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Combined adjustment project of national astronomical geodetic networks and 2.00' national GPS control network

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Progress in Natural Science:Materials International 2005年第5期15卷 435-441页

作者： YANG Yuanxi1*, ZHA Ming2. SONG Lijie3. WEI Ziqing1, WANG Zhouping2. OUYANG Guichong2. XU Bilin2. WU Xiaoping3.and WANG Junqin4(1. Xi'an Research Institute of {2. and mapping, Xi'an 710054, china 2. Xi'an Informational and Technical Center of {2. and mapping, Xi'an 710054, china 3. zhengzhou Institute of {2. and mapping,{12. 4. The First {2. Team of Tianjin, Tianjin 3.0140, china) Xian Research Institute of surveying and mapping Xi''an 710054 China Xi''an Informational and Technical Center of surveying and mapping Xi''an 710054 China zhengzhou Institute of surveying and {2. Zhengzhou 450052 China

The combined adjustment project of the nationwide astronomical geodetic networks and 2.00' national GPS control network involve 48519 terrestrial observational stations and 2.66 GPS observational stations. In the terrestrial network, 2.107 stations are height fixed and 2.0}12.stations are in three dimensions. 440793.terrestrial observations and 183.68 unknowns are involved in the adjustment. The three-dimensional observational models for the adjustment have been established. The crustal deformation influences and corrections are researched. Fast methods of solving partitioned adjustment for super large-scale geodetic network have been studied. The standard deviations of three-dimensional coordinates for all stations are evaluated. As a result of the combined adjustment, a unified national geodetic network with nearly 50000 stations is established, the high accurate three-dimensional geocentric coordinates are obtained. The standard deviation for geoid is averagely 0.2.m, for vertical deflection is about 1.5″, for the horizontal position is about 0.12.m, for the geodetic height is about 0.14 m, and for the three-dimensional position is averagely 0.3.m.

关键词： astronomical geodetic network GPS network combined adjustment datum geocentric coordinates.

Silicon nanoporous pillar array and its surface copper deposition

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Chinese Science Bulletin 2005年第14期50卷 1424-1428页

作者： FU Xiaonan1,2.3. CHAI Huadou1,2.& LI Xinjian1,2.1. Department of Physics, zhengzhou University,{2. 2. Key Laboratory of Material Physics (zhengzhou University), Ministry of Education,{2. 3. Department of Mathematics and Physics, Henan University of Tech- nology,{2. Department of Physics Zhengzhou University Zhengzhou 450052 China Key Laboratory of Material Physics (zhengzhou University) Ministry of Education Zhengzhou 450052 China Department of Mathematics and Physics Henan University of Technology Zhengzhou 450052 China

Silicon nanoporous pillar array (Si-NPA) has been prepared by a hydrothermal etching technique. Using Si-NPA as substrate, a Cu/Si-NPA nanocomposite thin film has been obtained with immersion plating method. Morpho- logical and structural analysis indicates that Si-NPA is a typical structural composite system characterized by a triple hierarchical structure, i. e. the array of micron-sized silicon pillars, the nanopores densely distributed on the surface of the pillars, and the silicon nanocrystallites that constitute the pore walls. Cu/Si-NPA inherits the morphological character- istics of Si-NPA. The compactability of the deposited copper nanoparticles varies alternatively with the local geometrical features of Si-NPA and forms a quasi-periodical pattern. Such an experimental phenomenon is attributed to the veloc- ity dependence of the copper deposition upon the local geo- metrical features of Si-NPA. These results indicate that Si-NPA might be used as an ideal template for preparing specially patterned, structured or functionalized metal/ sili- con nanocomposite systems.

