小型风光互补发电演示装置

研制了适用于大学物理演示实验教学的小型风光互补发电演示装置,该装置由叶片、风力发电机、光伏太阳能电池板、控制器、蓄电池、逆变器、负载等几部分组成.整个系统以光电互补控制器为核心,经由风力发电机与光伏太阳能电池板将风能和太阳光能转变为电能,并将其储存于蓄电池中供负载使用.该装置展示了风力发电系统的组成,演示了风力发电原理和相关空气动力学原理.     

基于MPPT控制的新型仿生学太阳树灯设计

根据仿生学原理,通过仿造树的结构制作一个树的支架,将太阳能电池板以45°的倾角放在树枝架上,然后通过WS-ALMPPT15控制器和12V/20Ah的铅酸蓄电池、负载(包括直流负载、交流负载)相连。实验测试表明:在产生电力方面,新型树灯在一天内的平均输出功率将比普通的平板太阳能电池板的输出功率输出高出27.3%;此外,新型树灯的输出电压、电流、功率基本上趋于一致,这些都高效地节约了电能。     

3种太阳能动力磁悬浮演示仪器

设计制作了以太阳能为动力的太阳能电磁动力旋转仪器、太阳能永磁悬浮旋转仪器和悬挂式太阳能叶片旋转仪器.演示仪使用了不同的悬浮原理,使其转轴部分与仪器其他部分不存在机械接触,同时能够保持自身稳定平衡.演示内容涵盖了太阳能电池板原理、各种形状磁场分布、通电线圈受力分析和悬浮力分析.     

激光通信演示实验仪的设计与实现

为了直观的演示激光通信技术的原理,设计制造了一款简易的激光通信演示实验仪,能够将输入信号调制为激光信号进行无线传输,接收端通过太阳能电池板进行光电转换,再经滤波、解调放大,最终还原输入信号的电路,该仪器性能稳定、操作方便、成本低廉,演示实验效果良好。     

太阳能光伏光热扁管式蒸发器性能分析

根据太阳能光伏光热蒸发器与制冷系统之间的能量平衡,建立了光伏光热扁管式蒸发器性能的数理模型。该模型考虑了光伏光热扁管式蒸发器的传热系数变化,并分析了太阳辐射强度、环境温度、制冷循环的蒸发温度对光伏光热扁管式蒸发器的电池板温度、电池板光电转换效率、电池板发电功率以及光伏光热蒸发器散热量的影响。     

太阳能驱动全天候监控系统的实验设计

研发了一套太阳能全天候监控系统设计性实验。该实验通过对太阳能电池板基本物理性能的测定,了解其工作原理,然后选择合适的控制器件与负载,设计电路,最后形成一套由太阳能电池板提供能量,实现全天候监控的应用系统。该实验不仅能够作为设计性实验用于大学物理实验,而且可以应用于许多工程领域。     

基于热电制冷效应的光伏热水系统效能分析

基于热电制冷效应的光伏热水系统,主要由太阳能光伏电池板、太阳能数字控制器、温度监控及开关转换控制器、热电制冷模块组成。文中通过采用国产应用较为成熟的三元碲化铋-碲化锑固溶体合金作为材料,来设计热电制冷模块并计算出系统的制冷系数和供热系数,得出系统供热功率是传统电加热功率的1.98倍,与传统热泵一样,系统供热系数可达3.03,都具有较高的性价比。最后通过CFD软件进行简单模拟校核,结果表明:添加热电制冷模块后,温度明显下降,光电转化效率提高8%左右,运行更加稳定,为热电制冷技术在太阳能热水系统后续研究提供必要的理论依据。     

太阳能电池板负载特性的实验研究

通过对太阳能电池板内阻随光照强度变化和电池板输出功率随负载电阻变化的研究,分析了光照强度和负载电阻对输出功率的影响机制,得到电池板最佳输出功率的负载值.     

