Table of Content

    25 July 2009, Volume 48 Issue 4
    Comparison Study on Two Methods to Calculate-Modal Response Sensitivities
    Zhongrong;XU Weihua;LIU Jike
    2009, 48(4):  1-4. 
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    The sensitivities of modal response with respect to structural physical parameter (i.e. elemental Young’s modulus) are derived. The sensitivities of modal displacement, velocity and acceleration responses with respect to the elemental Young’s modulus are derived from Newmark and State-space methods. A comparison study is carried out on calculation of the response sensitivities from these two methods. The results show that the computational time of state space method is less than that of Newmark method while the preciseness of two methods is almost the same. Thus, state-space method is more suitable for the calculation of dynamic responses in the forward analysis.
    Application of a New Model Coupling Denoising and Segmentation in Image Processing
    LUO Zhihong;;FENG Guocan;CHENG Qiusheng ;HU Yan 
    2009, 48(4):  5-10. 
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    Due to dissatisfactory results of segmenting the images corrupted by serious noise, a new model coupling denoising and segmentation is proposed. The image is denoised by a fused denoising model, then the denoised image is segmented by a novel segmentation model. Experimental results show that the proposed denoising model (by using AOS schemes)is better than some traditional denoising model .Moreover the excellent segmentation results of some highnoise images show that the proposed model coupling denoising and segmentation is effective and reliable and it has an advantage over CV model in segmentation.
    Well-posedness for a Free Boundary Problem Modeling Protocells
    BAI Meng;CUI Shangbin
    2009, 48(4):  11-14. 
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    A free boundary problem modeling the growth of protocells is studied, in which the evolution equation governing the motion of the free boundary Ω(t) is given by Vn=-vn-βv, where Vn denotes the normal velocity of Ω(t), v is the density of the building material, and β is a positive constant. The radially symmetric case of this problem was previously studied by Cui and Friedman in 1999. The general radially non-symmetric case is studied. With the abstract theory for parabolic differential equations in Banach spaces, the free boundary problem is locally well-posed in little Holder spaces is proved.
    SG Circle Patterns with a Negative Constant Cross-ratio and integrable systems
    GU Fangfang;LAN Shiyi
    2009, 48(4):  15-19. 
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    Power-low for Analysis of Impurity Distribution in Non-hyperadrupt Junction
    LI Chaorui;TANG Qiang;LIU Xiaowei
    2009, 48(4):  20-23. 
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    A Traffic Information Simulation System -Based on Mobile Communications Data
    ZHAO Lixuan;YU Zhi;HE Zhaocheng;LIN Ke
    2009, 48(4):  24-30. 
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    By developing a trajectory mapping model between vehicle and the corresponding mobile stations, data interaction and simultaneous simulation between the microscopic traffic simulation platform and the mobile communications platform are realized, and then a traffic information simulation system is constructed based on mobile communications data. By choosing the Mayong-Wangniudun Section on Guangzhou-Shenzhen Freeway as the simulation road section, the simulation data generating process of mobile communication is verified. Experiments show that the system can effectively simulate mobile stations traveling on the traffic network with vehicle characteristic and wireless communication features, also produce the location and handover data of the mobile stations, and provide reliable data for the research of traffic information extraction
    Wideband Adaptive Antenna Array with a Low Complexity
    XIE Ning;ZHOU Yuanping;WANG Hui;LIN Xiaohui
    2009, 48(4):  31-35. 
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    Based on the idea of frequency invariant, a wideband adaptive antenna array is proposed for wideband wireless communication system. With the algorithm,the array beam pattern remains basically the same within a wide frequency range of interest. At the same time,the level of sidelobe can be controlled through windows function. In comparison to the conventional wideband adaptive antenna array, the new algorithm offers a faster convergence rate with a lower computational complexity.
    Numerical Method and Application for Optical Maxwell-Bloch-Equations in Inhomogeneously Broadened Medium
    LI Cheng;ZHANG Huarong;YU Xiangyang
    2009, 48(4):  36-41. 
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    An accurate and effective numerical method is presented to solve the Maxwell-Bloch equations that are used to describe the optical pulse propagation and interaction with inhomogeneously broadened two-level medium. The convergence and stability of this numerical method are proved by comparing with the analytic solutions and area theorem derived under special condition.The simulations of arbitrary conditions is discussed by employing this method and analyze the pulse evolution for different detunings, relaxation times and inhomogeneously broadened linewidthes. The established numerical method provides a good way to have further study about the coherent interaction of short optical pulses with resonant mediums, and can be used to solve the corrections of Maxwell-Bloch equations.
