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Contact Behavior of Worn Bearings with Elastoplastic Functionally Graded Coating Based on Mixed Elastohydrodynamic Lubrication

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Acta Mechanica Solida Sinica 2021年第1期34卷 124-136页

作者： Xue-Qian Fang Yao Ning Shao-pu yang Hai-Hua Wang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China Department of Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang050043China Hebei Key Laboratory for Mechanics of Smart Materials and Structures Shijiazhuang050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang050043China

The dynamic contact behavior of worn bearings with elastoplastic functionally graded coating is studied,and the interacting effect between worn band and functionally graded surface is *** surface deformation and roughness are included in the film *** mixed elastohydrodynamic lubrication combined with point contact model is introduced to analyze the oil pressure in the contact *** using the Fourier transform method and Papkovich-Neuber potential function,the displacements and stress fields in the elastoplastic functionally graded coating are *** second-order central difference method is used to solve the Reynolds *** is found that the repeated surface interaction can result in the sharp increase in pressure in bearings,and the oil pressure increases with increasing graded *** entrainment of oil in the inlet and outlet zones becomes more evident if a large graded index is selected.

关键词： Wear bearings Contact behavior Elastoplastic functionally graded surface Mixed elastohydrodynamic lubrication.Central difference method

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板坯连铸机系统改造后边裂问题分析与改进

河南冶金 2024年第3期32卷 26-28,44页

作者：杨杰王立志崔强吴红广杨普安阳钢铁股份有限公司河南安阳455004

板坯连铸机改造后,铸坯连续出现南北两侧振痕不均匀和边裂问题,严重地影响了正常的生产流程,对产品质量控制也造成了很大影响。针对铸坯边裂,依据生产数据和生产跟踪情况,从工艺、设备工况和操作等方面分析,排除了生产工艺和操作因素所... 详细信息

板坯连铸机改造后,铸坯连续出现南北两侧振痕不均匀和边裂问题,严重地影响了正常的生产流程,对产品质量控制也造成了很大影响。针对铸坯边裂,依据生产数据和生产跟踪情况,从工艺、设备工况和操作等方面分析,排除了生产工艺和操作因素所造成的影响,最终确定是由于结晶器起振中心位置不合适导致的。结晶器起振中心位置调整之后,边裂问题明显减少,铸坯质量得到改善,边裂发生率由10.5%降低到0.5%以下。

关键词：板坯边裂控制系统升级改造振动中位

Integrated Towing Transportation Technique for Offshore Wind Turbine with Composite Bucket Foundation

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China Ocean Engineering 2022年第1期36卷 133-143页

作者： DING Hong-yan FENG Zun-tao ZHANG pu-yang LE Cong-huan State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Key Laboratory of Coast Civil Structure Safety Ministry of EducationTianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China

Composite bucket foundation and one-step installation technology for offshore wind turbine are the integration of foundation construction,transportation and whole installation at *** cost of offshore wind turbine construction and installation has been largely *** stability is the key technology in the process of towing *** observation data can reflect the real state of the *** this paper,the influence of water depth and towing speed on liquid level,the compartment pressure,and the pitch angles during towing of composite bucket foundation are *** data are analyzed based on the field measurements data from a 3.3 MW offshore wind power project in *** results show that with varied water depths and towing speeds,the compartment pressure changes are small during the bucket foundation towing *** offshore wind turbine composite bucket foundation is stable while being towed in the ocean.

关键词： composite bucket foundation towing transportation field measurements stability

眼动追踪技术在住院医师超声引导中心静脉穿刺模拟培训中的应用

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中国毕业后医学教育 2024年第1期8卷 63-66页

作者：杨璞于倩王海宁刘鼎中南大学湘雅三医院神经内科湖南长沙410013 中南大学湘雅二医院血液内科湖南长沙410011 湖南大学设计艺术学院湖南长沙410012

目的探索眼动追踪技术在住院医师超声引导中心静脉穿刺模拟培训中的应用。方法选取2020年8月—2022年8月在中南大学湘雅三医院神经内科轮转的住院医师40名,随机分成2组。培训前进行相关基础知识问卷调查,在进行30分钟超声引导中心静脉... 详细信息

