全文获取类型
收费全文 | 3874篇 |
免费 | 37篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 88篇 |
废物处理 | 257篇 |
环保管理 | 324篇 |
综合类 | 432篇 |
基础理论 | 783篇 |
环境理论 | 7篇 |
污染及防治 | 1400篇 |
评价与监测 | 361篇 |
社会与环境 | 258篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 46篇 |
2022年 | 104篇 |
2021年 | 155篇 |
2020年 | 63篇 |
2019年 | 63篇 |
2018年 | 147篇 |
2017年 | 149篇 |
2016年 | 215篇 |
2015年 | 114篇 |
2014年 | 228篇 |
2013年 | 370篇 |
2012年 | 262篇 |
2011年 | 277篇 |
2010年 | 211篇 |
2009年 | 134篇 |
2008年 | 217篇 |
2007年 | 242篇 |
2006年 | 181篇 |
2005年 | 149篇 |
2004年 | 113篇 |
2003年 | 95篇 |
2002年 | 89篇 |
2001年 | 48篇 |
2000年 | 40篇 |
1999年 | 28篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 11篇 |
1995年 | 20篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1988年 | 3篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1982年 | 4篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1970年 | 2篇 |
1967年 | 4篇 |
1966年 | 4篇 |
1965年 | 2篇 |
1964年 | 5篇 |
1962年 | 3篇 |
1959年 | 4篇 |
1958年 | 15篇 |
1957年 | 5篇 |
1955年 | 2篇 |
排序方式: 共有3921条查询结果,搜索用时 31 毫秒
111.
Sinkings of fishing vessels, when accompanied by human loss, are accidents which lead to a great social upheaval, especially in the local area where they occur. In order to avoid or reduce these accidents, national governments must include in their legislation for this sector the appropriate safety measures. These resources and their distribution must be assigned in accordance with the needs of the accidentality, this requiring a detailed knowledge of the concentration of accidentality of a country’s fishing sector. In this context, the aim of the present work is twofold: first, to formulate a methodology for the fishing sector of a country, allowing the inequalities in the concentration of sinking accidents to be analysed; and second, to apply this methodology to the Spanish fishing fleet. Thus, two indices are constructed per region and type of fishing, for two variables: fishermen and vessels. Results are obtained both for the concentration of accidents and the associated Lorenz curves. An increase in the inequality in the spatial and functional distribution of these accidents is verified. 相似文献
112.
This paper aims to provide useful knowledge on the use of plastic wastes as additives to coking blends for the production of metallurgical coke. It focuses on the influence that the composition of plastic wastes has upon the development of coal fluidity, the generation of pressure during the coking process and the quality of the cokes produced in a semipilot oven. Several plastic mixtures of two types of thermoplastics, polyolefins (HDPE, LDPE and PP) and aromatic polymers such as PET, were used. The overall addition rate of plastics to a medium-fluid coal blend was 2 wt%. It is shown that polyolefins, weaker modifiers of coal fluidity, may be employed to maintain coke quality but that they have a negative effect on the generation of coking pressure, while plastics of the aromatic type such as PET, a strong modifier of coal fluidity, can be used to counteract the generation of coking pressure. From the results, it is deduced that the protocol developed is useful for determining the optimum amount of each type of polymer (polyolefins and aromatic polymers) that is needed in order to counteract the generation of pressure during the coking process and to maintain the quality of the cokes. 相似文献
113.
N. Said T. Bishara A. García-Maraver M. Zamorano 《Waste management (New York, N.Y.)》2013,33(11):2250-2256
Rice straw can be used as a renewable fuel for heat and power generation. It is a viable mean of replacing fossil fuels and preventing pollution caused by open burning, especially in the areas where this residual biomass is generated. Nevertheless, the thermal conversion of rice straw can cause some operating problems such as slag formation, which negatively affects thermal conversion systems. So, the main objective of this research is studying the combustion behavior of rice straw samples collected from various regions by applying thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). In addition, the thermal behavior of ashes from rice straw was also analyzed in order to detect their melting points, and ash sintering was detected at different temperatures within the range between 550 and 1000 °C. Since washing rice straw with water could reduce the content of undesirable inorganic compounds related to the ash fusibility, samples of washed rice straw were analyzed under combustion conditions to investigate its differences regarding the thermal behavior of rice straw. The results showed that rice straw washing led to a significant improvement in its thermal behavior, since it reduced the ash contents and sintering formation. 相似文献
114.
Jesús Barreiro-Hurlé María Espinosa-Goded Pierre Dupraz 《Journal of Environmental Planning and Management》2010,53(7):891-905
Agri-environmental schemes (AES) are the main policy instrument currently available in the EU to promote environmentally-friendly farming practices. However, the rate of adoption of these measures is still relatively low in southern Europe, and understanding how these rates can be increased is still an open issue. The goal of this paper is to increase that understanding by testing whether the factors which determine AES sign-up decisions are influenced by the intensity of change in farming practices that are brought about by adopting the scheme. A micro-economic model reflecting farmer AES sign-up decisions is proposed and applied to two schemes in Spain respectively requiring major or minor intensity of change in practices by surveying farmers eligible for both schemes. The results show that farm structural factors play a role when major practice change is required by the scheme, yet when dealing with minor change, individual farmer characteristics play a more determining role. Social capital and farmer attitude are important factors in both the AES surveyed. Therefore, it may be concluded that improving agronomic design would be an important tool to improve farmer participation in AES where major change is involved, whereas improved targeting and extension would help uptake for AES involving a lesser degree of change. 相似文献
115.
