Ultra-thin Body Buried In0.35Ga0.65As Channel MOSFETs with Extremely Low Off-current on Si Substrates

In this paper, we investigated the electrical properties of the Metal-oxide-semiconductor gate stack of Ti/Al2O3/InP under different annealing conditions. A min...     

Investigation on the Peroxidase-like Activity of Vitamin B6 and Its Applications in Colorimetric Detection of Hydrogen Peroxide and Total Antioxidant Capacity Evaluation

The peroxidase-like activity of vitamin B6 (VB6) was firstly demonstrated by catalyzing the peroxidase chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) at the existence of H₂O₂. The influence of different factors on the catalytic property of VB6, including pH, temperature, VB6 concentration, and incubation time, were investigated. The steady-state kinetic study results indicate that VB6 possesses higher affinity to H₂O₂ than natural horseradish peroxidase and some other peroxidase mimics. Besides, the radical quenching experiment results confirm that hydroxyl radical (•OH) accounts for the catalytic process. Based on the excellent peroxidase-like catalytic activity of VB6, the colorimetric methods for H₂O₂ and gallic acid (GA) detection were developed by measuring the absorbance variance of the catalytic system. Under the optimal conditions, the linear ranges of the methods for H₂O₂ and GA determination with good selectivity are 50.0–600.0 μM and 10.0–50.0 μM, respectively. In addition, the developed method was applied in the detection of H₂O₂ in milk samples and evaluation of total antioxidant capacity of different tea infusions. This study may broaden the application prospect of VB6 in environmental and biomedical analysis fields, contribute to profound insight of the physiological functions of VB6, as well as lay foundation for further excavation of small-molecule peroxidase mimics.     

基于知识蒸馏与改进ViT网络的花卉图像细粒度分类

由于自然条件下拍摄的花卉图像背景复杂,而且其存在类内差异性大和类间相似性高的问题,现有主流方法仅依靠卷积模块提取花卉的局部特征难以实现准确的细粒度分类。针对上述问题,本文提出了1种高精度、轻量化的花卉分类方法(ConvTrans-ResMLP),通过结合Transformer模块和残差MLP(multi-layer perceptron)模块实现对花卉图像的全局特征提取,并在Transformer模块中加入卷积计算使得模型仍保留提取局部特征的能力;同时,为了进一步将花卉分类模型部署到边缘设备中,本研究基于知识蒸馏技术实现对模型的压缩与优化。实验结果表明,本文所提出的方法在Oxford 17、Oxford 102和自制的Flowers 32数据集上的准确率分别达98.62%、97.61%和98.40%;知识蒸馏后本文的轻量化模型的大小约为原来的1/18,而准确率仅下降2%左右。因此,本研究能较好地提升边缘设备下花卉细粒度分类的效率,对促进花卉培育的自动化发展具有切实意义。     

动目标显示雷达模拟器地物回波单元的设计和实现

在分析了地物杂波回波特性的基础上,首先设计了动目标显示雷达模拟器的地物回波形成单元的组成方框图.结合方框图,得出了形成地物回波的基本要素:同步计数电路、计数比较电路、多普勒调制电路.最后结合雷达自身的特点,设计了动目标显示雷达模拟训练器地物回波形成单元的基本组成电路,并将其与雷达联机,取得良好的效果.     

电子战武器装备发展现状与展望

介绍了电子战武器装备在战争中的地位与作用,分析了目前国内外电子战武器装备的发展现状,同时展望了电子战武器装备的发展趋势。     

Collaborative Multiple Access And Energy-Efficient Resource Allocation in Distributed Maritime Wireless Networks

With the rapid increasing of maritime activities, maritime wireless networks(MWNs) with high reliability, high energy efficiency, and low delay are required. However, the centralized networking with fixed resource scheduling is not suitable for MWNs due to the special environment. In this paper,we introduce the collaborative relay communication in distributed MWNs to improve the link reliability, and propose an orthogonal time-frequency resource block reservation based multiple access(RRMA) sche...     

