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EAMUS D.; THOMPSON W.; CAIRNEY J. W. G.; JENNINGS D. H. 《Journal of experimental botany》1985,36(7):1110-1116
Eamus, D., Thompson, W., Cairney, J. W. G. and Jennings, D.H. 1985. Internal structure and hydraulic conductivity of basidiomycetetranslocating organs.J. exp. Bot. 36: 11101116. The presence in rhizomorphs of Armillaria mellea and cords ofPhallus impudicus of wide diameter hyphae (520 {diaeresis}m),which run for considerable distances along these linear organs,has been demonstrated. The longitudinal hydraulic conductivityof these organs has been determined experimentally and similarvalues were obtained when the hydraulic conductivity was calculatedtheoretically on the basis that the vessel hyphae were the solechannel for water movement along these organs. The experimentaldata have been discussed in relation to other data for long-distancetranslocation in basidiomycete linear organs. It is concludedthat the vessel hyphae are the main channels for turgor-driventranslocation. Key words: -Basidiomycete fungi, translocation, hydraulic conductivity 相似文献
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Abstract Variability in spatial and temporal patterning of flowering by populations of rainforest trees fed upon by honeyeaters and flower-visiting parrots was studied for 2 years in lowland tropical hill forest in Papua New Guinea. All 2200 trees in a 3 ha plot were tagged, identified, mapped and monitored monthly. Of 274 tree species present, 86 flowered during the course of the study; during any given month, approximately 20% of the species flowering that month were visited by nectarivorous birds. Results showed that overall flower resources (total number of species, and number of bird-pollinated species, individuals and flowers) fluctuated during the year, decreased during the dry season and increased during the wet season. In addition, there was a wide range of temporal variation within and among tree species in length and timing of flowering period, percentage of each conspecific population flowering from year to year, and degree of synchrony among flowering conspecifics. Spatial dispersion of tree populations also varied, from clumps to scattered single individuals. Resident bird species were correlated with synchronously flowering trees, whereas nomadic bird species were correlated with asynchronously flowering trees. Resident birds were also associated with smaller blooming displays per tree, whereas nomadic birds were associated with trees that bloomed massively. There was no correlation between avian nomadism and spatial dispersion of tree populations. Thus nomadic birds seem to range in search of rich but unpredictable resources; resident birds may rely more on predictable, but smaller resources. 相似文献
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S. B. THOMAS L. F. L. CLEGG E. J. NOKES D. G. GRIFFITHS J. L. TAIT ELEANOR JONES-EVANS 《Journal of applied microbiology》1951,14(2):191-199
SUMMARY: A field-scale experiment carried out in Wales and the West Midlands, in which the temperature-compensated clot-on-boiling (C.O.B.) test of Rowlands & Hosking (1951) was applied to 11,626 samples of designated milk, morning, mixed and evening milk, gave proportions of failures in the ratio 1:2:3 respectively. Despite temperature compensation, failures varied according to atmospheric temperature from c. 50% at 72°F. or more to 10% at 56°F. or less and averaged 20% during the summer and 7% during the six winter months.
No marked differences were noted between the keeping qualities of tuberculin tested or accredited milk. During the winter no difference was found between producer-wholesaler and producer-retailer supplies, but the latter had a higher proportion of failures of evening and mixed milks during the summer.
In a set of 8,297 samples examined in addition by the methylene blue and coli-aerogenes tests, the C.O.B. test gave a lower incidence of failures than either the methylene blue or combined methylene blue and coli-aerogenes tests throughout almost the entire year. It is suggested that a temperature-compensated C.O.B. test is practicable as a routine procedure. 相似文献
No marked differences were noted between the keeping qualities of tuberculin tested or accredited milk. During the winter no difference was found between producer-wholesaler and producer-retailer supplies, but the latter had a higher proportion of failures of evening and mixed milks during the summer.
In a set of 8,297 samples examined in addition by the methylene blue and coli-aerogenes tests, the C.O.B. test gave a lower incidence of failures than either the methylene blue or combined methylene blue and coli-aerogenes tests throughout almost the entire year. It is suggested that a temperature-compensated C.O.B. test is practicable as a routine procedure. 相似文献
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THOMPSON WENDY; BROWNLEE C.; JENNINGS D. H.; MORTIMER A. M. 《Journal of experimental botany》1987,38(5):889-899
Thompson, W., Brownlee, C, Jennings, D. H. and Mortimer, A.M. 1987. Localized, cold-induce inhibition of translocationin mycelia and strands of Serpula lacrimans. J. exp.Bot. 38: 889899 The effect has been investigated of localized low temperatureon translocation of 32P across myceliui of Serpula lacrimansusing two gas-flow detectors capable of recording radioactivitycontinuously. When the temperature of a band of mycelium wasreduced to 0 ? C, radioactivity ceased to accumulai and in factdeclined under the detector (number 2) separated from the sourceof radioactivity by tr cold-treated mycelium. In the myceliumbeneath the other detector (number 1), closest to the sourceradioactivity, the rate of accumulation of radioactivity increased.When the temperature was raised t 20 ?C, radioactivity beganto accumulate in the mycelium under detector 2 and, apart froma sma fluctuation, continued to accumulate at a uniform rate.In the mycelium under detector 1, the accumulation of radioactivitystopped for a short time but then recommenced at a rate similarto thi found at 0 ?C. In other experiments the distributionof radioactivity (14C) throughout the myceliui was measuredat the end in homogenized samples. In these experiments a bandof mycelium we subjected to 0 ?C or to 20 ?C for the whole experimentalperiod, or only after the mycelium had bee translocating radioactivityalready for 16 h. These experiments showed that the changesin the rate of accumulation of 32P in living mycelium underthe two gas flow detectors used for in situ measurements werenot due to a reversal of the flow of translocation. The resultsare consistent with an hypothesis that a turgor-driven massflow of solution is the mechanism for translocation in thisfungus and are considered in relation to the results of similarexperiments on phloem translocation in higher plants. Key words: Serpula lacrimans, mycelium, translocation, low-temperature, phloem transport 相似文献
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Studies on Factors which promote Germination of Raspberry Seeds 总被引:1,自引:0,他引:1
The germination of raspberry seeds was favoured by applyingcertain combinations of chemical pretreatment before givingup to six weeks of moist-chilling before sowing, by adding 500p.p.m. gibberellic acid just before sowing, and by providingsupplementary light after sowmg. The most useful chemical pretreatmentwas 20 minutes with concentrated sulphuric acid followed bysix days with 1.0 per cent calcium hypochlorite containing anexcess of calcium hydroxide. For some seed samples such pretreatmenteliminated the need for a subsequent period of moist-chilling,but for others a six-week period of moist-chilling was stillrequired. Pretreatment with higher concentrations than 1.0 percent of calcium hypochiorite, 0.5 per cent of sodium hypochlorite,or 1.0 per cent of thiourea, or pretreatment with the statedconcentrations of these chemicals but in each case without theaddition of calcium hydroxide, frequently delayed or preventedgermination. The results of these studies are in accord withthe hypothesis that the germination capacity of raspberry seedsis determined by interactions between growth inhibitors andpromoters. Such substances have been detected m blackberry seedsand it is suggested that a similar situation exists in seedsof the raspberry. 相似文献