Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease

The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.

Manipulating d-d orbital hybridization induced by Mo-doped Co_(9)S_(8) nanorod arrays for high-efficiency water electrolysis

Precisely refining the electronic structure of electrocatalysts represents a powerful approach to further optimize the electrocatalytic performance.Herein,we demonstrate an ingenious d-d orbital hybridization concept to construct Mo-doped Co_(9)S_(8) nanorod arrays aligned on carbon cloth(CC)substrate(abbreviated as Mo-Co_(9)S_(8)@CC hereafter)as a high-efficiency bifunctional electrocatalyst toward water electrolysis.It has experimentally and theoretically validated that the 4d-3d orbital coupling between Mo dopant and Co site can effectively optimize the H_(2)O activation energy and lower H^(*)adsorption energy barrier,thereby leading to enhanced hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)activities.Thanks to the unique electronic and geometrical advantages,the optimized Mo-Co_(9)S_(8)@CC with appropriate Mo content exhibits outstanding bifunctional performance in alkaline solution,with the overpotentials of 75 and 234 mV for the delivery of a current density of 10 mA cm^(-2),small Tafel slopes of 53.8 and 39.9 mV dec~(-1)and long-term stabilities for at least 32 and 30 h for HER and OER,respectively.More impressively,a water splitting electrolylzer assembled by the self-supported Mo-Co_(9)S_(8)@CC electrode requires a low cell voltage of 1.53 V at 10 mA cm^(-2)and shows excellent stability and splendid reversibility,demonstrating a huge potential for affordable and scalable electrochemical H_(2) production.The innovational orbital hybridization strategy for electronic regulation herein provides an inspirable avenue for developing progressive electrocatalysts toward new energy systems.

A core-shell copper oxides-cobalt oxides heterostructure nanowire arrays for nitrate reduction to ammonia with high yield rate

Electrochemical nitrate reduction to ammonia(NRA) can realize the green synthesis of ammonia(NH3) at ambient conditions, and also remove nitrate contamination in water. However, the current catalysts for NRA still face relatively low NH3yield rate and poor stability. We present here a core-shell heterostructure comprising cobalt oxide anchored on copper oxide nanowire arrays(CuO NWAs@Co_(3)O_(4)) for efficient NRA. The CuO NWAs@Co_(3)O_(4)demonstrates significantly enhanced NRA performance in alkaline media in comparison with plain CuO NWAs and Co_(3)O_(4)flocs. Especially, at-0.23 V vs. RHE, NH_(3) yield rate of the CuO NWAs@Co_(3)O_(4)reaches 1.915 mmol h^(-1)cm^(-2),much higher than those of CuO NWAs(1.472 mmol h^(-1)cm^(-2)), Co_(3)O_(4)flocs(1.222 mmol h^(-1)cm^(-2)) and recent reported Cu-based catalysts.It is proposed that the synergetic effects of the heterostructure combing atom hydrogen adsorption and nitrate reduction lead to the enhanced NRA performance.

国产FPGA上通信基带发端算法设计和系统实现

该文针对国产FPGA上通信基带算法及相关信号处理算法IP核匮乏现状,设计了基于紫光Logos系列FPGA器件的通信基带发端算法;在紫光FPGA缺乏FIR IP核的情况下,经优化设计实现了仅用7个乘法器的60阶FIR成型滤波器;搭建收发测试环境对设计的发端系统进行了测试。测试结果表明,所设计的基于正交调制的发端基带算法和基带系统性能达到主流水平的技术指标要求,实现了首批通信算法和通信系统在国产FPGA器件上的应用。

Bidirectional visible light absorber based on nanodisk arrays

A perfect bidirectional broadband visible light absorber composed of titanium nitride and tungsten nanodisk arrays is proposed.The average absorption of the absorber exceeds 89%at 400 nm–800 nm when light is normally incident on the front-side.Illumination from the opposite direction(back-side)results in absorption of more than 75%.Through the theoretical analysis of the electric and magnetic fields,the physical mechanism of the broadband perfect absorption is attributed to the synergy of localized surface plasmons,propagating surface plasmons,and plasmonic resonant cavity modes.Furthermore,the absorber also exhibits excellent polarization-independence performance and a high angular tolerance of~30°for both front-and back-side incidence.The designed bidirectional broadband visible light absorber here has wide application prospects in the fields of solar cells and ink-free printing.