    MISO Multivariate Generalized Polynomials Neural Network and its Weights-Direct-Determination
    XIAO Xiuchun;;ZHANG Yunong;JIANG Xiaohua
    2009, 48(4):  42-46. 
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    A new type of MISO(Multiple-Input, Single-Output) multivariate generalized polynomials neural network is constructed based on multivariate function approximation theory. According to least square theorem, a pseudoinversebased weights-direct-determination method is further presented to determine the neural-weights just in one step. Moreover, on the basis of this weights-direct-determination, a hidden-ayer evolution algorithm is proposed based on exponential-growth and binary-delete-search strategy. Theoretical analysis demonstrates that, since the weights-direct-determination method and the hidden-layer evolution algorithm could obtain the optimal weights directly without lengthy iterative BP-training, the constructed neural network could remedy the weakness of conventional BP neural networks, such as the existence of local-minima, choosing of learning-rate as well as the determination of the hidden-layer neurons. Computer simulation results substantiate the advantages of weights-directdetermination method and hidden-layer evolution algorithm for the constructed neural network, in the sense of training speed and high approximation precision.
    The Distributive Character and Pollution Assessment of Heavy Metals in Urban Soil of Guangzhou
    ZHUO Wenshan;TANG Jianfeng ;GUAN Dongsheng
    2009, 48(4):  47-51. 
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    The concentrations of and forms Ni,Cr,Pb,Zn and Cu in different functional zones are studied,the relationship between heavy metals and soil characteristics is analyzed.The results indicated that the surface soil was contaminated by heavy metals, especially in old industry and new residence zones.The concentration of Pb is high and should be paid more attention. Residual form were the major fraction of Ni,Cu and Cr, but the major form of Zn and Pb is Fe-Mn oxide form.
    Chemical Constituents in the Roots of Calophyllum membranaceum Gardn.
    CHEN Guangying;WU Xiaopeng;DAI Chunyan;ZHAO Jun;HAN Changri;SONG Xiaoping;ZHONG Qingxin
    2009, 48(4):  52-56. 
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    Eight compounds were isolated from the roots of Calophyllum membranaceum Gardn using silica gel column chromatography and sephadex LH-20chromatography, et al. Their chemical compounds were determined to be Friedelin (Ⅰ), Canophyllol (Ⅱ), Epi-friedelinol (Ⅲ), 3,4-dihydroxybenzoic acid(Ⅳ), Amentoflavone(Ⅴ), 7-dihydroxycoumarin(Ⅵ), Marmesinin(Ⅶ), Nodakenetin(Ⅷ) on the basis of comprehensive spectroscopic analysis and chemical method. Compounds Ⅵ,Ⅶ and Ⅷ were firstly isolated from this plant.
    Study on Dehydroabietylamine-substituted Salicylidene Schiff Bases byElectrospray Ionization Tandem Mass Spectrometry
    LIU Ming ;DENG Huimin;LIN Zhongxiang
    2009, 48(4):  57-60. 
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    Positive electrospray ionization tandem mass spectrometry was used to study seven novel synthesized dehydroabietylamine-substituted salicylidene schiff bases (DASSSB). The results showed that the MS2 fragmentation pathways of DASSSB were affected by the character and position of substitutes on salicylidene phenyl. The C=N cleaving to form fragmentation ion [M+H-283】+ was dominant for DASSSB compounds with electrondonating group on the C4 of the salicylidene phenyl; while fragmentation ion [M+H-254]+ forming by C-C cleavage of the β-position of C=N was dominant for DASSSB compounds with electron-withdrawing group on the C5 of the salicylidene phenyl. The characteristic MS2 fragmentation ions of DASSSB can be used for the qualitative and quantitative analyses.
    Functionary Mechanism between Sm(Ⅲ) HP Complex and DNA
    ZHAO Na;WANG Xingming;LI Hongbo;HU Yamin;FEI Dan;DING Lisheng
    2009, 48(4):  61-65. 
