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Table of Content

      
    16 September 2008
    Volume 43 Issue 9
    Articles
    Purification and antifungal activity examination of water-soluble starfish glycosides from Asterias rollestoni
    FAN Ting-jun,ZHANG Zheng,YUAN Wen-peng ,CONG Ri-shan,WANG Wei-wei,JING Zhao
    J4. 2008, 43(9):  1-05 .  doi:
    Abstract ( 1074 )   PDF (560KB) ( 890 )   Save
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    To exploit highly bioactive natural antifungal medicaments from starfish, water-soluble starfish glycosides from Asterias rollestoni were isolated and purified by macroporous resin column and silica gel column chromatography, and their antifungal bioactivities were also examined. Among the macroporous resin fractions of 30%, 50%, 70%, 80% and 95% ethanol, 70% ethanol eluted fractions showed the highest antifungal activity towards Schizosaccharomyces pombe and Candida albicans. After being checked by thin layer chromatography, purified SF-1, SF-2, SF-3 and SF-4 fractions were obtained from 70% ethanol eluted fractions with a silica gel column. Among the purified fractions, SF-3 and SF-4 showed much higher antifungal activities, while SF-1 did not show any antifungal activities and SF-2 had only very lower antifungal activities. SF-3 exhibited a single peak after loaded onto a high pressure liquid chromatography (HPLC) column, which indicated that SF-3 was pure enough to be used as a candidate of antifungal medicament development. This research will lay a solid foundation for the development and application of natural and highly bioactive antifungal medicaments.
    Optimization of selective conditions for the selection of uracil auxotrophs of thermophilic archaea Sulfolobus tokodaii
    HUANG Qi-hong,SHEN Yu-long,NI Jin-feng*
    J4. 2008, 43(9):  6-10 .  doi:
    Abstract ( 877 )   PDF (730KB) ( 756 )   Save
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    Thermophilic archaea Sulfolobus tokodaii was recognized as a species of the genus Sulfolobus, which belongs to Crenarchaea of Archaea. Orotate phosphoribosyl transferase and orotidine monophosphate decarboxylase, expressed by a uracil-related gene in the wild type of Sulfolobus tokodaii, could transform 5-fluoroorotic acid (5-FOA) to the toxic substance 5-fluorouridine monophosphate. Therefore, the wild-type strain could not grow normally. The selective condition was optimized based on this theory, such as the effective concentration of 5-FOA and the time of UV irradiation, and several uracil auxotrophs mutants of S.tokodaii were primarily obtained by spontaneous change or UV mutagenesis.
    Agrobactrium tumefaciens mediated DREB1A gene transfer to Lolium multiflorum and optimization of its genetic transformation
    LI Zi-dong ,ZHAO Cui-zhu,ZHOU Ling-jun,LIU Yan-ling,XIANG Feng-ning *,XIA Guang-min
    J4. 2008, 43(9):  11-17 .  doi:
    Abstract ( 867 )   PDF (615KB) ( 623 )   Save
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    The embryo-derived calli from Lolium multiflorum Lam were transformed with Agrobactrium tumefaciens AGL1 harboring intron-DREB1A expression vector pBI121 containing ubiqutin promoter, nptⅡ marker gene and GUS gene. After infection and co-culture with AGL1, the embyogenic calli were selected with 50mg/L paromomycine and plants regenerated from the resistant calli. All plants were selected further with 25mg/L kanamycin, some of which remained green. The genome DNA of the resistant plants was checked with specific primers and probes from the DREB1A gene. The results of PCR and PCR-Southern blot assay indicated that the DREB1A gene was transferred into Lolium multiflorum Lam with a transformation frequency of 2.14%. It was found that the transformation efficiency can be efficiently improved using the following transformation conditions: Agrobacterium cell density of OD600≈2.0, incubation for 1 hour, coculture at 21℃ for 2 days and application of As in coculture.