目的探索眼动追踪技术在住院医师超声引导中心静脉穿刺模拟培训中的应用。方法选取2020年8月—2022年8月在中南大学湘雅三医院神经内科轮转的住院医师40名,随机分成2组。培训前进行相关基础知识问卷调查,在进行30分钟超声引导中心静脉穿刺理论讲授后,分别进行有或无眼动追踪仪辅助的超声引导中心静脉穿刺模拟训练,培训后进行穿刺操作考核和满意度问卷调查,眼动追踪仪记录考核过程中住院医师的眼动数据。结果培训后接受眼动追踪仪辅助的超声引导中心静脉穿刺教学组考核成绩更好,操作过程中注视超声屏幕的时间比例更高,视线在超声屏幕与穿刺针、探头间切换的次数更少,问卷调查满意度也更高,差异有统计学意义(P<0.05)。结论将眼动追踪技术应用到住院医师超声引导中心静脉穿刺模拟培训中,能引导其有效注视行为,提高学习效果,增强自信心和积极性,提升教学满意度。

关键词：眼动追踪技术超声引导中心静脉穿刺模拟培训住院医师规范化培训

Geochemical fractionation of rare earth elements in lacustrine deposits from Qaidam Basin

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Science China Earth Sciences 2009年第11期52卷 1703-1713页

作者： ZHANG HuCai ZHANG WenXiang CHANG FengQin yang LunQing LEI GuoLiang yang MingSheng pu yang LEI yangBin Key Laboratory of Western China’s Environments MOECollege of Earth Sciences and EnvironmentsLanzhou UniversityLanzhou 730000China State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China Key Laboratory of Boyang Lake MOESchool of Environmental and Chemical EngineeringNanchang UniversityNanchang 330031China

Based on the concentration and distribution pattern analysis of the rare earth elements (REEs) at the Shell Bar section from Qaidam Basin, we studied the geochemical fractionations of REE in paleolake deposits and their paleo-environmental significance. Our results show that the REE concentration in AS (acid soluble) and AR (acid residual) fractions are 20.9 μg/g and 95.4 μg/g (except element Y) individually, showing a strong REE differentiation between AS and AR fractions. However, the two types of fractions (AS & AR) have similar REE distribution patterns, which are slightly rich in light earth rare elements (LREEs), with slightly right-tilting and negative Eu anomaly. The LREE of AR is richer than that of AS. There were no significant correlations between the REE in AS, AR and other proxies. It indicated that the lacustrine deposition had different material sources and experienced varying geochemical procedures. Correlation analysis between the REE and the content of fine grain-size (<4 μm) of the sediments, Rb/Sr ratio and Mn concentration showed high correlation coefficients. Our results demonstrated that the REE in acid soluble and residual fractions bear different environmental significances, which are strongly dependent on local environment. The REE of acid soluble fraction is closely related to the paleoclimatic changes in the lake catchment and the evolutionary processes of lake itself. Our results suggest that δCe and (La/Yb)n could be used as proxies of the reduction-oxidation conditions and furthermore the temperature change and the lake level fluctuations. Using these proxies, we reconstructed the paleoclimate and water level fluctuation history during the high lake level period lasting between 43.5 and 22.4 cal. ka BP.

关键词： Shell Bar section rare earth elements (REE) fractionation paleoclimate Qaidam Basin

Transverse vibrations of arbitrary non-uniform beams

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Applied Mathematics and Mechanics(English Edition) 2014年第5期35卷 607-620页

作者：郭树起杨绍普 Department of Engineering Mechanics Shijiazhuang Tiedao University School of Mechanical Engineering Shijiazhuang Tiedao University

Free and steady state forced transverse vibrations of non-uniform beams are investigated with a proposed method, leading to a series solution. The obtained series is verified to be convergent and linearly independent in a convergence test and by the non-zero value of the corresponding Wronski determinant, respectively. The obtained solution is rigorous, which can be reduced to a classical solution for uniform beams. The proposed method can deal with arbitrary non-uniform Euler-Bernoulli beams in principle, but the methods in terms of special functions or elementary functions can only work in some special cases.

