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A first-principles study of the size-dependent electronic properties of SiC nanotubes

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Science China(Physics,Mechanics & Astronomy) 2010年第7期53卷 1333-1338页

作者： zhang WeiHu zhang fuchun zhang ZhiYong LU ShuYuan YANG YanNing Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710068China Graduate University of Chinese Academy of Sciences Beijing 100049China College of Physics and Electronic Information Yan’an UniversityYan’an 716000China College of Information Science and Technology Northwest UniversityXi’an 710127China Department of Telecommunications Xi’an Institute of Posts and TelecommunicationsXi’an 710121China

We investigate the structural and electronic properties of SiC nanotubes(NTs) with hexagonal cross sections by a first-principles calculation using plane-wave ultra-soft pseudo-potential technology based on the density-functional theory.Our results reveal that surface-layer C and Si atoms relax significantly upon decreasing the tube-wall thickness because of surface-size and quantum-size effects.We also find that all relaxed SiC NTs stay stably on the nanoscale because of an admixture of sp2 and sp3 hybridization between C and Si atoms and a strong covalent,and that the band gap tends to decrease with increasing tube-wall thickness.Our calculations further indicate that both C and Si atoms on the inner and outer surface of SiC NTs contribute to defect states at the top of the valence band and at the bottom of the conduction band.These results provide reference information for a thorough understanding of the properties of SiC nanostructures and also enable more precise monitoring and control of the growth of SiC nanostructures.

关键词： density function theory SiC nanotube electronic properties quantum-size effects

The Motion Planets Detection and Tracking Algorithm Based on Gestalt Principle

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Chinese Journal of Electronics 2018年第4期27卷 808-812页

作者： QIU Shi TANG Ying zhang Wenbo FENG Jun zhang fuchun LI Chen Xi'an Institute of Optics and Precision Mechanics of CAS Chengdu University of Technology College of Information Science & Technology School of Electronic Engineering Xidian University School of Information Science and Technology Engineering Northwestern University Department of Aviation Theory Aviation University of Air Force Institute of Deep-sea Science and Engineering Chinese Academy of Sciences

The moving planets have a few of pixels which can lead to lacking enough image characteristics when tracking them. So we propose the motion planets detection and tracking algorithm based on gestalt principle. We structure Gaussian mixture model to detect the motion area from the visual cognition perspective, and use astronomy images graphics characteristics to confirm the planet position. Then we propose space-time fusion model for tracking planet. All the experiments use 1000 16-bitframe images of wide view CCD camera which contain 5684 motion planets in total. The results show that our algorithm reaches an accuracy of 94% and has robustness.

关键词： The moving planets Gestalt principle Tracking

基于KL散度工况识别的混合动力汽车队列的分层控制

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汽车安全与节能学报 2024年第2期15卷 242-252页

作者：尹燕莉王福振詹森黄学江张鑫新张富椿重庆交通大学机电与车辆工程学院重庆400074

针对混合动力汽车队列行驶过程中工况的适应性问题,提出了一种基于KL(Kullback-Leibler)散度工况识别的分层控制方法。上层控制器利用车—车通信技术,获取队列中前车状态信息,采用模型预测控制(MPC)算法,实现队列纵向控制,并计算出最优... 详细信息

针对混合动力汽车队列行驶过程中工况的适应性问题,提出了一种基于KL(Kullback-Leibler)散度工况识别的分层控制方法。上层控制器利用车—车通信技术,获取队列中前车状态信息,采用模型预测控制(MPC)算法,实现队列纵向控制,并计算出最优跟车车速;下层控制器基于典型工况,离线求解需求功率的转移概率矩阵,并通过Q-Learning算法训练最优Q表嵌入整车模型中;在行驶中以固定时间长度在线更新转移概率矩阵,采用KL散度进行工况识别,根据识别的工况类型,结合当前时刻车速、需求功率和电池荷电状态(SOC),通过在线查表实现转矩分配。结果表明:与未考虑工况识别策略相比,本策略的油耗降低了8.6%;与作为基准的动态规划(DP)相比,增加了4.8%;在与DP油耗基本保持相同的前提下,该策略离线仿真时间缩短21%,不仅能够在线应用,还能实时适应工况变化。

