Atmospheric effects on interferometric synthetic aperture radar(InSAR) measurements are quantitatively studied based on a tandem pair of SAR data and a month-long continuous GPS tracking data obtained at six stations....Atmospheric effects on interferometric synthetic aperture radar(InSAR) measurements are quantitatively studied based on a tandem pair of SAR data and a month-long continuous GPS tracking data obtained at six stations. Differential atmospheric signals extracted from the SAR data for two selected areas show apparent power law characteristics. The RMS values of the signals are 2.04 and 3.66 rad respectively for the two areas. These differential delays can potentially cause in the two areas peak-to-peak deformation errors of 3.64 and 6.52cm, respectively, at the 95% confidence level and Gaussian distribution. The respective potential peak-to-peak DEM errors are 123 and 221 m. The GPS tropospheric total zenith delays estimate indicates that a peak-to-peak error of about 7.8cm can potentially be caused in a SAR interferogram with only 1 d interval at the 95% confidence level. The error increases to about 9.6cm for 10 d interval. The potential peak-to-peak DEM and deformation errors estimated from GPS total zenith delay measurements are however quite similar to those estimated from InSAR data. This provides us with a useful tool to pre-estimate the potential atmospheric effects in a SAR interferogram before we order the SAR images. Nevertheless, the results reveal that even in a small area the atmospheric delays can obscure centimetre level ground displacements and introduce a few hundred meters of errors to derived DEM.展开更多
目的研究腰硬联合麻醉对全髋关节置换术患者血流动力学及苏醒延迟的影响。方法回顾性分析2013年9月至2015年9月阆中市人民医院接诊的80例行全髋关节置换术患者的临床资料,按照治疗方法不同分为观察组和对照组,各40例。对照组采用静脉复...目的研究腰硬联合麻醉对全髋关节置换术患者血流动力学及苏醒延迟的影响。方法回顾性分析2013年9月至2015年9月阆中市人民医院接诊的80例行全髋关节置换术患者的临床资料,按照治疗方法不同分为观察组和对照组,各40例。对照组采用静脉复合全身麻醉,咪达唑仑0.05~0.10 mg/kg、舒芬太尼3~4μg/kg、丙泊酚1 mg/kg、维库溴铵0.12 mg/kg插管麻醉;观察组采用腰硬联合麻醉,布比卡因0.5%2 m L、葡萄糖10%1 m L穿刺针进行麻醉。观察两组患者麻醉前(T_1)、麻醉后(T_2)、插管后(T_3)、切皮时(T_4)、拔管时(T_5)血流动力学变化,以及自主呼吸恢复时间、拔管时间、麻醉苏醒时间、麻醉情况与躁动发生率、不良反应的情况。结果两组患者在T_1无明显差异;T_2、T_3、T_4、T_5时段,两组患者均心率、收缩压、舒张压均呈不同程度变化,观察组T_2、T_3、T_4、T_5时段心率、收缩压、舒张压变化较对照组小(P<0.01),两组患者各指标组间、时点间、组间·时点间交互作用比较差异有统计学意义(P<0.01)。观察组自主呼吸恢复时间、拔管时间、苏醒时间均短于对照组[(4.7±1.2)min比(9.8±3.1)min,(7.8±2.2)min比(15.8±3.2)min,(16.2±5.2)min比(16.2±5.2)min](P<0.01);观察组麻醉用药量、起效时间、阻滞完全时间少于对照组[(15±3)mg比(138±24)mg,(46±12)s比(241±36)s,(14±3)min比(22±6)min],躁动发生率短于对照组[22.5%(9/40)比2.5%(1/40)](P<0.05);观察组不良反应总发生率低于对照组[7.5%(3/40)比35.0%(14/40)](P<0.05)。结论腰硬联合麻醉能够减少全髋关节置换术患者的血流动力学波动,不会造成患者苏醒延迟,减少患者的术后并发症发生。展开更多
文摘Atmospheric effects on interferometric synthetic aperture radar(InSAR) measurements are quantitatively studied based on a tandem pair of SAR data and a month-long continuous GPS tracking data obtained at six stations. Differential atmospheric signals extracted from the SAR data for two selected areas show apparent power law characteristics. The RMS values of the signals are 2.04 and 3.66 rad respectively for the two areas. These differential delays can potentially cause in the two areas peak-to-peak deformation errors of 3.64 and 6.52cm, respectively, at the 95% confidence level and Gaussian distribution. The respective potential peak-to-peak DEM errors are 123 and 221 m. The GPS tropospheric total zenith delays estimate indicates that a peak-to-peak error of about 7.8cm can potentially be caused in a SAR interferogram with only 1 d interval at the 95% confidence level. The error increases to about 9.6cm for 10 d interval. The potential peak-to-peak DEM and deformation errors estimated from GPS total zenith delay measurements are however quite similar to those estimated from InSAR data. This provides us with a useful tool to pre-estimate the potential atmospheric effects in a SAR interferogram before we order the SAR images. Nevertheless, the results reveal that even in a small area the atmospheric delays can obscure centimetre level ground displacements and introduce a few hundred meters of errors to derived DEM.
文摘目的研究腰硬联合麻醉对全髋关节置换术患者血流动力学及苏醒延迟的影响。方法回顾性分析2013年9月至2015年9月阆中市人民医院接诊的80例行全髋关节置换术患者的临床资料,按照治疗方法不同分为观察组和对照组,各40例。对照组采用静脉复合全身麻醉,咪达唑仑0.05~0.10 mg/kg、舒芬太尼3~4μg/kg、丙泊酚1 mg/kg、维库溴铵0.12 mg/kg插管麻醉;观察组采用腰硬联合麻醉,布比卡因0.5%2 m L、葡萄糖10%1 m L穿刺针进行麻醉。观察两组患者麻醉前(T_1)、麻醉后(T_2)、插管后(T_3)、切皮时(T_4)、拔管时(T_5)血流动力学变化,以及自主呼吸恢复时间、拔管时间、麻醉苏醒时间、麻醉情况与躁动发生率、不良反应的情况。结果两组患者在T_1无明显差异;T_2、T_3、T_4、T_5时段,两组患者均心率、收缩压、舒张压均呈不同程度变化,观察组T_2、T_3、T_4、T_5时段心率、收缩压、舒张压变化较对照组小(P<0.01),两组患者各指标组间、时点间、组间·时点间交互作用比较差异有统计学意义(P<0.01)。观察组自主呼吸恢复时间、拔管时间、苏醒时间均短于对照组[(4.7±1.2)min比(9.8±3.1)min,(7.8±2.2)min比(15.8±3.2)min,(16.2±5.2)min比(16.2±5.2)min](P<0.01);观察组麻醉用药量、起效时间、阻滞完全时间少于对照组[(15±3)mg比(138±24)mg,(46±12)s比(241±36)s,(14±3)min比(22±6)min],躁动发生率短于对照组[22.5%(9/40)比2.5%(1/40)](P<0.05);观察组不良反应总发生率低于对照组[7.5%(3/40)比35.0%(14/40)](P<0.05)。结论腰硬联合麻醉能够减少全髋关节置换术患者的血流动力学波动,不会造成患者苏醒延迟,减少患者的术后并发症发生。
