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951.
Despite the plentiful diversity of macroalgae in coastal environments, few studies have examined the in vivo absorption features of common marine macrophytes. Here we report on results of a survey of 12 central California common intertidal and subtidal taxa, representing Chlorophyta, Phaeophyta and Rhodophyta carried out in the summer of 1988. Computer-assisted analyses were used to obtain fourth-derivative spectra from in vivo absorption spectra determined at room temperature to obtain spectral diagnostics for the different algal divisions and to provide a means to determine whether spectral features could be used to identify stress responses among these plants. Among the Chlorophyta, characteristic maxima for chlorophylls a and b were resolved in all species examined, and a spectral component attributable to siphonaxanthin-like carotenoid(s) was observed in two Ulva species and the coenocytic alga Derbesia marina. Representatives of the Phaeophyta were characterized by similar maxima for chlorophyll a and c, and for fucoxanthin. Among the Rhodophyta, maxima for chlorophyll a, as well as B- and R-type phycoerythrin were resolved. Differences in in vivo absorption features were detected for two tidal populations of Porphyra perforata and Mastocarpus papillatus. High-tidal thalli absorb less green light in regions characterized by phycoerythrin, but have enhanced carotenoid absorption compared with lowtidal thalli. Resolution of spectra by fourth-derivative analysis revealed significant differences in phycoerythrin and carotenoid contents. The spectral changes observed appear to reflect environmental and possibly populational characteristics of these algae. The spectral analyses described here provide robust, non-invasive means to characterize subtle responses of macroalgae to environment in ways not possible previously. Additional merits of these fourth-derivative analyses for use in environmental studies are discussed.This contribution is dedicated to the memory of Professor L. R. Blinks, a pioneer in photosynthesis research and algal physiology 相似文献
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954.
Jody N. Connor Gerald N. Smith 《Journal of the American Water Resources Association》1986,22(4):661-664
ABSTRACT: Alum and sodium aluminate were injected into the hypolimnion of eutrophic Kezar Lake, New Hampshire, with a specially designed applicator mechanism. This new method of applying aluminum salts to achieve phosphorus inactivation included two separate chemical distribution systems mounted on a hydraulic weed harvester. The design of the applicator system is described, and its cost-effectiveness is compared with other aluminum salt injections. 相似文献
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956.
Tracer kinetic analysis of radioisotope incorporation into dissolved organic compounds reveals two distinct patterns of photosynthate release by macroalgae. In experiments employing Sargassum lacerifolium, dissolved organic carbon was produced at a constant rate during light incubations. Steady state rates of production were never achieved in experiments employing either Ecklonia radiata (Turn.) J. Agardh. or Ulva lactuca L. Analysis of the time-varying radioactivity curves obtained in experiments using these algae always resulted in models consistent with dissolved organic carbon production being an autocatalytic process. Preincubation of U. lactuca in the dark resulted in a diminished (ca. 40%) rate of dissolved organic carbon production during the subsequent light incubations. In no case did the radioisotope content of the dissolved organic carbon approach a limiting value, indicating that in contrast to phytoplankton, uptake rates of photosynthate by macroalgae are always less than the rates of production. 相似文献
957.
Genetic variation was studied at two polymorphic loci for 3 yr (November 1978–February 1982) in juvenile sand flounder (Rhombosolea plebeia) in Wellington Harbour, New Zealand. The Gpi-1 locus showed a heterogeneity in genotype frequencies, but this was not clearly related to season or to fish length. At the Gpi-2 locus, genotype frequencies were dependent upon length and showed a significant excess of homozygotes in juveniles but not in adults. This latter phenomenon has been reported previously in several species of marine molluscs, and so may be common to marine organisms producing large numbers of pelagic larvae. Reasons for the excess of homozygotes are discussed, and it is suggested that assortative mating is the most likely explanation and that this is an area of marine population genetic research which has been over-looked. 相似文献
958.
France Lamy John Bolte Mary Santelmann Courtland Smith 《Journal of the American Water Resources Association》2002,38(2):517-529
ABSTRACT: Making decisions for environmental management is a complex task due to the multiplicity and diversity of technological choices. Furthermore, the exploitation of natural resources and the preservation of the natural environment imply objectives that are often in conflict within a sustainable development paradigm. Managers and other decision makers require techniques to assist them in understanding strategic decision making. This paper illustrates the use of a multiple‐objective decision‐making methodology and an integrative geographical information system‐based decision‐making tool developed to help watershed councils prioritize and evaluate restoration activities at the watershed level. Both were developed through a multidisciplinary approach. The decision‐making tool is being applied in two watersheds of Oregon's Willamette River Basin. The results suggest that multiple‐objective methods can provide a valuable tool in analyzing complex watershed management issues. 相似文献
959.
Scott A. Smith 《环境质量管理》1997,6(3):43-47
Companies today are continuously improving their efforts to incorporate an environmental management system (EMS) in their everyday operations and work practices, with an emphasis on identifying and reducing risks. Risks may include the cost of enforcement penalties, potential workplace dangers to employees, or cleanup liabilities due to past or present practices. Environmental auditing is an effective tool commonly used to enhance an EMS. Typically, there are two levels of auditing: (1) a review of management systems and (2) a review of compliance with regulatory requirements. There is yet another intermediate level of auditing that is more focused than management systems or compliance audits—compliance delivery systems (CDS) audits. This article examines the elements making up these systems for improving compliance performance and provides a ?ready to use”? checklist of items for managers to begin implementation. 相似文献
960.
The Millville Remediation Program recently received the 1995 Honor Award for national excellence in environmental engineering from the prestigious American Academy of Environmental Engineers (AAEE). This article discusses various aspects employed to investigate and remediate multimedia contamination at the site and the unique applications of technologies which were responsible for receiving the AAEE honor award. Unique aspects of the project included utilization of variable speed drives to set individual pumping rates for each groundwater recovery well, development of sophisticated remote monitoring and operation capabilities which minimized O&M labor costs, and development of a groundwater treatment system which has consistently achieved nondetect effluent discharges. The remote monitoring and operation capabilities enables O&M staff to monitor and change setpoints for the groundwater recovery, treatment, and recharge systems. 相似文献