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高压叶片泵叶片-定子副弹流动压润滑特性研究

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机械工程学报 2024年第8期60卷 308-319页

作者：赵二辉邵波乔妙杰权龙汪成文太原理工大学机械与运载工程学院太原030024 山西中电科技特种装备有限公司太原030032

目前高压叶片泵叶片-定子副间的弹流动压润滑特性尚不清楚,叶片-定子副的过早磨损失效已成为制约叶片泵高压化发展的瓶颈。建立叶片-定子副弹流动压润滑数学模型,结合双色光干涉弹流动压润滑试验和高压叶片泵台架试验,研究叶片-定子副... 详细信息

目前高压叶片泵叶片-定子副间的弹流动压润滑特性尚不清楚,叶片-定子副的过早磨损失效已成为制约叶片泵高压化发展的瓶颈。建立叶片-定子副弹流动压润滑数学模型,结合双色光干涉弹流动压润滑试验和高压叶片泵台架试验,研究叶片-定子副间的压强分布特性、弹性变形特性、油膜厚度分布特性和油膜动压承载特性,并给出不同相位处叶片-定子副间的油膜动压承载分布图。结果显示,吸油区叶片-定子副间油膜较薄,最小油膜厚度约为0.45μm.且宽度方向两端油膜厚度比中部薄约0.01μm.因此,吸油区定子内壁两端边沿区域出现较宽且较严重的磨损。此外,吸油区流体动压也较强,最高局部压强可达1.2 GPa,吸油区油膜动压承担的载荷约占总载荷的14%。通过研究高压叶片泵叶片-定子副间的弹流动压润滑特性,揭示油膜动压承载对叶片-定子副的减阻抗磨机理,为高压叶片泵减阻抗磨优化设计提供理论基础。

关键词：高压叶片泵叶片-定子副弹流润滑油膜承载减阻抗磨

Highly Sensitive Am.onia Gas Sensors at Room.Tem.erature Based on the Catalytic m.chanism.of N,C Coordinated Ni Single-Atom.Active Center

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Nano-m.cro Letters 2024年第12期16卷 515-531页

作者： w.njing quan Jia Shi m.n Zeng w.n Lv Xiyu Chen Chao Fan Yongw.i Zhang Zhou Liu Xiaolu Huang Jianhua Yang Nantao Hu Tao w.ng Zhi Yang National Key Laboratory of Advanced m.cro and Nano m.nufacture Technology Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Departm.nt of m.cro/Nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Shanghai Key Laboratory of Intelligent Sensing and Detection Technology School of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237People’s Republic of China

Significant challenges are posed by the lim.tations of gas sensing m.chanism. for trace-level detection of am.onia(NH3).In this study,w. propose to exploit single-atom.catalytic activation and targeted adsorption properties to achieve highly sensitive and selective NH3 gas ***,Ni singleatom.active sites based on N,C coordination(Ni-N-C)w.re interfacially confined on the surface of tw.-dim.nsional(2D)m.ene nanosheets(Ni-N-C/Ti_(3)C_(2)Tx),and a fully flexible gas sensor(m.PE-Ni-N-C/Ti_(3)C_(2)Tx)w.s *** sensor dem.nstrates a rem.rkable response value to 5 ppm.NH3(27.3%),excellent selectivity for NH3,and a low.theoretical detection lim.t of 12.1 *** analysis by density functional calculation reveals that the Ni single-atom.center w.th N,C coordination exhibits specific targeted adsorption properties for ***,its catalytic activation effect effectively reduces the Gibbs free energy of the sensing elem.ntal reaction,w.ile its electronic structure prom.tes the spill-over effect of reactive oxygen species at the gas-solid *** sensor has a dual-channel sensing m.chanism.of both chem.cal and electronic sensitization,w.ich facilitates efficient electron transfer to the 2D m.ene conductive netw.rk,resulting in the form.tion of the NH3 gas m.lecule sensing ***,the passivation of m.ene edge defects by a conjugated hydrogen bond netw.rk enhances the long-term.stability of m.ene-based electrodes under high hum.dity *** w.rk achieves highly sensitive room.tem.erature NH3 gas detection based on the catalytic m.chanism.of Ni single-atom.active center w.th N,C coordination,w.ich provides a novel gas sensing m.chanism.for room.tem.erature trace gas detection research.