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    Using neutral red (NR) as a probe, functionary mechanism between Sm(Ⅲ)HP and DNA was studied by UVvis and fluorescence spectroscopy. The results indicated that the binding ratio of nSm(Ⅲ) ∶nHP is 1∶1,nSm(Ⅲ)HP ∶nDNA =1∶ 1, and the binding constant of Sm(Ⅲ)HP complex with Herring Sperm DNA was Kθ30℃=1.67×104 L/mol Thermodynamic parameters of enthalpy(Δr Hm), entropy(Δr Sm), and Gibbs free energy(Δr Gm) were calculated to be 4.86×104 J/mol, 195.61 J/(mol·K) and -1.06×104 J/mol, respectively. The results suggested that the process of interaction of Sm(Ⅲ)HP complex and Herring Sperm DNA was driven by entropy. The results of scatchard and probe methods suggested that the primary interaction mode between Sm(Ⅲ) HP and DNA was groove binding.
    Study on Novel Technology for Green Synthesis of Benzyl Acetate
    ZHOU Beilei;FANG Yanxiong;ZHAI Zhucheng;DENG Yunquan;HUANG Baohua;LAO Xiliao
    2009, 48(4):  66-69. 
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    The esterification of benzyl alcohol and acetic acid with N-methyl pyrrolidonium hydrogen sulfate ([Hnmp]HSO4) as a catalyst and the cyclohexane as a water-carrying agent was studied. The effects of different factors such as the amount of catalyst, reaction temperature, reaction time, molar ratio of acid to alcohol and the water-carrying agent were investigated in detail. The results showed that [Hnmp]HSO4 exhibited excellently catalytic activity. When the dosage of catalyst was 1% based on alcohol, the molar ratio of acetic acid to benzyl alcohols was 1.4∶1, the dosage of cyclohexane was 6 mL (the molar ratio of cyclohexane /benzyl alcohols was 0.56),the reaction temperature was 110℃,the reaction time was 1h,the yield of benzyl acetate was over 98%. The yield of benzyl acetate was 97.5% when the experiment was 10 times magnification. The catalyst could be reused for six times without significant yield declining. The corrosive experiment showed that the corrosive ratio of stainless steel in [Hnmp]HSO4 was 0.015 2 g/(m2·h)
    Theoretical Study on the Xyloketals Molecular Structure and its Inhibitory Calcium Channel Activity
    CHEN Haiyan;SHE Zhigang;LIN Yongcheng
    2009, 48(4):  70-72. 
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    The optimized geometries and electronic structures of xyloketals were calculated by the semi-empirical method PM3. The relationship of the xyloketals molecular structures and its inhibitory Calcium channel activity was analyzed based on the calculated results. It was found that there were correlations between the frontier molecular orbital HOMO, the molecular volume and the ClogP of the xyloketals.
    Preparation and Characteristics of OxysterolPhospholipid Vesicles
    TANG Wenxing;ZHENG Sijia;WANG Rongchang;YOU Xiuhua;LENG Tiandong;HU Haiyan;YAN Guangmei
    2009, 48(4):  73-77. 
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    To study characteristics of oxysterolphospholipid vesicles using 3,19-hydroxyl-cholestane-24-one (DHCO) and 3β,5α,6β-cholestane-triol (Triol) as oxysterols, respectively. Oxysterol-phospholipid vesicles were prepared by the ethanol-inpouring method. To measure fluidity and permeability of vesicles membrane, fluorescent intensities of lipophilic and hydrophilic fluorescence probes in the vesicles were determined. The inding percentage of DHCO and phospholipid to form vesicles was obtained by determining free and combined DHCO in DHCO-phospholipid vesicles solution. The effect of the ratio of DHCO to phospholipids and ultrasonic condition on the vesicle particle sizes and polydispersion index (PDI) was also investigated. DHCO-versicles and Triolvesicles had no significant difference in membrane fluidity from cholesterol (CHOL)-vesicles, but resulted in larger permeability than CHOL-vesicles. The binding percentage of DHCO and phospholipid was 82.58%. The DHCOvesicles and Triol-vesicles can be easily prepared by simple preparing process. DHCO-versicles with desired sizes and PDI could be obtained by optimizing the ratio of DHCO to phospholipid and the ultrasound condition. Depending on a huge database of numerous steroids,oxysterols could be viewed as potential "flowability buffers" in the development of vesicles.
    The Influence of Landscape Pattern Changes on the Restoration of Stream in the Upper, Middle and down Reaches of Dongjiang River Riparian
    ZHOU Ting;PENG Shaolin;REN Wentao
    2009, 48(4):  78-83. 