独立光伏系统充放电控制器的研究与设计

设计了一种基于STM32微处理器和Buck电路的光伏控制器,并提出了一种改进型变步长扰动观察法来提高光伏系统的最大功率点跟踪(MPPT)性能,同时实现了蓄电池的合理充放电及过放保护;样机实验结果表明:该光伏控制器能在0.01 s的时间内克服扰动,并且MPPT的效率达到了99.94%,该光伏控制器具有快速的动态响应和良好的稳态性能,并能很好地监测蓄电池的状态,减少电池损耗,延长蓄电池寿命。     

一种用于基站的柴油发电机组控制器的研究

针对山区、偏远乡村等地的通信基站用柴油发电机设计一款专用控制器;基站使用柴油发电机供蓄电池充电作为电源,控制器实现蓄电池电量监控,显示以及控制柴油发电机自动停开机和对蓄电池充电的功能;控制器以具有Cortex-M4内核的STM32F407芯片为核心,通过μC/OS-II实时操作系统和PID算法对发电机和蓄电池充电进行实时控制;实验表明,控制器能够实现发动机的自动控制,在为蓄电池充电过程中恒压波动小于±0.1 V,恒流波动小于±0.2 A,实现蓄电池快速稳定充电,满足基站的供电需求。     

Anisotropic third-moment estimates of the energy cascade in solar wind turbulence using multispacecraft data

The first direct determination of the inertial range energy cascade rate, using an anisotropic form of Yaglom's law for magnetohydrodynamic turbulence, is obtained in the solar wind with multispacecraft measurements. The two-point mixed third-order structure functions of Els?sser fluctuations are integrated over a sphere in magnetic field-aligned coordinates, and the result is consistent with a linear scaling. Therefore, volume integrated heating and cascade rates are obtained that, unlike previous studies, make only limited assumptions about the underlying spectral geometry of solar wind turbulence. These results confirm the turbulent nature of magnetic and velocity field fluctuations in the low frequency limit, and could supply the energy necessary to account for the nonadiabatic heating of the solar wind.     

On Yaglom’s Law for the Interplanetary Proton Density and Temperature Fluctuations in Solar Wind Turbulence

In the past decades, there has been an increasing literature on the presence of an inertial energy cascade in interplanetary space plasma, being interpreted as the signature of Magnetohydrodynamic turbulence (MHD) for both fields and passive scalars. Here, we investigate the passive scalar nature of the solar wind proton density and temperature by looking for scaling features in the mixed-scalar third-order structure functions using measurements on-board the Ulysses spacecraft during two different periods, i.e., an equatorial slow solar wind and a high-latitude fast solar wind, respectively. We find a linear scaling of the mixed third-order structure function as predicted by Yaglom’s law for passive scalars in the case of slow solar wind, while the results for fast solar wind suggest that the mixed fourth-order structure function displays a linear scaling. A simple empirical explanation of the observed difference is proposed and discussed.     

太阳能强化自然通风理论分析及其在生态建筑中的应用

生态建筑作为建筑节能的一个全新设计理念,旨在最大限度地利用风能、太阳能等自然能源,削减不可再生能源的耗费。将太阳能烟囱、Trombe墙以及太阳能空气集热器等构件与生态建筑一体化设计安装能够取得较好的效果。本文以太阳能烟囱为例对太阳能强化自然通风的原理进行了理论分析与模拟计算。同时,介绍了较为典型的三种太阳能强化自然通风的复合能量系统。     

The role of O+ ions in channeling solar wind energy tothe ionosphere

In space weather prediction, the transport of solar wind energy through the magnetosphere is a major aspect. For the transport of energy from the magnetosphere to the ionosphere, magnetic field-aligned (Birkeland) currents are a very important agent. The authors discuss the role of O⁺ ions for driving field-aligned currents of spatially alternating polarity that may explain multiple auroral arcs. It is known from earlier work that nonadiabatic motion of O⁺ ions in the magnetotail plasma can lead to the formation of density striations that are stationary in the GSM frame. As the magnetospheric plasma drifts through these density striations, magnetic field-aligned currents of alternating signs are forced to flow in and out of the oxygen-rich region to maintain quasineutrality. This generates Alfven waves that propagate in the drifting plasma but can form stationary structures in the GSM frame. As the currents close in the ionosphere, the equatorial plasma constitutes a generator from which spatially alternating magnetic field-aligned currents carry energy to the ionospheric load. The wavelength of the density striations, mapped to the ionosphere, is compatible with the spacing of stable auroral arcs, and the power supplied by the equatorial generator region is estimated to be compatible with what is needed to drive auroral arcs. Thus, the consequences of nonadiabatic motion of O⁺ ions may explain how part of the energy extracted from the solar wind is channelled into multiple auroral arcs     

