本文设计了由不对称半圆柱对阵列组成的全介质超构表面,获得了两个高品质因子的准连续域束缚态模式(quasi-bound states in the continuum,QBIC).通过选择不同形式的对称破缺,在近红外频段均可产生两个稳健的QBIC,并且二者的谐振波长、...本文设计了由不对称半圆柱对阵列组成的全介质超构表面,获得了两个高品质因子的准连续域束缚态模式(quasi-bound states in the continuum,QBIC).通过选择不同形式的对称破缺,在近红外频段均可产生两个稳健的QBIC,并且二者的谐振波长、品质因子、偏振依赖等表现出不同的特性.模拟计算表明,通过测量两个QBIC的谐振波长,能够实现折射率和温度的双参数传感;通过调节不对称参数,利用QBIC的品质因子依赖于不对称参数的二次方反比关系,理论上能够提高品质因子到任意的数值,从而实现传感性能的提升和调节.该超构表面的折射率传感灵敏度、品质因子和优值分别达到194.7 nm/RIU,45829和8197,其温度传感灵敏度达到24 pm/℃.展开更多
The experimental studies of the wave breaking effects on freak wave generation are presented within a finite-depth random wave train in a laboratory wave tank. The main attention is paid to the abnormal index, AI = Hm...The experimental studies of the wave breaking effects on freak wave generation are presented within a finite-depth random wave train in a laboratory wave tank. The main attention is paid to the abnormal index, AI = Hmas/Hs, being used to characterize the freak waves, and the changes of the coefficient due to wave breaking. The results show that the occurrence probability of freak wave events in non-breaking waves is much larger than that in bleaking waves and such occurrence in deep water is larger than that in shallow water.展开更多
<strong>Background:</strong> Dry eye is characterized by tear film instability, decreased tear volume and a high Ocular Surface Disease Index (OSDI) score. Face masks have been linked to dry eye complaints...<strong>Background:</strong> Dry eye is characterized by tear film instability, decreased tear volume and a high Ocular Surface Disease Index (OSDI) score. Face masks have been linked to dry eye complaints in recent studies. <strong>Purpose:</strong> To evaluate the changes in tear-film status and Ocular Surface Disease Index (OSDI) score following prolonged use of face mask. <strong>Design:</strong> Cross-sectional study. <strong>Method:</strong> Patients between 18 to 70 years using masks regularly for at least 2 hours/day for at least 5 days/week from different eye-care centres in Dhaka were included. All subjects were divided into 4 groups. Mask use lasted approximately 2 hours/day in Group 1, 4 hours/day in Group 2, 6 hours/day in Group 3 and 8 hours or more/day in Group 4. Evaluation of symptoms, tear- film stability and tear volume was done by Ocular Surface Disease Index (OSDI) scores, Tear-film Break-Up Time (TBUT) and Schirmer-1 test. Average of right & left eye’s Tear-film Break Up time (TBUT) and Schirmer-1 value were noted. <strong>Results:</strong> Total 100 patients were enrolled (n = 100). The TBUT (p < 0.001) and Schirmer-1 measurement (p = 0.01) were significantly lesser and Ocular Surface Disease Index (OSDI) score were significantly higher in patients using face-masks for longer time (p < 0.001). <strong>Conclusion:</strong> Patients who wore masks for prolonged time had tear film instability, reduced tear volume and higher Ocular Surface Disease Index (OSDI) score.展开更多
文摘本文设计了由不对称半圆柱对阵列组成的全介质超构表面,获得了两个高品质因子的准连续域束缚态模式(quasi-bound states in the continuum,QBIC).通过选择不同形式的对称破缺,在近红外频段均可产生两个稳健的QBIC,并且二者的谐振波长、品质因子、偏振依赖等表现出不同的特性.模拟计算表明,通过测量两个QBIC的谐振波长,能够实现折射率和温度的双参数传感;通过调节不对称参数,利用QBIC的品质因子依赖于不对称参数的二次方反比关系,理论上能够提高品质因子到任意的数值,从而实现传感性能的提升和调节.该超构表面的折射率传感灵敏度、品质因子和优值分别达到194.7 nm/RIU,45829和8197,其温度传感灵敏度达到24 pm/℃.
基金supported by the National Natural Science Foundation of China (Grant No.50779004)
文摘The experimental studies of the wave breaking effects on freak wave generation are presented within a finite-depth random wave train in a laboratory wave tank. The main attention is paid to the abnormal index, AI = Hmas/Hs, being used to characterize the freak waves, and the changes of the coefficient due to wave breaking. The results show that the occurrence probability of freak wave events in non-breaking waves is much larger than that in bleaking waves and such occurrence in deep water is larger than that in shallow water.
文摘<strong>Background:</strong> Dry eye is characterized by tear film instability, decreased tear volume and a high Ocular Surface Disease Index (OSDI) score. Face masks have been linked to dry eye complaints in recent studies. <strong>Purpose:</strong> To evaluate the changes in tear-film status and Ocular Surface Disease Index (OSDI) score following prolonged use of face mask. <strong>Design:</strong> Cross-sectional study. <strong>Method:</strong> Patients between 18 to 70 years using masks regularly for at least 2 hours/day for at least 5 days/week from different eye-care centres in Dhaka were included. All subjects were divided into 4 groups. Mask use lasted approximately 2 hours/day in Group 1, 4 hours/day in Group 2, 6 hours/day in Group 3 and 8 hours or more/day in Group 4. Evaluation of symptoms, tear- film stability and tear volume was done by Ocular Surface Disease Index (OSDI) scores, Tear-film Break-Up Time (TBUT) and Schirmer-1 test. Average of right & left eye’s Tear-film Break Up time (TBUT) and Schirmer-1 value were noted. <strong>Results:</strong> Total 100 patients were enrolled (n = 100). The TBUT (p < 0.001) and Schirmer-1 measurement (p = 0.01) were significantly lesser and Ocular Surface Disease Index (OSDI) score were significantly higher in patients using face-masks for longer time (p < 0.001). <strong>Conclusion:</strong> Patients who wore masks for prolonged time had tear film instability, reduced tear volume and higher Ocular Surface Disease Index (OSDI) score.
