全文获取类型
收费全文 | 391篇 |
免费 | 6篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 8篇 |
废物处理 | 35篇 |
环保管理 | 47篇 |
综合类 | 37篇 |
基础理论 | 66篇 |
污染及防治 | 102篇 |
评价与监测 | 91篇 |
社会与环境 | 13篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 9篇 |
2022年 | 31篇 |
2021年 | 14篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 16篇 |
2016年 | 21篇 |
2015年 | 12篇 |
2014年 | 16篇 |
2013年 | 45篇 |
2012年 | 20篇 |
2011年 | 18篇 |
2010年 | 19篇 |
2009年 | 24篇 |
2008年 | 20篇 |
2007年 | 22篇 |
2006年 | 8篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1963年 | 1篇 |
排序方式: 共有403条查询结果,搜索用时 15 毫秒
361.
362.
Back in 1992, the Gulf of Aqaba Environmental Action Plan (GAEAP), a collaboration between the Aqaba Region Authority (ARA), Jordan and the World Bank, gave considerable emphasis to the environmental protection of the Gulf of Aqaba [The World Bank. Gulf of Aqaba Environmental Action Plan. Report No. 12244JO (1993).]. The document recommended the establishment of a marine reserve and the long term monitoring of the coastal habitats' environmental quality. The combination of a dedicated follow up, the collaborative efforts of ARA and the Marine Science Station (MSS), and the founding of the Aqaba Special Economic Zone Authority (ASEZA) have turned the recommendations into reality. A comprehensive monitoring program of the Jordanian coastal habitats commenced in 1999. The first three years of the program were financed by a donation from The Global Environmental Facility (GEF). In return, Jordan has committed itself to the maintenance of the monitoring program as an ongoing tool for sustainable coastal management. The monitoring program includes observations on benthic habitat, fish communities, bottom sediments and seawater quality. This paper focuses on the results of seawater-quality monitoring in the first three years. Records of weather conditions, coastal currents, seawater temperature, transparency, salinity, density, pH, alkalinity, dissolved oxygen, ammonia, nitrate, nitrite, phosphate, silicate, particulate matter, chlorophyll a, zooplankton biomass, total coliform, fecal coliform, hydrocarbons and sedimentation rate have been generated monthly since January 1999 at six coastal stations, and one offshore reference station, in the Jordanian waters of the Gulf of Aqaba. The coastal stations are located at sites with different benthic habitats and are occupied by different human activities. Offshore records of density (thermohaline structure), nutrients and chlorophyll a depicted two well-defined seasons; a nutrient-/chlorophyll a-rich, mixed water winter from December to April and a nutrient-/chlorophyll a-poor, stratified water summer from June to October. Short transition seasons appeared in May and November. The mixing and stratification seasons were also clearly depicted in the coastal waters. Statistical analysis of the three-year data collected at the offshore station revealed no significant inter-annual differences in the upper 125 m of the water column with respect to any of the measured parameters. At coastal stations, the water quality at the two northernmost stations was significantly different in comparison to the upper 125 m at the offshore station and to the other coastal stations, with respect to the two key indicator parameters: inorganic nitrogen and chlorophyll a. The three-year findings of the monitoring program are employed to suggest standard codes of reference for the coastal water quality. 相似文献
363.
Valto P Knuutinen J Alén R 《Environmental science and pollution research international》2009,16(3):287-294
Background, aim, and scope In papermaking, there is a continuous interest both to minimize fresh water consumption and to reduce discharges into the
environment. These general trends mean an increase in the amounts of detrimental substances, such as resin and fatty acids,
in papermaking process waters. Resin acids, in particular, are responsible for much of the toxicity typically present in paper
mill effluents and, for this reason, the routine and rapid monitoring of these compounds in various process streams is necessary.
This also means that there is a continuous need to develop straightforward offline and online techniques to clarify problems
occurring, for example, as a result of the introduction of more intensively closed systems of water circulation. In the present
study, we describe the use of a novel, online, sample enrichment technique followed by atmospheric pressure chemical ionization–mass
spectrometry (APCI-MS) suitable for monitoring the concentration levels of common resin and fatty acids in papermaking process
waters.
