检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

仿生六足折纸机器人结构设计与运动分析

浙江大学学报（工学版） 2024年第8期58卷 1543-1555页

作者：曹东兴贾艳超郭翔鹰毛佳佳北京工业大学数学统计学与力学学院北京100124 北京工业大学机械结构非线性振动与强度北京市重点实验室北京100124 北京工业大学机械与能源工程学院北京100124

针对现有折纸机器人组成结构单一,运动不够灵活的问题,将折纸结构与多足机器人设计相结合,耦合三浦折纸和六折痕折纸,提出新型的仿螃蟹六足折纸机器人设计方案,扩展了折纸机器人的运动构型,提升了折纸机器人的运动灵活性.在面对称假设下... 详细信息

针对现有折纸机器人组成结构单一,运动不够灵活的问题,将折纸结构与多足机器人设计相结合,耦合三浦折纸和六折痕折纸,提出新型的仿螃蟹六足折纸机器人设计方案,扩展了折纸机器人的运动构型,提升了折纸机器人的运动灵活性.在面对称假设下,该机器人单足具有2个自由度,此时将机器人腿部顶点等效为关节,轴线折痕等效为连杆,建立机器人腿部的平面连杆等效模型,并以折面夹角为运动变量,通过仿真计算得出机器人足端的理论运动范围.利用楔形面板技术对折面增厚并避免相邻折面发生物理干涉,建模得到折纸仿螃蟹六足机器人的三维模型.基于平面连杆的等效模型,分析折面夹角与足端运动之间的联系,设计确定机器人的足端运动轨迹与运动步态.利用3D打印技术设计并制作折纸仿生六足机器人试验样机,基于STM32单片机控制实现了机器人三横向角步态运动.结果表明,该折纸仿生机器人可以实现平面构型到仿螃蟹构型的转换,在6条腿的协同运动下,机器人可以平稳地左右横向移动.

关键词：六足机器人仿生六折痕折纸三浦折纸运动分析

Nonlocal thermal buckling and postbuckling of functionally graded graphene nanoplatelet reinforced piezoelectric micro-plate

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2022年第3期43卷 341-354页

作者： Shuai WANG jiajia mao Wei ZHANG Haoming LU Beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China No.310 Institute the Third Academy of China Aerospace Science and Industry CorporationBeijing 100074China

This paper analyzes the nonlocal thermal buckling and postbuckling behaviors of a multi-layered graphene nanoplatelet(GPL)reinforced piezoelectric *** GPLs are supposed to disperse as a gradient pattern in the composite micro-plate along its *** effective material properties are calculated by the Halpin-Tsai parallel model and mixture rule for the functionally graded GPL reinforced piezoelectric(FG-GRP)*** equations for the nonlocal thermal buckling and postbuckling behaviors of the FG-GRP micro-plate are obtained by the first-order shear deformation theory,the von Kármán nonlinear theory,and the minimum potential energy *** differential quadrature(DQ)method and iterative method are introduced to numerically analyze the effects of the external electric voltage,the distribution pattern and characteristic of GPLs,and the nonlocal parameter on the critical buckling behaviors and postbuckling equilibrium path of the FG-GRP micro-plate in thermal environment.

关键词： graphene reinforced composite functionally graded(FG)plate thermal buckling thermal postbuckling nonlocal theory small-scale effect

螺旋形压电悬臂梁多方向振动能量采集器设计及性能分析

在线全文

学校读者我要写书评

暂无评论

传感技术学报 2024年第4期37卷 551-557页

作者：曹东兴詹昌海李莎莎毛佳佳北京工业大学材料与制造学部机械结构非线性振动与强度北京市重点实验室

为适应振动环境多方向激励输入，提出一种基于螺旋形压电悬臂梁结构的多方向振动能量采集器。首先把聚偏氟乙烯（PVDF）粘贴在紫铜基层上组成螺旋压电片，进一步由四个螺旋压电片组成双向耦合的振动能量采集器。通过有限元仿真和实验分... 详细信息

