由于传统的互补金属-氧化物-半导体(Complementary Metal Oxide Semiconductor,CMOS)神经元电路与生物学的契合性较差且电路复杂,提出了一种基于忆阻器的多端口输入的泄露-整合-激发(Leaky-Integrate-Fire,LIF)神经元电路。该电路由运...由于传统的互补金属-氧化物-半导体(Complementary Metal Oxide Semiconductor,CMOS)神经元电路与生物学的契合性较差且电路复杂,提出了一种基于忆阻器的多端口输入的泄露-整合-激发(Leaky-Integrate-Fire,LIF)神经元电路。该电路由运放、逻辑门等器件以及忆阻器构成,主要分为信号叠加模块和神经元信号产生模块。通过施加多个双尖峰脉冲信号并调节输入信号的数量和频率,模拟了生物神经元受到的不同程度刺激。研究发现施加到神经元上信号的数量和频率达到一定的值,神经元电路才会输出电压信号,这与生物体中只有受到一定程度的刺激时才会做出反应的现象是一致的。进一步,调节该电路中神经元信号产生模块的阈值电压大小,研究发现输入相同的信号,只有当电路的阈值电压较低时,神经元电路才能输出电压信号,这与生物中不同部位受到相同的刺激,神经元兴奋程度越高,越容易做出反应的现象一致。由此,该文所提出的LIF神经元电路不仅解决了传统电路输入信号单一、输入信号波形与生物信号波形差异大等问题,而且能模拟生物神经元的兴奋程度,这为人工神经网络的设计提供理论依据。展开更多
目的:探究棕榈酸(PA)对血管纹边缘细胞(MCs)损伤的机制。方法:从新生3 d FVB/NJ乳鼠颞骨解剖出耳蜗,游离出血管纹后用胶原酶Ⅱ消化并离心,得到原代血管纹边缘细胞。通过CCK-8法确定合适的PA浓度并设置对照组(0μmol·L^(-1)PA)与实...目的:探究棕榈酸(PA)对血管纹边缘细胞(MCs)损伤的机制。方法:从新生3 d FVB/NJ乳鼠颞骨解剖出耳蜗,游离出血管纹后用胶原酶Ⅱ消化并离心,得到原代血管纹边缘细胞。通过CCK-8法确定合适的PA浓度并设置对照组(0μmol·L^(-1)PA)与实验组(100~1000μmol·L^(-1)PA)。采用细胞流式术检测不同组边缘细胞凋亡情况,以及通过蛋白免疫印迹实验确定边缘细胞中自噬相关蛋白与炎症因子的表达情况。结果:随着PA浓度升高,边缘细胞细胞活力显著降低。与对照组相比,边缘细胞的凋亡比例随着PA浓度的升高而升高。同时,实验组自噬相关蛋白LC-3Ⅱ、SQSTM1/p62及炎症相关因子NF-κB、p-NF-κB蛋白表达显著高于对照组。结论:棕榈酸可导致边缘细胞中NF-κB通路激活及自噬功能障碍,二者可协同作用引起边缘细胞损伤。展开更多
煤地质学是应用地质学与地球化学的理论和方法研究煤层、煤系及其共伴生矿产资源的物质组成、成因、物理和化学性质及其空间展布规律等的学科。在国家倡导生态文明绿色发展以及2030年前实现碳达峰的战略目标背景下,煤地质学的研究重点...煤地质学是应用地质学与地球化学的理论和方法研究煤层、煤系及其共伴生矿产资源的物质组成、成因、物理和化学性质及其空间展布规律等的学科。在国家倡导生态文明绿色发展以及2030年前实现碳达峰的战略目标背景下,煤地质学的研究重点也在逐渐发生变化。通过对2016~2020年在International Journal of Coal Geology期刊上发表的文章进行统计分析,阐述了中国煤地质学的发展进程,重点探讨了煤地质学当前的研究热点内容,提出了煤地质学未来可能的发展方向。结果发现:中国学者在该期刊上发表论文数量最多,占27.4%,其次为美国和澳大利亚;按第一作者所属单位依次为中国矿业大学(北京)、昆士兰大学和中国地质大学(北京);按研究方向,煤岩学和有机地球化学方向的论文数量最多,占31.3%,是近5年的研究热点;其次是煤中矿物质、微量元素与地球化学和煤系气方向;预测未来煤炭洁净化利用方向的研究将逐渐增多,与煤地质学相关的交叉学科也将快速发展。展开更多
Current image inpainting models are primarily designed to achieve a large receptive field(RF)using refinement networks to incorporate different scales.However,these models fail to adapt the use of different RFs to the...Current image inpainting models are primarily designed to achieve a large receptive field(RF)using refinement networks to incorporate different scales.However,these models fail to adapt the use of different RFs to the specific patterns of image damage,resulting in artifacts and semantic information confusion in repaired images.To address the problems of artifacts and semantic information confusion,inspired by different sensitivities of different RFs to inpainting the same image damaged patterns,this study proposes an image inpainting method based on multiple receptive fields(MRFs)and dynamic matching of damaged patterns.First,the parallel filter banks are used to extract the MRF feature groups.Second,the features are dynamically weighted and screened,guided by the mask image,to construct a relationship that adaptively matches the most relevant RF to each specific damaged pattern.A fast Fourier convolution based decoder is used to enhance the fusion of global contextual features during the reconstruction of high dimensional features into low dimensional images.Comparative experimental results show that the proposed method achieves better subjective and objective inpainting results on three public datasets:Paris StreetView,CelebA-HQ,and Places2.展开更多
