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Validating global hydrological models by ground and space gravimetry

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chinese Science Bulletin 2009年第9期54卷 1534-1542页

作者： ZHOU JiangCun1,2.3. SUN HePing1,2.& XU JianQiao1,2.1 Institute of {3. and geophysics, {2. academy of Sciences, wuhan 4.0077, china 2.key laboratory of dynamic {3., {2. academy of Sciences, wuhan 4.0077, china 3.graduate University of {2. academy of Sciences, beijing 10004., china Institute of geodesy and geophysics Chinese Academy of Sciences Wuhan 430077 China key laboratory of {2. {3. Chinese Academy of Sciences Wuhan 430077 China graduate University of chinese {2. of Sciences Beijing 100049 China

The long-term continuous gravity observations obtained by the superconducting gravimeters (SG) at seven globally-distributed stations are comprehensively analyzed. After removing the signals related to the Earth's tides and variations in the Earth's rotation, the gravity residuals are used to describe the seasonal fluctuations in gravity field. Meanwhile, the gravity changes due to the air pressure loading are theoretically modeled from the measurements of the local air pressure, and those due to land water and nontidal ocean loading are also calculated according to the corresponding numerical models. The numerical results show that the gravity changes due to both the air pressure and land water loading are as large as 100×10-9 m s-2.in magnitude, and about 10×10-9 m s-2.for those due to the nontidal ocean loading in the coastal area. On the other hand, the monthly-averaged gravity variations over the area surrounding the stations are derived from the spherical harmonic coefficients of the GRACE-recovered gravity fields, by using Gaussian smoothing technique in which the radius is set to be 600 km. Com-pared the land water induced gravity variations, the SG observations after removal of tides, polar mo-tion effects, air pressure and nontidal ocean loading effects and the GRACE-derived gravity variations with each other, it is inferred that both the ground- and space-based gravity observations can effec-tively detect the seasonal gravity variations with a magnitude of 100×10-9 m s-2.induced by the land water loading. This implies that high precision gravimetry is an effective technique to validate the re-liabilities of the hydrological models.

关键词：重力测量水文模型模型验证和空间地面重力变化季节性波动空气压力

The diurnal variations, semiannual and winter anomalies of the ionospheric TEC based on GPS data in china

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Progress in Natural Science:Materials International 2005年第1期 57-61页

作者： HUO Xingliang 1,2.*, YUAN Yunbin 1, OU Jikun 1, WEN Debao 1,2.and LUO Xiaowen 1,2.1. {3. laboratory of {2. geodesy, Institute of geodesy and geophysics, chinese academy of Sciences, wuhan 4.0077, china 2. graduate school of chinese academy of Sciences, beijing 10003., china) key laboratory of {2. {3.，Institute of {3. and geophysics，chinese academy of Sciences，wuhan 4.0077，china graduate school of {2. {3. of Sciences，beijing 10003.，china key laboratory of {2. {3.，Institute of {3. and geophysics，chinese academy of Sciences，wuhan 4.0077，china

With the spherical harmonic (SH) function model and the dual frequency GPS P code phase data from the Crustal Movement Observation Network of china (CMONOC) during the period from year 2.00 to 2.02. time series of total electron content (TEC) in the area of china is calculated. The diurnal variations, semiannual, and winter anomalies of the ionosphere in the area of china are analyzed and discussed, especially according to the results of year 2.01.

关键词： Global Positioning System spherical harmonic function model total electron content semiannual anomaly winter anomaly.

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轮式移动机器人沙地行驶控制建模与仿真研究

系统仿真学报 2008年第18期20卷 5035-5039页

作者：谷侃锋赵明扬中国科学院沈阳自动化研究所沈阳现代装备研究设计中心

结合车轮沙土相互作用的力学分析,研究解决轮式移动机器人沙地行驶车轮过度滑转下陷问题。考虑纵列式重复通过车轮沙土力学参数的修正,建立六轮式沙地移动机器人的动力学模型,以车轮滑转率为状态变量,设计了移动机器人沙地行驶的滑模驱... 详细信息

结合车轮沙土相互作用的力学分析,研究解决轮式移动机器人沙地行驶车轮过度滑转下陷问题。考虑纵列式重复通过车轮沙土力学参数的修正,建立六轮式沙地移动机器人的动力学模型,以车轮滑转率为状态变量,设计了移动机器人沙地行驶的滑模驱动控制器跟踪车轮期望滑转率。MATLAB/Simulink仿真结果表明,采用该控制器可以较快地跟踪期望滑转率,有效地限制机器人车轮的滑转,避免车轮的过度下陷。

关键词：移动机器人车轮下陷滑转率沙地滑模控制 Simulink仿真

Partial continuation model and its application in mitigating systematic errors of double-differenced GPS measurements

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Progress in Natural Science:Materials International 2005年第3期 54-59页

