检索结果-南通市图书馆

基于循环神经网络模型的无人机音频信号识别算法研究

在线全文

学校读者我要写书评

暂无评论

电声技术 2024年第5期48卷 58-63页

作者：吴晶晶罗志豪李伟赵慎湖南工商大学智能工程与智能制造学院湖南长沙410205

近年来,无人机的广泛应用引发诸多隐私和安全问题。针对此问题,研究基于循环神经网络(Recurrent Neural Network,RNN)模型的无人机音频信号识别算法。首先,对于无人机的音频信号进行特征值提取,基于设计的RNN模型,设置3层长短期记忆网络... 详细信息

近年来,无人机的广泛应用引发诸多隐私和安全问题。针对此问题,研究基于循环神经网络(Recurrent Neural Network,RNN)模型的无人机音频信号识别算法。首先,对于无人机的音频信号进行特征值提取,基于设计的RNN模型,设置3层长短期记忆网络(Long Short-Term Memory,LSTM)和3层Dropout。其次,在输出层使用Softmax作为激活函数输出结果,并在实验过程中不断更新神经元和Dropout的参数。最后,基于实际采集的音频数据进行无人机检测。实验结果表明,所提出算法的准确率达到96.33%,能够满足无人机检测的实际需求。

关键词：无人机音频识别特征提取循环神经网络(RNN)

基于mtDNA Cytb基因对甘肃4个马群体遗传多样性和系统发育的研究

在线全文

学校读者我要写书评

暂无评论

黑龙江畜牧兽医 2024年第12期 41-49,123,124页

作者：高颖成述儒史金平罗志皓张全伟王建福刘哲张勇刘婷甘肃农业大学动物科学技术学院兰州730030

为了研究甘肃境内部分马群体的遗传多样性、遗传结构和母系起源,试验采用DNA测序技术对甘肃4个马群体(岔口驿马49匹、河曲马20匹、山丹马30匹和肃南马34匹)共133个个体血样的线粒体DNA(mitochondrial DNA,mtDNA)中的细胞色素b(cytochrom... 详细信息

为了研究甘肃境内部分马群体的遗传多样性、遗传结构和母系起源,试验采用DNA测序技术对甘肃4个马群体(岔口驿马49匹、河曲马20匹、山丹马30匹和肃南马34匹)共133个个体血样的线粒体DNA(mitochondrial DNA,mtDNA)中的细胞色素b(cytochrome b,Cytb)基因进行PCR扩增,并对4个马群体的Cytb基因序列特征、遗传多样性、遗传距离、遗传分化与变异进行了分析,结合其他马群体的Cytb基因序列构建了系统发育树单位型网络关系图。结果表明:4个马群体Cytb基因序列全长1140 bp,A+T含量(54.6%)大于G+C含量(45.4%),共检测到46个多态位点,33种单倍型;总单倍型多样度为0.9332±0.0100,总核苷酸多样度为0.00385±0.00017,总平均核苷酸差异为4.3714,平均Tajima's D值和Fu's Fs值分别为-1.0352和-13.057;4个马群体间的遗传距离、遗传变异系数和基因流的范围分别为0.0035~0.0042,0.01923~0.09132,4.975~25.504;4个马群体内的遗传变异(94.54%)远大于其群体间的遗传变异(5.46%);4个马群体的33种单倍型分散于6个支系(A~F)中。说明甘肃4个马群体间亲缘关系较近,都具有较高的遗传多样性且均为多母系起源。

关键词：马线粒体DNA(mtDNA) 细胞色素b(Cytb)基因遗传多样性系统发育

An improved algorithm based on equivalent sound velocity profile method at large incident angle

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第2期43卷 161-167页

作者： Qianqian Li Qian Tong Fanlin Yang Qi Li zhihao Juan Yu luo College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao 266590China College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China

With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing *** classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam ***,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge *** analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial ***,an error correction algorithm based on polynomial fitting is *** simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.

关键词： equivalent sound speed profile ray tracing method large incident angle edge beam deep sea error correction multibeam echo-sounder system

∼2.5 nm pores in carbon-based cathode promise better zinc-iodine batteries

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 471-476页

作者： Yajun Hou Chuanzheng Zhu Qiang Wang Xiaomeng Zhao Kun luo Zongshuai Gong zhihao Yuan School of Materials Science and Engineering Tianjin Key Laboratory of Photoelectric Materials&DevicesTianjin University of TechnologyTianjin 300384China

The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I_(2) batteries,but is unclear,retarding further *** work innovatively indicates a great contribution of∼2.5nm pore structure of nanocarbons to efficient iodine adsorption,rapid I^(−)↔I_(2) conversion,and polyiodide inhibition,via scrupulously designing catalysts with controllable pore sizes *** I_(2)-loading within the designed nitrogen-doped nanocarbons can reach up to as high as 60.8 wt%.The batteries based on the cathode deliver impressive performances with a large capacity of 178.8 mAh/g and long-term cycling stability more than 4000 h at 5.0 ***,these is no polyiodide such as I_(3)−and I_(5)−detected during the charge-discharge processes from comprehensive electrochemical cyclic voltammetry,X-ray photoelectron spectroscopy,and Raman *** work provides a novel knowledge-guided concept for rational pore design,promising better Zn-I_(2) batteries,which is also hoped to benefit other advanced energy technologies,such as Li-S,Li-ion,and Al-I_(2) batteries.

