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Science China(Information Sciences) 2017年第5期60卷 36-50页

作者： Deshan MENG Houde LIU Yanan LI Wenfu XU Bin LIANG Shenzhen Graduate School Harbin Institute of Technology Department of mechanical and Aerospace Engineering The Ohio State University Shenzhen Key Lab of Space Robotic Technology and Telescience Shenzhen Graduate SchoolTsinghua University

Flexible appendages, such as solar panels, communication antennas and other large structures, are mounted on the base of a space robot and target satellite. The vibration of the flexible structure is excited by operations of a space manipulator. It is very challenging to control the vibration of large flexible appendages for on-orbit operation and, especially when the manipulator operates a non-cooperative target with unknown structural parameters and vibration information. In this study, a hybrid control method is proposed based on wave-based control and PD control methods to control the motion of a manipulator while suppressing the vibration of appendages. First, the rigid-flexible coupled dynamic model of a compounded system is *** is followed by designing a hybrid control strategy combining wave-based control and PD control for restto-rest maneuvers based on the characteristics of the compounded system. Finally, the simulation of a 3D compounded system is provided to verify the effectiveness of the presented approach. The simulation results indicate that the space robot can successfully berth the target while suppressing the vibrations of the structure.

关键词： space robot large flexible spacecraft vibration suppression wave-based control on-orbit operation

Materialization of strained CVD-graphene using thermal mismatch

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Nano research 2015年第6期8卷 2082-2091页

作者： Seung-Mo Lee Sang-Min Kim Min Young Na Hye Jung Chang Kwang-Seop Kim Hyunung Yu Hak-Joo Lee Jae-Hyun Kim Nano-Convergence mechanical systems research division Korea Institute of Machinery & Materials (KIMM) 156 Gajungbuk-ro Yuseong-gu Daejeon 305-343 Republic of Korea Nano Mechatronics University of Science and Technology (UST) 217 Gajeong-ro Yuseong-gu Daejeon 305-333 Republic of Korea Graduate School of Energy Environment Water and Sustainability Korea Advanced Institute of Science & Technology (KAIST) Daejeon 305-701 Republic of Korea Department of Materials Science and Engineering Yonsei University SO Yonsei-ro Seodaemun-gu Seou1120-749 Republic of Korea Advanced Analysis Center Korea Institute of Science and Technology (KIST) Hwarang-ro 14-gil 5 Seongbuk-gu Seoul 130-791 Republic of Korea Korea research Institute of Standards and Science (KRISS) 267 Gajeong-ro Yuseong-gu Daejeon 305-343 Republic of Korea

理论物理预知 graphene 的紧张工程能支配发现财富仍然隐藏在二维(2D ) 压缩了事物理和商品化的基于 graphene 的设备。然而，在大数量拉紧 graphene 生产不是由任何工具的一项容易的任务。这里，我们证明放在各种各样的底层上的 graphe... 详细信息

理论物理预知 graphene 的紧张工程能支配发现财富仍然隐藏在二维(2D ) 压缩了事物理和商品化的基于 graphene 的设备。然而，在大数量拉紧 graphene 生产不是由任何工具的一项容易的任务。这里，我们证明放在各种各样的底层上的 graphene 的热退火能是为与一个大区域准备拉紧的 graphene 的一个令人惊讶地简单的方法。我们在开发拉紧的 graphene 发现界面的粘附玩的那提高的 graphene 底层一个关键角色。考虑在 graphene 和目标底层之间的热失配的有创造性的设备体系结构能使产生紧张能有意被定制。我们相信我们的建议方法能建议一条捷径到 graphene straintronics 的实现。

关键词：热失配石墨应变 CVD 物化凝聚态物理理论物理界面粘合

Morphologies evolution and mechanical behaviors of SiC nanowires reinforced C/(PyC-SiC)_(n)multilayered matrix composites

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Journal of Materials Science & Technology 2022年第1期96卷 190-198页

作者： Xinfa Tian Hejun Li Xiaohong Shi Hongjiao Lin Ningning Yan Tao Feng State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research CenterNorthwestern Polytechnical UniversityXi’an 710072China School of Mechanics Civil Engineering&ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China

SiC nanowires reinforced C/(PyC-SiC)_(n)multilayered matrix composites(SM-CS for short)were prepared by combined with sol-gel and chemical vapor infiltration(CVI)***,(PyC-Si OC);multilayered structure was formed by cycles of impregnation and *** SiOC was transformed into SiC by heat-treatment,and(PyC-SiC)_(n)multilayered structure would be *** the same time,the PyC layer which was designed as the outmost layer could decrease gas supersaturation to form in-situ tubular SiC nanowires on the surface of multilayered *** results of three-point bending test showed that the maximum force of SM-CS composites was increased by the number of cycles of the preparation process,which were up to enhanced by 74.38%compared with C/C composite *** fracture surface showed that the improvement was due to the multiscale reinforcing system of(PyC-SiC)_(n)multilayered structure and SiC *** structure can protect carbon fibers and release stress concentration by induction of *** the mechanical interlocking effect of SiC nanowires could reinforce bonding force of the remaining matrix.

