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91.
达斡尔族成人的体格,体型及半个多世纪来的变化   总被引:10,自引:3,他引:7  
朱钦  张威 《人类学学报》1996,15(2):119-126
对内蒙古自治区莫力达瓦族353名(男187,女166)20-60岁达斡尔族进行了活体观察与测量,总结了达斡尔族的体格特征和类型。并在城乡之间和与半个世纪以前同一地区达斡尔族的体质资料之间进行了比较。  相似文献   
92.
羊角椒辣味物质成份分析   总被引:2,自引:0,他引:2  
用紫外光谱法、红外光谱法和高效液相色谱法分析羊角椒中辣味物质纯度与组成,表明辣味物质由辣椒素、二氢辣椒素和降二氢辣椒素组成。  相似文献   
93.
蛇胆祛痰作用的实验研究   总被引:2,自引:0,他引:2  
李琮辉  王丕荣 《蛇志》1996,8(4):8-9
用2组小鼠,每组10只。实验组用蛇胆酒灌胃,对照组用生理盐水灌胃,均以气管内酚红排泄法观察。结果示,酚红排泄量实验组比对照组明显为高。说明蛇胆确有增加小鼠气管分泌,稀释痰液的作用  相似文献   
94.
鹅掌楸雌配子体败育对生殖的影响   总被引:12,自引:0,他引:12  
胚珠和雌配子体败育是限制鹅掌楸生殖成功的一个重要因素。中国东部和西部鹅掌楸种群在雌配子体发育的各阶段上的败育程度有差异,以西部种群的发育较好。西部分布区较合适的生境促进了胚囊的发育,一定温度和湿度的环境可以活化珠心细胞输送营养物质供给雌配子体发育,提高受精和结籽的能力  相似文献   
95.
根据14丘稻田稻茎毛眼水蝇幼虫调查资料.对其幼虫分布型进行了分析。结果表明;用I、CAm/m、Iσ四种聚集指标法测定,64.3%的田块呈随机分布.28.4%为均匀分布.7.3%为聚集分布。用Iwao平均拥挤度和Taylor幂法则测定.其田间分布型符合随机分布。用频次拟合法测验,50%的田块同时符合渡松、奈曼和负二项分布三种分布型;35.7%的田块同时符合2种分布型。根据该虫田间分布型的特点.制定了相应的序贯抽样技术。  相似文献   
96.
Barley (Hordeum vulgare L.) was grown with UV-B (280–320 nm) at levels simulating 25 nr 5% ozone depletion on the date of the summer solstice al 40°N latitude, with UV-A (320–400 nm), or with no supplemental irradiation. In plant growth chambers providing 300 μmol m?2 s?1 photosynthetically active radiation (PAR). UV-B-grown leaves elongated more slowly than controls but reached the same final length 1 day later. Leal specific fresh weight (mass leaf area?1) was significantly increased by UV-B after the 7th day of growth. IV-B did not significantly affect leaf area, fresh weight, dry weight, total chlorophylls, total carotenoids or photosynthetic quantum efficiency. CO2 assimilation was decreased by UV-B only at internal CO2 levels above 250 μl l?1. By the 8th day of growth, UV-B increased flavonoid (saponarin and lutonarin) accumulation in both the lower epidermis and the mesophyll: about 40% of the saponarin and 20% of the lutonarin were in the lower epidermis under all experimental conditions. Glasshouse conditions proved too variable for reproducible determination of growth and photosynthesis but were reliable for determining developmental changes in flavonoid (saponarin and lutonarin) accumulation and provided up to 800 μmol m?2 s?1 PAR. In the glasshouse UV-B-grown leaves had more flavonoids than controls al all stages from 5 to 30 days after planting: ca 509 more saponarin and 100% more lutonarin. Levels of soluble (vacuolar) ferulic acid esters were similar under all conditions on day 5. and on day 20 or later, but were significantly higher in UV-B-grown plants on days 10 and 15. UV-B decreased insoluble (cell-wall-bound) ferulic acid esters on a whole leaf basis but significantly increased this fraction in the lower epidermis. UV-A had no significant effects on growth, photosynthesis or ferulic acid, but it slightly increased flavonoid accumulation. The results are discussed in terms of secondary phenolics as a tissue-specific, developmentally regulated adaptive response to UV-B.  相似文献   
97.