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    Based on Thematic Mapper remote sensing data of 1998 and 2006, a buffer zone along the stream of the Dongjiang River with width of 10 km is created by ArcGis. We identified 6 land use and land cover types using supervised classification techniques. In addition, upper, middle and down reaches were got with the catchments. A selected group of landscape metrics at the class and landscape level was used to quantify the changing pattern of land use and land cover in the study region using Fragstats. It is indicated that the conditions of water restoration are different in the different segments of the riparian buffer. The area of water patch decreased in the upper reaches, at the same time, the fragmentation also decreased. While in the middle and down reaches, both the area of water and the fragmentation increased. The area of vegetation patch increased in different degree. The proportion of farmland decreased in the whole riparian buffer, especially in the upper reaches, which may reduce the pollution of water. The increasing urbanization indicated by the increase of area and the aggregation distribution of builtup area, exhibit distinctly in the middle reaches. The increase of woodland and reduction of farmland will play a positive role in the restoration of water, while the urbanization may has a negative effect. It is concluded that the water in the upper reach changes little, the area of water in the middle reach increase greatly, while the restoration effect is weakened in the down reach for the population increase. It is suggested that the condition of each reach should be considered respectively during the restoration of water, and it is processed in the landscape level.
    Application and Primer Design of Mitochondrial DNA D-loop of Freshwater Fishes
    HUANG Zhijian;XU Xiaopeng;TANG Jingjing;ZHANG Ju;ZHENG Jinqing;LI Guifeng;HE Jianguo
    2009, 48(4):  84-88. 
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    Mitochondrial DNA (mtDNA) sequencing was widely used to identify, distinguish species and resolve phylogenetic relationships. In this studies, some published mitochondrial DNA D-loop sequences of major freshwater fishes were downloaded and made alignment. A pair of degenerate primers that targeted a portion of transfer RNA (tRNA)-pro and tRNA-phe were designed and used in a polymerse chain reaction (PCR) to amplify the control region. The primers can amplify mtDNA D-loop of 38 freshwater fishes in Zhujiang river area of Guangdong province. The size of amplification product is about 1kb. It is shown that the primers amplify a D-loop product of correct size only with the mtDNA which was extracted from the species with which the primers were designed to work. This result clearly demonstrates the efficiency and specificity of the primer pairs. The PCR fragments were all cloned and sequenced to confirm that they were indeed D-loop sequences.All mtDNA D-loop sequences were deposited in GenBank. The methods and the primers in this studies are very helpful for large-scale genetic analysis, molecular identification and phylogenetic analysis of freshwater fishes.
    Ecopath Model and Its Implication in Modelling the Effects of Spatial Closure in the Beibu Gulf Ecosystem
    CHEN Zuozhi;XU Shannan;LIN Zhaojin;HUANG Zirong;ZHONG Zhihui
    2009, 48(4):  89-94. 
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    Marine Protected Areas (MPAs) are increasingly being recognized as an alternative management tool for conserving marine resources and ecosystems. Based on the 1990s Ecopath with Ecosim model in the Beibu Gulf, we used Ecospace routine too forecast resources and fishery responses to different MPAs deployed (spatial closures system, closed season, common fishing zone and costal area with depth less than 30 m) in the Gulf of Beibu marine ecosystem over a 20year period. Simulations suggested that current trawl closures and closed season used in the Beibu Gulf fisheries, appear to be minimally benefits without the cooperation of fishers and costly administrative, the biomass of top predator groups, such as top demersal and pelagic fishes and elasmobranches would be decreased continuously during the simulation period. Both “notake zone”, coastal closures and common fishing zone closures can drastic reductions in fishing efforts and restoring declined fisheries resources, especially for high value fishes. This study supports predictions that MPAs can play a key role in the conservation of habitats and management of a fishery. It is suggested that for the purpose of fishery managements in the gulf, the costal areas with depth less than 30 m as “no take zone” may be an effective management tactic to conserve ecosystems and restore fisheries resources.
    Promoting Elimination Rate of Metabolites of Nitrofurans in TurbotScophthatmus maximus by Bromogeramine and Chinese Herbs: A Primary Research
    TAN Zhijun;GUO Mengmeng;XING Lihong;SUN Weihong;LI Zhaoxin;LENG Kailiang;ZHAI Yuxiu;
    2009, 48(4):  95-100. 
