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761.
香格里拉在人们心中代表着永恒、宁静、和平。香格里拉具有以下特点 :(1)以大自然为背景 ;(2 )强调人与人及人与大自然的和谐共生 ;(3)以生态学思想和可持续发展思想为指导 ;(4)是一种特殊的生态旅游地。依据可持续发展理论 ,认为香格里拉生态旅游业开发是自然和人文保护事业和旅游业可持续发展的需要 ;也是积极保护香格里拉的有效手段。最后 ,结合云南迪庆藏族自治州中甸香格里拉生态旅游资源特色 ,按照保护为主、科技引导、适度开发、保护与开发和科研相结合的原则 ,提出了构建生态旅游决策支持系统、加强旅游区规划、开展科学研究、建立一支素质较高的生态旅游人才队伍、加强生态环境教育、提高公众环境意识、制定适当的地方性旅游政策法规等开发本区生态旅游的一些基本措施。 相似文献
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764.
Xiaorong Wei Yanjiang Zhang Jian Liu Hailong Gao Jun Fan Xiaoxu Ji Jimin Cheng Mingan Shao Xingchang Zhang 《环境科学学报(英文版)》2016,28(7):207-214
Soil CO_2efflux(SCE) is an important component of ecosystem CO_2 exchange and is largely temperature and moisture dependent, providing feedback between C cycling and the climate system. We used a precipitation manipulation experiment to examine the effects of precipitation treatment on SCE and its dependences on soil temperature and moisture in a semiarid grassland. Precipitation manipulation included ambient precipitation, decreased precipitation(- 43%), or increased precipitation(+ 17%). The SCE was measured from July2013 to December 2014, and CO_2 emission during the experimental period was assessed.The response curves of SCE to soil temperature and moisture were analyzed to determine whether the dependence of SCE on soil temperature or moisture varied with precipitation manipulation. The SCE significantly varied seasonally but was not affected by precipitation treatments regardless of season. Increasing precipitation resulted in an upward shift of SCE–temperature response curves and rightward shift of SCE–moisture response curves,while decreasing precipitation resulted in opposite shifts of such response curves. These shifts in the SCE response curves suggested that increasing precipitation strengthened the dependence of SCE on temperature or moisture, and decreasing precipitation weakened such dependences. Such shifts affected the predictions in soil CO_2 emissions for different precipitation treatments. When considering such shifts, decreasing or increasing precipitation resulted in 43 or 75% less change, respectively, in CO_2 emission compared with changes in emissions predicted without considering such shifts. Furthermore, the effects of shifts in SCE response curves on CO_2 emission prediction were greater during the growing than the non-growing season. 相似文献
765.
Kassaye Ashenafi Yimam Shao Guangcheng Wang Xiaojun Belete Marye 《Environment, Development and Sustainability》2022,24(1):724-764
Environment, Development and Sustainability - The geocybernetic assessment matrix (GAM) evaluation of climate-smart agriculture (CSA) practices in Ethiopia is carried out in this paper. With regard... 相似文献
766.
运用生态足迹方法对辽宁省2000年-2009年生态足迹和生态承载力进行了计算,并对辽宁省可持续发展程度进行了分析和预测。结果表明2000年-2009年期间辽宁省人均生态足迹快速增长,增幅达58.5%;而人均生态承载力基本不变,造成其生态赤字不断加大,涨幅达73.7%,生态系统处于一种不可持续发展状态。在此基础上利用非线性回归预测模型,对辽宁省未来十年的生态赤字进行了预测。并根据辽宁省近年来可持续发展与经济发展状况,提出遏制生态环境恶化、促进区域可持续发展的一些建议。 相似文献
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60° inclined dense jets had been recommended for brine discharges from desalination plants to achieve a maximum mixing efficiency.
However, the terminal rise associated with 60° is relatively high and thus the angle may be too large for disposal in shallow
coastal wasters. In this study, we investigate the mixing behavior of dense jets discharging at smaller angles of 30° and
45° in a stationary ambient. Combined Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) were used
as the measurement approaches that captured the velocity and concentration fields, respectively. Based on the experimental
results, the characteristic geometrical features of the inclined dense jets, including the location of the centerline peak
and the return point where the dense jet returns to the source level, etc., are quantified. The mixing and diluting behaviors
are also revealed through the analysis of the axial and cross-sectional velocity and concentration profiles. In addition to
the free inclined discharges, the present study also examines the effect of the proximity to the bed. Through the comparison
of the results between two experimental series with distinct z
0/D but overlapping z
0/L
M
, the latter is identified as the deciding factor for the boundary influence. 相似文献
769.
Xianjun He Bin Yuan Caihong Wu Sihang Wang Chaomin Wang Yibo Huangfu Jipeng Qi Nan M Wanyun Xu Ming Wang Wentai Chen Hang Su Yafang Cheng Min Shao 《环境科学学报(英文版)》2022,34(4):98-114
The characteristics of wintertime volatile organic compounds (VOCs) in the North China Plain (NCP) region are complicated and remain obscure. VOC measurements were conducted by a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) at a rural site in the NCP from November to December 2018. Uncalibrated ions measured by PTR-ToF-MS were quantified and the overall VOC compositions were investigated by combining the measurements of PTR-ToF-MS and gas chromatography-mass spectrometer/flame ionization detector (GC-MS/FID). The measurement showed that although atmospheric VOCs concentrations are often dominated by primary emissions, the secondary formation of oxygenated VOCs (OVOCs) is non-negligible in the wintertime, i.e., OVOCs accounts for 42% ± 7% in the total VOCs (151.3 ± 75.6 ppbV). We demonstrated that PTR-MS measurements for isoprene are substantially overestimated due to the interferences of cycloalkanes. The chemical changes of organic carbon in a pollution accumulation period were investigated, which suggests an essential role of fragmentation reactions for large, chemically reduced compounds during the heavy-polluted stage in wintertime pollution. The changes of emission ratios of VOCs between winter 2011 and winter 2018 in the NCP support the positive effect of “coal to gas” strategies in curbing air pollutants. The high abundances of some key species (e.g. oxygenated aromatics) indicate the strong emissions of coal combustion in wintertime of NCP. The ratio of naphthalene to C8 aromatics was proposed as a potential indicator of the influence of coal combustion on VOCs. 相似文献
770.
石化企业工程项目施工作业过程中,潜在着极大的风险.既具有作业面狭窄、高处作业交叉集中、用火用电频繁的一般特征,又兼具大型吊装、火灾爆炸、危险品泄漏等重大危险因素.由于作业中不可预见因素多、管理难度大,一旦HSE管理不到位,极易发生火灾、爆炸、中毒、环境污染等各类事故.根据石化企业以往所发生事故的统计,承包商违章或对承包商管理环节失控所导致的事故占到相当大的比例.因此对承包商进行全过程、系统化的监控管理非常重要. 相似文献