We investigate the propagation of dark solitons in a nonlinear dissipative electrical line. We show that the dynamics of the line is reduced to an expanded Korteweg-de Vries-Burgers (KdVB) equation. By applying the pe...We investigate the propagation of dark solitons in a nonlinear dissipative electrical line. We show that the dynamics of the line is reduced to an expanded Korteweg-de Vries-Burgers (KdVB) equation. By applying the perturbation theory to the KdVB equation, we obtain soliton-like pulse solutions. The numerical simulations of the discrete equation are carried out and show the possibility of the founding solution to spread through the line. The effect of the dissipation through soliton is also shown. A chaotic-like behavior can take place in the system during the propagation of dark solitons through the line.展开更多
Chlorophyll, one of the major chloroplast components for photosynthesis, has a positive relationship with the photosynthetic rate. The chlorophyll content is an important assessment parameter in agronomy and plant bio...Chlorophyll, one of the major chloroplast components for photosynthesis, has a positive relationship with the photosynthetic rate. The chlorophyll content is an important assessment parameter in agronomy and plant biology research. This study was conducted to evaluate the natural variation in the chlorophyll content and to determine the differential response of the chlorophyll concentration to dark treatment in a natural population containing 139 maize inbreds. A five-fold higher chlorophyll concentration was measured in the light compared with the dark. Meanwhile, the wide variation in the chlorophyll concentration showed the differential response of the natural maize population to dark. Finally, we identified some inbreds that were highly sensitive to the dark with more than 70% difference between the light and dark treatment, such as Dan598, Zheng29, Zheng35, DH29, and R08, as well as some inbreds that had lower sensitivity to the dark, with less than 35% difference in the chlorophyll content between the light and dark treatment, such as Chuan48-2, 4F1, 303WX, 9642, and LY042.展开更多
This study presents results on detecting neutral atomic hydrogen(H I)21 cm absorption in the spectrum of PKS PKS1413+13 at redshift z=0.24670041.The observation was conducted by FAST,with a spectral resolution of10 Hz...This study presents results on detecting neutral atomic hydrogen(H I)21 cm absorption in the spectrum of PKS PKS1413+13 at redshift z=0.24670041.The observation was conducted by FAST,with a spectral resolution of10 Hz,using 10 minutes of observing time.The global spectral profile is examined by modeling the absorption line using a single Gaussian function with a resolution of 10 kHz within a 2 MHz bandwidth.The goal is to determine the rate of the latest cosmic acceleration by directly measuring the redshift evolution of the H I 21 cm absorption line with Hubble flow toward a common background quasar over a decade or longer time span.This will serve as a detectable signal generated by the accelerated expansion of the Universe at redshift z<1,referred to as redshift drift z(5)or the SL effect.The measured H I gas column density in this DLA system is approximately equivalent to the initial observation value,considering uncertainties of the spin temperature of a spiral host galaxy.The high signal-to-noise ratio of 57,obtained at a 10 kHz resolution,strongly supports the feasibility of using the H I 21 cm absorption line in DLA systems to accurately measure the redshift drift rate at a precision level of around 10~(-10)per decade.展开更多
Theory and observations concerning the cosmic reionization epoch are briefly discussed in the context of recent observations attributed to dark matter. A case is made that cold ground state interstellar atomic hydroge...Theory and observations concerning the cosmic reionization epoch are briefly discussed in the context of recent observations attributed to dark matter. A case is made that cold ground state interstellar atomic hydrogen of average density of about one atom per cubic centimeter (1.67 × 10-21?kg·m-3?or 1.67 × 10-24?g·cm-3) appears to be the most likely candidate to explain these observations.展开更多
文摘We investigate the propagation of dark solitons in a nonlinear dissipative electrical line. We show that the dynamics of the line is reduced to an expanded Korteweg-de Vries-Burgers (KdVB) equation. By applying the perturbation theory to the KdVB equation, we obtain soliton-like pulse solutions. The numerical simulations of the discrete equation are carried out and show the possibility of the founding solution to spread through the line. The effect of the dissipation through soliton is also shown. A chaotic-like behavior can take place in the system during the propagation of dark solitons through the line.
文摘Chlorophyll, one of the major chloroplast components for photosynthesis, has a positive relationship with the photosynthetic rate. The chlorophyll content is an important assessment parameter in agronomy and plant biology research. This study was conducted to evaluate the natural variation in the chlorophyll content and to determine the differential response of the chlorophyll concentration to dark treatment in a natural population containing 139 maize inbreds. A five-fold higher chlorophyll concentration was measured in the light compared with the dark. Meanwhile, the wide variation in the chlorophyll concentration showed the differential response of the natural maize population to dark. Finally, we identified some inbreds that were highly sensitive to the dark with more than 70% difference between the light and dark treatment, such as Dan598, Zheng29, Zheng35, DH29, and R08, as well as some inbreds that had lower sensitivity to the dark, with less than 35% difference in the chlorophyll content between the light and dark treatment, such as Chuan48-2, 4F1, 303WX, 9642, and LY042.
基金supported by the National SKA Program of China(2022SKA0110202)the National Natural Science Foundation of China(grants No.11929301)。
文摘This study presents results on detecting neutral atomic hydrogen(H I)21 cm absorption in the spectrum of PKS PKS1413+13 at redshift z=0.24670041.The observation was conducted by FAST,with a spectral resolution of10 Hz,using 10 minutes of observing time.The global spectral profile is examined by modeling the absorption line using a single Gaussian function with a resolution of 10 kHz within a 2 MHz bandwidth.The goal is to determine the rate of the latest cosmic acceleration by directly measuring the redshift evolution of the H I 21 cm absorption line with Hubble flow toward a common background quasar over a decade or longer time span.This will serve as a detectable signal generated by the accelerated expansion of the Universe at redshift z<1,referred to as redshift drift z(5)or the SL effect.The measured H I gas column density in this DLA system is approximately equivalent to the initial observation value,considering uncertainties of the spin temperature of a spiral host galaxy.The high signal-to-noise ratio of 57,obtained at a 10 kHz resolution,strongly supports the feasibility of using the H I 21 cm absorption line in DLA systems to accurately measure the redshift drift rate at a precision level of around 10~(-10)per decade.
文摘Theory and observations concerning the cosmic reionization epoch are briefly discussed in the context of recent observations attributed to dark matter. A case is made that cold ground state interstellar atomic hydrogen of average density of about one atom per cubic centimeter (1.67 × 10-21?kg·m-3?or 1.67 × 10-24?g·cm-3) appears to be the most likely candidate to explain these observations.
