硅光电池实验设计

采用开放式的实验平台设计了硅光电池系列实验,测量了硅光电池在全暗和光照下的伏安特性,开路电压、短路电流和输出电压与光照强度的关系,以及短路电流和开路电压与温度的依赖关系.实验内容包含电学和光度学知识,学生可以掌握硅光电池的工作原理和基本特性.     

基于LabVIEW的激光功率数据采集系统

针对全固体激光器的长期功率稳定性检测问题,设计并实现了基于LabVIEW图形设计语言的激光功率数据采集系统。采用光电池制作的激光功率计来实现光功率到电学参量的转换,通过合理的选取激光功率计的滤光片、衰减片和毛玻璃,保证光电池工作在非饱和的线性区。使用STC89C52RC单片机对采集到的信号进行处理,计算机与单片机采用串口通讯,数据采集界面程序采用LabVIEW编写,最终实现了激光功率长期稳定性监测系统的设计、调试与制作。     

基于KNX的地下停车场智能监控及车位引导系统

针对目前地下停车场的自动化监控和管理方式单一,缺乏智能化的停车位引导以及停车场内照明、通风、泵站设施管理方式落后等问题,提出一种基于KNX的地下停车场智能监控及车位引导系统;通过将各个KNX节点设备挂载到KNX总线上,构建KNX系统,通过挂接在KNX总线上的智能终端实现对整个地下停车场的监控与管理,即实现对停车场照明、通风设备的管理和监控,以及车辆检测、车位检测以及车辆进入车位的智能引导功能;经实践验证,系统运行稳定可靠,实时性好,抗干扰能力强。     

微米级圆孔孔径的光电检测

工业生产中经常需要测量微米级圆孔孔径的大小.基于圆孔的夫琅禾费衍射原理,激光经过圆孔衍射在接收屏上形成圆环型条纹分布,孔径改变时,艾里斑区域的激光能量密度随之改变,利用光电池作为光电探测器,只接收大部分艾里斑中心光强信号而屏蔽其他高级次的衍射亮环,光电池输出的电压值反应了孔径直径大小.单片机作为控制系统,采用双光路的光电检测方法,搭建了检测系统.利用已知孔径的圆孔标定系统后,获得电压信号与孔径大小的对应关系,通过拟合可以得到检测系统的函数关系式.实验表明,可以实现50~300μm孔径大小的检测.     

基于LabVIEW研究硅光电池特性

利用LabVIEW配合Nextkit数据采集卡,通过计算机实时测量,研究了硅光电池的照度特性和输出特性.实验结果显示,用虚拟仪器平台进行硅光电池特性实验,有助于学生了解虚拟实验及实时测量现代测量技术.     

基于SPARK科学学习系统的硅光电池实验研究

SPARK科学学习系统为移动便携式数据采集和分析的实验系统,适合课内及课外不同环境下学生开展实验探究与科学研究,并可通过网络实时共享实验数据,开展科学合作与在线指导,有效激发学生的科研兴趣,培养创新能力。利用该系统进行硅光电池特性研究,测定硅光电池在全暗和光照下的伏安特性、开路电压及短路电流与光照强度的关系,结果表明,在物理实验中应用该系统,具有测量便捷,数据处理手段丰富,结果清晰的优势。     

利用双光栅的多普勒频移测速度

衍射光的多普勒频移是与光栅运动速度有关的量.激光束依次通过动光栅、静光栅衍射,然后使1对光频不同、彼此平行又能部分重叠的衍射光束通过硅光电池进行光电转换,得到的信号电流的频率等于多普勒频移.信号电流经I/V转换、f/V转换和A/D转换后,由单片机测出电压,由此就可以确定动光栅的运动速度.最后对利用双光栅的多普勒频移测气垫导轨上滑块的速度进行分析和讨论.     

激光器用高频调制射频激励源的实时监测系统

介绍了基于C8051F023单片机的高速数据采集系统的设计,在LABVIEW环境下实现数据处理和分析系统的设计。两者通过串口结合能实现对射频激励源入射和反射信号的电压值、功率值、频率、占空比等参数实时监测。     

太阳能电池特性的自动测量

利用C8051F020单片机实现了对光电池的开路电压、短路电流、串联内阻、最佳负载、最佳输出功率等重要参数的自动测量和数据处理,并在液晶屏上自动显示相应的曲线.结合实际应用的情况,还测量了串联光电池和并联光电池的参数.     

硅光电池的特性研究

基于GGDC-B型硅光电池综合实验仪,研究硅光电池的基本特性。通过实验得出随着光照度的增加,硅光电池的输出电压与电流逐渐增大。在一定光照度范围内,随着负载阻值的逐渐增大,输出电流与光照度呈线性关系。负载阻值越小,输出电流与光照度呈线性关系的范围越大。在可见光范围内,硅光电池的敏感程度随波长的增大而增大。     

Point defects on graphene on metals

Understanding the coupling of graphene with its local environment is critical to be able to integrate it in tomorrow's electronic devices. Here we show how the presence of a metallic substrate affects the properties of an atomically tailored graphene layer. We have deliberately introduced single carbon vacancies on a graphene monolayer grown on a Pt(111) surface and investigated its impact in the electronic, structural, and magnetic properties of the graphene layer. Our low temperature scanning tunneling microscopy studies, complemented by density functional theory, show the existence of a broad electronic resonance above the Fermi energy associated with the vacancies. Vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in freestanding graphene layers.     

基于Matlab分析负荷对多联机IPLV的影响

多联机有其特殊的优点,但是不同部分负荷的组合对IPLV的影响仍需进一步研究。文中建立IPLV与部分负荷的相关公式,运用MATLAB软件分析不同卸载级负荷与IPLV的关系,从而确定不同部分负荷的最优组合。     

Note on duality on polarized symplectic manifolds

In this note we use some of the results of [3] to derive a general duality theorem for the cohomologies of foliated structures on a manifold. The result is applied to the special case of a symplectic manifold M on which the foliation is given by a complex polarization F in the sense of geometric quantization. We obtain, for example, a rigorous proof of the fact that for a smooth function ƒ on M whose Hamiltonian vector field leaves F invariant, the spectrum of the corresponding prequantization operator v(ƒ) coincides with the spectrum of its transpose, under the above duality. This latter result was obtained by Simms in [12] under certain hypotheses. Proofs of the validity of those hypotheses are now available in the literature; cf. [3] and [7].     

Space-charge effects on multipactor on a dielectric

Analyzes the effects of space charge shielding on the steady state of a multipactor discharge on a dielectric. Analytic methods are used to obtain an exact function for the potential in the discharge, assuming a Maxwellian distribution of emitted electrons. An equation for the amount of power deposited on the dielectric by the multipactoring electrons, for a given saturation level, is given. A simple method for obtaining the saturation level, for a given material, is obtained     

Remarks on KdV-type flows on star-shaped curves

We study the relation between the centro-affine geometry of star-shaped planar curves and the projective geometry of parametrized maps into RP¹. We show that projectivization induces a map between differential invariants and a bi-Poisson map between Hamiltonian structures. We also show that a Hamiltonian evolution equation for closed star-shaped planar curves, discovered by Pinkall, has the Schwarzian KdV equation as its projectivization. (For both flows, the curvature evolves by the KdV equation.) Using algebro-geometric methods and the relation of group-based moving frames to AKNS-type representations, we construct examples of closed solutions of Pinkall’s flow associated with periodic finite-gap KdV potentials.