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Imaging theory of nonlinear second harmonic and third harmonic generations in confocal microscopy

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Science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 8-16页

作者： TANG Zhilie1. XING Da2.& liu Songhao{1.. Department of Physics, south china Normal university, guangzhou 51.631. china 2. School for information and Optoelectronic Science and Engineering, south china Normal university, guangzhou 51.631. china Correspondence should be addressed to Tang Zhilie (email: tangzhl@***) Received April 2., 2.03 1. Department of Physics South China Normal University 510631 Guangzhou China 2. School for information and Optoelectronic Science and Engineering South China Normal University 510631 Guangzhou China

The imaging theory of nonlinear second harmonic generation (SHG) and third harmonic generation (THG) in confocal microscopy is presented in this paper. The nonlinear effect of SHG and THG on the imaging properties of confocal microscopy has been analyzed in detail by the imaging theory. It is proved that the imaging process of SHG and THG in confocal microscopy, which is different from conventional coherent imaging or incoherent imaging, can be divided into two different processes of coherent imaging. The three-dimensional point spread functions (3D-PSF) of SHG and THG confocal microscopy are derived based on the nonlinear principles of SHG and THG. The imaging properties of SHG and THG confocal microscopy are discussed in detail according to its 3D-PSF. It is shown that the resolution of SHG and THG confocal microscopy is higher than that of single- and two-photon confocal microscopy.

关键词： second harmonic generation, third harmonic generation, confocal microscopy, three-dimensional point spread function.

Transitional function of DG to CA3 in the hippocampus

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Progress in Natural Science:Materials International 2007年第12期17卷 1436-1444页

作者： Yan Chuankui1.and liu Shenquan{1.. Department of Mathematics, Hangzhou Normal university, Hangzhou 31.036, china 2. Department of Applied Mathematics, School of Mathematical Sciences, south china university of Technology, guangzhou 51.640, china) Department of Mathematics Hangzhou Normal University Hangzhou 310036 China Department of Applied Mathematics School of Mathematical Sciences South China University of Technology Guangzhou 510640 China

Using single cell channel model, the transmission features of CA3-DG network in the hippocampus are investigated. The influence of the stimulation on discharge pattern of pyramidal neurons is analyzed, which shows that it starts with period spiking discharges, followed by period-doubling bifurcation to chaos, and period 3 discharge evolving into chaos, and ultimately a period of bursting discharges. By the synaptic model, the CA3-DG network model is constructed, which analyzes the summation of postsynaptic currents in the network, the influence of postsynaptic current on discharge rhythm as well as the mechanism of bursting discharges. The strong capacity of spatiotemporal encoding in the network indicates the features of CA3 network during the information transmission process in the hippocampus. The modeling result with time delay of the synaptic transmission is in accordance with the experimental phenomena of action potential in the hippocampus.

关键词： hippocampus CA3-DG period-doubling bifurcation chaos.

Highly efficient transformation of intact yeast-like conidium cells of Tremella fuciformis by electroporation

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Science china(Life Sciences) 2008年第10期51卷 932-940页

作者： GUO LiQiong1.2. liu Yong1. ZHAO ShuXian1. liu ErXian1.& LIN JunFang1.2.1 college of Food Sciences, south china agricultural university, guangzhou 51.640, {12. 2.Institute of Biomass Research, south china agricultural university, guangzhou 51.640, {12. 1. college of Food Sciences South China Agricultural University Guangzhou 510640 China 2. Institute of Biomass Research South China Agricultural University Guangzhou 510640 China

