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DYNAMICS ANALYSIS OF SPECIAL STRUCTURE OF MILLING-HEAD MACHINE TOOL

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Chinese Journal of Mechanical Engineering 2008年第6期21卷 103-107页

作者： YANG Qingdong liu guoqing WANG Keshe College of Machinery and Electricity Engineering Beijing Information Science and Technology University Beijing 100192 China

The milling-head machine tool is a sophisticated and high-quality machine tool of which the spindle system is made up of special multi-element structure. Two special mechanical configurations make the cutting performance of the machine tool decline. One is the milling head spindle supported on two sets of complex bearings. The mechanical dynamic rigidity of milling head structure is researched on designed digital prototype with finite element analysis（FEA） and modal synthesis analysis （ MSA ） for identifying the weak structures. The other is the ram structure hanging on milling head. The structure is researched to get dynamic performance on cutting at different ram extending positions. The analysis results on spindle and ram are used to improve the mechanical configurations and structure in design. The machine tool is built up with modified structure and gets better dynamic rigidity than it was before.

关键词： Milling-head machine tool Dynamic characteristics Finite element analysis Modal synthesis analysis

The Boundary Contour Method for Half-Plane Piezoelectric Media

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上海交通大学学报 2004年第z2期38卷 176-181页

作者： WANG guoqing WANG Qing liu Zhengxing DING Haojiang Department of Engineering Mechanics Shanghai Jiaotong Univ. Shanghai200030 China Department of Engineering Mechanics Shanghai Jiaotong Univ. Shanghai200030 China Department of Engineering Mechanics Shanghai Jiaotong Univ. Shanghai200030 China Department of Civil Engineering Zhejiang Univ. Hangzhou310027 China

This paper presents a further development of the Boundary Contour Method (BCM) for half-plane piezoelectric media. Firstly, the divergence free property of the integrand of the half-plane piezoelectric boundary element is proven. Secondly, the boundary contour method formulation is derived and potential functions are obtained by introducing linear shape functions and Green's functions[1] for half-plane piezoelectric media. Finally, numerical solutions for illustrative example are compared with exact ones and that of conventional boundary element method (BEM) ones. The numerical results of BCM coincide very well with exact solution, and the feasibility and efficiency of the method are verified.

关键词： boundary contour method piezoelectricity half-plane shape function

Preparation of M2O3-CeO2(M=La,Fe,and Al) Compoundoxide Catalyst and Its Degradation Performance

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Journal of Wuhan University of Technology(Materials Science) 2020年第2期35卷 335-341页

作者： LI Youfeng LIN Jinliang XIE Bo liu guoqing School of Chemistry and Chemical Engineering Zunyi Normal CollegeZunyi 563006China School of Chemistry and Chemical En-gineering Hunan University of Science and TechnologyXiangtan 411201China

As one of the most active rare earths,CeO2 has caused extensive concern due to its multifunctional ***2-based compound oxide of M2O3-CeO2(M=La,Fe,and Al)were prepared by coprecipitation and impregnation *** photocatalytic performance of the samples for the degradation methylene blue was studied under UV and visible light *** effects of constituents on the properties of the CeO2-based catalysts were investigated by XRD,TEM,BET,and UV-Vis *** highest degradation of methylene blue under 230W UV light was almost 100%at 50 min by La2O3/Fe2O3-CeO2/γ-Al2O3 catalyst and 99.42%at 50 min by Fe2O3-CeO2/γ-Al2O3 *** methylene blue removal efficiency under indoor natural light reaches 93.81%by La2O3/Fe2O3-CeO2/γ-Al2O3 catalyst and 92.34%by Fe2O3-CeO2/γ-Al2O3 catalyst at 50 *** order of catalytic degradation activity is La2O3/Fe2O3-CeO2/γ-Al2O3>Fe2O3-CeO2/γ-Al2O3>La2O3-CeO2/γ-Al2O3>Al2O3,owing to their structural *** doping of La^3+or Fe3+onto CeO2/γ-Al2O produced much more oxygen vacancies under light irradiation and reduced the energy laps of CeO2 with value of 2.86 ev,which improved the photocatalytic redox performance of the composite oxide.

