全文获取类型
收费全文 | 8256篇 |
免费 | 774篇 |
国内免费 | 2770篇 |
专业分类
安全科学 | 413篇 |
废物处理 | 128篇 |
环保管理 | 624篇 |
综合类 | 6484篇 |
基础理论 | 2601篇 |
污染及防治 | 629篇 |
评价与监测 | 648篇 |
社会与环境 | 188篇 |
灾害及防治 | 85篇 |
出版年
2024年 | 149篇 |
2023年 | 453篇 |
2022年 | 499篇 |
2021年 | 622篇 |
2020年 | 438篇 |
2019年 | 485篇 |
2018年 | 288篇 |
2017年 | 294篇 |
2016年 | 456篇 |
2015年 | 485篇 |
2014年 | 813篇 |
2013年 | 525篇 |
2012年 | 551篇 |
2011年 | 557篇 |
2010年 | 481篇 |
2009年 | 534篇 |
2008年 | 543篇 |
2007年 | 462篇 |
2006年 | 374篇 |
2005年 | 316篇 |
2004年 | 255篇 |
2003年 | 265篇 |
2002年 | 243篇 |
2001年 | 196篇 |
2000年 | 188篇 |
1999年 | 125篇 |
1998年 | 152篇 |
1997年 | 127篇 |
1996年 | 148篇 |
1995年 | 139篇 |
1994年 | 111篇 |
1993年 | 113篇 |
1992年 | 96篇 |
1991年 | 104篇 |
1990年 | 105篇 |
1989年 | 81篇 |
1988年 | 7篇 |
1987年 | 14篇 |
1986年 | 5篇 |
1979年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
321.
Jun Bai Xiuhong Yang Ruiying Du Yanmei Chen Shizhong Wang Rongliang Qiu 《环境科学学报(英文版)》2014,26(10):2056-2064
Mechanisms of soil Pb immobilization by Bacillus subtilis DBM, a bacterial strain isolated from a heavy-metal-contaminated soil, were investigated. Adsorption and desorption experiments with living bacterial cells as well as dead cells revealed that both extracellular adsorption and intracellular accumulation were involved in the Pb2+removal from the liquid phase. Of the sequestered Pb(II), 8.5% was held by physical entrapment within the cell wall, 43.3% was held by ion-exchange, 9.7% was complexed with cell surface functional groups or precipitated on the cell surface, and 38.5% was intracellularly accumulated.Complexation of Pb2+with carboxyl, hydroxyl, carbonyl, amido, and phosphate groups was demonstrated by Fourier transform infrared spectroscopic analysis. Precipitates of Pb5(PO4)3OH, Pb5(PO4)3Cl and Pb10(PO4)6(OH)2that formed on the cell surface during the biosorption process were identified by X-ray diffraction analysis. Transmission electron microscopy–energy dispersive spectroscopic analysis confirmed the presence of the Pb(II)precipitates and that Pb(II) could be sequestered both extracellularly and intracellularly.Incubation with B. subtilis DBM significantly decreased the amount of the weak-acid-soluble Pb fraction in a heavy-metal-contaminated soil, resulting in a reduction in Pb bioavailability, but increased the amount of its organic-matter-bound fraction by 71%. The ability of B.subtilis DBM to reduce the bioavailability of soil Pb makes it potentially useful for bacteria-assisted phytostabilization of multi-heavy-metal-contaminated soil. 相似文献
322.
Arbuscular mycorrhizal fungi(AMF) are important components of soil microbial communities,and play important role in plant growth. However, the effects of AMF phylogenetic groups(Glomeraceae and non-Glomeraceae) on host plant under various heavy metal levels are not clear. Here we conducted a meta-analysis to compare symbiotic relationship between AMF phylogenetic groups(Glomeraceae and non-Glomeraceae) and host plant functional groups(herbs vs. trees, and non-legumes vs. legumes) at three heavy metal levels. In the meta-analysis, we calculate the effect size(ln(RR)) by taking the natural logarithm of the response ratio of inoculated to non-inoculated shoot biomass from each study. We found that the effect size of Glomeraceae increased, but the effect size of non-Glomeraceae decreased under high level of heavy metal compared to low level. According to the effect size, both Glomeraceae and non-Glomeraceae promoted host plant growth, but had different effects under various heavy metal levels. Glomeraceae provided more benefit to host plants than non-Glomeraceae did under heavy metal condition, while non-Glomeraceae provided more benefit to host plants than Glomeraceae did under no heavy metal. AMF phylogenetic groups also differed in promoting plant functional groups under various heavy metal levels.Interacting with Glomeraceae, herbs and legumes grew better than trees and non-legumes did under high heavy metal level, while trees and legumes grew better than herbs and non-legumes did under medium heavy metal level. Interacting with non-Glomeraceae, herbs and legumes grew better than trees and non-legumes did under no heavy metal. We suggested that the combination of legume with Glomeraceae could be a useful way in the remediation of heavy metal polluted environment. 相似文献
323.
