检索结果-内蒙古大学图书馆

Fault-induced gear meshing modulation sideband extraction and evaluation for fault diagnosis of planetary gearboxes

Science China(Technological Sciences) 2025年第1期68卷 335-351页

作者： Peng ZHOU Xiaoluo YU Yang YANG Qingbo HE Zhike PENG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China School of Mechanical Engineering Ningxia UniversityYinchuan 750021China Science and Technology on Vehicle Transmission Laboratory China North Vehicle InstituteBeijing 100072China

Gearboxes,known for their compact size and stable transmission capability,are widely used as power transmission structures in various types of mechanical equipment,such as wind turbines,helicopters,and special ***,due to harsh and non-stationary working conditions,gear surfaces often deteriorate,leading to faults such as wear,pitting,and ***,it is vital to monitor the working status of gearboxes and diagnose gear faults as early as *** faults can induce characteristic modulation effects near the gear meshing frequency(GMF),resulting in the appearance of faultinduced sidebands in a vibration *** of these sidebands allows for the diagnosis of gear faults in a ***,when faced with a planetary gearbox having a complex configuration,strong background noise and additional faultunrelated sidebands can interfere with fault-induced sidebands,making accurate diagnosis *** address these challenging issues,this paper proposes a novel fault-induced gear meshing modulation sideband extraction *** the process,the sidebands directly related to the gear fault near the GMF are first identified and then extracted by a variational harmonic mode decomposition(VHMD)***,a fault-related gear meshing modulation component(GMMC)can be accurately reconstructed by summing up the extracted fault-induced *** the GMMC,the gear fault severity can be assessed by evaluating its amplitude modulation(AM)*** superior performance of the proposed method is finally demonstrated by experimental data.

关键词： planetary gearbox gear meshing frequency modulation sideband signal decomposition fault diagnosis

来源：评论

学校读者我要写书评

暂无评论

Kirigami-inspired continuum soft arm with embedded sensing for non-destructive inspection and sorting

引用

Science China Materials 2025年第2期68卷 552-560页

作者： Jinsui Xu Boyi Xu Honghao Yue Yifan Lu Zheping Wang Zongquan Deng Fei Yang State Key Laboratory of Robotics and System School of Mechatronics EngineeringHarbin Institute of TechnologyHarbin 150001China Wu Xianming School of Intelligent Engineering South China University of TechnologyGuangzhou 510641China

The sensing capabilities of a soft arm are ofparamount importance to its overall performance as they allow precise control of the soft arm and enhance its interactionwith the surrounding environment. However, the actuationand sensing of a soft arm are not typically integrated into amonolithic structure, which would impede the arm’s movement and restrict its performance and application scope. Toaddress this limitation, this study proposes an innovativemethod for the integrated design of actuator structures andsensing. The proposed method combines the art of kirigamiwith soft robotics technology. In the proposed method, sensorsare embedded in the form of kirigami structures into actuatorsusing laser cutting technology, achieving seamless integrationwith a soft arm. Compared to the traditional amanogawakirigami and fractal-cut kirigami structures, the proposedmiddle-cut kirigami (MCK) structure does not buckle duringstretching and exhibits superior tensile performance. Based onthe MCK structure, an advanced interdigitated capacitivesensor with a high degree of linearity, which can significantlyoutperform traditional kirigami sensors, is developed. Theexperimental results validate the effectiveness of the proposedsoft arm design in actual logistics sorting tasks, demonstratingthat it is capable of accurately sorting objects based on sensorsignals. In addition, the results indicate that the developedcontinuum soft arm and its embedded kirigami sensors havegreat potential in the field of logistics automation *** work provides a promising solution for high-precisionclosed-loop feedback control and environmental interaction ofsoft arms.

关键词： kirigami embedded sensing continuous soft arm non-destructive inspection

来源：评论

学校读者我要写书评

暂无评论

The corrosion and activation mechanism of thiophenic sulfides in the oil-paper insulation

引用

IEEE Transactions on Dielectrics and Electrical Insulation 2025年第3期32卷 1353-1363页

作者： Gao, Sihang Lei, Yuqing Liu, Yongxi Huang, Cong Yang, Lijun Chongqing University of Posts and Telecommunications College of Automation Chongqing China Chongqing University State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing China