    Study of the effects on the formation of the liquid crystal system loading Chlorpyrifos

    KONG Xiang-jie,LI Li-fang * ,WANG Li,XU Ming-kao
    J4. 2008, 43(9):  18-21 .  doi:
    Abstract ( 855 )   PDF (384KB) ( 895 )   Save
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    Effects of organic solvents, temperature, n-alcohols and inorganic salt on the formation of the liquid crystal phase were investigated to discuss the formation law of the liquid crystal system loading chlorphyrifos. The results showed that the substituent in the phenyl ring was advantageous to the formation and maintenance of the liquid crystal phase. A high temperature could cause the system water content to rise when the liquid crystalline phase formed and vanished. With an increase of the chain length of n-alcohols, the minimum water content for the liquid crystal formation slowly increased. When the liquid crystal phase vanished, the maximum water content first rose and then dropped. It was found that, by adding inorganic salt, the maximum water content needed for the disappearance of the liquid crystal phase decreased with hydrated radius of positive ions decreasing, which showed that the liquid crystal structure was unstable.
    Preparation and characterization of Y doped Ti/Sb2O5-SnO2
    electro-catalytic electrodes
    LI Shan-ping,FU Jing,HU Zhen
    J4. 2008, 43(9):  22-26 .  doi:
    Abstract ( 788 )   PDF (724KB) ( 915 )   Save
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    Yttrium was selected as a promoter for the Ti/Sb2O5-SnO2 electrode to enhance its electro-catalytic characteristics and Y doped Ti/Sb2O5-SnO2 electrodes were prepared by the immersion method. Degeneracy of the prepared electrodes was investigated using reactive brilliant red X-3B as a model pollutant. The parameters of preparing the electrode, including temperature and Y doping content, were studied in detail. The optimal pyrolytic temperature was 550℃, and Y doping content was 0.8%. The micrograph of the electrode surface, the element composition of different layers and the structure of the electrode were analyzed by SEM, EDS and XRD. Compared with the Ti/Sb2O5-SnO2 electrode, the average size of SnO2 grains on the electrode surface of the Y doped Ti/Sb2O5-SnO2 electrode was smaller, which implies a potential improvement in catalytic performance. Sb and Y were found to be enriched in the coated layer on the electrode surface when Y was introduced. The surface of the Y doped Ti/Sb2O5-SnO2 electrode was mainly composed of tetragonal rutile structure SnO2 crystal. The potential sweep results indicate that the Y doped Ti/Sb2O5-SnO2 electrode has high oxygen evolution potential which is in favor of electrochemical oxidation for organic pollutants.
    Study on the prediction of urban water requirement of Shandong Province
    REN Li-jun,YUAN Cun-chao,CUI Zhao-jie
    J4. 2008, 43(9):  27-30 .  doi:
    Abstract ( 773 )   PDF (259KB) ( 1016 )   Save
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    The level of urbanization of Shandong Province has been growing at the speed of 1.0%~1.5% per year since the year 1995 and it reached 46.1% in the year 2006. However the urbanization process at such a rapid speed made the water crisis more serious. First, the level of urbanization in the near future was predicted by use of the United Nations method and liner analysis method, so the urban population in the province was determined. Then according to the different kinds of water use, the water requirement for city-living, industry and ecology was forecasted using the scenario analysis and model prediction. Finally, some suggestions were given for sustainable water use and protection in Shandong Province.
    Adsorption of phenol on cationic polymer/bentonite and the mechanism research
    LI Jing,YUE Qin-yan*,LI Qian,GAO Bao-yu,YUAN Ai-juan
    J4. 2008, 43(9):  31-35 .  doi:
    Abstract ( 1488 )   PDF (751KB) ( 735 )   Save
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    Two cationic polymer-epicholorohydrin-dimethylamine(EPI-DMA) and poly dimethyldiallylammonium (PDMDAAC) as intercalary reagents were respectively used to prepare a series of cationic polymer/bentonites. The adsorption of phenol on cationic polymer/bentonite and major effect factors were studied. The results showed that the adsorption ability of bentonite for phenol was improved greatly after modification. The pH of the solution, temperature, time of reaction and salt concentration have influences on the adsorption. The adsorption equilibrium time of PDMDAAC/bentonite and EPI-DMA/bentonite is respectively 20min and 60min. The adsorption ability decreases at higher temperature. When pH<pKa, the adsorption effect is much better. The adsorption isotherm of phenol on both cationic polymer/bentonites fits to the Freundlich equation.
    The midpoint diagram of trajectory in billiard systems
    LI Xiao-jun,BAI Jin-tao, LI Yong-an,
    J4. 2008, 43(9):  36-41 .  doi:
    Abstract ( 1100 )   PDF (2794KB) ( 806 )   Save
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    The midpoint diagram of trajectory in billiard systems was given. After research on several kinds of billiards, it was discovered that the midpoint diagram of several discrete points corresponds to the periodic behavior of the billiard system, the midpoint diagram of lines corresponds to quasi-periodic behavior, and the midpoint diagram of large numbers of scattered points corresponds to chaotic behavior. This indicated that the midpoint diagram can simply and efficaciously describe the dynamical behavior of the billiard system.
    On the adjacent vertex-distinguishing total coloring of some generalized Petersen graphs
    TIAN Shuang-liang
    J4. 2008, 43(9):  42-44 .  doi:
    Abstract ( 1216 )   PDF (183KB) ( 945 )   Save
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    The adjacent vertex-distinguishing total coloring of some generalized Petersen graphs G(n,r) were studied. It was constructively proved that if n≡0(mod 4), r0(mod 4) or n≡0(mod 5), r
    0(mod 5), then the adjacent vertex-distinguishing total chromatic number of
    G(n,r) is five.

