利用山路引理、Hölder不等式、嵌入不等式和估值等,研究了一类含临界非局部项且位势在无穷远处消失的Schrödinger-Poisson系统的非平凡解的存在性.首先利用嵌入不等式证明了泛函具有紧性,然后利用截断函数对泛函进行了估值,最后用变分方法证明了该系统至少有一个非平凡解.所得结果丰富了椭圆型方程解的相关理论.
讨论了一类切换正时滞系统的稳定性和镇定性.首先,通过构造多元共正李雅普诺夫泛函,得到了切换正时滞系统在可容许边依赖平均驻留时间(AED-ADT)切换信号下的有限时间稳定的充分条件;其次,设计了一类状态反馈控制器,并给出了闭环系统在AED-ADT切换信号下具有有限时间稳定的判据.最后,利用两个算例验证了所得结果的正确性.
研究了一类Bézier型Szász-Mirakjan-Kantorovich算子.首先,给出了该类算子的一阶、二阶中心矩;然后,利用Lipschitz型不等式得到了该类算子的范数不等式,并利用二阶连续模和K泛函讨论了该算子的逼近性质;最后,给出了该类算子对Lipschitz函数类的逼近定理.
In this paper, a cortex-basal ganglia model about Parkinson’s disease with two time delays is studied, and the critical conditions for Hopf bifurcation are derived. The results show that time delays can change the state of basal ganglia. The basal ganglia is stable when the delays are small. However, when the time delay is greater than the corresponding bifurcation critical point, different types of oscillations occur in the basal ganglia. The larger the time delays, the more active the neuronal clusters in the basal ganglia. Furthermore, the bidirectional Hopf bifurcation is found by studying the connection weights between different neural nuclei. Finally, the influence of connection weight and time delay which are related to the internal segment of the globus pallidus on its oscillation is discussed. Research shows that reducing the connection weight and the corresponding time delay in excitatory neuronal clusters, or increasing the connection weight and decreasing the corresponding time delay in inhibitory neuronal clusters, can improve the oscillation of Parkinson’s disease.
由于Mn离子的发射光谱可与植物光敏色素的吸收光谱重叠,因此其可被应用于植物照明领域中.但由于Mn离子的发射光强度较低,使得其在实际应用中受到很大限制;因此,加强掺杂Mn离子材料的吸收能力对提高其在植物照明领域中的应用具有重要意义.为此,对近年来掺杂Mn4+离子和Mn2+离子荧光粉的发光特性的相关文献进行了综述,以期为研究具有优良特性的新型植物照明用荧光粉提供参考.
