全文获取类型
收费全文 | 46014篇 |
免费 | 2863篇 |
国内免费 | 5篇 |
出版年
2023年 | 273篇 |
2022年 | 244篇 |
2021年 | 603篇 |
2020年 | 549篇 |
2019年 | 559篇 |
2018年 | 1335篇 |
2017年 | 1157篇 |
2016年 | 1626篇 |
2015年 | 2242篇 |
2014年 | 2222篇 |
2013年 | 2967篇 |
2012年 | 3410篇 |
2011年 | 3100篇 |
2010年 | 2020篇 |
2009年 | 1553篇 |
2008年 | 2370篇 |
2007年 | 2355篇 |
2006年 | 2350篇 |
2005年 | 1955篇 |
2004年 | 1943篇 |
2003年 | 1733篇 |
2002年 | 1639篇 |
2001年 | 1067篇 |
2000年 | 1027篇 |
1999年 | 823篇 |
1998年 | 357篇 |
1997年 | 245篇 |
1996年 | 242篇 |
1995年 | 256篇 |
1994年 | 193篇 |
1993年 | 173篇 |
1992年 | 463篇 |
1991年 | 412篇 |
1990年 | 391篇 |
1989年 | 372篇 |
1988年 | 330篇 |
1987年 | 335篇 |
1986年 | 304篇 |
1985年 | 298篇 |
1984年 | 243篇 |
1983年 | 222篇 |
1982年 | 176篇 |
1979年 | 256篇 |
1974年 | 186篇 |
1973年 | 178篇 |
1972年 | 164篇 |
1971年 | 158篇 |
1970年 | 160篇 |
1969年 | 163篇 |
1968年 | 154篇 |
排序方式: 共有10000条查询结果,搜索用时 30 毫秒
991.
Cesar B. Ramírez-López Rita Beltrán-Sánchez Alistair Hernández-Izquierdo José Luis SalvadorHernández Eduardo Salcedo-Pérez Rosa E. del Río Mauro M. Martínez Pacheco 《Phyton》2021,90(3):907-920
This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis (Latreille). Plant deterrent agents act as repellents or antifeedants to prevent
wood decay and increase its useful life. The potential of the tree Caesalpinia coriaria (Fabaceae) as a biological
source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities. The gas chromatography-mass spectrometry analysis of the
leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were
determined. Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood
termite. Unlike the leaf essential oil, geraniol did not exhibit a repellency effect. An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of −7.5 Kcal/mol. Geraniol
interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol (negative control)
interacted with tryptophan 83 located adjacent to the active site. These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite.
However, they are an important natural control alternative. 相似文献
992.
Roberto Arredondo-Valdés Francisco D. Hernández-Castillo Mario Rocandio-Rodríguez Julia C. Anguiano-Cabello Madai Rosas-Mejía Venancio Vanoye-Eligio Salvador Ordaz-Silva Imelda V. López-Sánchez Laura D. Carrazco-Peña Julio C. Chacón-Hernández 《Phyton》2021,90(3):895-906
The tomato (Solanum lycopersicum L.) is one of the world’s most important vegetable crops. Still, phytopathogenic bacteria affect the yield and quality of tomato cultivation, like Agrobacterium tumefeciens (At), Clavibacter
michiganensis subsp. michiganensis (Cmm), Pseudomonas syringae pv. tomato (Pst), Ralstonia solanacearum (Rs),
and Xanthomonas axonopodis (Xa). Synthetic chemical products are used mostly on disease plant control, but
overuse generates resistance to bacterial control. This study aimed to evaluate the in vitro antibacterial activity
of the ethanolic extract of Moringa oleifera Lam. leaves against At, Cmm, Pst, Rs, and Xa, as well as information
about this plant species’ chemical composition. Antibacterial activity against pathogens observed by microplate
technique, phytochemical screening, and FTIR analysis revealed different bio-active compounds on ethanolic
extracts with antibacterial activity. The growth inhibition rate ranged between 0.08% and 99.94%. The inhibitory
concentration, IC50, required to inhibit 50% of At, Cmm, Pst, Rs, and Xa bacterial growth, was 276.67, 350.48,
277.85, 351.49, and 283.22 mg/L, respectively. Inhibition of phytopathogen bacteria’s growth increased as the concentrations of the extract also increased. Moringa oleifera extract can be recommended as a potent bio-bactericide. 相似文献
993.
994.
María Fátima Ladelfa Leticia Yamila Peche Gastón Ezequiel Amato Micaela Carolina Escalada Stefania Zampieri Franco Andrés Pascucci Andres Fernandez Benevento Dario Fernandez Do Porto Andrea Dardis Claudio Schneider Martin Monte 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2021,1868(7):119015
995.
Abdullah Mohib Sliwinska Elwira Góralski Grzegorz Latocha Piotr Tuleja Monika Widyna Patrycja Popielarska-Konieczna Marzena 《Plant Cell, Tissue and Organ Culture》2021,147(3):569-582
Plant Cell, Tissue and Organ Culture (PCTOC) - Endosperm, an ephemeral and storage tissue, serves as a source of nutrition and protection during embryo development and germination. It can be used... 相似文献
996.
Quero Gastón Bonnecarrère Victoria Simondi Sebastián Santos Jorge Fernández Sebastián Gutierrez Lucía Garaycochea Silvia Borsani Omar 《Photosynthesis research》2021,150(1-3):97-115
Photosynthesis Research - The photosynthesis process is determined by the intensity level and spectral quality of the light; therefore, leaves need to adapt to a changing environment. The incident... 相似文献
997.
Trentini Giulia E. Rojas Makarena Gajardo Daniela Alburquenque Débora Villagra Evelyn Gómez Aleydis Arru Laura Arencibia Ariel D. 《Plant Cell, Tissue and Organ Culture》2021,146(3):607-619
Plant Cell, Tissue and Organ Culture (PCTOC) - A biotechnological system for the production of plants biomass and phenylpropanoids of maqui was developed in photomixotrophic TIBs. The in vitro... 相似文献
998.
Lucho Simone Ribeiro do Amaral Marcelo Nogueira Milech Cristini Bianchi Valmor João Almagro Lorena Ferrer María Ángeles Calderón Antonio Asensio Braga Eugenia Jacira Bolacel 《Plant Cell, Tissue and Organ Culture》2021,146(1):171-184
Plant Cell, Tissue and Organ Culture (PCTOC) - Steviol glycosides (SGs) and gibberellins (GAs) share the same molecular basis. However, the coordination of their respective biosynthetic pathways is... 相似文献
999.
Domínguez-Gabriel Julio Guillén-Navarro Karina Otero-Colina Gabriel Valle-Mora Javier González-Gómez Rebeca 《Experimental & applied acarology》2021,85(1):1-17
Experimental and Applied Acarology - Tenuipalpid mites of the genus Brevipalpus are of significant economic and quarantine importance in agriculture. They can damage and vector phytopathogenic... 相似文献
1000.