目的探讨经桡动脉入路脑血管造影中持续动脉压监测在发现导管扭转打结中的作用。方法回顾性分析2017年7月至2019年12月接受经桡动脉入路脑血管造影的116例缺血性脑血管病患者的临床病例资料,其中80例造影过程中接受持续动脉压监测(测压...目的探讨经桡动脉入路脑血管造影中持续动脉压监测在发现导管扭转打结中的作用。方法回顾性分析2017年7月至2019年12月接受经桡动脉入路脑血管造影的116例缺血性脑血管病患者的临床病例资料,其中80例造影过程中接受持续动脉压监测(测压组),另36例作为无测压组。在操作过程中,动脉压力差变小甚至曲线变平提示导管某段发生扭转打结。比较两组患者的性别、年龄、主动脉弓型等基本临床病例信息,手术适应证、透视时间、手术时间,以及造影过程中导管扭转打结发生率。结果两组患者性别、年龄、主动脉弓型、透视时间、手术时间差异均无统计学意义。测压组动脉导管扭转打结发生率低于无测压组(0 vs 8.33%,P=0.047)。结论持续动脉压力监测有助于发现早期桡动脉入路脑血管造影过程中导管扭转打结,进而降低相关并发症的发生,值得推广应用。展开更多
Internal solitary waves(ISWs)change the roughness of the sea surface,thus producing dark and bright bands in optical images.However,reasons for changes in imaging characteristics with the solar zenith angle remain unc...Internal solitary waves(ISWs)change the roughness of the sea surface,thus producing dark and bright bands in optical images.However,reasons for changes in imaging characteristics with the solar zenith angle remain unclear.In this paper,the optical imaging pattern of ISWs in sunglint under different zenith angles of the light source is investigated by collecting optical images of ISWs through physical simulation.The experiment involves setting 10 zenith angles of the light source,which are divided into area a the optical images of ISWs in the three areas show dark-bright mode,single bright band,and bright-dark mode,which are consistent with those observed by optical remote sensing.In addition,this study analyzed the percentage of the dark and bright areas of the bands and the change in the relative gray difference and found changes in both areas under different zenith angles of the light source.The MODIS and ASAR images display a similar brightness-darkness distance of the same ISWs.Therefore,the relationship between the brightness-darkness distance and the characteristic half-width of ISWs is determined in accordance with the eKdV theory and the imaging mechanism of ISWs of the SAR image.Overall,the relationship between them in the experiment is almost consistent with the theoretical result.展开更多
软开关技术具有快速动态响应、高稳定性、易控制、低损耗等特点,广泛应用于开关电源设备中。然而,功率开关期间快速的电流、电压转换对软开关降压转换器的传导噪声仍然有很大影响。针对上述问题,提出一种新型ZVS(Zero Voltage Switching...软开关技术具有快速动态响应、高稳定性、易控制、低损耗等特点,广泛应用于开关电源设备中。然而,功率开关期间快速的电流、电压转换对软开关降压转换器的传导噪声仍然有很大影响。针对上述问题,提出一种新型ZVS(Zero Voltage Switching)全波型软开关降压转换器拓扑,分析了此转换器的稳定性,运用扩展频谱时钟技术,采用调制谐振上升沿时间方法,不仅降低了转换器输出纹波,而且有效降低了转换器的电磁干扰(ElectroMagnetic Interference,EMI)噪声,通过仿真试验验证了该转换器的性能,与硬开关相比,EMI减低了22 dB,输出纹波减小到4.7 mV。展开更多
文摘目的探讨经桡动脉入路脑血管造影中持续动脉压监测在发现导管扭转打结中的作用。方法回顾性分析2017年7月至2019年12月接受经桡动脉入路脑血管造影的116例缺血性脑血管病患者的临床病例资料,其中80例造影过程中接受持续动脉压监测(测压组),另36例作为无测压组。在操作过程中,动脉压力差变小甚至曲线变平提示导管某段发生扭转打结。比较两组患者的性别、年龄、主动脉弓型等基本临床病例信息,手术适应证、透视时间、手术时间,以及造影过程中导管扭转打结发生率。结果两组患者性别、年龄、主动脉弓型、透视时间、手术时间差异均无统计学意义。测压组动脉导管扭转打结发生率低于无测压组(0 vs 8.33%,P=0.047)。结论持续动脉压力监测有助于发现早期桡动脉入路脑血管造影过程中导管扭转打结,进而降低相关并发症的发生,值得推广应用。
基金National Natural Science Foundation of China (Nos.61871353 and 42006164)for their support。
文摘Internal solitary waves(ISWs)change the roughness of the sea surface,thus producing dark and bright bands in optical images.However,reasons for changes in imaging characteristics with the solar zenith angle remain unclear.In this paper,the optical imaging pattern of ISWs in sunglint under different zenith angles of the light source is investigated by collecting optical images of ISWs through physical simulation.The experiment involves setting 10 zenith angles of the light source,which are divided into area a the optical images of ISWs in the three areas show dark-bright mode,single bright band,and bright-dark mode,which are consistent with those observed by optical remote sensing.In addition,this study analyzed the percentage of the dark and bright areas of the bands and the change in the relative gray difference and found changes in both areas under different zenith angles of the light source.The MODIS and ASAR images display a similar brightness-darkness distance of the same ISWs.Therefore,the relationship between the brightness-darkness distance and the characteristic half-width of ISWs is determined in accordance with the eKdV theory and the imaging mechanism of ISWs of the SAR image.Overall,the relationship between them in the experiment is almost consistent with the theoretical result.
