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341.
Detailed analysis of the land cover of the Estonian coastal zone is presented based on Estonian laws on coastal zone management,
the CORINE Land Cover (CLC) system, the status of protected areas, and administrative division data of Estonia. By law the
coastal zone is defined as a 200-m wide zone landward from the mean sea level line. The length of the Estonian coastline (including
the islands) is 3794 km. The 200-m zone of the Estonian coast is very diverse. Out of the 34 CORINE land cover types represented
in Estonia 30 are found in the coastal zone. Three dominating land cover types in the coastal zone of Estonia are inland marshes,
coniferous forest and semi-natural grassland. Their total share is 47%; the other 27 land cover types represented here cover
53% of the coastal zone. The Estonian coastal zone is generally in a good natural condition. The proportion of artificial
surfaces throughout the zone is merely 4.7%, while agricultural landscapes cover only ca. 10%. Land cover data for the coastal
zone are also presented by county. Of the 200-m coastal zone 24% is under protection, which is more than twice the value for
Estonia as a whole (11%). Legislative protection of the coastal zone is presently satisfactory. The use of the CORINE Land
Cover system enables comparisons with other European regions since CLC data have been compiled for most of Europe. 相似文献
342.
Paula C. Díaz Christoph Grüter Walter M. Farina 《Behavioral ecology and sociobiology》2007,61(10):1589-1597
Floral scents are important information cues used to organize foraging-related tasks in honeybees. The waggle dance, apart
from encoding spatial information about food sources, might facilitate the transfer of olfactory information by increasing
the dissipation of volatiles brought back by successful foragers. By assuming that food scents are more intensive on specific
body parts of returning foragers, i.e., the posterior legs of pollen foragers and mouthparts of nectar foragers, we quantified
the interactions between hive mates and foragers during dances advertising different types of food sources. For natural sources,
a higher proportion of hive mates contacted the hind legs of pollen dancers (where the pollen loads were located) with their
heads compared to non-pollen dancers. On the other hand, the proportion of head-to-head contacts was higher for non-pollen
foragers during the waggle runs. When the food scent was manipulated, dancers collecting scented sugar solution had a higher
proportion of head-to-head contacts and a lower proportion around their hind legs compared to dancers collecting unscented
solution. The presence of food odors did not affect in-hive behaviors of dancers, but it increased the number of trophallaxes
in-between waggle runs (i.e., during circle phases). These results suggest that the honeybee dance facilitates the olfactory
information transfer between incoming foragers and hive mates, and we propose that excitatory displays in other social insect
species serve the same purpose. While recent empirical and theoretical findings suggested that the colony level foraging benefits
of the spatial information encoded in the waggle dance vary seasonally and with habitats, the role of the dance as a compound
signal not only indicating the presence of a profitable resource but also amplifying the information transfer regarding floral
odors may be important under any ecological circumstances. 相似文献
343.
344.
环境管理信息系统建设中应注意的几个问题 总被引:1,自引:0,他引:1
提出基础数据库是整个环境信息管理系统建设的关键;尤其是系统开发中要注意结构设计.采用成熟、实用及先进的技术;建立先进、安全、开放的网络系统;系统开发的步骤要规范,系统建设中要健全环境信息管理制度,保证系统建设顺利、有序的进行并重视GIS的应用等. 相似文献
345.
介绍了基于GIS的环境信息系统及其在我国的发展过程,并把这个发展过程分为四个阶段:探索阶段、技术成熟阶段、两极分化阶段、市场化阶段;还介绍了两个重要的环境信息系统:中国省级环境信息系统和中国环境监理信息系统。最后,本文展望了中国环境信息系统的发展方向。 相似文献
346.
347.
中国西北地区生态需水研究(2)——基于遥感和地理信息系统技术的区域生态需水计算及分析 总被引:63,自引:1,他引:63
在西北干旱、半干旱地区,随着人口增长和经济发展,国民经济需水与生态环境需水成为水资源开发利用和生态环境保护的主要矛盾。因此,合理量化生态环境需水是西北水资源优化配置亟待解决的问题。论文着重研究两方面的内容:一是基于植被生长需水的区域分异规律,采用遥感和地理信息系统技术实现生态的空间分区,以生态分区和流域水平衡为基础量化生态需水;二是基于可持续发展的生态模式,确定生态保护目标和生态建设规模,并预测生态需水。 相似文献
348.
349.
Curtis B. Barrett 《Journal of the American Water Resources Association》1993,29(6):933-938
ABSTRACT: The National Oceanic and Atmospheric Administration is developing a river forecast system for the Nile River in Egypt. The river forecast system operates on scientific work stations using hydrometeorological models and software to predict inflows into the high Aswan Dam and forecast flow hydrographs at selected gaging locations above the dam The Nile Forecasting System (NFS) utilizes satellite imagery from the METEOSAT satellite as the input to the forecast system. Satellite imagery is used to estimate precipitation over the Blue Nile Basin using five different techniques. Observed precipitation data and climatic statistics are used to improve precipitation estimation. Precipitation data for grid locations are input to a distributed water balance model, a hill slope routing model, and a channel routing model. A customized Geographic Information System (GIS) was developed to show political boundaries, rivers, terrain elevation, and gaging network. The GIS was used to develop hydrologic parameters for the basin and is used for multiple display features. 相似文献
350.
Kyle E. Juracek Joan F Kenny 《Journal of the American Water Resources Association》1993,29(6):973-979
ASSTRACT: As part of its mission, the U.S. Geological Survey conducts water-resources research. Site-specific and aggregate water-use data are used in the Survey's National Water-Use Information Program and in various hydrologic investigations. Both types of activities have specific requirements in terms of water-use data access, analysis, and display. In Kansas, the Survey obtains water-use information from several sources. Trpically, this information is in a format that is not readily usable by the Survey. Geographic information system (GIS) technology is being used to restructure the available water-use data into a format that allows users to readily access and summarize site-specific water-use data by source (i.e., surface or ground water), type of use, and user-defined area. 相似文献