关键词： Gas sensor Single atom Catalytic activation Targeted adsorption End-sealing passivation

Structure,electronic,and nonlinear optical properties of superalkaline m.(3)O(m.Li,Na)doped cyclo[18]carbon

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Chinese Physics B 2024年第2期33卷 311-317页

作者：刘晓东卢其亮罗其全 School of Physics and m.terial Science Anhui UniversityHefei 230601China Institute of Physical Science and Inform.tion Technology Anhui UniversityHefei 230601China Departm.nt of Chem.cal Physics University of Science and Technology of ChinaHefei 230026China

Cyclo[18]carbon has received considerable attention thanks to its novel geom.tric configuration and special electronic *** have low.ionization *** a superalkali in cyclo[18]carbon is an effective m.thod to im.rove the optical properties of the system.because considerable electron transfer *** this paper,the geom.try,bonding properties,electronic structure,absorption spectrum.and nonlinear optical(NLO)properties of superalkaline m.(3)O(m.Li,Na)-doped cyclo[18]carbon w.re studied by using density functional theory.m.(3)O and the C_(18) rings are not *** C_(18) ring still exhibits alternating long and short *** charge transfer betw.en m.(3)O and C_(18) form. stable[m.(3)O]+[C_(18)]-ionic com.lexes.C_(18)m.(3)O(m.Li,Na)show. striking optical nonlinearity,i.e.,their first-and second-order hyperpolarizability(βvec andγ||)increase considerably atλ=1907 nm.and 1460 nm.

关键词： superalkaline doped cyclocarbon structure and electronic properties nonlinear optical properties density functional theory(DFT)

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融合全局和局部信息的铁谱图像自动对焦算法

中国光学（中英文） 2024年第2期17卷 423-434页

作者：刘信良张龙泉冷晟王静秋王晓雷南京航空航天大学直升机传动技术重点实验室江苏南京210016

针对铁谱图像获取时人工对焦误差大、速度慢等问题,提出了一种融合全局信息和局部信息的铁谱图像自动对焦方法。此方法分为两个阶段:全局对焦阶段利用卷积神经网络(Convolutional Neural Netw.rks,CNN)提取整幅图像的特征向量,并利用门... 详细信息

针对铁谱图像获取时人工对焦误差大、速度慢等问题,提出了一种融合全局信息和局部信息的铁谱图像自动对焦方法。此方法分为两个阶段:全局对焦阶段利用卷积神经网络(Convolutional Neural Netw.rks,CNN)提取整幅图像的特征向量,并利用门控循环单元(Gate Recurrent Unit,GRU)融合对焦过程提取的特征,预测当前全局离焦距离,起到粗对焦的作用;局部对焦阶段提取磨粒的特征向量,利用GRU融合当前特征与前一轮对焦提取的特征,并依据最厚磨粒信息,预测当前磨粒离焦距离,起到精对焦的作用。同时,为了提高对焦准确率,提出了结合拉普拉斯梯度的对焦方向判定法。实验结果表明,此算法在测试集上的对焦误差为2.51μm.当景深为2.0μm.对焦准确率为80.1%,平均对焦时间为0.771 s。本文提出的自动对焦方法具有较好的性能,为铁谱图像自动准确采集提供了技术支持。

关键词：自动对焦铁谱图像全局信息局部信息深度学习门控循环单元

载荷对油膜界面滑移及弹流润滑特性的影响研究

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中国机械工程 2024年第9期35卷 1567-1574页

作者：郭闯赵二辉权龙汪成文太原理工大学机械与运载工程学院山西太原030024

为探究恶劣工况下机械传动系统中摩擦副润滑失效的形成和演变机理,建立考虑油膜界面滑移的点接触弹流润滑模型,进行仿真计算,并开展双色光干涉弹流润滑试验,研究载荷对弹流润滑中油膜界面滑移的影响,进而研究界面滑移状态下卷吸速度、... 详细信息

为探究恶劣工况下机械传动系统中摩擦副润滑失效的形成和演变机理,建立考虑油膜界面滑移的点接触弹流润滑模型,进行仿真计算,并开展双色光干涉弹流润滑试验,研究载荷对弹流润滑中油膜界面滑移的影响,进而研究界面滑移状态下卷吸速度、流体动压、油膜厚度、滑移参数等随载荷的变化特性。研究结果表明:随着载荷的增大,界面滑移幅度和滑移范围均显著增大,滑移区域卷吸速度明显下降,滑移区域动压分布趋于均匀,滑移区域产生膜厚堆积并出现入口凹陷特征,滑移区域形状逐渐呈“半月牙形”特征。