As a key building block of the biological cortex,synapses are powerful information processing units that enable highly complex nonlinear computations.The realization of artificial synapses with similar capabilities ha...As a key building block of the biological cortex,synapses are powerful information processing units that enable highly complex nonlinear computations.The realization of artificial synapses with similar capabilities has important implications for building intelligent,neuromorphic systems.Here,we demonstrate an artificial synapse based on NbO_(x) nonvolatile memristor to mimic multifunctional bionic applications such as nociceptor and associative learning.Combined experimental characterization with COMSOL simulation,the traditional resistance switching characteristics,which are the decisive factor for the synapse properties are in-depth analyzed.It can be proposed that the I-V characteristics of Pt/NbO_(x)/TiN memristor are governed by core-shell filaments consisting of the shell region of sub-stoichiometric Nb_(2)O_(5-δ)and the core of NbO_(2).On the basis of the core-shell filament model,it can be reasonably explained that Ohmic conduction and Poole-Frenkel conduction take turns to dominate the current flowing in the memristive device,leading to the zigzag evolution of current during the operation process of NbO_(x)-based device.The simulations of synaptic plasticity,including long-term potentiation/depression(LTP/LTD),paired-pulse facilitation(PPF),and spike-timing-dependent plasticity(STDP),exhibiting that the NbO_(x) can be utilized for an artificial synapse.Furthermore,bionic functions such as hyperalgesia and allodynia of a nociceptor and a series of associative learning behaviors in Pavlovian dog experiment are mimicked,illustrating that the Pt/NbO_(x)/TiN have great potential for highly simplified artificial neural network applications.展开更多
文摘由于传统的互补金属-氧化物-半导体(Complementary Metal Oxide Semiconductor,CMOS)神经元电路与生物学的契合性较差且电路复杂,提出了一种基于忆阻器的多端口输入的泄露-整合-激发(Leaky-Integrate-Fire,LIF)神经元电路。该电路由运放、逻辑门等器件以及忆阻器构成,主要分为信号叠加模块和神经元信号产生模块。通过施加多个双尖峰脉冲信号并调节输入信号的数量和频率,模拟了生物神经元受到的不同程度刺激。研究发现施加到神经元上信号的数量和频率达到一定的值,神经元电路才会输出电压信号,这与生物体中只有受到一定程度的刺激时才会做出反应的现象是一致的。进一步,调节该电路中神经元信号产生模块的阈值电压大小,研究发现输入相同的信号,只有当电路的阈值电压较低时,神经元电路才能输出电压信号,这与生物中不同部位受到相同的刺激,神经元兴奋程度越高,越容易做出反应的现象一致。由此,该文所提出的LIF神经元电路不仅解决了传统电路输入信号单一、输入信号波形与生物信号波形差异大等问题,而且能模拟生物神经元的兴奋程度,这为人工神经网络的设计提供理论依据。
文摘目的:探究棕榈酸(PA)对血管纹边缘细胞(MCs)损伤的机制。方法:从新生3 d FVB/NJ乳鼠颞骨解剖出耳蜗,游离出血管纹后用胶原酶Ⅱ消化并离心,得到原代血管纹边缘细胞。通过CCK-8法确定合适的PA浓度并设置对照组(0μmol·L^(-1)PA)与实验组(100~1000μmol·L^(-1)PA)。采用细胞流式术检测不同组边缘细胞凋亡情况,以及通过蛋白免疫印迹实验确定边缘细胞中自噬相关蛋白与炎症因子的表达情况。结果:随着PA浓度升高,边缘细胞细胞活力显著降低。与对照组相比,边缘细胞的凋亡比例随着PA浓度的升高而升高。同时,实验组自噬相关蛋白LC-3Ⅱ、SQSTM1/p62及炎症相关因子NF-κB、p-NF-κB蛋白表达显著高于对照组。结论:棕榈酸可导致边缘细胞中NF-κB通路激活及自噬功能障碍,二者可协同作用引起边缘细胞损伤。
文摘煤地质学是应用地质学与地球化学的理论和方法研究煤层、煤系及其共伴生矿产资源的物质组成、成因、物理和化学性质及其空间展布规律等的学科。在国家倡导生态文明绿色发展以及2030年前实现碳达峰的战略目标背景下,煤地质学的研究重点也在逐渐发生变化。通过对2016~2020年在International Journal of Coal Geology期刊上发表的文章进行统计分析,阐述了中国煤地质学的发展进程,重点探讨了煤地质学当前的研究热点内容,提出了煤地质学未来可能的发展方向。结果发现:中国学者在该期刊上发表论文数量最多,占27.4%,其次为美国和澳大利亚;按第一作者所属单位依次为中国矿业大学(北京)、昆士兰大学和中国地质大学(北京);按研究方向,煤岩学和有机地球化学方向的论文数量最多,占31.3%,是近5年的研究热点;其次是煤中矿物质、微量元素与地球化学和煤系气方向;预测未来煤炭洁净化利用方向的研究将逐渐增多,与煤地质学相关的交叉学科也将快速发展。
基金The National Natural Science Foundation of China(No.62261032)the Central Government Guiding Funds for Local Scienceand Technology Development Program(No.25ZYJA026).
