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Table of Content

    25 November 2011, Volume 50 Issue 6
    Fast Multiscale Petrov-Galerkin Algorithms for Weakly Singular Integral Equations
    CHENG Sirui;ZHAN Jiemin;CHEN Zhongying
    2011, 50(6):  1-6. 
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    The compressed multiscale Petrov-Galerkin algorithm for solving the second kind weakly singular integral equations is considered. We give the range of the truncation parameters and prove that the corresponding compression algorithm can achieve the optimal convergent order while preserving the stability, computational complexity and the uniformly boundedness of the condition number of the coefficient matrix. The numerical results verify the validity of the theoretical analysis.
    Research and Implementation of DCF Mechanism in MACLayer in Wireless Mesh Networks
    ZHOU Jieying;ZHANG Kang;CAI Dongzhe;HU Huiping
    2011, 50(6):  7-11. 
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    To cope with the deficiency that the IEEE 802.11 DCF in wireless mesh networks deploys all the nodes in the same way and cannot dynamically adjust their contention windows according to their real time status, the authors divides contention window into initial contention window, successfully sent window and conflict contention window. This scheme designs three different back off algorithms for the different windows so that dynamically adjusts the ability of nodes to accessing channel in different status and improves the fairness and throughput of network.

    Stability of the Finite Difference Scheme for a Higher Dimensional Nonlinear ReactionDiffusion Equation
    XU Chenmei;YU Jiliang;WANG Bo
    2011, 50(6):  12-15. 
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    The finite difference scheme with incremental unknowns for a higher dimensional nonlinear reactiondiffusion equation is presented by means of introducing incremental unknowns method and the stability of the scheme is discussed with nonlinear Galerkin method. Through stability analysis for the scheme, it was shown that stability of the finite difference scheme with the incremental unknowns is improved when compared with that of the corresponding classic difference scheme.
    Gracefulness of the Graphs Related to Wheel
    WANG Tao;LIU Haisheng;LI Deming
    2011, 50(6):  16-19. 
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    For any natural numbers n,p, which are not less than one, when m=2p+3 or 2p+4, the disconnected graphs Wm∪Kn,pand Wm,2m+1∪Kn,p are graceful; when i=1 or 2, the graph W2p+2+i∪G(i)p is graceful. If m is greater than or equal to three, and n is greater than or equal to s, where s is a natural number, Wm,2m+1∪St(n) is graceful; in particular, if m=2n+5, Wm,2m+1∪(C3∨Kn) is graceful.
    Explicit Formula of Kähler-Einstein Metric on CartanHartogs Domains
    DENG Yihua;XIAO Juan;YANG Zhifeng
    2011, 50(6):  20-22. 
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    The explicit formula of Kähler-Einstein metric and the equivalence of the Kähler-Einstein metric and the Bergman metric on Cartan-Hartogs domains are discussed. A unified explicit formula of Kähler-Einstein metrics on Cartan-Hartogs domains is given. Using this formula and a nature of continuous functions and the unified explicit formula of Bergman metrics, a unified proof of the equivalence of the Kähler-Einstein metric and the Bergman metric on Cartan-Hartogs domains is obtained.
    Global Weak Solution to a System of the Compressible Euler Equation with a Special Pressure and a Source
    SONG Guoqiang;;XIAO Jian;SHENG Liren
    2011, 50(6):  23-29. 
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    The maximum principle and the theory of compensated compactness are applied to establish an existence theorem for global weak solutions to the Cauchy problem of the non-strictly hyperbolic system—a system of the compressible Euler equation with a special pressure and a source. Homogeneous system of this system was first derived by Earnshaw S. in 1858 for isentropic flow and is also called the Euler equations of one-dimensional compressible fluid flow. The key is to obtain a priori-Lestimate for solutions of the Cauchy problem for the related parabolic system by using the maximum principle and give some source terms satisfying the conditions (C1)–(C3) of Theorem 1.
    Corner Transfer Matrix Renormalization Group Method and it's Application
    HE Chunshan
    2011, 50(6):  30-34. 
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    Renormalization group(RG) theory is a very important theory to research phase transition and critical phenomenon. With the development of the computing technology, numerical simulation methods based on the RG are used to compute the physical parameters. The corner transfer matrix renormalization group(CTMRG) method can get high precision results even if the physical system is in the critical status. CTMRG method is used to find the critical point of the twodimensional Ising model. The numerical critical coupling constant is consistent with the exact result with good precision(10-5).
