Search

Multi-beam-pumped optical parametric amplification (OPA) may offer a solution for overcoming the limitations on the repetition rate and average power of ultraintense femtosecond lasers. However, multi-beam pumping scheme encounters challenges due to low conversion efficiency caused by parametric diffraction and inter-channel crosstalk, which are attributed to the presence of multi-idler-waves. This paper introduces and explores multi-beam-pumped quasi-parametric amplification (QPA) as an alternative approach to multi-beam-pumped OPA. We theoretically demonstrate that strong idler dissipation can significantly reduce inter-channel crosstalk and parametric diffraction in a two-beam-pumped QPA. These findings highlight the potential of multibeam-pumped QPA for efficiently amplifying femtosecond laser pulses to high average power levels with robustness.

Aim: In order to supply a scientific basis for uniting the normal reference value standard of hemoglobin of Chinese middlescent women., Methods: A research is made about the relationship between the normal reference value of 25,917 examples of hemoglobin of middlescent women and altitude in 268 areas in China, the normal reference values of hemoglobin of middlescent women are determined by the hemoglobincyanide method., Results: The correlation between the normal reference value of hemoglobin of middlescent women and altitude is quite significant (r = 0.827). By using the method of univariate linear regression analysis, one regression equation is inferred., Conclusion: If the altitude values are obtained in some areas, the normal reference value of hemoglobin of middlescent women of this area can be reckoned by using the regression equation. Furthermore, depending on the altitude, China can be divided into three districts: Qingzang District, Central District, and Eastern District.

The aim of this study was to provide a scientific basis for a unified standard of the reference value of healthy presenile human hematocrit in China. We studied the relationship between the reference values of healthy presenile human hematocrit, tested according to Wintrobe's laws, and five geographical factors. It was found that altitude is the most important factor affecting the reference value of the hematocrit. As the altitude gradually increases, the reference value of the hematocrit also increases. The relationship is quite significant. By using the method of stepwise regression analysis, two multivariate regression equations were deduced: Y1 = 39.7 + 0.00328X1 + 0.00169X2 + 0.00117X5 +/- 2.3, Y2 = 38.8 + 0.00275X1 + 0.000578X2 -0.00298X4 +/- 2.2 In these equations, Y1 is the reference value of presenile men's hematocrit (%); Y2 is the reference value of presenile women's hematocrit (%); X1 is altitude (m); X2 is the average annual hours of sunshine (h); X4 is the average annual temperature (degrees C), and X5 is the average annual precipitation (mm). If the geographical index values in a particular area in China are known, the reference value of presenile human hematocrit in this area can be calculated approximately by means of the regression equations., (Copyright 2002 Wiley‐Liss, Inc.)