关键词：界面滑移点接触弹流润滑极限剪切力滑移长度

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基于氧化锌薄膜声表面波器件的细胞富集方法

声学学报 2024年第3期49卷 398-402页

作者：李英银周伟彭本贤张春秋全浩孟龙中国科学院深圳先进技术研究院劳特伯生物医学成像研究中心深圳518055 东北大学医学与生物信息工程学院沈阳110004

针对常见的铌酸锂等压电单晶在高温易碎裂且不能弯曲等问题,提出了一种区别于传统压电单晶富集细胞的方法。通过磁控溅射技术在硅衬底上制备了厚度为3.83μm.氧化锌薄膜,并用扫描电子显微镜与X射线衍射表征了薄膜性能,在薄膜表面制备... 详细信息

针对常见的铌酸锂等压电单晶在高温易碎裂且不能弯曲等问题,提出了一种区别于传统压电单晶富集细胞的方法。通过磁控溅射技术在硅衬底上制备了厚度为3.83μm.氧化锌薄膜,并用扫描电子显微镜与X射线衍射表征了薄膜性能,在薄膜表面制备了频率为195 m.z的叉指换能器,插入损耗为-33.8 dB,且仿真分析了该器件的声场。结果表明,表面波声束集中在换能器声孔径处,液滴位于声束边缘。实验结果表明,该器件能够驱动液滴产生3.9×10^(-3)m.s流速的涡旋,并在20 s内富集了悬浮于液滴中的微球和人体淋巴细胞,将液滴中细胞的浓度提升55倍。

关键词：声表面波声镊声流氧化锌压电基底细胞富集

Stepped-up developm.nt of accelerator m.ss spectrom.try m.thod for the detection of ^(60)Fe w.th the HI-13 tandem.accelerator

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Nuclear Science and Techniques 2024年第4期35卷 136-143页

作者： Yang Zhang Sheng-quan Yan m.ng He Qing-Zhang Zhao w.n-Hui Zhang Chao-Xin Kan Jian-m.ng Zhou Kang-Ning Li Xiao-Fei w.ng Jian-Cheng Liu Zhao-Hua Peng Zhuo Liang Ai-Ling Li Jian Zheng Qi-w.n Fan Yun-Ju Li You-Bao w.ng Zhi-Hong Li Yang-Ping Shen Ding Nan w.i Nan Yu-Qiang Zhang Jia-Ying-Hao Li Jun-w.n Tian Jiang-Lin Hou Chang-Xin Guo Zhi-Cheng Zhang m.ng-Hao Zhu Yu-w.n Chen Yu-Chen Jiang Tao Tian Jin-long m. Yi-Hui Liu Jing-Yu Dong Run-long Liu m.i-Yue-Nan m. Yong-Shou Chen w.i-Ping Liu Bing Guo China Institute of Atom.c Energy P.O.Box 275(10)Beijing 102413China College of Science Southern University of Science and TechnologyShenzhen 518055China School of Physics Xi’an Jiaotong UniversityXi’an 710049China

The m.on provides a unique environm.nt for investigating nearby astrophysical events such as *** sam.les retain valuable inform.tion from.these events,via detectable long-lived“fingerprint”radionuclides such as^(60)*** this w.rk,w. stepped up the developm.nt of an accelerator m.ss spectrom.try(Am.)m.thod for detecting^(60)Fe using the HI-13tandem.accelerator at the China Institute of Atom.c Energy(CIAE).Since interferences could not be sufficiently rem.ved solely w.th the existing m.gnetic system. of the tandem.accelerator and the follow.ng Q3D m.gnetic spectrograph,a w.en filter w.th a m.xim.m.voltage of±60 kV and a m.xim.m.m.gnetic field of 0.3 T w.s installed after the accelerator m.gnetic system. to low.r the detection background for the low.abundance nuclide^(60)Fe.A 1μm.thick Si_(3)N_(4) foil w.s installed in front of the Q3D as an energy *** particle detection,a m.lti-anode gas ionization cham.er w.s m.unted at the center of the focal plane of the ***,an^(60)Fe sam.le w.th an abundance of 1.125×10^(-10)w.s used to test the new.Am. *** results indicate that^(60)Fe can be clearly distinguished from.the isobar^(60)*** sensitivity w.s assessed to be better than 4.3×10^(-14)based on blank sam.le m.asurem.nts lasting 5.8 h,and the sensitivity could,in principle,be expected to be approxim.tely 2.5×10^(-15)w.en the data w.re accum.lated for 100 h,w.ich is feasible for future lunar sam.le m.asurem.nts because the m.in contam.nants w.re sufficiently separated.