同步辐射装置主信号源的扩展方法研究

主信号源是同步辐射装置的关键组成部分之一,它不仅用于产生同步辐射光源各子系统所需的稳定度极高的参考信号,还用于生成整个装置的控制系统所需的高精度工作时钟。一般使用射频信号源作为主信号源,而商业射频信号源一般只配备单输出通道,远远不能满足同步辐射装置的需要,使用传统功分器对主信号通道进行扩展又存在幅度衰减、精度下降且相位不一致的问题。为解决上述问题,利用射频芯片AD9361,研究了对主信号源的单路输出进行扩展的方法。该方法可根据用户需求完成相应数量的信号通道扩展,设计了AD9361芯片和FPGA主控模块相结合的硬件架构。搭建实验平台,开展了射频信号源在C波段扩展的实验研究,对所提出的扩展方法进行实验验证。实验结果表明,该方法能保证扩展信号的幅度、频率与相位与主信号保持高度一致。

基于ZYNQ芯片的基板管理控制器设计与实现

随着超算、云计算等数据中心的大规模发展,主板的架构日益复杂,成本控制越来越严苛,常用的基板管理控制器(BMC)设计方案可扩展功能有限,迫切需要设计一种低成本且高效的BMC方案。提出一种基于Vivado和Yocto Project的集成开发平台,选用XILINX ZYNQ系列FPGA芯片,采用其内部硬核ARM运行的OpenBMC方案。该设计通过AXI总线扩展外设,可扩展性强、灵活性高,从而实现BMC与FPGA的双重管理二合一,节约了主板的空间与成本。

Controllable and large-area growth of ZnO nanosheet arrays under ambient condition as superior anodes for scalable aqueous batteries

Two-dimensional(2D)oxides have been the focus of substantial research interest recently,owing to their fascinating physico-chemical properties.However,fabrication of large-area 2D oxide materials in a controlled manner under mild conditions still remains a formidable challenge.Herein,we develop a facile and universal strategy based on the sonochemistry approach for controllable and large-area growth of quasi-aligned single-crystalline ZnO nanosheets on a Zn substrate(Zn@SC-ZnO)under ambient conditions.The obtained ZnO nanosheets possess the desired exclusively exposed(001)facets,which have been confirmed to play a critical role in significantly reducing the activation energy and facilitating the stripping/plating processes of Zn.Accordingly,the constructed Zn@SC-ZnO||Zn@SC-ZnO symmetric cell has very low polarization overpotential down to~20 mV,with limited dendrite growth and side reactions for Zn anodes.The developed Zn@SC-ZnO//MnO_(2)aqueous Zn-ion batteries(ZIBs)show a voltage efficiency of 88.2%under 500 mA g^(-1)at the stage of 50%depth of discharge,which is state of the art for ZIBs reported to date.Furthermore,the as-assembled large-size cell(5 cm×5 cm)delivers an open circuit potential of 1.648 V,and can be robustly operated under a high current of 20 mA,showing excellent potential for future scalable applications.

Homogenous metallic deposition regulated by abundant lithiophilic sites in nickel/cobalt oxides nanoneedle arrays for lithium metal batteries

Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li utilization.Inducing uniform Li plating/stripping is the core of solving these problems.Herein,we design a highly lithiophilic carbon film with an outer sheath of the nanoneedle arrays to induce homogeneous Li plating/stripping.The excellent conductivity and 3D framework of the carbon film not only offer fast charge transport across the entire electrode but also mitigate the volume change of Li metal during cycling.The abundant lithiophilic sites ensure stable Li plating/stripping,thereby inhibiting the Li dendritic growth and"dead"Li formation.The resulting composite anode allows for stable Li stripping/plating under 0.5 mA cm^(-2) with a capacity of 0.5 mA h cm^(-2) for 4000 h and 3 mA cm^(-2) with a capacity of3 mA h cm^(-2) for 1000 h.The Ex-SEM analysis reveals that lithiophilic property is different at the bottom,top,or channel in the structu re,which can regulate a bottom-up uniform Li deposition behavior.Full cells paired with LFP show a stable capacity of 155 mA h g^(-1) under a current density of 0.5C.The pouch cell can keep powering light-emitting diode even under 180°bending,suggesting its good flexibility and great practical applications.