关键词：硅元素薄膜蚀刻技术电镀技术

A new learning statistic for adaptive filter based on predicted residuals

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Progress in Natural Science:Materials International 2006年第8期16卷 833-837页

作者： YANG Yuanxi and GAO Weiguang (Xi'an Research Institute of surveying and mapping, Xi'an710054, {2. Institute of surveying and mapping, University of Information Engineering, zhengzhou 450052. china) Xi''an Research Institute of surveying and mapping Xi''an 710054 China. Institute of surveying and mapping University of Information Engineering Zhengzhou 450052 China

A key problem for an adaptive filter is to establish a suitable adaptive factor for balancing the contributions of the measurements and the predicted state information from some kinematic models. The reasonable adaptive factor needs a reliable learning statistics to judge the state kinematic model errors. After analyzing the existing two kinds of learning statistics based on the state discrepancy and variance component ratio, a new learning statistic based on predicted residuals is set up, which is different from the exiting learning statistics. The new learning statistic does not need to estimate the kinemetic state parameters before the filtering process, Of course, it does not need necessary measurements to estimate state parameters for all observation epochs. The new learning statistic can be applied together with the learning factor constructed by the state discrepancy. The advantages and shortcomings of the new learning factor are analyzed, and an example is given.

关键词： adaptive factor adaptive filter kinematic model predicted residual.

Baseline design of the KunLun Turbulence Profiler instrument

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Astronomical Techniques and Instruments 2024年第4期1卷 218-226页

作者： Xiaohui Guo Yi Hu Jing Li Xu Yang zhengzhou Yan School of Physics&Astronomy China West Normal UniversityNanchong 637002China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 101408China

Adaptive optics systems are the most powerful tools to counteract the image blurring caused by atmospheric turbulence,allowing ground-based telescopes to capture high-resolution images.A critical parameter influencing adaptive optics system performance is the atmospheric refractive index structure constant,C_(n)^(2.,which characterizes the intensity of atmospheric optical turbulence as a function of *** its simplicity,the lunar scintillometer is the preferred method for detecting atmospheric turbulence in challenging environments like Dome A in Antarctica,where sites are still in the developmental stages and local environmental conditions are extremely ***,optimizing the performance of such instruments requires carefully determining the baseline configuration of photon sensors according to each site's specific optical turbulence profile *** study uses a Monte Carlo method to identify the optimal configuration for the KunLun Turbulence Profiler(KLTP),an instrument comparable to the lunar scintillometer,developed for use at Dome *** conducted using the obtained optimal baseline configuration recovered three different model optical turbulence profiles,demonstrating the effectiveness of our method in obtaining an optimal baseline *** approach can be easily applied to baseline design for similar turbulence profilers at other sites.

关键词： KunLun Turbulence Profiler Monte Carlo Simulation Turbulence profile

The GPS-gravimetry boundary value problem

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Science china Earth Sciences 2005年第3期48卷 398-405页

作者： YU Jinhai1,2.& ZHANG Chuanding2.1. Institute of Geodesy and Geophysics of Chinese Academy of Sciences, Wuhan 43.077, china 2. {2. Information Engineering University, zhengzhou 450052. china Institute of Geodesy and Geophysics of Chinese Academy of Sciences Wuhan China zhengzhou Information Engineering University Zhengzhou China

How to determine the earth’s external gravity field with the accuracy of O(T2. by making use of GPS data and gravity values measured on the earth’s surface is dealt with in this paper. There are two main steps: to extend these measured values on the earth’s surface onto the reference ellipsoid at first and then to seek for the integral solution of the external Neumann problem outside the ellipsoid. In addition, the corresponding judging criteria of accuracy to solve the GPS-gravity boundary value problem are established. The integral solution given in the paper not only contains all frequency-spectral information of the gravity field with the accuracy of O(T 2., but is also easily computed. In fact, the solution has great significance for both theory and prac- tice.

关键词： Neumann boundary value problem, integral solution, gravity disturbance.

The gravitational gradient tensor’s invariants and the related boundary conditions

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Science china Earth Sciences 2010年第5期53卷 781-790页

作者： YU JinHai1,2.3.& ZHAO DongMing4 1 College of Earth Science, Graduate University of Chinese Academy of Sciences, Beijing 100049, china 2.Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 43.077, china 3.State Key Laboratory of Astronautic Dynamics, Xi’an 710043. china 4 {3. Institute of surveying and mapping, zhengzhou 450052. china College of Earth Science Graduate University of Chinese Academy of Sciences Beijing China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China State Key Laboratory of Astronautic Dynamics Xi’an China zhengzhou Institute of surveying and {2. Zhengzhou China