The corrosive sulfides in the insulating oil have been confirmed to induce insulation faults, thereby the corrosive sulfides can be removed during the refining process of oil to overcome the corrosion threat. Some inactive sulfides are retained to improve the oxidation stability of oil, mainly including thiophenic sulfides. However, the activation of thiophenic sulfides under the operating conditions and whether it causes corrosion of copper winding remain unclear. Therefore, this paper focuses on the reaction mechanism of copper winding corrosion induced by the pyrolysis of thiophenic sulfides in oil from the perspective of microscopic reaction mechanism, mainly including the analysis of thermal decomposition products of thiophenic sulfides, the activation energy of thiophenic sulfides on varied heating rates, the molecular dynamics simulation of thiophenic sulfides degradation and the thermal ageing verification test. The results indicate that the pyrolysis products of thiophenic sulfides consist of sulfur-containing micromolecules and inorganic products, such as hydrogen sulfide and its ion (H2S, HS-), elemental sulfur (S, S2), and hydrogen and its ion (H2, H+), etc. Thiophene has the lowest activation energy, thereby it is the most prone to pyrolysis, followed by benzothiophene and dibenzothiophene. The continuous energy accumulation results in the decomposition of thiophenic sulfides due to long-term thermal action and generate low molecular corrosive sulfides, further intensifying the oil corrosivity, and leading to the corrosion of oil-paper insulation. © 1994-2012 IEEE.

关键词： Activation energy

来源：评论

学校读者我要写书评

暂无评论

Impacts of Land–Atmosphere Coupling on Summer Extreme Hot-Humid Compound Events over Southern Eurasia under Different Sea Surface Temperature Backgrounds

引用

Advances in Atmospheric Sciences 2025年第4期42卷 744-760页

作者： Yajing QI Haishan CHEN Siguang ZHU State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

Land–atmosphere coupling and sea surface temperature(SST)anomalies both have essential impacts on weather and climate *** on the ERA5 reanalysis dataset and the CESM1.2.2 model,this study investigates the influence of land–atmosphere coupling on summer extreme hot-humid events(EHHE)over southern Eurasia under different SST *** results suggest that coupling causes near-surface air temperature increases that exceed 0.5℃.From 1961 to 2020,the frequency of EHHE has continuously increased,and is closely related to soil moisture anomalies in the northern Indian Peninsula(IDP)and the middle and lower reaches of the Yangtze River(YRB).Numerical simulations further demonstrate that land–atmosphere coupling raises the risk of EHHE by 25.4%.In a typical El Niño SST background state,intensified land–atmosphere coupling tends to produce notable increases in the frequency of *** dominant processes that land–atmosphere coupling affects the EHHE variations are evidently different between these two *** surface thermal anomalies predominate in the IDP,while moisture conditions are more critical in the *** warm SST anomalies exist,dry soil anomalies in the IDP are prominent,and evaporation is constrained,increasing sensible heat *** geopotential height anomalies are significant,combined with adiabatic warming induced by descending motion and a noticeable warm center in the near-surface *** southward shift of the westerly jet enhances divergence over *** anticyclonic circulation anomalies over the western Pacific are conducive to guiding moisture transport to the YRB,providing a favorable circulation background for the development of summer EHHE.

关键词： land-atmosphere coupling sea surface temperature extreme hot-humid events southern Eurasia

来源：评论

学校读者我要写书评

暂无评论

A merged machine learning model for seasonal climate prediction in China

引用

Science China Earth Sciences 2025年第5期68卷 1469-1484页

作者： Danwei QIAN Yanyan HUANG Huijun WANG State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences

Improving the current level of skill in seasonal climate prediction is urgent for achieving sustainable socioeconomic development, and this is especially true in China where meteorological disasters are experienced frequently. In this study, based upon big climate data and traditional statistical prediction experiences, a merged machine learning model(Y-model) was developed to address this, as well as to further explore unknown potential predictors. In Y-model, empirical orthogonal function analysis was firstly applied to reduce the data dimensionality of the target predictand(temperature and precipitation in the four seasons over China). Image recognition techniques were used to automatically identify possible predictors from the big climate data. These predictors, associated with significant circulation anomalies, were recombined into a large ensemble according to different threshold settings for five factors determining the statistical forecast skill. Facebook Prophet was chosen to conduct the independent hindcasts for each season's climate at a lead time of two months. During 2011–2022, the seasonal climate in China was skillfully predicted by Y-model, with an averaged pattern correlation coefficient skill of 0.60 for temperature and 0.24 for precipitation, outperforming CFSv2. Potential predictor analysis for recent extreme events suggested that prior signals from the Indian Ocean and the stratosphere were important for determining the super Mei-yu in 2020, while the prior sea surface temperature over the western Pacific and the soil temperature over West Asia may have contributed to the extreme high temperatures in 2022. Our study provides new insights for seasonal climate prediction in China.

