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   473篇
  免费   25篇
  2023年   3篇
  2022年   13篇
  2021年   22篇
  2020年   13篇
  2019年   11篇
  2018年   23篇
  2017年   16篇
  2016年   21篇
  2015年   22篇
  2014年   26篇
  2013年   25篇
  2012年   56篇
  2011年   32篇
  2010年   26篇
  2009年   23篇
  2008年   36篇
  2007年   27篇
  2006年   16篇
  2005年   14篇
  2004年   12篇
  2003年   14篇
  2002年   8篇
  2001年   12篇
  2000年   4篇
  1999年   6篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1986年   1篇
  1981年   2篇
  1975年   1篇
  1973年   1篇
排序方式: 共有498条查询结果,搜索用时 265 毫秒
1.
Identification of different protein functions facilitates a mechanistic understanding of Japanese encephalitis virus (JEV) infection and opens novel means for drug development. Support vector machines (SVM), useful for predicting the functional class of distantly related proteins, is employed to ascribe a possible functional class to Japanese encephalitis virus protein. Our study from SVMProt and available JE virus sequences suggests that structural and nonstructural proteins of JEV genome possibly belong to diverse protein functions, are expected to occur in the life cycle of JE virus. Protein functions common to both structural and non-structural proteins are iron-binding, metal-binding, lipid-binding, copper-binding, transmembrane, outer membrane, channels/Pores - Pore-forming toxins (proteins and peptides) group of proteins. Non-structural proteins perform functions like actin binding, zinc-binding, calcium-binding, hydrolases, Carbon-Oxygen Lyases, P-type ATPase, proteins belonging to major facilitator family (MFS), secreting main terminal branch (MTB) family, phosphotransfer-driven group translocators and ATP-binding cassette (ABC) family group of proteins. Whereas structural proteins besides belonging to same structural group of proteins (capsid, structural, envelope), they also perform functions like nuclear receptor, antibiotic resistance, RNA-binding, DNA-binding, magnesium-binding, isomerase (intra-molecular), oxidoreductase and participate in type II (general) secretory pathway (IISP).  相似文献   
2.
The dominant bacteriaPseudomonas sp. andArthrobacter sp. were isolated from the standing water of carbofuran-retreatedAzolla plot.Arthrobacter sp. hydrolysed carbofuran added to the mineral salts medium as a sole source of carbon and nitrogen while no degradation occurred withPseudomonas sp. Interestingly, when the medium containing carbofuran was inoculated with bothArthrobacter sp. andPseudomonas sp., a synergistic increase in its hydrolysis and subsequent release of CO2 from the side chain was noticed. This synergistic interaction was better expressed at 25° C than at 35° C. Likewise, related carbamates, carbaryl, bendiocarb and carbosulfan were more rapidly degraded in the combined presence of both bacterial isolates.  相似文献   
3.
Experiments were conducted to determine optimum stocking density for Clarias batrachus larvae and fry during hatchery rearing. The increase in stocking density decreased the total weight, specific growth rate (SGR) and percent weight gain of Clarias larvae during a 13‐day experiment. Survival rate was highest at a stocking density of 1000 m?2 and lowest at 5000 m?2. Stocking density did not influence the total biomass production of larvae. Clarias batrachus fry performance was studied during a 28‐day hatchery rearing experiment whereby fry stocked at a density of 100 m?2 attained the highest total body weight (P < 0.05). The survival rate greatly declined to 59–61% by a density increase to 300 m?2 and above. Stocking density influenced growth and survival of C. batrachus larvae and fry during hatchery rearing. The best performance was obtained when larvae were stocked at 2000 m?2; survival was highest with C. batrachus fry stocked at 200 m?2.  相似文献   
4.
There is a growing interest to find alternate bioresources for production of ethanol, apart from cane/sugar beet molasses and starchy crops like sweet sorghum, cassava and sweet potato. Mahula (Madhuca latifolia L.) is a forest tree abundantly available in the Indian subcontinent and its flowers are very rich in fermentable sugars (28.1-36.3 g 100 g(-1)). Batch fermentation of fresh and 12-month-stored flowers with free (whole cells) and immobilized cells of Saccharomyces cerevisiae (strain CTCRI) was carried out in 2-l Erlenmeyer flasks. The ethanol yields were 193 and 148 g kg(-1) (using free cells) and 205 and 152 g kg(-1) (using immobilized cells) from fresh and 12-month-stored mahula flowers, respectively.  相似文献   
5.
Nanocomposite thin films consisting of Cu nanoparticles embedded in silica matrix were synthesized by atom beam co-sputtering technique. Plasmonic, optical, and structural properties of the nanocomposite films were investigated by using ultraviolet (UV)–visible absorption spectroscopy, nonlinear optical transmission, X-ray diffraction (XRD), and low-frequency Raman scattering. UV–visible absorption studies revealed the surface plasmon resonance absorption at 564 nm which showed a red shift with increase in Cu fraction. XRD results together with surface plasmon resonance absorption confirmed the presence of Cu nanoparticles of different size. Low-frequency Raman studies of nanocomposite films revealed breathing modes in Cu nanoparticles. Nanocomposites with lower metal fractions were found to behave like optical limiters. The possibility of controllably tuning the optical nonlinearity of these nanocomposites could enable them to be the potential candidates for applications in nanophotonics.  相似文献   
6.
Newcastle disease (ND) is highly contagious, economically important viral disease affecting most of avian species worldwide. Newcastle disease virus (NDV) has single stranded negative sense RNA genome which encodes for six structural and two non-structural proteins. Envelope glycoproteins i.e. hemagglutinin-neuraminidase (HN) and the fusion (F), elicit protective immune response. In this study, HN and F genes of velogenic (virulent) strain were amplified and cloned at multiple cloning sites A and B, respectively into pIRES bicistronic vector for use as bivalent DNA vaccine against ND. The recombinant plasmid was characterized for its orientation by restriction enzyme digestion and PCR. Expression of HN and F genes was assessed in transfected Vero cells at RNA level using RT-PCR in total RNA as well as protein level using IFAT, IPT and western blot using NDV specific antiserum. All these experiments confirmed that HN and F genes cloned in recombinant pIRES.nd.hn.f are functionally active. The recombinant construct is being evaluated as DNA vaccine against ND.  相似文献   
7.
8.
Abstract In this study, the recognition contour of Chemosensor 1 was investigated using semiaqueous methanol (XH, mole fraction = 0.31) for a range of anions and bioactive species. Host–receptor signalling based on the internal charge transfer mechanism for Chemosensor 1 was explored and reported. Structure of Chemosensor 1 and its plausible anion coordination based on hydrogen bonding is complemented with density functional theory. Consequently, we investigated the applicability of the synthesized probe in blood plasma, urine, tap water samples, and for monitoring of ATP in lysosomes by apyrase enzyme.  相似文献   
9.
The International Journal of Life Cycle Assessment - Napier grass, one of the high yield perennial energy crops can be grown on marginal lands with minimal inputs, but with increased soil carbon...  相似文献   
10.
The International Journal of Life Cycle Assessment - Producing biochar from forest residues can help resolve environmental issues by reducing forest fires and mitigating climate change. However,...  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