Tremella fuciformis is one of higher basidiomycetes. Its basidiospore can reproduce yeast-like conidia, also called the blastospore by budding. The yeast-like conidia of T. fuciformis is monokaryotic and easy to culture by submerged fermentation similar to yeast. So it is a good recipient cell for exogenous gene expression. In this study, two expression vectors pGlg-gfp containing gpd-Gl promoter and gfp gene and pGlg-hph containing gpd-Gl promoter and hph gene were constructed. The lowest sensitive concentration of hygromycin for the blastospore was determined on three types of media. Our ex- periments showed that the lowest sensitive concentration of hygromycin for the blastospore was 5 μg/mL on MA medium. The intact blastospores were transformed with the expression vector pGlg-hph by electroporation. The putative transformants were obtained by the MA selective medium. Experi- mental results showed that the most effective parameters for the electroporation of intact blastospores were obtained by using STM buffer, 1.0×1.8 cells/mL of blastospores, 2.0 μL in transformation volume, 6 μg plasmid, 2.0 kV/cm of electric pulse voltage, stillness culturing on MB liquid medium for 48 h after electroporation. In these transformation conditions, the efficiency reached 2.7 colonies/μg DNA. Co-transformation of plasmid pGlg-gfp and pGlg-hph with ratio of 1.1.was performed by electroporation with the optimal parameters. The putative co-transformants were obtained by the MA selective medium. Eight randomly selected colonies from the vast putative co-transformants were analyzed by PCR de- tection and southern blotting. The experiments showed that the gfp was integrated into the genomes of three transformants. The co-transformation efficiency was 37.5%. Green fluorescence was observed under laser scanning confocal microscope in these gfp positive transformants. This indicates that the exogenous gfp can be expressed effectively in the yeast-like conidia of T. fuciformis.

关键词： Tremella fuciformis electroporation yeast-like conidia intact cells gene expression hph gene gfp gene

Electrochemical Characterization of Surface-modified LiMn_2._4 Cathode Materials for Li-ion Batteries

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Journal of Wuhan university of Technology(Materials Science) 2006年第4期21卷 56-59页

作者：禹筱元 college of Science South China Agricultural University Guangzhou 510642ChinaSchool of Physics & Engineering Sun Yat-sen University Guangzhou 510275China

To improve the performance, the surface of 1.Mn2.4 was coated with very fine MgO , Al2.3 and ZnO by solgel method, respectively. The structure and morphology of the coated materials were investigated by X-ray diffraction （ XRD ）, X-ray photoelectron spectroscopy （ XPS ） and scanning electron microscopy （SEM）. The charge and discharge performance of uncoated and surfnce modified 1.Mn2.4 spinel at 2.℃ and 55 ℃ were tested, using a voltage window of 3.0-4.35 V and a current deasity of 0. 1.C rate. There is a slight decrease in the initial discharge capacity relative to that of uncoated UMn2.O4, bat the cycle ability of 1.0}2.n2.4 coated by metal-oxide has remarkably been improved. The EIS measuremeuts of uncoated and Al2.3 -coated 1.Mn2.4 were carried out by a model 2.3 A potentiostatl galvanistat controUed by a computer using M2.0 software, and using a freqnency response analyzer （ Zsimpwin ） combined with a potentiostate （ PAR 2.3）. Coaseqnently, the reason for the improved cycle properties is that the surface modification reduces the dissolution of Mn , which results from the suppression of the electrolyte decomposition, and suppresses the formation of passivation film that acts as an electronic insulating layer. In conclusion, the use of surface modification is an effective way to improve the electrochemical performance of 1.Mn2.4 cathode material for lithium batteries.

关键词： lithium-ion batteries surface modification metal-oxide coating: 1.Mn2.4 cathode

Optical pulse compression using a nonlinear optical loop mirror constructed from dispersion decreasing fiber

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Science china(Technological Sciences) 2004年第1期47卷 33-50页

作者： CAO Wenhua & liu SonghaoSchool of {1., Wuyi {2., Jiangmen 52.02., china School for {1. and Optoelectronic Science and Engineering, south china Normal {2., guangzhou 51.631. china 1. School of information Wuyi University 529020 Jiangmen China 2. School for information and Optoelectronic Science and Engineering South China Normal University 510631 Guangzhou China

