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一种微通道板及在微通道板内壁制备Ni掺杂AlO高阻薄膜的方法
No full text本发明涉及一种微通道板及在微通道板内壁制备Ni掺杂Al2O3高阻薄膜的方法，高阻薄膜是通过原子层沉积方法在微通道板内壁进行不同组分材料沉积来获得Ni掺杂Al2O3的高阻薄膜的，沉积时，在一个大循环中，通过控制Al2O3沉积次数与Ni沉积次数，以控制Ni掺杂比例，从而可在106‑1010Ω·cm范围内精确调控薄膜的电阻率；通过控制大循环的循环次数控制薄膜的厚度。所制备的薄膜在高温工作环境下或高温退火后，电阻率基本保持恒定，解决了现有微通道板表面薄膜在高温条件下电阻率变化大导致微通道板性能不稳定的技术问题。</p
High-resolution reconstruction of shortwave infrared polarimetric images using the intensity information of visible images
No full textShortwave infrared (SWIR) polarimetric imaging has been found very effective in various applications. However, the low resolution of the SWIR camera severely limits the capacity of this technique. Image reconstruction methods have been developed to improve the spatial resolution, but these methods typically do not consider the polarized information that the images may contain. In this paper, we propose a high-resolution reconstruction method for SWIR images based on the spatial information of visible images without losing polarized information in the SWIR image. Experimental results demonstrate that this method is feasible to reconstruct high-resolution polarized SWIR images. We have also demonstrated its potential application in image fusion. (C) 2019 Optical Society of America</p
Spatiotemporal interest point detector exploiting appearance and motion-variation information
No full textAs a local invariant feature of videos, the spatiotemporal interest point (STIP) has been widely used in computer vision and pattern recognition. However, existing STIP detectors are generally extended from detection algorithms constructed for local invariant features of two-dimensional images, which does not explicitly exploit the motion information inherent in the temporal domain of videos, thus weakening the performance of existing STIP detectors in a video context. To remedy this, we aim to develop an STIP detector that uniformly captures appearance and motion information for video, thus yielding substantial performance improvement. Specifically, under the framework of geometric algebra, we first develop a spatiotemporal unified model of appearance and motion-variation information (UMAMV), and then a UMAMV-based scale space of the spatiotemporal domain is proposed to synthetically analyze appearance information and motion information in a video. Based on this model, we propose an STIP feature of UMAMV-SIFT that embraces both appearance and motion variation information of the videos. Three datasets with different sizes are utilized to evaluate the proposed model and the STIP detector. We present experimental results to show that the UMAMV-SIFT achieves state-of-the-art performance and is particularly effective when dataset is small. (C) 2019 SPIE and IS&T</p
A Filamentary Plasma Jet Generated by Argon Dielectric-Barrier Discharge in Ambient Air
No full textA filamentary plasma jet was produced by a cylindrical dielectric-barrier discharge ( DBD) equipped with a thin quartz tube. This plasma jet consists of many filaments, and the filaments bifurcate into thinner branches close to the ground electrode. Only a single filament is produced in each current pulse, and this filament is distorted in the long gas gap. The maximum electron density in the filament is on the order of 10(15)cm(-3). Optical emission examination shows a decrease of optical emissions from OH and Ar but an increase of optical emissions from N2 along the plasma jet. The vapor in the working gas argon rather than in the ambient air dominates the optical emissions from the de-excitation of OH along the plasma jet. Near the ground electrode, the nitrogen emission spectra mainly resulted from the direct electron effect on the ground state or metastable nitrogen and the collisions between nitrogen metastables. The rotational temperature is lower than the vibrational temperature but much higher than the room temperature. This feature makes the filamentary plasma jet only suitable for processing samples bearing high temperature.</p
Semantic Descriptions of High-Resolution Remote Sensing Images