关键词： Zinc-iodine batteries Structure-performance relationship Iodine conversion chemistry Cathode materials Porous carbon

Primary Frequency Control Ability Evaluation of Valve Opening in Thermal Power Units Based on Artificial Neural Network

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2020年第3期29卷 576-586页

作者： LIAO Jinlong luo zhihao YIN Feng CHEN Bo SHENG Deren LI Wei YU Zitao Institute of Thermal Science and Power Systems Zhejiang UniversityHangzhou 310027China Electric Power Research Institute of State Grid Zhejiang Electric Power Co.Ltd Hangzhou 310027China

With the development of new energy,the primary frequency control(PFC)is becoming more and more important and *** improve the reliability of the PFC,an evaluation method of primary frequency control ability(PFCA)was ***,based on the coupling model of the coordinated control system(CCS)and digital electro-hydraulic control system(DEH),principle and control mode of the PFC were introduced in *** simulation results showed that the PFC of the CCS and DEH was the most effective control ***,the analysis of the CCS model and variable condition revealed the internal relationship among main steam pressure,valve opening and *** term of this,the radial basis function(RBF)neural network was established to estimate the *** the simulation curves fit well with the actual curves,the accuracy of the coupling model was *** this basis,simulation data was produced by coupling model to verify the proposed evaluation *** low predication error of main steam pressure,power and the PFCA indicated that the method was *** addition,the actual data obtained from historical operation data were used to estimate the PFCA accurately,which was the strongest evidence for this method.

关键词： primary frequency control valve opening main steam pressure thermal power unit artificial neural network evaluation

Direct Regeneration of Spent Lithium-Ion Battery Cathodes:From Theoretical Study to Production Practice

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第10期16卷 304-336页

作者： Meiting Huang Mei Wang Liming Yang zhihao Wang Haoxuan Yu Kechun Chen Fei Han Liang Chen Chenxi Xu Lihua Wang Penghui Shao Xubiao luo National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization Nanchang Hangkong UniversityNanchang 330063People's Republic of China Key Laboratory of Hunan Province for Advanced Carbon-based Functional Materials School of Chemistry and Chemical EngineeringHunan Institute of Science and TechnologyYueyang 414006People's Republic of China College of Materials Science and Engineering Central South University of Forestry and TechnologyChangsha 410004People's Republic of China School of Life Science Jinggangshan UniversityJi'an 343009People's Republic of China

Direct regeneration method has been widely concerned by researchers in the field of battery recycling because of its advantages of in situ regeneration,short process and less pollutant *** this review,we firstly analyze the primary causes for the failure of three representative battery cathodes(lithium iron phosphate,layered lithium transition metal oxide and lithium cobalt oxide),targeting at illustrating their underlying regeneration mecha-nism and *** stripping of material from the collector to obtain pure cathode material has become a first challenge in recycling,for which we report several pretreatment methods currently available for subsequent regeneration *** review and discuss emphatically the research progress of five direct regeneration methods,including solid-state sintering,hydrothermal,eutectic molten salt,electrochemical and chemical lithiation ***,the application of direct regeneration technology in production practice is introduced,the problems exposed at the early stage of the industrialization of direct regeneration technol-ogy are revealed,and the prospect of future large-scale commercial production is *** is hoped that this review will give readers a comprehensive and basic understanding of direct regeneration methods for used lithium-ion batteries and promote the industrial application of direct regeneration technology.

关键词： Spent LIBs Failure reasons Cathode recycling Direct regeneration Production practice

A lightweight semantic segmentation algorithm integrating CA and ECA Net modules

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年

作者： Guo zhihao Ma Dongmei luo Xiaoyun School of Physics and Electronic Engineering Northwest Normal University