关键词：混合动力汽车汽车队列工况识别模型预测控制(MPC)算法 Q-Learning算法 KL(Kullback-Leibler)散度

Efficacy and safety of Mianyi granules(免疫Ⅱ颗粒) for reversal of immune nonresponse following antiretroviral therapy of human immunodeficiency virus-1:a randomized,double-blind,multi-center,placebo-controlled trial

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Journal of Traditional Chinese Medicine 2022年第3期42卷 432-438页

作者： LIU Ying ZOU Wen XIAN Qingfei DENG Xin zhang fuchun WANG Li LI Yonghong LUN Wenhui WANG Jian Traditional Chinese Medicine Center for Acquired Immune Deficiency Syndrome Prevention and Treatment China Academy of Chinese Medical SciencesBeijing 100700China Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine Nanning 530011China Infectious Disease Department of Guangzhou Eighth People’s Hospital Guangzhou 510060China Internal Medicine Department of Traditional Chinese Medicine Yunnan Provincial Academy of Traditional Chinese MedicineKunming 650031China Department of Hepatology Shenyang Sixth People’s HospitalShenyang 110006China Department of Dermatology Beijing Ditan HospitalBeijing 100015China

OBJECTIVE:To investigate whether Mianyi granules(免疫Ⅱ颗粒)are effective and safe in reversing immune nonresponse following antiretroviral therapy(ART)in individuals with human immunodeficiency virus(HIV)infection.METHODS:Randomized,double-blind,multi-center,placebo-controlled trial(factorial design)of daily oral Mianyi granules versus placebo for 72 weeks.A total of 361 HIV-positive individuals receiving ART at five ClassⅢGradeⅠhospitals in China between September 2013 and January 2016 completed the study.The primary endpoints were frequencies of CD3+,CD4+,CD8+,and CD45 RA+cells at seven timepoints over the 72 weeks.Secondary endpoints included viral loads,clinical symptoms,and quality of life at 72 weeks.RESULTS:A total of 400 participants were enrolled in the study and randomized,of whom 361 completed the study:189 individuals(140 men and 49 women)in the Mianyi granule group and 172 individuals(135 men and 37 women)in the placebo group.In the intent-to-treat population,CD4+T cell counts increased from(193±71)cells/mm^(3)at baseline to(288±131)cells/mm^(3)posttreatment in the Mianyi granule group and from(200±75)cells/mm^(3)at baseline to(264±124)cells/mm^(3)posttreatment in the placebo group.Patients treated with Mianyi granule had higher increases in CD4+T cell counts than those treated with placebo(P=0.045).Reversal of immune nonresponse was defined as a CD4+T cell increase of more than 100 cells/mm^(3).After treatment for 72 weeks,Mianyi granule was effective in reversing immune nonresponse in a higher proportion of individuals(20.2%)compared with placebo(9.7%).CD45 RA+cell counts increased from(34±32)cell/mm^(3)at baseline to(51±61)cells/mm^(3)post-treatment in the Mianyi granule group and from(37±33)cells/mm^(3)at baseline to(48±37)cells/mm^(3)post-treatment in the placebo group.Mianyi granules were more effective than placebo in increasing CD45 RA+cell counts.CONCLUSIONS:In ART-treated HIV-positive adults with immune nonresponse,treatment with Mianyi granules for 72 weeks was safe and significantly increased

关键词： HIV-1 immunity antiretroviral therapy treatment outcome safety Mianyi granules

社保缴费与小微企业产品技术创新关系研究——基于CMES数据调查的实证分析

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中国物价 2024年第6期 58-62页

作者：张海峰张福春中共江门市委党校经济教研室中共海南省委党校经济教研部

本文基于中国小微企业调查数据,实证分析社保缴费对小微企业产品技术创新的影响。结果表明:(1)社保缴费能够促进小微企业的产品技术创新,社保缴费规模越大,小微企业的产品技术创新程度越高;(2)社保缴费对小微企业产品技术创新的作用存... 详细信息

本文基于中国小微企业调查数据,实证分析社保缴费对小微企业产品技术创新的影响。结果表明:(1)社保缴费能够促进小微企业的产品技术创新,社保缴费规模越大,小微企业的产品技术创新程度越高;(2)社保缴费对小微企业产品技术创新的作用存在地区差异,对东部地区小微企业的产品技术创新作用显著,对中西部地区的小微企业作用不显著;(3)社保缴费与规模对产品技术创新的作用存在企业主学历差异,企业主学历为低学历组的小微企业,社保缴费与规模对产品技术创新的作用显著,高学历组作用不显著。

