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251.
John Shupe Christopher Potter 《Journal of the American Water Resources Association》2014,50(1):153-162
This study describes the application of the NASA version of the Carnegie‐Ames‐Stanford Approach (CASA) ecosystem model coupled with a surface hydrologic routing scheme previously called the Hydrological Routing Algorithm (HYDRA) to model monthly discharge rates from 2000 to 2007 on the Merced River drainage in Yosemite National Park, California. To assess CASA‐HYDRA's capability to estimate actual water flows in extreme precipitation years, the focus of this study is the 2007 water year, which was very dry, and the 2005 water year, which was a moderately wet year in the historical record. Prior to comparisons to gauge records, CASA‐HYDRA snowmelt algorithms were modified with equations from the U.S. Department of Agriculture Snowmelt‐Runoff Model (SRM), which has been designed to predict daily streamflow in mountain basins where snowmelt is a major runoff factor. Results show that model predictions closely matched monthly flow rates at the Pohono Bridge gauge station (USGS#11266500), with R2 = 0.67 and Nash‐Sutcliffe (E) = 0.65. By subdividing the upper Merced River basin into subbasins with high spatial resolution in the gridded modeling approach, we were able to determine which biophysical characteristics in the Sierra differed to the largest degree in extreme low‐flow and high‐flow years. Average elevation and snowpack accumulation were found to be the most important explanatory variables to understand subbasin contributions to monthly discharge rates. 相似文献
252.
253.
产业园生态效率评价——以九发生态产业园为例 总被引:2,自引:0,他引:2
生态产业园区的发展和评价已成为包括我国在内的全球产业可持续发展研究的热点领域。生态效率指标强调以较少资源投入和较低污染排放生产更多较高质量的产品,能同时评价经济效益和环境效益,符合人类可持续发展目标,现已是指导和评价生态工业园可持续发展建设的有效工具。本文应用生态效率理论和方法,对2004年九发生态产业园的运行情况进行了效率评价和生态功能探讨,并与同年全国平均生态效率指标进行了对比,发现九发生态产业园虽然产业链网较完善,但系统实际运行的生态效率高低不一。其中,单位原材料产出率和单位废水排放产出率指标明显低于全国平均水平,表明系统的生态功能发挥不足。因此,需进一步提高九发生态产业园的资源利用效率和能源使用效率,从而增加其经济效益和环境效益、促进其可持续发展。 相似文献
254.
Weichuan Qiao Rong Li Tianhao Tang Achuo Anitta Zuh 《Frontiers of Environmental Science & Engineering》2021,15(2):20
255.
云蒙山国家森林公园内部旅游解说系统的改善 总被引:11,自引:2,他引:11
改进旅游解说系统是全面改善旅游景区管理的重要环节.以云蒙山国家森林公园为例,通过对游客的问卷调查获取一手资料,在简要阐明旅游解说系统概念、原则与目标以及与游客特征的关系的基础上,总结了公园内部旅游解说系统目前存在的问题,并通过对公园游客相关特征的分析,对公园内部旅游解说系统的改进提出了建议. 相似文献
256.
257.
本文分析了琅琊山国家森林公园生物资源的生存环境和现状.提出了相应的保护与开发利用对策。 相似文献
258.
We examined the geology of a small inland wetland in Hampton, Connecticut to determine its postglacial history and to assess
the severity of human impact at this remote wooded site. Using stratigraphic evidence, we dernonstrate that the present wetland
was created when sediment pollution from a 19th-century railroad filled a preexisting artificial reservoir, and that the prehistoric
wetland was a narrow drainage swale along Hampton Brook. This same, severely impacted wetland was interpreted by the Pulitzer
Prize-winning naturalist Edwin Way Teale as a beautiful wilderness area of particular interest. These conflicting perceptions
indicate that artificial wetlands can be naturally mitigated in less than a century of healing, even in the absence of deliberate
management. We also point out that the “wilderness” value of the Teale wetland was in the eye of the beholder and that unseen
human impacts may have improved the aesthetic experience. 相似文献
259.
In order to balance pressures for land-use development with protection of wetland resources, artificial wetlands have been
constructed in an effort to replace lost ecosystems. Despite its regulatory appeal and prominent role in current mitigation
strategies, it is unclear whether or not created systems actually compensate for lost wetland resources. Mitigation predictions
that rely on artificial wetlands must be analyzed critically in terms of their efficacy. Destruction of wetlands due to burial
by coal fly ash at a municipal landfill in Danvers, Massachusetts, USA, provided an opportunity to compare resulting growth
of created cattail (Typha) marshes with natural wetland areas. Once the appropriate cattail species was identified for growth under disturbed landfill
conditions, two types of artificial wetlands were constructed. The two systems differed in their hydrologic attributes: while
one had a surface water flow characteristic of most cattail wetlands, the second system mimicked soil and water conditions
found in naturally occurring floating cattail marshes. Comparison of plant growth measurements for two years from the artificial
systems with published values for natural cattail marshes revealed similar structure and growth patterns. Experiments are
now in progress to investigate the ability of created cattail marshes to remove and accumulate heavy metals from polluted
landfill leachate. Research of the type reported here must be pursued aggressively in order to document the performance of
artificial wetlands in terms of plant structure and wetland functions. Such research should allow us to start to evaluate
whether artificial systems actually compensate for lost wetlands by performing similar functions and providing the concomitant
public benefits. 相似文献
260.
Over the last decade the Great Smoky Mountains National Park (GSMNP) has experienced a tremendous increase in visitation, especially in backcountry camping. In 1976 there were an estimated 117,500 backcountry visitor nights, with a peak of 16,865 visitor nights in April. The high use season extends from March to October. Visitation tends to be concentrated in certain sections of the park and at specific sites. The Appalachian Trail, which includes about 8 percent of the maintained trail mileage, carried 32 percent of the visitor nights in 1976.Campsite disturbance is also concentrated in specific sites and sections of the park. Maximum camping disturbance per km of maintained trail was 3,400 m2 for the sites on the Appalachian Trail. Shelter sites have more visitation per site and more total disturbance per site than open campsites, but shelters tend to have less intensive disturbance, such as bare soil, because they concentrate trampling impacts. Visitation levels were strongly correlated with disturbances such as bare soil at open campsites. Visitation was significantly correlated to the number of firepits at shelter sites but not to other types of disturbance. Regressions indicate that for each additional visitor night at a site (annual average), one can expect an additional 9 m2 of total disturbance and 1 m2of bare soil. The distance of a site from the nearest road was not significantly correlated with damage or visitation. Elevation was correlated to visitation levels, especially in the case of the shelters. More legal sites and large illegal sites are in mesic forest types. Illegal camping accounted for 10 percent of the total camping disturbance.The data imply that the suggested removal of shelters will require redistribution of visitor use or replacement developments, such as tent platforms, in order to mitigate damage. Zone camping is a possible alternative but presents difficulties because campers may concentrate in certain plant communities and topographic positions. 相似文献