文摘Current image inpainting models are primarily designed to achieve a large receptive field(RF)using refinement networks to incorporate different scales.However,these models fail to adapt the use of different RFs to the specific patterns of image damage,resulting in artifacts and semantic information confusion in repaired images.To address the problems of artifacts and semantic information confusion,inspired by different sensitivities of different RFs to inpainting the same image damaged patterns,this study proposes an image inpainting method based on multiple receptive fields(MRFs)and dynamic matching of damaged patterns.First,the parallel filter banks are used to extract the MRF feature groups.Second,the features are dynamically weighted and screened,guided by the mask image,to construct a relationship that adaptively matches the most relevant RF to each specific damaged pattern.A fast Fourier convolution based decoder is used to enhance the fusion of global contextual features during the reconstruction of high dimensional features into low dimensional images.Comparative experimental results show that the proposed method achieves better subjective and objective inpainting results on three public datasets:Paris StreetView,CelebA-HQ,and Places2.
基金supported by the National Natural Science Foundation of China (Grant Nos.62274058,62104065)the Open Project of China-Poland Belt and Road Joint Laboratory of Measurement and Control Technology (Grant No.MCT202104)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDB44000000)the Hubei Province Key Research and Development Program (Grant No.2022BAA020)the Wuhan Key Research and Development Program (Grant Nos.2022012202015055,2023010402010612)。
文摘As a key building block of the biological cortex,synapses are powerful information processing units that enable highly complex nonlinear computations.The realization of artificial synapses with similar capabilities has important implications for building intelligent,neuromorphic systems.Here,we demonstrate an artificial synapse based on NbO_(x) nonvolatile memristor to mimic multifunctional bionic applications such as nociceptor and associative learning.Combined experimental characterization with COMSOL simulation,the traditional resistance switching characteristics,which are the decisive factor for the synapse properties are in-depth analyzed.It can be proposed that the I-V characteristics of Pt/NbO_(x)/TiN memristor are governed by core-shell filaments consisting of the shell region of sub-stoichiometric Nb_(2)O_(5-δ)and the core of NbO_(2).On the basis of the core-shell filament model,it can be reasonably explained that Ohmic conduction and Poole-Frenkel conduction take turns to dominate the current flowing in the memristive device,leading to the zigzag evolution of current during the operation process of NbO_(x)-based device.The simulations of synaptic plasticity,including long-term potentiation/depression(LTP/LTD),paired-pulse facilitation(PPF),and spike-timing-dependent plasticity(STDP),exhibiting that the NbO_(x) can be utilized for an artificial synapse.Furthermore,bionic functions such as hyperalgesia and allodynia of a nociceptor and a series of associative learning behaviors in Pavlovian dog experiment are mimicked,illustrating that the Pt/NbO_(x)/TiN have great potential for highly simplified artificial neural network applications.