Evi Kurniati Novi Arfarit Tsuyoshi Imai Takaya Higuchi Ariyo Kanno Koichi Yamamoto Masahiko Sekine 《环境科学学报(英文版)》2014,26(6):1223-1231
The use of filamentous fungi in bioremediation of heavy metal contamination has been developed recently. This research aims to observe the capability of filamentous fungi isolated from forest soil for bioremediation of mercury contamination in a substrate. Six fungal strains were selected based on their capability to grow in 25 mg/L Hg2+-contaminated potato dextrose agar plates. Fungal strain KRP1 showed the highest ratio of growth diameter, 0.831, thus was chosen for further observation.Identification based on colony and cell morphology carried out by 18S rRNA analysis gave a 98%match to Aspergillus flavus strain KRP1. The fungal characteristics in mercury(Ⅱ) contamination such as range of optimum pH, optimum temperature and tolerance level were 5.5–7 and 25–35℃ and 100 mg/L respectively. The concentration of mercury in the media affected fungal growth during lag phases. The capability of the fungal strain to remove the mercury(Ⅱ) contaminant was evaluated in 100 mL sterile 10 mg/L Hg2+-contaminated potato dextrose broth media in 250 mL Erlenmeyer flasks inoculated with 108spore/mL fungal spore suspension and incubation at 30℃ for 7 days. The mercury(Ⅱ) utilization was observed for flasks shaken in a 130 r/min orbital shaker(shaken) and nonshaken flasks(static) treatments. Flasks containing contaminated media with no fungal spores were also provided as control. All treatments were done in triplicate. The strain was able to remove 97.50%and 98.73% mercury from shaken and static systems respectively. A. flavus strain KRP1 seems to have potential use in bioremediation of aqueous substrates containing mercury(Ⅱ) through a biosorption mechanism. 相似文献
324.
Yuguang Zhang Jing Cong Hui Lu Guangliang Li Yuanyuan Qu Xiujiang Su Jizhong Zhou Diqiang Li 《环境科学学报(英文版)》2014,26(8):1717-1724
Acidobacteria is one of the most dominant and abundant phyla in soil,and was believed to have a wide range of metabolic and genetic functions. Relatively little is known about its community structure and elevational diversity patterns. We selected four elevation gradients from 1000 to 2800 m with typical vegetation types of the northern slope of Shennongjia Mountain in central China. The vegetation types were evergreen broadleaved forest,deciduous broadleaved forest,coniferous forest and sub-alpine shrubs. We analyzed the soil acidobacterial community composition,elevational patterns and the relationship between Acidobacteria subdivisions and soil enzyme activities by using the 16 S rRNA meta-sequencing technique and multivariate statistical analysis. The result found that 19 known subdivisions as well as an unclassified phylotype were presented in these forest sites,and Subdivision 6 has the highest number of detectable operational taxonomic units(OTUs). A significant single peak distribution pattern(P 0.05) between the OTU number and the elevation was observed. The Jaccard and Bray–Curtis index analysis showed that the soil Acidobacteria compositional similarity significantly decreased(P 0.01) with the increase in elevation distance. Mantel test analysis showed the most of the soil Acidobacteria subdivisions had the significant relationship(P 0.01) with different soil enzymes. Therefore,soil Acidobacteria may be involved in different ecosystem functions in global elemental cycles. Partial Mantel tests and CCA analysis showed that soil pH,soil temperature and plant diversity may be the key factors in shaping the soil Acidobacterial community structure. 相似文献
325.
中宜环境医院:重构环保产业发展新模式 总被引:1,自引:0,他引:1
《世界环境》2014,(6):54-58
<正>近年来,雾霾、水污染、有毒土壤等词眼,频频走入人们的视线,环境问题已成为社会大众关注的焦点。"人生病了,需要进医院治疗,需要医生、医疗器械和药剂。环境生病了,同样也需要治理。"中国宜兴环保科技工业园管委会主任朱旭峰生动形象地诠释了"环境医院"的诞生背景。在宏观经济领域,危机之后缓慢而痛苦的恢复过程被称为"新常态"。当前的环保行业,也表现出了从"无序"向"有 相似文献
326.
为了考察珠江三角洲地区大气和土壤中多氯联苯(PCBs)残留现状,于2012年在珠江三角洲地区采集了空气和土壤样品,并利用GC-MS进行PCBs分析测定。结果表明,大气中Σ24PCBs的总浓度为240~2 258 pg/m3,平均为1 243 pg/m3,且PCBs主要存在于气相中,占24种PCBs总浓度的90%以上,单体分布主要以三氯~五氯联苯为主。自2001年以来珠江三角洲地区大气中PCBs浓度有小幅波动,说明部分地区有PCBs源释放的可能。土壤中24种PCBs的总浓度为ND~20.68 ng/g,平均为3.77 ng/g。三氯联苯是土壤中PCBs的主要同类物,平均占土壤中24种PCBs总浓度的45%,其次是四氯联苯,平均占19%。部分地点低氯代PCBs比例下降,高氯代比例升高。 相似文献
327.
