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941.
β-萘磺酸钠生产废水的处理   总被引:9,自引:0,他引:9  
先采用液膜分离技术对β-萘磺酸钠生产废水进行处理,回收其中的β-萘磺酸钠,然后用H2O2-Fe2+催化氧化法进行深度处理,取得很好的效果。废水COD和色度去除率分别可达99.54%和94.14%,处理后的废水达到排放标准  相似文献   
942.
Ecological footprint has been given much attention and widely praised as an effective heuristic and pedagogic device for presenting current total human resource use in a way that communicates easily to almost everyone since 1996 when Wackernagel and Rees proposed it as a sustainable development indicator. Ecological footprint has been improving on its calculation and still can be a benchmark to measure sustainable development although there are still ongoing debates about specific methods for calculating the ecological footprint.This paper calculates the ecological footprint of Shandong Province, China with the methodology developed by Wackernagel and analyzes the current situation of sustainable development in Shandong.  相似文献   
943.
Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this paper, a full-scale study of chlorine dioxide preoxidation cooperating with routine clarification process for Cyclops removal was conducted in a waterworks. The experimental results were compared with that of the existing prechlorination process in several aspects: including the Cyclops removal efficiencies of water samples taken from the outlets of sedimentation tank and sand filter and the security of drinking water and so on. The results showed that chlorine dioxide might be more effective to inactivate Cyclops than chlorine and Cyclops could be thoroughly removed from water by pre-dosing chlorine dioxide process. The GC-MS examination and Ames test further showed that the sort and amount of organic substance in the treated water by chlorine dioxide preoxidation were evidently less than that of prechlorination and the mutagenicity of drinking water treated by pre-dosing chlorine dioxide was substantially reduced compared with prechlorination.  相似文献   
944.
Cadmium and lead have been identified as very toxic metals, which are widely present in the environment due to natural and anthropogenic emissions. Many studies have shown that the food chain is the main pathway of cadmium and lead transfer from the environment to humans. It is well documented that many factors will affect their transfer through food chains. Previous investigations on heavy metals were mostly concentrated on one contaminant in isolation. However, in real environments, exposure to mixtures of metals is ubiquitous such that cadmium pollution is invariably being associated with lead and zinc, etc. This study focuses on the contamination and health effects of the metal mixtures. For this purpose, a dietary survey was taken for 3 groups in Nanning in October 2002. Samples of soils, plants (vegetables), urine and blood of humans were measured for Cd, Fe, Cu, Zn, Ca and Pb, in addition, the urinary indicators of renal dysfunction Albumin (ALB), N-acetyl-beta-D-glucosaminidase (NAG), Beta-2-microglobulin (beta2-MG) and Retinol-binding protein (RBP) in urine were also measured. Results showed that soil contamination with metal mixtures had caused significant renal dysfunction of the local residents living in the contaminated area, and the dose-response curve was somewhat altered by the mixed contamination of Cd and Pb as well as the intake of other minerals. The importance of mixtures of metal contamination and human health are also discussed in this paper.  相似文献   
945.
开展长江经济带生态状况变化研究对于评估不同类型主体功能分区的国土开发强度,提升生态安全保障能力具有重要意义。通过生态系统宏观结构、植被覆盖度、植被净初级生产力分析评价了2010~2015年长江经济带不同主体功能分区的生态状况变化特征。结果表明:优化开发区、重点开发区、农产品主产区和重点生态功能区内聚落生态系统面积分别占该类主体功能区国土面积的2525%、655%、370%和040%,总体上体现了国土开发按照不同主体功能布局的梯级特征。重点生态功能区的城镇用地和其他建设用地年变化率高于优化开发区和重点开发区,不符合其“限制开发”的功能定位,需加强空间管控,增强生态产品供给能力。长江经济带平均植被覆盖度、净初级生产力总体呈现好转态势。植被覆盖度基本稳定、转好、转差的面积比例分别为6043%、2520%和1437%;植被净初级生产力基本稳定、转好、转差的面积比例分别为4982%、4536%和482% 关键词: 主体功能区;植被覆盖度;净初级生产力;长江经济带  相似文献   
946.
