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Fluorescence fluctuation spectroscopy and its artifacts:simulations and tests

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 336-344页

作者： MENG Fanbo 1., CHEN Bo 1., LIU Guang 1., DING Jianying 1.& MA Hui 2.1.1. Department of Physics and Key Laboratory of Atomic and Molecular Nano Sciences, Ministry of Educa- tion,{1., Beijing 1.0084, china 2. {2. School at shenzhen,{1., shenzhen 51.055, china 1. Department of Physics and Key Laboratory of Atomic and Molecular Nano Sciences Ministry of Education Tsinghua University 100084 Beijing China 2. {1. School at shenzhen Tsinghua University 518055 Shenzhen China

Fluorescence fluctuation spectroscopy (FFS) technique is capable of monitoring changes in concentration, mass, size and structure of fluorescent-labeled bio-molecules in microscopic volume and is suitable for measuring biological interactions in living cells. FFS data may be affected by many experimental factors in complicated biological systems. Using a Monte Carlo approach, we generate fluorescence fluctuation data for different experimental systems. This approach helps to separate the contributions by different experimental factors in a complicated fluorescence fluctuation spectrum. It also helps to validate new theoretical models and new fitting formulations. We describe the algorithm of the simulation program and tests on its statistical performance. The program is then used successfully to study the effects of several experimental factors on FFS detection.

关键词： fluorescence fluctuation spectroscopy, fluorescence correlation spectroscopy, Monte Carlo simulation.

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 {1. of Technology, Dalian 1.602., china 2. {2. graduate School, Harbin Institute of Technology, shenzhen 51.055, china 1. Research Center of Information and Control Dalian University of Technology Dalian 116024 China 2. {1. 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.

Electrochemical Corrosion Behavior of Arc Sprayed Zn and Zn1.Al Coatings in Simulated Salina Soil and Neutral Meadow Soil Solutions

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Journal of Wuhan university of Technology(Materials Science) 2011年第6期26卷 1152-1156页

作者：林碧兰 graduate School at {1. Tsinghua University

Arc sprayed Zn and Zn1.Al coatings were chosen to protect the metal ends of prestressed high-strength concrete （PHC） pipe piles against corrosion of salina soil in northern china and neutral meadow soil in northeast china. The corrosion behavior of the coated Q2.5 steel samples in two simulated soil solutions were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） methods. The experimental results show that the corrosion of the matrix Q2.5 steel in both simulated solutions is remarkably inhibited by Zn and Zn1.Al coatings. The corrosion products on Zn and Zn1.Al are thick, compact, firm and protective. The corrosion current density icorr of both Zn and Zn1.Al-coated samples is decreased evidently with corrosion time, and the charge transfer resistance Rct is increased greatly. The corrosion resistance indexes of Zn and Zn1.Al in simulated neutral meadow soil solution are more outstanding than those in salina soil. The corrosion resistance of Zn1.Al in salina soil is slightly superior to that of Zn. When the sprayed coatings are sealed with epoxy resin, the corrosion resistance of the coatings is further enhanced markedly.

关键词： arc spray coating soil corrosion electrochemical

VEGF-specific siRNAs modified with 2.-deoxy effectively suppress VEGF expression and inhibit growth of nasopharyngeal carcinoma xenograft in a mouse model

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Science china(Life Sciences) 2008年第2期51卷 104-110页

作者： CHEN ShanYi1, GAO GuoFeng1, CHEN Wei1, Lü Qing2. TANG Shen2. HUA Zhong2. YE WenBin2. GU DaYong2. WANG ShaYan1 & ZHANG YaOu2.1 shenzhen People’s Hospital, Clinical Medical College of Jinan university, shenzhen 51802., china 2.Life Science Division, graduate School at shenzhen, tsinghua university, shenzhen 51.055, china 1. shenzhen People’s Hospital Clinical Medical College of Jinan University Shenzhen 518020 China 2. Life Science Division Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China

