全文获取类型
收费全文 | 827篇 |
免费 | 102篇 |
国内免费 | 292篇 |
出版年
2024年 | 7篇 |
2023年 | 38篇 |
2022年 | 54篇 |
2021年 | 62篇 |
2020年 | 68篇 |
2019年 | 71篇 |
2018年 | 46篇 |
2017年 | 55篇 |
2016年 | 48篇 |
2015年 | 48篇 |
2014年 | 60篇 |
2013年 | 79篇 |
2012年 | 46篇 |
2011年 | 51篇 |
2010年 | 46篇 |
2009年 | 73篇 |
2008年 | 32篇 |
2007年 | 60篇 |
2006年 | 44篇 |
2005年 | 40篇 |
2004年 | 32篇 |
2003年 | 24篇 |
2002年 | 16篇 |
2001年 | 16篇 |
2000年 | 30篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有1221条查询结果,搜索用时 15 毫秒
481.
482.
Improved Phytophthora resistance in commercial chickpea (Cicer arietinum) varieties negatively impacts symbiotic gene signalling and symbiotic potential in some varieties
下载免费PDF全文
![点击此处可从《Plant, cell & environment》网站下载免费的PDF全文](/ch/ext_images/free.gif)
483.
斑玉蕈Hypsizygus marmoreus是我国重要的工厂化栽培食用菌之一,在栽培过程中发生污染将为生产企业带来经济损失。为对实际生产中的斑玉蕈病害进行溯源和防控,本研究采集了一家大型生产企业在3个不同省市产地发生污染的菌种或子实体样品,结合分子测序和形态特征观察对分离到的微生物进行鉴定,并通过平板对峙实验分析了菌株对斑玉蕈菌丝生长的影响。从样品中共分离得到了11株可疑致病微生物,包含10株细菌和1株真菌,分布于3个科7个属,优势科为肠杆菌科Enterobacteriaceae,优势属为芽胞菌属Bacillus,其中2株细菌可能分别为芽孢杆菌属和肠杆菌属Enterobacter新种。对峙实验显示7株细菌和1株真菌对相应宿主斑玉蕈菌株的菌丝生长有明显的抑制作用。结合生产过程,提出培养料的配制、灭菌和出菇管理阶段是斑玉蕈栽培中预防病害的3个关键控制点。在秋冬季气温较低时适当延长培养料的灭菌升温时间,在夏季菇房需要设备降温时加强对出菇过程中栽培环境尤其是水体的严格管理,有助于降低斑玉蕈工厂化栽培的病害发生率。 相似文献
484.
不同土地利用方式下喀斯特峰丛洼地土壤微生物群落特征 总被引:7,自引:0,他引:7
基于对喀斯特峰丛洼地6种土地利用类型(坡耕地、草丛、灌丛、人工林、次生林、原生林)的土壤微生物、养分、矿物质和植被4组变量35个指标的调查分析,研究了不同土地利用方式下土壤微生物种群数量、微生物生物量C、N、P及其分形特征,以及土壤微生物与植被、土壤养分、矿物质的关系.结果表明:不同土地利用方式下喀斯特峰丛洼地的土壤微生物种群数量及组成不同.微生物种群数量均以原生林和坡耕地最高,人工林最低;3种森林土壤的细菌比率较大,坡耕地、草丛、灌丛的放线菌比率较大,真菌的比率均很小;土壤微生物生物量C、N、P的含量均很高,其中原生林最高;土壤微生物生物量碳与土壤微生物种群数量具有良好的分形关系,而土壤微生物生物量氮、磷与种群数量不存在分形关系;土壤微生物与植被、土壤养分、土壤矿物质显著相关,其中土壤微生物生物量碳与乔木层的Shannon指数、土壤速效氮、Fe2O3、CaO含量显著相关. 相似文献
485.
486.
《Journal of Plant Interactions》2013,8(2):81-92
Abstract Laser Microdissection (LM) is a technology that allows the rapid procurement of selected cell populations from a section of heterogeneous tissues in a manner conducive to the extraction of DNA, RNA, proteins and even metabolites. In the past few years, it has also been applied to plant biology in order to study gene expression in plant-nematode and plant-microbe interactions. LM represents a powerful tool since cells associated with a particular infection stage can be visualized under the microscope and harvested. Therefore, verification of the response of the plant during the progression of the colonization can be performed in different cell types. Applications of LM to study the interaction between the plant and both pathogenic and symbiotic organisms (i.e. nematode and fungi, respectively) are explored in this review. 相似文献
487.
488.
