全文获取类型
收费全文 | 166篇 |
免费 | 14篇 |
出版年
2013年 | 2篇 |
2012年 | 4篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 3篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1967年 | 1篇 |
1966年 | 6篇 |
1965年 | 1篇 |
1964年 | 2篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 2篇 |
1959年 | 11篇 |
1958年 | 7篇 |
1957年 | 12篇 |
1956年 | 8篇 |
1955年 | 6篇 |
1954年 | 5篇 |
1953年 | 9篇 |
1952年 | 2篇 |
1951年 | 8篇 |
1950年 | 6篇 |
1949年 | 4篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1934年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有180条查询结果,搜索用时 15 毫秒
41.
Fusarium caeruleum produced an arabanase which showed maximalactivity at pH 3·5 and which liberated arabinose andits oligomers from -l,3-arabinofuranan and isolated potato tuberparenchyma cell walls. This enzyme was most active in dry rotlesions produced in susceptible potato tubers by a fast-growingisolate of F. caeruleum. This arabanase is not of primary importancein causing tissue maceration, protoplast death or electrolyteloss but it may play a secondary role in these processes. 相似文献
42.
Glyphosate promoted the activity of phenylalanine ammonia lyase(PAL) in both single node rhizome buds of Agropyron repens androot tips of wheat seedlings, in the latter case correlatinginversely with decline in respiratory activity. Differentialrates of 14C-amino acid incorporation suggest that glyphosatedepleted the phenylalanine protein precursor pool with resultantinhibition of protein synthesis, as evidenced by a rapid declinein the level of soluble protein. Promotion ofPAL is assumed to occur by derepression through decline in end-productlevels. Activities of shikimate: NADP oxidoreductase (SORase),chorismate mutase, and polyphenol oxidase (PPO) were also elevated,but to lesser extents than for PAL. 相似文献
43.
ROSEMARY A. COLE KATHLEEN PHELPS P. R. ELLIS J. A. HARDMAN 《The Annals of applied biology》1987,110(1):135-143
Two carrot cultivars which represented contrasting levels of resistance to carrot fly, Psila rosae, were grown in a replicated field experiment at Wellesbourne in 1984–85. Seed was sown on five occasions between April and August 1984 and the crop harvested after a minimum growth in the field of 16 wk on seven occasions between August 1984 and February 1985. A highly significant correlation (r = -0.78; P > 0.001) between the levels of carrot fly damage and the concentration of chlorogenic acid in the roots enabled a model to be formulated to predict the relative predisposition to carrot fly larval damage; high levels of chlorogenic acid early in the season predisposed roots to severe attack when they were older. 相似文献
44.
45.
Phenolic acids associated with the resistance of lettuce cultivars to the lettuce root aphid 总被引:3,自引:0,他引:3
ROSEMARY A. COLE 《The Annals of applied biology》1984,105(1):129-145
Phenolic acids, particularly caffeoylquinic acids, in lettuce root extracts were analysed by high pressure liquid chromatography (hplc), gas liquid chromatography (glc) and ultra-violet (uv) absorbance to seek a relationship with the resistance of certain lettuce cultivars to lettuce root aphid, Pemphigus bursarius. Although consistent results were obtained by each method, glc estimates of isochlorogenic acid tended to be low and uv estimates high. Hplc results were intermediate and since it was the easiest technique to perform routinely it was preferred. Isochlorogenic acid was the only caffeoylquinic acid detected in quantity and there were greater concentrations in resistant than in susceptible cultivars. Phenylalanine-ammonia lyase (PAL), the first enzyme in the phenyl propanoid pathway, is more active in resistant cultivars. Although these cultivars also had a greater tendency to browning when damaged, it was not due to greater polyphenol oxidase activity but probably to the presence of more isochlorogenic acid substrate. The results were consistent with an association between isochlorogenic acid concentration, PAL activity and resistance to P. bursarius. 相似文献
46.
47.
Infection of potato tubers by the soft-rotting fungi Phytophthoraerythroseptica and Pythium debaryanum resulted in multiplicationof endogenous tuber bacteria. This effect was not evident afterinfection by dryrotting fungi. Some of the bacteria isolatedproduced pectolytic and hemicellulolytic enzymes in vitro andwere themselves capable under certain conditions of degradingtuber tissue. 相似文献
48.
TERRY J. KREEGER KHURSHEED MAMA MATTHEW HUIZENGA COLE HANSEN CYNTHIA TATE 《The Journal of wildlife management》2010,74(4):902-905
Abstract: We immobilized elk with either isoflurane to produce general anesthesia (control), 0.01 mg/kg carfentanil plus 0.1 mg/kg xylazine, or 0.25 mg/kg butorphanol plus 0.4 mg/kg azaperone plus 0.15 mg/kg medetomidine (BAM) and measured the bispectral index (BIS). The carfentanil-xylazine BIS (70.4 + 1.4) and the BAM BIS (60.2 + 1.5) were higher than the control BIS (47.2 + 4.1; P ≤ 0.001). These data indicate that opioids produce neuroleptanalgesia and not general anesthesia or sedation, which explains observed elk responses to these drugs. 相似文献
49.
50.
Odor identification: perceptual and semantic dimensions 总被引:8,自引:8,他引:0