全文获取类型
收费全文 | 2239篇 |
免费 | 17篇 |
国内免费 | 91篇 |
专业分类
安全科学 | 105篇 |
废物处理 | 210篇 |
环保管理 | 280篇 |
综合类 | 293篇 |
基础理论 | 392篇 |
环境理论 | 1篇 |
污染及防治 | 783篇 |
评价与监测 | 193篇 |
社会与环境 | 75篇 |
灾害及防治 | 15篇 |
出版年
2023年 | 11篇 |
2022年 | 33篇 |
2021年 | 36篇 |
2020年 | 12篇 |
2019年 | 41篇 |
2018年 | 70篇 |
2017年 | 58篇 |
2016年 | 78篇 |
2015年 | 54篇 |
2014年 | 67篇 |
2013年 | 178篇 |
2012年 | 123篇 |
2011年 | 143篇 |
2010年 | 96篇 |
2009年 | 129篇 |
2008年 | 134篇 |
2007年 | 145篇 |
2006年 | 128篇 |
2005年 | 114篇 |
2004年 | 105篇 |
2003年 | 97篇 |
2002年 | 88篇 |
2001年 | 62篇 |
2000年 | 35篇 |
1999年 | 24篇 |
1998年 | 20篇 |
1997年 | 23篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 18篇 |
1993年 | 19篇 |
1992年 | 10篇 |
1991年 | 19篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1978年 | 6篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 5篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 5篇 |
排序方式: 共有2347条查询结果,搜索用时 281 毫秒
181.
In situ iron activated persulfate oxidative fluid sparging treatment of TCE contamination--a proof of concept study 总被引:1,自引:0,他引:1
In situ chemical oxidation (ISCO) is considered a reliable technology to treat groundwater contaminated with high concentrations of organic contaminants. An ISCO oxidant, persulfate anion (S(2)O(8)(2-)) can be activated by ferrous ion (Fe(2+)) to generate sulfate radicals (E(o)=2.6 V), which are capable of destroying trichloroethylene (TCE). The property of polarity inhibits S(2)O(8)(2-) or sulfate radical (SO(4)(-)) from effectively oxidizing separate phase TCE, a dense non-aqueous phase liquid (DNAPL). Thus the oxidation primarily takes place in the aqueous phase where TCE is dissolved. A bench column study was conducted to demonstrate a conceptual remediation method by flushing either S(2)O(8)(2-) or Fe(2+) through a soil column, where the TCE DNAPL was present, and passing the dissolved mixture through either a Fe(2+) or S(2)O(8)(2-) fluid sparging curtain. Also, the effect of a solubility enhancing chemical, hydroxypropyl-beta-cyclodextrin (HPCD), was tested to evaluate its ability to increase the aqueous TCE concentration. Both flushing arrangements may result in similar TCE degradation efficiencies of 35% to 42% estimated by the ratio of TCE degraded/(TCE degraded+TCE remained in effluent) and degradation byproduct chloride generation rates of 4.9 to 7.6 mg Cl(-) per soil column pore volume. The addition of HPCD did greatly increase the aqueous TCE concentration. However, the TCE degradation efficiency decreased because the TCE degradation was a lower percentage of the relatively greater amount of dissolved TCE by HPCD. This conceptual treatment may serve as a reference for potential on-site application. 相似文献
182.
Ozonation of pentachlorophenol in unsaturated soils 总被引:1,自引:0,他引:1
A heterogeneous model was developed to describe interactions between ozone and hydrophobic organic compounds, exemplified by pentachlorophenol, in highly gas-saturated vadose zones where water moisture was limited to a thin film on soil particle surfaces. The soil was assumed to be free of soil organic matter. The model included a set of transient equations considering diffusion with simultaneous chemical reaction and hydrophobic partitioning. From dimensionless analysis, it was found that the film concentrations of ozone and the hydrophobic organic component were dependent on the Damk?hler numbers. Effects of Damk?hler numbers on the film profiles of components were examined. With the interfacial flux of ozone calculated from film profiles, dimensionless governing equations of ozone transport and contaminant removal across an experimental column were established. These equations were dependent on the Stanton number. One-dimensional column experiments were conducted to test the model. The optimal time for flow rate adjustment during the process was approximated. Finally, effects of ozone velocity and ozone gas concentration on the Stanton number were evaluated. 相似文献
183.
