Synthesis and characterization of novel hyperbranched fluorescent polymers that can be precisely used for metal ion detection and quantification

Four novel hyperbranched polymers with 4 or 5 ring-closed rhodamine units in each were achieved through RAFT polymerization followed by modification with rhodamine moieties. The solubility, thermostability, and photophysical properties of the polymers were studied. The polymers showed high selectivity and sensitivity to Fe³⁺ among various metal ions in CH₃CN/H₂O (75/25, v/v) and could signal Fe³⁺ through multichannels: emerging a new absorption around 558 nm, over 30 nm fluorescence redshift and significant fluorescence enhancement (including 33–37 folds in intensity and 8.3–12.8 folds in quantum yield), accompanied by visual and fluorescent color changes. The polymers could be applied in the analysis of Fe³⁺ in real water samples. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48933.     

基于电润湿效应的自变焦补偿光学系统

变焦光学系统是照相机、摄像机等许多光学器件中的关键元件，实现变焦光学系统的微小型化及增大系统的变倍比是一个长期目标。研制了一种三液体自变焦补偿透镜，可在外加电压作用下实现自变焦补偿功能，因此该透镜元件本身可以作为一个简单的变焦光学系统。通过高斯光学理论分析及Zemax模拟仿真验证了该系统的自变焦补偿功能。结果表明，该系统焦距变化范围为378～424 mm，变倍比为1.217，达到了预期目标，对变焦光学系统的研究具有一定的参考价值。     

Magneto-polaron induced intersubband optical transition in a wide band gap II–VI semiconductor quantum dot

Effects of LO-phonon contribution on the electronic and the optical properties are investigated in a Cd_0.8Zn_0.2Se/ZnSe quantum dot in the presence of magnetic field strength. The magneto-polaron induced hydrogenic binding energy as a function of dot radius in the wide band gap quantum dot is calculated. The oscillator strength and the spontaneous lifetime are studied taking into account the spatial confinement, magnetic field strength and the phonon contribution. Numerical calculations are carried out using variational formulism within the single band effective mass approximation. The optical properties are computed with the compact density matrix method. The magneto-polaron induced optical gain as a function of photon energy is observed. The results show that the optical telecommunication wavelength in the fiber optic communications can be achieved using CdSe/ZnSe semiconductors and it can be tuned with the proper applications of external perturbations.     

柴达木盆地三湖坳陷横波勘探中的低幅异常消除技术

近年来,在柴达木盆地三湖坳陷开展了横波地震勘探,但是由于该区低幅度构造发育,横波静校正引起的"低幅"异常与上述低幅度构造相互混杂,难以区分。为此,针对该区横波表层调查难以控制表层横波速度模型的变化、横波近偏移距初至污染严重、横波折射层发育导致高速界面难以确定等问题,首先采用曲线拟合技术预测污染区横波初至时间确保初至完整性,然后采用面波模型与多层折射分层联合约束反演横波表层速度,最后通过基于速度谱分析的层位匹配建模技术确定合理的横波速度界面,形成了横波表层"低幅"异常消除技术,并进行了现场应用及效果评价。研究结果表明:①曲线拟合技术可以弥补近道污染区横波初至空白,保证层析反演模型的完整性;②基于瑞雷波的频散特性反演建模可以为确定该区浅层横波速度提供可靠的资料,提高浅层模型精度;③面波模型与多层折射分层联合约束反演能够更准确的反演该区表层横波速度场,较好地建立横波速度模型,消除横波剖面上"低幅"异常现象。结论认为,所形成的横波地震勘探低幅异常消除技术消除了横波静校正引起的"低幅"异常现象,提高了横波地震资料的成像品质。     

网络化雷达现状及技术发展趋势

随着新的作战对象和作战样式的出现,以及作战环境更加复杂,仅依靠单个雷达节点的能力已经越来越难以满足新的作战需求。文中针对网络化雷达这一新体制雷达开展研究,通过分析国外网络化雷达系统发展现状、趋势及关键技术,总结对我国网络化雷达技术发展的经验启示,为我国网络化雷达系统发展提供技术参考。     

Tailoring Wetting Properties at Extremes States to Obtain Antifogging Functionality

Fog formation decreases light transmission of optically clear materials. A promising approach to address this problem is to control the wetting properties of the material at extremes states, which requires imparting micro and nano morphology features on the surface. However, such features may affect the optical properties of the surface. In this work, superhydrophobic and superhydrophilic surfaces, with different morphology characteristics ranging from nanoscale to hierarchical micro-nanoscale are fabricated and evaluated in order to investigate which wetting extreme and surface morphology is more suitable to preserve the light-transmitting properties and exhibit antifogging functionalities. The performance of the aforementioned surfaces is compared for the first time in two different testing modes: under intense fog flow and no surface cooling, and under no-flow and surface cooling, which enhances dew condensation on the surfaces. It is demonstrated that superhydrophilic surfaces with nanoscale morphology maintain their optical transmittance under fog flow for more than 20 min. This duration is one of the longest reported in the literature revealing the long-term antifogging functionality of the proposed surfaces. Finally, by tailoring the morphology and the surface wetting properties, an optically switching surface (initially “milky” which becomes “clear”) when exposed to humidity is demonstrated.     

基于双态混沌PSO的机载激光通信视轴稳定控制

机载空间激光通信视轴稳定是激光通信链路建立的前提。在视轴稳定平台中应用自抗扰控制方法取得了良好的控制效果,但自抗扰控制需调整参数众多且缺乏规范的调整手段。针对自抗扰控制调参难的问题,本文提出了一种利用双态混沌粒子群算法优化自抗扰控制参数的方法。仿真结果表明,与PSO-PID控制方法相比,该方法具有更快的响应速度,更强的抗干扰能力和更好的鲁棒性。     

双向光收发组件探测器端耦合和封装工艺分析

探测器响应度直接影响双向光收发组件（bi-directional optical sub-assembly，BOSA）的性能，探测器端的耦合和封装在BOSA生产中占据重要地位。为了系统分析BOSA生产中各偏移因素对探测器端耦合的影响，选择探测器电流响应度作为耦合标准进行实验，并通过分析实验结果来得出BOSA探测器端耦合和封装过程中的改进措施。参考BOSA的实际光路，建立光纤-波片-芯片耦合模型，模拟了光束偏移与耦合效率的关系；研究了BOSA耦合和封装工艺中产生的偏移，并分析它们对探测器端耦合效率的影响。随后使用自动耦合设备，对BOSA探测器端进行耦合实验，并分析波片角度偏移、波片与探测器透镜的高度差、探测器透镜水平偏移对耦合效率的影响。实验结果表明：探测器透镜水平偏移对耦合效率的影响最大，波片角度偏移、波片与探测器透镜的高度差对耦合效率的影响较小。研究结果为BOSA探测器端的耦合和封装提供了系统的理论指导，对BOSA的实际生产有一定参考价值。