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Integral precession calibration method of PIGA on linear vibration table

Chinese Journal of Aeronautics 2024年第3期37卷 219-236页

作者： Chuang SUN shun-qing ren Jun-wei CAO Ru HUO Department of Automation Tsinghua UniversityBeijing 100084China School of Astronautics Harbin Institute of TechnologyHarbin 150001China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China Faculty of Information technology Beijing University of TechnologyBeijing 100124China

Linear vibration table can provide harmonic accelerations to excite the nonlinear error terms of Pendulous Integrating Gyro Accelerometer(PIGA).Integral precession calibration method is proposed to calibrate PIGA on a linear vibration table in this *** on the precise expressions of PIGA’s inputs,the error calibration model of PIGA is *** angular velocity errors of PIGA are suppressed by integer periodic precession and the errors caused by non-integer periods vibrating are *** complete calibration process,including planning,preparation,PIGA testing,and coefficient identification,is designed to optimize the test operations and evaluate the calibration *** effect of the main errors on calibration uncertainty is analyzed and the relative sensitivity function is proposed to further optimize the test *** and simulation results verify that the proposed 10-position calibration method can improve calibration uncertainties after compensating for the related *** order of calibration uncertainties of the second-and third-order coefficients are decreased to 10^(-8)(rad.s^(-1))/g^(2)and 10^(-8)(rad.s^(-1))/g3,*** with the other two classical calibration methods,the calibration uncertainties of PIGA’s nonlinear error coefficients can be effectively reduced and the proportional residual errors are decreased less than 3×10-6(rad.s^(-1))/g by using the proposed calibration method.

关键词： PIGA Linear vibration table Vibration measurement Calibration Error analysis Uncertainty analysis

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Working Principle and Error Analysis for Hemispherical Resonator Gyro under Force-rebalance Mode

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 75-80页

作者： Hong-Bo Zhao shun-qing ren Space Control and Inertial Technology Research Center Harbin Institute of Technology

The two control methods, namely the general-control and the quadrature-control modes for HRG under force-rebalance mode were introduced firstly. Then the azimuth of antinode on the hemispherical resonator was deduced. The dynamics equations of resonator under the nonuniformity of density distribution were established by way of Bubonov-Galerkin method which is commonly used for solution of differential equations, and the state equation was established through the dynamics equations. The analytic solutions of the vibration displacement and the velocity were achieved by solving the state equation, and then the ratio of rebalance excitation to primary excitation was derived under the two working modes, thus the estimation of input angular rate of HRG were obtained. By comparing and calculating these two modes, the error caused by resonator's machining defects can be greatly inhibited under quadrature-control, and the fourth harmonic density error's tolerance were calculated to ensure the accuracy of HRG under these two modes.

关键词： hemispherical resonator gyro force-rebalance mode quadrature-control density distribution nonuniformity

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The grafting PET and PVA fibers coated with soybean lecithin and their blood-compatibility properties

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Chinese Journal of Biomedical Engineering(English Edition) 2002年第2期11卷 72-75页

作者： TANG shun qing, ZHOU Chang ren Biomedical Engineering Institute, Jinan University, Guangzhou,510632,China

the composites of grafting polystyrene polyvinyl acetate (PVA) or polyethylene terephthalate (PET) coated with soybean lecithin, are obtained. Results of grafting experiments show that the grafting ratio on the surface of the fibers is low when the grafting polymer chain is not cross linked. Under scanning electron microscope (SEM), it is discovered that there is no different morphology between the raw fibers and their being coated with soybean lecithin. The composites exhibit a good stability of soybean lecithin layer, and better anti coagulant property than the sulfonated grafting fibers or raw fibers.