Materials and methods The representative process water samples were taken from the grinding zone of a thermomechanical pulping mill. The samples
were first preconcentrated in a precolumn C18, and the analytes were transferred online to MS. The high intensive [M–H]− ion was used for the identification of each analyte since, according to the present ionization method, no other fragmentation
was observed. Laboratory-scale, online measurements with an online sample feed were carried out by connecting a centrifugal
pump and a ceramic filter to the APCI-MS.
Results Quality parameters, such as repeatability, linearity, and limit of detection (LOD), were determined by using dehydroabietic
acid (DHAA) in order to evaluate the suitability of the method for the rapid screening of concentration levels. This method
provided satisfactory linearity and a good correlation between analyte concentration and peak area. The suitability of the
system for the continuous analysis of the same acids was evaluated in laboratory-scale, online experiments. In all cases,
the response to changes in the analyte concentration was linear, and the repeatability of the system was also satisfactory.
Discussion Only a few studies have been published on the analysis of resin and fatty acids with MS techniques. The present method was
applied to the monitoring of dehydroabietic, oleic, and stearic acids. The quality parameters were highly comparable with
those reported earlier, and the LOD values of the DHAA were below the levels usually encountered in process waters. The quality
parameters were only slightly higher than those obtained by the traditional methods of analysis, probably due to the absence
of an effective sample clean-up before analysis.
Conclusions The results of the laboratory-scale, online experiments indicated that the online enrichment APCI-MS system is a suitable
alternative for monitoring the concentration levels of selected resin and fatty acids in papermaking process waters. The method
can be used, for example, to provide useful information about the concentration levels of these acids in different stages
of the process, thus signaling possibly impending problems. In general, faster and simpler measurements are needed to meet
the requirements for a reduction in fresh water usage in papermaking.
Recommendations and perspectives Compared to the conventional methods used for this purpose, the main benefits of the method are rapidity of measurement, simplicity
of use, and absence of the need for multistage sample treatments (short analysis time). For this reason, this online method
is more suitable for the control of papermaking by analyzing the concentration levels of interfering substances (i.e., selected
resin and fatty acids) than an offline analysis detailing all the individual extractives-based compounds in process streams.
It is also obvious that the technique can easily be modified for other environmental pollutants as well. 相似文献
364.
Saleh K. Al Mansoori Endurance Itsekiri Stefan Iglauer Christopher H. Pentland Branko Bijeljic Martin J. Blunt 《International Journal of Greenhouse Gas Control》2010,4(2):283-288
We measure the trapped non-wetting phase saturation as a function of the initial saturation in sand packs. The application of the work is for CO2 storage in aquifers where capillary trapping is a rapid and effective mechanism to render injected CO2 immobile. The CO2 is injected into the formation followed by chase brine injection, or natural groundwater flow, which displaces and traps CO2 on the pore scale as a residual immobile phase. Current models to predict the amount of trapping are based on experiments in consolidated media, while CO2 may be stored in relatively shallow, poorly consolidated systems. We use analogue fluids at ambient conditions. The trapped saturation initially rises linearly with initial saturation to a value of approximately 0.13 for oil/water systems and 0.14 for gas/water systems. There then follows a region where the residual saturation is constant with further increases in initial saturation. This behaviour is not predicted by the traditional literature trapping models, but is physically consistent with unconsolidated media where most of the larger pores can easily be invaded at relatively low saturation and there is, overall, relatively little trapping. A good match to our experimental data was achieved with the trapping model proposed by Aissaoui. 相似文献
365.
The Henry's law constant (H) is an important parameter in predicting the transport, behavior and fate of organic compounds in environment. H is also required to model the air-water exchange of chemicals. Henry's law constant of formaldehyde (HCHO) was determined at six temperatures (50, 40, 30, 20, 10, and 5 degrees C) using a bubble-column technique. The apparent Henrys law constant (H*) values were strongly correlated to inverse of temperature (1/T, K) and the following relationship was obtained: In H* = (-1,641.3/T)-3.089. Seven concurrent ambient air and aqueous samples were also collected between October 11-17, 2005 at a sampling site located on the shoreline of Tahtali dam Lake in Izmir, Turkey to determine the magnitude and direction (deposition or gas-out) of HCHO flux. In all cases, the modeled gas-phase flux was positive (average +/- SD, 3,181 +/- 408 microg m(-2) day(-1)) indicating that atmospheric HCHO deposited to the Tahtali Lake. 相似文献
366.