Developing Three-Dimensional Beamshaping Techniques on Volumetric Random Arrays to Suppress Array Sidelobes

This paper proposes a three-dimensional (3-D) amplitude tapering technique on volumetric random arrays to minimize array sidelobes and emulate phased array operations on mobile platforms. Our ultimate goal is to realize wireless phased array applications carried out by mobile platforms;in this paper, we focus on the development of collaborative beamforming algorithms. This beamshaping technique mitigates the discontinuity of the current distribution along the array aperture and lower array sidelobe level (SLL) by specially paying attention to the array element’s depth deviation. In this work, step by step amplitude tapering procedures are clearly illustrated. Further, a reconfigurable phased array with sixteen patch antennas is tested to verify the fidelity of the 3-D beamshaping algorithm. Measured and simulated radiation patterns are benchmarked to evaluate the sidelobe suppression results, and the best sidelobe suppressed region is around the array’s main beam.

Shear wave splitting analysis of local earthquakes from dense arrays in Shimian,Sichuan

The Shimian area of Sichuan sits at the junction of the Bayan Har block.Sichuan-Yunnan rhombic block,and Yangtze block,where several faults intersect.This region features intense tectonic activity and frequent earthquakes.In this study,we used local seismic waveform data recorded using dense arrays deployed in the Shimian area to obtain the shear wave splitting parameters at 55 seismic stations and thereby determine the crustal anisotropic characteristics of the region.We then analyzed the crustal stress pattern and tectonic setting and explored their relationship in the study area.Although some stations returned a polarization direction of NNW-SSE.a dominant polarization direction of NW-SE was obtained for the fast shear wave at most seismic stations in the study area.The polarization directions of the fast shear wave were highly consistent throughout the study-area.This orientation was in accordance with the direction of the regional principal compressive stress and parallel to the trend of the Xianshuihe and Daliangshan faults.The distribution of crustal anisotropy in this area was affected by the regional tectonic stress field and the fault structures.The mean delay time between fast and slow shear waves was 3.83 ms/km.slightly greater than the values obtained in other regions of Sichuan.This indicates that the crustal media in our study area had a high anisotropic strength and also reveals the influence of tectonic complexity resulting from the intersection of multiple faults on the strength of seismic anisotropy.

基于FPGA的小目标识别分类系统的设计与实现

为了提高小目标识别和分类的实时性,同时降低识别系统的资源消耗,本文提出了一种简易、高效的现场可编程门阵列(Field Programmable Gate Array,FPGA)小目标识别分类系统。该系统首先通过图像预处理消除图像噪点,并采用并行计算提升系统实时性。然后将处理后的图像与模板进行匹配计算得到识别结果,设计的模板匹配电路具有较小的硬件复杂度和较快的处理速度。实验结果表明,本文所提出的识别系统在680×480图像分辨下,可达137.5帧/s的处理速度,实时性强,同时仅消耗了9个块随机存储器(Block Random Access Memory,BRAM)和2个数字信号处理器(Digital Signal Processor,DSP),硬件资源消耗较少,在处理小目标识别和分类问题上有较好的实用价值。

Influence of MnO_(x)deposition on TiO_(2)nanotube arrays for electrooxidation

TiO_(2)has demonstrated outstanding performance in electrochemical advanced oxidation processes(EAOPs)due to its structural stability and high oxygen overpotential.However,there is still much room for improving its electrochemical activity.Herein,narrow bandgap manganese oxide(MnO_(x))was composited with TiO_(2)nanotube arrays(TiO_(2)NTAs)that in-situ oxidized on porous Ti sponge,forming the MnO_(x)-TiO_(2)NTAs anode.XANES and XPS analysis further proved that the composition of MnO_(x)is Mn2O3.Electrochemical characterizations revealed that increasing the composited concentration of MnO_(x)can improve the conductivity and reduce oxygen evolution potential so as to improve the electrochemical activity of the composited MnO_(x)-TiO_(2)NTAs anode.Meanwhile,the optimal degradation rate of benzoic acid(BA)was achieved using MnO_(x)-TiO_(2)NTAs with a MnO_(x)concentration of 0.1 mmol L^(-1),and the role of MnO_(x)was proposed based on DFT calculation.Additionally,the required electrical energy(EE/O)to destroy BA was optimized by varying the composited concentration of MnO_(x)and the degradation voltage.These quantitative results are of great significance for the design and application of high-performance materials for EAOPs.