关键词： CeO2-based compound oxide catalyst degradation catalysis

Semiparametric bounds of mean and variance for exotic options

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Science China Mathematics 2009年第7期52卷 1446-1458页

作者： liu guoqing LI V.Wenbo Department of Mathematics Harbin Institute of TechnologyHarbin 150006China Department of Mathematical Sciences University of DelawareNewarkDE 19716USA

Finding semiparametric bounds for option prices is a widely studied pricing *** obtain closed-form semiparametric bounds of the mean and variance for the pay-off of two exotic(Collar and Gap) call options given mean and variance information on the underlying asset ***,we extended domination technique by quadratic functions to bound mean and variances.

关键词： semiparametric bounds duality moment problem exotic options 60C05 65K10 49M29

Evolutionary direction of processed pseudogenes

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Science China(Life Sciences) 2016年第8期59卷 839-849页

作者： guoqing liu Xiangjun Cui Hong Li Lu Cai School of Life Science and Technology Inner Mongolia University of Science and TechnologyBaotou 014010China 1nstitute of Bioengineering and Technology lnner Mongolia University of Science and TechnologyBaotou 014010China School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China Computational Systems Biology Lab Department of Biochemistry and Molecular BiologyInstitute of BioinformaticsUniversity of GeorgiaAthens GA 30602USA

While some pseudogenes have been reported to play important roles in gene regulation, little is known about the possible relationship between pseudogene functions and evolutionary process of pseudogenes, or about the forces responsible for the pseudogene evolution. In this study, we characterized human processed pseudogenes in terms of evolutionary dynamics. Our results show that pseudogenes tend to evolve toward: lower GC content, strong dinucleotide bias, reduced abundance of transcription factor binding motifs and short palindromes, and decreased ability to form nucleosomes. We explored possible evolutionary forces that shaped the evolution pattern of pseudogenes, and concluded that mutations in pseudogenes are likely determined, at least partially, by neighbor-dependent mutational bias and recombination-associated selection.

关键词： GC content mutual information transcription factor binding motifs mutational bias recombination

Ion-imprinted silica gel and its dynamic membrane for nickel ion removal from wastewaters

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Frontiers of Chemical Science and Engineering 2020年第6期14卷 1018-1028页

作者： Jiehui Zeng Jianxian Zeng Hu Zhou guoqing liu Zhengqiu Yuan Jian Jian School of Chemistry and Chemical Engineering Hunan University of Science and TechnologyXiangtan 411201China

An ion-imprinted sorbent(IIP)was prepared by using Ni^2+ as template,3-[2(2-aminoethylamino)ethylamino]propyl-trimethoxysilane as functional monomer,and silica gel as *** adsorption performance of IIP towards Ni^2+ was *** showed a higher adsorption capacity than that of non-imprinted sorbent,and it also exhibited high selectivity for Ni^2+ in the presence of Cu^2+ and Zn^2+ ***,IIP was used to form a dynamic membrane onto the surface of ceramic membrane for treatment of electroplating wastewater containing Ni^2+.Compared with ceramic membrane,IIP dynamic membrane had much higher steady membrane flux,and also rejected Ni^2+ to obtain a lower concentration of Ni2+ in the permeate *** it is suitable for future practice applications.