    A least-squares mixed finite element procedure with the method of
    characteristics for convection-dominated Sobolev equations
    GUO Hui,LIN Chao
    J4. 2008, 43(9):  45-50 .  doi:
    Abstract ( 1020 )   PDF (245KB) ( 603 )   Save
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    A least-squares mixed finite element procedure with the method of characteristics for convection-dominated Sobolev equations was presented. By properly selecting the least-squares functional, the procedure can be split into two independent sub-procedures. The solution u and the flux σ can be obtained directly. Moreover, this method permits the use of large steps. The convergence analysis shows that the method yields the approximate solutions with optimal accuracy in L2(Ω) and H1(Ω) norms for u and H(div;Ω) norm for the flux σ.

    Positive solutions for singular m-point boundary value problems in a Banach space

    ZHANG Xing-qiu,ZHONG Qiu-yan
    J4. 2008, 43(9):  51-56 .  doi:
    Abstract ( 925 )   PDF (234KB) ( 564 )   Save
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    By constructing a particular closed convex set and applying the M[AKo¨D]nch fixed-point theorem, the existence of a positive solution for singular m-point boundary value problem φ″(x)+f(x,φ(x))=0, (0<x<1)
    φ(0)=θ,φ(1)=∑m-2i=1aiφ(ξi)
    was obtained in a Banach space.

    Incidence chromatic number and adjacent vertex-distinguishing incidence
    chromatic number of hexagonal systems
    ZHOU Wei,LIU Xi-kui,WANG Wen-li
    J4. 2008, 43(9):  57-62 .  doi:
    Abstract ( 915 )   PDF (295KB) ( 820 )   Save
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    The incidence chromatic number and adjacent vertex-distinguish incidence chromatic number of free hexagonal systems and r-corona graph in the plane were obtained by using the embedding method of graphs.