道路平整度检测多源数据高精度同步采集

随着使用年限增加,道路出现了不平整等路面损坏情况,急需一种快速、有效的道路平整度检测设备对道路进行检测。设计了一种道路平整度检测多传感器数据同步采集系统,以FPGA为控制核心,利用GPS输出的NEMA数据和高稳晶振建立高精度的时间基准,采用A/D采样的方式进行同步数据采集。为提高系统的抗干扰能力和数据采样的精度,传感器信号调理电路采用差分放大和抗混叠滤波设计。实验结果表明,该系统完成了多传感器数据高精度同步采集,时间同步精度为微秒级,能够为评价路面平整度提供高精度原始数据,具有数据采样精度高、稳定性好、抗干扰能力强、成本低等优点,已在武汉夕睿光电技术有限公司的道路检测车上得到成功应用。

基于FPGA的自滑动同步法TFT-LCD屏TCON的实现

不同厂家、不同尺寸、不同分辨率的TFT-LCD屏与时序控制器TCON的接口不同,对应不同的差分信号格式。为了适应不同屏的图像显示,需要一种可编程的时序控制器TCON。通过在FPGA芯片上采用自滑动同步法,实现了TFT-LCD屏的TCON系统。该系统从视频处理主板输出的差分信号中提取视频数据,提出通过自滑动同步法使之与同步控制信号对齐;将提取的视频数据转换为源驱动器的输入信号,即mini-LVDS或RSDS格式的差分信号,同时产生门驱动器的时序信号;由源驱动器和门驱动器输出的信号驱动TFT-LCD屏显示图像信号。为了测试TCON的性能,使用两块FPGA电路板进行实验。一块FPGA电路板实现TCON时序控制器;另一块作为TCON的输入测试信号源,用于测试所设计的TCON性能。实验结果显示,所设计的TCON能够从LVDS视频差分数据中正确解析出视频数据,并转换为屏的源驱动器和门驱动器信号,驱动TFT-LCD屏显示视频信号。通过对比分析可知,使用自滑动同步法具有资源消耗少,功耗较低等优点。

Atomic Dispersion of Rh on Interconnected Mo_(2)C Nanosheet Network Intimately Embedded in 3D Ni_(x)MoO_(y) Nanorod Arrays for pH-Universal Hydrogen Evolution

Herein,a simple synthetic approach is employed for the atomic dispersion of Rh atoms(Rh SAs)over the surface of interconnected Mo_(2)C nanosheets intimately embedded in a three-dimensional Ni_(x)MoO_(y)nanorod arrays(Ni_(x)MoO_(y)NRs)framework;we found that the introduction of both isolated Rh SAs and Ni_(x)MoO_(y)NRs adjusts the electrocatalytic function of the host Mo_(2)C toward the direction of being an advanced and highly stable electrocatalyst for efficient hydrogen evolution at pH-universal conditions.As a result,the proposed catalyst outperforms most recently reported transition metal-based catalysts,and its performance even rivals that of commercial Pt/C,as demonstrated by its ultralow overpotentials of 31.7,109.7,and 95.4 mV at a current density of 10 mA cm^(-2),along with its small Tafel slopes of 42.4,51.2,and 46.8 mV dec^(-1)in acidic,neutral,and alkaline conditions,respectively.In addition,the catalyst shows remarkable long-term stability over all pH values with good maintenance of its catalytic activity and structural characteristics after continuous operation.