研究了土壤干旱胁迫对Larrea tridentata叶片10种营养元素含量的影响.结果表明:N、P、K、Ca、Mg含量在土壤干旱胁迫下的变化趋势基本相同,都是在轻度水分胁迫时略有下降,随着土壤水分胁迫的加重,含量逐渐增加,只有P含量在重度水分胁迫(土壤水势为-2.415 MPa)时有所下降;在土壤水势超过了萎蔫系数后,L.tridentata的各大量营养元素含量仍能维持在较高水平有助于增强其抗旱性;L.tridentata叶片微量元素(Fe、B、Mn、Cu、Mo)含量对土壤干旱胁迫的反映不敏感,各微量营养元素的含量在土壤干旱胁迫时与正常土壤水分状态时没有显著差异;总的来讲,在土壤水分胁迫状况下,L.tridentata能通过对自身营养元素调节的方式来提高自身的抗旱性,表现出较强的抗旱性.  相似文献   
947.
从首钢及武钢焦化废水处理系统中分离筛选出10 株高效喹啉降解细菌,16S rRNA 鉴定表明它们分别属于假单胞菌及丛毛单胞菌2个属.对这些高效降解菌进行了降解基因片断的PCR 扩增,发现所有假单胞菌属的喹啉降解菌均含有编码转化喹啉为2-羟基喹啉和2,8-二羟基喹啉的基因片断.16S rRNA 与降解基因系统发育树的对比分析,表明细菌进化过程中可能存在的基因突变和水平基因转移现象.根据假单胞菌属的喹啉降解菌降解基因的特异性,利用荧光原位杂交技术对该菌在首钢活性污泥中的种群空间分布进行了检测.另外,对高效降解菌的质粒分布做了初步的探讨,发现喹啉降解基因可能主要编码在细菌的染色体上.  相似文献   
948.
Reservoirs are regarded as hotspots of nitrogen transformation and potential sources of nitrous oxide(N2O). However, it remains unclear how the hydrological conditions due to dam construction control the processes of nitrogen transformation in reservoir waters. To address this issue, we examined the spatial-temporal characteristics of nitrate concentrations, δ15N-NO3-, δ18O-NO3-, δ18O-H2O, relative...  相似文献   
949.
Marine oil spills affect the environment, economy, and quality of life for coastal inhabitants. This article presents a method of X-band marine radar oil-spill identification by considering the marine radar images of the 2010 Dalian 7-16 accident. The Prewitt operator was improved and a linear interpolation was proposed to suppress co-channel interferences. In addition, a model of a gray-intensity-correcting matrix is proposed to smooth a whole image, thus displaying the oil film more intuitively. Furthermore, a contrast-limited adaptive histogram equalization method was used to increase the contrast inside and outside the oil film. Moreover, the local adaptive thresholding method was improved to segment the oil spills. The results show that the proposed method is an improvement on similar previous approaches for this task when employing X-band marine radar images. The proposed method can provide technical and theoretical bases for emergency response, damage assessment, and liability identification of oil spills.  相似文献   
950.
采用混凝沉淀-双层滤料过滤-陶瓷膜过滤组合工艺去除丙烯酸丁酯废水中浊度物质。结果表明,废水pH值、混凝药剂投加量、混凝沉淀水力条件不仅对丙烯酸丁酯废水混凝沉淀出水和双层滤料过滤单元出水浊度具有重要影响,而且对后续陶瓷膜过滤单元膜污染均具有重要影响。双层滤料过滤出水浊度与陶瓷膜污染阻力具有明显的正相关关系,双层滤料过滤出水浊度越高,陶瓷膜污染阻力越大。废水pH在7.0~10.0范围内、混凝药剂PAC或PAM投加过量、废水流量过高都会造成双层滤料过滤出水浊度偏高,导致陶瓷膜污染严重。  相似文献   
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