关键词： ion-imprinted nickel ion dynamic membrane adsorption

Optimal Rate Allocation Based on Cross-Layer Design and End-to-End Congestion Control in WCDMA Networks

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China Communications 2015年第4期12卷 58-68页

作者： LI Yuzhou SHI Yan SHENG Min liu guoqing XU Chao State Key Laboratory of Integrated Service Networks Xidian University

In this paper, a novel idea for rate allocation combining both vertical coupling and horizontal coupling constraints is proposed, and a unified utility function to balance two paradoxical issues: efficiency and fairness, revenue and cost is elaborated in WCDMA networks. Then, the optimal rate allocation problem is formulated as a network utility maximization(NUM) model based on cross-layer design and end-to-end congestion control, aiming at exploring the impacts of wired networks and the characteristics of radio access networks(RANs) on rate allocation. Furthermore, a distributed algorithm is derived, which can effectively match load states between RANs and wired networks, followed by a detailed illustration of the practical implementations. Numerical results demonstrate a signifi cant performance improvement in the end-to-end throughput.

关键词： cross-layer design efficiency andfairness revenue and cost network utilitymaximization rate allocation

M2C-GVIO:motion manifold constraint aided GNSS-visual-inertial odometry for ground vehicles

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Satellite Navigation 2023年第1期4卷 77-91,I0003页

作者： Tong Hua Ling Pei Tao Li Jie Yin guoqing liu Wenxian Yu Shanghai Key Laboratory of Navigation and Location Based Services Shanghai Jiao Tong UniversityShanghaiChina

Visual-Inertial Odometry(VIO)has been developed from Simultaneous Localization and Mapping(SLAM)as a lowcost and versatile sensor fusion approach and attracted increasing attention in ground vehicle ***,VIOs usually have the degraded performance in challenging environments and degenerated motion *** this paper,we propose a ground vehicle-based VIO algorithm based on the Multi-State Constraint Kalman Filter(MSCKF)*** on a unifed motion manifold assumption,we derive the measurement model of manifold constraints,including velocity,rotation,and translation *** we present a robust flter-based algorithm dedicated to ground vehicles,whose key is the real-time manifold noise estimation and adaptive measurement ***,GNSS position measurements are loosely coupled into our approach,where the transformation between GNSS and VIO frame is optimized ***,we theoretically analyze the system observability matrix and observability *** algorithm is tested on both the simulation test and public datasets including Brno Urban dataset and Kaist Urban *** compare the performance of our algorithm with classical VIO algorithms(MSCKF,VINS-Mono,R-VIO,ORB_SLAM3)and GVIO algorithms(GNSS-MSCKF,VINS-Fusion).The results demonstrate that our algorithm is more robust than other compared algorithms,showing a competitive position accuracy and computational efciency.

关键词： Sensor fusion Visual-inertial odometry Motion manifold constraint

Volume change behavior of unsaturated soils under non-isothermal conditions

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Chinese Science Bulletin 2011年第23期56卷 2495-2504页

作者： CAI guoqing ZHAO ChengGang liu Yan LI Jian Department of Geotechnical and Geoenvironmental Engineering School of Civil Engineering and Architecture Beijing Jiaotong UniversityBeijing 100044 China

With the development of modern geotechnical engineering practices such as the construction of high level radioactive waste repositories, exploitation and utilization of geothermal resources, energy-saving buildings and underground storage of CO 2 , research into the influence of temperature on the basic mechanical properties of unsaturated soils has become an important issue internationally. By using the work expression and considering the influence of temperature on the basic properties of unsaturated soils, the average soil skeleton stress, modified suction and temperature were selected as state variables of generalized forces in thermodynamics and the soil skeleton strain, saturation and entropy were chosen as state variables of generalized flows conjugate to the variables of generalized forces. Based on the nonlinear multi-field coupled model and by using existing experimental results, an elastic-plastic constitutive model of unsaturated soils under non-isothermal conditions was developed to analyze the influence of temperature on the deformation properties of unsaturated soils. The model was used to predict and analyze the influence of suction and temperature on the deformation properties of unsaturated soils under isotropic conditions, and was successfully verified using experimental results.

关键词：非饱和土非等温条件高放射性废物处置库弹塑性本构模型行为体积状态变量耦合模型