Aiming at the existing semantic segmentation process due to the loss of pixel features and the complexity of calculating too many parameters， which leads to unsatisfactory segmentation results and too long time， this paper proposes a lightweight semantic segmentation algorithm based on the fusion of multiple modules. The algorithm is based on the PSPNet network， firstly， MobileNetV2 network is chosen as the feature extraction network to construct the lightweight network structure; in the training of the network， a freeze and thaw method is used， and the Focal Loss loss function is added to balance the proportion of positive and negative samples; after that， spatial and channel reconstruction convolution SCConv is introduced in the pyramid pooling module to reduce the segmentation task. The computational cost due to redundant feature extraction is reduced; finally， the coordinate attention mechanism CA and the convolutional attention mechanism ECA-Net are incorporated to make the multi-modules integrate with each other to enhance the salient features and improve the segmentation accuracy. Through the ablation and comparison experiments， the average pixel accuracy on PASCAL VOC 2012 dataset reaches 85.23%， the computation amount is reduced by 45.79%， and the training speed is improved by 68.69%; the average pixel accuracy on Cityscapes dataset reaches 86.75%， and the average intersection and merger ratio reaches 73.86%，and the interaction of multiple modules with correlation performance makes the algorithm is improved and optimised， effectively solving the problems of low segmentation accuracy and slow training speed in the algorithm， which has a significant accuracy advantage in the lightweight model， and can generally improve the efficiency of image semantic segmentation.

关键词：

Photobiomodulation inhibits the expression of chondroitin sulfate proteoglycans after spinal cord injury via the Sox9 pathway

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第1期19卷 180-189页

作者： zhihao Zhang Zhiwen Song Liang luo Zhijie Zhu Xiaoshuang Zuo Cheng Ju Xuankang Wang Yangguang Ma Tingyu Wu Zhou Yao Jie Zhou Beiyu Chen Tan Ding Zhe Wang Xueyu Hu Department of Orthopedics Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina

Both glial cells and glia scar greatly affect the development of spinal cord injury and have become hot spots in research on spinal cord injury *** cellular deposition of dense extracellular matrix proteins such as chondroitin sulfate proteoglycans inside and around the glial scar is known to affect axonal growth and be a major obstacle to autogenous *** proteins are thus candidate targets for spinal cord injury *** previous studies demonstrated that 810 nm photo biomodulation inhibited the formation of chondroitin sulfate proteoglycans after spinal cord injury and greatly improved motor function in model ***,the specific mechanism and potential targets involved remain to be *** this study,to investigate the therapeutic effect of photo biomodulation,we established a mouse model of spinal cord injury by T9 clamping and irradiated the injury site at a power density of 50 mW/cm~2 for 50 minutes once a day for 7 consecutive *** found that photobiomodulation greatly restored motor function in mice and down regulated chondroitin sulfate proteoglycan expression in the injured spinal *** analysis revealed that photobiomodulation inhibited the expression of proteoglycan-related genes induced by spinal cord injury,and versican,a type of proteoglycan,was one of the most markedly changed *** staining showed that after spinal cord injury,versican was present in astrocytes in spinal cord *** expression of versican in primary astrocytes cultured in vitro increased after inflammation induction,whereas photobiomodulation inhibited the expression of ve ***,we found that the increased levels of p-Smad3,p-P38 and p-Erk in inflammatory astrocytes were reduced after photobiomodulation treatment and after delivery of inhibitors including FR 180204,(E)-SIS3,and SB *** suggests that Sma d 3/Sox9 and MAP K/Sox9 pathways may be involved in the effects of photobiomodulatio

关键词： chondroitin sulfate proteoglycans Erk MAPK P38 photobiomodulation principal component analysis Smad3 Sox9 spinal cord injury versican

Rice melatonin deficiency causes premature leaf senescence via DNA methylation regulation

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2024年第3期12卷 721-731页

作者： Yue Lu Ahmed Gharib Rujia Chen Hanyao Wang Tianyun Tao zhihao Zuo Qing Bu Yanze Su Yaoqing Li Yanmo luo Hamdi F.El-Mowafi Zhichao Wang Qianfeng Huang Shuting Wang Yang Xu Pengcheng Li Chenwu Xu Zefeng Yang Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education Agriculture College of Yangzhou UniversityYangzhou 225009JiangsuChina Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops Jiangsu Key Laboratory of Crop Genetics and PhysiologyYangzhou UniversityYangzhou 225009JiangsuChina National Institute of Laser Enhanced Sciences(NILES) Cairo UniversityGiza 12613Egypt Rice Research Department Field Crops Research InstituteAgricultural Research CenterSakhaKafr El-Sheikh 33717Egypt

In a study of DNA methylation changes in melatonin-deficient rice mutants,mutant plants showed premature leaf senescence during grain-filling and reduced grain *** deficiency led to transcriptional reprogramming,especially of genes involved in chlorophyll and carbon metabolism,redox regulation,and transcriptional regulation,during dark-induced leaf *** of mCG and mCHG in the melatonin-deficient rice mutants was associated with the expression change of both protein-coding genes and transposable element-related *** in gene expression and DNA methylation in the melatonin-deficient mutants were compensated by exogenous application of melatonin.A decreased S-adenosyl-L-methionine level may have contributed to the DNA methylation variations in rice mutants of melatonin deficiency under dark conditions.

关键词： Melatonin Premature leaf senescence Rice DNA methylation Epigenetic regulation