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181.
Ryan B. Mounce Susan A. O’Shaughnessy Brock C. Blaser Paul D. Colaizzi Steven R. Evett 《Irrigation Science》2016,34(3):231-244
In the High Plains, corn (Zea mays L.) is an important commodity for livestock feed. However, limited water resources and drought conditions continue to hinder corn production. Drought-tolerant (DT) corn hybrids could help maintain high yields under water-limited conditions, though consistent response of such hybrids is unverified. In this two-year study, the effects of three irrigation treatments were investigated for a DT and conventional maize hybrid, Pioneer AQUAMax P0876HR and Pioneer 33Y75, respectively. In 2013, the drier of the 2 years, irrigation amounts and crop water use (ETc) were greater for the conventional hybrid, but grain water use efficiency (WUE) and harvest index were significantly greater for the DT hybrid. In 2014, grain yields and WUE were not significantly different between hybrids. However, irrigation amounts, ETc and biomass yields were greater for the conventional hybrid. Results from both years indicate that the DT hybrid required less water to maximize grain yield as compared to the conventional hybrid. Producing relatively high yields with reduced amounts of water may provide a means for producers to continue corn production in a semiarid environment with declining water supplies. 相似文献
182.
Tae Hwan Jun Min Ji Kim Sungyoun Kim Young Hwa Jung Hak-Ryong Moon Kwang-Soo Kim 《Water, air, and soil pollution》2017,228(3):110
Activated carbon-coated electrode was developed and applied in electrostatic precipitator to remove volatile organic compound gases simultaneously with dust particles from a contaminated air. The activated carbon coating mixture was made up of powdered activated carbon (AC), carbon black (CB), and polyvinyl acetate (PVA), and methanol was added as a solvent to control the thickness of the mixture for best coating performance. During the coating process, the Brunauer-Emmett-Teller (BET) surface decreased to 86% of the original AC while pore volume percentages of macro pore increased, compared to micro- and meso-sized pores. The adsorption isotherm of benzene, toluene, ethyl benzene, and xylene (BTEX) gases onto the original AC and AC coating mixture (AC thoroughly mixed with PVA and methanol for coating and powdered again after dry) were tested and compared to each other, and it was found that both isotherm were best fitted to Freundlich and Langmuir isotherm with the order of adsorption capacities; ethyl benzene?>?m-xylene?>?toluene?>?benzene. The difference between adsorption capacities was clearer with the absorbent AC but became little with the AC coating mixture. In removing BTEX at increasing linear velocities up to 6.7 cm/s, it appeared that the surface area of AC electrode was directly proportional to its removal rate of BTEX. The thermal desorption was applied to regenerate the AC electrode, and 200 °C was found to be most efficient for benzene desorption, but higher temperature would be required for entire BTEX gases desorption. 相似文献
183.
Defeng Zhang Xiaoli Ke Lihui Liu Maixin Lu Cunbin Shi Zhigang Liu 《Aquaculture International》2018,26(3):885-897
Several outbreaks of Streptococcus agalactiae infection of bighead carp (Aristichthys nobilis) were observed in China. The molecular epidemiology and pathogenicity of S. agalactiae in bighead carp and tilapia (Oreochromis sp.) is poorly understood. In the present study, we identified S. agalactiae strains isolated from diseased bighead carp using the API 20 Strep kit and 16S rDNA sequencing and determined whether these strains came from tilapia. Of the 46 identified S. agalactiae strains, 24 strains were successfully isolated from diseased bighead carps, 20 S. agalactiae strains were isolated from tilapia, and two S. agalactiae strains were isolated from tiger frog (Hoplobatrachus chinensis). The results of molecular typing, including multilocus sequence typing, molecular serotyping, surface protein gene detection, and virulence-related gene detection showed that the 44 strains from bighead carp and tilapia were highly similar, whereas different from tiger frog GBS strains. Remarkably, the bighead carp strain Hn1404 showed high virulence in bighead carp and zebrafish. Moreover, this strain was pathogenic to Nile tilapia (Oreochromis niloticus). In addition, comparative genomic analysis showed that isolate Hn1404 had a close relationship with the bighead carp and tilapia S. agalactiae strains. All the analyses of the genetic characteristics of bighead carp and tilapia strains showed that tilapia S. agalactiae strains could be transmitted to other fish species such as bighead carp. 相似文献
184.
