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11.
有机磷农药降解菌的紫外诱变育种 总被引:20,自引:0,他引:20
有机磷农药降解菌地衣芽孢杆菌( Bacilluslicheniformis) 经紫外线诱变后,筛选出突变菌株P12 .在θ=30℃,溶解氧ρ(O2) =2 .5 mg L-1 的培养条件下,3 d 内对甲胺磷的降解率为80 .1% ,比出发菌株提高了将近10%的降解率.农药斜面连续传代10 次,降解活力保持稳定. 相似文献
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我国正在建设的青藏铁路是世界上海拔最高、线路最长的高原铁路.其气候特点对橡胶制品提出了新的技术要求,为适应在该气候条件下的运用需要,进行了针对空气弹簧胶囊用橡胶的耐紫外线老化试验研究工作,试验表明随着紫外线老化时间的增加,其硬度和300%定伸强度均提高,但拉伸强度和扯断伸长率随着紫外线老化时间的增加而降低;通过与胶料的耐臭氧试验和大气老化试验比较,基本可以认为引起空气弹簧胶囊表面龟裂的主要原因是受力状况、臭氧和大气老化的作用,而紫外线对橡胶的表面龟裂影响作用不大,因此,为提高空气弹簧胶囊的耐老化性能,主要考虑降低橡胶的受力,提高耐臭氧和耐大气老化性能. 相似文献
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F. Mougeot J. Martínez-Padilla L. Pérez-Rodríguez G. R. Bortolotti 《Behavioral ecology and sociobiology》2007,61(5):741-751
Among the most familiar sexual signals are red, yellow, and orange sexual traits pigmented by carotenoids. Many birds can
detect near-ultraviolet (UV) light, and UV signals can play key roles in mate choice. Grouse (Tetraonidae) exhibit bright
carotenoid-dependent sexual ornaments, their supra-orbital combs, which to humans appear orange-red. Combs also reflect in
the UV, which is not visible to humans but is likely to be visible to grouse. In male red grouse Lagopus lagopus scoticus, we show that comb UV reflectance decreases with increasing comb size and redness. By removing the epidermis of combs, where
carotenoid pigments are, we show that the UV reflectance is a property of the dermis, underneath the red pigmented epidermis.
Carotenoid pigmentation of combs acted as a mask to reduce reflectance by the dermis in the range 400–550 nm and in the UV,
300–400 nm. Patagium skin (non-ornamental skin under the wing) also reflects in the UV, but epidermis removal on this bare
part tended to reduce UV reflectance, whereas removal of the red epidermis of combs increased UV reflectance. Males in better
condition (greater body mass relative to size) had bigger and redder combs, but with less UV. Thus, carotenoid pigments of
grouse combs are deposited on a white background with significant UV reflectance, which can influence how the signal is perceived
by conspecifics. Carotenoid-based traits exhibit UV reflectance in a number of species, but how UV reflectance and carotenoid
pigmentation influence colour remains little known for integumentary ornaments compared to plumage traits. UV vision is not
uncommon in birds and other animals, so future studies should investigate how UV reflectance influences the perception of
carotenoid-based signals of quality. 相似文献
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Kaspar Delhey Anne Peters Arild Johnsen Bart Kempenaers 《Behavioral ecology and sociobiology》2007,61(6):853-862
Sex-allocation theory predicts that females paired to attractive males should bias the brood sex ratio towards male offspring,
as these would inherit the attractiveness of their father. We studied sex allocation based on male ornamentation in blue tits.
Brood sex ratios varied with male UV coloration in an age-dependent manner. For juvenile males, the proportion of sons increased
with increasing UV ornamentation, which is in agreement with previous findings from a Swedish population. However, the relationship
between UV ornamentation and brood sex ratio was reversed for adult males, with females paired to less UV-ornamented adult
males producing more sons. This pattern fits with the observation that, in our population, less UV-ornamented adult males
sire the majority of extra-pair young. To test the causality of the association between brood sex ratio and male coloration,
we experimentally manipulated crown colour largely within the natural range. We created two groups of males: one with higher
and one with lower UV reflectance, UV(+) and UV(−), respectively. Contrary to our expectations, there was no significant treatment
effect. However, in UV(−), but not UV(+) males, the proportion of sons was negatively correlated with male coloration before
manipulation. This suggests that the UV(−) treatment caused males that were more UV ornamented to decline more in attractiveness,
as shown in a similar experiment in Sweden. However, given that correlational patterns differ between these populations, similarities
in experimental results should not be taken as evidence for consistent patterns of adaptive sex allocation in this species. 相似文献
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高灵敏XRF测定废水中痕量砷 总被引:2,自引:0,他引:2
本文提出了在硫酸介质中,以锌粒还原产生氢化物,溴化铜溶液吸收,微孔滤膜过滤制成薄样,X射线荧光测定水中痕量砷的分析方法。 相似文献