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Pathways of birnessite formation in alkali medium

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Science china Earth Sciences 2005年第9期48卷 1438-1451页

作者： FENG Xionghan1, TAN Wenfeng1, LIU Fan1, HUANG Qiaoyun1 & LIU Xiangwen2.1. College of Resources and Environment, Huazhong Agricultural university, Wuhan 430070, china 2. {2.ing center, china university of Geosciences, Wuhan 430074, china 1. College of Resources and Environment Huazhong Agricultural University 430070 Wuhan China 2. testing center China University of Geosciences 430074 Wuhan China

Birnessite is a common weathering and oxidation product of manganese-bearing rocks. An O2.oxidation procedure of Mn(OH)2.in the alkali medium has been used to synthesize birnessite. Fast and powder X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), energy dispersed X-ray analysis (EDAX), infrared spectroscopy (IR) techniques and chemical composition analysis, Eh-pH equilibrium diagram approaches were employed to investigate the reaction process and pathways of birnessite formation. Results showed that the process of the birnessite formation could be divided into four stages: (1) forma- tion stage for hausmannite and feitknechtite, (2. stage of transformation of hausmannite and feitknechtite to buserite, (3) buserite crystal growing stage, and (4) stage of conversion of buser- ite into birnessite. Mn(OH)2.was mainly present as amorphous state only for a short initial time of oxidation reaction. In the oxidation process, buserite formed following two pathways by recrys- tallization after dissolution of the intermediates, and the transformations of the minerals de- pended on the Eh determined by the dissolved O2.concentration on their surfaces. The results are fundamental in further exploration on the mechanism of birnessite formation in the alkali medium. A great practical significance would also be expected with respect to the areas of mate- rial sciences.

关键词： birnessite, pathway of formation, reaction process, Eh-pH diagram, hausmannite, feitknechtite.

Solvation effects on brain uptakes of isomers of ^(99m)Tc brain imaging agents

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Chinese Science Bulletin 2002年第21期47卷 1786-1791页

作者： JIA Hongmei, MA Xiaohui, WANG Cunxin & LIU Boli1. Department of Chemistry, Beijing Normal university, Beijing 100875, china 2. {2. for Biomedical Engineering, Beijing Polytechnic university, Beijing 10002., china 1. Department of Chemistry Beijing Normal University Beijing 100875 China 2. center for Biomedical Engineering Beijing Polytechnic University Beijing 100022 China

analysis of electrostatic hydration free energies of the isomers of the 99mTc-BAT and 99mTc-DADT complexes is carried out using the computer simulation technique. The results show that not only a correlation exists between the logarithm of the brain uptake and the electrostatic hydration free energy for the isomers of 99mTc-brain radiopharmaceu-ticals, but also a linear relationship exists between the logarithm of the ratio of the brain uptake of the syn isomer to that of the anti one and the difference between the electrostatic hydration free energy of the syn-isomer and that of the anti one. Furthermore, the investigation on the important factors influencing the brain uptakes of 99mTc-radiophar-maceuticals and the reasons of the different biodistribution of the isomers of the 99mTc-complexes is explored at the molecular level. The results may provide a reference for the rational drug design of brain imaging agents.

关键词： 99mTc-brain imaging agent isomer brain uptake electro-static hydration free energy.

Polynomial analysis of canopy spectra and biochemical component content inversion

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Science china Earth Sciences 2005年第10期48卷 1780-1791页

作者： YAN Chunyan1, LIU Qiang1, NIU Zheng1, WANG Jihua2. HUANG Wenjiang2.& LIU Liangyun 2.1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal university, Beijing 100101, china 2. National Engineering Research {2. for Information Technology in Agriculture, Beijing 100089, china State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal university Beijing china National Engineering Research center for Information Technology in Agriculture Beijing china

A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for re-trieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coeffi-cients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a10 and a01 for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE re-spectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

关键词： polynomial expression, canopy spectra, decomposition, biochemical component content, inversion.