Vascular endothelial growth factor (VEGF) is up-regulated in the vast majority of human tumors. The up-regulation of VEGF not only plays important roles in tumor angiogenesis, but also provides a target for tumor treatment with small interfering RNA (siRNA) that targets VEGF; however, it is unclear whether a quite high up-regulation of VEGF will affect the efficiency of RNA interference strategies targeting VEGF. A high level expression of VEGF was found in CNE cells from a nasopharyngeal carcinoma cell line. In this study, we investigate whether VEGF-specific siRNAs can effectively suppress VEGF expression in CNE cells, and study the methods for the use of VEGF-specific siRNAs as potential therapeutic agents. CNE cells with high VEGF expression induced by hypoxia were transfected with VEGF-specific siRNAs. The expression of VEGF was effectively suppressed by VEGF-specific siRNAs, measured by ELISA, Western blot analysis and RT-PCR. Furthermore, experiments in nude mice bearing nasopharyngeal carcinoma xenograft were initiated 5 d after injection of CNE cells. VEGF-specific siRNAs were modified with 2.-deoxy, then injected into the tumors, and a liposome-mediated siRNA transfection system and ultrasound exposure were used to help delivery of the siRNAs. Tumor growth was reduced significantly after 3 weeks' treatment. These studies suggest that VEGF-specific siRNAs still can effectively suppress VEGF expression even in tumor cell lines with a relatively high level of VEGF expression, such as CNE, and VEGF-specific siRNAs modified with 2.-deoxy can be used as potential agents for tumor therapy.

关键词： small interfering RNA vascular endothelial growth factor (VEGF) nasopharyngeal carcinoma 2.-deoxy modification ultrasound

Pollution characteristics of atmospheric fine particles and their secondary components in the atmosphere of shenzhen in summer and in winter

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Science china Chemistry 2006年第5期49卷 466-474页

作者： NIU Yuwen1,2.HE Lingyan1,2.HU Min2.ZHANG Jing2.& ZHAO Yunliang2.1. shenzhen graduate School of Peking {2.,shenzhen 51.055,china 2. State Joint Key Laboratory of Environmental Simulation and Pollution Control,College of Environmental Sciences,Peking {2.,Beijing 100871,china 1. shenzhen {1. School of Peking {2. Shenzhen 518055 China 2. State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing 100871 China

Two field measurements for atmospheric fine particles were conducted in Baoan district of shenzhen during the summer and winter in {1.04. Totally 30 sets of {1. h samples were collected, and then the mass concentrations and chemical compositions were determined. The seasonal varia- tions and secondary pollution characteristics of fine particles during the sampling periods were dis-cussed with meteorological factors. The results show that seasonal variations of atmospheric particles are significant in shenzhen. The average mass concentrations of PM{1.5 and PM1. in summer were 35 μg·m-3 and 57 μg·m-3, respectively, and those in winter were 99 μg·m-3 and 1.5 μg·m-3, respec-tively. The concentrations of both PM{1.5 and PM1. in winter increased 1.4% and 1.7%, respectively, compared to those in summer. PM{1.5 accounted for 61. and 75% of PM1. in summer and in winter, respectively, indicating severe fine particle pollution in shenzhen. During the summer and winter sampling periods, the mean OC/EC ratios were 3.4 and 1.6, respectively. The estimated secondary organic carbon (SOC) averagely accounted for 56% and 6% of the total OC in summer and in winter, respectively, which implies a major contribution of SOC to OC in summer. During the continuous high temperature period in summer, both the concentrations and fractions of secondary aerosol compo-nents in PM{1.5 were highly elevated, suggesting severe secondary pollution again. The prevailing wind was from South china Sea in summer, and the air quality was good. The prevailing wind in winter was from china's Mainland to the north, and the polluted air mass led to poor air quality.

关键词： PM2.5, mass concentration, secondary pollution, seasonal variation, shenzhen.

Advances in theory and applications of fuzzy clustering

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Chinese Science Bulletin 2000年第11期45卷 961-970页

作者： GAO Xinbo & XIE Weixin1. Institute of Electronic Engineering, Xidian university, Xi’an 71.071.{1. 2. President office, {2. university, {2. 51.060,{1.. Institute of Electronic Engineering Xidian University Xi’an China President office Shenzhen University Shenzhen China

The summarization and evaluation of the advances in fuzzy clustering theory are made in the aspects including the criterion functions, algorithm implementations, validity measurements and applications. Several importa... 详细信息

关键词： cluster analysis fuzzy clustering cluster validity pattern recognition image processing.