基于在线自组织增量学习的非侵入式负荷识别方法

随着电子技术智能化的发展,对实现电器负荷使用情况的精准识别在智慧用电领域将有广泛的用户需求。为了实现对电器设备的实时在线精确监测,本文提出了一种基于在线自组织增量学习(SOINN)的非侵入式负荷识别方法。该方法包含负荷特征提取、负荷特征分类及电器识别2个步骤。在负荷特征提取步骤中,提出了包含奇次谐波、均值、方差、3阶矩、4阶矩、电流有效值、功率谱峰值、功率谱谷值在内的共12维特征的特征提取方案。在负荷特征分类及电器识别步骤中,提出了结合SVM的SOINN的负荷特征分类及电器识别方法,以克服传统的SOINN算法不能实现电器类型识别功能的缺陷。通过C++语言将所提方法中的功能算法编写成微处理器系统的可执行功能模块,将功能模块移植部署在SoCFPGA的HPS端运行,实现了FPGA和HPS之间的协同高速数据通信。选取了8种常规家用电器作为负荷识别对象,搭建了基于SoCFPGA的硬件实验平台,进行了最优负荷特征选取,并采用本文方法对单电器与多电器的在线负荷进行了识别。实验结果:选取12维特征为本文方法的最优特征组合;本文方法的单电器与多电器的识别率均在95%以上。本文提出的负荷识别方法能够有效、准确地识别单电器与多电器;系统可实施性强,灵活性高,具有在线学习的优越性与实际应用的切实可行性。

基于卷积神经网络的岩渣分类算法及其FPGA加速

全断面岩石掘进机在道路掘进过程中,刀盘挤压切削岩体容易产生刀盘磨损及损坏,从而造成经济损失,因此需要检测刀盘磨损的理论和技术来指导施工。岩渣是掘进过程的直接产物,携带丰富的信息,能够反映当前的施工状况,因此可以通过岩渣识别利用这些信息间接实现对刀盘的监测。提出了一种基于卷积神经网络的岩渣识别算法,在岩渣数据集上实现了96.5%的分类准确率。随后为了便于FPGA硬件部署,提出一种网络压缩方法,将网络规模压缩到原始网络的2.28%,同时分类准确率相比原网络仅下降了0.9%。最后使用OpenCL技术在Intel Arria 10 GX1150平台上实现了算法部署,达到了224.54 GOP/s的吞吐率以及11.23 GOP/s/W的能效比。

基于卷积神经网络的多工况多传感滚动轴承实时监控方法

针对工业环境中广泛在多工况下多滚动轴承实时状态监测的需求和部署环境受限的挑战,提出一种基于卷积神经网络(Convolutional Neural Network,CNN)的面向多传感器滚动轴承运行状态监控方法。该方法将两个不同工况下的一维时间序列数据集以均方根(Root Mean Square,RMS)指标标注,并通过将一维时间序列多传感器数据重构为二维空间张量的形式输入卷积神经网络训练。最后利用层融合和16比特量化优化,将网络部署到FPGA上,用以解决CNN的计算开销。实验结果表明,在结合了两种不同工况的数据集下,网络测试推理准确度依然高达99.24%,比多层感知机实现高10.48%,比多层感知机结合支持向量机的实现高2.91%,该算法对于新加入的数据集也有较强的鲁棒性,经过重训练,新加入的数据集准确率可以达到99.17%。基于FPGA部署优化的网络的峰值能效为76.217GPOS/W,为CPU实现的33.09倍,GPU实现的5.39倍。其中,16比特精度部署的网络测试精度相较32比特精度实现仅降低0.001%。

基于图像处理的电路板缺陷检测系统设计

针对传统电路板缺陷检测多为人工检测、速度较慢且成本较高的问题,本文研究设计了一款以图像处理为基础、利用现场可编程门阵列(FPGA)实现对电路板缺陷准确、高速的检测系统。在传统图像增强算法的基础上提出一种针对不同图像信息采用不同感兴趣区间的方法,增强效果显著;为减少电路板上标识字样对匹配算法计算速度的影响,提出一种去除丝印算法,将电路板上多余的标识字样取消,减少图像匹配的计算量,加快检测的速度;在传统绝对误差和算法(SAD)模板匹配算法的基础上采用去平均值法计算图像信息,减小光照变化带来的影响;将传统2算子Sobel边缘检测扩展到8算子边缘检测,边缘信息更加明显清晰。采用FPGA作为硬件平台,在Vivado开发环境下实现Verilog HDL硬件逻辑语言,下载到FPGA中实现。实验结果表明,系统的平均检测精度为98.53%,检测单张电路板的时间为8.204 s。本系统设计在检测精度和速度上都有明显提升,且造价成本低。