为适应振动环境多方向激励输入，提出一种基于螺旋形压电悬臂梁结构的多方向振动能量采集器。首先把聚偏氟乙烯（PVDF）粘贴在紫铜基层上组成螺旋压电片，进一步由四个螺旋压电片组成双向耦合的振动能量采集器。通过有限元仿真和实验分析单螺旋压电片和四片耦合的多方向振动能量采集器的振动特性及能量采集特性，探讨了螺旋形结构几何参数和附加质量对其固有频率的影响、负载电阻对其输出功率的影响以及在不同负载下的开路输出电压和功率。结果表明，半径、径向节距、配重质量和厚度对对单片螺旋压电片的固有频率影响较大。通过对其附加5 g和10 g附加质量，将第一阶固有频率从无附加质量的29 Hz分别降至22 Hz和18 Hz;最佳外接电阻为1×10～7Ω,峰值电压和功率分别为12 V和7μW。对于由四片螺旋压电片组成的多方向振动能量采集器，结果表明其在5 m/s2加速度激振器激励时，输出电压最高可达17 V,具有良好的低频振动能量多方向采集的效果。

关键词：振动能量采集螺旋压电梁多方向低频振动固有频率

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

微波辐射计联合云雷达的相对湿度校正方法

应用气象学报 2024年第5期35卷 551-563页

作者：张婷焦志敏茆佳佳张雪芬王彦霏陈沛宇金龙河北省气象技术装备中心石家庄050000 中国气象局气象探测中心北京100081

基于中国气象局大气探测试验基地地基遥感垂直廓线系统中云雷达与微波辐射计同址观测的优势,使用2021年8月—2022年7月毫米波云雷达、探空数据,分析云雷达反射率因子与相对湿度特征关系,提出联合云雷达的微波辐射计相对湿度分段校正方法... 详细信息

基于中国气象局大气探测试验基地地基遥感垂直廓线系统中云雷达与微波辐射计同址观测的优势,使用2021年8月—2022年7月毫米波云雷达、探空数据,分析云雷达反射率因子与相对湿度特征关系,提出联合云雷达的微波辐射计相对湿度分段校正方法,实现云区微波辐射计相对湿度实时校正,并利用2023年1—8月探空和2023年7—8月ERA5(ECMWF reanalysis version 5)逐小时再分析数据进行误差分析。结果表明:入云区的相对湿度与反射率因子间呈正相关关系,云区中段相对湿度近似饱和状态,出云区与入云区相对湿度随高度变化近似对称;层状云条件下校正后微波辐射计与探空和ERA5相对湿度的均方根误差比校正前分别减小7.99%和8.91%,偏差中位数绝对值分别减小12.62%和13.05%,且连续观测时次经校正后误差均减小,校正效果较好;对流云条件下校正效果也较好,但部分个例存在过度校正。因此,联合云雷达的相对湿度分段校正方法能够实现微波辐射计相对湿度廓线的连续实时校正,可提高有云条件下微波辐射计的观测质量。

关键词：微波辐射计毫米波云雷达相对湿度云

基于激光雷达和微波辐射计的气溶胶质量浓度反演算法研究与分析

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

中国激光 2024年第5期51卷 196-205页

作者：季承荔陈臻懿黄艺峰茆佳佳王志成古锐昌刘爱明张春生项衍中国气象局气象探测中心北京100081 中国气象局气象探测工程技术研究中心北京100081 北京工商大学轻工科学与工程学院北京100048 深圳市国家气候观象台广东深圳518040 安徽大学物质科学与信息技术研究院安徽合肥230601

大气气溶胶是重要的大气污染物之一,气溶胶质量浓度的垂直分布及其与气象要素的相互影响,对理解大气污染传输具有重要意义。激光雷达因具有高时空分辨率的探测优势而成为研究气溶胶颗粒物立体分布的有力工具。本文利用深圳米散射激光雷... 详细信息