关键词： transverse vibration non-uniform beam series solution convergence

Molecular fossil and paleovegetation records of paleosol S4 and adjacent loess layers in the Luochuan loess section, NW China

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Science China Earth Sciences 2008年第3期51卷 321-330页

作者： ZHANG HuCai yang MingSheng ZHANG WenXiang LEI GuoLiang CHANG FengQin pu yang FAN HongFang Key Laboratory of Western China’s Environmental Systems Ministry of EducationCollege of Earth and Environment SciencesLanzhou UniversityLanzhou 730000China State Key Laboratory of Lake and Environment Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China

Using gas chromatography-mass spectrometry (GC-MS) technique, a series of biomarkers were identi- fied, including n-alkanes, n-alkane-2-ones, isoprenoid etc. from the loess-paleosol samples collected from the S4 and adjacent L5, L4 of the Luochuan loess section, Northwestern China. Based on these data, especially n-alkanes and high-resolution magnetic susceptibility and grain size data, the pa- leoenvironment and paleovegetation history during S4 was reconstructed. The CPI (Carbon Predomi- nance Index) and correlation between n-alkanes and magnetic susceptibility and grain size data dem- onstrated that the molecular fossils in paleosol and loess layers can reflect the vegetation condition during the loess-paleosol formation, if the allochthonous organic inputs could be excluded reasonably. The ACL (average chain length) index is correlated well with paleomagnetic susceptibility and grain size variations, displaying their good synchrony with warm and humid climate. However, it relatively lagged behind the paleomagnetic susceptibility and the grain size variations when the climate began to deteriorate. During the formation period of paleosol, the n-alkanes was dominated by C31 homologue, indicating that the primary organic input originated from herbs. Our study also demonstrated that the herbs were more flourish than wood plants in Loess Plateau, especially in the Luochuan area during the warm and humid phase, and there was no typical forest vegetation developed in the studied period.

关键词： paleoenvironment Paleosol S4 Luochuan loess section biomarker paleovegetation

Effect of Acupuncture Cooperated with Low-frequency Repetitive Transcranial Magnetic Stimulation on Chronic Insomnia： A Randomized Clinical Trial

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Current Medical Science 2018年第3期38卷 491-498页

作者： yang-pu ZHANG Wei-jing LIAO Wen-guang XIA Department of Physical Medicine and Rehabilitation Zhongnan Hospital of Wuhan University Wuhan 430071 China Department of Physical Medicine and Rehabilitation Hubei Provincial Hospital of Integrated Chinese and Western Medicine Wuhan 430015 China

The effect of acupuncture cooperated with low-frequency repetitive transcranial magnetic stimulation （rTMS） on chronic insomnia was explored. Seventy-eight patients with chronic insomnia were randomly allocated into two groups： treatment group and control group. In the treatment group, the patients received acupuncture combined with rTMS treatment, and those in the control group were given acupuncture cooperated with sham rTMS treatment, 3 days per week for 4 weeks. Before and after treatment, the primary outcomes including the scores on Insomnia Severity Index （ISI） and Pittsburgh Sleep Quality Index （PSQI） and the secondary outcomes including total sleep time （TST）, sleep onset latency （SOL）, wake after sleep onset （WASO）, sleep efficiency （SE%） recorded by sleeping diary and actigraphy were observed in both groups. Seventy-five participants finished the study （38 in treatment group and 37 in control group respectively）. After treatment, the scores in the two groups were improved significantly, more significantly in the treatment group than in the control group. It can be inferred that acupuncture cooperated with rTMS can effectively improve sleep quality, enhance the quality of life of patients and has less side effects.

关键词： acupuncture low-frequency repetitive transcranial magnetic stimulation insomnia

Shaking Table Tests of Four-Bucket Jacket Foundation for Offshore Wind Turbines

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China Ocean Engineering 2022年第6期36卷 849-858页

作者： DING Hong-yan LI Jing-yi LE Cong-huan PAN Chen ZHANG pu-yang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China

As the offshore wind turbine foundation,the four-bucket jacket foundation has a large stiffness and the structure is difficult to be damaged under seismic ***,the saturated subsoil of the four-bucket jacket foundation tends to be liquefied under earthquake,which greatly affects the safety of offshore wind ***,the seismic performance of four-bucket jacket foundation is mainly reflected in the anti-liquefaction capacity of foundation *** this paper,the liquefaction resistance of sandy soil of four-bucket jacket foundation for offshore wind turbine is *** liquefaction and dynamic response of sandy soil foundation of four-bucket jacket foundation under seismic load are obtained by carrying out the shaking table test,and the influence mechanism of four-bucket jacket foundation on the liquefaction resistance of sandy soil foundation is analyzed.

关键词： four-bucket jacket foundation sand liquefaction shaking table test seismic response