关键词： C/C Multilayered structure SiC nanowires Flexural property

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Protein O-GlcNAcylation homeostasis regulates facultative heterochromatin to fine-tune sog-Dpp signaling during Drosophila early embryogenesis

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Journal of Genetics and Genomics 2023年第12期50卷 948-959页

作者： Yaowen Zhang Haibin Yu Dandan Wang Xiaoyun Lei Yang Meng Na Zhang Fang Chen Lu Lv Qian Pan Hongtao Qin Zhuohua Zhang Daan M.F.van Aalten Kai Yuan Center for Medical Genetics School of Life Sciences&Hunan Key Laboratory of Molecular Precision MedicineDepartment of OncologyXiangya HospitalCentral South UniversityChangshaHunan 410008China State Key Laboratory of Chemo/Biosensing and Chemometrics College of BiologyHunan UniversityChangshaHunan 410082China National Clinical research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan 410008China division of Cell and Developmental Biology School of Life SciencesUniversity of DundeeDundee DD15EHUK Department of Molecular Biology and Genetics University of AarhusAarhus 8000Denmark The Biobank of Xiangya Hospital Central South UniversityChangshaHunan 410008China

Protein O-GlcNAcylation is a monosaccharide post-translational modification maintained by two evolutionarily conserved enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Mutations in human OGT have recently been associated with neurodevelopmental disorders, although the mechanisms linking O-GlcNAc homeostasis to neurodevelopment are not understood. Here, we investigate the effects of perturbing protein O-GlcNAcylation using transgenic Drosophila lines that overexpress a highly active OGA. We reveal that temporal reduction of protein O-GlcNAcylation in early embryos leads to reduced brain size and olfactory learning in adult Drosophila. Downregulation of O-GlcNAcylation induced by the exogenous OGA activity promotes nuclear foci formation of Polycomb-group protein Polyhomeotic and the accumulation of excess K27 trimethylation of histone H3 (H3K27me3) at the mid-blastula transition. These changes interfere with the zygotic expression of several neurodevelopmental genes, particularly short gastrulation (sog), a component of an evolutionarily conserved sog-Decapentaplegic (Dpp) signaling system required for neuroectoderm specification. Our findings highlight the importance of early embryonic O-GlcNAcylation homeostasis for the fidelity of facultative heterochromatin redeployment and initial cell fate commitment of neuronal lineages, suggesting a possible mechanism underpinning OGT-associated intellectual disability.

关键词： Protein O-GlcNAcylation Drosophila Early embryogenesis Polycomb repressive complex Facultative heterochromatin Neurodevelopment sog

预测小Etvs数液-液分离流的压力梯度和平均界面含水率(英文)

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Chinese Journal of Chemical Engineering 2008年第2期16卷 184-191页

作者：刘夷平张华王淑华王经 Institute of Engineering Thermo-Physics School of mechanical Engineering Shanghai Jiao Tong University Institute of Engineering Thermo-Physics School of mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China

The segregated flow pattern, which occurs in a 26.1 mm diameter, horizontal, stainless steel test section, is investigated. Pressure gradient and in situ phase distribution data were obtained for different combinations of phase superficial velocities ranging from 0.05 m·s-1 to 0.96 m·s-1. For the current small E?tv?s number liquid-liquid system (EoD=4.77), the dominant effect of interfacial tension and wall-wetting properties of the liquids over the gravity is considered. The approach introduces the closure relationship for the case of turbulent flow in a rough pipe, and attempts to modify the two-fluid model to account for the curved interface. In present flow rates range, wave amplitudes were found small, while interfacial mixing was observed. An adjustable definition for hydraulic diame- ters of two fluids and interfacial friction factor is adopted. The predicted pressure gradient and in situ phase distri- bution data have been compared with present experimental data and those reported in the literature.