关键词：社保缴费小微企业产品技术创新 CMES

Computational exploration and screening of novel Janus MA2Z4 (M = Sc–Zn, Y–Ag, Hf–Au;A=Si, Ge;Z=N, P) monolayers and potential application as a photocatalyst

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Frontiers of physics 2022年第6期17卷 51-61页

作者： Weibin zhang Woochul Yang Yingkai Liu Zhiyong Liu fuchun zhang College of Physics and Electronics Information Yunnan Key Laboratory of Opto-Electronic Information TechnologyKey Laboratory of Advanced Technique&Preparation for Renewable Energy Materials-Ministry of EducationYunnan Normal UniversityKunming 650500China College of Physics and Electronic Information Yan’an UniversityYan’an 716000China Department of Physics Dongguk UniversitySeoul 04620Republic of Korea

By high-throughput calculations,13 thermally and environmentally stable Janus MA_(2)Z_(4) monolayers were screened from 104 types of candidates.The 13 stable monolayers have very high charge carrier concentrations(×10^(15) cm^(–2)),which are better than those of the well-known graphene and TaS_(2).Because of their excellent conductivity,the 6 monolayers with band gaps less than 0.5 eV are identified as potential electrode materials for hydrogen evolution reaction applications.For potential applications as photoelectric or photocatalytic materials,bandgaps(Eg-HSE)higher than 0.5 eV remained,which resulted in 7 potential candidates.Based on optical absorption analysis in the visible-light range,H-HfSiGeP_(4) and HMoSiGeP_(4) have higher absorption ability and optical conductivity,which is quite impressive for optoelectronic,solar cell device,and photocatalysis applications.Additionally,the transmittance coefficient of Janus MA_(2)Z_(4) monolayers is approximately 70%–80%in the visible-light range,which implies that these monolayers show good light transmittance.For potential applications as photocatalysts,the redox potential and charge effective mass analysis indicate that H-HfSiGeP_(4),HMoSiGeP_(4),T-ScSiGeN_(4),and T-ZrSiGeN_(4) are suitable photocatalysts for CO_(2) reduction reactions.Using high-throughput identification,13 types of new and stable Janus MA2Z4 monolayers were explored,and the basic properties and potential applications were investigated,which can reduce the time for experiments and provide basic data for the material genome initiative.

关键词： Janus MA2Z4 high-throughput identification charge carrier concentration electronic structure optical properties

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基于YOLOv7的交通目标检测算法研究

计算机测量与控制 2024年第4期32卷 74-80页

作者：王沛雪张富春董晨乐延安大学物理与电子信息学院陕西延安716000

针对交通场景中,由于光照、遮挡、目标小以及背景复杂等因素导致目标检测精度低,易出现漏检和误检问题的情况,提出了一种基于YOLOv7的交通目标检测算法;该算法在主干网络中融入多头注意力机制,以增强网络特征学习能力,从而更好地捕获数... 详细信息

针对交通场景中,由于光照、遮挡、目标小以及背景复杂等因素导致目标检测精度低,易出现漏检和误检问题的情况,提出了一种基于YOLOv7的交通目标检测算法;该算法在主干网络中融入多头注意力机制,以增强网络特征学习能力,从而更好地捕获数据和特征内部的相关性;在YOLOv7颈部网络引入协调注意力模块(CA),将位置信息嵌入到注意力机制中,忽略无关信息的干扰,以增强网络的特征提取能力;增加一个多尺度检测网络,以增强模型对不同尺度目标的检测能力;将CIoU损失函数更改为SIoU函数,以减少模型收敛不稳定问题,提高模型的鲁棒性;实验结果表明,改进的算法在BDD100K公开数据集上的检测精度和速度分别达到了59.8%mAP和96.2 FPS,相比原算法检测精度提高了2.5%;这表明改进的算法在满足实时性要求的同时,具备良好的检测精度,适用于复杂情况下的交通目标检测任务。

关键词：交通目标检测 YOLOv7网络注意力机制浅层网络检测层 SIoU损失函数

153例急性期和慢性期布鲁氏菌病患者临床表现、实验室特征及治疗比较

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中华地方病学杂志 2024年第5期43卷 398-403页

