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891.
论述了合成孔径雷达(Synthetic Aperture Radar,SAR)实时成像处理转置存储器(Corner Turning Memory,CTM)的功能和原理,提出了一种基于SDRAM的星载SAR星上实时成像处理CTM系统实现方案。考虑到星上环境对器件的抗辐照要求,系统选用一片XQB2V500 FPGA做控制器,主存储器选用三片Micron公司的MT48LC16A2 SDRAM。系统采用三页式结构,输入输出并行处理。文章分析了系统输入、输出接口时序,给出了详细的硬件实现和测试结果。实验结果表明该CTM系统方案可行,能够应用在星上实时成像处理器中。  相似文献   
892.
杨洋  黄征  金涛 《现代电子技术》2007,30(21):144-147
在电子不停车收费系统(ETC)和我国现行的人工半自动收费系统(MTC)的基础上,提出了基于ETC和MTC的高速公路组合式联网收费系统的设计方案。本文对ETC车道和MTC车道的硬件系统(包括通信子系统、车辆自动分类子系统、视频监控子系统)和软件系统(包括ETC车道收费子系统、MTC车道收费子系统、收费站服务器系统、中心服务器系统和用户服务子系统)分别进行了阐述,验证了本系统的可行性。  相似文献   
893.
黄征  宋焕生  王国强 《电视技术》2007,31(12):87-89
系统采用成像控制和激光补光技术,使成像质量不受外界光线变化的影响,达到全天候32作和应用的要求。同时提出了一种检测车辆及其速度的算法,并将该算法应用到本系统中。实验结果表明,该系统可以全天候准确地检测出车辆及其速度。  相似文献   
894.
In this paper,a two-function light source is recommended. It can both amplify the light power and demodulate the wave-length signal. Its output power is 1000 times as high as traditional broadband light source(BBS) and it can demodulate the signal by scanning wavelength in 30 nm of bandwidth range in the situation of 1550 nm central wavelength. This kind of light source effectively solves the problem of light energy supply in more-point measurement of FBG and simplifies the structure of sensing measurement.  相似文献   
895.
赵深  何巍  辛璟焘  吕峥 《压电与声光》2023,45(4):589-594
光纤陀螺是惯导系统的重要组成器件,环境温度变化会造成光纤陀螺的零偏发生漂移,从而降低测量精度。运用传统的BP神经网络进行预测易陷入局部极小值,导致补偿失败。该文采用混沌模拟退火粒子群BP神经网络的光纤陀螺零偏温度补偿模型,优化了网络参数。通过在-40~60℃的升降温实验对模型进行验证,实验结果表明,该温度补偿模型的零偏稳定性比补偿前约有70%的精度提升,与以往BP模型相比,其预测性能和补偿效果更好。  相似文献   
896.
All-optical responsive nanomaterials, which can rapidly switch between two stable states, have been regarded as the next-generation memories due to their potential to realize binary information storage and implement on-chip, integrated photonic neuromorphic systems. Rare earth oxides are preeminent candidates owing to their extraordinary luminescent stability and narrow optical transitions. However, due to the lack of simple and effective optical switches, it is difficult to realize all-optical data storage, encoding, and retrieval by pure rare earth-doped luminescent nanoparticles. Here, a rapid and high-contrast of 104 luminescent switching of Y2O3:Eu3+ nanoparticle between the enhancement and quenching states is achieved by employing the strong light confinement and ultrafast thermal response of localized surface plasmon resonance. A self-encrypted all-optical memory is presented with optical information writing, encryption, reading, and re-writing, and a high-sensitivity synaptic response of emitters to frequency and light intensity flux, which can be harnessed to encrypt information flows and promote convenient and high-security information encryption. Such a convenient and secure plasmonic thermally assisted self-encrypting luminescent switch paves the way for constructing high-performance stimuli-responsive rare earth oxide crystals on demand and expanding their applications in various data encryption, anti-counterfeiting, and rewritable colouration devices.  相似文献   
897.
The pentacene-based organic field effect transistor (OFET) with a thin transition metal oxide (WO3) layer between pentacene and metal (AI) source/drain electrodes was fabricated. Compared with conventional OFET with only metal AI source/drain electrodes, the introduction of the WO3 buffer layer leads to the device performance enhancement. The effective field-effect mobility and threshold voltage are improved to 1.90 em2/(V.s) and 13 V, respectively. The performance improvements are attributed to the decrease of the interface energy barrier and the contact resistance. The results indicate that it is an effective approach to improve the OFET performance by using a WO3 buffer layer.  相似文献   
898.
Materials-based antigen delivery systems can augment the immune response by improving antigen uptake in antigen-presenting cells, targeting lymph nodes, prolonging antigen exposure, enhancing cross-presentation, etc. Recent research revealed that some antigen carriers activate the innate immune pathways without additional adjuvant. Here, a vaccine delivery platform (antigen nanocapsules) constructed by a one-step in situ polymerization is reported, weaving a biodegradable polymer network around the antigen surface. This simple technology allowed us to study the immunomodulatory effect of various antigen carriers. An antigen nanocapsule (NC7) capable of inducing dendritic cell activation and cross-presentation is identified. Further mechanistic studies revealed that NC7 activated the cGAS-STING pathway in a cGAS-dependent manner. Moreover, the subcutaneously injected NC7 accumulated in the lymph nodes and elicited strong cytotoxic T cell immunity and T cell memory against established cancer. Collectively, the often-neglected immunomodulatory effect of various cationic antigen carriers, enabling potential application in cancer vaccines, is uncovered.  相似文献   
899.
Alloying-type metal sulfides with high theoretical capacities are promising anodes for sodium-ion batteries, but suffer from sluggish sodiation kinetics and huge volume expansion. Introducing intercalative motifs into alloying-type metal sulfides is an efficient strategy to solve the above issues. Herein, robust intercalative In S motifs are grafted to high-capacity layered Bi2S3 to form a cation-disordered (BiIn)2S3, synergistically realizing high-rate and large-capacity sodium storage. The In S motif with strong bonding serves as a space-confinement unit to buffer the volume expansion, maintaining superior structural stability. Moreover, the grafted high-metallicity Indium increases the bonding covalency of Bi S, realizing controllable reconstruction of Bi S bond during cycling to effectively prevent the migration and aggregation of atomic Bi. The novel (BiIn)2S3 anode delivers a high capacity of 537 mAh g−1 at 0.4 C and a superior high-rate stability of 247 mAh g−1 at 40 C over 10000 cycles. Further in situ and ex situ characterizations reveal the in-depth reaction mechanism and the breakage and formation of reversible Bi S bonds. The proposed space confinement and bonding covalency enhancement strategy via grafting intercalative motifs can be conducive to developing novel high-rate and large-capacity anodes.  相似文献   
900.
陈杰智  李泠  施毅  刘明  郑有炓 《半导体学报》2005,26(8):1671-1675
根据硅各向异性腐蚀在微观尺度下的特点,基于元胞自动机理论提出了新的腐蚀模拟模型.该模型考虑了腐蚀过程中硅不同晶面的晶体结构特点,并通过引入碰撞理论,综合反映了腐蚀温度和浓度对腐蚀的影响作用.该模型可快速准确地模拟分析各向异性腐蚀工艺过程,对优化工艺有着理论指导作用.  相似文献   
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