全文获取类型
收费全文 | 2947篇 |
免费 | 28篇 |
国内免费 | 33篇 |
专业分类
安全科学 | 80篇 |
废物处理 | 158篇 |
环保管理 | 306篇 |
综合类 | 500篇 |
基础理论 | 601篇 |
环境理论 | 2篇 |
污染及防治 | 880篇 |
评价与监测 | 263篇 |
社会与环境 | 196篇 |
灾害及防治 | 22篇 |
出版年
2023年 | 32篇 |
2022年 | 100篇 |
2021年 | 127篇 |
2020年 | 60篇 |
2019年 | 50篇 |
2018年 | 117篇 |
2017年 | 110篇 |
2016年 | 131篇 |
2015年 | 82篇 |
2014年 | 124篇 |
2013年 | 185篇 |
2012年 | 145篇 |
2011年 | 189篇 |
2010年 | 130篇 |
2009年 | 118篇 |
2008年 | 129篇 |
2007年 | 117篇 |
2006年 | 89篇 |
2005年 | 122篇 |
2004年 | 161篇 |
2003年 | 154篇 |
2002年 | 97篇 |
2001年 | 75篇 |
2000年 | 34篇 |
1999年 | 34篇 |
1998年 | 14篇 |
1997年 | 26篇 |
1996年 | 18篇 |
1995年 | 22篇 |
1994年 | 17篇 |
1993年 | 9篇 |
1992年 | 14篇 |
1991年 | 16篇 |
1990年 | 10篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 8篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1970年 | 3篇 |
1966年 | 3篇 |
1964年 | 4篇 |
1961年 | 3篇 |
排序方式: 共有3008条查询结果,搜索用时 15 毫秒
991.
Rafael Vicente de P��dua Ferreira Solange Kazumi Sakata Vera L��cia Keiko Isiki Hissae Miyamoto Maria Helena Bellini Luis Filipe C. P. de Lima J��lio Takehiro Marumo 《Environmental Chemistry Letters》2011,9(2):209-216
The present study investigated the influence of 241Am on microbial growth and the degradation of organic waste. Leachate samples collected in a lysimeter were periodically analyzed
for bacterial growth, under both aerobic and anaerobic conditions. 241Am inhibited bacterial growth, and the degradation of organic matter was delayed in comparison with the control. Minimal inhibitory
concentration assays and survival curves revealed that it inhibits the growth of Pseudomonas putida F1. The assay also revealed that 241Am is more toxic than 238U, Zn2+ and Cd2+. This study further led to the finding of four new radionuclide-tolerant bacterial strains: Flavobacterium spp., Pseudomonas gladioli, Chryseobacterium indologenes and Ochrobactrum anthropi. The survival curves of P. gladioli, C. indologenes revealed that these bacteria are resistant to metal as consortia. 相似文献
992.
da Silveira RP Rodrigues AP Santelli RE Cordeiro RC Bidone ED 《Environmental monitoring and assessment》2011,181(1-4):165-173
This study addressed the identification and monitoring of pollution sources of terrestrial origin in rivers (domestic sewage and industrial effluents) and critical fluvial segments in highly polluted environments under tidal influence (mixing marine and continental sources) from Guanabara Bay Basin, Rio de Janeiro, Brazil. The mass balance of contaminants was determined in conditions of continuous flow (low tide) during dry season (lower dilution capability). The results allowed the evaluation of the potential of contaminant mass generation by the different river segments and the estimation of their natural and anthropogenic components. The water quality of Igua?ú and Sarapuí Rivers were evaluated for metals and biochemical oxygen demand. The method gave an excellent response, including the possibility of sources identification and contaminated river segments ranking. The approach also offers fast execution and data interpretation, being highly efficient. 相似文献
993.