Custódio L Escapa AL Fernandes E Fajardo A Aligué R Alberício F Neng N Nogueira JM Romano A 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(1):78-84
This work aimed to evaluate the phytochemical content and to determine the antioxidant and cytotoxic activities of methanol
extracts of the carob tree (Ceratonia siliqua L.) germ flour. The extracts were rich in phenolic compounds, had considerable antioxidant activity, and reduced the viability
of cervical (HeLa) cancer cells. The chemical content and the biological activities of the extracts were significantly affected
by gender and cultivar. Female cultivar Galhosa had the highest levels of phenolic compounds, and the highest antioxidant
activity. Extracts from the hermaphrodite trees and from the female cultivars Galhosa and Costela/Canela exhibited the highest
cytotoxic activity. The most abundant compound was theophylline. The phenolic content was correlated to both antioxidant and
cytotoxic activities. Our findings provide new knowledge about the health implications of consuming food supplemented with
carob germ flour. 相似文献
185.
Sara Sánchez-Moreno Sean Smukler Howard Ferris Anthony T. O’Geen Louise E. Jackson 《Biology and Fertility of Soils》2008,44(5):727-744
The aim of this paper was to assess biodiversity among different habitats of an organic farm and the relationships between
some soil properties, nematode taxonomic diversity, and soil food web condition. Eight habitats were studied in the farm:
ponds, ditches, a riparian corridor, hedgerows, and four agricultural fields (mustard, oats, fallow, and legumes). The undisturbed
riparian corridor had higher soil and concentrations, and potentially mineralizable N and higher abundances of bacterivore nematodes and longer food webs. Canonical
correlation analysis showed associations between habitats and nematode trophic groups: predatory and bacterial-feeding nematodes
in the riparian corridor and hedgerows, omnivore nematodes in the ponds and ditches, and fungal-feeding nematodes in the legume
field. Soil chemical and physical properties mirrored the aboveground farm patterns and were more similar among habitats that
were or had been cultivated, compared to the riparian corridor. Soil food web indices, based on functional analysis of nematode
faunal composition, reflected the aboveground landscape heterogeneity. Discriminant analysis indicated that soil food web
indices separated the two most disturbed habitats (ponds and tailwater ditches) from the two least disturbed habitats (the
riparian corridor and hedgerows). The indices correlated with soil functioning as inferred by soil properties. Abundance of
nematode taxa was not associated with aboveground landscape patterns. The complexity of the soil food web may have been influenced
by (1) environmental factors that differed between years, (2) different time periods since disturbance in the various habitats,
and (3) movement of nutrients and organisms by water flow between habitats in the farmscale. 相似文献
186.
Background and Objectives
Soil nitrate nitrogen (NO3 −-N) accumulation is related closely to NO3 − leaching, which is an important issue in groundwater pollution, especially in intensive agricultural areas with saline soils where volumes of water are used in irrigation to avoid salt accumulation in the root zone. However, in the saline environment in Hai River Basin, China, the importance of detailed research into NO3 −-N distribution in the root zone has not been adequately recognized. Considering the impacts of eco-environmental system N and crop production, the present study aimed at contributing to an understanding of the effects of N application rate on soil NO3 −-N distribution, NO3 −-N residue, N loss, and maize (Zea mays L.) yield in this region. 相似文献187.