The rapid industrialization and urbanization of an area require quick preparation of actual land use/land cover (LU/LC) maps in order to detect and avoid overuse and damage of the landscape beyond sustainable development limits. Remote sensing technology fits well for long-term monitoring and assessment of such effects. The aim of this study was to analyze LU/LC changes between 1980 and 1999 in Samsun, Turkey, using satellite images. Three Landsat images from 1980, 1987 and 1999 were used to determine changes. A post classification technique was used based on a hybrid classification approach (unsupervised and supervised). Images were classified into six LU/LC types; urban, agriculture, dense forest, open forest-hazelnut, barren land and water area. It is found that significant changes in land cover occurred over the study period. The results showed an increase in urban, open forest/hazelnut, barren land and water area and a decrease in agriculture and dense forest in between 1980 and 1999. In this period, urban land increased from 0.77% to 2.47% of the total area, primarily due to conversions from agricultural land and forest to a lesser degree. While the area of dense forest decreased from 41.09% to 29.64% of the total area, the area of open forest and hazelnut increased from 6.73% to 11.88%. 相似文献
367.
Trace metal contents of 28 of refined and unrefined table salt samples from Turkey, Egypt and Greece have been determined by flame atomic absorption spectrometry after coprecipitation by dysprosium(III) hydroxide. Copper, nickel, cobalt, manganese, lead and cadmium levels were found in the range of 0.17-0.47, 0.16-1.57, 0.22-0.48, 0.26-4.68, 0.50-1.64 and 0.14-0.30 microg g(-1), respectively. The results found in the presented work were compared with literature values. 相似文献
368.
Spatial variability of depth and salinity of groundwater under irrigated ustifluvents in the Middle Black Sea Region of Turkey 总被引:2,自引:0,他引:2
Yusuf Demir Sabit Erşahin Mustafa Güler Bilal Cemek Hikmet Günal Hakan Arslan 《Environmental monitoring and assessment》2009,158(1-4):279-294
Information on the potential risk for soil salinity buildup can be very helpful for soil salinity management in irrigated areas. We evaluated the spatial and temporal variability of groundwater salinity (GWS) and groundwater depth (GWD), which are two of the most important indicators of soil salinity, by indicator kriging technique in a large irrigated area in northern Turkey. GWS and GWD were measured on a monthly basis from irrigation season (August 2003) to rainy season (April 2004) at 60 observation wells in the 8,187-ha irrigated area. Five indicator thresholds were used for GWS and GWD. The semivariogram for each of the thresholds for both variables was analyzed then used together with experimental data to interpolate and map the corresponding conditional cumulative distribution functions (CCDF). Risk for soil salinity buildup was greater in the irrigation season compared to that in the rainy season. The greatest risk for soil salinity buildup occurred in the eastern part of the study area, suffering from poor drainage problem due to malfunctioning drainage infrastructure, as indicated by the CCDF of GWS and GWD obtained in both seasons. It was concluded that a combination of mechanical and cultural measures should be taken in high-risk locations to avoid further salinity problems. 相似文献
369.
Ali Alaş Mehmet Musa Özcan Mustafa Harmankaya 《Environmental monitoring and assessment》2014,186(2):889-894
In the experiment, mineral contents of the head, caudal, central fleshy part, and spinal columns of fishes were determined by inductively coupled plasma atomic emission spectrometry. The Ca content of base fleshy part ranged from 1,682 to 5,505 mg/kg. The Ca contents of central fleshy part were found between 104 and 428 mg/kg. This value was found between 5,582 and 7,368 in the spinal column parts. The K content in general ranged from 2,411 (Carassius gibellio) and 4,419 mg/kg (Scomber scombrus). The highest potassium was found on the central fleshy part and ranged between 3,214 and 4,419. The P content was found mostly on the bones and it range between 28,833 and 34,726. The least phosphor amount was found on the central fleshy part. While the Cd content ranges between 0.019 ppm and 0.104 mg/kg, Cr content changed between 1.32 and 4.20 ppm. 相似文献
370.