作者：杨慧勤郑海鹏陈旭丹谭颖张复春李凌华王建广州医科大学附属市八医院感染病中心广州

目的了解急性期和慢性期布鲁氏菌病(简称布病)患者的临床表现、实验室特征及治疗情况。方法回顾性收集2012 - 2022年广州医科大学附属市八医院收治的153例布病患者临床资料, 包括一般资料、流行病学特征、临床表现、实验室检查结果、影... 详细信息

目的了解急性期和慢性期布鲁氏菌病(简称布病)患者的临床表现、实验室特征及治疗情况。方法回顾性收集2012 - 2022年广州医科大学附属市八医院收治的153例布病患者临床资料, 包括一般资料、流行病学特征、临床表现、实验室检查结果、影像学检查结果、治疗及预后情况。按病程< 180 d和≥180 d分为急性期组和慢性期组, 对比分析两组患者临床资料。结果共纳入布病患者153例, 其中急性期组119例、慢性期组34例。年龄为(46.2 ± 13.8)岁, 男性115例(75.2%)、女性38例(24.8%), 85例(55.6%)患者为职业接触。90例(58.8%)患者出现并发症, 慢性期组并发症发生率高于急性期组[76.5%(26/34)比53.8%(64/119), χ2 = 5.62, P = 0.018]。临床表现主要为发热和关节痛, 分别有128例(83.7%)和124例(81.0%)。急性期组发热发生率高于慢性期组[87.4%(104/119)比70.6%(24/34), χ2 = 5.46, P = 0.019], 而关节痛发生率低于慢性期组[77.3%(92/119)比94.1%(32/34), χ2 = 4.83, P = 0.027]。实验室检查中, 血培养阳性率为59.5%(91/153), 急性期组血培养阳性率高于慢性期组[67.2%(80/119)比32.4%(11/34), P < 0.05];急性期组降钙素原(PCT)升高发生率[58.6%(58/99)比24.1%(7/29), χ2 = 10.65, P = 0.001]和肝功能异常发生率均高于慢性期组[33.9%(40/118)比15.2%(5/33), χ2 = 4.33, P = 0.037]。影像学检查中, 61例(39.9%)患者发生骨质破坏, 慢性期组骨质破坏发生率高于急性期组[55.9%(19/34)比35.3%(42/119), χ2 = 4.68, P = 0.031]。所有患者均使用抗生素治疗, 急性期、慢性期组使用抗生素种类的中位数分别为3、4种。总体药物不良反应发生率为5.2%(8/153), 治疗后65例(42.5%)痊愈、70例(45.8%)好转、18例(11.8%)未愈。结论布病患者的主要临床表现为发热和关节痛, 并发症发生率较高, 均采用联合抗感染治疗。急性期患者发热、血培养阳性、PCT升高、肝功能异常发生率较高, 慢性期患者并发症、关节痛、骨质破坏发生率较高。

关键词：布鲁氏菌病临床表现实验室特征治疗

HetNets Under Decoupled Uplink and Downlink Access with UE Random Discontinuous Transmission: Local Delay and Energy Efficiency

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China Communications 2024年第3期21卷 205-216页

作者： zhang Yue Zheng fuchun Luo Jingjing School of Electronic and Information Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Due to the limited uplink capability in heterogeneousnetworks (HetNets), the decoupled uplinkand downlink access (DUDA) mode has recently beenproposed to improve the uplink performance. In thispaper, the random discontinuous transmission (DTX)at user equipment (UE) is adopted to reduce the interferencecorrelation across different time slots. By utilizingstochastic geometry, we analytically derive themean local delay and energy efficiency (EE) of an uplinkHetNet with UE random DTX scheme under theDUDA mode. These expressions are further approximatedas closed forms under reasonable assumptions.Our results reveal that under the DUDA mode, there isan optimal EE with respect to mute probability underthe finite local delay constraint. In addition, with thesame finite mean local delay as under the coupled uplinkand downlink access (CUDA) mode, the HetNetsunder the DUDA mode can achieve a higher EE witha lower mute probability.

关键词： decoupled uplink and downlink access(DUDA) heterogeneous networks(HetNets) random discontinuous transmission(DTX) stochastic geometry