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231.
Characterizing water quality and identifying potential pollution sources could greatly improve our knowledge about human impacts on the river ecosystem. In this study, fuzzy comprehensive assessment (FCA), pollution index (PI), principal component analysis (PCA), and absolute principal component score–multiple linear regression (APCS–MLR) were combined to obtain a deeper understanding of temporal–spatial characterization and sources of water pollution with a case study of the Jinjiang River, China. Measurement data were obtained with 17 water quality variables from 20 sampling sites in the December 2010 (withered water period) and June 2011 (high flow period). FCA and PI were used to comprehensively estimate the water quality variables and compare temporal–spatial variations, respectively. Rotated PCA and receptor model (APCS–MLR) revealed potential pollution sources and their corresponding contributions. Application results showed that comprehensive application of various multivariate methods were effective for water quality assessment and management. In the withered water period, most sampling sites were assessed as low or moderate pollution with characteristics pollutants of permanganate index and total nitrogen (TN), whereas 90 % sites were classified as high pollution in the high flow period with higher TN and total phosphorus. Agricultural non-point sources, industrial wastewater discharge, and domestic sewage were identified as major pollution sources. Apportionment results revealed that most variables were complicatedly influenced by industrial wastewater discharge and agricultural activities in withered water period and primarily dominated by agricultural runoff in high flow period.  相似文献   
232.
以编制区域循环经济发展规划为主线,概述了我国循环经济发展的总体趋势和资源型城市经济转型试点的接续产业发展规划;探索性地提出制定循环经济产业基地集聚区建设规划的工作思路;强调发挥政府规划和投融资政策的引导作用,以及建立产业政策体系和激励机制的必要性。  相似文献   
233.
Pan D  Teng L  Cui F  Zeng Z  Bravery BD  Zhang Q  Song Y 《Ambio》2011,40(1):60-67
As human populations expand and nonhuman animals decline, understanding the interactions between people and wildlife is essential. For endangered species, appreciating the effect of human disturbance can be important for their conservation. However, a human disturbance angle is often absent from ecological research, despite growing evidence of the negative impact of nonfatal human interference. Here, we monitored Hainan Eld’s deer living within a reserve and translocated animals living amongst villagers. We show that translocated deer deviated from a crepuscular activity pattern and became increasingly nocturnal, and most active when villagers were not. It appears that translocated deer adapted over time to human disturbance and this pattern is similar to that of other species during periods of hunting. People do not pose an actual threat to Eld’s deer, but their presence triggered a response akin to predator avoidance and may be interfering with broader aspects of their biology and conservation.  相似文献   
234.
Residual levels and enantiomeric signatures of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) in surface sediments from Xiangshan Bay, East China Sea were investigated. The concentrations of ∑HCHs (sums of α-, β-, γ-, and δ-HCH) and ∑DDTs (sums of p, p'-DDT, p, p'-DDD,p, p'-DDE, o, p'-DDT, and o, p'-DDD) ranged from 0.14 to 0.67 ng g?1 and 0.61 to 22.38 ng g?1, respectively. A slight potential health risk to the organism was then indicated for the residual levels of DDTs according to the ERL/ERM guidelines. Moreover, the predominant β-HCH implied that the technical HCH contamination was mainly due to the historical usage. But the high ratio of DDT/∑DDTs depicted a cocktail input pattern of fresh and weathered DDTs. The enantiomeric fractions (EFs) of α-HCH, o, p'-DDT, and o, p'-DDD were also determined. The degradation of α-HCH was enantioselective in all sediments samples, resulting in an enrichment of (-)-enantiomers. However, the racemic residues of o, p'-DDT and o, p'-DDD were observed in all sediments samples.  相似文献   
235.
BACKGROUND: A climate-controlled pot experiment was conducted to investigate the effects of planting alfalfa and applying organic fertilizer on the dissipation of benzo[a]pyrene from an aged contaminated agricultural soil. RESULTS: Short-term planting of alfalfa inhibited the dissipation of benzo[a]pyrene from the soil by 8.9%, and organic fertilizer enhanced benzo[a]pyrene removal from the soil by 11.6% compared with the unplanted and unfertilized treatments, respectively. No significant interaction was observed between alfalfa and organic fertilizer on benzo[a]pyrene dissipation. Sterilization completely inhibited the removal of benzo[a]pyrene from the soil indicating that its degradation by indigenous microorganisms may have been the main mechanism of dissipation. Furthermore, significant positive relationships were observed between benzo[a]pyrene removal and the contents of soil ammonium nitrogen, nitrate nitrogen, and total mineral nitrogen at the end of the experiment, suggesting that competition between plants and microorganisms for nitrogen may have inhibited benzo[a]pyrene dissipation in the rhizosphere of alfalfa and the addition of organic fertilizer may facilitate microbial degradation of benzo[a]pyrene in the soil.  相似文献   
236.
