Escape and Stand of the Pluto Atmosphere

Molar mass μ_min of the lightest gas, which will exist ``forever' in the atmosphere at the planet surface, can be evaluated by Jeans rule. The μ_min of Pluto is 17.3 g•mol^-1. It is evident that both N₂ and CO can be major atmospheric composition at the Pluto surface, and will exist “forever”. CH₄ can only be escaping slowly from Pluto atmosphere, and still holds quite a proportion in current Pluto atmosphere. However, it will not escape from Titan (or Jupiter, Saturn) atmosphere largely, and will exist “forever”. Given the quantity level of partial pressure of CH₄ in Pluto and Titan (or Jupiter, Saturn) original atmosphere is the same, it will be clear that the current partial pressure of CH₄ in Pluto surface atmosphere is 10^-3 Pa.     

利用位力定理估算球状星团的质量

位力定理用于描述稳定状态下N体自引力系统的动能与引力势能之间的联系,在天体物理研究中有广泛应用.球状星团是银河系内最大的恒星系统,经过长期的动力学演化已达到稳定状态.本文利用4个球状星团NGC 1851,NGC 1904,NGC7099和NGC 5964的高精度视向速度数据,结合位力定理估算了星团的动力学质量.我们得到的动力学质量分别是1.99×10~(35)kg,1.08×10~(35)kg,0.89×10~(35)kg和9.71×10~(35)kg,或表示成太阳质量为0.99×10~5M_⊙,0.54×10~5M_⊙,0.44×10~5M_⊙和4.88×10~5M_⊙.     

Synthesis and Characterization of ZnO Nanoflowers Grown on AlN Films by Solution Deposition

ZnO nanoflowers are synthesized on AlN films by solution method. The synthesized nanoflowers are composed of nanorods, which are pyramidal and grow from a central point, thus forming structures that are flower-shaped as a whole. The nanoflowers have two typical morphologies： plate-like and bush-like. The XRD spectrum corresponds to the side planes of the ZnO nanorods made up of the nanoflowers. The micro-Raman spectrum of the ZnO nanoflowers exhibits the E2 （high） mode and the second order multiple-phonon mode. The photoluminescence spectrum of the ZnO nanoflowers exhibits ultraviolet emission centred at 375nm and a broad green emission centred at 526 nm.     

高吸收ZnSe多晶无镜光学双稳的实验观测

本文对具高吸收的ZnSe多晶材料的增加吸收型光学双稳性进行了实验观测,发现在介质的吸收远高于过去提出的理论判据时,仍能获得双稳输出,并测定了阈值开关功率与光斑尺寸及样品厚度的关系.采用分层模型分析实验结果,定性地解释了实验现象.     

二甲醚/动力多联产系统初步研究

本文针对两步法二甲醚/动力多联产系统进行了研究。通过对两步法二甲醚生产和动力两个系统的分析整合,使用ASPEN对流程进行了模拟计算,考察了两步法DME和IGCC联产系统的特性。发现两步法DME-IGCC联产与两步法:DME和IGCC分产相比,折合热转功效率提高了5.66个百分点,折合合成能耗下降了26.05％,相对节能率为8.46％。     

Topological Structure of Vortex Solution in Jackiw-Pi Model

By using φ-mapping method, we discuss the topological structure of the self-duality solution in Jackiw-Pi model in terms of gauge potential decomposition. We set up relationship between Chern-Simons vortex solution and topological number, which is determined by Hopf index and Brouwer degree. We also give the quantization of flux in this case. Then, we study the angular momentum of the vortex, which can be expressed in terms of the flux.     

光纤光栅对FBG-ECL静态特性的影响

光纤光栅外腔半导体激光器(FBG-ECL)在未来光通信系统占有着越来越重要的地位。根据FBG-ECL的等效腔模型,讨论了光纤光栅反射率、带宽对FBG-ECL的输出功率,阈值特性、边模抑制比等静态特性的影响。指出了存在最佳光纤光栅峰值反射率,不仅使得FBG-ECL具有更高的输出功率,而且可以获得极好的边模抑制比。最后根据实测在不同反射率下外腔激光器的激射光谱,发现理论分析结果和实验数据是吻合的。     

1.55μm相干激光测风雷达平衡式探测接收实验

研究了用于相干激光测风雷达信号接收的平衡式探测接收技术.推导出了平衡式相干探测过程的数学模型和信噪比表达式,并通过仿真软件对该模型进行了模拟仿真.在同等输入条件下,当平衡式相干探测系统的最佳分束比范围在[0.293,0.707]时,其信噪比比普通相干探测的信噪比高.此外,平衡式探测接收还具有判断风向的功能,最后通过实验验证了仿真结果.     

A Protocol for Bidirectional Quantum Secure Communication Based on Genuine Four-Particle Entangled States

By swapping the entanglement of genuine four-particle entangled states, we propose a bidirectional quantum secure communication protocol. The biggest merit of this protocol is that the information leakage does not exist. In addition, the ideas of the ＂two-step＂ transmission and the block transmission are employed in this protocol. In order to analyze the security of the second sequence transmission, decoy states are used.