To assess the left ventricle regional systolic and diastolic function, left ventricle geometry and left venticle sphericity indexes in patients with dilated cardiomyopathy （DCM） by quantitative tissue velocity imagi...To assess the left ventricle regional systolic and diastolic function, left ventricle geometry and left venticle sphericity indexes in patients with dilated cardiomyopathy （DCM） by quantitative tissue velocity imaging （QTVI）. Methods Thirty normal subjects and 52 DCM patients underwent QTVI and colour Doppler flow imaging study in order to measure the left ventricular regional function along left ventricle apical long-axis view and the left ventricle geometry. Peak tissue velocities of left venticle regional muscular tissue during systole （ Vs）, systolic acceleration （ a）, early diastole（Ve） and left atrium contraction（Va） along left venticle apical long axis view were measured. The indexes of left ventricular regional systolic and diastolic function were mearsured at the same time. The left ventricle geometry shape was reflected from the systolic and diastolic sphericity index （Sis and Sid）, the left ventricular ejection fraction （LVEF） and D wave / A wave （PVd/PVa） of pulmonary veins flowing spectrum reflected the global left ventricular systolic and diastolic function. The Vs, Ve, Va, a, PVd/PVa ratio, LVEF, Sis, Sid and their correlations between normal subjects and patients with DCM were compared and analyzed. Results Vs, Ve, Va, a, PVd/PVa, Sis and Sid in patients with DCM were lower than those in normal persons. There were significant relations between Sis and a （ r = 0. 6142, P 〈 0. 05）, Ve/Va and Sid （ r = 0. 6271, P 〈 0. 05 ）. Conclusions QTVI offer a newer method which has a higher sensitivity and accuracy in evaluating the left venticle regional systolic and diastolic function in DCM patients. There was significant relation between regional cardiac function and left venticle sphericity. （ S Chin J Cardiol 2009; 10（1） ： 9 -14）展开更多
According to the characteristics of a complex cover panel, its geometry shape is described by the NURBS surface with great description capability. With the reference to the surface classification determined by Gauss c...According to the characteristics of a complex cover panel, its geometry shape is described by the NURBS surface with great description capability. With the reference to the surface classification determined by Gauss curvature, the proportion of the mid-surface area between before and after being developed is derived from the displacement variation of the mid-surface in the normal vector direction of the sheet metal during the sheet metal forming process. Hereby, based on the curve development theory in differential geometry, a novel diagonal point by point surface development method is put forward to estimate a complex cover panel＇s blank contour efficiently. By comparing the sample＇s development result of diagonal point by point surface development method with that of available one-step method, the validity of the proposed surface development method is verified.展开更多
The modes of grain selection in spiral selector were investigated by both a ProCAST simulation and experimental confirmation.The results show that the efficiency of grain selection in starter block is associated with ...The modes of grain selection in spiral selector were investigated by both a ProCAST simulation and experimental confirmation.The results show that the efficiency of grain selection in starter block is associated with the geometry shape.At the early stage of grain selection,the optimization of grain orientation is dominated by competitive grain growth,but the optimization of grain orientation in starter block is gradually dominated by geometry shape at the later stage of grain selection.Besides,the spiral part could also optimize the orientation of the selected single crystal when the initial angle is large enough,and the single crystal selection in spiral parts with different pitch lengths and initial angles is dominated by different modes.The simulation results agree well with experimental ones.展开更多
文摘To assess the left ventricle regional systolic and diastolic function, left ventricle geometry and left venticle sphericity indexes in patients with dilated cardiomyopathy （DCM） by quantitative tissue velocity imaging （QTVI）. Methods Thirty normal subjects and 52 DCM patients underwent QTVI and colour Doppler flow imaging study in order to measure the left ventricular regional function along left ventricle apical long-axis view and the left ventricle geometry. Peak tissue velocities of left venticle regional muscular tissue during systole （ Vs）, systolic acceleration （ a）, early diastole（Ve） and left atrium contraction（Va） along left venticle apical long axis view were measured. The indexes of left ventricular regional systolic and diastolic function were mearsured at the same time. The left ventricle geometry shape was reflected from the systolic and diastolic sphericity index （Sis and Sid）, the left ventricular ejection fraction （LVEF） and D wave / A wave （PVd/PVa） of pulmonary veins flowing spectrum reflected the global left ventricular systolic and diastolic function. The Vs, Ve, Va, a, PVd/PVa ratio, LVEF, Sis, Sid and their correlations between normal subjects and patients with DCM were compared and analyzed. Results Vs, Ve, Va, a, PVd/PVa, Sis and Sid in patients with DCM were lower than those in normal persons. There were significant relations between Sis and a （ r = 0. 6142, P 〈 0. 05）, Ve/Va and Sid （ r = 0. 6271, P 〈 0. 05 ）. Conclusions QTVI offer a newer method which has a higher sensitivity and accuracy in evaluating the left venticle regional systolic and diastolic function in DCM patients. There was significant relation between regional cardiac function and left venticle sphericity. （ S Chin J Cardiol 2009; 10（1） ： 9 -14）
文摘According to the characteristics of a complex cover panel, its geometry shape is described by the NURBS surface with great description capability. With the reference to the surface classification determined by Gauss curvature, the proportion of the mid-surface area between before and after being developed is derived from the displacement variation of the mid-surface in the normal vector direction of the sheet metal during the sheet metal forming process. Hereby, based on the curve development theory in differential geometry, a novel diagonal point by point surface development method is put forward to estimate a complex cover panel＇s blank contour efficiently. By comparing the sample＇s development result of diagonal point by point surface development method with that of available one-step method, the validity of the proposed surface development method is verified.
基金supported by the National Basic Research Program(973 Program) of China under Grant No.2010CB631200(2010CB631206)the National Natural Science Foundation of China(NSFC) under Grant No.50801061,No.50931004,No.51071165the fund of the State Key Laboratory of Solidification Processing in NWPU under Grant No.SKLSP201112
文摘The modes of grain selection in spiral selector were investigated by both a ProCAST simulation and experimental confirmation.The results show that the efficiency of grain selection in starter block is associated with the geometry shape.At the early stage of grain selection,the optimization of grain orientation is dominated by competitive grain growth,but the optimization of grain orientation in starter block is gradually dominated by geometry shape at the later stage of grain selection.Besides,the spiral part could also optimize the orientation of the selected single crystal when the initial angle is large enough,and the single crystal selection in spiral parts with different pitch lengths and initial angles is dominated by different modes.The simulation results agree well with experimental ones.