通过对北京和天津地区18条土壤剖面样品中PAHs的分析检测及PAHs的土柱淋滤实验模拟研究,得出了部分反映PAHs污染源的分子标志物参数在土壤剖面(或淋滤土柱)上的纵向变化特征,分析了PAHs化合物的纵向迁移作用对这些参数的影响,讨论了部分用于识别土壤中PAHs污染源的分子标志物参数的有效性。结果表明:在土壤剖面0~50 cm范围内,An/Ph,MPI1,MP/P值均有随深度增加而逐渐降低的趋势,在深层(>50 cm)不同剖面之间这些参数值差别不大;Fl/Py随深度增大呈现一定的波动性,但总体波动范围较小,且在0~40 cm变化不大;C0/(C0+C1)P/A和C0/(C0+C1)F/P值变化较为复杂。土柱淋滤实验表明,在0~50 cm范围内,部分PAHs污染源识别参数(An/178、MPI1、MP/P、C0/(C0+C1)F/P和C0/(C0+C1)P/A等)随深度的变化趋势与自然土壤剖面中的变化趋势基本一致,在深层50~100 cm范围内,这些参数值的大小逐渐与原土中的接近。表明淋滤作用(迁移过程)对表层土及土壤剖面浅部(50 cm范围内)部分PAHs污染源参数值的大小有不同程度的影响,运用PAHs污染源识别参数时,这些参数的有效性应引起足够的注意;而剖面深部(>50 cm)PAHs参数值受表层污染物组成的影响较小,其大小主要反映原土中化合物组成及成因。不同剖面受淋滤作用影响的范围存在一定的差别,这主要取决于土壤中TOC的分布特征。 相似文献
328.
汞污染农田土壤低温热解处理性能研究 总被引:2,自引:0,他引:2
选取贵州清镇地区汞污染农田土壤作为低温热解修复试验对象,研究处理温度、处理时间以及土壤含水率对低温热解法去除土壤汞效率的影响。同时采用连续浸提法对土样中7种形态的汞进行提取,分析热解升温过程中各形态汞的变化状况。结果表明:(1)处理温度越高,汞去除效率越大。当温度为350℃时,去除率达到90%以上。(2)处理时间越长,汞的去除率越高。处理持续时间为90min时,去除率达到90%。(3)土壤含水率越高,汞去除率越低。当风干时间10 d,土壤含水率13.8%时为处理土壤最佳条件。(4)7种形态的汞随温度升高均下降显著,当温度达到350℃时,处理后土样中水溶态和交换态已完全去除,其他形态的去除率也均达到90%以上,土样中最终以残渣态汞为主,环境风险小。 相似文献
329.
选择四川攀枝花地区广泛分布的3种土壤,研究五价钒[V(Ⅴ)]与四价钒[V(Ⅳ)]在土壤中的吸附-解吸行为。分别运用Langmuir模型和Freundlich模型对V在黄棕壤、紫色土和水稻土中的等温吸附线进行拟合,计算出这2种价态的V在各土壤中的最大吸附量,比较不同土壤对不同价态V的吸附能力,同时分别分析3种土壤吸附平衡液与解吸液pH的变化。结果表明:(1)2种价态的V在3种土壤中的等温吸附线与两模型均基本吻合;(2)3种土壤对2种价态的V的吸附能力大小顺序一致,依次为:黄棕壤>水稻土>紫色土;(3)3种土壤对V(Ⅳ)的最大吸附量基本一致,但紫色土与水稻土对V(Ⅴ)的最大吸附量高于黄棕壤;(4)V(Ⅳ)在3种土壤中的解吸率高于V(Ⅴ),最高可达48.93%;(5)V(Ⅴ)的吸附平衡液与解吸液pH均随V浓度增加呈上升趋势,而V(Ⅳ)的吸附平衡液与解吸液pH均随V(Ⅳ)浓度增加呈下降趋势,且3种土壤的吸附平衡液pH变化幅度较解吸液大。 相似文献
330.
有机氯农药在农田土壤中的吸附解吸特征 总被引:2,自引:0,他引:2
选取3种不同深度的农田土壤作为吸附剂,采用批量实验方法,研究了有机氯农药p,p’-DDD和γ-HCH在等温条件下的吸附解吸行为。结果表明,p,p’-DDD和γ-HCH的吸附解吸曲线均可用Freundlich模型较好拟合,并且在表层土壤中表现为线性,而在深部土壤中表现为非线性,表明深部土壤的组成可能更加复杂和不均匀。3种土壤对p,p’-DDD的吸附容量参数Kf值与总有机碳(TOC)含量大小关系一致,而γ-HCH的吸附Kf值却与DOM含量显著正相关。p,p’-DDD和γ-HCH在所有样品中的解吸均有不同程度的滞后现象,其中p,p’-DDD的解吸主要受土壤中有机质含量的影响,TOC含量越低滞后性越不明显,而γ-HCH的解吸滞后性比较复杂。 相似文献