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Table of Content

      
    24 January 2007
    Volume 42 Issue 1
    Articles
    Function S-rough sets and discovery of investment risk F-laws
    SHI Kai-quan
    J4. 2007, 42(1):  1-7 .  doi:
    Abstract ( 1109 )   PDF (269KB) ( 1092 )   Save
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    Using function S-rough sets, it gives the concepts of f-heredity of f-heredity laws,generation of f-heredity laws, F-heredity of function one direction singular rough sets and F-law heredity generation. The envelope theorem of F-heredity law and separation theorem of F-transfer law are presenten. It puts forwards the function one diretion S-rough sets. discovery and applications of investment risk F-laws by using these results.
    The limitation theorem of g-supersolution for BSDEs under non-Lipschitzian coefficient
    HAN Bao-yan,ZHU Bo and SHI Yu-feng
    J4. 2007, 42(1):  8-13 .  doi:
    Abstract ( 1243 )   PDF (217KB) ( 1287 )   Save
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    A limitation theorem of g-supersolution for BSDEs under non-Lipschitzian coefficient is proved. In order to get the result, the existence and uniqueness of the solution for a class of BSDEs with the same drift coefficient g are investigated, and the comparison theorem is obtained.
    Positive solutions of the nonlinear singular impulsive
    TANG Qiu-yun,YANG Jin and LIU Yan-sheng
    J4. 2007, 42(1):  14-18 .  doi:
    Abstract ( 1031 )   PDF (216KB) ( 1232 )   Save
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    Using the fixed point theorem on cones, some results are obtained on the existence of at least one and multiple positive solutions for nonlinear singular impulsive boundary value problems in Banach space.
    The alternating group iterative method for the dispersive equation
    LIU Hong-hua
    J4. 2007, 42(1):  19-23 .  doi:
    Abstract ( 1124 )   PDF (391KB) ( 1149 )   Save
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    The alternating group iterative method for the dispersive equation with periodic boundary condition is presented. A twolevel implicit difference scheme is designed, and an alternating group iterative method is suggested which is capable of parallelism on parallel computer. In addition, unconditional stability of the difference scheme and convergence of the iterative process are proved. The alternating group iterative method is used to solve the implicit scheme and the Crank-Nicolson scheme of the dispersive equation. The results show that this method has good accuracy and practicability.
    LMI approach to design the robust fault diagnosis residual generator for the singular systems based on the state observer
    CHEN Li,
    J4. 2007, 42(1):  24-27 .  doi:
    Abstract ( 971 )   PDF (219KB) ( 974 )   Save
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    The robust fault detection filter design for singular systems with uncertain disturbance is studied. From the viewpoint of L2gain, the state observerbased robust fault detection filter design for singular systems is formulated as an H optimization problem, and is further solved by suitably selecting weighting matrix and observer coefficient matrix, which can maximize the sensitivity of fault residual and simultaneously guarantee the robustness of uncertain disturbance residual. The solvable conditions of this optimization problem and the solutions are derived by employing linear matrix inequality techniques.
    Multitypeinsurance poisson risk model when claims obey exponential distribution
    ZHOU Shao-wei,ZHAO Ming-qing and ZHU Zhe-li
    J4. 2007, 42(1):  28-30 .  doi:
    Abstract ( 1079 )   PDF (193KB) ( 1161 )   Save
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    A multitypeinsurance poisson risk model is constructed. The differential function of ruin probability and the expression for Ψ(0) is given. The expression for Ψ(u) when claims obey exponential distribution is also put forward.
    τ-Flat test modules and τ-flatcover
    FENG Xiao and ZHANG Shun-hua
    J4. 2007, 42(1):  31-34 .  doi:
    Abstract ( 871 )   PDF (189KB) ( 1362 )   Save
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    The existence of τ-flat test modules is proved, and some sufficient conditions for {τ-flat left R-modules} being preenvelope class or precove class are obtained.
    The fractional nonlinear convection-diffusion equation and its solution
    LIU Yan-qin,XU Ming-yu and JIANG Xiao-yun
    J4. 2007, 42(1):  35-39 .  doi:
    Abstract ( 1135 )   PDF (234KB) ( 1009 )   Save
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    Fractional nonlinear convectiondiffusion equation with external forces is given. First, the integer equation is studied by considering the diffusion coefficient D(x)∝xθ. By using the q-exponential function and q-logarithm function, the analytical solution of the equation is derived. Second, a fractional equation with absorption is analyzed. On condition that the nonlinear parameters satisfy certain relationships, a special solution can be obtained. In addition, the asymptotic behaviors for the solution are also discussed.
