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991.
The early stage of plant–rhizobacteria interaction, affected by plant root exudates and plant–rhizobacteria surface contact,
is considered to be critical for plant growth-promoting rhizobacteria colonizing plant roots and initiating the beneficial
effects on plant growth. However, little is known about the mechanisms of plant–rhizobacteria surface contact involved in
early stage of plant–rhizobacteria interaction. In order to reveal the molecular mechanisms of the surface contact, a rhizobacterium
Bacillus
amyloliquefaciens B55 was interacted with plant roots of rice R109 and used to perform a cDNA-based suppression-subtractive hybridization.
Seven differentially expressed DNA fragments were identified. Except for the two fragments showing no matches to any known
sequences in the Genbank, the other five fragments were found to have high homologies with the genes encoding 2-oxoglutarate
dehydrogenase E1 component OdhA, aspartate ammonia-lyase AnsB, and hypothetical protein proposed to be involved in surface
adhesion, acetolactate decarboxylase AlsD, and DNA mismatch repair protein MutL, respectively. The induced RNA expression
levels of two putative genes ansB and odhA and an unmatched DNA fragment BD33 were verified by RT-PCR analysis. 相似文献
992.
Yan Wang Wan-Sheng Chen Zhi-Jun Wu Zhong-Xin Xi Wei Chen Gui-Jun Zhao Xia Li Lian-Na Sun 《Biochemical Systematics and Ecology》2011
The present phytochemical investigation on Salacia amplifolia led to the isolations of 13 triterpenes, including quinonemethides, friedelanes, oleananes and ursanes triterpenes, three simple phenolics, one polyol and one chromanone. All of them were isolated from this plant for the first time. The presences of quinonemethide triterpenoids might be employed as the common characteristic constituents of both Hippocrateaceae and Celastraceae families. 相似文献
993.
994.
Until the end of last century, scientists began to show their concern about greenhouse gas emission from reservoirs and questioned the “green credential” of hydroelectric dams since then. Through measurements along the channel of the TGR, an unexpectedly low CH4 emission rate was recently observed from the surface of the TGR, much lower than our assumed estimate before. Moreover, the rate from the TGR is lower than that from many hydroelectric reservoirs. One possible reason for such a low emission rate is that lack of substrates supplied by decomposed vegetation limits the CH4 production in the sediment of the TGR because of vegetation clearance since 2002 before impounding, whose primary purpose is to conserve the water quality. These results indicated that TGR is not a hotspot of CH4 emission. On a broader sense, it also indicated that removal of flooded vegetation would help to decrease CH4 emission from dam reservoirs before impounding, especially in the drawdown area. 相似文献
995.
Zebrafish eggs used as bioreactors for the production of bioactive tilapia insulin-like growth factors 总被引:1,自引:0,他引:1
Shao-Yang Hu Chia-Hsuan Liao Yi-Pei Lin Yen-Hsing Li Hong-Yi Gong Gen-Hwa Lin Koichi Kawakami Tzu-Hsuan Yang Jen-Leih Wu 《Transgenic research》2011,20(1):73-83
Multiple advantages-including the short generation time, large numbers of fertilized eggs, low cost of cultivation and easy
maintenance favor the use of fish as bioreactors for the production of pharmaceutical proteins. In the present study, zebrafish
eggs were used as bioreactors to produce mature tilapia insulin-like growth factors (IGFs) proteins using the oocyte-specific
zona pellucida (zp3) promoter. The chimeric expression plasmids, pT2-ZP-tIGFs-IRES-hrGFP, in which hrGFP was used as reporter of tilapia IGFs
expression, were designed to established Tg (ZP:tIGFs:hrGFP) transgenic lines for the expression of tilapia IGF-1 and IGF-2. Recombinant tilapia IGF-1 and IGF-2 were expressed as soluble
forms in cytoplasm of fertilized eggs. The content level of tilapia IGF-1 and IGF-2 were 6.5 and 5.0% of the soluble protein,
respectively. Using a simple Ni–NTA affinity chromatography purification process, 0.58 and 0.49 mg of purified tilapia IGF-1
and IGF-2 were obtained, respectively, from 650 fertilized eggs. The biological activity of the purified tilapia IGF-1 and
IGF-2 was confirmed via a colorimetric bioassay to monitor the growth stimulation of zebrafish embryonic cells (ZF4), tilapia
ovary cells (TO-2) and human osteosarcoma epithelial cells (U2OS). These results demonstrate that the use of zebrafish eggs
as bioreactors is a promising approach for the production of biological recombinant proteins. 相似文献
996.
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999.
Shuo-yu Charlotte Wu 《Biosemiotics》2011,4(3):309-330
Translation has long been viewed as ‘code-switching’ either within or between languages. Hence, most translation discussions
center on its linguistic and cultural aspects. However, the fundamental mechanism of ‘translation as interpretative semiosis’
has yet to be studied with appropriate rigor. Susan Petrilli (2008) has identified ‘iconicity’ as the key that enables translative semiosis. Nevertheless, as her model is restricted to a discussion
of literary translation activity in verbal sign systems, a fundamental mechanism to explain translation as interpretative
semiosis is still needed. By analyzing the interactions between the source sign (the translated) and the target sign (the
translatant) in the translating process, it can be discerned that Humberto Maturana’s notion of autopoiesis may provide some
crucial insights into translative semiosis. By identifying the autopoietic nature of translation, that is, the interlocked
structural coupling between the Translated and Translatant, translation is no longer the ‘one-to-one-correspondence’ between
sign systems, but rather a recursive process of interpretation—an interpretive semiosis. Moreover, it is by this autopoietic,
self-productive mechanism of translation that I would suggest translation becomes a recursive generation of new inter-connections
between semiotics systems. 相似文献
1000.