A novel scheme to compress optical pulses is proposed and demonstrated numerically, which is based on a nonlinear optical loop mirror constructed from dispersion decreasing fiber (DDF). We show that, in contrast to the conventional soliton-effect pulse compression in which compressed pulses are always accompanied by pedestals and frequency chirps owning to nonlinear effects, the proposed scheme can completely suppress pulse pedestals and frequency chirps. Unlike the adiabatic compression technique in which DDF length must increase exponentially with input pulsewidth, the proposed scheme does not require adiabatic condition and therefore can be used to compress long pulses by using reasonable fiber lengths. For input pulses with peak powers higher than a threshold value, the compressed pulses can propagate like fundamental solitons. Furthermore, the scheme is fairly insensitive to small variations in the loop length and is more robust to higher-order nonlinear effects and initial frequency chirps than the adiabatic compression technique.

关键词： dispersion decreasing fiber (DDF), optical pulse compression, optical solitons.

Soil Components Affecting Phosphate Sorption Parameters of Acid Paddy Soils in Guangdong Province

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Pedosphere 2000年第4期10卷 317-321页

作者： LI HUAXING, ZHANG XINMING and liu YUANJIN ({1. of Natural Resources and Environment,{2., guangzhou 51.642.china) 华南农业大学广东广州 510642

Soil components affecting phosphate sorption parameters were studied using acid paddy soils derived from basalt, granite, sand-shale and the Pearl River Delta sediments, respectively, in Guangdong Province. For each soil, seven 2.50 g subsamples were equilibrated with 50 mL 0.02.mol L-1.(pH=7.0) of KCI containing 0, 5, 1., 1., 2., 50 and 1.0 mg P kg-1. respectively, in order to derive P sorption parameters (P sorption maximum, P sorption intensity factor and maximum buffer capacity) by Langmuir isotherm equation. It was shown that the main soil components influencing phosphate sorption maximum (Xm) included soil clay, PH, amorphous iron oxide (Feo) and amorphous aluminum oxide (Alo), with their effects in the order of Alo > Feo > pH > clay. Among these components, pH had a negative effect, and the others had a positive effect. Organic matter (OM) was the only soil component influencing P sorption intensity factor (K). The main components influencing maximum phosphate buffer capacity (MBC) consisted of soil clay, OM,pH, Feo and Alo, with their effects in the order of Alo > OM > pH > Feo > clay. Path analysis indicated that among the components with positive effects on maximum phosphate buffer capacity (MBC), the effect was in the order of Alo > Feo > Clay, while among the components with negative effects, OM > pH. OM played an important role in mobilizing phosphate in acid paddy soils mainly through decreasing the sorption immensity of phosphate by soil particles.

关键词： Guangdong Province phosphate sorption parameters soil components

Molecular characterization and expression analysis of caveolin-1.in pig tissues

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Science china(Life Sciences) 2008年第7期51卷 655-661页

作者： WANG Chong1.MEI YingJie 1.LI Li 1.MO DeLin 2.LI JiaQi 1.ZHANG Hao 1.TIAN XingGuo 1.&CHEN YaoSheng2.1{1. of Animal Science,south china agricultural university,{12. 51.642.china 2.chool of Life Science,Sun Yat-Sen university,{12. 51.006,china 1. college of Animal Science South China Agricultural University Guangzhou 510642 China 2. School of Life Science Sun Yat-Sen University Guangzhou 510006 China

Members of the caveolin family played important roles during fundamental cellular processes,such as regulation of cell morphology,migration,and gene expression in muscle *** this study,caveolin-1.(Cav-1.,one of the caveolins,was identified from longissimus dorsi muscle of Large Yorkshire pig and Chinese indigenous Lantang pig based on the results of mRNA differential display *** deduced amino acids sequence of the porcine Cav-1.contained a caveolin domain,and was very conservative among different *** Cav-1.mRNA was widely expressed in the eight tissues in this study,including heart,liver,kidney,encephalon,spleen,lung,longissimus dorsi muscle,and back fat, and the highest expression quantity was found in back fat of the two pig *** expression quantity of porcine Cav-1.in back fat and longissimus dorsi muscle of Lantang pig was significantly higher than that of Large Yorkshire(P1.and P1.might be a candidate gene for carcass traits,and might provide valuable information for understanding the mechanism of caveolae signaling in fat deposition by using the animal model of pig.