关键词： Accelerator m.ss spectrom.try w.en filter Isobar separation Supernovae Chang'e-5 lunar sam.les

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基于组合间距策略的自适应车辆队列纵向控制

中国公路学报 2024年第2期37卷 239-252页

作者：李永福王兴全黄龙旺黄鑫胡晓松重庆邮电大学自动化学院重庆400065 重庆邮电大学智能空地协同控制重庆市高校重点实验室重庆400065 重庆大学机械与运载工程学院重庆400044

针对车辆队列被外部车辆换道超车的场景,外部车辆与队列中的车辆存在异质性,不同车辆适用的间距策略也存在差异性。此外,不同的车辆队列间距策略在道路适应性、车辆队列系统稳定性和串稳定性等方面均存在优势和缺陷。基于此提出一种基... 详细信息

针对车辆队列被外部车辆换道超车的场景,外部车辆与队列中的车辆存在异质性,不同车辆适用的间距策略也存在差异性。此外,不同的车辆队列间距策略在道路适应性、车辆队列系统稳定性和串稳定性等方面均存在优势和缺陷。基于此提出一种基于组合间距策略的智能网联车辆队列控制方法,以优化队列车辆的间距。现有的协同/分布式队列控制方法大多基于精确的车辆动力学模型,这要求获得完整的车辆动力学先验知识,并进行非线性-线性模型的转换。然而,在实践中获取精确的先验知识信息往往具有挑战性,且在车辆间进行信息交互的过程中,不可避免地会产生通信时延。因此,在考虑网络环境通信时延的基础上,提出了一种基于自适应积分滑模车辆队列控制器的分布式后向控制方案,该方案可以在线识别和估计未知参数,从而解决三阶车辆节点动力学模型中参数不确定性影响系统稳定性的问题。在设计的积分滑模面中,采用饱和函数替代传统滑模面的符号函数,进一步解决了控制结果中容易出现抖振的问题。然后,利用Lyapunov-Krasovskii定理和无穷范数进行了组合间距策略和间距策略切换下车辆队列系统的内部稳定性和串稳定性分析。最后,通过与现有控制算法进行仿真比较分析,验证了所提出的控制策略和算法的有效性。

关键词：交通工程自适应积分滑模控制组合间距策略智能网联汽车间距策略切换车辆队列控制通信延时

Interpenetrating LiB/Li_(3)BN_(2)phases enabling stable com.osite lithium.m.tal anode

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Science Bulletin 2024年第18期69卷 2842-2852页

作者： Piao Qing Shaozhen Huang Tuoya Naren quan Li Haifeng Huang Kecheng long Zhijian Liu Lin m.i Fu Sun w.ifeng w.i Yu Zhang Jianm.n m. Zhibin w. Libao Chen State Key Laboratory of Pow.er m.tallurgy Central South UniversityChangsha 410083China National Energy m.tal Resources and New.m.terials Key Laboratory Central South UniversityChangsha 410083China Departm.nt of Physics The Chinese University of Hong KongHong Kong 999077China Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Key Laboratory of Bio-inspired Sm.rt Interfacial Science and Technology of m.nistry of Education School of ChemistryBeihang UniversityBeijing 100191China School of Chem.stry Tiangong UniversityTianjin 300387China

Host-less lithium.m.tal anode generally suffers from.large volum. changes and serious dendrite grow.h during cycling,w.ich poses challenges for its practical *** phase com.osites w.th continuous architectures offer a solution to enhance m.chanical properties of ***,a robust com.osite Li anode(LBN)m.terial is fabricated through the m.tallurgical reaction betw.en Li and hexagonal boron nitride(h-BN)w.th the form.tion of interpenetrating LiB/Li_(3)BN_(2)*** LiB fibers are anchored by Li_(3)BN_(2)granules,the collapse and slippage of LiB fibers are suppressed w.ilst the m.chanical strength and structural stability of LBN are *** rolling,ultrathin(15μm.,freestanding,and electrochem.cally stable LBN foil can be *** LBN anode exhibits a high average Coulom.ic efficiency of 99.69%(1 m. cm.(-2),3 m.h cm.(-2))and a long lifespan of 2500 h(1 m. cm.(-2),1 m.Ah cm.(-2)).Notably,the LiCoO_(2)(w.th double-sided load 40 m. cm.(-2))|LBN pouch cell can operate over450 cycles w.th a capacity retention of 90.1%.The exceptional cycling stability of LBN can be ascribed to the interpenetrating reinforcem.nt architectures and synergistic electronic/ionic conductivity of the LiB/Li_(3)BN_(2)*** w.rk provides a new.m.thodology for thin Li strip processing and reinforced-architecture design,w.th im.lications beyond battery applications.

关键词： Li m.tal anode Ultrathin Interpenetrating Li-B alloy Li_(3)BN_(2)