A comparison of the low frequency electrical signatures of iron oxide versus calcite precipitation in granular zero valent iron columns 总被引:1,自引:1,他引:0
Geophysical methods have been proposed as technologies for non-invasively monitoring geochemical alteration in permeable reactive barriers (PRBs). We conducted column experiments to investigate the effect of mineralogy on the electrical signatures resulting from iron corrosion and mineral precipitation in Fe0 columns using (a) Na2SO4, and (b) NaHCO3 plus CaCl2 mixture, solutions. At the influent interface where the reactions were most severe, a contrasting time-lapse electrical response was observed between the two columns. Solid phase analysis confirmed the formation of corrosion halos and increased mineralogical complexity in the corroded sections of the columns compared to the minimal/non-corroded sections. We attribute the contrasting time-lapse signatures to the differences in the electrical properties of the mineral phases formed within the two columns. While newly precipitated/transformed polarizable and semi-conductive iron oxides (mostly magnetite and green rust) increase the polarization and conductivity of the sulfate column, the decrease of both parameters in the bicarbonate column is attributed to the precipitation of non-polarizable and non-conductive calcite. Our results show that precipitate mineralogy is an important factor influencing the electrical properties of the corroded iron cores and must be considered if electrical geophysical methods are to be developed to monitor PRB barrier corrosion processes in situ. 相似文献
184.
An entrained-flow system has been designed and constructed to simulate in-flight mercury capture by sorbents in ducts of coal-fired
utility plants. The test conditions of 1.5 s residence time, 140°C temperature, 4.5 ppbv inlet Hg0 concentration, and 0–20 lb/MMacf sorbent injection rates were chosen to simulate conditions in the ducts. Novel oxidants
developed in previous fixed-bed tests and novel sorbents derived from the novel oxidants were tested for their Hg0 capture in the entrained-flow system to examine the possibility of using those sorbents in a full-scale system. Darco-FGD
and Darco Hg-LH served as benchmark sorbents with which mercury control capability of the novel oxidants and novel sorbents
could be compared. The test results showed that the novel oxidants have remarkable Hg0 oxidation capability, and the novel sorbents showed a better performance in Hg0 removal than Darco Hg-LH. 相似文献
185.
186.
Environmental and Ecological Statistics - 相似文献
187.
Effects of salinity on endogenous rhythm of the Manila clam, Ruditapes philippinarum (Bivalvia: Veneridae) 总被引:1,自引:0,他引:1
The Manila clam Ruditapes philippinarum, an intertidal bivalve, was exposed to different salinity regimes (from 31.0–31.7‰ down to 20‰, 15‰, 10‰, 5‰), and the endogenous
rhythm in its oxygen consumption was studied using an automatic intermittent-flow respirometer. When exposed to salinities
reduced from 31.5‰ to 20‰ and 15‰ under otherwise constant conditions, the clams recovered a clear endogenous circatidal rhythm
in their oxygen-consumption rate after having dampened periods of 12 h and 48 h, respectively. At salinities less than 10‰,
however, the oxygen-consumption rate was depressed greatly at the beginning of the experiment for about 36 h and then increased
to a level higher than normal, but the rhythm of oxygen consumption was not recovered. The results of this study indicate
that the Manila clam, a euryhaline organism, cannot maintain a normal metabolic activity at a salinity lower than 15‰. All
clams were dead after exposure at a salinity of 5‰ for 7 days.
Received: 28 February 2000 / Accepted: 26 August 2000 相似文献
188.