云南普通马矮型马蛋白多态性及其品种分化关系   总被引:3,自引:1,他引:2  
宿兵  解德文 《动物学研究》1995,16(2):126-131
本文运用蛋白电泳技术对来自云南省文山州马关县和麻栗坡县的21匹普通马和14匹矮型马进行了分析。共分析遗传座位44个,其中有10个座位检测到多态性。根据分子钟假说和相应的公式,推算两者的分歧时间约为18.5万年。  相似文献   
98.
An ecological survey was carried out to determine the levels of nutrients and heavy metals in the sediments and leaf tissues of two dominant mangrove plant species, Kandelia candel and Aegiceras corniculatum, in Futian mangrove forest, Shenzhen, the People's Republic of China. The spatial and seasonal variations of these elements were also investigated. The results show that there was no major difference between two sampling sites 150 m apart. In both sites, the sediment concentrations of total and NH4 +-N, total and extractable P, total and extractable K, total organic carbon were consistently higher in the landward locations and decreased gradually towards the sea. The sediment sample collected at the seaward edge of the mangrove plant community had the lowest levels of nutrient and organic matter. The vertical variations (from the land to the sea) of sediment heavy metals were less obvious and no particular trend could be identified. Extremely high contents of Cu, Cd, Pb, Cr and Zn were found at certain locations, suggesting the occurrence of some local contamination. The mean total metal concentrations in sediments decreased in the order Mn > Zn > Cu > Cr = Pb > Cd for the sample locations. Most of the heavy metals were not in a bioavailable form as the concentrations of extractable metals were relatively low (< 1% of total metals). Pb, Cr and Cd were not detected in leaf samples. Leaf C, N, P and K contents were similar between the two species and no significant difference was found among locations, although A. corniculatum seemed to have lower Mn concentrations than K. candel. With reference to temporal variations, no significant difference in sediment concentrations of some nutrients and metals was found between the spring and autumn seasons.  相似文献   
99.
H Qin  Z Liu    S F Sui 《Biophysical journal》1995,68(6):2493-2496
Two-dimensional crystals of avidin were obtained on mixed lipid monolayers containing biotinylated lipids (N-biotinyl-dipalmitoyl-L-alpha-phosphatidyl ethanolamine and dioleoyl phosphatidyl choline) by specific interaction. Image analysis of electron micrographs of these crystals revealed p2 symmetry with the unit cell parameters a = 66 +/- 2 A, b = 68 +/- 1 A, and gamma = 121 +/- 4 degrees. The projection map showed, at a resolution of about 27 A, that the four subunits within one avidin molecule are separated into two parts. Comparison between avidin and streptavidin reveals that avidin molecule binds to the lipid monolayer in an orientation similar to that of streptavidin.  相似文献   
100.
Alkaline borohydride treatment is widely used for the release of carbohydrate moieties from O-glycosylated glycoproteins and mucins. We have adapted this procedure to micro quantities of glycoproteins blotted on membranes. After electrophoresis and transfer to nitrocellulose, nylon or polyvinylidene difluoride membrane, alkaline borohydride treatment was done directly on glycoprotein containing areas of membrane which were cut out with the aid of guide strips stained with Coomassie Blue or lectin-digoxigenin. In combination with standard saccharide fractionation techniques, this procedure can be used to characterize the oligosaccharides of mucins or mucin-type glycoproteins that are separated by gel electrophoresis from crude sources. Using this approach we have characterized the saccharides derived from the two species of epitectin, a malignancy-associated mucin type glycoprotein, isolated from metabolically labelled H.Ep2 cells.  相似文献   
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