关键词： Machine learning Seasonal climate prediction China’s climate Image recognition techniques Large ensemble

来源：评论

学校读者我要写书评

暂无评论

High-precision magnetic field measurement system based on a coherent population trapping magnetometer onboard the SATech-01 satellite

引用

Science China(Technological Sciences) 2025年第2期68卷 227-242页

作者： Hongbo XUE Wei SONG Haoran ZHAO Yiteng ZHANG Shanzhi YE Jindong WANG Ran TAO Peng SANG Keli CHEN Xingzi BI Bingjun CHENG Bin ZHOU Yongliang XUE Yingying TANG Liu LIU Jinsong LI Xiaocheng ZHU Baoquan LI Jinguo LIU Wen CHEN Xiaofeng ZHANG Yonghe ZHANG Lei LI State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing 100190China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201304China

On July 27,2022,a high-precision system for measuring the magnetic field based on a coherent population trapping magnetometer(referred to as the CPT system)was launched onboard the Space Advanced technology demonstration satellite(SATech-01)by a ZK-1A *** payload comprises a scalar coherent population trapping magnetometer(CPTM),triaxial anisotropic magnetoresistance magnetometer(AMRM),and nano star tracker mounted on a non-magnetic telescopic tubular *** configuration enables synchronized measurement of scalar and vector geomagnetic fields,as well as the attitude,making the payload with its compact sensors suitable for applications on miniature satellite *** November 7,2022,the novel telescopic tubular mast was deployed in orbit,extending to a length of 5.28 *** CPTM,an absolute scalar magnetometer with an omnidirectional sensor,is the first China-developed quantum/atomic magnetometer successfully operating in *** orbit,the CPTM has sensitivity of~10 pT/Hz^(1/2) and can automatically operate under complex magnetic field *** difference between the scalar fields obtained using the CPTM and CHAOS model has a mean deviation of -3.73 nT and a standard deviation of 26.11 nT(1σ),without on-orbit calibration or *** miniaturized AMRM has a sensitivity of~0.3 nT/Hz^(1/2) and maintains stable and reliable operation in *** low-power and miniaturized nano star tracker has a measurement uncertainty of 14.23″(1σ)in *** mission has realized the on-orbit technical verification of the integrated and synchronized detection of the vector magnetic field and attitude and fully validated the system’s performance,automation level,and reliability.

关键词： magnetic field measurement system coherent population trapping magnetometer anisotropic magnetoresistance magnetometer nano star tracker non-magnetic telescopic tubular mast satellite

来源：评论

学校读者我要写书评

暂无评论

AC Surface Flashover and Breakdown Strength Study of Boron Nitride Epoxy Resin Composite 19th

AC Surface Flashover and Breakdown Strength Study of Boron N...

引用

19th Annual Conference of China Electrotechnical Society, ACCES 2024

作者： Cai, Ru Huang, Zhengyong He, Run Bai, Haoyu Li, Jian State Key Laboratory of Transmission and Distribution Equipment and System Safety and New Technology of Chongqing University Chongqing China

ISBN: (纸本)9789819613908

Epoxy resin nanocomposites are widely used in the field of electrical insulation due to their excellent electrical, thermal and mechanical properties. Hexagonal boron nitride (hBN) is often used as a filler for epoxy resin modification due to its unique structure and various excellent properties. In this paper, boron nitride was selected as a filler to study the insulating properties of boron nitride epoxy composite resin under AC. To this end, different contents of hexagonal boron nitride epoxy resin composites were prepared, and AC along surface flashover and AC breakdown experiments were carried out for epoxy resin composites with different contents of hexagonal boron nitride at different temperatures, respectively. The results show that compared with the pure epoxy resin, the doping of hexagonal boron nitride filler affects the insulating property of the epoxy resin, and the AC along-surface flashover voltage and AC breakdown voltage are significantly changed with different hBN contents;the insulating property of the epoxy composite resin is the best when the hBN content is 20 wt%, and the AC along-surface flashover voltage and the AC breakdown voltage reach the maximum. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： III-V semiconductors

来源：评论

学校读者我要写书评

暂无评论

Nonlocal Huygens'meta-lens for high-qualityfactor spin-multiplexing imaging

引用

Light(Science & Applications) 2025年第3期14卷 695-702页

作者： Jin Yao Yubin Fan Yunhui Gao Rong Lin Zhihui Wang Mu Ku Chen Shumin Xiao Din Ping Tsai Department of Electrical Engineering City University of Hong KongKowloonHong Kong SARChina Centre for Biosystems Neuroscienceand NanotechnologyCity University of Hong KongKowloonHong Kong SARChina State Key Laboratory of Terahertz and Milimeter Waves City University of Hong KongKowloonHong Kong SARChina State Key Laboratory on Tunable Laser Technology Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information SystemShenzhen Graduate SchoolHarbin Institute of TechnologyShenzhen 518055China Pengcheng Laboratory ShenzhenChina

