基于改进的HMAX算法的车型识别应用

本文实现了将改进的HMAX算法应用于车型识别领域。算法的主要创新点是采用ITTI显著性算法选取车辆图片显著点构造图库,通过采用对颜色、亮度和朝向三方面敏感度的综合,构造更具代表性的模板库,提高了算法的识别率。此外,通过计算同一模板与不同图片响应度值的方差,消除了冗余模板,降低了算法识别时间。分析和实验表明,改进的HMAX算法可以有效地实现车型识别,新提出的算法相对原先HMAX模型在识别率可以提高1%~2%,相对当前存在的其他车型识别算法在识别率方面可提升约5%~10%,在保证特征数量的前提下,识别率接近95%;此外,加入模版筛选方法的改进算法相对于原先HMAX模型在识别率基本保持不变的条件下,识别时间可以缩减到原先的1/4,最终根据效益值评估的最优组合中,识别率约为92%,识别时间为0.6s/幅图片,相对于原先方法均达到了一定的提升。

Highly stable Zn anodes realized by 3D zincophilic and hydrophobic interphase buffer layer

Aqueous zinc-ion batteries(AZIBs)are promising contenders for energy storage systems owing to their low cost and high safety.However,their practical application is hindered by uncontrolled Zn dendrites and other side reactions.Here,the three-dimensional(3D)TiO2/Cu2Se/C heterostructure layer derived from MXene/Cu-MOF is constructed on the Zn anode to control the deposition/dissolution behavior,which has numerous active sites,better electrical conductivity and excellent structural stability.Based on DFT calculation,the built-in electric field(BIEF)formed of TiO2/Cu2Se/C can enhance charge transfer and ionic diffusion to inhibit the dendrites.Furthermore,hydrophobic coating has the ability to impede the corrosion and hydrogen evolution reaction(HER)of zinc anode.Thus,TiO2/Cu2Se/C@Zn enable the stable and reversible Zn plating/stripping process with the outstanding lifetime of 1100 h at 2 mA·cm^(-2) and even 650 h at 10 mA·cm^(-2).The batteries constructed with commercial MnO2 cathodes demonstrate the remarkable capacity(248.7 mAh·g−1 at 0.1 A·g−1)and impressive cycle stability(with 71.3%capacity retention after 300 cycles).As well as extending the life of AZIBs,this study is also motivating for other metal anode based secondary batteries.

MOF-derived Se doped MnS/Ti_(3)C_(2)T_(x) as cathode and Zn-Ti_(3)C_(2)T_(x) membrane as anode for rocking-chair zinc-ion battery

Mn-based zinc ion battery has the advantages of low cost and high performance,which makes it the promising energy storage system.However,the poor conductivity and the agglomeration in the synthesis process of manganese-based materials restrict the performance of batteries.Herein,the Se-doped MnS/Ti_(3)C_(2)T_(x)(Se-MnS/Ti_(3)C_(2)T_(x))composite material derived from Mn-based metal-organic framework is reported.Electrochemical tests show that Se-doped could generate S defects and enhance the electrochemical activity of MnS.At the same time,the introduction of Ti_(3)C_(2)T_(x) substrate is conducive to exposing more sulfur defects and improving the utilization rate of defects.In the mechanism study,it is found that Se-MnS/Ti_(3)C_(2)T_(x) is transformed into S/Se co-doped Mn3O_(4) at the first charge,which innovatively elucidated the behavior of S/Se during activation.In the electrochemical performance test,the specific capacity can reach 74.7 mAh·g^(-1) at 5.0 A·g^(-1).In addition,the Zn-Ti_(3)C_(2)T_(x) membrane electrode is prepared by vacuum filtration as the zinc-poor anode,which is assembled into the rocking chair full battery to avoid dendrite growth and exhibit excellent rate performance.The addition of Zn2+weakens the electrostatic repulsion between the interlayers of MXene,and the formation of the folded morphology aids the penetration of the electrolyte.At 1.0 A·g^(-1),the capacity can reach 50.6 mAh·g^(-1).This work is helpful to promote the research and development of the reaction mechanism of manganese based rocking chair batteries.

Finite Groups with Some Bounded Codegrees

For a characterχof a finite group G,the number cod(χ) := ∣G:ker(χ)∣/χ(1)is called the codegree ofχ.In this paper,we give a solvability criterion for a finite group G depending on the minimum of the ratioχ(1)^(2)/cod(χ),whenχvaries among the irreducible characters of G.

A COVID-19 case report from asymptomatic contact:implication for contact isolation and incubation management

Background:As of 2 March,2020,at least 80151 coronavirus disease 2019(COVID-19)cases were reported in China.Most of the patients had a history of visiting Hubei Province or contacting with people who had ever stayed in or passed by Hubei Province or were exposed to symptoms.Some patients got infected through only asymptomatic contact.This study aimed to report the epidemic features and lab identification of a patient confirmed with COVID-19 infection through only asymptomatic contact.Case presentation:A 44-year-old man,who lived in Nanchang,Jiangxi Province,China until 6 March 2020,suffered from cough on 27 January 2020.Fever symptoms appeared on 28 January,with a maximum temperature of 38.8℃,accompanied by cough,sore throat,headache,fatigue,muscle ache,joint ache,and other symptoms.The symptoms continued until he was hospitalized on 30 January.Coronavirus conventional polymerase chain reaction assay was positive for the throat swab sample.The patient,along with his wife and son,drove from Nanchang to back to Honghu City,Hubei Province,on 23 January 2020.After staying with his parents and brother’s family for 3 days,the patient drove back to Nanchang and arrived on 25 January.On the way back home,they stopped by Tongshan service area,Hubei Province,without any close contact with other people.After arriving home in Nanchang City,Jiangxi Province,none of them left their residence.In addition,his parents stayed at home for 20 days with his younger brother’s family before they got back.His younger brother and one of his brother’s children visited Wuhan on 5 January and came home on 6 January 2020.Conclusions:This report suggested that,in the early phase of COVID-19 pneumonia,routine screening could miss patients who were virus carriers.Highlighting travel history is of paramount importance for the early detection and isolation of severe acute respiratory syndrome coronavirus 2 cases.

A Noteof CP_(2) Groups

A new class CP_(2) groups of finite groups was characterized by using an inequality of the orders of elements.In this short paper we give a note of CP_(2) groups since CP_(2) groups is a subclass of CP(EPPO)groups.Moreover,we discuss the struc-ture of finite p groups contained in CP 2 groups.