全文获取类型
收费全文 | 697篇 |
免费 | 47篇 |
国内免费 | 194篇 |
专业分类
安全科学 | 30篇 |
废物处理 | 18篇 |
环保管理 | 122篇 |
综合类 | 347篇 |
基础理论 | 195篇 |
环境理论 | 1篇 |
污染及防治 | 120篇 |
评价与监测 | 51篇 |
社会与环境 | 53篇 |
灾害及防治 | 1篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 19篇 |
2021年 | 30篇 |
2020年 | 22篇 |
2019年 | 14篇 |
2018年 | 23篇 |
2017年 | 27篇 |
2016年 | 31篇 |
2015年 | 39篇 |
2014年 | 41篇 |
2013年 | 81篇 |
2012年 | 45篇 |
2011年 | 77篇 |
2010年 | 54篇 |
2009年 | 44篇 |
2008年 | 31篇 |
2007年 | 62篇 |
2006年 | 55篇 |
2005年 | 48篇 |
2004年 | 21篇 |
2003年 | 33篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 16篇 |
1999年 | 10篇 |
1998年 | 15篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 4篇 |
排序方式: 共有938条查询结果,搜索用时 500 毫秒
711.
为了研究陆生植物博落回(Macleaya Cordata)对不同化学形态铀的富集特征,采用Visual MINTEQ地球化学平衡软件设计了五种含不同化学形态铀[UO22+、CaUO2(CO3)32-、UO2Cit-、(UO2)2(EDTA)24-和UO2HPO4]的培养液,开展水培试验.博落回在这五种培养液中分别培养1、5、10、15、20和25 d后,测定其株高、根长和干质量,并用电感耦合等离子体质谱仪(ICP-MS)测定其地上部分和根部的w(铀).结果表明:在不同化学形态铀胁迫下,博落回株高无显著差异,UO2HPO4可促进博落回根的生长,而(UO2)2(EDTA)24-降低了博落回的干质量.并且,博落回根部对不同化学形态铀的富集能力大小顺序为UO22+ > UO2HPO4 > CaUO2(CO3)32- > UO2Cit- >(UO2)2(EDTA)24-,博落回地上部分对不同化学形态铀的富集能力大小顺序为UO2Cit- >(UO2)2(EDTA)24- > UO22+ > CaUO2(CO3)32- > UO2HPO4.此外,博落回根部对UO22+的富集能力很高,但地上部分很低.添加柠檬酸,培养液中铀的主要化学形态为UO2Cit-,并且在100 mg/L铀的胁迫下,博落回对UO2Cit-的生物富集系数和转移系数分别达到0.09和8.53.因此,要提高博落回对铀污染土壤中铀的富集和转移,可添加柠檬酸,促使土壤中铀的形态以UO2Cit-为主,同时要降低土壤中碳酸盐和磷酸盐的含量. 相似文献
712.
高等水生植物修复双龙湖水体叶绿素a变化试验研究 总被引:10,自引:0,他引:10
重庆渝北双龙湖水体因长期受纳城市污水,近几年水体水质恶化并呈加重趋势,为治理修复该水体,进行了水面种植高等植物净化双龙湖富营养化水体的动态和静态试验研究。结果表明,试验植物风车草、蕹菜,芹菜对叶绿素a的降低率分别是17.64%、42.99%、38.05%,附着物与根系重量比(湿重%)是风车草:5.1-132.7、芹菜:100.0、蕹菜:48.3;三种植物对富营养化水体有较好的修复作用,对降低叶绿素a作用明显,对悬浮污染物有较好的吸附作用,其中风车草对修复营养化水体的作用应予重视。 相似文献
713.
714.
One of the primary adverse environmental impacts associated with power generation facilities and in particular thermal power plants is local air quality. When these plants are operated at inland areas the dry type cooling towers used may significantly increase ambient concentrations of air pollutants due to the building downwash effect. When one or more buildings in the vicinity of a point source interrupt wind flow, an area of turbulence known as a building wake is created. Pollutants emitted from relatively low level sources can be caught in this turbulence affecting their dispersion. In spite of the fact that natural gas-fired combined-cycle power plants have lower air emission levels compared to other power plants using alternative fossil fuel, they can still create significant local air pollution problems. In this paper, local air quality impacts of a natural gas-fired combined-cycle power plant located in a coastal area are compared with those of another natural gas-fired combined-cycle power plant having identical air emissions but located in an inland area taking into account differences in topography and meteorology. Additionally, a series of scenarios for the inland site have been envisaged to illustrate the importance of plant lay-out configurations paying particular attention to the building downwash effect. Model results showed that different geometrical configurations of the stacks and cooling towers will cause remarkable differences in ambient air pollutant concentrations; thus it is concluded that when selecting a plant site, a detailed site-specific investigation should be conducted in order to achieve the least possible ambient air pollution concentrations with the given emissions. 相似文献
715.
Uera RB Paz-Alberto AM Sigua GC 《Environmental science and pollution research international》2007,14(7):505-509
Background, Aims and Scope Research and development has its own benefits and inconveniences. One of the inconveniences is the generation of enormous
quantity of diverse toxic and hazardous wastes and its eventual contamination to soil and groundwater resources. Ethidium
bromide (EtBr) is one of the commonly used substances in molecular biology experiments. It is highly mutagenic and moderately
toxic substance used in DNA-staining during electrophoresis. Interest in phytoremediation as a method to solve chemical contamination
has been growing rapidly in recent years. The technology has been utilized to clean up soil and groundwater from heavy metals
and other toxic organic compounds in many countries like the United States, Russia, and most of European countries. Phytoremediation
requires somewhat limited resources and very useful in treating wide variety of environmental contaminants. This study aimed
to assess the potential of selected tropical plants as phytoremediators of EtBr.