No full textImage captioning has attracted more and more attention in remote sensing filed since it provides more specific information than traditional tasks, such as classification. Though image captioning has gained some developments in recent years, it is difficult to describe the image in one simple sentence. To relieve the limitation, a novel captioning task is proposed and a novel framework is proposed to solve the novel task. The proposed framework uses semantic embedding to measure the image representation and the sentence representation. The captioning performance is improved by a proposed sentence representation (collective representation). Experimental results and human evaluations on three captioning data sets in remote sensing field demonstrate that the proposed framework can lead to advancement in image captioning results. © 2019 IEEE.</p
Research on 940nm kilowatt high efficiency quasi-continuous diode laser bars
No full textHigh-power GaAs-based semiconductor lasers are the most efficient source of energy for converting electrical into optical power. 940nm diode lasers are used directly or as pump sources for Yb:YAG solid-state lasers, and are widely used in laser cladding and other fields. Improving electro-optic conversion efficiency and reliable output power are urgent requirements for current research hotspots and industrial laser systems. In this paper, we use an asymmetric epitaxial structure of InGaAs/AlGaAs, which reduces the optical loss and resistance, and adopt better cavity surface technology to present 940nm 1-cm quasi-continuous micro-channel cooling (MCC) laser bars. The lasers are tested under a high duty cycle of 9.6% (600us,160Hz) at 25°C with output power of 660.05W, electro-optic conversion efficiency of 64.71% at 600A and slope efficiency of 1.16 W/A. The peak efficiency reaches 72.4%. The increased efficiency results from a lower threshold current and a lower series resistance. Furthermore, the output power of 1025W (1000A) has been confirmed at a duty cycle of 4% (400us,100Hz). © 2019 SPIE.</p
Microtapered long period gratings: Non-destructive fabrication, highly sensitive torsion sensing, and tunable broadband filtering
No full textA promising technology for non-destructive fabricating microtapered long period fiber gratings (MT-LPFGs) is demonstrated by periodically slight tapering single-mode fiber. Owing to the optimized microtapering technique, high-quality LPFGs with dip attenuations of about 40 dB, insertion loss © 2019 Elsevier B.V.</p
Antimonide-based visible to short wavelength infrared bispectral photodetector
No full textWe report cylinder photon traps, prism photon traps, and SiO2/Ta2O5 antireflection films added to the active areas of short wavelength infrared detectors. The total device thickness was estimated ∼3.3μm and with the p-i-n structure based on antimonide. The simulation results show that the photon traps increase the absorption of the invisible spectrum distinctly. Also, the optical measurements reveal that maximal responsivity of the detector with PTs array is 0.094A/W in the visible range and 0.64A/W in the short wavelength infrared spectrum. The responsivity in the wavelength of short-wave infrared can be increased apparently as well. Thus, the photon traps array may a potential method for antimonide-based visible to short wavelength infrared bispectral photodetector. © 2019 SPIE. Downloading of the abstract is permitted for personal use only.</p
A Characteristic Extraction Algorithm Based on Blocking Star Images
No full textThe star images obtained through the CCD camera can visually display the star structure. In order to get the wide starry image, we need to extract the characteristics of star images to achieve the star image stitching. In the star images, star points, whose characteristics are limited, are easily influenced by noise and are also difficult to extract. The number of stars is too large to stitch accurately. Thus, we propose a stitching algorithm based on blocking star images. First, we establish the maximum intensity projection model based on time sequence to locate the star points accurately. Then, according to the relative positions of star points, the block model is introduced to realize the establishment of the characteristics. Finally, the star image stitching is achieved from the perspective of the characteristic similarity. The experiments illustrate that CM (combination measure) reaches 0.87, and the proposed algorithm has better anti-noise performance and robustness.</p
一种短波红外连续变焦镜头
No full text本实用新型涉及短波红外成像技术领域，针对现有连续变焦系统在环境温度发生变化时，变焦过程中只在某个焦距位置时图像清晰，其余焦距位置图像模糊甚至不能成像，易造成目标丢失的问题，提供一种短波红外连续变焦镜头。镜头包括前固定组、变倍组、孔径光阑、补偿组以及后固定组；前固定组自左向右依次为第一负透镜、第一双凸正透镜和第一弯月形正透镜；变倍组自左向右依次为第一双胶合透镜和第二双凹负透镜；补偿组自左向右依次为第二双凸正透镜和第二双胶合透镜；后固定组自左向右依次为第三双凹负透镜、第三弯月形正透镜、第三负透镜和第四双凸正透镜；前固定组根据环境温度沿光轴方向左右移动；变倍组与补偿组沿光轴方向左右移动。</p