全文获取类型
收费全文 | 619篇 |
免费 | 6篇 |
国内免费 | 25篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 87篇 |
环保管理 | 57篇 |
综合类 | 81篇 |
基础理论 | 91篇 |
环境理论 | 1篇 |
污染及防治 | 226篇 |
评价与监测 | 58篇 |
社会与环境 | 19篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 10篇 |
2022年 | 8篇 |
2021年 | 10篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 20篇 |
2017年 | 31篇 |
2016年 | 28篇 |
2015年 | 18篇 |
2014年 | 25篇 |
2013年 | 58篇 |
2012年 | 33篇 |
2011年 | 48篇 |
2010年 | 34篇 |
2009年 | 45篇 |
2008年 | 43篇 |
2007年 | 41篇 |
2006年 | 42篇 |
2005年 | 30篇 |
2004年 | 31篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 7篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有650条查询结果,搜索用时 93 毫秒
241.
242.
Ok-Kyung Koo Christopher A. Baker Hyun-Jung Kim Si Hong Park 《Journal of environmental science and health. Part. B》2016,51(9):622-627
The purpose of this study was to characterize the microbial community in ground pork using molecular approaches. Forty six ground pork products were purchased from local stores in the north central area of South Korea. Aerobic plate counts varied 4.23 ± 5.14 × 105 CFU/g with the range between 5.00 × 103 and 1.85 × 106 CFU/g for ground pork samples. Four ground meat samples were further processed for metagenomic analysis. Pseudomonas species was the most relative abundant with a wide range occurring (1.72 to 77.7%) as part of the microbial genera in ground pork. Bacteria such as Carnobacterium, Yersinia, Photobacterium were also identified in ground pork. Despite the prominence of certain genera across all samples there was still extensive microbial diversity among ground pork products that originated from different slaughter houses and were processed in different markets. Such diversity indicates that designing interventions to extend shelf life may be hampered by the extensive variability in the microbial consortia associated with pork products. However, this diversity may be useful for developing microbial traceability signatures unique to a slaughter house or a particular market. 相似文献
243.
Dae-Young Kim Hong-Youl Ryu Seung-Hyun Kim Kyoung-Tae Park Seong-Seock Cho Moon-Hee Han 《International Journal of Green Energy》2016,13(6):573-579
A novel on-board hydrogen generation concept using Al coil with NaOH was investigated. The reaction rate was successfully controlled by introducing a pumping system for the NaOH solution. The time for the flow to develop fully was mainly dependent on the solution temperature, and the fastest start time recorded was 60 sec at a solution temperature of 70°C. The maximum H2 generation rate was 200 L min–1 with a prototype design of the on-board hydrogen generation system 1/8 times the size of a full-size reactor. The H2 generation process coupled with the solution pumping system was simulated with three-dimensional fluid dynamic software, and the calculated H2 flow and temperature rise of the system were validated with experimental data. 相似文献
244.
245.
Hong Geng Hae-Jin Jung YooMyung Park HeeJin Hwang HyeKyeong Kim Yoo Jung Kim Young Sunwoo Chul-Un Ro 《Atmospheric environment (Oxford, England : 1994)》2009,43(21):3364-3373
Determination of the chemical compositions of atmospheric single particles in the Yellow Sea region is critical for evaluating the environmental impact caused by air pollutants emitted from mainland China and the Korean peninsula. After ambient aerosol particles were collected by the Dekati PM10 cascade impactor on July 17–23, 2007 at Tokchok Island (approximately 50 km west of the Korean coast nearby Seoul), Korea, overall 2000 particles (on stage 2 and 3 with cut-off diameters of 2.5–10 μm and 1.0–2.5 μm, respectively) in 10 samples were determined by using low-Z particle electron probe X-ray microanalysis. X-ray spectral and secondary electron image (SEI) data showed that soil-derived and sea-salt particles which had reacted or were mixed with SO2 and NOx (or their acidic products) outnumbered the primary and “genuine” ones (59.2% vs. 19.2% in the stage 2 fraction and 41.3% vs. 9.9% in the stage 3 fraction). Moreover, particles containing nitrate in the secondary soil-derived species greatly outnumbered those containing sulfate. Organic particles, mainly consisting of marine biogenic species, were more abundant in the stage 2 fraction than in the stage 3 fraction (11.6% vs. 5.1%). Their relative abundance was greater than the sum of carbon-rich, K-containing, Fe-containing, and fly ash particles, which exhibited low frequencies in all the samples. In addition, many droplets rich in C, N, O, and S were observed. They tended to be small, exhibiting a dark round shape on SEI, and generally included 8–20 at.% C, 0–12 at.% N, 60–80 at.% O, and 4–10 at.% S (sometimes with <3 at.% Mg and Na). They were attributed to be a mixture of carbonaceous matter, H2SO4, and NH4HSO4/(NH4)2SO4, mostly from the reaction of atmospheric SO2 with NH3 under high relative humidity. The analysis of the relationship between the aerosol particle compositions and 72-h backward air-mass trajectories suggests that ambient aerosols at Tokchok Island are strongly affected not only by seawater from the Yellow Sea but also by anthropogenic pollutants emitted from China and the Seoul–Incheon metropolis, resulting in the dominance of complex secondary aerosol particles. 相似文献
246.
