太阳过渡区紫外光谱的观测与诊断

太阳过渡区是太阳色球层顶到日冕底部的大气薄层。厚度仅几百千米,但其间太阳等离子体参数变化剧烈。过渡区的辐射多为光学薄的远紫外、极紫外发射谱线和背景连续谱线。由于地球大气的吸收,过渡区紫外光谱需通过天基观测才能实现。近几十年来,星载仪器的成功发射为太阳过渡区的研究打开了新纪元。工作回顾了太阳过渡区紫外光谱的观测历史和各类星载仪器,特别介绍了近十几年几种重要的光谱仪器。详细阐述了过渡区紫外光谱的发生率、电子密度和电子温度的诊断原理。讨论了过渡区紫外谱线的形状,并以SOHO/SUMER光谱仪为例介绍了表征谱线的几种重要参量及其物理意义。     

The strong approximation property and the weak bounded approximation property

We show that the strong approximation property (strong AP) (respectively, strong CAP) and the weak bounded approximation property (respectively, weak BCAP) are equivalent for every Banach space. This gives a negative answer to Oja's conjecture. As a consequence, we show that each of the spaces _c0$c_0$ and _?1${?}_1$ has a subspace which has the AP but fails to have the strong AP.     

A Strong Maximum Principle for parabolic equations with the p-Laplacian

We prove the Strong Maximum Principle (SMP) under suitable assumptions for a class of quasilinear parabolic problems with the p  -Laplacian, p>1$p>1$, on bounded cylindrical domains of R^N+1${\mathbb{R}}^{N+1}$,

_∂tu−_Δpu−λ|u|^p−2u≥0,${\partial }_{t}u-{\mathrm{\Delta }}_{p}u-\lambda {|u|}^{p-2}u\ge 0,$

with nonnegative initial–boundary conditions and λ≤0$\lambda \le 0$, and we give some counterexamples to the SMP if some of our assumptions are violated. We show that the Hopf Maximum Principle holds for 1<p<2$1<p<2$, and give a counterexample to it for p>2$p>2$. Also the Weak Maximum Principle for λ≤_λ1$\lambda \le {\lambda }_1$ is established.     

Standard maximum likelihood drift parameter estimator in the homogeneous diffusion model is always strongly consistent

We consider the homogeneous stochastic differential equation with unknown parameter to be estimated. We prove that the standard maximum likelihood estimate is strongly consistent under very mild conditions. The conditions for strong consistency of the discretized estimator are established as well.     

Existence and regularity of solutions for evolution equations with Riemann–Liouville fractional derivatives

In this paper, we derive the existence and uniqueness of mild solutions for inhomogeneous fractional evolution equations in Banach spaces by means of the method of fractional resolvent. Furthermore, we give the necessary and sufficient conditions for the existence of strong solutions. An example of the fractional diffusion equation is also presented to illustrate our theory.     

A CENTRAL LIMIT THEOREM FOR STRONG NEAR-EPOCH DEPENDENT RANDOM VARIABLES

In this paper, a central limit theorem for strong near-epoch dependent sequences of random variables introduced in [9] is showed. Under the same moments condition, the authors essentially weaken the "size" requirement mentioned in other papers about near epoch dependence.     

线性模型参数M估计的强相合性

本文研究线性模型中回归参数　Ｍ　估计的强相合性，　给出一些较弱的充分条件．　与陈希孺和赵林城的专著［１］中相应的结论比较，　这里给出的条件对矩的要求有较大的实质性改进．