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91.
Avenanthramides (avn) are antioxidant compounds found in oat tissues, including the grain, that are of interest from a nutritional standpoint. In this study, we have measured avenanthramide concentration in the grain of 18 oat genotypes grown in six environments. These genotypes varied widely in crown rust (Puccinia coronata) resistance. Crown rust infected two of the six environments studied. The grain avenanthramide concentrations in the crown rust environments were significantly higher than those in the uninfected environments. Avenanthramide concentrations in the crown rust infected environments was also significantly correlated with their genetic crown rust resistance, as evaluated in the field. These results suggest that avenanthramide accumulation in the grain is associated with crown rust infection and that, in most of the cultivars evaluated, the extent of their accumulation also correlated with their genetic disease resistance; avenanthramide accumulation in the grain was, with noted exceptions, highest in those cultivars showing the greatest genetic resistant to crown rust. 相似文献
92.
BACKGROUND: The codling moth is one of the principal pests of apple in the world. Resistance monitoring is crucial to the effective management of resistance in codling moth. Three populations of codling moth in neonate larvae were evaluated for resistance to seven insecticides via diet bioassays, and compared with a susceptible population. In addition, apple plots were treated with labeled field rate doses of four insecticides. Treated fruit were exposed to neonate larvae of two populations from commercial orchards. RESULTS: Two populations of codling moth expressed two‐ and fivefold resistance to azinphos‐methyl, seven‐ and eightfold resistance to phosmet, six‐ and tenfold resistance to lambda‐cyhalothrin, 14‐ and 16‐fold resistance to methoxyfenozide and sixfold resistance to indoxacarb, but no resistance to acetamiprid and spinosad. The impact of the resistance to azinphos‐methyl, measured as fruit damage, increased as the insecticide residues aged in the field. In contrast, fruit damage in methoxyfenozide‐ and lambda‐cyhalothrin‐treated fruit was observed earlier for resistant codling moth. No differences in efficacy were found for acetamiprid. CONCLUSIONS: Broad‐spectrum insecticide resistance was detected for codling moth. Resistance to azinphos‐methyl, lambda‐cyhalothrin and methoxyfenozide was associated with reduced residual activity in the field. Broad‐spectrum resistance presents serious problems for management of the codling moth in Michigan. Copyright © 2008 Society of Chemical Industry 相似文献
93.
94.
Bogdan M. Strimbu John L. Innes Victor F. Strimbu 《European Journal of Forest Research》2010,129(5):961-974
The use of heuristic techniques in forest planning has been promoted by the need to solve complex problems that cannot be
solved using mixed integer programming. We proved that for merchantability standards ensuring the perfect bin-packing theorem
(PBPT), the maximum volume that can be harvested annually equals the sum of the maximum MAI of the stands. The method accommodates
optimality criteria at the stand level, regarded as maximum MAI, and at the forest level, regarded as maximum annual allowable
cut. We scheduled the harvesting by adjusting the first fit decreasing algorithm (FFD) to the PBPT conditions. When PBPT conditions
were not met, we developed a mixed integer programming solution to adjust the merchantability standards of the stands to the
distributional requirements of the PBPT, an adjustment that ensured the optimal performance of the FFD. The adjusted FFD was
compared with linear programming (LP) and simulated annealing (SA) using two harvesting ages (i.e., one based on MAI maximization
and one determined as the minimal age) and the same set of spatial temporal constraints for three areas in north-eastern British
Columbia, Canada. We found that the adjusted FFD performed 100 times faster than SA and for annual allowable cut (AAC) supplied
results that were more homogenous and at least 10% greater than the AAC supplied by SA. Furthermore, the adjusted FFD seemed
to be relatively insensitive to spatial constraints (i.e., adjacency), while SA displayed a 70% reduction in AAC in response
to an increase in adjacency delay from 1 year to 20 years. The results suggest that both adjusted FFD and SA are impacted
by the selection of the harvesting age, but the adjusted FFD could still outperform SA. 相似文献
95.
96.
Mota-Sanchez D Cregg B Hoffmann E Flore J Wise JC 《Journal of agricultural and food chemistry》2012,60(12):2958-2966
Infinite- and finite-dose laboratory experiments were used to study the penetrative and dislodgeable residue characteristics of (14)C-insecticides in apple fruit. The differences in dislodgeable and penetrated residues of three radiolabeled insecticides ((14)C-thiamethoxam, (14)C-thiacloprid, and (14)C-indoxacarb), applied in aqueous solution with commercial formulations, were determined after water and methanol wash extractions. The rate of sorption and extent of penetration into the fruit cuticles and hypanthium of two apple cultivars were measured after 1, 6, and 24 h of treatment exposure, using radioactivity quantification methods. For all three compounds, 97% or more of the treatment solutions were found on the fruit surface as some form of non-sorbed residues. For indoxacarb, sorption into the epicuticle was rapid but desorption into the fruit hypanthium was delayed, indicative of a lipophilic penetration pathway. For the neonicotinoids, initial cuticular penetration was slower but with no such delay in desorption into the hypanthium. 相似文献
97.