Nogueira L Rodrigues AC Trídico CP Fossa CE de Almeida EA 《Environmental monitoring and assessment》2011,180(1-4):243-255
Considering that diesel oil is one of the most common aquatic contaminants, we compare the oxidative stress between two species of fish with different habitats (Pterygoplichthys anisitsi, benthic and Oreochromis niloticus, nektonic) exposed to diesel oil. Malondialdehyde concentrations (MDA) and the activities of ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase were all analyzed in the fishes' livers and gills after 2 and 7 days of exposure to different concentrations of diesel (0.1 and 0.5 mL/L). In the tilapia, MDA levels and the activities of EROD and GST activity in the liver, as well as MDA levels and the activities of GST and SOD in the gill had statistically significant differences between the treatments and between the times of exposure. For the catfish, the same occurred in the case of MDA, EROD, and SOD in the liver and in CAT and SOD in the gills. There were significant differences in the enzyme activity and lipid peroxidation between the species. Although the activity of most enzymes seemed to be more expressive and responsive to diesel in O. niloticus, diesel oil also caused significant effects on oxidative stress parameters in P. anisitsi, even though this species is benthic and thus has less access to insoluble fractions of diesel oil. Therefore, both species can be used as sentinel organisms in environmental biomonitoring of diesel contamination. 相似文献
994.
Cristiane Rossi de Oliveira Luiz Augusto dos Santos Madureira 《Environmental monitoring and assessment》2011,173(1-4):91-105
Nonaromatic hydrocarbons and geochemical parameters from 17 sediment?Cwater interface samples were used to assess sources of organic matter in three harbors, located in Santa Catarina State, southern Brazil. The evaluation was based on the molar C/N/P ratios, abundance of resolved nonaromatic hydrocarbons (3.0?C25.9 ??g g???1), unresolved complex mixture, and two indexes: the carbon preference index (CPI) and the low molecular weight to high molecular weight ratio. The results indicate that the organic matter is predominantly of terrestrial origin (C/N > 10 and CPI > 2). Variations in the total organic carbon from 0.43 to 2.98 mmol g???1 and total phosphorus from 82.4 to 464.3 ??g g???1 showed no clear correlation with the silt and clay fractions of the sediments possibly due to anthropogenic input. In contrast to the low level of contamination based on the acyclic hydrocarbon distribution, the results obtained from a series of geologically stable hopanes and steranes reveal the presence of less degradable petroleum derivatives. 相似文献
995.
Peter Bröde Kalev Kuklane Victor Candas Emiel A. Den Hartog Barbara Griefahn Ingvar Holmér 《International journal of occupational safety and ergonomics》2013,19(2):231-244
The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments’ material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments. 相似文献
996.
997.
998.
Die geschichtliche Entwicklung der kosmologischen Modelle für den homogen–isotropen Kosmos, beginnend mit Alexander Friedmanns
epochalen Arbeiten (1922 und 1924) bis zur heutigen Diskussion aktueller Modelle wird dargestellt. Eine kardinale Rolle spielt
die offene Frage: Besteht die Materie des Kosmos zum weit überwiegenden Teil aus nicht–baryonischer (sog. exotischer) Dunkel–Materie
oder reicht die gesamte baryonische Materie aus, die aus den bekannten Atomen und Molekülen besteht, um die Entwicklung des
Kosmos zu verstehen. Auch von der normalen (baryonischen) Materie im Kosmos ist nur ein geringer Anteil (etwa 20 5 Prozent) in leuchtenden Objekten (Sterne, Gas, Staub) direkt beobachtbar. Im Abschnitt 3 wird der “Einstein–Limit” für
die kosmologische Konstante erl?utert und eine leicht einsichtige Herleitung des Zahlenwertes gegeben. 相似文献
999.
Raquel Barrena Gómez Felicitas Vázquez Lima Antoni Sánchez Ferrer 《Waste management & research》2006,24(1):37-47
Respiration is directly related to the metabolic activity of a microbial population. Micro-organisms respire at higher rates in the presence of large amounts of bioavailable organic matter while respiration rate is slower if this type of material is scarce. In the composting process respiration activity has become an important parameter for the determination of the stability of compost. It is also used for the monitoring of the composting process and it is considered an important factor for the estimation of the maturity of the material. A wide range of respirometric protocols has been reported based either on CO2 production, O2 uptake or release of heat. The most common methods are those based on O2 uptake. Respirometric assays are affected by a number of parameters including temperature, humidity, and both incubation and pre-incubation conditions. Results from respirometries are generally expressed as 'respiration indices', most of them with their own units and basis. In consequence, some confusion exists when referring and comparing respiration indices. This is particularly important because current and future legislations define and measure the biological stability of waste on the basis of respiration activity of the material. This paper discusses and compares most common respiration indices currently used. 相似文献
1000.