    A constructing method for completely regular semigroup
    BI Xiao-dong
    J4. 2007, 42(1):  40-43 .  doi:
    Abstract ( 973 )   PDF (188KB) ( 982 )   Save
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    A constructing method for completely regular semigroup is offered by using completely simple semigroup, semilattice and constructing functions. Furthermore, the relation between homomorphism of completely regular semigroups and constructing functions is discussed. Constructing functions of spinning product of completely regular semigroups are considered.
    The maximum principle for fully coupled forwardbackward stochastic control system with state constraints
    SHI Jing-tao
    J4. 2007, 42(1):  44-48 .  doi:
    Abstract ( 898 )   PDF (237KB) ( 1185 )   Save
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    The maximum principle for fully coupled forwardbackward stochastic control system with state constraints is presented under the assumption that the forward diffusion coefficient does not contain the control variable, while the control domain allows unconvex.
    System capacity and filter design of filtered multitone modulation
    ZHU Wei-hong,ZHANG Bing-feng and GAO Zhen-ming
    J4. 2007, 42(1):  49-54 .  doi:
    Abstract ( 1109 )   PDF (451KB) ( 1247 )   Save
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    The capacity of the filtered multitone modulation system is theoretically analyzed. It is shown that characteristics of the prototype filter mainly decide the system capacity. Design strategies of the prototype filter are presented. Simulation results show that the achievable bit rates of the uncoding system could reach 10 Mbps under the circumstances that the capacity of filtered multitone modulation system is 802.11a.
    Analysis and improvement of Wang threshold signature scheme
    LI Guo-wei,LI Ru-peng and LI Da-xing
    J4. 2007, 42(1):  55-58 .  doi:
    Abstract ( 1013 )   PDF (229KB) ( 1134 )   Save
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    Based on security analysis of Wang's threshold signature scheme, it is pointed out that only the partial private key is valid in the scheme. A simplified scheme is proposed, of which the security is equal to the one of the rectified Wang's scheme. Both schemes are vulnerable to universal forgery by an insider attacker because their underlying signature schemes are unfit for threshold signature. Then a solution is given for this problem.
    Synthesis of polystyrene with 1,1diphenylethene pendant groups via atom transfer radical polymerization
    LAI Ai-xiang,LU Zai-jun
    J4. 2007, 42(1):  59-63 .  doi:
    Abstract ( 1053 )   PDF (270KB) ( 1359 )   Save
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    Polystyrenes with 1,1diphenylethene (DPE) pendent groups were synthesized via atom transfer radical polymerization (ATRP). ATRP of 4-vinylbenzyloxy benzophenone led to the formation of polystyrenes with benzophenone pendant groups. Then, the benzophenone pendant groups were converted to DPE pendent groups by Wittig reaction to yield the desired polymer. The resulting polymers and their precursors were characterized by 1H NMR,IR,and GPC measurements in detail. The results show that the polymers have DPE pendant groups, controllable molecular weight, and a narrow molecular weight distribution.
    Influences of immobilization microenvironment on Taxus chinensis var.mairei cell growth and taxol synthesis
    YIN De-ming,YUAN Ying-jin,LOU Hong-xiang
    J4. 2007, 42(1):  64-68 .  doi:
    Abstract ( 1075 )   PDF (297KB) ( 986 )   Save
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    Cell growth and taxol synthesis of Taxus chinensis var. mairei were investigated under the immobilization microenvironment. The results show that the stagnation period of immobilizedcell is shortened. Lipoxygenase activity and malondialdehyde content of immobilizedcell are significantly higher than those of suspendedcell. Both phenylalanine ammonialyase activity of immobilizedcell and extracelluar taxol content in the microenvironment show a marked increase. An immobilization microenvironment can promote taxol content and peroxidize the cell membrane lipid.
