大视场激光探测与告警技术

利用四路红外非制冷焦平面探测器、大视场光学系统、窄带滤光片和信号处理系统,构成了凝视成像激光探测与告警系统。光学系统采用三片式结构的广角镜头来实现大视场;使用先进的非球面光学设计技术,并以FPGA完成探测器响应信号的非均匀校正,以改善像质;通过光学系统的畸变校正,提高激光的探测方向精度;利用激光和背景强度之间的反差,通过激光目标检测算法进行告警。实验表明,该系统能在127视场范围内对波长为1.315靘, 2.7靘, 3.8靘, 10.6靘的4种激光进行告警,探测功率密度范围为0.05 ~50mW/cm2,探测方向精度可达1。     

Magnetron sputtering of TiOxNy films

This article reports on the characterization and preparation of N-doped titanium dioxide (TiO₂) films by reactive magnetron sputtering from Ti(99.5) targets in a mixture of Ar/O₂/N₂ atmosphere on unheated glass substrates. A dual magnetron system supplied by a dc bipolar pulsed power source was used to sputter the TiO_xN_y films. The amount of N in the TiO_xN_y film ranges from 5 to 40 at%. Its structure was measured using X-ray diffraction (XRD), the optical band gap was calculated from Tauc plots and the decrease of the water contact angle α_ir after the film activation by UV irradiation was investigated as a function of at% of N in the TiO_xN_y film. The yellow-coloured TiO_xN_y films with high (≈8 at%) amount of N exhibited a strong decrease of the band gap E_g down to 2.7 eV. A significant decrease of the water contact angle α_ir after UV irradiation has been observed for 2 μm thick transparent nanocrystalline (anatase+rutile) N-doped TiO₂ films containing less than 6 at% of N.     

Co-Se化合物薄膜的电沉积制备与表征

采用电沉积方法在SnO2玻璃基底上制备了Co-Se化合物薄膜.研究了薄膜形成的电化学机理和电沉积工艺对薄膜组成与形貌的影响,并表征了薄膜的结构与光学性质.结果表明:Co2+受预沉积Se的表面诱导还原或直接与H2SeO3的六电子还原反应产物H2Se发生反应形成Co-Se化合物;沉积电位、沉积温度和pH值均显著影响电沉积Co-Se化合物薄膜的形貌与成分;在沉积电位为?0.5V(vs SCE)、沉积温度为50℃和pH值为2.0时可制备出表面致密平整且呈六方晶型结构的富硒CoSe薄膜,其光吸收系数达到1×105 cm?1,直接带隙宽度为(1.53±0.01)eV,接近单结太阳电池光吸收层材料的理论最佳值.     

相位图法研究光子晶体的禁带

给出了一种判断一维光子晶体禁带位置的相位图,利用扩展相位图可方便地描述光子晶体的禁带位置和禁带特征.研究发现,当光子晶体为1/4波片层堆时,光子晶体的禁带最宽;若要进一步展宽禁带,需提高构成周期单元的两种介质的折射率比.对于一般的光子晶体,若周期单元中两种介质的光学厚度不等,则其禁带中心将偏离中心频率的整数倍.此外还研究了禁带中心区的透射率,给出了中心频率附近透射率的一级近似解析解,并由此定性讨论了Fabry-Perot腔的谱线宽度和品质因子.     

基于OFDM的巷道和工作面无线移动通信研究

介绍了适合煤矿井下通信的无线技术“正交频分复用(OFDM)”,通过分析其多载波传输、非可视距性能和抗多径衰耗功能,认为可以在煤矿井下的巷道和工作面环境下高速、可靠地完成数据、话音和视频通信,对OFDM适合于井下通信的工作频带、调制技术和信号产生进行了分析。     

抗渗混凝土膨胀无缝加强带在施工中的应用实例

本文介绍超长结构膨胀无缝加强带施工的基本原理,通过日照市岚山区无害化垃圾处理场工程渗沥液调节池工程实例说明了在超长无缝抗渗混凝土膨胀无缝加强带替代后浇带的技术要点。     

ZnO光子晶体的自组装工艺及带隙特征研究

以Zn（Ac）2和DEG为原料,采用胶体自组装工艺制备了不同胶粒尺寸的ZnO光子晶体,探索了胶体自组装ZnO光子晶体的制备工艺,研究了自组装温度、溶剂、悬浮液浓度、热处理温度等因素对光子晶体排布平整度、周期性和空间紧密度的影响规律,对各种工艺条件下光子晶体的带隙特征进行了研究,试验结果表明,通过自组装工艺条件选择可实现对光子晶体带隙结构的可控性制备。     

Band Structure Engineering of Interfacial Semiconductors Based on Atomically Thin Lead Iodide Crystals

To explore new constituents in two‐dimensional (2D) materials and to combine their best in van der Waals heterostructures is in great demand as being a unique platform to discover new physical phenomena and to design novel functionalities in interface‐based devices. Herein, PbI₂ crystals as thin as a few layers are synthesized, particularly through a facile low‐temperature solution approach with crystals of large size, regular shape, different thicknesses, and high yields. As a prototypical demonstration of band engineering of PbI₂‐based interfacial semiconductors, PbI₂ crystals are assembled with several transition metal dichalcogenide monolayers. The photoluminescence of MoS₂ is enhanced in MoS₂/PbI₂ stacks, while a dramatic photoluminescence quenching of WS₂ and WSe₂ is revealed in WS₂/PbI₂ and WSe₂/PbI₂ stacks. This is attributed to the effective heterojunction formation between PbI₂ and these monolayers; type I band alignment in MoS₂/PbI₂ stacks, where fast‐transferred charge carriers accumulate in MoS₂ with high emission efficiency, results in photoluminescence enhancement, and type II in WS₂/PbI₂ and WSe₂/PbI₂ stacks, with separated electrons and holes suitable for light harvesting, results in photoluminescence quenching. The results demonstrate that MoS₂, WS₂, and WSe₂ monolayers with similar electronic structures show completely distinct light–matter interactions when interfacing with PbI₂, providing unprecedented capabilities to engineer the device performance of 2D heterostructures.     

Ultrabroadband MoS2 Photodetector with Spectral Response from 445 to 2717 nm

Photodetectors with excellent detecting properties over a broad spectral range have advantages for the application in many optoelectronic devices. Introducing imperfections to the atomic lattices in semiconductors is a significant way for tuning the bandgap and achieving broadband response, but the imperfection may renovate their intrinsic properties far from the desire. Here, by controlling the deviation from the perfection of the atomic lattice, ultrabroadband multilayer MoS₂ photodetectors are originally designed and realized with the detection range over 2000 nm from 445 nm (blue) to 2717 nm (mid‐infrared). Associated with the narrow but nonzero bandgap and large photoresponsivity, the optimized deviation from the perfection of MoS₂ samples is theoretically found and experimentally achieved aiming at the ultrabroadband photoresponse. By the photodetection characterization, the responsivity and detectivity of the present photodetectors are investigated in the wavelength range from 445 to 2717 nm with the maximum values of 50.7 mA W^?1 and 1.55 × 10⁹ Jones, respectively, which represent the most broadband MoS₂ photodetectors. Based on the easy manipulation, low cost, large scale, and broadband photoresponse, this present detector has significant potential for the applications in optoelectronics and electronics in the future.