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    Research on promoting elimination rate of 3-amino-2-oxazolidinone(AOZ) and semicarbazide(SEM) in turbot Scophthatmus maximus which exposed to bromogeramine and Chinese herbs have been carried out. Generally, there are no obvious changes of the elimination rules of AOZ and SEM in turbot after exposed to bromogeramine and Chinese herbs for two months, and the content of AOZ and SEM still was much higher than detective limit even after having been eliminated for 185days, which have no obvious difference compared with the control. Bromogeramine couldn’t promote the eliminate rate but also showed toxicity to the turbot, and the turbot showed abnormal physiological phenomena. However, Chinese herbs could not only improve the immunity in turbot, but also promote the eliminate rate of AOZ and the depuration half-life of this chemical shortened for 3-5 days; On the opposite, Chinese herbs showed no positive effects on promoting eliminated rate of SEM, and even prolonged the depuration half-life. Therefore, bromogeramine should not be used for promoting the elimination of the metabolites of nitrofurans, and Chinese herbs showed potent roles for promoting elimination of these chemicals although more works were needed.
    Identification of Drainage Networks from DEMs -Considering Scale Transform
    YANG Bang;REN Liliang;WANG Guizuo;LIU Xiaofan;LI Guofang
    2009, 48(4):  101-106. 
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    The digital drainage network extracted by the low resolution DEM data is not reasonable enough to satisfy the requirement of hydrological modeling. Based on the drainage networks extracted by overland flow simulation algorithm developed by Mark and O‘Callaghan, the flow direction of high resolution grids was distributed to low resolution ones in five different watersheds,including the Zhaolanxin watershed, the Laohahe Watershed, the Dusitu watershed, the Qingliuhe watershed and the Mishui watershed. Then the digital networks extracted by high resolution DEM data were transformed into those on low resolution grids, by using the vector algorithm considering the maximal contributing area and identifying the flow direction of low resolution grids by the flow direction aggregation. Moreover, upscaled drainage networks were compared with drainage networks extracted from DEM data at different scales based on drainage networks’ density and widthfunction distribution. The results showed that this method was simple and effective either in flat area or in rough region. The digital drainage networks after transforming were up to the requirement of hydrological modeling.
    Decoloring Effect of Acid Brown Dye PR by Mold Pellet WY
    WANG Guohui
    2009, 48(4):  107-112. 
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    Mold pellet WY was studied on its decoloring characteristics of acid brown dye PR and effect of real printing and dyeing wastewater. WY had a wider decoloring temperature range.In the range of 25-50 ℃, the decoloring rate of PR was over 92%. The optimum decoloring temperature of pellet WY was 45 ℃,where the decoloring rate of PR reached 97.92% .The optimum pH of pellet WY was 5.0 and the optimum shaking speed was 90r/min and the corresponding decoloring rate of PR was 93.73% and 92.45% respectively. In the range of dye concentration of 100~300 mg/L, WY had high removal activity of dye PR and the removal rate reached 88.71%.Pellet WY needed some nutrition for the decoloration of PR WY had a wider range of carbon sources and nitrogen sources for the decoloration of PR.Waste milk was used as a nice nutrition for WY.The decoloring rate of milk-made pellet WY for PR. was 75.94% and 98.06% respectively when waste milk was added at 2% and 10% to the culture without carbon and nitrogen sources. Pellet WY had better decoloring activity for real printing and dyeing wastewater, with decoloring rate 86.24%. Methanol had good desorption effect with desorption rate 97.17%.After desorption, the pellet still had good decoloring effect and the decoloring rate was 93.78%.Pellet WY could be reused.
    Influencing Factors of Residual Chlorine Decay Curve and Its Mathematical Model
    HUANG Guoxian;QIAN Yujia;GE Jieju;NIE Yuhua;LIU Wei;LIANG Yongmei
    2009, 48(4):  113-117. 
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    Residual available chlorine curve and its modeling are essential for researches on disinfection of recycling wastewater and dosing control in practice. Batch tests were conducted to investigate the decay of chlorine in the disinfection of secondary effluent from wastewater treatment plants. The influence of some major parameters such as TOC, dosage and pH on the decay curve of free chlorine and chloramines was evaluated. The first order, second order, parallel first order and polynomial order were used to simulate the decay curves for comparison. It was found that decay curves of chlorine and chloramines in recycled wastewater followed the parallel first order and polynomial models. High TOC, low pH and/or high dosage of chlorine increased the decay rate of chlorine.
