全文获取类型
收费全文 | 1698篇 |
免费 | 131篇 |
专业分类
林业 | 176篇 |
农学 | 72篇 |
基础科学 | 20篇 |
475篇 | |
综合类 | 62篇 |
农作物 | 89篇 |
水产渔业 | 158篇 |
畜牧兽医 | 566篇 |
园艺 | 33篇 |
植物保护 | 178篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 24篇 |
2021年 | 44篇 |
2020年 | 52篇 |
2019年 | 43篇 |
2018年 | 83篇 |
2017年 | 66篇 |
2016年 | 67篇 |
2015年 | 74篇 |
2014年 | 72篇 |
2013年 | 120篇 |
2012年 | 143篇 |
2011年 | 129篇 |
2010年 | 80篇 |
2009年 | 65篇 |
2008年 | 118篇 |
2007年 | 81篇 |
2006年 | 91篇 |
2005年 | 88篇 |
2004年 | 84篇 |
2003年 | 71篇 |
2002年 | 54篇 |
2001年 | 38篇 |
2000年 | 28篇 |
1999年 | 35篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 4篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1829条查询结果,搜索用时 203 毫秒
111.
Pimenta BV Haddad CF Nascimento LB Cruz CA Pombal JP 《Science (New York, N.Y.)》2005,309(5743):1999; author reply 1999
112.
113.
Observations of internal wave velocity fluctuations show that enhanced turbulent mixing over rough topography in the Southern Ocean is remarkably intense and widespread. Mixing rates exceeding background values by a factor of 10 to 1000 are common above complex bathymetry over a distance of 2000 to 3000 kilometers at depths greater than 500 to 1000 meters. This suggests that turbulent mixing in the Southern Ocean may contribute crucially to driving the upward transport of water closing the ocean's meridional overturning circulation, and thus needs to be represented in numerical simulations of the global ocean circulation and the spreading of biogeochemical tracers. 相似文献
114.
115.
Sampedro I Aranda E Rodríguez-Gutiérrez G Lama-Muñoz A Ocampo JA Fernández-Bolaños J García-Romera I 《Journal of agricultural and food chemistry》2011,59(7):3239-3245
Byproducts generated from food industries, such as olive oil mills, have been studied to decrease harmful pollution and their environmental consequences. In this work, a new thermal pretreatment and saprobic fungal incubation to detoxify alperujo (two-phase olive mill waste) have been evaluated in view of its use as fertilizer in agriculture. The sequential use of both methods simplifies the thermal conditions and incubation times of the fungal treatment. Optimization of the thermal treatment from 150 to 170 °C for 45 and 15 min, respectively, reduced the incubation time with Coriolpsis rigida from 20 to 10 weeks needed to reduce phytotoxic effects on tomato plants. Therefore, the combination of thermal and biological treatments will allow the development of the potential benefits of alperujo to improve nutrients in agricultural soil. 相似文献
116.
Hurtado-Fernández E Carrasco-Pancorbo A Fernández-Gutiérrez A 《Journal of agricultural and food chemistry》2011,59(6):2255-2267
A powerful HPLC-DAD-ESI-TOF MS method was established for the efficient identification of the chemical constituents in the methanolic extracts of avocado (Persea americana). Separation and detection conditions were optimized by using a standard mix containing 39 compounds belonging to phenolic acids and different categories of flavonoids, analytes that could be potentially present in the avocado extracts. Optimum LC separation was achieved on a Zorbax Eclipse Plus C18 analytical column (4.6×150 mm, 1.8 μm particle size) by gradient elution with water+acetic acid (0.5%) and acetonitrile as mobile phases, at a flow rate of 1.6 mL/min. The detection was carried out by ultraviolet-visible absorption and ESI-TOF MS. The developed method was applied to the study of 3 different varieties of avocado, and 17 compounds were unequivocally identified with standards. Moreover, around 25 analytes were tentatively identified by taking into account the accuracy and isotopic information provided by TOF MS. 相似文献
117.
118.
119.
Verardo V Arraez-Roman D Segura-Carretero A Marconi E Fernandez-Gutierrez A Caboni MF 《Journal of agricultural and food chemistry》2011,59(14):7700-7707
Nowadays there is considerable interest in the consumption of alternative crops as potential recipes for gluten-free products production. Therefore, the use of buckwheat for the production of gluten-free pasta has been investigated in the present study. RP-HPLC-ESI-TOF-MS has been applied for the separation and characterization of free and bound phenolic compounds in buckwheat flour and buckwheat spaghetti. Thus, 32 free and 24 bound phenolic compounds in buckwheat flour and spaghetti have been characterized and quantified. To the authors' knowledge, protochatechuic-4-O-glucoside acid and procyanidin A have been detected in buckwheat for the first time. The results have demonstrated a decrease of total free phenolic compounds from farm to fork (from flour to cooked spaghetti) of about 74.5%, with a range between 55.3 and 100%, for individual compounds. The decrease in bound phenols was 80.9%, with a range between 46.2 and 100%. The spaghetti-making process and the cooking caused losses of 46.1 and 49.4% of total phenolic compounds, respectively. Of the total phenolic compounds present in dried spaghetti, 11.6% were dissolved in water after cooking. 相似文献
120.
Colomer I Aguado P Medina P Heredia RM Fereres A Belda JE Viñuela E 《Pest management science》2011,67(10):1237-1244
BACKGROUND: Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) are among the most serious pests of sweet peppers in greenhouses. Chemical control is difficult because of their high reproductive rates and insecticide resistance, and seasonal inoculative releases of Orius laevigatus (Fieber) and Amblyseius swirskii (Athias‐Henriot) are commonly used to reduce their populations. As chemical treatments are often needed in the crop against other pests, the side effects of methoxyfenozide (an insect growth regulator against lepidopteran pests) and flonicamid (a selective feeding inhibitor against sucking insects) were studied in both beneficial organisms in a commercial greenhouse. RESULTS: Orius laevigatus and A. swirskii were released at commercial rates (4–5 and 100 m?2), and a strong establishment and a very homogeneous distribution were reached. One pesticide treatment with the maximum field recommended concentration of methoxyfenozide and flonicamid (96 and 100 mg AI L?1) was done when they were well established, and their population levels were not affected either immediately or up to 30 days after treatment. CONCLUSION: The results are indicative of no impact of methoxyfenozide and flonicamid on the two natural enemies in the field, and both can be considered as potential alternatives to be included in IPM programmes in sweet pepper. Copyright © 2011 Society of Chemical Industry 相似文献