Positioning localities from spatial assertions based on Voronoi neighboring

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Science china(Technological Sciences) 2010年第S1期53卷 143-149页

作者： GONG YongXi 1.2.3,LI GuiCai 1.LIU Yu 2.& YANG Jian 1.1.shenzhen Key Lab of Recycling Economy,Peking university shenzhen graduate School,shenzhen 51.055,china 2.nstitute of Remote Sensing and Geographical Information Systems,Peking university,Beijing 1.0871.china 3College of Urban and Environmental Science,Peking university,Beijing 1.0871.china Peking Univ Shenzhen Grad Sch Shenzhen Key Lab Recycling Econ Shenzhen 518055 Peoples R China Peking Univ Inst Remote Sensing & Geog Informat Syst Beijing 100871 Peoples R China Peking Univ Coll Urban & Environm Sci Beijing 100871 Peoples R China

With the rapid development of Internet,much spatial information contained in non-structured or semi-structured documents is available on the World Wide *** such documents,localities are always textually described using spatial relationships and named places,instead of numerical ***,extracting positional information from locality descriptions is an important *** this paper,we bridge two aspects of locality descriptions,namely generating locality descriptions and positioning localities,and provide a method to compute probability density according to the selection probability of a reference object to describe the position of the target *** operation on uncertainty field is used to deal with locality description involving multiple reference *** metrics are introduced to measure the results of positioning *** choose the mixed selection probability function based on Euclidean distance and Voronoi stolen-area to compute probability density ***,we use three cases to demonstrate the proposed methods.

关键词： geographic information science positioning locality Voronoi neighboring probability density function

Multispectral image edge detection via Clifford gradient

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Science china(Information Sciences) 2012年第2期55卷 260-269页

作者： XU Chen2.LIU Hui1.CAO WenMing1.& FENG JiQiang2.1.ollege of Information Engineering,shenzhen university,shenzhen 51.060,china 2.nstitute of Intelligent Computing Science,shenzhen university,shenzhen 51.060,china 2. Institute of Intelligent Computing Science Shenzhen University Shenzhen 518060 China1. College of Information Engineering Shenzhen University Shenzhen 518060 China

The edge detection of a multispectral image with a mass of image information is theoretically expected to give a more accurate *** algebra is more suitable for processing multidimensional data and expressing the data association than general ***,the basic properties of Clifford algebra are ***,the Clifford algebra description of a multispectral image is ***,a novel multispectral image edge detection algorithm is proposed in terms of the Clifford *** the first two experiments,comparison of the detail achieved by the new algorithm with that from the maximal entropy edge detection algorithm reveals that the edge detection based on Clifford gradient is better at retaining and identifying edge information of the multispectral image than the maximal entropy edge detection *** experiments using tuberculosis CT image show that the new algorithm has clinical value in reducing risk of misdiagnosis.

关键词： multispectral image edge detection Clifford gradient

Research on the method for retrieving soil moisture using thermal inertia model

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Science china Earth Sciences 2006年第5期49卷 539-545页

作者： LIU Zhenhua1.& ZHAO Yingshi2.1. Information College, South{1. Agricultural university, Guangzhou 51.642.{1. 2. graduate university of Chinese Academy of Sciences, Beijing 1.0049,{1. 1. Information College South China Agricultural University Guangzhou 510642 China 2. {1. university of Chinese Academy of Sciences Beijing 100049 China

In order to improve accuracy of soil moisture inversion using remote sensing, a new thermal inertia model is proposed in this paper. The improved model needs only surface maximum temperature as the temperature parameter input instead of input of the surface temperature difference, as well as the surface sensible and latent fluxes are introduced into boundary conditions of thermal conductivity equation. Furthermore, surface soil conductive heat transfer equation of two-layer model is used to solve the soil thermal inertia so that the remote sensing thermal inertia method can be ap- plied to regions with better-covered vegetation, but usually only for the bare areas or worse vegetation covered areas. The model has been tested at several locations in the area of west Inner Mongolia. Comparing the simulation of the new model with the measurements obtained by apparent thermal inertia and by field test, the result shows that the inertia thermal model can be used to estimate soil moisture in more reasonable accuracy.

关键词： thermal model, thermal conductivity equation, soil initial, sensible flux, latent flux, two-layer model.