Materials and Methods This study used tomato (Solanum lycopersicum), mustard (Brassica alba), vetivergrass (Vetiveria zizanioedes), cogongrass (Imperata cylindrica), carabaograss (Paspalum conjugatum), and talahib (Saccharum spontaneum) to remove EtBr from laboratory wastes. The six tropical plants were planted in individual plastic bags containing soil and
10% EtBr-stained agarose gel. The plants were allowed to establish and grow in soil for 30 days. Ethidium bromide content
of the test plants and the soil were analyzed before and after soil treatment. Ethidium bromide contents of the plants and
soils were analyzed using an UV VIS spectrophotometer.
Results Results showed a highly significant (p≤0.001) difference in the ability of the tropical plants to absorb EtBr from soils.
Mustard registered the highest absorption of EtBr (1.4±0.12 μg kg−1) followed by tomato and vetivergrass with average uptake of 1.0±0.23 and 0.7±0.17 μg kg−1 EtBr, respectively. Cogongrass, talahib, and carabaograss had the least amount of EtBr absorbed (0.2±0.6 μg kg−1). Ethidium bromide content of soil planted to mustard was reduced by 10.7%. This was followed by tomato with an average reduction
of 8.1%. Only 5.6% reduction was obtained from soils planted to vetivergrass. Soils planted to cogongrass, talahib, and carabaograss
had the least reduction of 1.52% from its initial EtBr content.
Discussion In this study, mustard, tomato, and vetivergrass have shown their ability to absorb EtBr from contaminated soil keeping them
from expanding their reach into the environment and preventing further contamination. Its downside, however, is that living
creatures including humans, fish, and birds, must be prevented from eating the plants that utilized these substances. Nonetheless,
it is still easier to isolate, cut down, and remove plants growing on the surface of the contaminated matrices, than to use
strong acids and permanganates to chemically neutralize a dangerous process that can further contaminate the environment and
pose additional risks to humans. Though this alternative method does not totally eliminate eventual environmental contamination,
it is by far produces extremely insignificant amount of by-products compared with the existing processes and technologies.
Conclusions Mustard had the highest potential as phytoremediator of EtBr in soil. However, the absorption capabilities of the other test
plants may also be considered in terms of period of maturity and productivity.
Recommendations and Perspectives It is recommended that a more detailed and complete investigation of the phytoremediation properties of the different plants
tested should be conducted in actual field experiments. Plants should be exposed until they reach maturity to establish their
maximum response to the toxicity and mutagenecity of EtBr and their maximum absorbing capabilities. Different plant parts
should be analyzed individually to determine the movement and translocation of EtBr from soil to the tissues of plants. Since
this study has established that some plants can thrive and dwell in EtBr-treated soil, an increased amount of EtBr application
should be explored in future studies. It is suggested therefore that a larger, more comprehensive exploration of phytoremediation
application in the management of toxic and hazardous wastes emanating from biotechnology research activities should be considered
especially on the use of vetivergrass, a very promising tropical perennial grass.
ESS-Submission Editor: Professor Zhihong Xu (zhihong.xu@griffith.edu.au: www.griffith.edu.au/centre/cfhr) 相似文献
716.
为降低泄漏频率对化工装置定量风险分析结果不确定性的影响,从覆盖设备设施类型、基准泄漏频率和频率计算模型等方面,比较分析中国、英国健康安全管理局、挪威船级社、国际油气生产商联合会(IOGP)发布的泄漏频率数据源,筛选出更适合计算化工装置泄漏频率的数据源;并以某化工装置2个泄漏单元为例,比较《危险化学品生产装置和储存设施外... 相似文献
717.
污水处理厂除臭工艺选择及工程设计 总被引:2,自引:0,他引:2
随着无锡市城北污水处理厂二期工程的扩建,污水处理厂除臭问题日益突出.针对目前常用的化学、活性炭吸附、氧离子基团、燃烧、纯天然植物提取液喷洒和生物等6种除臭方法,重点说明了除臭工艺的选择及除臭系统的工程设计,最后结合运行情况总结了除臭系统的设计特点. 相似文献
718.
火电厂烟气脱硝容量的合理性探讨 总被引:1,自引:0,他引:1
根据美国20世纪90年代初的电力生产及火电NOx的排放情况,并结合我国的实际情况及控制火电NOx排放的趋势,提出2010年和2020年我国火电NOx排放总量控制目标,预测满足火电NOx控制目标的合理的火电厂烟气脱硝容量. 相似文献
719.
文章采用多源多时相高分辨率遥感影像作为数据源,以ArcGIS、Erdas、Envi等遥感地信软件为信息提取平台,对青海省湟水流域的采砂场进行遥感调查分析。结果显示:①采砂场主要分布在湟水流域城市周边,其中,在用采砂场分布较密集,如西宁、湟中、平安附近分布较集中,而停用采砂场分布相对比较均匀;②采砂场共305处,其中长期和临时采砂场占重要比例,达73%,经过平整或绿化的停用采砂场较少,而停用且无整改及整改中的采砂场数量仍较多,是已整改的2倍;③长期采砂场面积规模占所有类型总面积的比重最大,达三分之二,而经过平整或已绿化的规模仅0.75 km2。研究以期对环境监察管理提供技术支撑,为后续的研究和砂场的高效精准管理提供技术方法和科学依据。 相似文献
720.