Conventionally,the spatially structured light beams produced by metasurfaces primarily highlight the polarization modulation of the beams propagating along the optical axis or the beams'spatial transmission trajec...Conventionally,the spatially structured light beams produced by metasurfaces primarily highlight the polarization modulation of the beams propagating along the optical axis or the beams'spatial transmission trajectory.In particular,along the optical axis,the polarization state is either constant or varies continuously in each output plane.Here,we develop innovative spatially structured light beams with continually changing polarization along any arbitrary spatial transmission trajectories.With tri-layer metallic metasurfaces,the geometric characteristics of each layer structure can be adjusted to modulate the phase and polarization state of the incident terahertz(THz)wave.The beam will converge to the predefined trajectory along several paths to generate a Bessel-like beam with longitudinal polarization changes.We demonstrate the versatility of the approach by designing two THz-band structured light beams with varying polarization states along the spatial helical transmission trajectory.Continuous linear polarization changes and linear polarization to right circular polarization(RCP)and back to linear polarization changes are realized respectively.The experimental results are basically consistent with the simulated results.Our proposal for arbitrary trajectory structured light beams with longitudinally varying polarization offers a practical method for continuously regulating the characteristics of spatial structured light beams with non-axial transmission.This technique has potential uses in optical encryption,particle manipulation,and biomedical imaging.展开更多
针对LVDT在使用中重复性受外界因素影响的问题,进行了理论分析与软件仿真,认为LVDT的铁心受干扰时会产生径向跳动,从几何关系与磁场两方面使测量结果产生误差。文中设计了LVDT重复性测试系统,在LVDT量程范围内选取5、15、25 mm 3个测量...针对LVDT在使用中重复性受外界因素影响的问题,进行了理论分析与软件仿真,认为LVDT的铁心受干扰时会产生径向跳动,从几何关系与磁场两方面使测量结果产生误差。文中设计了LVDT重复性测试系统,在LVDT量程范围内选取5、15、25 mm 3个测量点进行测试,结果表明理论分析与实际测试具备良好的一致性。为提高LVDT的重复性,提出用精密直线轴承限制LVDT铁心的径向运动。优化后,5、15、25 mm处测量值的重复性标准差分别从0.07323、0.12633、0.15966 mm降低到0.03757、0.04868、0.04301 mm,测量值的离散程度明显减小,验证了优化方法的可行性和有效性。展开更多
目的:观察经皮后凸椎体成形术(PKP)联合术中胸椎旁神经阻滞治疗骨质疏松胸椎压缩性骨折(OTCF)的临床疗效。方法:将50例OTCF伴非轴性痛患者根据术中是否行胸椎旁神经阻滞随机分为两组,观察组(PKP联合胸椎旁神经阻滞)和对照组(单纯PKP)各2...目的:观察经皮后凸椎体成形术(PKP)联合术中胸椎旁神经阻滞治疗骨质疏松胸椎压缩性骨折(OTCF)的临床疗效。方法:将50例OTCF伴非轴性痛患者根据术中是否行胸椎旁神经阻滞随机分为两组,观察组(PKP联合胸椎旁神经阻滞)和对照组(单纯PKP)各25例。比较两组患者术前及术后1天、1周、1月及3月胸背肋间痛、腰椎功能及患者满意度情况,分别采用视觉模拟量表(VAS)评分、Oswestry功能障碍指数(ODI)及患者满意度测评进行评价。结果:两组患者术后1天、1周、1月、3月胸背肋间痛VAS评分及ODI评分均呈明显下降趋势(均P<0.05)。观察组术后1天(2.72±1.04 vs 3.36±1.13)及术后1周(2.44±0.94 vs 2.96±1.11)VAS评分明显低于对照组(均P<0.05),两组患者各时间点ODI评分比较无明显差异。术后1天(92%vs 68%)及术后1周(100%vs 84%)患者满意度明显高于对照组(均P<0.05)。结论:PKP联合术中胸椎旁神经阻滞可有效缓解OTCF患者术后早期非轴性疼痛程度,提高患者满意度。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12074094 and 121774271)the Sino-German Mobility Program of the Sino-German Center for Science Funding(Grant No.M-0225)the Capacity Building for Science&Technology Innovation-Fundamental Scientific Research Funds(Grant No.00820531120017).
文摘Conventionally,the spatially structured light beams produced by metasurfaces primarily highlight the polarization modulation of the beams propagating along the optical axis or the beams'spatial transmission trajectory.In particular,along the optical axis,the polarization state is either constant or varies continuously in each output plane.Here,we develop innovative spatially structured light beams with continually changing polarization along any arbitrary spatial transmission trajectories.With tri-layer metallic metasurfaces,the geometric characteristics of each layer structure can be adjusted to modulate the phase and polarization state of the incident terahertz(THz)wave.The beam will converge to the predefined trajectory along several paths to generate a Bessel-like beam with longitudinal polarization changes.We demonstrate the versatility of the approach by designing two THz-band structured light beams with varying polarization states along the spatial helical transmission trajectory.Continuous linear polarization changes and linear polarization to right circular polarization(RCP)and back to linear polarization changes are realized respectively.The experimental results are basically consistent with the simulated results.Our proposal for arbitrary trajectory structured light beams with longitudinally varying polarization offers a practical method for continuously regulating the characteristics of spatial structured light beams with non-axial transmission.This technique has potential uses in optical encryption,particle manipulation,and biomedical imaging.
文摘目的:观察经皮后凸椎体成形术(PKP)联合术中胸椎旁神经阻滞治疗骨质疏松胸椎压缩性骨折(OTCF)的临床疗效。方法:将50例OTCF伴非轴性痛患者根据术中是否行胸椎旁神经阻滞随机分为两组,观察组(PKP联合胸椎旁神经阻滞)和对照组(单纯PKP)各25例。比较两组患者术前及术后1天、1周、1月及3月胸背肋间痛、腰椎功能及患者满意度情况,分别采用视觉模拟量表(VAS)评分、Oswestry功能障碍指数(ODI)及患者满意度测评进行评价。结果:两组患者术后1天、1周、1月、3月胸背肋间痛VAS评分及ODI评分均呈明显下降趋势(均P<0.05)。观察组术后1天(2.72±1.04 vs 3.36±1.13)及术后1周(2.44±0.94 vs 2.96±1.11)VAS评分明显低于对照组(均P<0.05),两组患者各时间点ODI评分比较无明显差异。术后1天(92%vs 68%)及术后1周(100%vs 84%)患者满意度明显高于对照组(均P<0.05)。结论:PKP联合术中胸椎旁神经阻滞可有效缓解OTCF患者术后早期非轴性疼痛程度,提高患者满意度。