    Synthesis and Optoelectrical Properties of AlY Co-doped ZnO Transparent Conducting Thin Films
    YANG Shenghong;JIANG Zhijie;ZHANG Yueli;TANG Jian;WANG Xusheng
    2011, 50(6):  35-38. 
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    The Al-Y co-doped ZnO tranparent conducting thin films were prepared on glass by Sol-Gel method. X-ray diffraction (XRD) showed they have hexagonal wurtzite structure with a C-axis preferred orientation. Its minimum resistivity is 1.63×102 Ω·cm, and the average transmittance in the visible region (400-800 nm) is beyond 85 %.
    The Heat Characteristics Research of a Watersoluble Ionic Liquid as Absorption Workers
    HUANGFU Lixia;WU Xiaohong;GUO Kaihua;DING Nan
    2011, 50(6):  39-42. 
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    Currently in the field of energy and refrigeration, the developing of highperformance absord energy transfer systems may find an breakthrough in the field of ciculate medium. As ionic liquid has the characteristics of “nondetectable” vapor pressure, wide liquid termperature range, stable, nonflammable, fluidness in room temperature, it may become absorbefacient better than metal salts (for example: LiBr). Combined with water,it may be the new generation of assimilated working pairs that have excellent competences. Watersoluble ionic liquid [BMIM]BF4 and [BMIM]2SO4 as the research objects were chosen to test and analyse their thermal stability, fluidness and vapor pressure of their aqueous solutions by experiments. Based on the thermal properties of these two kinds of ionic liquid, the foundation was built for further research of heat pump and ciculate refrigeration, which used ionic liquid as the absorption workers.
    A Method for PS to PP Reflection Time Mapping
    LI Shengjie;ZHANG Chuntao
    2011, 50(6):  43-47. 
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    PS to PP time mapping is one of key factors affecting seismic reservoir predictions in multicomponent seismic interpretations. Based on prior work, a new method is presented for the ratio of compressional velocity and shear velocity scanning and PS to PP reflection time mapping with using convertedwave prestack data. Model data results show that convertedwave velocity , the ratio of compressional velocity and shear velocity can be obtained directly from convertedwave seismic gathers, and P wave and PS wave reflection time can be automatically matched by means of the method presented. It works well with model data, suits for multicomponent seismic data processing in an area with horizontal formation.
    Digital Image Identification for Photographic Copying
    YIN Jing;FANG Yanmei
    2011, 50(6):  48-52. 
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    With advances in image display technology, recapturing goodquality images from the highfidelity artificial scenery, such as LCD screen or printed papers, becomes possible. This kind of highquality recaptured images may be used for illegal purpose, and they can also pass current identification systems without being recognized. It is studied how to detect recaptured photographs on LCD screen. By analyzing the noise in the photographs and detecting whether it exists double JPEG compression in the photography, the proposed features work well with a support vector machine classifier.
    Research on Key Resources Extension of Internet Architecture
    DIAO Yuping;LIAO Ming;DIAO Yongping
    2011, 50(6):  53-57. 
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    The two key issues of developing internet are internet autonomous problem and internet extensible problems. With the reality of internet, extensible architecture research proposes layer structure between autonomous network systems independent extensible autonomous DNS architecture and DNS mechanism. It also put forward the extensible addressing manner with bidirection dynamic source/destination NAT mechanism between autonomous network systems, and provides enough key network resources such as domain name, IP address for extensible usage. Therefore, Autonomous Extensible Internet(AEIP) could be realized in least cost and without transition period.
    Silver Nanoparticlesbased Antibacterial Hydrogels
    YANG Liqun;LIN Kaicheng;SHEN Rongchun;MA Lin;ZHANG Liming;LU Kang
    2011, 50(6):  58-61. 