关键词： soybean lecithin composite PET fiber blood compatibility properties

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离心机误差对陀螺加速度计误差模型系数标定精度的影响(英文)

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机床与液压 2014年第12期42卷 6-12页

作者：王世明任顺清哈尔滨工业大学空间控制与惯性技术中心哈尔滨150080

为了研究精密离心机自身误差对陀螺加速度计模型系数标定精度的影响,分析了离心机各个误差源,从输入比力和相对惯性空间角速率两个方面讨论了离心机误差源对加速度计参数标定的精度影响,给出了被试加速度计输入加速度和角速度的精确表... 详细信息

为了研究精密离心机自身误差对陀螺加速度计模型系数标定精度的影响,分析了离心机各个误差源,从输入比力和相对惯性空间角速率两个方面讨论了离心机误差源对加速度计参数标定的精度影响,给出了被试加速度计输入加速度和角速度的精确表达式。应用最小二乘法对误差模型参数进行辨识,且计算了在各误差源作用下对于参数辨识精度的影响程度。根据仿真结果,找出了某些离心机误差对加速度计误差系数标定的影响关系,为按照加速度计的标定精度来确定离心机的精度打下了理论基础。

关键词：精密离心机陀螺加速度计输入比力齐次变换误差模型系数

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On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 127-136页

作者： Rui Chen shun-qing Shen Department of Physics The University of Hong KongHong Kong 999077China Department of Physics Hubei UniversityWuhan 430062China

In topological insulators,massive surface states resulting from local symmetry breaking were thought to exhibit a half-quantized Hall conductance,obtained from the low-energy effective model in an infinite Brillouin *** a lattice model,the surface band is composed of a combination of surface states and bulk *** massive surface states alone may not be enough to support an exact one-half quantized surface Hall conductance in a finite Brillouin zone and the whole surface band always gives an integer quantized Hall conductance as enforced by the TKNN *** explore this,we investigate the band structures of a lattice model describing the magnetic topological insulator film that supports the axion insulator,Chern insulator,and semi-magnetic topological insulator *** reveal that the gapped and gapless surface bands in the three phases are characterized by an integer-quantized Hall conductance and a half-quantized Hall conductance,*** propose an effective model to describe the three phases and show that the low-energy dispersion of the surface bands inherits from the surface Dirac *** gapped surface band manifests a nearly half-quantized Hall conductance at low energy near the center of Brillouin zone,but is compensated by another nearly half-quantized Hall conductance at high energy near the boundary of Brillouin zone because a single band can only have an integer-quantized Hall *** gapless band hosts a zero Hall conductance at low energy but is compensated by another half-quantized Hall conductance at high energy,and thus the half-quantized Hall conductance can only originate from the gapless ***,we calculate the layer-resolved Hall conductance of the *** conclusion suggests that the individual gapped surface band alone does not support the half-quantized surface Hall effect in a lattice model.

关键词： magnetic topological insulator Dirac equation half-quantized Hall conductance

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On the consistency of two-phase local/nonlocal piezoelectric integral model

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Applied Mathematics and Mechanics(English Edition) 2021年第11期42卷 1581-1598页

作者： Yanming ren Hai qing State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this paper,we propose general strain-and stress-driven two-phase local/nonlocal piezoelectric integral models,which can distinguish the difference of nonlocal effects on the elastic and piezoelectric behaviors of *** nonlocal piezoelectric model is transformed from integral to an equivalent differential form with four constitutive boundary conditions due to the difficulty in solving intergro-differential equations *** nonlocal piezoelectric integral models are used to model the static bending of the Euler-Bernoulli piezoelectric beam on the assumption that the nonlocal elastic and piezoelectric parameters are coincident with each *** governing differential equations as well as constitutive and standard boundary conditions are *** is found that purely strain-and stress-driven nonlocal piezoelectric integral models are ill-posed,because the total number of differential orders for governing equations is less than that of boundary ***,the traditional nonlocal piezoelectric differential model would lead to inconsistent bending response for Euler-Bernoulli piezoelectric beam under different boundary and loading *** nominal variables are introduced to normalize the governing equations and boundary conditions,and the general differential quadrature method(GDQM)is used to obtain the numerical *** results from current models are validated against results in the *** is clearly established that a consistent softening and toughening effects can be obtained for static bending of the Euler-Bernoulli beam based on the general strain-and stress-driven local/nonlocal piezoelectric integral models,respectively.

