ON THE FIRST EIGENVALUE OF THE MEAN FINSLER-LAPLACIAN

In this paper, we prove that several different definitions of the Finsler-Laplacian are equivalent. Then we prove that any Berwald metric is affinely equivalent to its mean metric and give some upper or lower bound estimates for the first eigenvalue of the mean Laplacian on Berwald manifolds, which generalize some results in Riemannian geometry.

Uniqueness Theorem of Algebroidal Function in the Unit Disc

In this paper, discussed are the problems about uniqueness of algebroidal functions in the unit disc with share-values in a sector domain instead of the whole disk. Results are obtained extending some uniqueness theorems of meromorphic functions.

Influencing Factors and Mortality Prediction of Covid-19 Contact Infection Rate in China

Taking the COVID-19 data from 2020-1-23 to 3-21 days released by the China Health Protection Committee as the sample,the hospital remaining rate,mortality rate and cure rate are selected as covariates,and the contact infection rate is used as response variable to establish a high precision ADL model,results of return substitution show that the predicted value of contact infection rate almost coincides with the sample value,and shows three stages of change characteristics.After March 1,2020,the overall trend is downward,stable below 12%.Main influencing factors of contact infection rate are analyzed quantitatively.Based on this,the ARIMA(1,2,2)model is established to analyze and predict the mortality change trend.The results showed that the domestic COVID-19 mortality rate is stable near 4%after 2020-3-27.

AGING PROPERTIES OF THE LIFETIME IN SIMPLE ADDITIVE DEGRADATION MODELS

This paper deals with the simple additive degradation models with single random effect. The authors further study the link between the aging property of the implied lifetime and that of the random variation. It is found that both the aging property of the random variation and the analytical behavior of the mean degradation path influence the aging behavior of the implied lifetime.

Moderate deviations for Euler-Maruyama approximation of Hull-White stochastic volatility model

We consider the Euler-Maruyama discretization of stochastic volatility model dSt = σtStdWt, dσt = ωσtdZt, t ∈ [0, T], which has been widely used in financial practice, where Wt, Zt, t ∈ [0, T], are two uncorrelated standard Brownian motions. Using asymptotic analysis techniques, the moderate deviation principles for log Sn （or log ｜Sn｜ in case Sn is negative） are obtained as n → ∞ under different discretization schemes for the asset price process St and the volatility process σt. Numerical simulations are presented to compare the convergence speeds in different schemes.

Effect of magnesium doping on the light-induced hydrophilicity of ZnO thin films

Undoped and Mg-doped ZnO thin films were deposited on Si（111） and quartz substrates by using the sol-gel method.Microstructure,surface topography and water contact angle of the thin films have been measured by X-ray diffraction（XRD）,an atomic force microscope（AFM） and water contact angle apparatus,respectively. The XRD results show that all the thin films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate.With the increase of Mg concentration,the RMS roughness increases from 2.14 to 9.56 nm and the contact angle of the un-irradiated thin films decreases from 89°to 82°. The wetting behavior of the resulting films can be reversibly switched from hydrophobic to hydrophilic,through alternation of UV illumination and dark storage.The light-induced efficiency of the thin films increases with the increase of Mg concentration.