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901.
室内空气污染概述   总被引:6,自引:3,他引:6       下载免费PDF全文
由于燃料燃烧、烹饪、人类活动、不合格建材和装饰材料的使用,房屋的密闭性结构等诸多因素,使室内空气污染远高于室外,从而严重地危害人们的健康,甚至导致多种疾病的发生。文章较全面地概述了室内空气污染的来源和类型,对人体的危害情况、目前的分析测试方法和标准样样品状况。  相似文献   
902.
轻质隔爆材料的实验研究   总被引:4,自引:0,他引:4  
对数十种材料的隔爆性能进行了研究。用上下法分别求出不同材料的雷管径向殉爆以及轴向殉爆的半爆距离L50。针对材料密度小,隔爆效果好的要求,定义了一个既考虑材料密度又考虑其隔爆性能的优化参数,并以此作为判据,对实验材料进行了优选  相似文献   
903.
ABSTRACT: Environmental protection dictates that effluents of desired quality should be dischargd from dredged material confinement facilities. In general, this can be accomplished by supplementing the solid-liquid separation obtained by simple sedimentation with appropriate filter systems which provide additional clarification. A methodology to estimate the sedimentation required in a disposal area was developed on the basis of classical sedimentation theories and compared favorably with field data. A procedure was then advanced and documented whereby effluents from dredged material confinement facilities can be successfully modeled for laboratory filtration tests. For these purposes inorganic suspended solids can be simulted reasonably well by adjusting the concentration of commercially available clays, and fresh or saline water environments can be simulated satisfactorily by tap water or sodium chloride solutions, respectively.  相似文献   
904.
焚烧炉医疗垃圾输送装置是专门为医疗垃圾焚烧炉研究设计的配套上料设备.具有体积小,操作方便,实现全自动控制等优点.成功地替代了人工上料方式,有效避免了操作者与物料的直接接触.上料速度均匀可调,有利于保证和提高焚烧效率.清洗、消毒方便,符合有关规范要求.  相似文献   
905.
焚烧炉医疗垃圾输送装置是专门为医疗垃圾焚烧炉研究设计的配套上料设备。具有体积小,操作方便,实现全自动控制等优点。成功地替代了人工上料方式,有效避免了操作者与物料的直接接触。上料速度均匀可调,有利于保证和提高焚烧效率。清洗、消毒方便,符合有关规范要求。  相似文献   
906.
绿色高分子材料及其发展展望   总被引:2,自引:0,他引:2  
介绍了环境友好的绿色高分子材料的重要性,列举了几种可降解高分子材料的类型及其特性,从可降解塑料的研制方面谈及充分、合理地利用资源,同时展望绿色高分子材料的应用前景。  相似文献   
907.
Structural insulated panels (SIPs) have significant environmental and energy advantages. However, the tight structure that results may cause degraded indoor air quality and the potential release of volatile organic compounds (VOCs) from these layered materials must be considered. A physically based model for predicting VOC emissions from multi-layer materials is described. Fugacity is used to eliminate the concentration discontinuities at the interface between layers. This avoids an obstacle associated with numerically simulating mass transfer in composite materials. The numerical model is verified for a double-layer system by comparing predicted concentrations to those obtained with a previously published analytical model. In addition, hexanal emissions from multi-layer SIPs are simulated to demonstrate the usefulness of the fugacity approach. Finally, the multi-layer model is used to investigate the impact that clay/polyurethane nanocomposite diffusion barriers can have on VOC emissions. Indoor gas-phase concentrations can be greatly reduced with a barrier layer on the surface, thereby minimizing the environmental impact of SIPs.  相似文献   
908.
Background, Aim and Scope At present, large-scale paper manufacture involves delignification and bleaching by elemental chlorine free (ECF) or totally chlorine free (TCF) processes. The wastewater is purified by secondary treatment (mechanical, chemical and biological) which removes most of the toxic substances from the discharge. However, we found residual toxicity in the high molecular (> 1000 D) matter (HMWM) of the discharge by test of the RET (reverse electronic transfer) inhibition. This fraction consists mainly of polydisperse lignin (LIG) and carbohydrate (CH) macromolecules. Structural units in these molecules are studied by pyrolysis gas chromatography / mass spectrometry (Pyr-GC/MS). In the present work, our aim was to find out those structural units which could explain the RET toxicity of LIG or CH molecules. We compared statistically RET toxicity values of the HMWM samples from treated wastewaters of pilot pulping experiments and intensity variation of the pyrolysis product gas chromatograms of these samples. This application is a novel study procedure. Methods Pyrolysis products (Py-GC/MS results) and inhibition of RET (reverse electronic transport toxicity) as TU50 and TU20 of HMWM (High Molecular Weight Material; Mw > 1000 D) were compared by multivariate statistics. The samples were from laboratory pilot stages of TCF (Totally Chlorine Free) and ECF (Elemental Chlorine Free) manufacture of softwood pulp. Py-GC/MS was done without and with addition of TMAH (Tetra Methyl Ammonium Hydroxide). The name and structure of each abundant fragment compound was identified from its retention time and mass spectrum compared to authentic reference compounds or literature. Four sets of Toxicity Units (TUs) and GC peak areas of the pyrolysis fragments were obtained. The data were normalized by division with LIG (lignin content of each sample). TU values were dependent and the fragment values independent (explanatory) variables in statistical treatments by SPSS system. Separate analyses of correlations, principal components (PCA) and stepwise multiple linear regression (SMLR) were performed from the four sample sets TCF and ECF with and without TMAH. Results and Discussion From the CH fragments, 2-furfural in TCF, and from the LIG fragments, styrene in ECF showed the highest probabilities to originate from source structures of toxicity. Other possible compounds in concern were indicated to be CH fragment 2-methyl-2-cyclopenten-1-one in ECF and LIG fragments 2-methoxy-4-methylphenol, 4,5-dimethoxy-2-methylphenol and 2-methylphenol in TCF.  相似文献   
909.
研究了混凝土生态膜污水处理工艺的循环挂膜过程.综合考察了混凝土膜片表面生物膜的生长变化情况、细菌数量及其微型动物的组成演化.生物膜成熟以后,投加实际生活污水连续运行:COD的平均去除率为76.0%;BOD5平均去除率为94.9%,出水均小于8.00 mg/L;NH3-N的去处理效果明显,第5周达到54.1%,出水可达到广东省一级排放标准中的相关规定.  相似文献   
910.
以新鲜鸡、牛粪为材料 ,研究了不同堆制方法对粪便发酵温度与脱水率的影响。结果表明 :牛粪中添加 10 0g·kg-1的稻草在堆制开始 5d ,温度较高 ,但第 3 0天时脱水率反而低于添加 5 0g·kg-1稻草的处理 ;覆盖薄膜降低了粪便脱水速率 ;分批添加物料方法发酵 12d ,堆肥含水量由开始的 5 2 0g·kg-1下降到 5 0 3g·kg-1,而同期 1次添加物料方法发酵 ,堆肥水分含量为 5 5 4g·kg-1。  相似文献   
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