Biological networks to the analysis of microarray data

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Progress in Natural Science:Materials International 2006年第12期16卷 1242-1251页

作者： FANG Zhuo~1, LUO Qingming~1**, ZHANG Guoqing~1 and LI Yixue~2.*(1. Hubei Bioinformatics and Molecular Imaging Key Laboratory,Huazhong university of Science and Technology, Wuhan 430074, china 2. Shanghai {2. for Bioinformation and Technology, Shanghai 2.02.5, china) [a]Hubei Bioinformatics and Molecular Imaging Key Laboratory Huazhong University of Science and Technology Wuhan China [b]Shanghai center for Bioinformation and Technology Shanghai China

Microarray technology, which permits rapid and large-scale screening for patterns of gene expressions, usually generates a large amount of data. How to mine the biological meanings under these data is one of the main challenges in bioinformatics. Compared to the pure mathematical techniques, those methods incorporated with some prior biological knowledge generally bring better interpretations. Recently, a new analysis, in which the knowledge of biological networks such as metabolic network and protein interaction network is introduced, is widely applied to microarray data analysis. The microarray data analysis based on biological networks contains two main research aspects: identification of active components in biological networks and assessment of gene sets significance. In this paper, we briefly review the progress of these two categories of analyses, especially some representative methods.

关键词： biological networks microarray data analysis subnetwork gene set.

Dissolution theory of gold in alkaline thiourea solution(Ⅲ) ——Thermodynamics on dissolution of gold in alkaline thiourea solution containing Na _2.O_3

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中国有色金属学会会刊：英文版 1999年第3期9卷 646-650页

作者： Chai Liyuan(柴立元) 1, Masazumi Okido 2.1. Department of Nonferrous Metallurgy, Central South university of Technology, Changsha 410083, P.R.china 2. {2. for Integrated Research of Science and Engineering, Nagoya university,Nagoya 464, Japan 中南工业大学有色冶金系湖南长沙 Nagoya university 日本

The oxidants of gold were investigated in an alkaline thiourea solution containing Na 2.O 3, in which Na 2. 2. 8 is a proper oxidant for dissolving gold because of in such homogeneous sulfur system coexisting complex agent, oxidant and stabilizing agent. The thermodynamic analyses were conducted on the dissolving of gold in the alkaline thiourea solution containing Na 2.O 3 by the oxidants oxygen or Na 2. 2. 8. The results show that the possibility of gold dissolution reduces with increasing pH value, while oxygen acts as oxidant; and when Na 2. 2. 8 acts as the oxidant of gold in the alkaline thiourea solution of pH 12.5, decomposition potential of thiourea decreases from the standard value 0.42.V to -0.32.V, also the dissolution trend of gold enhances with shifting the mix potential of the solution to the positive direction.

关键词： thermodynamic analysis gold dissolution thiourea leaching Document code:A

Kalman filtering for time-delayed linear systems

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Science in china(Series F) 2006年第4期49卷 461-470页

作者： LU Xiao1,2.& WANG Wei1 1. Research center of Information and Control, Dalian university of Technology, Dalian 11602.,{2. 2. Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055,{2. 1. Research center of Information and Control Dalian University of Technology Dalian 116024 China 2. Shenzhen Graduate School Harbin Institute of Technology Shenzhen 518055 China

This paper is to study the linear minimum variance estimation for discretetime systems. A simple approach to the problem is presented by developing re-organized innovation analysis for the systems with instantaneous and double time-delayed measurements. It is shown that the derived estimator involves solving three different standard Kalman filtering with the same dimension as the original system. The obtained results form the basis for solving some complicated problems such as H, fixed-lag smoothing, preview control, H, filtering and control with time delays.

关键词： discrete-time systems delayed measurements innovation analysis Riccati equations.

