全文获取类型
收费全文 | 15555篇 |
免费 | 1482篇 |
国内免费 | 2243篇 |
专业分类
安全科学 | 2374篇 |
废物处理 | 214篇 |
环保管理 | 3274篇 |
综合类 | 8436篇 |
基础理论 | 1640篇 |
环境理论 | 48篇 |
污染及防治 | 698篇 |
评价与监测 | 1157篇 |
社会与环境 | 1044篇 |
灾害及防治 | 395篇 |
出版年
2024年 | 50篇 |
2023年 | 251篇 |
2022年 | 338篇 |
2021年 | 468篇 |
2020年 | 512篇 |
2019年 | 497篇 |
2018年 | 460篇 |
2017年 | 744篇 |
2016年 | 771篇 |
2015年 | 853篇 |
2014年 | 818篇 |
2013年 | 1132篇 |
2012年 | 1203篇 |
2011年 | 1246篇 |
2010年 | 915篇 |
2009年 | 908篇 |
2008年 | 669篇 |
2007年 | 1015篇 |
2006年 | 982篇 |
2005年 | 841篇 |
2004年 | 700篇 |
2003年 | 667篇 |
2002年 | 525篇 |
2001年 | 490篇 |
2000年 | 477篇 |
1999年 | 344篇 |
1998年 | 257篇 |
1997年 | 235篇 |
1996年 | 162篇 |
1995年 | 191篇 |
1994年 | 106篇 |
1993年 | 115篇 |
1992年 | 68篇 |
1991年 | 45篇 |
1990年 | 33篇 |
1989年 | 25篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 17篇 |
1985年 | 7篇 |
1984年 | 12篇 |
1982年 | 14篇 |
1981年 | 16篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1975年 | 7篇 |
1973年 | 6篇 |
1972年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
采集2015年南昌市冬季大气PM_(2.5)样品,利用电感耦合等离子体质谱仪(ICP-MS)测定样品中重金属(V、Mn、Cr、Co、Ni、Cu、Zn、Cd、Ba和Pb)的含量,分析重金属的分布特征和来源,并对重金属健康风险进行评价。结果表明:采样期间PM2.5浓度总平均值为(29.74±16.82)μg/m~3,其中省外办最高,武术学校最低;各重金属元素总体平均浓度从高到低次序为:ZnPbCuMnBaNiVCrCdCo。因子分析结果表明:PM_(2.5)中重金属元素的来源包括道路交通尘和冶金化工排放、机动车尾气以及混合源。健康风险评价结果显示:PM_(2.5)中Mn对人体健康存在非致癌风险,其他元素(Cr、Ba、Co、Pb、Cd、Cu、V、Zn、Ni)基本没有非致癌风险;Cr对人体有较明显的致癌风险,Cd、Ni和Co对部分年龄段的人群(尤其是成年人)存在一定的致癌风险。 相似文献
92.
David L. Peterson 《Environmental monitoring and assessment》2000,64(1):81-91
A quantitatively robust yet parsimonious air-quality monitoring network in mountainous regions requires special attention to relevant spatial and temporal scales of measurement and inference. The design of monitoring networks should focus on the objectives required by public agencies, namely: 1) determine if some threshold has been exceeded (e.g., for regulatory purposes), and 2) identify spatial patterns and temporal trends (e.g., to protect natural resources). A short-term, multi-scale assessment to quantify spatial variability in air quality is a valuable asset in designing a network, in conjunction with an evaluation of existing data and simulation-model output. A recent assessment in Washington state (USA) quantified spatial variability in tropospheric ozone distribution ranging from a single watershed to the western third of the state. Spatial and temporal coherence in ozone exposure modified by predictable elevational relationships ( 1.3 ppbv ozone per 100 m elevation gain) extends from urban areas to the crest of the Cascade Range. This suggests that a sparse network of permanent analyzers is sufficient at all spatial scales, with the option of periodic intensive measurements to validate network design. It is imperative that agencies cooperate in the design of monitoring networks in mountainous regions to optimize data collection and financial efficiencies. 相似文献
93.
大气环境质量综合评价加权灰色关联模型的建立与应用 总被引:1,自引:2,他引:1
利用灰色理论建立大气环境质量综合评价加权灰色关联模型 ,运用污染贡献率确定权重系数。与其它评价模型相比 ,加权灰色关联模型还具有排序功能 ,实例表明该模型是简便有效的 相似文献
94.
本文从发展我国环境监测技术产业的角度论述了环境监测技术产业的主要内容,分析了我国环境监测技术产业的发展和存在的问题,对发展我国环境监测技术产业提出了建议。 相似文献
95.