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    The silver nanoparticlesbased hydrogels were investigated in order to increase the antibacterial property in this work. The silver nanoparticles were synthesized in aqueous silver nitrate solution by adding sodium borohydride as a reduction reagent and polyvinyl pyrrolidone as a dispersion aid. And then the silver nanoparticlesbased hydrogels were further prepared in the carbomer solution by adding the dispersion solutions of silver nanoparticles with different volumes and sodium hydroxide solution. The result of UVvis analysis indicated that the silver nanoparticles were successfully synthesized. The existence of silver nanoparticles in the hydrogels was confirmed by Xray scattering analysis, and the diameters of silver nanoparticles were calculated to be about 5 nm according to the Scherrer equation. The swelling ratio of the hydrogels was determined to be 900%. The hydrogels exhibited strong antibacterial properties to Escherichia coli and Staphylococcus aureus with the content of silver nanoparticles 10 μg/mL, which is lower than the safe content of silver nanoparticles 25 μg/mL. The hydrogels are thus anticipated to be used for the treatment of wounded skin and skin disease.
    Kinetics of Cellulase Based on the Model of Secondorder Enzymatic Deactivation
    ZHANG Yu;XU Jingliang;YU Qiang;LIU Yun;YUAN Zhenhong;QI Wei
    2011, 50(6):  62-66. 
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    Enzymatic hydrolysis of cellulose was extremely complex because of the unclear enzymatic hydrolysis, deactivation mechanisms and many factors that affect the heterogeneous system. Therefore, it is difficult to build a mechanistic model to study cellulose hydrolysis by cellulase. Under some assumed conditions such as the secondorder cellulase deactivation and quasi-steady state theory, a semi mechanistic and empirical model describing the relationship between product concentration and time, the initial enzyme concentration was deduced. The mathematic model was a simple mathematic function that contained only two parameters. The experimental result was in accordance with the deduced mathematic model, where the correlation coefficients (R2) were above 0.98. The relationship between initial enzyme concentration and initial hydrolysis rate calculated from the mathematic model showed good agreement with another type of Henri-Michaelis-Menten equation proposed by Bailey, where the R2 was 0.977 3. The maximum hydrolysis rate and half saturation constant was 2.742 4 g/(L·h) and 3.013 0 g/L, respectively. It was shown from the model that the rate constant of cellulase deactivation decreased when initial enzyme concentration increased under the certain substrate concentration, and the relationship between them was linear. The cellulase deactivation speed increased with the increase of enzyme concentration.

    Preparation and Photocatalytic Reduction of CO2 Using Novel AgBr/GO Nanocomposite Catalyst under Visible Light
    HUANG Yanling;HE Chun;MUDAR Abou Asi;SU Minhua;ZHU Linfei;XIA Dehua;SHU Dong
    2011, 50(6):  67-71. 
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    In this work, the AgBr/GO (graphite oxide) nanocomposite catalysts were prepared by the depositionprecipitation method in the presence of cetyltrimethylammonium bromide (CTAB), and their photocatalytic activities were evaluated by the reduction yield in the presence of CO2 and water under visible light (λ> 420 nm). The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that AgBr nanoparticles were well dispersed on the surface of GO supporter, which is beneficial to the transfer of photoexcited electrons from the conduction band of welldispersed AgBr to that of GO. The AgBr/GO nanocomposite had relatively high reduction yields under visiblelight irradiation for 5 h, with a methane yield of 106.11, methanol yield of 64.20, CO yield of 26.53, and ethanol yield of 10.96 μmol·g-1, respectively. It was obvious that the catalytic activity of AgBr/GO was higher than that of AgBr. In addition, it was found that AgBr/GO photocatalyst was stable in the repeated uses under visible light. The total yields of the photocatalytic products and stability on AgBr/GO after the 5 repeated uses almost remained the same. Therefore, the AgBr/GO nanocomposite is an effective and stable visiblelightdriven photocatalyst for CO2 photoreduction.

    The Metabolites of the Marine Fungus Penicillium sp. Associated with Soft Coral Sarcophyton tortuosum
    WANG Feng;LI Houjin;LAN Wenjian
    2011, 50(6):  72-77. 
