorgio Matteucci 《Die Naturwissenschaften》2017,104(9-10):80
Many small terrestrial vertebrates exhibit limited spatial movement and are considerably exposed to changes in local environmental variables. Among such vertebrates, amphibians at present experience a dramatic decline due to their limited resilience to environmental change. Since the local survival and abundance of amphibians is intrinsically related to the availability of shelters, conservation plans need to take microhabitat requirements into account. In order to gain insight into the terrestrial ecology of the spectacled salamander Salamandrina perspicillata and to identify appropriate forest management strategies, we investigated the salamander’s seasonal variability in habitat use of trees as shelters in relation to tree features (size, buttresses, basal holes) and environmental variables in a beech forest in Italy. We used the occupancy approach to assess tree suitability on a non-conventional spatial scale. Our approach provides fine-grained parameters of microhabitat suitability and elucidates many aspects of the salamander’s terrestrial ecology. Occupancy changed with the annual life cycle and was higher in autumn than in spring, when females were found closer to the stream in the study area. Salamanders showed a seasonal pattern regarding the trees they occupied and a clear preference for trees with a larger diameter and more burrows. With respect to forest management, we suggest maintaining a suitable number of trees with a trunk diameter exceeding 30 cm. A practice of selective logging along the banks of streams could help maintain an adequate quantity of the appropriate microhabitat. Furthermore, in areas with a presence of salamanders, a good forest management plan requires leaving an adequate buffer zone around streams, which should be wider in autumn than in spring. 相似文献
965.
Poor early-life nutrition could reduce adult reproductive success by negatively affecting traits linked to sexual attractiveness such as song complexity. If so, this might favor strategic mate choice, allowing males with less complex songs to tailor their mating tactics to maximize the reproductive benefits. However, this possibility has been ignored in theoretical and empirical studies. By manipulating the micronutrient content of the diet (e.g., low or high) during the postnatal period of male zebra finches, we show for the first time (1) that males reared on a poor (low) micronutrient diet had less complex songs as adults; (2) that these males, in contrast to the high micronutrient diet group, were more selective in their mating strategies, discriminating against those females most likely to reduce their clutch size when paired with males having less complex songs; and (3) that by following different mating strategies, males reared on the contrasting diets obtained similar reproductive benefits. These results suggest that early-life dietary conditions can induce multiple and long-lasting effects on male and female reproductive traits. Moreover, the results seem to reflect a previously unreported case of adaptive plasticity in mate choice in response to a nutritionally mediated reduction in sexual attractiveness. 相似文献
966.
Robert Liu R.S. Shieh Ruth Y.L. Yeh C.H. Lin 《Waste management (New York, N.Y.)》2009,29(11):2842-2845
The traditional burning process is used to recover copper from scrapped PC board (printed circuit board) but it causes serious environmental problems. In this research a new process was developed which not only prevents pollution problems, but also maximizes the utility of all the materials on the waste board. First, the scrapped PC board was crushed and grounded, then placed in the NH3/NH5CO3 solution with aeration in order to dissolve copper. After distilling the copper NH3/NH5CO3 solution and then heating the distilled residue of copper carbonate, pure copper oxide was obtained with particle size of about 0.2 μm and the shape elliptical. The remaining solid residue after copper removal was then leached with 6 N hydrochloric acid to remove tin and lead. The last residue was used as a filler in PVC plastics. The PVC plastics with PC board powder as filling material was found to have the same tensile strength as unfilled plastics, but had higher elastic modulus, higher abrasion resistance, and was cheaper. 相似文献
967.
Preeclampsia (PE), which affects about 2% of pregnancies, is a major cause of maternal and perinatal morbidity and mortality. PE can be subdivided into early onset PE with delivery <34 weeks' gestation and late onset PE with delivery ≥34 weeks. Early onset PE is associated with a higher incidence of adverse outcome. This review illustrates that effective screening for the development of early onset PE can be provided in the first-trimester of pregnancy. Screening by a combination of maternal risk factors, mean arterial pressure, uterine artery Doppler, maternal serum pregnancy-associated plasma protein-A and placental growth factor can identify about 95% of cases of early onset PE for a false-positive rate of 10%. © 2014 John Wiley & Sons, Ltd. 相似文献
968.
969.
Each year more people die from diseases caused by work than are killed in industrial accidents. Therefore, methods are needed to evaluate occupational health hazards as early as possible when the process is still under development. A method for estimating inhalative exposures and risks in petrochemical and related plants is presented. The method is simple and suffices with the limited data availability during the early design stages.The steps of the method, which utilizes preliminary process flow diagrams are as follows: first the fugitive emissions and process plot areas are estimated based on precalculated process modules representing the typical process sections (such as a distillation unit). Chemical concentration in the air is then calculated based on the wind velocity probability and the estimated process cross-sectional area. For this purpose a typical wind velocity distribution in the area is used. The worker risk of exposure to chemicals is evaluated either based on the concentration in air by using the hazard quotient method or calculating the carcinogenic chemicals intake and the resulting risk of cancer. The values are compared to the benchmarks.As a result the process route health characteristics such as fugitive emissions rate, critical wind speed, chemical concentration in air and intake amount as well as the corresponding risk of exposure are produced. By using statistical meteorological data, health risks of occupational exposure can be estimated more realistically as probabilities. The approach is capable of comparing alternative processes to select the concept which is inherently occupationally healthier. Using this method, the exposure problems of a process can be identified earlier and proper decisions can be made early in process development or predesign stage.The concentration-based method is demonstrated by a case study of six competing manufacturing routes for methyl methacrylate (MMA). The C3 is found to be the most harmful alternative to health. Both concentration-based and intake-based methods are applied. The study indicates that the intake-based risk estimation benchmark is stricter than the exposure limit-based benchmark for carcinogens. 相似文献
970.
Emmanuel C. Gentil Anders Damgaard Michael Hauschild Göran Finnveden Ola Eriksson Susan Thorneloe Pervin Ozge Kaplan Morton Barlaz Olivier Muller Yasuhiro Matsui Ryota Ii Thomas H. Christensen 《Waste management (New York, N.Y.)》2010,30(12):2636-2648
A number of waste life cycle assessment (LCA) models have been gradually developed since the early 1990s, in a number of countries, usually independently from each other. Large discrepancies in results have been observed among different waste LCA models, although it has also been shown that results from different LCA studies can be consistent. This paper is an attempt to identify, review and analyse methodologies and technical assumptions used in various parts of selected waste LCA models. Several criteria were identified, which could have significant impacts on the results, such as the functional unit, system boundaries, waste composition and energy modelling. The modelling assumptions of waste management processes, ranging from collection, transportation, intermediate facilities, recycling, thermal treatment, biological treatment, and landfilling, are obviously critical when comparing waste LCA models.This review infers that some of the differences in waste LCA models are inherent to the time they were developed. It is expected that models developed later, benefit from past modelling assumptions and knowledge and issues. Models developed in different countries furthermore rely on geographic specificities that have an impact on the results of waste LCA models. The review concludes that more effort should be employed to harmonise and validate non-geographic assumptions to strengthen waste LCA modelling. 相似文献