96.
锅炉环境影响评价系统软件研究 总被引:3,自引:0,他引:3
用C语言作为开发语言,研制开发了锅炉环境影响评价系统软件,软件充分利用C语言模块化,过程化的优点,源程序由12个模块组成。经编译连接生成一个可执行程序,用户只需输入15个必需的原始参数,软件即可自动查询,计算大量的中间参数,并立即给出污染源强及污染物在周围环境中分布的预测和评价结果。 相似文献
97.
经济手段在环境管理中的作用及涉及到政府与各利益关系人之间的博弈过程。本文就政府与一次性餐具生产者,销售者之间的博弈关系,分析如何应用经济手段使其在防治“白色污染”中发挥更好的作用。 相似文献
98.
A pilot project to detect and forecast harmful algal blooms in the northern Gulf of Mexico 总被引:1,自引:0,他引:1
More timely access to data and information on the initiation, evolution and effects of harmful algal blooms can reduce adverse impacts on valued natural resources and human health. To achieve this in the northern Gulf of Mexico, a pilot project was initiated to develop a user-driven, end-to-end (measurements to applications) observing system. A key strategy of the project is to coordinate existing state, federal and academic programs at an unprecedented level of collaboration and partnership. Resource managers charged with protection of public health and aquatic resources require immediate notice of algal events and a forecast of when, where and what adverse effects will likely occur. Further, managers require integrated analyses and interpretations, rather than raw data, to make effective decisions. Consequently, a functional observing system must collect and transform diverse measurements into usable forecasts. Data needed to support development of forecasts will include such properties as sea surface temperature, winds, currents and waves; precipitation and freshwater flows with related discharges of sediment and nutrients; salinity, dissolved oxygen, and chlorophyll concentrations (in vivo fluorescence); and remotely-sensed spatial images of sea surface chlorophyll concentrations. These data will be provided via a mixture of discrete and autonomous in situ sensing with near real-time data telemetry, and remote sensing from space (SeaWiFS), aircraft (hyperspectral imagery) or land (high-frequency radar). With calibration across these platforms, the project will ultimately provide a 4-dimensional visualization of harmful algae events in a time frame suitable to resource managers. 相似文献
99.
Using improved neural network model to analyze RSP,NOx and NO2 levels in urban air in Mong Kok,Hong Kong 总被引:4,自引:0,他引:4
As the health impact of air pollutants existing in ambient addresses much attention in recent years, forecasting of airpollutant parameters becomes an important and popular topic inenvironmental science. Airborne pollution is a serious, and willbe a major problem in Hong Kong within the next few years. InHong Kong, Respirable Suspended Particulate (RSP) and NitrogenOxides NOx and NO2 are major air pollutants due to thedominant diesel fuel usage by public transportation and heavyvehicles. Hence, the investigation and prediction of the influence and the tendency of these pollutants are ofsignificance to public and the city image. The multi-layerperceptron (MLP) neural network is regarded as a reliable andcost-effective method to achieve such tasks. The works presentedhere involve developing an improved neural network model, whichcombines the principal component analysis (PCA) technique and theradial basis function (RBF) network, and forecasting thepollutant levels and tendencies based in the recorded data. Inthe study, the PCA is firstly used to reduce and orthogonalizethe original input variables (data), these treated variables arethen used as new input vectors in RBF neural network modelestablished for forecasting the pollutant tendencies. Comparingwith the general neural network models, the proposed modelpossesses simpler network architecture, faster training speed,and more satisfactory predicting performance. This improvedmodel is evaluated by using hourly time series of RSP, NOx and NO2 concentrations collected at Mong Kok Roadside Gaseous Monitory Station in Hong Kong during the year 2000. By comparing the predicted RSP, NOx and NO2 concentrationswith the actual data of these pollutants recorded at the monitorystation, the effectiveness of the proposed model has been proven.Therefore, in authors' opinion, the model presented in the paper is a potential tool in forecasting air quality parameters and hasadvantages over the traditional neural network methods. 相似文献
100.
Benchmarking of environmental performance to demonstrate theachievement of best practice environmental management is acomponent of a new form of licensing of industrialdischarges in Western Australia. The paper describes theapproaches to benchmarking for the critical environmentalissues for an alumina refinery and wastewater treatmentplant. It also describes the lessons learnt from thebenchmarking process on appropriate methods, the benefitsand difficulties in the benchmarking process, and changesthat would assist benchmarking for best practiceenvironmental management. 相似文献