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青海黑白花奶牛的血钾浓度常值 被引量:12
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作者 张才骏 马森 +2 位作者 许生成 杜志权 郑玉芳 《青海畜牧兽医杂志》 1992年第6期9-10,共2页
采用火焰光度计法测定了西宁市奶牛场饲养的青海黑白花奶牛96份血样的血钾浓度常值。它们的全血钾浓度为10.63±1.36mmol/L,红细胞钾浓度为20.34±3.17mmol/L,血浆钾浓度为4.58±0.40mmol/L。全血钾浓度与红细胞钾浓度之间... 采用火焰光度计法测定了西宁市奶牛场饲养的青海黑白花奶牛96份血样的血钾浓度常值。它们的全血钾浓度为10.63±1.36mmol/L,红细胞钾浓度为20.34±3.17mmol/L,血浆钾浓度为4.58±0.40mmol/L。全血钾浓度与红细胞钾浓度之间呈显著的正相关性联系(r=0.8602,P<0.0001)。 展开更多
关键词 黑白花奶牛 全血钾浓度 红细胞钾浓度 血浆钾浓度 相关性联系
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An Improved Direction Relation Detection Model for Spatial Objects
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作者 FENGYucai YIBaolin 《Geo-Spatial Information Science》 2004年第4期297-302,共6页
Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for mo... Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries. 展开更多
关键词 spatial databases geographic information systemst direction relations direction relation matrix
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