Repulsive effects in steady axisymmetric fields

In this paper the repulsive effects in the Kerr and Kerr--Newman fields are discussed. The contributions made by all parameters of the fields and test particles to the repulsive effects are also discussed, and the accretive effect on interstellar dust, i.e. the distribution of dust is calculated. The discussion is also carried out on the slow rotation of the Kerr field in which the effect is related to the positions and velocities of the particles and the orientations of their trajectories as well.     

The rotational anisotropies in the ferromagnetism/antiferromagnetism 1/ antiferromagnetism 2 exchange bias structures

The rotational anisotropies in the exchange bias structures of ferromagnetism/antiferromagnetism 1/antiferromagnetism 2 are studied in this paper. Based on the model, in which the antiferromagnetism is treated with an Ising mean field theory and the rotational anisotropy is assumed to be related to the field created by the moment induced on the antiferromagnetic layer next to the ferromagnetic layer, we can explain why in experiments for ferromagnetism (FM)/antiferromagntism 1 (AFM1)/antiferromagnetism 2 (AFM2) systems the thickness-dependent rotational anisotropy value is non-monotonic, i.e. it reaches a minimum for this system at a specific thickness of the first antiferromagnetic layer and exhibits oscillatory behaviour. In addition, we find that the temperature-dependent rotational anisotropy value is in good agreement with the experimental result.     

宽视场大相对孔径星敏感器光学系统设计

介绍了一种用于卫星姿态控制的星敏感器光学系统,该光学系统焦距为51 mm,相对孔径为1/1.1,视场角为21°×21°（圆视场2ω＝30°）,光谱范围为0.5～0.85 μm,采用了复杂化双高斯结构.与普通成像系统不同的是,该系统要求对不同光谱的恒星所采集到的点像能量中心是一致的,且星像点像的弥散圆须控制在一定的范围内.具有倍率色差小、轴上和轴外能量分布比较一致的特点.     

具有高机械强度的掺Er3+∶TeO2-Nb2O5玻璃的光谱性质研究

熔制了掺铒碲铌玻璃样品(100-XTeO2-XNb2O5(X=5,10,15,20 mol%),测试了其密度、折射率、转变温度、析晶温度、维氏机械强度、吸收光谱、荧光光谱、荧光寿命等参量。利用Judd-Ofelt和McCumber理论分别计算了铒离子强度参量Ωt (t=2, 4, 6)和受激发射截面σemi的大小,研究了掺铒碲铌玻璃样品光谱参量对Nb2O5成分的依赖性,并与典型的碲锌钠玻璃（75TeO2-20ZnO-5Na2O）在热学、机械强度、光谱性质和放大品行四个方面进行了比较.     

5 TW/40 fs级台式钛宝石激光系统研究

在TSA-25系统输出35 mJ,800 nm啁啾脉冲的基础上,建立了以钛宝石作为增益介质的二级啁啾脉冲放大(CPA)系统。使用0.6 J和1.6 J,532 nm,10 Hz Nd∶YAG激光抽运,输出脉冲能量达到500 mJ,经压缩脉冲宽度为41 fs,压缩器的能量转换效率为63%,峰值功率可达7.6 TW。通过对放大器系统的钛宝石晶体、抽运密度以及多通结构通道数的选择等实验,有效地提高了能量放大器的萃取效率。其主放大器能量萃取效率达到32%,整个系统占用尺寸不到10 m2。     

KBA显微镜成像系统的成像模拟及X光成像实验的研究

KBA显微镜是一种非轴对称、非共轴的掠入射成像系统。其结构复杂,调节精度要求很高,在实际成像实验操作中难以掌握其成像特性。利用光学设计软件模拟其成像,对系统的调节和成像分析提供有益的参考。利用光学设计软件ZEMAX模拟了KBA显微镜对点源的成像过程,给出了KBA显微镜成像系统的焦深约为1 mm,景深为50 mm左右。并且由模拟可知,掠入射角对成像的影响很大。对像素尺寸约10μm的探测设备,模拟得出KBA成像系统的空间分辨力上限为3μm左右。基于星光Ⅱ装置对周期为20μm的网格靶成像,获得了KBA显微镜较为清晰的X光图像。该项工作为进一步开展掠入射成像系统的研究奠定了基础。     

Resonantly enhanced off-specular X-ray scattering from polymer/polymer interfaces<Superscript>⋆</Superscript>

We have used measurements of the absolute intensity of diffuse X-ray scattering to extract the interfacial tension of a buried polymer/polymer interface. Diffuse scattering was excited by an X-ray standing wave whose phase was adjusted to have a high intensity at the polymer/polymer interface and simultaneously a node at the polymer/air interface. This method permits the capillary-wave-induced roughness of the interface, and hence the interfacial tension, to be measured independently of the polymer/polymer interdiffusion.     

A computational investigation of topological insulator Bi2Se3 film

Topological insulators have a bulk band gap like an ordinary insulator and conducting states on their edge or surface which are formed by spin–orbit coupling and protected by time-reversal symmetry. We report theoretical analyses of the electronic properties of three-dimensional topological insulator Bi₂Se₃ film on different energies. We choose five different energies (–123, –75, 0, 180, 350 meV) around the Dirac cone (–113 meV). When energy is close to the Dirac cone, the properties of wave function match the topological insulator’s hallmark perfectly. When energy is far way from the Dirac cone, the hallmark of topological insulator is broken and the helical states disappear. The electronic properties of helical states are dug out from the calculation results. The spin-momentum locking of the helical states are confirmed. A 3-fold symmetry of the helical states in Brillouin zone is also revealed. The penetration depth of the helical states is two quintuple layers which can be identified from layer projection. The charge contribution on each quintuple layer depends on the energy, and has completely different behavior along K and M direction in Brillouin zone. From orbital projection, we can find that the maximum charge contribution of the helical states is p_z orbit and the charge contribution on p_yand p_x orbits have 2-fold symmetry.