STRUCTURE-ACTIVITY RELATIONSHIPS OF OLIGOAGAR ELICITORS TOWARD GRACILARIA CONFERTA (RHODOPHYTA) 总被引:1,自引:0,他引:1
Florian Weinberger Christophe Richard Bernard Kloareg Yoel Kashman Hans-Georg Hoppe Michael Friedlander 《Journal of phycology》2001,37(3):418-426
Agar oligosaccharides in the neoagarobiose series were prepared by partial enzyme hydrolysis, separated on Biogel P2 and P4, and analyzed by high-performance anion exchange chromatography with pulsed amperometric detection, yielding neoagarosaccharide fractions with a disaccharide repetition degree ranging from 1 (neoagarobiose) to more than 8 (neoagarohexadecaose). These fractions were analyzed for their biological activity toward the marine red alga Gracilaria conferta (Schousboe ex Montagne) J. et G . Feldmann in terms of increase of oxygen consumption, release of hydrogen peroxide, elimination of epiphytic bacteria, and induction of thallus tip bleaching. The structure–activity and dose–response relationships of neoagarosaccharides were very similar in the respiratory and oxidative burst responses and in their bactericidal properties, with neoagarosaccharides consisting of 6 to 8 disaccharide repeating units being the most active. All these responses were competitively inhibited by the reduced form of neoagarohexaose, neoagarohexaitol. In contrast, the tip-bleaching response was light dependent, required much higher concentrations of neoagarosaccharides, and was not inhibited by neoagarohexaitol, suggesting that it is an unspecific oxidative stress reaction. Putative structural effects on the recognition of endogenous agar-oligosaccharide elicitors by G. conferta are discussed. 相似文献
489.
本试验旨在研究不同剩余采食量(residual feed intake, RFI)相关肉牛胃肠道微生物物种组成及相对丰度、微生物基因功能注释与富集特征。选取30头牛进行81 d饲喂试验,试验结束后选取极端RFI个体各5头屠宰并采集瘤胃液及肠道末端粪便样用于宏基因组测序。结果表明:共获得259 045.47 Mb有效数据,组装得到 4 318 393条Scaftigs,基因预测得到7 008 053个开放阅读框(ORFs)。进行物种注释后发现粪便样中Top10物种相对丰度在高剩余采食量(high residual feed intake, HRFI)、低剩余采食量(low residual feed intake, LRFI)组间无差异(P>0.05),瘤胃液中的Top10微生物在LRFI组的相对丰度均低于HRFI组;粪便中、瘤胃液中优势菌门均为拟杆菌门和厚壁菌门;粪便中的优势属为拟杆菌属,瘤胃液中的优势属为普雷沃菌属。LefSe分析显示,在粪便中LRFI组的丹毒丝菌纲(Erysipelotrichia)显著富集(P<0.05),瘤胃液中差异最显著的是甲烷杆菌纲(Methanobacteria),且该菌在HRFI组的相对丰度显著高于LRFI组(P<0.05)。使用KEGG、eggNOG和CAZy数据库进行功能注释分析表明,在胃肠道中微生物的一些功能基因的丰度与RFI的分组有关。不同RFI肉牛瘤胃液、粪便中的微生物结构存在显著差异,丹毒丝菌纲、甲烷杆菌纲可能是区分肉牛饲料效率的潜在生物标志物之一。 相似文献
490.
Cell suspensions of H2/CO2-grown Sporomusa termitida catalyzed an H2-supported synthesis of acetate from CO2 at rates of about 1 mol acetate x h-1 x mg protein-1. Cells pre-grown on methanol, mannitol, lactate, or glycine also displayed H2-supported acetogenesis from CO2, although at rates 5–85% that of H2/CO2-grown cells. With methanol-grown cell suspensions: the presence of methanol greatly stimulated the rate of H2-supported conversion of 14CO2 to 14C-acetate (which became labeled mainly in the COOH-group); and like-wise the presence of H2 stimulated the conversion of 14CH3OH+CO2 to 14C-acetate (which became labeled mainlyan the CH3-group). Analogous stimulatory effects were observed for cell suspensions pre-grown on methanol + CO2+H2. Furthermore, when H2 (+CO2) was included as a growth substrate with either methanol or lactate: both substrates were used simultaneously; there was no diauxie in the growth of cells or in acetate production; and the molar growth yield of S. termitida was close to that predicted from summation of the yields observed when grown with each substrate alone. These data indicated that S. termitida can grow by mixotrophy, i.e. by the simultaneous use of H2/CO2 and organic compounds for energy. Results are discussed in light of the ability of H2/CO2 acetogens to outprocess methanogens in H2 consumption in the hindgut fermentation of wood-feeding termites. 相似文献