全文获取类型
收费全文 | 1187篇 |
免费 | 8篇 |
国内免费 | 28篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 57篇 |
环保管理 | 151篇 |
综合类 | 100篇 |
基础理论 | 203篇 |
污染及防治 | 420篇 |
评价与监测 | 215篇 |
社会与环境 | 64篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 34篇 |
2022年 | 75篇 |
2021年 | 62篇 |
2020年 | 12篇 |
2019年 | 27篇 |
2018年 | 39篇 |
2017年 | 34篇 |
2016年 | 54篇 |
2015年 | 28篇 |
2014年 | 50篇 |
2013年 | 155篇 |
2012年 | 60篇 |
2011年 | 63篇 |
2010年 | 50篇 |
2009年 | 47篇 |
2008年 | 65篇 |
2007年 | 44篇 |
2006年 | 43篇 |
2005年 | 34篇 |
2004年 | 33篇 |
2003年 | 29篇 |
2002年 | 21篇 |
2001年 | 17篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1982年 | 5篇 |
1978年 | 5篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1972年 | 3篇 |
1969年 | 5篇 |
1968年 | 4篇 |
1965年 | 3篇 |
1959年 | 2篇 |
1957年 | 3篇 |
1956年 | 2篇 |
排序方式: 共有1223条查询结果,搜索用时 694 毫秒
451.
452.
A. K. Singh 《Russian Journal of Ecology》2016,47(3):310-314
Present study was carried out to determine pollinators’ diversity and their efficiency with modular approach; foraging behaviour, number of loose pollen adhered on their body and number of pollen deposited on the stigma. The observations explicitly indicate that Megachile spp., Xylocopa tenuiscopa, Amegilla zonata and Nomia sp. were true pollinators and out of these, Megachile spp. were key pollinators of pigeonpea. Among megachilids, Megachile lanata was the most efficient pollinator. Sufficient pollination meticulously accomplished in pigeonpea by true pollinators under this agro-ecological region. 相似文献
453.
The animal, agro-wastes and water hyacinth (Eichhornia crassipes) are a serious problem for the society and ecosystem. The present study carried out the management of water hyacinth and observation of nutritional status like pH, electrical conductivity (EC), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), C/N ratio, total phosphorus and total calcium (TCa) of liquid bio-fertilizer (vermiwash) before and after vermicomposting of feed materials of different combinations of buffalo dung (BD) with water hyacinth (WH) and gram bran (GB). After vermicomposting of different combinations of BD with WH and agro-wastes, significant decrease in level of pH, EC, TOC and C/N ratio was observed, whereas significant increase in TKN, TK, TAP and TCa level in vermiwash of final vermicompost with respect to initial feed material was observed. The pH of initial mixture in all combinations has tended to basic in nature, while in final vermicompost, it becomes neutral/basic. The significant increase was observed in the level of TKN, TK, TAP in BD + GB + WH (1:2:1) and TCa in BD + GB + WH (1:1:2) vermiwash of final vermicompost of combination, whereas decrease was observed in TOC, C/N ratio, pH and EC in BD + WH (1:1), BD + GB + WH (1:1:1), BD + GB + WH (1:2:1) and BD + GB (1:1), respectively. 相似文献
454.
455.
Giri Soma Singh Abhay Kumar 《Environmental science and pollution research international》2017,24(17):14945-14956
Environmental Science and Pollution Research - The study was intended to investigate heavy metal contamination levels in the rice grown in the vicinity of the mining areas of Singhbhum Copper Belt,... 相似文献
456.
Prevailing scenario of non-biodegradable food packaging materials worldwide was the motivation for this research. More than half of the packaging materials used today are non-biodegradable and lack one or the other feature that keeps it from being an ideal food packaging material. Based on the current need of food grade packaging materials, the present study illustrates the amelioration of the properties of biodegradable chitosan films with the incorporation of zinc oxide (ZnO) nanoparticles in varying concentration. The ZnO nanoparticles (ZnONPs) used as fillers in the chitosan films were synthesized by supersaturation method. They were characterized using UV–visible spectrophotometry, X-ray diffraction and field emission scanning electron microscopy (FE-SEM). The particles were observed to be around 100–200 nm in size. The chitosan films with varying concentration of ZnONPs were synthesized and characterized using Fourier transform infrared spectroscopy and FE-SEM. The films were studied for their thermal stability, water vapor transmission rate (WVTR) and mechanical properties. The thermal stability, as determined by Thermo Gravimetric Analysis and Differential Scanning Calorimetry increased slightly with increasing percentage of embedded ZnONPs while a substantial decrease in WVTR was observed. Mechanical properties also showed improvements with 77% increment in tensile modulus and 67% increment in tensile strength. The antimicrobial activity of the films was also studied on gram positive bacterium Bacillus subtilis (B. subtilis) and gram negative bacterium Escherichia coli (E. coli) by serial dilution method. A twofold and 1.5-fold increment in the antimicrobial activity was observed for B. subtilis and E. coli, respectively, with increased ZnONPs concentration in the films from 0(w/w) to 2%(w/w). Films thus prepared can prove to be of immense potential in the near future for antimicrobial food packaging applications. 相似文献
457.