    LiDAR Detection Model of Tidal Wetland -Microrelief Based on Ground Constraint Conditions
    QIAO Jigang;LI Xia;LIU Xiaoping
    2009, 48(4):  118-124. 
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    High resolution digital terrain model derived up from LiDAR point clouds can provide more details of microrelief information for tidal wetland environment researches. Tidal wetland microrelief is divided into four components based on LiDAR classification models: underwater points, shoal, bank, and wet or dry ditches.Using ground features as constraint boundary, the foot points of ditches and bank are picked up from a land point cloud with multiiteration classification tools.The reflect intension and point density of LiDAR point cloud are calculated. Using the intension and density threshold values in point cloud classification, shoal, underwater points and wet ditches can be identified.Taking Citrus County, west coast of Florida as a case study, a microrelief DEM is built. A fitting analysis and a flood submergence process are carried out to check up the DEM precision. Comparing with the result of image eyes judgment,the classification model proposed in this paper can generate microrelief DEM with more details than general slope threshold models do.
    Bioavailability Assessment of Heavy Metals in the Vicinity of Dabaoshan Mine
    HUANG Suihong;TIAN Tian;ZOU Xiaojin;ZHOU Xiaoyong;PALANINAICKER Senthilkumar;QIU Rongliang;
    2009, 48(4):  125-129. 
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    In this study, the predictive ability of six extractants (HCl, DTPA, CaCl2, NH4 NO3, MgCl2 and deionized water) was investigated with respect to bioavailability of Pb, Zn, Cu and Cd in three types of vegetable planted soils, which were collected from Shangba Village near Dabaoshan mine. The results showed that Pb extracted by HCl and DTPA and the Zn extracted by CaCl2, NH4NO3 and MgCl2 had good correlation with metals concentrations in the three vegatables. Among six extractants, CaCl2 extractable Cd showed the best correlation with bioavailable Cd.Extracted Cu by all six extractants had no significant correlation with Cu concentrations in vegetables. HCl-and DTPA-extractable Fe and Mn concentrations were very high in soils,which indicated that most of Pb, Zn, Cu, and Cd were tightly bound with these fractions and this might be responsible for low extraction rate. Comparing with Pb, Cu and Cd,Zn was least affected by Fe and Mn oxides. Moreover,the heavy metal concentrations in roots could be more reasonable indices to investigate the transfer from soil than those in shoots.
    The Number of Critical Periods for a Planar Polynomial Systems
    CHEN Yanyan ;
    2009, 48(4):  130-132. 
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    To study the number of critical periods for a planar polynomial system, the formula of the period function is obtained.Using the result, the upper bound for the number of one order critical periods and two order critical periods are obtained.
    The Secondary Metabolites of the Mangrove Endophytic Fungus(ZZF13) from the South China Sea
    XIA Xuekui ;LI Qing;SHAO Changlun;LIU Changheng;SHE Zhigang;LIN Yongcheng
    2009, 48(4):  133-136. 
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    The secondary metabolites of the fungus ZZF13 were first isolated from the leaves of the mangrove sample Kandelia candel in Zhanjiang. Five compounds were isolated from the culture of this strain. They were determined to be skyrin (1), lichenxanthone (2), griseoxanthone C (3), 1,3,6-trihydroxy-8-methyl-9H-xanthen-9-one (4) and 5,7-dihydroxy-2-methyl- 4Hchromen-4-one (5) by comprehensive spectroscopic analysis. Compounds 1 and 5 showed inhibitory activities against Bacillus subtilis ATCC 6633 with MIC values of 100和100 μg/mL, respectively.
    A Taxonomic Study on Pseudebulea Butler from China (Lepidoptera: Crambidae: Pyraustinae)
    ZHANG Dandan;LI Zhiqiang
    2009, 48(4):  137-140. 
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    This paper deals with five species of the genus Pseudebulea Butler from China. Among them, Pseudebulea polychaeta sp. nov. is described as new to science. Photograph and genital structures of the new species are provided. A key to all the known species is given.
    Optimal Control of Roundabout
    WANG Xinhua
    2009, 48(4):  141-142. 
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    For the roundabout of n (n≥ 4) intersections, by the use of restraint of the interweave section volume, linear programming model based in capacity is established. For 2 lanes uncontrolled entrances and exits, optimal value of capacity is obtained; for 3 lanes entrances and exits, under the condition of signalized leftturn, computing method of optimal proportion of the green signal and optimal timing in every intersection is provided.