S.H. Park S.L. Gong W. Gong P.A. Makar M.D. Moran C.A. Stroud J. Zhang 《Atmospheric environment (Oxford, England : 1994)》2009,43(19):3122-3129
Recently, a wind-blown-dust-emission module has been built based on a state-of-the-art wind erosion theory and evaluated in a regional air-quality model to simulate a North American dust storm episode in April 2001 (see Park, S.H., Gong, S.L., Zhao, T.L., Vet, R.J., Bouchet, V.S., Gong, W., Makar, P.A., Moran, M.D., Stroud, C., Zhang, J. 2007. Simulation of entrainment and transport of dust particles within North America in April 2001 (“Red Dust episode”). J. Geophys. Res. 112, D20209, doi:10.1029/2007JD008443). A satisfactorily detailed assessment of that module, however, was not possible because of a lack of information on some module inputs, especially soil moisture content. In this paper, the wind-blown-dust emission was evaluated for two additional dust storms using improved soil moisture inputs. The surface characteristics of the wind-blown-dust source areas in southwestern North America were also investigated, focusing on their implications for wind-blown-dust emissions. The improved soil moisture inputs enabled the sensitivity of other important surface characteristics, the soil grain size distribution and the land-cover, to dust emission to be investigated with more confidence. Simulations of the two 2003 dust storm episodes suggested that wind-blown-dust emissions from the desert areas in southwestern North America are dominated by emissions from dry playas covered with accumulated alluvial deposits whose particle size is much smaller than usual desert sands. As well, the source areas in the northwestern Texas region were indicated to be not desert but rather agricultural lands that were “activated” as a wind-blown-dust sources after harvest. This finding calls for revisions to the current wind-blown-dust-emission module, in which “desert” is designated to be the only land-cover category that can emit wind-blown dust. 相似文献
247.
Since the majority of schools are housed in buildings dating from the 1960s and 1970s, a comprehensive construction and renovation program of school buildings has been carried out to improve the educational conditions in Korea. However, classrooms and computer rooms, with pressed wood desks, chairs and furnishings, as well as construction materials, might have negative effects on the indoor air quality. Furthermore, most schools have naturally ventilated classrooms. The purpose of this study was to characterize the concentrations of different indoor air pollutants within Korean schools and to compare their indoor levels within schools according to the age of school buildings. Indoor and outdoor air samples of carbon monoxide (CO), carbon dioxide (CO(2)), particulate matter (PM(10)), total microbial count (TBC), total volatile organic compounds (TVOCs) and formaldehyde (HCHO) were obtained during summer, autumn and winter from three sites; a classroom, a laboratory and a computer classroom at 55 different schools. The selection of the schools was based on the number of years since the schools had been constructed. The problems causing indoor air pollution at the schools were chemicals emitted by building materials or furnishings, and insufficient ventilation rates. The I/O ratio for HCHO was 6.32 during the autumn, and the indoor HCHO concentrations (mean = 0.16 ppm) in schools constructed within 1 year were significantly higher than the Korean Indoor Air Standard, indicating that schools have indoor sources of HCHO. Therefore, increasing the ventilation rate by means of a mechanical system and the use of low-emission furnishings can play key roles in improving the indoor air quality within schools. 相似文献
248.
The endogenous rhythm of oxygen consumption in juvenile spotted sea bass (Lateolabrax sp.) was measured to test the effects of sudden changes in salinity on the metabolic activity. Mean oxygen consumption rates
of this euryhaline fish decreased by 13.5 to 16.0% and 25.3 to 36.4% when they were transferred from 31.5 to 15‰ seawater
and to fresh water (0‰), respectively. The maximum rate of oxygen consumption was observed between 18:00 and 19:00 hrs local
time, 1 to 2 h before sunset, even though they were kept in constant darkness. The peaks of oxygen consumption occurred in
23.2- and 23.3-h intervals, which correspond with a circadian rhythm, as revealed by maximum entropy spectral analysis. A
markedly weakened rhythm in oxygen consumption occurred from 8 to 10 d after onset of the experiments. This study indicates
that spotted sea bass can withstand sudden drops in salinity from 31.5‰ to fresh water, and yet maintain a regular though
somewhat dampened endogenous rhythm of oxygen consumption.
Received: 16 June 1997 / Accepted: 3 February 1998 相似文献
249.
250.
Effects of humic acid on phytoremediation of petroleum hydrocarbons in soil simultaneously contaminated with heavy metals were evaluated. 相似文献