    Acyclic edge coloring of some planar graphs
    SUN Xiang-yong,WU Jian-liang
    J4. 2008, 43(9):  63-67 .  doi:
    Abstract ( 1093 )   PDF (209KB) ( 780 )   Save
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    If a planar graph G contains no i-cycles, i=3,5, and any two 4-cycles have no common edge, then the acyclic edge coloring conjecture holds. And if a planar graph G contains no 3-cycles and any two 4-cycles have no common vertex, then acyclic edge chromatic number of G is at most Δ(G)+3.
    A state-tree based (t, n) secret sharing scheme
    ZHU Yi,DAI Tao,ZHANG Xian-feng
    J4. 2008, 43(9):  68-72 .  doi:
    Abstract ( 955 )   PDF (256KB) ( 782 )   Save
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    By introducing and analyzing the existed threshold secret sharing schemes, a visual, concise and efficient state-tree based (t, n) secret sharing scheme was proposed and analyzed, including designing consideration, algorithm description and algorithm instance. It was shown that the secret split algorithm of the scheme polynomial complexity and the secret reconstruction algorithm have linear complexity. This scheme can provide threshold confidentiality and threshold availability.
    A wide-neighborhood predictor-corrector algorithm for convex quadratic programming
    ZHOU Yi-yuan,ZHANG Ming-wang*,LU¨ Yan-li,ZHAO Yu-qin
    J4. 2008, 43(9):  73-80 .  doi:
    Abstract ( 1107 )   PDF (263KB) ( 805 )   Save
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    Zhao presented a wide-neighborhood predictor-corrector algorithm for linear programming via the least values of proximity measure functions, and he also proved the algorithm has the polynomial iteration complexity. Zhao′s algorithm was extended to convex quadratic programming and a new wide-neighborhood predictor-corrector algorithm was presented based on the minimums of proximity measure functions. Since the new search direction Δx and Δs are no longer orthogonal, the convergence analysis is different from that of the linear programming. The new algorithm has been proved to retain the sofar best known iteration complexity of Onln(x0)Ts0ε iterations. Moreover, a rough numerical experiment shows the feasibility and efficiency of this new algorithm.
    Eigenvalue problems of bi-harmonic equations with Hardy potential
    WU Yun,YAO Yang-xin,KE Min
    J4. 2008, 43(9):  81-84 .  doi:
    Abstract ( 824 )   PDF (174KB) ( 690 )   Save
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    The eigenvalue problem of bi-harmonic equations with Hardy potential 1/|x|4 (N≥5) was investigated based on an establishment of a new space and a Hardy-Rellich inequality. Furthermore, the results show the solvability of these problems in the new space.

    Linear incentive mechanism of distributor in Cournot duopoly market
    WANG Zhen,JIANG Peng-fei
    J4. 2008, 43(9):  85-88 .  doi:
    Abstract ( 1012 )   PDF (221KB) ( 867 )   Save
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    How does the manufacturer introduce an incentive mechanism to the downriver distributor to constitute his supply chain and then gain competition advantage in Cournot two-duopoly market was analyzed. The Cournot games and incentive models between a supply chain and a manufacturer and between two supply chains were constituted. The optimal incentive strategy of the manufacturer, which is the dominant enterprise in the supply chain, was solved both under the single-side incentive and double-side incentive conditions. Then the influence to the players′ payoff and market share were discussed.
    The inexact Newton method for inverse Toeplitz eigenvalue problems
    CHEN Bei
    J4. 2008, 43(9):  89-93 .  doi:
    Abstract ( 1019 )   PDF (226KB) ( 771 )   Save
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    Numerical methods for solving large inverse Toeplitz eigenvalue problems were studied. The inexact Newton method for solving large inverse Toeplitz eigenvalue problem was given by using iterative methods(inner iterations) for solving these systems approximately. This method can avoid the oversolving problems of Newton methods and hence improve the efficiency. The numerical results show that the inexact Newton method is better than the Newton method.
    On solutions of Pocklington equation in Z[w]
    WANG Yong-liang
    J4. 2008, 43(9):  94-96 .  doi:
    Abstract ( 743 )   PDF (175KB) ( 789 )   Save
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    All solutions of Pocklington equation in Z[w] were determined,which implies that the equation has only trivial soluyions in tjis ring.