大气气溶胶是重要的大气污染物之一,气溶胶质量浓度的垂直分布及其与气象要素的相互影响,对理解大气污染传输具有重要意义。激光雷达因具有高时空分辨率的探测优势而成为研究气溶胶颗粒物立体分布的有力工具。本文利用深圳米散射激光雷达、微波辐射计和近地面气溶胶质量浓度监测仪,根据均方差选取最优参数,建立基于消光系数的温湿融合PM_(2.5)质量浓度反演模型,并以深圳气象梯度观测塔4个高度的PM_(2.5)质量浓度小时均值为基准,对模拟结果进行了验证分析。结果显示:模拟值与观测值两者的变化趋势一致性较好,相关系数受模拟高度、相对湿度影响,并进行了晴天、多云天气下的比对,深圳气象梯度观测塔上4个高度的模拟值和实测值相关系数均大于0.68,平均绝对误差和均方根误差最大值分别为6.88μg/m^(3)和18.56μg/m^(3)。比较4个季节的模拟效果发现,冬季的模拟结果准确性要低于其他三个季节。最后通过个例分析,结合地面温度、相对湿度、风场和气压场,分析了深圳夏季颗粒物质量浓度的时空分布特征。

关键词：激光雷达 PM_(2.5)质量浓度消光系数

Li_(2)ZnTi_(3)O_(8)as the host–separator modifier with efficient polysulfides trapping and fast Li^(+)diffusion for lithium-sulfur batteries

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6087-6094页

作者： mao Qian Yakun Tang Lang Liu Yue Zhang Xiaohui Li jiajia Chen State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources Xinjiang UniversityUrumqi 830017China State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen UniversityXiamen 361005China

The diffusion and loss of lithium polysulfides(LiPSs)in lithium-sulfur batteries(LSBs)reduce the sulfur utilization rate and the catalytic conversion efficiency of sulfur species,resulting in early battery ***_(2)ZnTi_(3)O_(8)(LZTO),characterized by its stable spinel structure,exhibits high Li+conductivity and holds great potential as an effective adsorbent for *** study proposes a collaborative design concept of LZTO host–separator modifier,which offers a complementary and matching approach in the cathode side,effectively addressing the challenges associated with dissolution and inadequate conversion of *** functional theory(DFT)calculation substantiates the pronounced chemical affinity of LZTO towards *** importantly,the high efficiency ion transport channels are achieved in separator coating due to the presence of the LZTO ***,the catalytic efficacy of LZTO is validated through meticulous analysis of symmetric batteries and Tafel ***,the LZTO host–separator modifier-based cell displays satisfactory rate capability(1449 and 1166 mAh·g^(−1)at 0.1 and 0.5 C)and an impressively capacity(606 mAh·g^(−1)after 500 cycles at 1 C).The coordinated strategy of host–separator modifier is supposed to have wide applications in LSBs.

关键词： Li_(2)ZnTi_(3)O_(8) lithium-sulfur batteries host-separator modifier catalytic conversion diffusion and loss of LiPSs

Multidimensional hollow SiO_(2)/C nanofibers modified by magnetic nanocrystals for electromagnetic energy conversion and lithium battery storage

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

Nano Research 2024年第8期17卷 7301-7314页

作者： Chen Han Qi Zheng Juncheng Jin jiajia Zhang Wen-Qiang Cao Kun Xiang Min Zhang mao-Sheng Cao Anhui Provincial Laboratory of Biomimetic Sensor and Detecting Technology College of Materials and Chemical EngineeringWest Anhui UniversityLu’an 237012China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Department of Physics Beijing Technology and Business UniversityBeijing 100048China

Multifunctional materials are powerful tools to support the advancement of energy conversion *** with prominent electromagnetic and electrochemical properties can realize the conversion of electromagnetic energy and solve the subsequent storage ***,an electrospinning-thermal reduction method is employed to construct ultrafine nickel nanoparticle modified porous SiO_(2)/C(Ni-SiO_(2)/C)hollow nanofibers as promising materials for applications in both electromagnetic wave absorption(EMA)and lithium-ion ***,when used as an EMA material,the reflection loss(RL)of Ni-SiO_(2)/C can reach−47.8 dB at 15.8 GHz with a matching thickness of 2.2 *** excellent microwave absorption performance can be attributed to the enhanced conduction loss,polarization relaxation,synergistic magnetic loss,and preferred impedance matching,which result from multi-component magnetic/dielectric synergy and the unique interconnected multidimensional hollow ***,the electronic conductivity and electrochemical activity of the samples are significantly enhanced due to the uniform distribution of ultrafine Ni nanoparticles in the amorphous SiO_(2)/C ***,the hierarchical hollow porous structure provides sufficient free space for volume change during lithiation/delithiation ***,the Ni-SiO_(2)/C nanocomposite exhibits a high reversible capacity of 917.6 mAh·g^(−1)at 0.1 A·g^(−1).At a high current density of 2 A·g^(−1),a capacity of 563.9 mAh·g^(−1)can be maintained after 300 *** energy conversion-storage device is designed to store waste electromagnetic energy in the form of useful electrical *** work inspires the development of high-performance bifunctional materials.