作者： GUO Jianfeng 1,2.ˇˇ ,OU Jikun 1 and REN Chao 1 (1.key laboratory of Geo{2.s,Institute of geodesy and geophysics,chinese academy of Sciences,wuhan4.0077,china 2.graduate {13. of the chinese academy of Sciences,beijing10003.,china) key laboratory of Geo{2.s，Institute of {3. and geophysics，chinese academy of Sciences，wuhan 4.0077，china graduate school of the {2. {3. of Sciences，beijing 10003.，china key laboratory of Geo{2.s，Institute of {3. and geophysics，chinese academy of Sciences，wuhan 4.0077，china

Based on the so-called partial continuation model with exact finite measurements,a new stochastic assessment procedure is *** every satellite pair,the temporal correlation coefficient is estimated using the original double-differenced(DD)GPS *** then,the Durbin-Watson test is applied to test specific hypothesis on the temporal correlation *** the test is not significant with a certain significant level,a data transformation is *** transformed measurements are free of time *** purpose of illustration,two static GPS baseline data sets are analyzed in *** experimental results demonstrate that the proposed procedure can mitigate effectively the impact of systematic errors on DD GPS measurements.

关键词： partial continuation model systematic errors GPS double-differenced measurements.

Disposable Electrochemical Biosensor for Amperometric Measurement of β-hydroxybutyrate and Total Cholesterol

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稀有金属材料与工程 2006年第S3期 305-308页

作者： Huaqing Li~(1,2. Li Wang~1 Nenggao Rao~1 Dafu Cui~1 Xinxia Cai~(1,2. (1.State key {3. of Transducer Technology,Institute of Electronics,{2. academy of Sciences,beijing 100080,china) (2.graduate school of {2. academy of Science,beijing 100080,china)

A new type of disposable thin-film amperometric biosensor has been developed for measurement ofβ-hydroxybutyrate and total cholesterol in *** biosensor consists of two plain gold electrodes mounted on a Polyethylene terephthalate （PET） *** reagent solution contains bienzymes （cholesterol oxidase and cholesterol esterase for total cholesterol,β-hydroxybutyrate dehydrogenase and diaphorase forβ-hydroxybutyrate respectively） with mediator （ferricyanide） were absorption at the surface of electrodes coated by electrodepositing platinum *** presence of the mediator lowers the applied potential and eliminates the interference from other oxidizable species enhancing the sensitivity and selectivity of the biosensor without modifying the dynamic parameters of the *** enzymes stably retains in the matrices of platinum black film improving the performance of the mediated *** linearity is observed in the concentration range from 1.0×10-4to 1.0×10-2.M and 1.0×10-4mM to 4.99×10-3.M with sensitivity of 1.958μA/mM and 2.447μA/mM *** optimized biosensor exhibits excellent reproducibility and stability retaining more than 90% of its original activity over a period of one *** simple operation of the biosensor mass-produced at low cost is expected to find clinical application and homecare.

关键词： amperometric β-Hydroxybutyrate total cholesterol ferricyanide platinum black

A Self-consistent Calculation and an Anisotropic Wavelength Cut off Energy of Spin-wave Spectrumin Magnetic Tunnel Junctions

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Journal of Materials Science & Technology 2001年第2期17卷 197-202页

作者： Xiufeng HAN State key laboratory of Magnetism, Institute of Physics, {2. {3. of Sciences, beijing 100080, china Terunobu Miyazaki Department of Applied Physics, graduate school of Engineering, Tohoku University, Aoba-yama 08, Sendai 980-8579, Japa chinese Acad Sci Inst Phys State Key Lab Magnetism Beijing 100080 Peoples R China Tohoku Univ Grad Sch Engn Dept Appl Phys Sendai Miyagi 9808579 Japan

Temperature dependence of tunnel magnetoresistance (TMR) ratio, resistance, and coercivity from 4.2.K to room temperature (RT), applied de bias voltage dependence of the TMR ratio and resistances at 4.2.K and RT, tunnel current I and dynamic conductance dI/dV as functions of the de bias voltage at 4.2.K, and inelastic electron tunneling (IET) spectroscopy, d(2.I/dV(2. versus V, at 4.2.K for a tunnel junction of Ta(5 nm)/Ni79Fe2.(2. nm)/Ir2.Mn78(12.nm)/Co75Fe2.(4 nm)/Al(0.8 nm)-oxide/Co75Fe2.(4 nm)/Ni79Fe2.(2. nm)/Ta(5 nm) were systematically investigated. High TMR ratio of 59.2. at 4.2.K and 41.3. at RT were observed for this junction after annealing at 2.5 degreesC for an hour. The temperature dependence of TMR ratio and resistances from 4.2.to 3.0 K at 1.0 mV bias and the de bias voltage dependence of TMR ratio at 4.2.K from 0 to 80 mV can be evaluated by a comparison of self-consistent calculations with the experimental data based on the magnon-assisted inelastic excitation model and theory. An anisotropic wavelength cutoff energy of spin-wave spectrum in magnetic tunnel junctions (MTJs) was suggested, which is necessary for self-consistent calculations, based on a series of IET spectra observed in the MTJs.