太阳能制氢腔式吸热器混合对流的数值模拟研究

混合对流热损失是影响太阳能与生物质超临界水气化耦合制氢腔式吸热器热效率的关键因素之一。本文以动力工程多相流实验室建成的生物质超临界水与太阳能聚集供热耦合制氢腔式吸热器为研究对象,对腔式吸热器混合对流换热进行了数值模拟研究。通过使用RNGkε湍流模型,研究了制氢吸热器在外界风吹掠环境下的混合对流热损失,获得了腔式吸热器在不同风速、风向吹掠下的混合对流换热准则Nusselt数。模拟结果表明,侧向风与侧迎向风对腔内对流热损失影响最大,当风速超过某一数值(Richardson数>1),外界风诱发的强制对流会在对流热损失中占主导作用,且随着风速增加,混合对流热损失随Re提高而增大。     

Self-similar signature of the active solar corona within the inertial range of solar-wind turbulence

We quantify the scaling of magnetic energy density in the inertial range of solar-wind turbulence seen in situ at 1 AU with respect to solar activity. At solar maximum, when the coronal magnetic field is dynamic and topologically complex, we find self-similar scaling in the solar wind, whereas at solar minimum, when the coronal fields are more ordered, we find multifractality. This quantifies the solar-wind signature that is of direct coronal origin and distinguishes it from that of local MHD turbulence, with quantitative implications for coronal heating of the solar wind.     

Dye-sensitized solar cells concocted with dyes extracted from fresh and dried leaves of Henna using different solvents

Optical and Quantum Electronics - Nowadays, world is moving from conventional energy sources to non-conventional energy sources like solar energy, wind power, hydropower and those energy sources...     

The solar wind interaction with the Earth's magnetosphere: atutorial

The size of the terrestrial magnetosphere is determined by the balance between the solar wind dynamic pressure and the pressure exerted by the magnetosphere, principally that of its magnetic field. The shape of the magnetosphere is additionally influenced by the drag of the solar wind, or tangential stress, on the magnetosphere. This drag is predominantly caused by the mechanism known as reconnection in which the magnetic field of the solar wind links with the magnetic field of the magnetosphere. The factors that control the rate of reconnection of the two fields are not understood completely, but a southward direction of the interplanetary field is critical to enabling reconnection with the dayside low-latitude magnetosphere, resulting in magnetic flux transfer to the magnetotail. Numerical simulations suggest that the conductivity of the ionosphere controls the rate of reconnection, but this has not been verified observationally. Although solar wind properties ultimately control the interaction, the properties of the plasma that make direct contact with the magnetosphere are different than those of the solar wind, having been altered by a standing bow shock wave. This standing shock is necessitated by the fact that the flow velocity of the solar wind far exceeds the velocity of the compressional wave that diverts the solar wind around the Earth. The upper atmosphere is the final recipient of all the energy and momentum that enters the magnetosphere. Coupling takes place along the magnetic field Lines principally in the polar and auroral region via current systems that close across the magnetic field both at low and high altitudes and flow parallel to the magnetic field between high and low altitudes     

Observation of inertial energy cascade in interplanetary space plasma

Direct evidence for the presence of an inertial energy cascade, the most characteristic signature of hydromagnetic turbulence (MHD), is observed in the solar wind by the Ulysses spacecraft. After a brief rederivation of the equivalent of Yaglom's law for MHD turbulence, a linear relation is indeed observed for the scaling of mixed third-order structure functions involving Els?sser variables. This experimental result firmly establishes the turbulent character of low-frequency velocity and magnetic field fluctuations in the solar wind plasma.