Sandip Singh Bhatti Vasudha Sambyal Jaswinder Singh Avinash Kaur Nagpal 《Environment, Development and Sustainability》2017,19(2):571-588
The present study was conducted to determine the physico-chemical properties and heavy metal contents in soils under three land uses (agricultural, riverbank and roadside) from areas situated around rivers (Beas and Sutlej) in Punjab, India. Heavy metal contents in wheat samples (grain and fodder) growing in the area were also analyzed in order to find out potential human health risk through wheat consumption. The studied soils under the three land uses were found to be basic in nature with sandy texture, low soil organic matter and other soil nutrients. Comparatively higher amounts of soil nutrients were observed in soils under agricultural land use as compared to riverbank and roadside land uses. The amounts of heavy metals (Cr, Cu, Co and Pb) analyzed in soils were lower than the various national and international maximum permissible limits, but heavy metal contents observed in wheat fodder samples exceeded the maximum permissible limits for fodder. The soil-to-plant metal bioaccumulation factor was found to be highest for Cu (3.812 for soil–wheat grain and 1.874 for soil–wheat fodder), which showed the bioaccumulation of heavy metals from soils to crops, and the wheat straw-to-grain translocation factor was found to be highest for Co (4.375). The hazard index calculated to assess non-carcinogenic health risks was found above 1 for children, meaning that the wheat grains can pose health risks to children. 相似文献
458.
Improperly managed organic waste constitutes a serious environment threat across the globe. This has led to a worldwide struggle to strike a balance between the rapid generation of such wastes and protection of the environment. With the unique advantages of lower operational and maintenance costs compared with other waste management technologies, the use of vermicomposting to manage organic wastes has been increasing rapidly in recent years. Still, some factors (e.g., characteristics of substrate composition before and after treatment) are in need of additional, specific studies so that researchers can better understand the metabolism involved in the process. Vermicomposting provides employment opportunities as it protects the environment, augmenting crop productivity when it is used as a fertilizer supplement and helping to maintain ecological balance. Thus, vermicompost plays an important role in the circular economy. This article provides an overview of the research activities that have been conducted on the use of vermicomposts to remove pollutants from the soil, in wastewater treatment, and in organic waste recycling throughout the world. Circular economic assessment has revealed that vermicomposting technology is usually feasible except in certain cases. Most other methods of waste disposal lead to soil deterioration, toxic effects, and increased pollution affecting land, air, water, and living beings, in addition to the sometimes considerable expense of their implementation. Thus, an eco‐friendly method that removes waste in one step is needed. Determining the long‐term performance and sustainable operation of vermicomposting systems still poses a challenge, however, as treatment performance is affected by design parameters, operational conditions, and environmental factors. This article summarizes the factors influencing pollutant removal through the vermicomposting process. Finally, this article highlights additional research that should be conducted on these issues to improve the performance of vermicomposting. 相似文献
459.
Andrew Turner Nimisha Singh Jonathan P. Richards 《Environmental pollution (Barking, Essex : 1987)》2009,157(5):1526-1532
Fragments of antifouling paint and environmental geosolids have been sampled from the island of Malta and analysed for total and bioaccessible metals. Total concentrations of Ba, Cd, Cu, Pb, Sn and Zn were two to three orders of magnitude higher in spent antifouling composites relative to respective values in background soils and road dusts. Paint fragments were visible in geosolids taken from the immediate vicinity of boat maintenance facilities and mass balance calculations, based on Ba as a paint tracer, suggested that the most contaminated soils, road dusts and boatyard dusts contained about 1%, 7% and 9%, respectively, of antifouling particles. Human bioaccessibilities of metals were evaluated in selected samples using a physiologically based extraction technique. Accessibilities of Cd, Cu, Pb and Zn in the most contaminated solids were sufficient to be cause for concern for individuals working in the boat repair industry and to the wider, local community. 相似文献
460.
Zn、Cd单一及复合污染对黑麦草根分泌物及根际Zn、Cd形态的影响 总被引:23,自引:6,他引:17
采用根袋土培试验,研究了锌、镉单一及复合污染对重金属富集植物黑麦草生长、锌镉积累、根分泌物及根际Zn、Cd形态的影响.结果表明,锌镉共存下(8 mmol/kg Zn+2 mmol/kg Cd),黑麦草对锌、镉的吸收为协同效应;仅镉污染时(2 mmol/kg Cd),镉对植株吸收锌为抑制效应.黑麦草吸收的锌、镉主要集中在地上部,以锌、镉复合污染时植株地上部对锌、镉的富集量最大,分别达到3 108.72、73.97 mg/kg,具有作为土壤重金属锌、镉污染植物修复材料的潜力.根际的松结合态锌、镉(交换态、碳酸盐结合态和铁锰结合态)含量大于其非根际的松结合态锌、镉含量.Cd污染和Zn、Cd复合污染的根际和非根际土壤镉形态均以交换态>碳酸盐结合态>铁锰结合态>残渣态>有机结合态.Zn污染及Zn、Cd复合污染根际和非根际土壤各锌形态以铁锰结合态>碳酸盐结合态>残渣态>有机结合态>交换态,而Cd污染的根际和非根际的锌形态则以残渣态>铁锰结合态>有机结合态>碳酸盐结合态>交换态.Zn、Cd污染促进了黑麦草根系氨基酸的分泌,降低了根际土壤的pH值,以Zn、Cd复合污染根际土壤氨基酸总量最大,分别为对照、Zn和Cd污染的1.95、1.54和1.40倍,根际土壤的pH值最低(5.18).根际氨基酸含量在重金属胁迫下明显增加,可能与黑麦草适应重金属胁迫有关.根际pH值高于非根际是根际Zn、Cd有效性大于非根际的重要原因. 相似文献