A new family of windows——convolution windows and their applications

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Science china(Technological Sciences) 2005年第4期48卷 468-480页

作者： ZHANG Jieqiu1,2. LIANG Changhong1 & CHEN Yanpu3 1. Department of Applied Math. & Phys., College of Science, Airforce Engineering university, Xi’an 710051, china 2. National Key Laboratory of Antennas and Microwave Technology, Xidian university, Xi’an 710071, china 3. Computer center, Xi’an Communication College, Xi’an 710106, china 1. Department of Applied Math. & Phys. College of Science Airforce Engineering University 710051 Xi’an China 2. National Key Laboratory of Antennas and Microwave Technology Xidian University 710071 Xi’an China 3. Computer center Xi’an Communication College 710106 Xi’an China

A new family of windows is constructed by convolutions via a few rectangular windows with same time width and is thus referred to as convolution windows. The expressions of the second-order up to the eighth-order convolution windows in both the time and frequency domains are derived. Their applications in high accuracy harmonic analysis of periodic signals are investigated. Comparisons between the proposed windows and some known windows with the same width shows that, when the synchronous deviation of data sampling is slight, the proposed ones have the least effect of spectral leakage. Therefore, the new windows are well suited for high accuracy harmonic analysis and parameter estimation for periodic signals. The error analysis and computer simulations show that the estimation errors, corresponding to frequency, amplitude and phase of every harmonic component of a signal, are proportional to the pth power of the relative frequency deviation in case of the pth-order convolution window is applied to windowing signal of approximately p cycles. By introducing real time adjustment in sampling interval, the proposed algorithm can adaptively trace signal frequency and lead to less sampling synchronous deviation. The proposed approach has the advantages of easy implementation and high measure precision and can be used in harmonic analysis of quasi-periodic signals whose fundamental frequency drifts slowly with time.

关键词： signal processing harmonic analysis window function convolution window synchronous error spoctral leakage

Thermodynamic analysis of the Preparation Process of EB-PVD SiC Coating

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Journal of Wuhan university of Technology(Materials Science) 2009年第3期24卷 363-366页

作者：易剑 School of Mechatronics Engineering Taizhou University Laser Processing center Tianjin Polytechnic University center for Composite Materials Harbin Institute of Technology

The process of preparing SiC coating by electron beam-physical vapor deposition （EB-PVD） was discussed from viewpoint of thermodynamis. Results show that within the temperature range of 2.700-3 300 K, the ratio of SiC in the SiC coating doesn＇t change much and keeps around 0.7. Purity of the as-deposited SiC coating is not high. To improve the purity of the SiC coating, the SiC ingot is required to not be, necessary in full density but be fine-grained.

关键词： thermodynamics SiC coating EB-PVD ratio of SiC purity

Comprehensive evaluation of mechanism of "chimney effect" using principles of magnetism, geochemistry and mineralogy

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Chinese Science Bulletin 1998年第9期43卷 743-748页

作者： LIU Qingsheng 1, CHENG Tongjin 2.and LIU Shugen 3 1. Department of Applied Geophysics, china university of Geosciences, Wuhan 430074, china 2. center of Petroleum Geochemistry, china National Star Petroleum Corporation, Hefei 2.002., china 3. The St Department of Applied Geophysics China University of Geosciences Wuhan China center of Petroleum Geochemistry China National Star Petroleum Corporation Hefei China The State Key Laboratory of Oil/Gas Reservoir Geology and Exploitation of china Chengdu Institute of Technology Chengdu China

Study of forming mechanism of "chimney-effect" (CE) has important significance for basic theory and applications of non-seismic geophysical and geochemical methods locating oil/gas reservoirs. The theoretical basis of comprehensive evaluation of mechanism of CE using principles of magnetism, geochemistry and mineralogy has been reviewed, with the problems to be solved: (ⅰ) study for the relationship between process of oil/gas migration and geochemical field; (ⅱ) analysis of genesis of magnetic, geochemical and mineralogical anomaly; (ⅲ) interpretation of surface soil magnetism and geochemical anomaly combined with seismic data.

关键词： chimney effect (CE) hydrocarbon microseepage oil/gas accumulation.