Here we report new approaches of recovering the Earth gravitational field from GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometric data with the help of the gradient tensor’s invariants. Our results only depend on GOCE satellite’s position and gradiometry, in other words, they are completely independent of the satellite attitude. First, starting from the invariants, linearization models are established, which can be referred as the general boundary conditions on the satellite’s orbit. Then, the spherical approximation expressions for the models are derived, and the corresponding solving methods for them are discussed. Furthermore, considering effects of J2.term, the spherical approximation models are improved so that the accuracies of the boundary conditions can be theoretically raised to O ( J 2.2.T), which is approximately equivalent to O(T2.. Finally, some arithmetic examples are constructed from EGM96 model based on the derived theories, and the computational results illustrate that the spherical models have accuracies of 10-7 and the order recovering the gravitational field can reach up to 2.0, and the models with regard to effect of J2.term have accuracies of 10-8 and the order can reach up to 2.0.

关键词： the Earth’s gravitational field gravitational gravidiometry tensor’s invariant

Explicit Solutions for a (2.1)-Dimensional Toda Lattice with Two Discrete Variables

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Communications in Theoretical Physics 2007年第10期48卷 667-670页

作者： WANG Zheng-Yan YANG Xiao Department of Mathematics,zhengzhou University,zhengzhou {2.{3. Department of Mathematics Zhengzhou University

An integrable(2.1)-dimensional Toda lattice with two discrete variables is investigated again,which isproduced from a compatible condition of the Lax *** Darboux transformation for its spectral problems is *** an appl... 详细信息

关键词： Toda lattice two discrete variables Darboux transformation explicit solution

Effect of Initial Microstructure on Warm Deformation Behavior of 45 Steel

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Journal of Iron and Steel Research International 2012年第8期19卷 75-78页

作者： ZHAO Xin1, YANG Xiao-ling2. JING Tian-fu3.(1. The Sixth Department, zhengzhou Institute of Aeronautics, zhengzhou 450015, Henan, china 2. zhengzhou Zhongxing Basic Constructions Development Co Ltd, zhengzhou 450015, Henan, china 3. State Key Laboratory of Metastable Materials Science and Technology, Qinhuangdao 066004, Hebei, china) The Sixth Department Zhengzhou Institute of Aeronautics Zhengzhou Henan China zhengzhou Zhongxing Basic Constructions Development Co Ltd Zhengzhou Henan China State Key Laboratory of Metastable Materials Science and Technology Qinhuangdao Hebei China

In order to investigate the effect of initial microstructure on warm deformation behavior, some specimens of 45 steel were annealed and some quenched. Then the specimens were isothermally compressed on a Gleeble 3.00 machine. The deformation temperature range was 550 to 700 ℃ and the strain rate range was 0.001 to 0.1 s-1. An optical microscope (OM) and a transmission electron microscope (TEM) were used to study the microstructures. The results show that the microstructure of annealed specimens is ferrite and pearlite and that of quenched specimens is martensite. The flow stress of quenched specimens is higher than that of annealed ones at 550 ℃ when strain rates are greater than 0.001 s-1. However, at 600 to 700 ℃ and strain rate of 0.001 s-1, the whole flow curves of quenched specimens are below that of annealed ones. Under the rest conditions, the flow stress of quenched specimens is higher at the beginning of compression and then the opposite is true after the strain is greater than a critical value. The microstructure examination proves that the tempering and dynamic recrystallization easily occur in the specimens with martensite during warm compression, which results in the above phenomena.

关键词： warm deformation flow stress steel microstructure

A　SUPERLINEARLY　CONVERGENT　GENERALIZED　GRADIENT　PROJECTION　ALGORITHMFOR　LINEARLY　CONSTRAINED　PROBLEMS

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Systems Science and Mathematical Sciences 1995年第4期8卷 299-310页

作者： HE Guoping GAO Ziyou(Institute of Applied Mathematics,Academia Sinica,Beijing 100080,china)ZHU Jianqing (zhengzhou Institute of {2. and {3.,zhengzhou 450052.china) 中科院应用数学所北京解放军郑州测绘学院河南郑州 450052

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关键词： Generalized gradient projection method linearly constrained problem superlinear convergence pivoting operation.