采用自制的单极性复合型三维阳极作为第三维电极对含氟水进行动态电促吸附实验,通过研究不同填充床高度、阴阳极板间距、隔膜材料对电促吸附除氟效果的影响,确定反应器的最佳结构参数为:填充床高度20 cm、阴阳极板间距4 cm、隔膜为nafion117膜。工作电压、进水pH、进水流速、共存物质对氟离子去除效果的影响结果表明:在一定范围内增大工作电压,降低进水pH或进水流速均可提高除氟效果。相应的最佳操作条件为:工作电压7 V、进水流速4 mL/min、酸性pH;腐殖酸和碳酸根离子的存在会对氟离子去除产生较强抑制作用,低浓度的氯离子可促进氟离子的电促吸附。扫描电镜(SEM)-电子能谱(EDX)的表征结果显示三维颗粒电极的表面及孔隙内部均可吸附氟离子,且电吸附后并未出现电极腐蚀现象。  相似文献   
237.
刘腾  邱兆富  杨骥  曹礼梅  张巍 《化工环保》2015,35(2):159-164
根据我国每年的石油消费量估算了当年的废炼油催化剂产生量,预测2015年我国废炼油催化剂的产生量将达到2.07×105 t。介绍了废炼油催化剂的主要成分、含量与危害,分别论述了废流化催化裂化催化剂、废催化加氢催化剂和废催化重整催化剂的处理和利用方法,指出废炼油催化剂的再生及资源化和无害化应是未来的重点研究方向。  相似文献   
238.
Phthalic acid esters (PAEs) pollution in agricultural soils caused by widely employed plastic products is becoming more and more widespread in China. PAEs polluted soil can lead to phytotoxicity in higher plants and potential health risks to human being. We evaluated the individual toxicity of di-n-butyl phthalate (DnBP) and bis(2-ethylhexyl) phthalate (DEHP), two representative PAEs, to sown rape (Brassica chinensis L.) seeds within 72 h (as germination stage) and seedlings after germination for 14 days by monitoring responses and trends of different biological parameters. No significant effects of six concentrations of PAE ranging from 0 (not treated/NT) to 500 mg?kg?1 on germination rate in soil were observed. However, root length, shoot length, and biomass (fresh weight) were inhibited by both pollutants (except root length and biomass under DEHP). Stimulatory effects of both target pollutants on malondialdehyde (MDA) content, superoxide dismutase (SODase) activity, ascorbate peroxidase (APXase) content, and polyphenoloxidase (PPOase) activity in shoots and roots (SODase activity in shoots excluded) were in the same trend with the promotion of proline (Pro) but differed with acetylcholinesterase activity (except in shoots under DnBP) for analyzed samples treated for 72 h and 14 days. Responses of representative storage compounds free amino acids (FAA) and total soluble sugar (TSS) under both PAEs were raised. Sensitivity of APXase and Pro in roots demonstrates their possibility in estimation of PAE phytotoxicity and the higher toxicity of DnBP, which has also been approved by the morphological photos of seedlings at day 14. Higher sensitivity of the roots was also observed. The recommended soil allowable concentration is 5 mg DnBP?kg?1 soil for the development of rape. We still need to know the phytotoxicity of DEHP at whole seedling stage for both the growing and development; on the other hand, soil criteria for PAE compounds are urgently required in China.  相似文献   
239.
在野外模拟降雨条件下,开展了晋江西溪流域茶园和裸地的径流产沙及氮磷养分流失过程对比实验,研究结果表明,在相同降雨强度下,3种下垫面径流和产沙量顺序均为:裸地>2年茶园>4年茶园,径流量与产沙量之间呈显著正相关.对地表径流水相而言,2年茶园、4年茶园和裸地的TN流失量分别为:461.29、129.38和107.86 mg/m2;NO3-N流失量分别为:286.42、98.58和103.00 mg/m2,均占TN流失量的60%以上;NH4-N流失量分别为:48.67、16.19和4.42 mg/m2;Tp流失量分别为:34.71、16.47和23.88 mg/m2.对径流泥沙相而言,2年茶园、4年茶园和裸地的TN流失量分别为:379.28、44.81和747.16 mg/m2,占流失总量的比重在25.72%~87.93%之间;TP流失量分别为:27.94、4.17和58.85 mg/m2,占流失总量的比重在53.42% ~68.36%之间.茶园的N、P主要随径流流失,而裸地以泥沙迁移为主.这说明茶叶种植具有一定的水土保持效应,且种植年限较长的茶园可显著减少随径流泥沙进入水体中的N、P元素.  相似文献   
240.
二氧化钛纳米管被用于光催化氧化水体中的百草枯,对光催化反应条件、常见Fe3+离子的干扰情况和百草枯光催化降解动力学规律进行了研究。结果表明,浓度为25 mg/L的百草枯溶液,在二氧化钛纳米管(TNT)1.0 g/L,H2O20.5 mL/50 mL,pH=5.0的最优光催化氧化条件下,经过30 min反应可以被100%从水体中去除,表现出非常高的光催化降解效率;动力学方程拟合表明,百草枯光催化氧化反应符合拟一级动力学规律,动力学方程为ln(C0/C)=1.0267t-0.1282,反应速率常数K为1.0267 h-1;双氧水存在时常见的Fe3+能够进一步提高百草枯光催化降解率;该光催化反应体系对低浓度百草枯废水有很好的处理效果,预示着光催化氧化技术适合地表或地下水体中百草枯的去除。  相似文献   
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