D. Kim T. Okamoto T. Oda K. Tachibana K.S. Lee A. Ishimatsu Y. Matsuyama T. Honjo T. Muramatsu 《Marine Biology》2001,139(4):625-632
Although the ichthyotoxic mechanism of Chattonella marina is still unknown, several lines of evidence suggest that the reactive oxygen species (ROS), such as superoxide anion (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (·OH), produced by C. marina are involved in the mortality of fish exposed to this flagellate. Recently, we found that the cell-free supernatant prepared from C. marina, which is considered to contain the glycocalyx, showed NADPH-dependent O2- generation. In this study, we prepared antiserum against the crude glycocalyx of C. marina. Using indirect immunofluorescence, it was confirmed that the antiserum specifically reacted with C. marina cells. In addition to C. marina, the antiserum also reacted with other raphidophycean flagellates such as Heterosigma akashiwo, Olisthodiscus luteus, and Fibrocapsa japonica, whereas no reactivity was observed against six other flagellate species tested. These results suggest that raphidophycean flagellates have common epitopes recognized by the antiserum. Interestingly, immunohistochemical analysis of paraformaldehyde-fixed gill lamellae from yellowtail exposed to C. marina revealed that the antiserum stained the surface of gill lamellae, while no such staining pattern was observed in control gill lamellae. These results suggest that the glycocalyx may be discharged when C. marina cells are inhaled into the fishes' mouths and then come into contact with the gill surface. Based on the present results, together with our previous findings, we propose that continuous accumulation of the discharged glycocalyx on the gill surface occurs during C. marina exposure, which may be responsible for the ROS-mediated severe gill tissue damage leading to fish death. 相似文献
189.
Tsung-Hung Hsu Jen-Yang Lin Tsu-Chuan Lee Harry X. Zhang Shaw L. Yu 《Environmental monitoring and assessment》2010,163(1-4):81-94
It is vitally important to define the critical condition for a receiving water body in the total maximum daily load (TMDL) development process. One of the major disadvantages of using a continuous simulation approach is that there is no guarantee that the most critical condition will be covered within the subjectively selected representative hydrologic period, which is usually several years depending on the availability of data. Another limitation of the continuous simulation approach, compared to a design storm approach, is the lack of an estimate of the risk involved. Because of the above limitations, a storm event-based critical flow-storm (CFS) approach was previously developed to explicitly address the critical condition as a combination of a prescribed stream flow and a storm event of certain magnitude, both having a certain frequency of occurrence and when combined, would create a critical condition. The CFS approach was tested successfully in a TMDL study for Muddy Creek in Virginia. The present paper reports results of a comparative study on the applicability of the CFS approach in Taiwan. The Dy-yu creek watershed in northern Taiwan differs significantly from Muddy Creek in terms of climate, hydrology, terrain, and other characteristics. Results show that the critical condition for different watersheds might be also different, and that the CFS approach could clearly define that critical condition and should be considered as an alternative method for TMDL development to a continuous simulation approach. 相似文献
190.
Kim NS Sakong J Choi JW Hong YS Moon JD Lee BK 《Environmental monitoring and assessment》2012,184(7):4139-4149
In 2007, as part of the control and prevention of environmental contamination threatening public health, the Korean Ministry of Environment planned to implement a national biomonitoring survey of three metals: lead, cadmium, and mercury in the blood of residents living near 350 abandoned metal mines known to be contaminated and as possible threats to the health of inhabitants. Thus, we investigated demographic and lifestyle variables and blood lead levels in residents living around the mines and compared them against those of control subjects. We measured the blood lead concentrations in 14,849 subjects (14,132 from nearby the 350 abandoned metal mines and 717 subjects from eight control areas). A questionnaire was provided to all subjects to determine gender, age, mining experience, period of time living in the vicinity of mines, smoking status, and personal perception of abandoned mines as a health risk. The geometric means (95% confidence intervals) of the blood lead levels of residents living around the abandoned metal mines and control areas were 3.017 (2.996-3.037 μg/dL) [female, 2.797 μg/dL (2.771-2.822 μg/dL); male, 3.330 μg/dL (3.298-3.363 μg/dL)] and 2.757 (2.677-2.837 μg/dL) [female, 2.604 μg/dL (2.506-2.700 μg/dL); male, 2.993 μg/dL (2.859-3.126 μg/dL)], respectively. Among residents of the mining areas, nonsmokers and residents who had no mining experience showed significantly lower mean blood lead levels than did smokers, past smokers, and those with mining experience. The mean blood lead concentrations of residents who expressed some concern about the abandoned mines were significantly higher than those of residents without concerns. The mean blood lead concentration of residents living around the abandoned mines was significantly higher than that of residents living in control areas as well as that of the general adult Korean population. We also confirmed that smoking is an important variable to consider, as it increases blood lead concentration. 相似文献