关键词： caveolin family clone expression analysis real-time quantify PCR

Study on NDVI-T_s space by combining LAI and evapotranspiration

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Science china Earth Sciences 2006年第7期49卷 747-754页

作者： HAN Lijuan1.2.3, WANG Pengxin4, YANG Hua1.2.3, {2. Shaomin1.2.3 & WANG Jindi1.2.3 1. Research Center for Remote Sensing and GIS, School of Geography, Beijing Normal {1., Beijing 1.0875, china 2. State Key Laboratory of Remote Sensing Science, Beijing 1.0875, china 3. Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities, Beijing 1.0875, china 4. Department of information Management, college of information and Electronic Engineering, china agricultural {1., Beijing 1.0083, china 1. Research Center for Remote Sensing and GIS School of Geography Beijing Normal University Beijing 100875 China 2. State Key Laboratory of Remote Sensing Science Beijing 100875 China 3. Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing 100875 China 4. Department of information Management College of Information and Electronic Engineering China Agricultural University Beijing 100083 China

This paper focuses on interpreting the different spatial relationships between NDVI and Ts, a triangular or a trapezoid, and on analyzing transformation conditions, the physical and ecological meanings of the vegetation index-surface temperature space as well. Further, we use the Tempera-ture-Vegetation Dryness Index (TVDI) to explain the existent meaning of a triangular space after NDVI reaches its saturated state by employing the relationships between NDVI, LAI and evapotranspiration. The specific relations between NDVI and Ts are useful for describing, validating and updating land surface models.

关键词： NDVI, land surface temperature, evapotranspiration, leave area index.

Development of simple sequence repeats (SSR) markers of ramie and comparison of SSR and inter-SSR marker systems

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Progress in Natural Science:Materials International 2005年第02期15卷 42-47页

作者： ZHOU Jianlin1., JIE Yucheng2., JIANG Yanbo2. ZHONG Yingli1. {2. Yunhai1.and ZHANG Jian1.*(1. Department of Biochemistry and Molecular Biology, {1. of Life Science, Hunan Normal university, Changsha 41.081. china 2. Institute of Bast Fiber Crops, Chinese Academy of agricultural Science, Changsha 41.006, china) Department of Biochemistry and Molecular Biology College of Life Science Hunan Normal University Changsha 410081 China. Institute of Bast Fiber Crops Chinese Academy of Agricultural Science Changsha 410006 China

Ramie (Boehmeria nivea L.) is an important bast fiber crop. To study genetic background of this species, we isolated and characterized microsatellite markers of ramie. A genomic library containing inserts of rapid amplification of polymorphic DNA (RAPD) fragments was constructed, and screened by PCR amplification using anchored simple sequence repeats as primers. A total of 2. clones were identified as positives, and 1. microsatellite loci were found after sequencing. The polymorphism of these 1. microsatellite loci was examined and the utility of simple sequence repeats (SSR) and inter-SSR (ISSR) marker systems for genetic characterization compared using 1. selected ramie cultivars. Both approaches successfully discriminated the 1. cultivars which differed in the amount of polymorphism detected. The level of polymorphism detected by SSR was 95.0%, higher than that by ISSR (72.3%), but the average polymorphism information content (PIC) of ISSR (0.651. was higher than that of SSR (0.441.. The higher PIC value of ISSR suggests that ISSR is more efficient for fingerprinting ramie cultivars than SSR markers. However, because the SSR loci are codominant, they are more suitable for determining the homozygosity levels of ramie, constructing linkage map, quantitative trait loci study of complex traits and marker-assisted selection.

关键词： ramie (Boehmeria nivea L.Gaud) simple sequence repeats inter-simple sequence repeats