Caterina Palombo Patrick Fonti Bruno Lasserre Paolo Cherubini Marco Marchetti Roberto Tognetti 《Annals of Forest Science》2018,75(4):93
Key message
Comparisons between compression and opposite wood formation in prostrating Pinus mugo indicate that the secondary meristem can produce more tracheids with thicker walls by also increasing the number of contemporaneously differentiating cells, rather than only increasing the duration or the rate of cell formation.Context
Although cambium tissues within a stem experience the same climatic conditions, the resulting wood structure and properties can strongly differ. Assessing how meristem differently regulates wood formation to achieve different anatomical properties can help understanding the mechanisms of response and their plasticity.Aims
We monitored the formation of compression (CW) and opposite (OW) wood within the same stems to understand whether achieved differences in wood structure are caused by modifications in the process of cell formation.Methods
We collected weekly microcores of compression and opposite wood from the curved stem of ten treeline prostrating mountain pines (Pinus mugo Turra ssp. mugo) at the Majella massif in Central Italy.Results
Results indicate that cambium formed approximately 1.5 times more cells in CW than OW, despite that CW cell differentiation only extended 2 weeks longer and the residence time of CW cells in the wall-thickening phase was only 20% longer. Differences in their formation were thus mainly related to both the rates and the width of the enlarging and wall-thickening zones (i.e., the number of cells simultaneously under differentiation) and less to duration of cell formation.Conclusion
We conclude that to achieve such a different wood structures, the efficiency of the secondary meristem, in addition of altered rate of cell division and differentiation, can also modify the width of the developing zones. Thus, deciphering what rules this width is important to link environmental conditions with productivity.188.
The Flowering Locus T (FT)-like genes of angiosperms are highly conserved. The FT-encoded proteins include a phosphatidylethanolamine-binding domain that is involved in the control of the shoot apical meristem identity and flowering time. In the present study, FT genes were investigated in 20 bamboo species that are grouped into sympodial, mixed and scattered bamboos based on their morphology. All examined orthologous FT genes consisted of four exons and three introns. Their encoded protein sequences contained the critical amino acid residues Tyr85, Glu109, Leu128, Tyr134, Trp138, Arg139, Gln140 and Asn152, of which each possesses a biological function. The DNA sequences were rich in single nucleotide polymorphism (SNP) sites. The SNP frequency was 1 SNP/16.8 bp, and the nucleotide diversity (π) equaled 0.265. Some SNPs altered restriction enzyme sites or resulted in changes in amino acid contents. The correlation analysis showed that several SNPs were informative in relation to the underground rhizome types of bamboos. Therefore, FT polymorphisms could be used as a tool to identify the underground rhizome types of bamboos. The phylogenetic tree constructed based on the FT gene sequences showed that the obtained clustering was consistent with the underground rhizome types. The SNP markers developed in the present study will provide information on the genetic diversity of bamboos and they can aid taxonomic study as well. 相似文献
189.
Promoter anchored amplified polymorphism based on random amplified polymorphic DNA (PAAP-RAPD) in cotton 总被引:1,自引:0,他引:1
Non-coding sequences account for a majority of the higher plant genome, some of which have important effects in gene regulation
and plant development. In an effort to develop molecular marker systems to search for polymorphisms associated with high fiber
yield and quality in cotton, we have developed a methodology that could specifically target the regulatory regions of the
cotton genome. In this study we designed 10-nucleotide degenerate promoter primers based on conserved core promoter sequences
and tested their applicability in PCR amplifications in combination with 10-mer random amplified polymorphic DNA (RAPD) primers.
The amplified markers are called promoter anchored amplified polymorphism based on RAPD (PAAP-RAPD). Forty cotton genotypes
with diverse genetic and geographical backgrounds were used to test the PAAP-RAPD system using polyacrylamide gel electrophoresis.
Based on PAAP-RAPD markers amplified from 12 primer combinations, the 40 genotypes were classified into five distinctive groups:
two Upland cotton (Gossypium hirsutum) groups from China, another two Upland cotton groups from the USA, and one group from American Pima cotton (G. barbadense). The groupings are in general consistent with their genetic and geographical origins. Thirty-six PAAP-RAPD and RAPD fragments
were cloned and four of them were further subjected to sequence analysis. Signal scanning using software PLACE confirmed that
they contained an array of cis-regulatory sequences in addition to the core promoter sequences. The results demonstrate the
potential application of PAAP-RAPD as a new marker system specifically targeting regulatory regions of the plant genome. 相似文献
190.
Hayley R. Tumas Brian M. Shamblin Mark Woodrey Nathan P. Nibbelink Richard Chandler Campbell Nairn 《Landscape Ecology》2018,33(9):1585-1601