首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1775篇
  免费   82篇
  国内免费   283篇
  2140篇
  2023年   28篇
  2022年   33篇
  2021年   48篇
  2020年   54篇
  2019年   56篇
  2018年   47篇
  2017年   57篇
  2016年   53篇
  2015年   55篇
  2014年   71篇
  2013年   124篇
  2012年   48篇
  2011年   83篇
  2010年   58篇
  2009年   65篇
  2008年   86篇
  2007年   97篇
  2006年   81篇
  2005年   71篇
  2004年   76篇
  2003年   74篇
  2002年   65篇
  2001年   62篇
  2000年   63篇
  1999年   55篇
  1998年   56篇
  1997年   51篇
  1996年   35篇
  1995年   48篇
  1994年   45篇
  1993年   46篇
  1992年   31篇
  1991年   24篇
  1990年   27篇
  1989年   18篇
  1988年   5篇
  1987年   9篇
  1986年   5篇
  1985年   21篇
  1984年   18篇
  1983年   10篇
  1982年   9篇
  1981年   8篇
  1980年   9篇
  1979年   12篇
  1978年   9篇
  1977年   7篇
  1976年   8篇
  1975年   4篇
  1974年   8篇
排序方式: 共有2140条查询结果,搜索用时 15 毫秒
11.
12.
13.
Ito  Tadayoshi  Nakagiri  Akira 《Mycoscience》1994,35(4):413-415
In the course of study of fungi from soil, a new genus and species,Stellatospora terricola, was isolated. The fungus is distinguished from other known genera in having star- or comfit-shaped ascospores with a distinct germ pore. The morphological characters of the genus are considered to resemble those of the Sordariaceae in Ascomycotina.  相似文献   
14.
Biochemical profiles on API Rapid CH* strips and protein profiles on polyacrylamide gels in the presence of sodium dodecyl sulfate were used to distinguish two strains of the entomopathogenic fungusBeauveria bassiana (Balsamo) Vuillemin, ARSEF 2991 and ATCC 44860. Next, the toxicity of these two strains was determined at concentrations of 102, 104, 106 and 108 blastospores/ml on larvae of the Colorado potato beetleLeptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) and of its predator, the spotted ladybird beetle,Coleomegilla maculata lengi Timberlake (Coleoptera: Coccinellidae). Both strains were highly toxic toL. decemlineata larvae. However, the two strains exhibited different levels of toxicity forC. maculata larvae: ARSEF 2991 was toxic, whereas ATCC 44860 caused little coccinellid larval mortality.
Résumé Les profils biochimiques sur galeries API Rapid CH* et les profils protéiques sur gels de polyacrylamide ont été utilisés pour distinguer deux souches du champignon entomopathogèneBeauveria bassiana (Balsamo) Vuillemin. La toxicité de ces deux souches a été déterminée à des concentrations de 102, 104, 106 et 108 blastospores/ml sur des larves du doryphore,Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae) et de la coccinelle maculéeColeomegilla maculata lengi Timberlake (Coleoptera: Coccinellidae). Les deux souches deB. bassiana se sont avérées actives à l'égard des larves deL. decemlineata. Toutefois la souche ARSEF 2991 s'est avérée pathogène pour les larves deC. maculata, alors que la souche ATCC 44860 a provoqué une faible mortalité des larves.
  相似文献   
15.
A new species ofTalaromyces (Ascomycetes; Trichocomaceae) with aPenicillium anamorph,T. lagunensis, is described and illustrated. This fungus is characterized by its extremely restricted growh on Czapek-yeast extract agar, light yellow to light orange ascomata with a telaperidium, catenate, pyriform or ellipsoidal asci, ellipsoidal or subglobose ascospores with a microtuberculate wall, short conidiophores with an irregular, mostly monoverticillate to biverticillate penicillus, and subglobose to ovoid conidia. The holotype was isolated from forest soil in the Philippines.  相似文献   
16.
Pectic (carbonate-soluble, covalently-bound pectin, CBP) material stimulated increased ethylene production when vacuum-infiltrated into whole, mature green tomato ( Lycopersicon esculentum Mill. cv. Rutgers) fruit. Activity was greatest if CBP was extracted from mature green tomatoes with jellied locules. CBP extracted from mature green tomatoes with immature seeds had no elicitor activity, while CBP from turning or red ripe tomatoes was only moderately active. Infiltration of CBP from normal mature green fruit into ripening inhibitor ( rin ) mutant tomato fruit stimulated ethylene production and attenuated red pigmentation in these fruits. Partial purification of the active material was accomplished using DEAE-Sephadex and BioGel P-100 chromatography. The most highly purified fraction is comprised of neutral carbohydrate (95%) with a relatively low content of amino acids (1%) and a uronic acid content of less than 5%. This material may be an endogenous trigger of ethylene production and ripening.  相似文献   
17.
Two thermostable enzymes produced by the thermophilic fungus Paecilomyces varioti, a chitinase and laminarinase, were used to isolate protoplasts of a thermophilic fungus, Malbranchea sulfurea. The frequency of protoplast regeneration observed (35%) was considerably higher than that obtained using commercial lytic enzymes.  相似文献   
18.
A transposable element has been isolated from the industrially important fungus Aspergillus niger (strain N402). The element was identified as an insertion sequence within the coding region of the nitrate reductase gene. It had inserted at a TA site and appeared to have duplicated the target site upon insertion. The isolated element was found to be 4798 by in length and contained 37-bp inverted, imperfect, terminal repeats (ITRs). The sequence of the central region of the element revealed an open reading frame (designated ORF1) which showed similarity, at the amino acid level, to the transposase of the Tc1/mariner class of DNA transposons. Another sequence within the central region of the element showed similarity to the 3 coding and downstream untranslated region of the amyA gene of A. niger. Sequence homology and structural features indicate that this element, which has been named Ant1 (A. niger transposon 1), is related to the Tc1/mariner group of DNA transposons. Ant1 is apparently present as a single copy in strain N402 of A. niger.  相似文献   
19.
20.
Extracellular proteins from Botrytis cinerea CBS 144.55 were separated by use of isoelectric focusing in polyacrylamide gel and thin layer isoelectric focusing. In addition to the protein pattern, the activities of protease, amylase, cellulase, polygalacturonase, pectinesterase and glycosidases were determined.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号