关键词： off TMR A Self-consistent Calculation and an Anisotropic Wavelength Cut Energy of Spin-wave Spectrumin Magnetic Tunnel Junctions wave Figure than

dynamic CHANGES OF THE WETLAND AND ITS DRIVING FORCES IN FUJIN REGION IN SANJIANG PLAIN,china

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湿地科学 2005年第3期3卷 176-182页

作者： WANG Zhi-Qiang~1,2. CHEN Ming~1,2.WANG Dan-Dan~1,2., ZHANG Bai~1,ZHANG Shu-Qing~1(1. Northeast Institute of Geography and Agricultural Ecology, the {3. academy of Sciences,Changchun Jilin 13.012.{2. 2. graduate school of {3. academy of Sciences, beijing 10003.,{2. ) Northeast Institute of Geography and Agricultural Ecology the Chinese Academy of SciencesChangchun Jilin 130012China graduate school of {2. {3. of Sciences Beijing 100039China Northeast Institute of Geography and Agricultural Ecology the Chinese Academy of SciencesChangchun Jilin 130012China

Wetland is a kind of key natural resources. However, the wetlands have been shrinking rapidly in Sangjiang Plain and its functions have been degrading. These all hold back the sustainable development of human communities, and lead to great change in the land use /cover (LUCC), consequently caused global changes in climate, water cycling, etc.. Taken Fujin region as a case study, spatial and temporal dynamic processes of wetland and its driving forces were analyzed from 1954 to 2.00 in this paper. It showed that the wetlands had been reduced from 52.104 ha to 11×104 ha in areas during the nearly 50 years . The percentage of wetland areas reduced from 61.2.% to 12.3.%. On the other hand, cultivated land increased from 2.×104 ha to 60×104 ha in areas. The percentage of the areas increased from 2..3.% to 70.45%. Further quantitative analysis of the wetland landscape conversion characteristics and the correlation analysis between the change of wetland areas and population increase were made. The results showed that 40×104 ha wetlands had been converted to cultivated land within half of a century; the correlation between the rate of wetland loss and that of population increased is nearly -0.92.. So it was concluded that the main driving force of wetland shrinkage in Fujin region was the colonization of human being.

关键词：湿地动态变化三江平原生态系统生态环境

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模拟研究卫-卫跟踪中星间隔的选择问题

天文学报 2005年第1期46卷 62-69页

作者：周旭华吴斌许厚泽彭碧波中国科学院测量与地球物理研究所动力大地测量重点实验室

从两个方面讨论了低轨卫星在做卫-卫跟踪(SST)观测时,星间隔的选择问题. 1)用地球重力位系数作为扰动量,比较该扰动引起的不同间隔的SST星间距离和速度变化大小. 2.用随机误差为1μm／s的星间速度变化作为模拟观测量,恢复不同间隔的 ... 详细信息

从两个方面讨论了低轨卫星在做卫-卫跟踪(SST)观测时,星间隔的选择问题. 1)用地球重力位系数作为扰动量,比较该扰动引起的不同间隔的SST星间距离和速度变化大小. 2.用随机误差为1μm／s的星间速度变化作为模拟观测量,恢复不同间隔的地球重力位系数,并做精度评估.两种结果表明,适当增大SST间隔对求解重力场有利, 但无限制增大无实际意义,对于选定高度为42. km卫星,在作SST观测时,星间隔不宜超过690km.此模拟方法及结果对我国确定重力卫星指标有着重要意义.

关键词： SST 重力位地球模拟观测重力卫星重力场低轨卫星间隔扰动系数

水田和旱地土壤有机碳矿化规律及矿化量差异研究

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土壤通报 2009年第6期40卷 1325-1329页

作者：郝瑞军李忠佩车玉萍方海兰中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室江苏南京210008 中国科学院研究生院北京100049 上海市同林科学研究所上海200232

水田和旱地是农田土壤的主要利用方式,对有机碳的稳定机制和矿化规律具有重要影响。本研究通过室内培养试验观测了水田、旱地土壤有机碳的矿化动态,并比较了两者之间有机碳矿化量的差异。结果表明,水田、旱地土壤有机碳矿化规律均表现... 详细信息

水田和旱地是农田土壤的主要利用方式,对有机碳的稳定机制和矿化规律具有重要影响。本研究通过室内培养试验观测了水田、旱地土壤有机碳的矿化动态,并比较了两者之间有机碳矿化量的差异。结果表明,水田、旱地土壤有机碳矿化规律均表现为培养前期快速下降,培养后期保持相对稳定的趋势,符合对数关系。但整个培养期内,水田土壤有机碳矿化速率比旱地土壤平均高2..09%,大小幅度变化在4.48%～48.40%之间,累计矿化量高4.2.%～48.40%,且有机碳矿化量差异主要集中在培养前期,随着培养时间的延长而不断缩小。统计结果表明,供试水田、旱地土壤有机碳矿化速率主要受有机碳(SOC)、微生物生物量碳(MBC)及水溶性有机碳(DOC)含量影响,相关系数分别为0.948、0.745、0.763.

关键词：水田旱地土壤有机碳矿化差异