Combining bright-feld and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects,which is particularly beneficial for biological *** metalenses present promising candidates for achieving this ***,current multiplexing meta-lenses lack spectral modulation,and crosstalk between different wavelengths hampers the imaging quality,especilly for biological samples requiring precise wavelength ***,we experimentally demonstrate the nonlocal Huygens'meta-lens for high-quality-factor spin-multiplexing ***-bound states in the continuum(q-BlCs)are excited to provide a high quality factor of 90 and incident-angle *** generalized Kerker condition,driven by Fano-like interactions between q-BIC and in-plane Mie resonances,breaks the radiation symmetry,resulting in a transmission peak with a geometric phase for polarization-converted light,while unconverted light exhibits a transmission dip without a geometric *** polarization conversion efficiency of 65%is achieved,accompanied by a minimal unconverted value,surpassing the theoretical limit of traditional thin nonlocal *** these effects,the output polarization-converted state exhibits an efficient wavelengthselective focusing phase *** unconverted counterpart serves as an effective spatial frequency filter based on incident-angular dispersion,passing high-frequency edge ***-field imaging and edge detection are thus presented under two output spin *** work provides a versatile framework for nonlocal metasurfaces,boosting biomedical imaging and sensing applications.

关键词： nonlocal Huygensmeta lens biological imagingmultiplexing metalenses bright field imaging edge enhanced imaging high quality factor spin multiplexing imaging extracting complex morphological information biological samples spectral modulationand

来源：评论

学校读者我要写书评

暂无评论

Enhanced influence of the North Atlantic Oscillation on winter snowfall in northern China since 2000

引用

Science China Earth Sciences 2025年第4期68卷 1236-1244页

作者： Botao ZHOU Chuer GUO Yuepeng HU Wenxin XIE Bo SUN Tingting HAN Ning SHI State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing210044China Zhejiang Meteorological Observatory Hangzhou310002China

Because of the profound impacts of snowfall in northern China on the economy society and human lives,it is essential to understand the physical mechanisms behind the variability of snowfall in this *** on the observational and reanalysis data during 1961–2018,this study examines the relationship of winter snowfall over northern China with the North Atlantic Oscillation(NAO).The results show that their relationship experiences an interdecadal change around *** 2000–2018,the NAO is significantly and negatively correlated to winter snowfall in northern *** the NAO is in the negative phase,the East Asian subtropical jet and polar front jet tend to move northward and southward,respectively,concomitant with an anomalous cyclonic circulation from Lake Balkhash to Lake Baikal in the middle and lower *** an atmospheric background favors the increase of snowfall over northern China by empowering the interactions of cold air with moist airflows in the target ***,during 1981–1999,the association of the NAO with the above atmospheric circulations seems inconspicuous,thereby reducing its relation to winter snowfall in northern *** investigation suggests that the enhancement of the connection between the NAO and aforementioned atmospheric circulations may result from the westward displacement of the NAO southern center from the former period to the latter period.

关键词： Winter snowfall Northern China North Atlantic Oscillation Interdecadal change Atmospheric circulations

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation of the vacuum casting process of solid propellants 3

Numerical simulation of the vacuum casting process of solid ...

引用

2024 3rd International Conference on Acoustics, Fluid Mechanics and Engineering, AFME 2024

作者： Gao, Zhe Wei, Ming Li, Wensen Chen, Cunzhuang Li, Changle Zhao, Jie State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin150000 China Hubei Institute of Aerospace Chemical Technology Xiangyang441003 China

Solid propellant is one of the main components of rocket engines, and the casting of low-viscosity propellant slurry usually uses a vacuum casting process. During the vacuum casting process, the rheological properties of solid propellant slurry are complex, and the theoretical analytical method cannot intuitively and accurately analyze its flow characteristics. Therefore, this paper numerically simulates the casting process through simulation software, uses the Herschel-Bulkley model to characterize the changes in the flow characteristics of solid propellant slurry during the vacuum casting process, and studies the effects of different hopper angles and anti-break vacuum plug shapes on the slurry's rheological properties. By analyzing parameters such as slurry mass flow rate, velocity, residual amount in the hopper, and surface pressure of the plug, the appropriate hopper angle and the bottom edge angle of the anti-break vacuum plug are selected. Finally, the slurry leveling characteristics under suitable hopper and plug conditions are analyzed. The results indicate that a hopper angle of 140° and an anti-break vacuum plug bottom angle of 120° are optimal. The entire vacuum casting process takes approximately 42 seconds, and the overall slurry leveling is good. As the casting progresses, the slurry gradually compacts and levels out, and the bubbles at the bottom of both sides of the combustion chamber gradually disappear. © Published under licence by IOP Publishing Ltd.

关键词： Hoppers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：