检索结果-南通市图书馆

Chinese Journal of Aeronautics 2024年第1期37卷 201-217页

作者： Chinan liU Yuan li Yi CHENG An’an ZHAO Kunpeng DU Yue SHI ximing li Hui CHENG School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China AVIC Xi’an Aircraft Industry Group Company LTD Xi’an 710089China

In this paper,the influence of forced installation caused by a hole-location error on the 3D stress distribution and damage of a composite bolted joint is *** analytical model of stress distributed on composite holes is promoted,in view of non-uniform extrusion caused by forced *** first,non-uniform extrusion of the hole edge caused by forced installation is *** to the contact state,expression of hole deformation is ***,based on Hertz theory,the maximum extrusion load is obtained with help of deformation *** constructing an elastic foundation beam model,3D stress distributed on a hole could be analyzed according to the extrusion ***,stress distribution predicted by the above analytical method is compared with that provided by FE considering composite ***,a forced installation experiment is carried out to analyze the damage distribution of the *** show that a central-symmetrically distributed stress is introduced by the hole-location *** an increment of the error,strength of composite decreases due to extrusion ***,stress presents a concave distribution on the *** the hole-location error exceeding 3%,stress decreases gradually due to failure of *** of holes does not exhibit a centrosymmetric *** damage is mainly distributed on the entrance of the hole at the lower sheet.

关键词： Hole-location error Composite joint Forced installation Stress distribution Damage

Broadband intelligent programmable metasurface with polarization-modulated self-adaptive electromagnetic functionality switching

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第7期12卷 1395-1409页

作者： ximing li RUI XU XIAOFENG SUN YUAN ZHAO ZHAO YANG GUOHONG DU College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China

Programmable metasurfaces have received a great deal of attention due to their ability to dynamically manipulate electromagnetic(EM) waves. Despite the rapid growth, most of the existing metasurfaces require manual control to switch among different functionalities, which poses severe limitations on practical applications. Here, we put forth an intelligent metasurface that has self-adaptive EM functionality switching in broadband without human participation. It is equipped with polarization discrimination antennas(PDAs) and feedback components to automatically adjust functionalities for the different incident polarization information.

关键词： equipped adjust polarization

Recent advances in core-shell organic framework-based photocatalysts for energy conversion and environmental remediation

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 168-199,I0004页

作者： Qibing Dong ximing li Yanyan Duan Qingyun Tian Xinxin liang Yiyin Zhu lin Tian Junjun Wang Atif Sial Yongqian Cui Ke Zhao Chuanyi Wang School of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi’an 710021ShaanxiChina Guangdong Engineering Technology Research Center for Environmental Purification and Functional Materials Guangzhou Institute of Industrial IntelligenceGuangzhou 511400GuangdongChina Jiangxi Key Lab of Flexible Electronics Flexible Electronics Innovation InstituteJiangxi Science and Technology Normal UniversityNanchang 330013JiangxiChina Helmholtz-Zentrum Berlin für Materialien und Energie Kekuléstraße 512489 BerlinGermany

Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy *** a variety of materials developed as photocatalysts,the core-shell metal/covalent-organic framework(MOF or COF)photocatalysts have garnered significant attention due to their highly porous structure and the adjustability in both structure and *** existing reviews on core-shell organic framework photocatalytic materials have mainly focused on core-shell MOF ***,there is still a lack of indepth reviews specifically addressing the photocatalytic performance of core-shell COFs and MOFs@***,there is an urgent need for a comprehensive review encompassing these three types of core-shell *** on this,this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable core-shell organic framework photocatalysts towards appropriate photocatalytic energy conversion and environmental ***,the classification,synthesis,formation mechanisms,and reasonable regulation of core-shell organic framework were ***,the photocatalytic applications of these three kinds of core-shell structures in different areas,such as H_(2)evolution,CO_(2)reduction,and pollutants degradation are ***,the main challenges and development prospects of core-shell organic framework photocatalysts were *** review aims to provide insights into the development of a novel generation of efficient and stable core-shell organic framework materials for energy conversion and environmental remediation.

关键词： Organic framework Core-shell structure Photocatalysis Energy conversion Environmental remediation

省级自贸区试点政策对城市经济增长的空间效应

在线全文

学校读者我要写书评

暂无评论

经济地理 2024年第2期44卷 21-30,42页

作者：丁任重李溪铭西南财经大学经济学院四川成都610095 西南财经大学中国西部经济研究院四川成都610095

文章基于2006—2020年我国设立的21个省级自贸区下辖的220个地级及以上城市面板数据,采用空间双重差分计量模型就自贸区试点政策对城市经济增长的影响及其空间溢出效应展开实证研究。结果表明:①自贸区试点政策可以通过拓展开放、创新溢... 详细信息