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    Marine fungus Penicillium sp. was isolated from the soft coral Sarcophyton tortuosum collected in the South China Sea. While cultured in GPY medium, the fungal mycelia were reddish. Five compounds including (4E,6E) 2-N-hexadecanoyl-1,3-dihydroxyhexadeca-4,6-dien sphingosine(1), 1,7-dihydroxy-3-methoxy-6-methyl -anthraquinone macrosporin (2), 1,7,8- trihydroxy- 3- methoxy-6-methyl- anthraquinone (3), 1-hydroxy-3-methoxy-6-methyl-anthraquinone (4) and 4,8- dimethyl-1,5-dioxocane-2,6-dione (5)were obtained from the methanol extract of the fungal mycelia. Their structures were characterized by MS and NMR analyses. The result indicated that the compound (1) was a new compound, and the compounds 2,3,4,5 were first isolated from the marine fungus.
    Preparation of Cu-Ni/C Catalyst at Low Temperature for Synthesis of Dimethyl Carbonate (DMC)
    RUAN Jingtang;XIAO Min;WANG Shuanjin;MENG Yuezhong
    2011, 50(6):  78-81. 
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    Carbon supported copper-nickel alloy catalysts (Cu-Ni/C) were prepared by the low temperature hydrothermal reduction method. The Cu-Ni/C catalysts were characterized by FTIR, XRD,SEM and TEM analyses. The results indicated that the graphite oxide (GO) and metal precursors could be reduced at the same time. The TEM images showed that the alloy particles were well dispersed at the carrier surface with the size less than 50 nm for the catalyst synthesized at 90 ℃. The catalysis performances for direct syntheses of DMC form CO2and CH3OH were investigated and the highest CH3OH conversion of 4.2% and the DMC selectivity of 84.5% could be achieved.
    Synthesis and Antibacterial Effect Against Escherichia coli of TiO2:C Composite Film Deposited on Titanium
    MAI Lixiang;ZHANG Sheng;WANG Chunyang;XIE Yongjian;WANG Dawei;ZHANG Zhiguang
    2011, 50(6):  82-87. 
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    Undoped and Cdoped TiO2 films have been prepared by sol-gel process. The chemical components of the TiO2:C composite thin film were characterized using X-ray Photoelectron Spectroscopy(XPS). The antibacterial efficacy of the TiO2:C composite film was tested by film applicator coating method. Antibacterial mechanism of TiO2:C composite film was discussed by transmission electron microscope(TEM). It has been observed that C dopants retard the transformation from anatase to rutile phase. Namely, C doping effect is attributed to the anatase phase stabilization. More than 90% of bacterium were killed within 20 minutes which confirm fine antibacterial effect of the film.When studying the ultrastructure changes as the antibacterial material of TiO2:C thin film against Escherichia coli,the work indicated that the antibacterial particles of TiO2:C thin film may produce active oxides which contact the Escherichia coli cell and damage even penetrate the cells wall and plasmolemma to enter into the core to make cytoplasm agglomerate and thus cause the cells dead.

    Effects of Sub-Lethal Concentration of Nitenpyram on Soluble Protein, Glyceride,Free Amino Acid and Soluble Sugar of Brown Planthopper,Nilaparvata lugens (Stå1) (Homoptera: Delphacidae)
    ZHANG Jie;QIN Xiaowa;YUAN Fenghui;LIU Jie;HUANG Jie;ZHANG Runjie
    2011, 50(6):  88-93. 
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    We compared the changes of soluble sugar, glyceride, free amino acid and soluble protein contents in the 5th instar nymphs and adults of Nilaparvata lugens treated with sub-lethal doses of nitenpyram. The results indicated that the reserves of energy sources in nymphs and adults did have different variation trends. Soluble sugar contents in the 5th instar nymphs treated with LC10, LC30 stress in 12 h and 24 h and adults in 12 h stress were significantly higher than those 0f control; Glyceride contents in 5th instar nymphs and adults treated with LC10 stress were higher than those of control, but under 24 h stress, the glyceride content in the 5th instar nymphs was significantly lower than the control level; The variation trends of soluble protein contents in the 5th instar nymphs and adults were similar to that of free amino acid. The results suggested that under the control of sub-lethal doses of nitenpyram, the 5th instar nymphs and adults may have different coping mechanism and have important significance to understand the mechanism of sublethal doses of insecticide inducing resurgence of Nilaparvata lugens.

    The Molecular Phylogeny on Eight Species of Panulirus Genus from the Chinese Coast Based on COI Gene Sequence
    LIANG Huafang;;XU Xiaopeng;HUANG Zhijiang;WENG Shaoping;HE Jianguo
    2011, 50(6):  94-98. 