Fernanda Menezes França Teresa C. Brazil De Paiva Adriana S. Marcantônio Patrícia C. Teixeira Cláudia Maris Ferreira 《Journal of environmental science and health. Part. B》2013,48(6):406-410
The objective of this study was to determine the acute toxicity of some pesticides used in irrigated rice farming to Lithobates catesbeianus tadpoles. The LC50-96h for commercial formulations containing bentazon, penoxsulam, vegetable oil, permethrin and carbofuran, separately and their mixtures, were determined at the proportions commonly used in the field. The limits of risk concentrations of these products for the studied species were also established. The LC50-96h for tadpoles was 4,530 mg L?1 for bentazon; 7.52 mg L?1 for penoxsulam + 145.66 mg L?1 of vegetable oil; 81.57 mg L?1 for vegetable oil; 0.10 mg L?1 for permethrin; 29.90 mg L?1 for carbofuran (active ingredients), and 38.79 times the dose used in the field for the mixture of these products. The environmental risk was determined only for permethrin, and care should be taken when using the vegetable oil. 相似文献
116.
González-Santiago O Badillo-Castañeda CT Kahl JD Ramírez-Lara E Balderas-Renteria I 《Journal of the Air & Waste Management Association (1995)》2011,61(5):573-579
The Monterrey Metropolitan Area (MMA) is the third largest city in Mexico. Few studies have been carried out regarding its air pollution. The aim of this study was to analyze the temporal behavior of PM10 (particulate matter < or =10 microm in aerodynamic diameter). Data reported by the "Sistema Integral de Monitoreo Ambiental" (Integrated Environmental Monitoring System) network from 2006 to 2008 were used. PM10 levels were compared among the stations by year, season, and day of week. A bootstrap technique was used to obtain subsamples to which Student's t test and ANOVA were applied. PM10 levels were high and exceeded the annual limit of 50 microg/m3 set up by the Mexican standard Norma Oficial Mexicana NOM-025-SSA1-1993. These levels could have serious health effects. The southwest zone of MMA had the highest levels of PM10 during the period studied. Winter was the most polluted season, and summer was the least polluted season. Thursday and Friday were the most polluted days, and Sunday was the least polluted day. The hours with the highest levels of PM10 were 8:00 to 10:00 a.m., whereas nighttime hours were the cleanest. 相似文献
117.
Jiménez MA Martín-Valdepeñas JM García-Talavera M Martín-Matarranz JL Salas MR Serrano JI Ramos LM 《Journal of environmental radioactivity》2011,102(11):995-1007
In the frame of an epidemiological study carried out in the influence areas around the Spanish nuclear facilities (ISCIII-CSN, 2009. Epidemiological Study of The Possible Effect of Ionizing Radiations Deriving from The Operation of Spanish Nuclear Fuel Cycle Facilities on The Health of The Population Living in Their Vicinity. Final report December 2009. Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III, Consejo de Seguridad Nuclear. Madrid. Available from: http://www.csn.es/images/stories/actualidad_datos/especiales/epidemiologico/epidemiological_study.pdf), annual effective doses to public have been assessed by the Spanish Nuclear Safety Council (CSN) for over 45 years using a retrospective realistic-dose methodology. These values are compared with data from natural radiation exposure. For the affected population, natural radiation effective doses are in average 2300 times higher than effective doses due to the operation of nuclear installations (nuclear power stations and fuel cycle facilities). When considering the impact on the whole Spanish population, effective doses attributable to nuclear facilities represent in average 3.5 × 10−5 mSv/y, in contrast to 1.6 mSv/y from natural radiation or 1.3 mSv/y from medical exposures. 相似文献
118.
de la Flor María Patricia Camarillo Rafael Martínez Fabiola Jiménez Carlos Quiles Rafael Rincón Jesusa 《Environmental science and pollution research international》2021,28(19):23720-23730
Environmental Science and Pollution Research - For the photocatalytic degradation of antioxidant 2,6-di-tert-butyl-hydroxytoluene (BHT), several TiO2-based composites have been prepared in MWCNT... 相似文献
119.
Gómez-Tolosa María Rivera-Velázquez Gustavo Rioja-Paradela Tamara M. Mendoza-Cuenca Luis F. Tejeda-Cruz César López Sergio 《Environmental science and pollution research international》2021,28(2):1381-1396
Environmental Science and Pollution Research - The order Odonata has been regularly used as an indicator of the ecosystem’s condition. The objective of this review was to analyze the... 相似文献
120.
Aliste Marina Garrido Isabel Pérez-Lucas Gabriel Flores Pilar Hellín Pilar Navarro Simón Fenoll José 《Environmental science and pollution research international》2021,28(19):23849-23858
Environmental Science and Pollution Research - In this study, the photocatalytic degradation of four fungicides, myclobutanil, penconazole and difenoconazole (triazole compounds) and boscalid... 相似文献