文章基于2006—2020年我国设立的21个省级自贸区下辖的220个地级及以上城市面板数据,采用空间双重差分计量模型就自贸区试点政策对城市经济增长的影响及其空间溢出效应展开实证研究。结果表明:①自贸区试点政策可以通过拓展开放、创新溢出2条路径促进试点城市经济增长;②拓展开放、创新溢出2种传导路径均具有较强的空间溢出性,体现了自贸区片区城市“由点带面”、拉动省级自贸区全域增长的特征;③自贸区试点政策及其空间溢出的政策效果受到自贸区园区面积的正向影响。据此,提出应继续加大我国自贸区战略的实施力度,优化空间布局,提升创新能力,完善园区建设,共同促进区域经济高质量发展。

关键词：自由贸易区城市经济政策效果自贸区网络空间双重差分模型高水平对外开放区域经济

在线全文

学校读者我要写书评

暂无评论

轴承套圈内圆切入磨早期颤振在线监测方法

振动．测试与诊断 2024年第4期44卷 761-770,830,831页

作者：迟玉伦应晓昂俞鑫李希铭上海理工大学机械工程学院上海200093

为弥补轴承套圈内圆切入磨颤振在早期识别中的特征量选取和智能算法模型方面的不足,提出了基于均方频率和能量熵结合人工蜂群(artifical bee colony,简称ABC)优化支持向量机(support vector machine,简称SVM)的方法。首先,将轴承套圈内... 详细信息

为弥补轴承套圈内圆切入磨颤振在早期识别中的特征量选取和智能算法模型方面的不足,提出了基于均方频率和能量熵结合人工蜂群(artifical bee colony,简称ABC)优化支持向量机(support vector machine,简称SVM)的方法。首先,将轴承套圈内圆切入磨过程中的声发射、振动信号通过提取特征方法,获得能量熵、时域参数、能量占比和均方频率4个特征参数;其次,将4个特征参数两两组成特征向量导入SVM,利用准确度、Kappa系数和混淆矩阵分析结果;最后,将均方频率和能量熵导入不同智能算法进行监测分析。结果表明,均方频率和能量熵组成的特征向量对轴承套圈内圆切入磨早期颤振识别效果最优,同时结合ABC-SVM,识别效果可达100%,为在线监测轴承套圈内圆切入磨早期颤振提供了有效方法。

关键词：轴承套圈内圆切入磨早期颤振均方频率能量熵人工蜂群

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

新质生产力的理论基础、时代逻辑与实践路径

经济纵横 2024年第4期 1-11,F0002页

作者：丁任重李溪铭西南财经大学经济学院四川成都610095 西南财经大学中国西部经济研究院四川成都610095

新质生产力以战略性新兴产业和未来产业为基础,以科技创新突破为关键路径,以“新技术、新产业、新业态”为特征,是一种对传统劳动者、劳动资料及劳动对象产生颠覆性变革的生产力发展模式。从理论基础来看,新质生产力是对马克思主义生产... 详细信息

新质生产力以战略性新兴产业和未来产业为基础,以科技创新突破为关键路径,以“新技术、新产业、新业态”为特征,是一种对传统劳动者、劳动资料及劳动对象产生颠覆性变革的生产力发展模式。从理论基础来看,新质生产力是对马克思主义生产力理论与科技创新理论的继承与创新;从时代逻辑来看,新质生产力是中国式现代化背景下新起点、新要素、新模式与新动能的生产力,是我国生产力发展过程中的重大总结。为此,应通过加速人力资本积累、加强自主创新能力、加快科技成果转化、培育高新技术产业、探索新型举国体制及优化科技政策支持,推进新质生产力持续健康发展。

关键词：新质生产力科技创新高质量发展

脑电双频指数监测下瑞马唑仑在老年患者无痛胃肠镜检查中的剂量

在线全文

学校读者我要写书评

暂无评论

中国临床研究 2024年第4期37卷 519-524页

作者：王伯花刘凤芝李希明青岛大学第十一临床医学院山东临沂276000 临沂市中医医院肛肠手术室山东临沂276003 临沂市人民医院麻醉科山东临沂276002

目的探讨在老年患者无痛胃肠镜检查中,脑电双频指数(BIS)监测下应用瑞马唑仑的适宜初始剂量。方法选取2022年8月至11月于临沂市中医医院行无痛胃肠检查的165例老年患者,按照随机数字表法分为A、B、C三组,各55例。所有患者先静脉注射瑞... 详细信息

目的探讨在老年患者无痛胃肠镜检查中,脑电双频指数(BIS)监测下应用瑞马唑仑的适宜初始剂量。方法选取2022年8月至11月于临沂市中医医院行无痛胃肠检查的165例老年患者,按照随机数字表法分为A、B、C三组,各55例。所有患者先静脉注射瑞芬太尼0.30μg/kg,A、B、C三组瑞马唑仑的初始剂量分别为0.15 mg/kg、0.20 mg/kg、0.25 mg/kg。当BIS0.05)。B组、C组体动或呛咳发生率降低(P<0.05),C组低氧血症发生率升高(P<0.05)。结论BIS监测下,在老年患者无痛胃肠镜检查中,应用瑞马唑仑初始剂量0.20 mg/kg镇静效果佳,入镜时间较短,首次追加间隔时间较长,离室早,对呼吸循环影响小,不良反应少。