Extent of soil erosion and surface runoff associated with large-scale infrastructure development in Fujian Province, China 总被引:1,自引:0,他引:1
Guangyu WangJohn Innes Yang YushengChen Shanmu Judi KrzyzanowskiXie Jingsheng Lin Wenlian 《CATENA》2012,89(1):22-30
We examined runoff and sediment transport associated with large-scale construction projects in Fujian Province, China. Six experimental plots, comprised of four plot types, were designed to mimic typical conditions immediately following disturbance. It was found that natural vegetative cover reduces both runoff and erosion by approximately 36 and 7457 times over bare ground, and 16 and 1801 times over typically planted grasses, respectively. The increase in erosion associated with the replacement of native vegetation with bare ground or grasses due to large-scale infrastructure projects in Fujian from 1999 to 2004, amounted to an estimated loss of 1.76 × 107 tonnes of top soil and 3.04 × 108 m3 of surface runoff from the province during the bare soil construction phase, and an additional 4.25 × 106 tonnes of top soil and 1.35 × 108 m3 of surface runoff from the province associated with the first year of operation for each project. This has implications for frequency and occurrence of landslides and other geographic hazards, the transport of chemicals into waterways, the transport of goods through shipping passages, and the fertility of land in Fujian. 相似文献
98.
The achievement of sustainable forest management requires the incorporation of risk and uncertainty into long-term planning. Climatic change will have significant impacts on natural disturbances, species and ecosystems, particularly on landscapes influenced by forest management. Understanding where vulnerabilities lie is important in managing the risks associated directly or indirectly with climatic change. The vulnerability of landscapes to natural disturbances, the resilience of ecosystems and distribution of species are all important components that need to be considered when undertaking forest planning, but climatic change is rarely factored into such planning. In this study, the vulnerability of fire potential, fire regimes, ecosystems and species to climatic change was modelled for a 145,000 ha landscape in the south-central interior of British Columbia, Canada. The results from these analyses were used to guide forest zoning, using the triad zoning framework, and for the development of a “climate-smart” management framework. The use of climate-smart management is advocated as a decision-making framework for managing forested landscapes based on an understanding of landscape vulnerability to future climatic change. From this understanding, the maintenance of ecosystem health and vitality could be achieved. 相似文献
99.
Over three years, eight replicated experiments were conducted in which winter wheat was sown after a ley with and without seedbed applications of P and K. Fertilizer N was applied at 0, 45, 90 and 135 lb per acre in one dressing in early spring. Observations were made on tiller counts, grain size and yield.
There were no significant interactions between N and mineral fertilizer. Mineral fertilizer had no important effect on tillering or grain yield. Consideration of the previous fertilization of the pastures showed that there was probably an adequate reserve of P and K in the soil, although soil analysis did not always reveal it.
Nitrogenous fertilizer significantly increased fertile tiller numbers and raised yield of grain up to an application of 45 lb N per acre in 1960 and 90 lb N per acre in 1961 (after a wet winter). The average responses to 90 lb per acre of N after leys were 74, 6·3 and 101 cwt grain per acre in 1959, 1960 and 1961, respectively. In 1961 the corresponding response in an arable field was 16·3 cwt.
It is concluded that after a well-fertilized ley neither mineral fertilizers nor N are necessary in the seed bed and that the ley contributes about 45 lb N per acre towards the succeeding crop. The practical advantages of autumn drilling without fertilizer are stressed and reference is made to the importance of considering fertilizer applications for the rotation as a whole. 相似文献
There were no significant interactions between N and mineral fertilizer. Mineral fertilizer had no important effect on tillering or grain yield. Consideration of the previous fertilization of the pastures showed that there was probably an adequate reserve of P and K in the soil, although soil analysis did not always reveal it.
Nitrogenous fertilizer significantly increased fertile tiller numbers and raised yield of grain up to an application of 45 lb N per acre in 1960 and 90 lb N per acre in 1961 (after a wet winter). The average responses to 90 lb per acre of N after leys were 74, 6·3 and 101 cwt grain per acre in 1959, 1960 and 1961, respectively. In 1961 the corresponding response in an arable field was 16·3 cwt.
It is concluded that after a well-fertilized ley neither mineral fertilizers nor N are necessary in the seed bed and that the ley contributes about 45 lb N per acre towards the succeeding crop. The practical advantages of autumn drilling without fertilizer are stressed and reference is made to the importance of considering fertilizer applications for the rotation as a whole. 相似文献
100.
Comparative Susceptibility of Channel Catfish,Ictalurus punctatus; Blue Catfish,Ictalurus furcatus; and Channel (♀) × Blue (♂) Hybrid Catfish to Edwardsiella piscicida,Edwardsiella tarda,and Edwardsiella anguillarum 下载免费PDF全文
Cynthia Ware Lester H. Khoo Terrence E. Greenway David J. Wise Brian G. Bosworth Mark L. Lawrence Matt J. Griffin 《Journal of the World Aquaculture Society》2018,49(1):197-204
Members of the genus Edwardsiella are important pathogens of cultured and wild fish globally. Recent investigations into the phenotypic and genotypic variation of Edwardsiella tarda have led to the segregation of E. tarda into three distinct taxa: E. tarda, Edwardsiella piscicida, and Edwardsiella anguillarum. In catfish aquaculture in the southeastern USA, E. piscicida has been more commonly associated with disease than E. tarda or E. anguillarum, and recent research has demonstrated E. piscicida to be more pathogenic in channel catfish than E. tarda or E. anguillarum. Anecdotal reports from industry suggest an increased prevalence of E. piscicida associated with the culture of channel (♀) × blue (♂) hybrid catfish. This work investigated the comparative susceptibility of channel catfish, blue catfish, and their hybrid cross to molecularly confirmed isolates of E. tarda, E. piscicida, and E. anguillarum. There was significantly higher mortality in hybrid catfish compared to channel catfish following intracoelomic injection of E. piscicida. To our knowledge, E. piscicida is the first bacterial pathogen to demonstrate increased pathogenicity in hybrid catfish compared to channel catfish. 相似文献