关键词： nonlocal piezoelectric integral model softening effect toughening effect general differential quadrature method(GDQM)

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The family of topological phases in condensed matter

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National Science Review 2014年第1期1卷 49-59页

作者： shun-qing Shen Department of Physics The University of Hong Kong

he discovery of topological insulators and superconductors is an important advance in condensed mater *** phases relect global properties of the quantum states in materials,and the boundary states are the characteristic of the *** phases constitute a new branch in condensed mater *** a historic development is briely introduced,and the known family of phases in condensed mater are summarized.

关键词： topological insulator quantum spin Hall efect quantum Hall efect topological superconductor Dirac equation

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Yrast Bands Calculation for Odd-Odd Nuclei ^(160)Ho, ^(162)Tm and ^(164)Tm

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Chinese Physics Letters 1996年第7期13卷 504-507页

作者： ZHU shun-quan ZHENG ren-rong Department of Physics Southwest Normal UniversityChongqing 630715

In this paper,the axial symmetry rotor plus quasiparticle model is generalized from odd nuclei to odd-odd *** spectra of yrast bands for nuclei ^(160)Ho,^(162)Tm and ^(164)Tm are calculated by using the *** inversions in these three nuclei are reproduced,and one possible signature inversion mechanism connected with the calculation is also discussed.

关键词： method symmetry

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All types of base conversions allowed by base editors

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Science China(Life Sciences) 2024年第2期67卷 431-433页

作者： shun-qing Liang Wen Xue RNA Therapeutics Institute UMass Chan Medical SchoolWorcester 01655USA Department of Molecular Cell and Cancer BiologyUMass Chan Medical SchoolWorcester 01655USA Department of Molecular Medicine UMass Chan Medical SchoolWorcester 01655USA Li Weibo Institute for Rare Diseases Research UMass Chan Medical SchoolWorcester 01655USA

Base editors(BEs) hold great promise as tools for introducing single-base-pair changes in both basic research and therapeutic applications(Rees and Liu,2018).Base editors are composed of a Cas9 nickase fused to a DNA-modifying enzyme,which chemically modifies nucleobases within a specific targeting window near the Cas9-binding site.

关键词： base bases allowed

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Diffusion tensor interpolation profile control using non-uniform motion on a Riemannian geodesic

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Journal of Zhejiang University-Science C(Computers and Electronics) 2012年第2期13卷 90-98页

作者： Chang-II SON shun-ren XIA MOE Key Laboratory of Biomedical Engineering Zhejiang UniversityHangzhou 310027China Department of Electronics Kim Chaek University of TechnologyPyongyang 104919DPR of Korea

Tensor interpolation is a key step in the processing algorithms of diffusion tensor imaging (DTI), such as registration and tractography. The diffusion tensor (DT) in biological tissues is assumed to be positive definite. However, the tensor interpolations in most clinical applications have used a Euclidian scheme that does not take this assumption into account. Several Rie-mannian schemes were developed to overcome this limitation. Although each of the Riemannian schemes uses different metrics, they all result in a ‘fixed’ interpolation profile that cannot adapt to a variety of diffusion patterns in biological tissues. In this paper, we propose a DT interpolation scheme to control the interpolation profile, and explore its feasibility in clinical applications. The profile controllability comes from the non-uniform motion of interpolation on the Riemannian geodesic. The interpolation experiment with medical DTI data shows that the profile control improves the interpolation quality by assessing the reconstruction errors with the determinant error, Euclidean norm, and Riemannian norm.

关键词： Diffusion tensor (DT) DT imaging (DTI) DT interpolation Interpolation profile control Riemannian geodesic

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