关键词：脑电双频指数老年无痛胃肠镜瑞马唑仑瑞芬太尼初始剂量血氧饱和度平均动脉压镇静

Fullerene-Intercalated Graphitic Carbon Nitride as a HighPerformance Anode Material for Sodium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2022年第2期5卷 608-616页

作者： Pengju li Yanglin Shen ximing li Wenhuan Huang Xing Lu Shaanxi Key Laboratory of Chemical Additives for Industry College of Chemistry&Chemical EngineeringShaanxi University of Science&TechnologyXi’an 710021China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Two-dimensional(2D)graphitic carbon nitride(g-CN)is a promising anode material for sodium-ion batteries(SIBs),but its insufficient interlayer spacing and poor electronic conductivity impede its sodium storage capacity and cycling ***,we report the fabrication of a fullerene(C_(60))-modified graphitic carbon nitride(C_(60)@CN)material which as an anode material for SIBs shows a high-reversible capacity(430.5 mA h g^(−1) at 0.05 A g^(−1),about 3 times higher than that of pristine g-CN),excellent rate capability(226.6 mA h g^(−1) at 1 A g^(−1))and ultra-long cycle life(101.2 mA h g^(−1) after 5000 cycles at 5 A g^(−1)).Even at a high-active mass loading of 3.7 mg cm^(−2),a reversible capacity of 316.3 mA h g^(−1) can be obtained after 100 *** outstanding performance of C_(60)@CN is attributed to the C_(60) molecules distributed in the g-CN nanosheets,which enhance the electronic conductivity and prevent g-CN sheets from restacking,thus resulting in enlarged interlayer spacing and exposed edge N defects(pyridinic N and pyrrolic N)for sodium-ion ***,a sodium-ion full cell combining C60@CN anode and NVPF@rGO cathode provides high-coulombic efficiency(>96.5%),exceptionally high-energy density(359.8 W h kganode−1 at power density of 105.1 W kganode−1)and excellent cycling stability(89.2%capacity retention over 500 cycles at 1Aganode−1).This work brings new insights into the field of carbon-based anode materials for SIBs.

关键词： energy storage fullerene interlayer distance nitrogen-doped carbon materials

云计算环境中智算AI的安全与隐私保护机制研究

在线全文

学校读者我要写书评

暂无评论

信息与电脑 2024年第1期36卷 211-213页

作者：李希明马先德中电云计算技术有限公司北京100141 天翼云科技有限公司北京100080

智算人工智能(Artificial Intelligence,AI)技术是信息技术领域的新兴核心,可以提高计算机计算效率,推动大数据分析、机器学习和人工智能等新兴技术的发展。文章主要研究云计算环境中智算AI的安全与隐私保护机制,重点探讨高级加密标准(A... 详细信息

智算人工智能(Artificial Intelligence,AI)技术是信息技术领域的新兴核心,可以提高计算机计算效率,推动大数据分析、机器学习和人工智能等新兴技术的发展。文章主要研究云计算环境中智算AI的安全与隐私保护机制,重点探讨高级加密标准(Advanced Encryption Standard,AES)算法的初始化、子密钥生成和加密处理流程,实验测试了算法防御网络入侵攻击的有效性。结果显示,该算法在提升数据安全性方面表现出色,为云计算环境中智算AI的数据安全与隐私保护提供了实践方法。

关键词：云计算智算人工智能(AI) 安全隐私保护高级加密标准(AES)算法

基于云计算的智算AI算法优化与性能评估研究

在线全文

学校读者我要写书评

暂无评论

中国高新科技 2024年第2期 51-52,71页

作者：马先德李希明王振天翼云科技有限公司北京100080 中电云计算技术有限公司北京100141 北京楷登信息技术有限公司北京100080

智算AI是以智能计算为核心,算力的显著提升和人工智能技术的快速发展是当前时代的典型特征。ChatGPT等AI工具以其强大的文本处理能力迅速席卷全球,掀起了智算时代的大幕。基于这一背景,在云计算场景下优化AI算法成为了提高AI技术性能的... 详细信息

智算AI是以智能计算为核心,算力的显著提升和人工智能技术的快速发展是当前时代的典型特征。ChatGPT等AI工具以其强大的文本处理能力迅速席卷全球,掀起了智算时代的大幕。基于这一背景,在云计算场景下优化AI算法成为了提高AI技术性能的关键任务。文章分析了ChatGPT中变换器模型自注意力机制算法,设计了算法优化过程,旨在通过计算复杂度的降低提升模型的效率。实验结果表明,优化后的模型在保持准确率的同时显著提升了计算效率,提升了云计算场景下的智算AI算法性能,可为人工智能技术的发展提供借鉴。

关键词：云计算智算AI 算法优化性能评估