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    To study the phylogeny and select a DNA barcode for classification, the mitochondrial COI genes of eight lobster species, belong to the genus Panulirus, distributing along the coast of China were sequenced and analyzed. The genetic distance was calculated using MEGA4.0, and the phylogenetic trees were constructed with NeighborJoining (NJ) and Maximum Parsimony (MP) methods. The obtained COI gene fragments were 731 bp with GC contents ranging from 40.2% to 44.5%. The intraspecific genetic distances of these eight species, ranging from 0.00~0.057 with an average of 0.016, are small, and the interspecific genetic distances, ranging from 0.124 to 0.228 with an average of 0.185, are more than ten times higher than those of intraspecies. Eight species of Panulirus can be divided into two branches by NJ tree and MP tree: P. japonicus,P. longpies and P. penicillatus belong to a same branch; P. stimpsonic, P. polyphagus, P. versicolor, P. ornatus and P. homarus belong to the other. The results indicated that the COI gene could be a useful DNA barcode for taxonomic identification of lobsters.
    Effect of Polysaccharide Extract from Artificial Cordyceps sinensis on Immune Function of Mouse
    ZHONG Jianchun;ZHANG Yan;DING Zhentao;YE Kenan
    2011, 50(6):  99-102. 
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    To study the effect of polysaccharide extract from artificial Cordyceps sinensis on immune function of mouse, the methods including weight test of mice themselves and immune organs such as spleen and thymus gland, delayed hypersensitivity test,phagocytic function of monocyte macrophage test were adopted to evaluate the effect of polysaccharide extract on immune function of mouse。The results indicate polysaccharide extract can increase the weight of thymus gland and improve the delayed hypersensitivity induced by DNFB, it also can enhance phagocytic ability of monocyte macrophages but has no effect on the body weight of mouse. So Cordyceps sinensis may strengthen the immune function of mouse.
    HBV Genotypic Analysis and Population Analysis of HBV Genotype B/C Co-Infection in vivo
    YU Nan;CUI Jin;CHENG Xianghua;ZHOU Guobao
    2011, 50(6):  103-106. 
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    To investigate genotypes of HBV and the viral population in vivo in young women, we collected serum samples from 24 cases HBV carriers of 19~35 years old young women with both HBsAg and HBeAg positive. Twentyfour samples were tested 14 genotype B, 9 genotype C and one B/C genotypes co-infection. Nucleic acid extracts from 14 serum samples were used to amplify HBV large S protein genes through specific PCR. The amplification products were cloned and ten positive clones of each sample were selected for sequencing. The results confirmed that the 14 samples’ genotype were same. The case of B/C genotypes co-infection was a patient accepted adefovir antivirus therapy for 35 weeks. Four of the ten sequences were of genotype B with DA 2.8. The other six sequences were of genotype C with DA 0.6. There were three serotypes among the ten sequences through “α”determinant analysis. Population analysis suggested that the main genotypes of HBV infected young women in this region were B and C. HBV in vivo might distribute in a complex mode constructed with genotypes as well as quasispecies.
    Origin of the Blue Fog Zone and Black Crust of Myanmar Jadeite Jade Boulder
    YAN Weiwei;WANG Jianhua
    2011, 50(6):  107-113. 
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    The analysis on the geological background, sample observations, mineralogical and geochemical characteristics of Myanmar jadeite jade boulder indicates that the blue fog zone and black crust of the boulder are formed in dipositional diagenetic process under the conditions of certain temperature, pressure and fluid interaction. The hydrolysisdissolution of jadeite and precipitation of chlorite are the main causes of the formation of blue fog zone and black crust. The material sources of chlorite come from hydrolysisdissolution of jadeite,and Fe, Mg and other elements in fluid and sediments. The presence of organic matter may promote the migration and precipitation of Fe, Mg and other materials.
    Variability Recognition of the Nonuniformity of Annual Streamflow Distribution in the Dongjiang River
    TU Xinjun;CHEN Xiaohong;LI Ning;ZHANG Lijuan;
    2011, 50(6):  114-119. 
