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961.
962.
城市声环境功能区划中的3S技术应用探索 总被引:1,自引:1,他引:0
探索3S技术在声环境功能区划中的应用.根据噪声的相关标准规范,应用3S技术开展桂林城区声环境普查和声功能区划的划分.结合传统的噪声监测评价方法和模糊数学聚类方法,探讨3S资源利用和精度控制、GPS应用、影像解译和GIS空间分析中的作用、特点及问题.3S技术使监测部门拥有获取城市基础数据的能力. 相似文献
963.
In this paper we introduce a new method of analysing the relationship between nitrogen dioxide (NO2) and oxides of nitrogen (NOx) concentrations using data from the UK National Air Quality Archive. The study includes analyses of measurements from two different types of site in London, a kerbside site: Cromwell Rd, and three background sites: Bridge Place, London Bloomsbury and West London, over several years (1991–7). The data in some years showed that hourly NO2 concentrations exceeded the UK Standard of 150 ppb. Data were binned, averaged, and polynomials fitted at each site. Analysis of the resulting polynomials was used to estimate reductions in NOx emission required to achieve the National Air Quality Strategy Objective. Examination of the empirical ratio NO2:NOx (the 'yield') gives an indication of the sensitivity of the NO2 to NOx controls and the amount of NO2 that would arise from modelled values of total oxides of nitrogen. The response of NO2 to emission changes is very non-linear, implying 30–45% controls on NOx may be required. 相似文献
964.
空气污染对儿童肺功能指标影响的初步分析 总被引:14,自引:3,他引:11
报告中国 4城市 8所小学儿童肺功能指标受室外空气污染影响的结果。以 FVC/预测值 (85% )、FEV1 /预测值(85% )、FEV1 / FVC(实测值之比 ) (80 % )作为判断肺功能指标异常的参考标准 ,并将 8所小学按污染程度分为污染严重和污染较轻两类三组。污染严重组儿童肺功能指标的异常率均比污染较轻组要高。空气的严重污染 ,可使儿童肺功能FVC、FEV1 、FEV1 / FVC异常率的危险程度分别增高 3 0 %~ 78%、52 %~ 86%和 1 0 2 %~ 1 2 7%。异常组儿童的 FVC、FEV1 的平均值约下降 3 3 0~ 4 60 ml,FEV1 / FVC平均值约下降 1 3 %~ 1 5%。说明空气的严重污染对儿童肺功能生长发育可能有不利影响 相似文献
965.
针对目前水质综合评价中常规方法存在的问题 ,提出了径向基函数网络模型 (简记为 RBF-ANN)。以吉林省白城市地下潜水水质资料为例 ,运用该方法对监测样点进行了综合评价。通过与其它方法对比 ,结果表明 ,利用RBF-ANN模型进行水环境质量综合评价不仅方法简便 ,而且结论更接近客观实际。 相似文献
966.
In this study, we present the application of the passive microwave emission models to snow-cover environment monitoring and
assessment in Northeast China. The study employs the radiative transfer function and strong fluctuation theory to develop
the models. We used the exponential form of a spherical symmetric correlation function to describe random permittivity fluctuations.
From strong fluctuation, we then obtained the phase matrix and extinction coefficients of snow-packs for the spherical symmetric
correlation function. We also used the vector radiative transfer formula for the layer of a random medium by solving Gaussian
quadrature and eigen analysis. By comparing the brightness temperatures at 5, 10.7, 18, and 37 GHz, the modelling results
agreed with experimental data of dry-snow physical parameters as measured in the fieldwork. 相似文献
967.
Masto RE Chhonkar PK Singh D Patra AK 《Environmental monitoring and assessment》2008,136(1-3):419-435
Soil quality assessment provides a tool for evaluating the sustainability of alternative soil management practices. Our objective
was to develop the most sensitive soil quality index for evaluating fertilizer, farm yard manure (FYM), and crop management
practices on a semiarid Inceptisol in India. Soil indicators and crop yield data from a long-term (31 years) fertilizer, manure,
and crop rotation (maize, wheat, cowpea, pearl millet) study at the Indian Agricultural Research Institute (IARI) near New
Delhi were used. Plots receiving optimum NPK, super optimum NPK and optimum NPK + FYM had better values for all the parameters
analyzed. Biological, chemical, and physical soil quality indicator data were transformed into scores (0 to 1) using both
linear and non-linear scoring functions, and combined into soil quality indices using unscreened transformations, regression
equation, or principal component analysis (PCA). Long-term application of optimum inorganic fertilizers (NPK) resulted in
higher soil quality ratings for all methods, although the highest values were obtained for treatment, which included FYM.
Correlations between wheat (Triticum aestivum L.) yield and the various soil quality indices showed the best relationship (highest r) between yield and a PCA-derived SQI.
Differences in SQI values suggest that the control (no NPK, no manure) and N only treatments were degrading, while soils receiving
animal manure (FYM) or super optimum NPK fertilizer had the best soil quality, respectively. Lower ratings associated with
the N only and NP treatments suggest that one of the most common soil management practices in India may not be sustainable.
A framework for soil quality assessment is proposed. 相似文献
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