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251.
海上油田含油污水旋流气浮一体化处理设备及其应用 总被引:2,自引:0,他引:2
低强度旋流离心力场与气浮组合是一种高效的含油污水处理技术,目前在国外已有较为成熟的产品,尤其是挪威M-I SWACO公司开发的Epcon紧凑型气浮装置已经在海上油田含油污水处理的应用方面取得了众多成功的案例。从Epcon紧凑型气浮装置的基本结构及其工作原理入手,简要叙述了该设备的工艺流程和性能特点,重点介绍了其在世界范围内尤其是在中国西江30-2采油平台上的测试和应用状况,最后介绍了新一代CFU设备的研发动向,为国内自主设计研发含油污水旋流气浮一体化处理设备提供必要的理论指导。 相似文献
252.
Joseph O. Lalah Bonface M. Muendo Zachary M. Getenga 《Journal of environmental science and health. Part. B》2013,48(7):690-696
The dissipation of hexazinone (Velpar) in two tropical soil types in Kenya was studied under field and semi-controlled conditions for a period of 84 days. The dissipation was found to be very rapid and this could be attributed to adverse weather conditions including high initial rainfall as well as to low soil-organic-matter content, volatilization, surface run-off and biodegradation. The DT50 values of dissipation obtained by first order kinetics were 20 days and 21.3 days in clay and loam soil types, respectively. The influence of bargasse compost (1000 μg/g dry soil) was also studied and was found to enhance dissipation to some extent, giving DT50 values of 18 days and 18.3 days in clay and loam soil types, respectively. 相似文献
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Oleksiy Ivaschenko Jesse Doyle Jaekyun Kim Jonathan Sibley Zaineb Majoka 《Disasters》2020,44(3):455-476
This paper contributes to the evidence on the effectiveness of shock-responsive social protection systems in helping affected households recover from the negative consequences of disasters. It evaluates the influence of the top-up cash transfers provided by the Government of Fiji to poor households in the wake of Tropical Cyclone Winston, which struck the Pacific Island country on 20 February 2016. The impact evaluation strategy incorporates a sharp regression discontinuity design to define treatment and control groups, based on the eligibility threshold of the poverty benefit scheme. The results indicate that treatment households—that is, those that received cash transfers—are significantly more likely to report quicker recovery from various shocks. Female-headed households are more likely to recover from the ramifications, whereas households with older heads are less likely to do so. The presence of a functioning market appears to be a major factor aiding the speed of recovery. Finally, the evidence points towards strong district effects on recovery. 相似文献
255.
西北太平洋热带气旋的时空分布特征分析 总被引:6,自引:0,他引:6
西北太平洋是世界上热带气旋(TC)发生频率最高、强度最强的一个海区,因此对西北太平洋TC进行气候分析是很有意义的.根据1945-2006年JTWC的数据资料对西北太平洋的热带气旋时空分布特征进行了统计分析,得到TC活动的一些最新概况.从时间分布特征上来看:TC频数呈增加趋势,有两个上升阶段,两个下降阶段;台风和强台风与TC的变化趋势大致相同,但自2000年至今有上升趋势;在季节上分布上,热带气旋,台风和强台风频数存在时间上的延迟现象.从空间分布特征来看:TC源地在0°~30°N范围内,纬向发生高频区轴线位于12.6°N,经向对应于南海海区和菲律宾以东及关岛附近洋面有两个峰值;TC强度越强,其发生高频区纬向轴线向赤道方向移动,而经向轴线向东移动;南海海区不是强台风的高发区;台风和强台风源地高频区经向轴线在145°~155°E之间移动;纬向轴线在6°~14°E之间移动,强台风的源地高频区经向轴线始终位于台风轴线的东侧,而纬向轴线位于其南侧. 相似文献
256.
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
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259.
珠江三角洲大暴雨的多普勒特征及形成机制 总被引:2,自引:0,他引:2
利用广州CINRAD-SA新一代多普勒天气雷达资料,结合天气形势分析,研究了华南地区夏季短时大暴雨的发生、发展过程,特别是中小尺度系统引发短时大暴雨不同发展阶段的多普勒特征以及辐合强度与短时大暴雨的关系,并对短时大暴雨的发展机制进行了初步探讨.通过分析发现,短时大暴雨产生于低空强盛西南气流等有利条件下,近地层雨区附近的气旋式扰动有利于激发对流,抽吸作用、局地锋生对对流的维持和加强起到了十分重要的作用.在短时大暴雨发生初期及发展旺盛期,大多数都伴有逆风区、辐合带等多普勒特征,中气旋更是与高强度降水、地面强风等剧烈天气密切相关. 相似文献
260.