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    Based on the likelihood ratio method testing in the mean and the Schwarz Information Criterion testing in the variance, the variability of nonuniform coefficients of annual streamflow distribution in the gauging runoff series and reconstructed runoff series returning water regulation of three large reservoirs in the Dongjiang River is analyzed in this paper. Main conclusions are as follows:Compared to reconstructed series, annual mean values of the nonuniform coefficient of gauging series significantly decrease, being between 0.47-0.63, while annual variation coefficients remarkably increase, being between 0.34-0.48. The changepoint of the nonuniform coefficients obviously occurred in 1968. Both annual mean values and variation coefficients decrease distinctly after the change point, with values between 0.40-0.54 and between 0.25-0.32 respectively. The segmentation point of the nonuniform coefficient of reconstructed series also occurred in 1968 regardless of no tested change point. Annual mean values after the segmentation point show little change, but annual variation coefficients greatly decrease. The variability of the nonuniform coefficients in annual streamflow distribution is mainly resulted from water regulation of three reservoirs in the Donjiang River.Some other factors influence the annual variation range.

    The Change Characteristics of Sunshine Duration during the Past 48 Years in South China
    WU Hongyu;DU Yaodong;PAN Weijuan
    2011, 50(6):  120-124. 
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    Based on the annual sunshine duration data from 110 observational stations during 1961-2008 in South China,the climatic changes and the spatial temporal features of sunshine duration were studied by using statistical diagnostic methods,including linear regression analysis,MannKendall test,power spectrum function and the computation of trend coefficients. The results show that the annual mean sunshine duration shows a decreasing trend from South China to North China in the past 48 years.The highest center is located in Nanning of Guangxi(2552 h)and the lowest center in Jingxiu of Guangxi(1172h).The annual sunshine duration has declined at a mean rate of 4.09 h/a,which is higher than that of China. The changes of annual sunshine duration show significant 22 year and 11 year periods,with an abrupt change in the late 1970s. The trend of sunshine duration in South China has a remarkable regional difference. Decreasing trend of sunshine duration is obvious in most part of South China. There are three decreasing centers, located in Shenzhen of Guangdong(-12.86 h/a),Chengmai of Hainan (-12.85 h/a)and Hengxian of Guangxi(-11.85 h/a)respectively. The distribution of the annual mean sunshine duration is in accord with that of total cloudiness,but the secular trend variation of sunshine duration is different from that of total cloudiness.In most part of Guangdong, the total cloudinessincreases and the sunshine duration decreases obviously.

    Study on Flow Mixing Characteristics of the Largescale Biofilm Reactor
    SUN Guosheng;JIA Xiaoshan
    2011, 50(6):  125-129. 
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    Based on the hypothesis of series multistage continuous stirred reactor(CSTR), rodamine B tracing experiments were carried out in the biocontact oxidation tank of Dongshen raw water biopretreatment engineering, the largest engineering in the world, in order to get the fitting curve of the outlet concentration coefficient and mixed distance of CSTR stages using Mathlab, and then calculate series number of the reactor. Results show that the length of a singlestage CSTR is 13 m. The whole tank series number of CSTR with a length of 270 m is 21. It is incorrect that the biotank is considered simply as a plug flow reactor. About 71.8% water exchange occurs every 4.5 m at the aeration tube layer. The short flow does not exist in a singlestage CSTR.
    Study of the Influence of Wind Field on Air Quality over the Pearl River Delta
    ZHANG Renwen;;FAN Shaojia
    2011, 50(6):  130-134. 
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    Using daily data of wind speed and wind direction recorded at 14∶00 during 2006-2008 at 11 surface weather stations of the Pearl River Delta (PRD) and daily data of Regional Air Quality Index (RAQI) from 11 monitoring stations of the Hong Kong and Guangdong Pearl River Delta Air Quality Monitoring Network, the influence of wind field on air quality over the PRD were studied. Both in dry and wet seasons, the air quality of northern and eastern regions is better than that of southern and western regions of the PRD, and the air quality of central areas of the PRD is the worst. Regional transport has a great impact on the air quality of the PRD. When the regional mean wind speed (RMVS) is greater than 2.6 m/s, the air quality of the PRD is good. When RMVS is greater than 3.2 m/s, the air of PRD is very clean. When RMVS is less than 1.8 m/s, the air pollution of the PRD is serious. When RMVS is between 1.8 m/s and 2.6 m/s, the air quality of the PRD shows a complex change.