Cardiac-specific overexpression of Ndufs1 ameliorates cardiac dysfunction after myocardial infarction by alleviating mitochondrial dysfunction and apoptosis

Myocardial infarction (MI) is the leading cause of premature death among adults. Cardiomyocyte death and dysfunction of the remaining viable cardiomyocytes are the main pathological factors of heart failure after MI. Mitochondrial complexes are emerging as critical mediators for the regulation of cardiomyocyte function. However, the precise roles of mitochondrial complex subunits in heart failure after MI remain unclear. Here, we show that NADH:ubiquinone oxidoreductase core subunit S1 (Ndufs1) expression is decreased in the hearts of heart failure patients and mice with myocardial infarction. Furthermore, we found that cardiac-specific Ndufs1 overexpression alleviates cardiac dysfunction and myocardial fibrosis in the healing phase of MI. Our results demonstrated that Ndufs1 overexpression alleviates MI/hypoxia-induced ROS production and ROS-related apoptosis. Moreover, upregulation of Ndufs1 expression improved the reduced activity of complex I and impaired mitochondrial respiratory function caused by MI/hypoxia. Given that mitochondrial function and cardiomyocyte apoptosis are closely related to heart failure after MI, the results of this study suggest that targeting Ndufs1 may be a potential therapeutic strategy to improve cardiac function in patients with heart failure.Subject terms: Heart failure, Myocardial infarction, Myocardial infarction     

A high-precision and 10 bit two-step Time-to-Digital Converter for TOF application

A two-step high-precision Time-to-Digital Converter(TDC), integrated with a Single-Photon Avalanche Diode(SPAD), used for Time-Of-Flight(TOF) application, has been developed and tested. Time interval measurement is performed by the coarse counter and fine interpolator, which are utilized to measure the total periods and the residue time of the reference clock, respectively. Following a detail analysis of time precision and clock jitter in the two-step structure, the prototype TDC fabricated in GSMC 1P6M 0.18 μm CMOS Image Sensor(CIS) technology exhibits a Single-Shot Precision(SSP) of 11.415 ps and a dynamic range of 216.7 ns. In addition, a pixel of the chip occupies 100 μm×100 μm, and the measured Integral Nonlinearity(INL) and Differential Nonlinearity(DNL) are better than ±0.88 LSB and ±0.67 LSB, respectively. Meanwhile, the overall power consumption of the chip is 35 mW at 1.8 V power supply. Combined with these characteristics, the designed chip is suitable for TOF-based ranging applications.     

Promote the conductivity of solid polymer electrolyte at room temperature by constructing a dual range ionic conduction path

Poly(ethylene oxide)(PEO) is a classic matrix model for solid polymer electrolyte which can not only dissociate lithium-ions(Li+),but also can conduct Li+through segmental motion in long-range.However,the crystal aggregation state of PEO restricts the conduction of Li⁺ especially at room temperature.In this work,an amorphous polymer electrolyte with ethylene oxide(EO) and propylene oxide(PO) block structure(B-PEG@DMC) synthesized by the transesterification is firstly obtained,showing ...     

基于激光器RIN抑制的宽带低噪声微波光传输技术

微波光子链路中的核心器件激光器、调制器、光电探测器均为有源器件,在微波信号的电光光电转换过程中会引入额外的噪声,导致微波信号的噪声性能恶化,高的噪声系数会降低电子信息系统的灵敏度、动态范围、探测精度等关键性能指标,因此抑制噪声成为实现高性能微波光子系统的关键。文章针对当前激光器噪声较高的限制,提出采用常规分布反馈(DFB)激光器与光放大器、窄带光子滤波相组合的方式来抑制激光源噪声,实现微波光子链路的宽带低噪声。建立了微波光子链路传输模型,分析了链路性能与器件参数之间的映射关系。实测对比了采用该组合光源方案与常规微波光子链路的噪声性能,结果表明采用高功率光源结合光滤波可对激光器远端相对强度噪声(RIN)实现高的抑制,通过优化,噪声系数较常规水平可改善15 dB以上。