具有捕获的Beddington-DeAngelis功能性反应捕食-食饵模型极限环的存在唯一性

研究具有捕获的Beddington-DeAngelis功能性反应捕食-食饵模型。通过变量变换,将系统转换成一个性质更好的Gause型捕食-食饵模型,在适当条件下得到极限环的存在唯一性结果,补充T.K.Kar的结果。     

双UAVs辅助的混合能量收集MEC系统资源分配策略

针对用户从环境射频源收集能量较少的问题,提出了一种双无人机辅助的混合能量收集边缘计算系统的资源分配策略。通过部署2个具有混合太阳能和射频能量收集功能的无人机,当用户的计算任务较大时,可以将计算任务卸载到搭载边缘服务器的无人机。当用户从环境射频源收集的能量不够用时,另一个无人机飞到用户上方,为其近距离充电。联合考虑无人机和用户的能量消耗,将系统资源分配问题建模成一个混合整数非线性规划问题,在满足用户和无人机计算能力和能量消耗的约束条件下,最小化系统总能耗。通过引入量子行为粒子群优化算法,获得次优解。仿真结果表明,与其他几种方法相比,采用量子行为粒子群优化算法消耗的能量更少。     

具生育脉冲的阶段结构模型的脉冲捕捞策略

以脉冲微分方程理论为基础,研究了一个具阶段结构、生育脉冲和脉冲收获的单种群模型的动力学性质,其中生育脉冲和脉冲收获发生在不同时刻;讨论了模型正周期解的存在性和稳定性;通过利用中心流形定理和分岔理论,得到了filp分岔发生的条件;进一步,给出了相图、周期解和分岔图的数值模拟结果,很好地验证了理论分析结果.     

Improving the mid-infrared energy absorption efficiency by using a dual-band metamaterial absorber

In this paper, a dual-band mid-infrared metamaterial absorber was proposed to improve the energy absorption efficiency. Up to 99% absorption was obtained at 9.03 and 11.83 μm in the simulation, and each absorption band can be tuned by the dielectric spacing layer, i.e., the dielectric constant and its thickness. The dual-band absorption mechanism was analyzed, and the quite well absorption performance at large incident angles was also presented. The results of this study can be applied in the field of thermal absorbing and solar energy harvesting.     

雨水资源在居住建筑节能设计中的利用——贵州省六盘水市世纪雅苑实例研究

水资源是基础性的自然资源和战略性的经济资源.建筑节能设计中的雨水资源的利用则是提高水资源利用效率,改善城市生态环境的重要手段.同样是积跬步,从每一栋建筑、每一个社区、每一个城市、每一个国家做起,追求人类社会的可持续发展,营造良好的人居环境.     

Excited-state dynamics in light-harvesting complex of Rhodobacter sphaeroides

Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results reveal dramatic dynamical evolutions within B800 and B850 absorption bands of antenna complexes LH2. At excitation wavelength around 835 nm,a sharp photobleaching signal was observed which was assigned to the contribution of the two-exciton state,which was further confirmed by the power dependence measurement. Rate equations with eight-level scheme were used to calculate the population evolution in LH2 and the transient dynamics under femtosecond pulse excitation. The research results prove that not only the transition from ground state to one-exciton state but also that from one-exciton state to two-exciton state contribute to the photodynamics of B850.     

济南市雨水加灌地下水技术研究

随着城市化进程的加快,雨水资源浪费与地下水超采这一矛盾日益突出.结合济南市实际情况,对雨水回灌地下水技术如地表入渗、坑塘入渗补给、渗坑入渗补给、水平辐射井补给、加压式人工回灌井做了简单阐述.     

Boosting charge collection efficiency via large-area free-standing Ag/ZnO core-shell nanowire array electrodes

Hybrid nanostructures, comprising of a metal core and a semiconductor shell layer, show great potential for a new generation of low-cost solar cells due to their unique electronic and optical properties. However, experimental results have fallen far short of the ultra-high efficiency(i.e. beyond Shockley-Queisser limit) predicted by theoretical simulations. This limits the commercial application of these materials. Here, a non-transparent organic solar cell with an array of Ag/ZnO nanowires has been experimentally fabricated to increase the internal quantum efficiency(IQE) by a factor of 2.5 compared to a planar counterpart. This result indicates a significant enhancement of charge collection efficiency due to the ultrafast Ag nanowire channels. This hybrid nanostructure can also serve as a perfect back reflector for semi-transparent solar cells, which can result in enhanced light absorption by a factor of 1.8 compared to the reference samples. The enhanced charge collection and light absorption can make these Ag/ZnO nanostructures available for the application of modern optoelectronic devices.     

一类基于比率的且有收获率和时滞的捕食系统在时间尺度上的周期解

研究一类基于比率且具有收获和时滞的两种群捕食者—食饵周期系统,利用重合度理论中的延拓定理建立了这类系统在时间尺度上正周期解存在的一个充分性判据,推广了已知的相关结论.     

压力流屋面雨水排水管系水力模型研究

根据压力流屋面雨水排水管系的水流特点及其水头损失的计算公式,确定了采用有限元法分析其水力平衡计算的数学模型,将各个计算管段的单元矩阵方程集合为雨水排水管系的整体矩阵方程,引入节点水压边界条件并求解管系整体矩阵方程对称正定线性方程组,从而得出各项水力要素,给出了计算程序框图,并编写了通用电算程序.经实例计算表明,此模型能够快捷准确地进行压力流屋面雨水排水管系的水力平衡计算.