关键词： Ni-SiO_(2)/C nanofiber electromagnetic absorption lithium-ion storage electrospinning multidimensional structure

Constructed Mott-Schottky Heterostructure Catalyst to Trigger Interface Disturbance and Manipulate Redox Kinetics in Li-O_(2) Battery

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

Nano-Micro Letters 2024年第12期16卷 42-58页

作者： Yongji Xia Le Wang Guiyang Gao Tianle mao Zhenjia Wang Xuefeng Jin Zheyu Hong jiajia Han Dong-Liang Peng Guanghui Yue State Key Lab of Physical Chemistry of Solid Surface Fujian Key Laboratory of Surface and Interface Engineering for High Performance MaterialsCollege of MaterialsXiamen UniversityXiamen 361005People’s Republic of China

Lithium-oxygen batteries(LOBs)with high energy density are a promising advanced energy storage ***,the slow cathodic redox kinetics during cycling causes the discharge products to fail to decompose in time,resulting in large polarization and battery failure in a short ***,a self-supporting interconnected nanosheet array network NiCo_(2)O_(4)/MnO_(2)with a Mott-Schottky heterostructure on titanium paper(TP-NCO/MO)is ingeniously designed as an efficient cathode catalyst material for *** heterostructure can accelerate electron transfer and influence the charge transfer process during adsorption of intermediate by triggering the interface disturbance at the heterogeneous interface,thus accelerating oxygen reduction and oxygen evolution kinetics and regulating product decomposition,which is expected to solve the above *** meticulously designed unique structural advantages enable the TP-NCO/MO cathode catalyst to exhibit an astounding ultra-long cycle life of 800 cycles and an extraordinarily low overpotential of 0.73 *** study utilizes a simple method to cleverly regulate the morphology of the discharge products by constructing a Mott-Schottky heterostructure,providing important reference for the design of efficient catalysts aimed at optimizing the adsorption of reaction intermediates.

关键词： Mott-Schottky heterostructure Lithium-oxygen batteries Electrocatalysts Electrodeposition

Ta_(2)NiSe_(5) nanosheets as a novel broadband saturable absorber for solid-state pulse laser generation

在线全文

学校读者我要写书评

暂无评论

Science China Materials 2021年第6期64卷 1468-1476页

作者： Bingzheng Yan Haowen Guo Guanbai He jiajia mao Feifei Wang Kejian Yang Baitao Zhang Jingliang He State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China School of Physics Southeast UniversityNanjing 210096China Collaborative Innovation Center of Light Manipulations and Applications Shandong Normal UniversityJinan 250358China

Two-dimensional(2D)ternary chalcogenides have attracted great attentions because of their novel chemical and physical properties arising from the synergistic effect and stoichiometric variation with the additional third element compared with their binary ***,high-quality 2D tantalum nickel selenide(Ta_(2)NiSe_(5))nanosheets are successfully fabricated by a liquid-phase exfoliation(LPE)*** ultrafast excited carrier relaxation time and nonlinear optical absorption response are investigated and reveal that the prepared 2D Ta_(2)NiSe_(5)nanosheets have excellent broadband saturable absorption properties,which are further illustrated by three passively Q-switched(PQS)allsolid-state lasers operating at 1.0,2.0 and 2.8μm with the Ta_(2)NiSe_(5)nanosheet-based saturable absorber(SA).Furthermore,mode-locked laser operation with the pulse width as short as 356 fs is also realized at 1.0μ*** work not only demonstrates the excellent nonlinear optical proprieties and optical modulation performance of Ta_(2)NiSe_(5),but also paves the way for exploring the photonic and optoelectronic proprieties of ternary chalcogenide materials.

关键词： Ta_(2)NiSe_(5) saturable absorbers passively Q-switched lasers ultrafast lasers