The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated.Through the ultrasonic signals emitted by the filaments,it is observed that in...The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated.Through the ultrasonic signals emitted by the filaments,it is observed that increasing turbulence intensity and an expanding turbulence active region cause an increase in the start position of the filament and a decrease in filament length,which can be well explained by theoretical calculation.It is also observed that the random perturbation of the air refractive index caused by atmospheric turbulence expands the spot size of the filament.Additionally,when the turbulence refractive index structure constant reaches 8.37×10^(-12)m^(-2/3),multiple filaments are formed.Furthermore,the standard deviation of the transverse displacement of filament is found to be proportional to the square root of the turbulent structure constant under the experimental turbulence parameters in this paper.These results contribute to the study of femtosecond laser propagation mechanisms in complex atmospheric turbulence conditions.展开更多
Research of superconducting nanowire singlephoton detectors(SNSPDs) has been progressing rapidly in recent years. The combined properties of high efficiency,low noise, and fast speed of SNSPDs permit its applications ...Research of superconducting nanowire singlephoton detectors(SNSPDs) has been progressing rapidly in recent years. The combined properties of high efficiency,low noise, and fast speed of SNSPDs permit its applications ranging from long-distance quantum teleportation to moonto-earth optical communications. Here we briefly discussed recent progress of SNSPDs, in particular(1) tungstensilicide SNSPDs,(2) waveguide-integrated SNSPDs, and(3) a few applied demonstrations.展开更多
Pregnant women are generally more susceptible to viral infection.Although the impact of SARS-CoV-2 in pregnancy remains to be determined,evidence indicates that the risk factors for severe COVID-19 are similar in preg...Pregnant women are generally more susceptible to viral infection.Although the impact of SARS-CoV-2 in pregnancy remains to be determined,evidence indicates that the risk factors for severe COVID-19 are similar in pregnancy to the general population.Here we systemically analyzed the clinical characteristics of pregnant and non-pregnant female COVID-19 patients who were hospitalized during the same period and found that pregnant patients developed marked lymphopenia and higher inflammation evident by higher C-reactive protein and IL-6.To elucidate the pathways that might contribute to immunopathology or protective immunity against COVID-19 during pregnancy,we applied single-cell mRNA sequencing to profile peripheral blood mononuclear cells from four pregnant and six non-pregnant female patients after recovery along with four pregnant and three non-pregnant healthy donors.We found normal clonal expansion of T cells in the pregnant patients,heightened activation and chemotaxis in NK,NKT,and MAIT cells,and differential interferon responses in the monocyte compartment.Our data present a unique feature in both innate and adaptive immune responses in pregnant patients recovered from COVID-19.展开更多
基金supported by the National Key Research and Development Program of China(No.2018YFB0504400)the Fundamental Research Funds for the Central Universities(No.63223052)。
文摘The effects of turbulence intensity and turbulence region on the distribution of femtosecond laser filaments are experimentally elaborated.Through the ultrasonic signals emitted by the filaments,it is observed that increasing turbulence intensity and an expanding turbulence active region cause an increase in the start position of the filament and a decrease in filament length,which can be well explained by theoretical calculation.It is also observed that the random perturbation of the air refractive index caused by atmospheric turbulence expands the spot size of the filament.Additionally,when the turbulence refractive index structure constant reaches 8.37×10^(-12)m^(-2/3),multiple filaments are formed.Furthermore,the standard deviation of the transverse displacement of filament is found to be proportional to the square root of the turbulent structure constant under the experimental turbulence parameters in this paper.These results contribute to the study of femtosecond laser propagation mechanisms in complex atmospheric turbulence conditions.
基金supported by the National Natural Science Foundation of China(61505141 and 11527808)the National Thousand Talents Plan for Young Professionals
文摘Research of superconducting nanowire singlephoton detectors(SNSPDs) has been progressing rapidly in recent years. The combined properties of high efficiency,low noise, and fast speed of SNSPDs permit its applications ranging from long-distance quantum teleportation to moonto-earth optical communications. Here we briefly discussed recent progress of SNSPDs, in particular(1) tungstensilicide SNSPDs,(2) waveguide-integrated SNSPDs, and(3) a few applied demonstrations.
基金This work was supported by the National Key Research and Development Program of China(2017YFA0106800 to L.C.and J.-w.L.and 2019YFC1005202 to K.L.).
文摘Pregnant women are generally more susceptible to viral infection.Although the impact of SARS-CoV-2 in pregnancy remains to be determined,evidence indicates that the risk factors for severe COVID-19 are similar in pregnancy to the general population.Here we systemically analyzed the clinical characteristics of pregnant and non-pregnant female COVID-19 patients who were hospitalized during the same period and found that pregnant patients developed marked lymphopenia and higher inflammation evident by higher C-reactive protein and IL-6.To elucidate the pathways that might contribute to immunopathology or protective immunity against COVID-19 during pregnancy,we applied single-cell mRNA sequencing to profile peripheral blood mononuclear cells from four pregnant and six non-pregnant female patients after recovery along with four pregnant and three non-pregnant healthy donors.We found normal clonal expansion of T cells in the pregnant patients,heightened activation and chemotaxis in NK,NKT,and MAIT cells,and differential interferon responses in the monocyte compartment.Our data present a unique feature in both innate and adaptive immune responses in pregnant patients recovered from COVID-19.