    Study on the water-holding ability of the litter in different mixed forest of Tumen Plantation of Xintai
    LI Yan-cheng,CHENG Chun-min ,YANG Ji-hua*,WANG Xing-cui and LIU Pei-juan
    J4. 2007, 42(1):  69-75 .  doi:
    Abstract ( 1180 )   PDF (265KB) ( 1285 )   Save
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    Water-holding ability of 7 types of forests in Tumen Plantation was studied. Results show that the storage capacity of litter layer of the different forests is from 1.48 to 10.08t·hm-2. The Robinia pseudoacacia Linn. and Quecus variabilis Carr. mixed forest have the highest storage capacity and the Vitex negundo Linn. has the lowest. The largest retaining content and the effective retaining content is ranging from 0.48mm to 2.99mm and from 0.39mm to 2.47mm respectively. The largest retaining content and the largest effective retaining content of the Robinia pseudoacacia Linn. and Quecus variabilis Carr. mixed forest are the highest ones and the Pinus tabuleaformis Carr. pure forest is the lowest. The soil moisture and the saturated waterstorage capacity in 0~40cm soil layer are both in declining order: the Robinia pseudoacacia Linn and Quecus variabilis Carr. mixed forest, Robinia pseudoacacia Linn pure forest, Quecus variabilis Carr. pure forest, the Quecus variabilis Carr. and Pinus tabuleaformis Carr. mixed forest, Pinus tabulaeformis Carr. and Viex negundo mixed forest, Pinus tabulaeformis Carr. pure forest, Viex negundo pure forest, and bare field.
    Allee effect and its significance to small population management in nature reservation and biological invasions
    QANG Yao,LIU Jian and WANG Ren-qing,*
    J4. 2007, 42(1):  76-82 .  doi:
    Abstract ( 1249 )   PDF (356KB) ( 1416 )   Save
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    Habitat fragmentation, as a result of human activities, is a great threat to biodiversity. Many small populations emerge after habitat fragmentation. Their extinction rate may be accelerated by Allee effect. The Allee effect may also occur during biological invasions, which results to increasing attentions paid to its effect on invasive species. The definition, function and reasons of Allee effect were introduced. It is shown that Allee effect occurs at the beginning of species invasion, which influences the spread speed, spread strategies and even survive of the invasive species in the new habitat. The application of Allee effect to small population management was discussed in relation to preventing biological invasions and protecting rare species.
    Quantitative analysis of structure and biodiversity of shrub layer and herbage layer under forest community at Kunyu Mountain
    WU Da-qian,DU Ning,WANG Wei,ZHAI Wen,WANG Yu-feng,WANG Ren-qing and ZHANG Zhi-guo*
    J4. 2007, 42(1):  83-88 .  doi:
    Abstract ( 1071 )   PDF (516KB) ( 1383 )   Save
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    The TWINSPAN classification and DCA ordination were employed for the quantitative analysis of the shrub layer and herbage layer under different stands. The shrub layer and herbage layer were classified into 14 and 10 types by the TWINSPAN classification method, which indicated that classified types of the shrub layer and herbage layer highly correspond to the type of the stand. The quadrats of the shrub layer and herbage layer were both coordinated into four ecological types in the space of the DCA ordination. The foremost environmental factors in the DCA ordination of shrub layer is illumination and moisture, while for the herbage layer it is moisture. Under different stands, not all the biodiversity indices are significantly different, while the Gleason index and Shannon-Wiener index are significantly different among different stand types.
    Enhancement of drought resistance in transgenic tobacco expressing sucrose: Sucrose 1-fructosyltransferase gene from Lactuca sativa
    LI Hui-juan,YIN Hai-ying,ZHANG Xue-cheng and YANG Ai-fang*
    J4. 2007, 42(1):  89-94 .  doi:
    Abstract ( 1196 )   PDF (726KB) ( 1305 )   Save
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    Sucrose: sucrose 1-fructosyltransferase catalyses the synthesis of 1-kestose by transferring a fructosyl moiety from one sucrose to another. A full-length cDNA encoding sucrose: sucrose 1-fructosyltransferase from Lactuca sativa was inserted into pCAMBIA1300-als under the control of the CaMV 35S promoter. This plasmid was used for Agrobacteriummediated tobacco leaf disc transformation. Transgenic plants were analyzed by PCR and Southern blotting. 1-SST gene expression was confirmed by RT-PCR. After 6 days without watering, electrolyte leakage and malondialdehyde (MDA) of T0 transgenic tobacco are obviously lower than those of the wild type. Significant decreases of relative water content (RWC) are detected in wild type tobacco, when compared with transgenic tobacco. According to carbohydrate analysis, the fructan of transgenic tobacco is detected and not in the wild type. Fructan content of transgenic tobacco is significantly increased after drought stress. Seed germination rate of wild type tobacco is 50% of that of transgenic tobacco under 14% PEG treatment. Root development of transgenic tobacco is not affected while that of wild type tobacco is inhibited when they were cultured in 200 mmol/L mannitol. These results indicate that fructan might be related to tobacco's drought tolerance.