高频泵波加热电离层的数值模拟

基于高频泵波扰动电离层的欧姆加热理论,建立数值模型模拟加热过程中电子温度、电子密度和离子密度随时间的演化及泵波频率、发射功率对加热效果的影响.结果表明,地面以1.5MW的功率发射一个13MHz的电波,可以引起电子温度升高80%、电子密度升高16%的显著变化.电子温度和电子密度的变化分别在加热开始后几十秒和几分钟内达到饱和.泵波频率和发射功率大小显著影响最终的加热效果,但数值结果并没有体现它们之间具有线性关系.和EISCAT雷达1985年2月26日对一次加热实验观测结果(它的发射功率和本文选定的1.5MW一致)的比较表明,在180km以下区域,该文模型和上述实验观测结果具有很好的一致性;更高高度上模拟结果和实验结果的偏差是由于模拟过程中没有考虑F层异常吸收的作用.     

适用于圆筒形放电区的四镜半外腔的失调分析

基于矩阵分析方法,对提出的圆筒形增益区的四镜半外腔的腔镜失调特性进行了分析,并用数值计算例子加以说明,给此类新型激光器的实际工作,如加工腔元件、选择腔参数、安装调试等提供了参考.     

非线性在影视剪辑中的内涵及发展趋势

一般认为,非线性剪辑是基于计算机数字技术、打破磁带线性顺序存储素材局限的一种剪辑方式,近年来非线性剪辑已经占据影视后期制作的大半江山,探讨这种剪辑方式的发展趋势以及在此基础上衍生出的影视剪辑心理层面和叙事结构层面的非线性倾向.     

CO2激光器失调运行时的近场分析

针对三维轴对称折叠组合腔CO2激光器在失调运行时的近场特性进行分析.对非相干和相干并和的输出进行比较,为失调的CO2激光器的分析和调整提供了一种有效手段.     

基于G／comms平台的广电网络一体化设计模式的研究与实现

本文简要介绍了G／Comms软件平台和东方有线网络资源管理系统的建设情况。介绍了东方有线基于G／COMMS平台的网络一体化设计模式及其主要功能模块,并深入分析和比较了传统有线网络设计和一体化设计两种模式。希望能够为广电网络设计提供一些有益的参考。     

CIGS太阳能电池缓冲层ZnS薄膜的制备与表征

以硫酸锌、(NH4)2S2O3混合溶液为前驱体溶液,加入少量的柠檬酸钠和丙三醇为络合剂和分散剂,采用化学浴沉积法在玻璃衬底上成功制备了表面均匀的ZnS薄膜。研究了沉积时间和退火时间对ZnS薄膜质量的影响,并运用扫描电镜(SEM)、X射线衍射(XRD)、紫外-可见光光度计对薄膜进行分析和表征。结果表明:在沉积时间为90m in,退火温度为200℃时制得的薄膜性能较好,晶体结构为纤锌矿结构。制备的薄膜透过率(λ>400nm)约为80%,薄膜的禁带宽度约为3.75eV。通过添加少量的分散剂丙三醇可以改善ZnS薄膜质量。退火温度为300℃,薄膜表面形貌均匀致密。     

注重统计思想的现代工科概率统计教学方法

指出了工科概率统计教学中长期存在而又被忽视的一个问题,即学生的统计计算能力有余而对于统计思想、统计方法的理解与使用不足.并尝试着提出了注重统计思想的现代统计教学方法.     

Resonantly driven exciton Rabi oscillation in single quantum dots emitting at 1300 nm

We report on the resonance fluorescence(RF) from single In As quantum dots(QDs) emitting at the telecom band of 1300 nm. The InAs/GaAs QDs are embedded in a planar optical microcavity and the RF is measured by an orthogonal excitation-detection geometry for deeply suppressing the residual laser scattering. An ultra-weak He–Ne laser is necessary to be used as a gate laser for obtaining RF. Rabi oscillation with more than one period is observed through the picosecond(ps) pulsed laser excitation. The resonant control of exciton opens up new possibilities for realizing the on-demand single photon emission and quantum manipulation of solid-state qubits at telecom band.     

Spectral dynamical behavior in two-section,quantum well,mode-locked laser at 1.064 μm

In this study, two-section mode-locked semiconductor lasers with different numbers of quantum wells and different types of waveguide structures are made. Their ultrashort pulse features are presented. The spectral dynamical behaviors in these lasers are studied in detail. In the simulation part, a two-band compressive-strained quantum well(QW) model is used to study thermally induced band-edge detuning in the amplifier and saturable absorber(SA). A sudden blue shift in laser spectrum is expected by calculating the peak of the net gain. In the experiment part, the sudden blue shift in the emission spectrum is observed in triple QW samples under certain operating conditions but remains absent in single QW samples.Experimental results reveal that blue shift phenomenon is connected with the difference between currents in two sections.Additionally, a threshold current ratio for blue-shift is also demonstrated.     

Electrically Driven InAs Quantum-Dot Single-Photon Sources

Electrically driven single photon source based on single InAs quantum dot （QDs） is demonstrated. The device contains InAs QDs within a planar cavity formed between a bottom AlCaAs/CaAs distributed Bragg reflector （DBR） and a surface CaAs-air interface. The device is characterized by I-V curve and electroluminescence, and a single sharp exciton emission line at 966nm is observed. Hanbury Brown and Twiss （HBT） correlation measurements demonstrate single photon emission with suppression of multiphoton emission to below 45% at 80 K