关键词： two-fluid model pressure gradient holdup liquid-liquid flow interfacial shear

Process Capability Analysis of a Centre Lathe Turning Process

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Engineering（科研） 2016年第3期8卷 79-85页

作者： Andrew A. Erameh Nurudeen A. Raji Rasheed O. Durojaye Abiodun A. Yussouff Department of mechanical Engineering Igbinedion University Okada Nigeria Department of mechanical Engineering Lagos State University Ojo Nigeria Department of Structures and Aerodynamics National Space Research and Development Agency Lagos Nigeria Department of Computer Engineering Grace Polytechnic Omu Nigeria

A process capability study is performed for the turning process on a general purpose center lathe in order to verify the process performance and machine ability to perform within specified tolerance limit. The process and machine capability indices were measured to determine the process and machine adequacy for industrial application. The tolerance limits were obtained from the given nominal size of the shaft, using the basic hole system and 90 sample shafts were turned on the lathe machine to specification for varying spindle speed and feed rate of the lathe. Three (3) samples were randomly selected for the turning process of a combination of the spindle speed and feed rate as a subgroup size for a total subgroup of thirty (30). The diameters (representing the quality characteristics) were used to generate control charts and capability histogram for the process. The process is within statistical control but found incapable of meeting up to specification because the capability index (Cp) measured was less than 1 and the machine capability for industrial application is not adequate.

关键词： Center Lathe Specification Control Chart Range Shaft Basic Hole system Process Capability Turning Process

Numerical Study on Air Turbines with Enhanced Techniques for OWC Wave Energy Conversion

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China Ocean Engineering 2017年第5期31卷 517-527页

作者： CUI Ying HYUN Beom-Soo KIM Kilwon Department of Ocean Engineering College of EngineeringOcean University of China division of Naval Architecture and Ocean Engineering Korea Maritime and Ocean University

In recent years,the oscillating water column(OWC) wave energy converter,which can capture wave energy from the ocean,has been widely applied all over the *** the essential part of the OWC system,the impulse and Wells turbines are capable of converting the low pressure pneumatic energy into the mechanical shaft *** an enhanced technique,the design of endplate or ring attached to the blade tip is investigated numerically in this paper.3 D numerical models based on a CFD-software FLUENT 12.0 are established and validated by the corresponding experimental results from the reports of Setoguchi et al.(2004) and Takao et al.(2001).Then the flow fields and non-dimensional evaluating coefficients are calculated and analyzed under steady *** show that the efficiency of impulse turbine with ring can reach up to 0.49 when Ф=1,which is 4% higher than that in the cases for the endplate-type and the original *** the ring-type Wells turbine with fixed guide vanes shows the best performance with the maximal efficiency of 0.55,which is 22% higher than that of the original *** addition,the quasi-steady analysis is used to calculate the mean efficiency and output-work of a wave cycle under sinusoidal flow *** all together,this study provides support for structural optimization of impulse turbine and Wells turbine in the future.

关键词： OWC impulse turbine Wells turbine CFD endplate ring quasi-steady analysis

Mathematical Modelling and Experimental Investigation of a Low Temperature Proton Exchange Membrane Fuel Cell

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Energy and Power Engineering 2020年第11期12卷 653-670页

作者： Keoagile Mogorosi M. Tunde Oladiran Edward Rakgati Department of mechanical Energy and Industrial Engineering Botswana International University of Science and Technology Palapye Botswana Botswana Institute for Technology research and Innovation Gaborone Botswana

This paper presents dynamic modeling of 1000 W EC6C Proton Exchange Membrane fuel cell (PEMFC) manufactured by Edibon. Experiments were carried out to investigate the performance of the system and a dynamic electrical model was implemented in Matlab/Simulink. The simulation model was able to predict efficiency, power and fuel cell potential. The model was also tested with load variations to find out the real time responses. The results were validated by experimental findings. The comparison showed that the model was effective and could be used in optimization of the fuel cell system operated at low temperatures under 80 degrees.

关键词： Fuel Cell Modeling Experiment Simulink Energy

Preparation of Pd/c-Al_(2)O_(3)/nickel foam monolithic catalyst and its performance for selective hydrogenation in a rotating packed bed reactor

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Chinese Journal of Chemical Engineering 2022年第1期35卷 311-319页

作者： Hai-Long Liao Bao-Ju Wang Ya-Zhao Liu Yong Luo Jie-Xin Wang Guang-Wen Chu Jian-Feng Chen State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China

Selective hydrogenation plays an important role in chemical industries,yet its selectivity is usually limited by the mass *** this work,the enhanced hydrogenation selectivity was achieved in a rotating packed bed(RPB)reactor with excellent mass transfer *** to be used under the centrifugal filed,a monolithic catalyst Pd/c-Al_(2)O_(3)/nickel foam suiting for the shape and size of the rotor of RPB reactor was prepared by the electrophoretic deposition *** mechanical strength of the catalyst can meet the requirement of high centrifugal force in the *** hydrogenation selectivity in the RPB reactor using the 3-methyl-1-pentyn-3-ol hydrogenation system was 3–8 times higher than that in a stirred tank reactor under similar *** work proves the feasibility of intensifying the selectivity of hydrogenation process in the RPB reactor.

关键词： Monolithic catalyst Rotating packed bed reactor Hydrogenation Selectivity

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