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排序方式: 共有324条查询结果,搜索用时 15 毫秒
1.
Kareem Fakhriya Rihan Hail Fuller Michael P. 《Journal of Crop Science and Biotechnology》2019,22(1):37-45
Journal of Crop Science and Biotechnology - Drought is a major limiting factor of wheat production globally. In this research, salicylic acid was used in order to increase drought tolerance in... 相似文献
2.
Matthew L. Peterson Dana J. Lee John Montgomery Michael Hellmair Andrea Fuller Doug Demko 《Fisheries Management and Ecology》2020,27(4):399-416
The spatial and temporal distribution of spawning activity by autumn‐run Chinook salmon Oncorhynchus tshawytscha (Walbaum) was examined across multiple years. The study period included two years of extreme drought conditions when water temperatures in the spawning reach of the Stanislaus River were considered sub‐optimal for spawning and egg incubation. Despite varying levels of superimposition, redd counts and densities remained stable and positively associated with river location, indicating that superimposition may be driven by habitat preference rather than the absence of suitable spawning locations. Spawning occurred slightly later during drought years (6–10 days later compared with wetter years). This delay was attributable to deferred migration instead of deferred spawning, and the majority of redds were constructed at water temperatures exceeding the optimal temperature range. As a consequence, estimates of juvenile production during 2014 and 2015 were among the lowest on record. These findings may be related in part to the high hatchery contribution to the population, above‐average temperatures during spawning and incubation, and superimposition rates. Management recommendations include adequate cold‐water storage in the upstream reservoir, refined spawning habitat restoration techniques in the light of superimposition rates and, on a broader system scale, actions that reduce the amount of stray hatchery Chinook salmon. 相似文献
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Summary The Andigena potatoes (Solanum tuberosum ssp.andigena) of the Commonwealth Potato Collection (C.P.C.) were screened for resistance to non-pathotype A populations ofHeterodera rostochiensis. Three populations were used: Duddingston (pathotype B), Nocton (pathotype C) and Changed Little Ouse (pathotype C). Resistance was found in C.P.C. 2775, 2802 and 2805. C.P.C. 2775 also had resistance to pathotype A (Feltwell population) and appeared to have two dominant genes,H
1 giving resistance to pathotype A andH
3 giving resistance to pathotypes B and C. C.P.C. 2802 was susceptible to pathotype A and appeared to have only anH
3-type gene. C.P.C. 2805, which has not been investigated thoroughly because the plants lacked vigour, may also have anH
1 and anH
3 gene. The value of C.P.C. 2775, 2802 and 2805 for breeding nematode-resistant potatoes will only be known when they have been tested with further non-pathotype A populations and when the genetics of resistance have been investigated thoroughly. 相似文献
5.
Summary A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0.3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants. Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls. Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline. During early shoot culture passages, proline levels were 3.6–4.7 times higher than controls, but this was reduced to 1.6 times after 10–12 culture passages in the absence of hydroxyproline. Possible reasons for this decline are discussed. Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors. These will then be evaluated for any alteration in frost tolerance.Abbreviations IBA
Indole-3-butyric-acid
- NEU
N-nitroso-N-ethylurea 相似文献
6.
Rungapamestry V Duncan AJ Fuller Z Ratcliffe B 《Journal of agricultural and food chemistry》2006,54(20):7628-7634
In cabbage, glucosinolates such as sinigrin are hydrolyzed by plant myrosinase to allyl isothiocyanate (AITC), allyl cyanide, and, in the presence of an epithiospecifier protein, 1-cyano-2,3-epithiopropane (CEP). Isothiocyanates have been implicated in the cancer-protective effects of Brassica vegetables. The effect of processing on the hydrolysis of glucosinolates was investigated in cabbage. Cabbage was steamed or microwaved for six time durations over 7 min. Glucosinolate concentrations were slightly reduced after microwave cooking (P < 0.001) but were not influenced after steaming (P < 0.05). Myrosinase activity was effectively lost after 2 min of microwave cooking and after 7 min of steaming. Hydrolysis of residual glucosinolates following cooking yielded predominantly CEP at short cooking durations and AITC at longer durations until myrosinase activity was lost. Lightly cooked cabbage produced the highest yield of AITC on hydrolysis in vitro, suggesting that cooking Brassica vegetables for a relatively short duration may be desirable from a health perspective. 相似文献
7.
Nahuel Fittipaldi Troy E. Fuller Janet F. Teel Thomas L. Wilson Thaddeus J. Wolfram David E. Lowery Marcelo Gottschalk 《Veterinary microbiology》2009,139(3-4):310-317
Streptococcus suis is an important swine pathogen and a zoonotic agent. Differences in virulence have been noted among the 33 described serotypes, serotype 2 being considered the most virulent. In this study, we aimed at assessing the serotype distribution and the production of virulence-associated markers by strains recovered from diseased pigs in the United States (U.S.). Results showed that among the 100 strains evaluated, serotype 3 (20% of the isolates) and serotype 2 (17%) were the most prevalent. We then investigated the presence in these isolates of the genes sly, epf and mrp, encoding the virulence-associated markers suilysin (SLY), extracellular factor (EF) and muramidase-released (MRP) protein, respectively. The effective production of the markers by the strains was also verified. Results showed that the presence of the gene did not always correlate with actual expression of the respective protein. In the case of MRP, this was due, in most cases, to frameshift mutations at the 5′ end of the gene resulting in premature stop codons. The most prevalent phenotypes among U.S. strains were MRP+EF−SLY− (40%) and MRP−EF−SLY+ (35%). Serotype distribution greatly differed from that reported in several European countries, as did the production of virulence markers, particularly for serotype 2. On the other hand, our results for the U.S. S. suis isolates are similar to those reported for Canadian strains, suggesting a common status in North America. 相似文献
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Sorghum (S. bicolor L. Moench cv. Bok 8) plants were grown in soil or sand-perlite low in plant-available N and P. Plants were inoculated with a vesicular-arbuscular mycorrhizal (VAM) fungus, or a strain of Azospirillum brasilense or both endophytes together. Plants received a nutrient solution which did not contain N or P. Increases in plant dry weight, shoot-to-root ratios, and the N content of dually-infected plants could be accounted for by summing the VAM and Azospirillum effects. For sorghum inoculated with both endophytes, the presence of A. brasilense in the rhizosphere increased VAM colonization and biomass, while the N input due to Azospirillum decreased, possibly due to competition for carbohydrates.Comparisons between sorghum grown with or without VAM-fungal infection in four growth media showed that edaphic factors other than P availability determined the host response to VAM infection. The P-fixing capacity of the soil, rather than the amount of available (NaHCO3-extractable) P, influenced the balance between mutualistic and parasitic VAM-fungal growth. 相似文献
10.