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支气管斜位体层摄影两种方法的初步比较
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作者 刘继生 吴恩惠 +1 位作者 赵常江 刘荫棣 《临床放射学杂志》 1985年第3期136-137,T023,共3页
支气管斜位体层摄影是目前评价肺门结构的主要放射学方法之一,在支气管肺癌的X线诊断中占有很重要的地位,支气管斜位体层摄影有两种方法。国外报道均用单斜法(1,2),即仅有背部后斜一个倾斜;国内报道多用双斜法,即除背部后斜外... 支气管斜位体层摄影是目前评价肺门结构的主要放射学方法之一,在支气管肺癌的X线诊断中占有很重要的地位,支气管斜位体层摄影有两种方法。国外报道均用单斜法(1,2),即仅有背部后斜一个倾斜;国内报道多用双斜法,即除背部后斜外,还使身体纵轴向头侧倾斜15-20度。有学者认为两法有显著的区别(3),也有学者将两法合而论之(4),迄今尚未见对两法进行比较分析的文献。 展开更多
关键词 支气管斜位体层摄影 X线诊断 斜法 双斜法 比较
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A strength reduction method based on double reduction parameters and its application 被引量:40
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作者 袁维 白冰 +1 位作者 李小春 汪海滨 《Journal of Central South University》 SCIE EI CAS 2013年第9期2555-2562,共8页
In the traditional strength reduction method,the cohesion and the friction angle adopt the same reduction parameter,resulting in equivalent proportional reduction.This method does not consider the different effects of... In the traditional strength reduction method,the cohesion and the friction angle adopt the same reduction parameter,resulting in equivalent proportional reduction.This method does not consider the different effects of the cohesion and friction angle on the stability of the same slope and is defective to some extent.Regarding this defect,a strength reduction method based on double reduction parameters,which adopts different reduction parameters,is proposed.The core of the double-parameter reduction method is the matching reduction principle of the slope with different angles.This principle is represented by the ratio of the reduction parameter of the cohesion to that of the friction angle,described as η.With the increase in the slopeangle,ηincreases; in particular,when the slope angle is 45°,tηis 1.0.Through the matching reduction principle,different safety margin factors can be calculated for the cohesion and friction angle.In combination with these two safety margin factors,a formula for calculating the overall safety factor of the slope is proposed,reflecting the different contributions of the cohesion and friction angle to the slope stability.Finally,it is shown that the strength reduction method based on double reduction parameters acquires a larger safety factor than the classic limit equilibrium method,but the calculation results are very close to those obtained by the limit equilibrium method. 展开更多
关键词 double reduction parameter strength reduction method matching reduction principle slope stability
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