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Table of Content

      
    24 January 2009
    Volume 44 Issue 1
    Articles
    Identification of strain F3 producing transglycosyl β-galactosidase and the  optimization of fermentation and galactosylation
    LI Yu-mei, LU Li-li, XIAO Min
    J4. 2009, 44(1):  1-6 .  doi:
    Abstract ( 959 )   PDF (637KB) ( 1046 )   Save
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    Strain F3 was isolated from soil and produced transglycosyl βgalactosidase. It was identified as Penicillum expansum F3 by means of morphological characteristics and 18S rDNA sequence analysis. Medium and fermentation conditions for its βgalactosidase production were optimized by single factor and orthogonal experiments. The final yield of the enzyme reached 2?245.2?U/L in the medium composed of 2% glucose,1% yeast extract, 1.5% peptone and 0.3% NaCl at initial pH 6.0 and 28?℃ for 40?h, which increased threefold compare to before optimization. The effects of pH, temperature and time on galactooligosaccharides (GOS) synthesis were investigated. A purity of 30.6% (w/w) GOS was obtained from 30% lactose solution at pH 4.5 and 50?℃ for 24?h. Transgalactosyl trisaccharides were the main products, accounting for more than 80% of the GOS product.

    Comparison of the portable steady porometer method and standard branch soaking method for the measurement of poplar's water consumption by transpiration
    LI Yancheng1, YANG Jihua2, FANG Yong3, WANG Yuehai3, CHEN Anqiang2
    J4. 2009, 44(1):  7-11 .  doi:
    Abstract ( 1144 )   Save
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    In order to use the standard branch soaking method to calibrate the rate of water consumption by the portable steady porometer method to measure transpiration, the rates of water consumption by transpiration eight 4yearold poplar clones were measured by a portable steady porometer method and standard branch soaking method in the nursery garden of the forestry bureau of Gaomi City in May, 2008. The results showed that the rate of water consumption by transpiration measured by these two methods for a daily changing tendency was a singleapex curve. The rate of water consumption by transpiration measured with the portable steady state porometer method was always higher than the standard branch soaking method. The difference of the ratios of measured value between the two methods was not obvious when the transpiration rate was lower in the morning and evening, but the difference increased with relative humidity decreasing, and the light, temperature and transpiration rate increasing. The rate of water consumption by transpiration was linear by these two measured methods,(correlation coefficient, R2>0.8), and the correlation was significant. This study can be used to correct the poplar's water consumption by transpiration measured by the portable steady porometer method.

    无栏目
    Effect on polluted water purification by eight emergent plants
    SUN Ruilian 1,2, ZHANG Jian 3, WANG Wenxing 1
    J4. 2009, 44(1):  12-16 .  doi:
    Abstract ( 890 )   PDF (333KB) ( 925 )   Save
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    Potculture experiments were conducted to study the effects of eight emergent plants on purifying polluted water under different hydraulic retention times. Results showed that the purifying effects on pollutants were different among eight emergent plants and removal efficiency increased with hydraulic retention time. All plants had significant improvement for COD removal except Sparganium stenophyllum Maxim, when hydraulic retention time was 5 days. The COD removal efficiencies of Acorus calamus L., Scirpus validus Vahl, Typha latifolia L. and Iris wilsonii C. H. Wright were all about 90%, which were higher than those of the other plants. When the hydraulic retention time was 7 days, the removal efficiencies of eight plants for NH+4N and TN increased by 15.0%~41.8% and 6.7%~25.1% respectively as compared with the control. Iris wilsonii C. H. Wright, Zizania latifolia Turcz. and Typha latifolia L. showed excellent removal capacities of NH+4N and TN. TP removal efficiencies by Zizania latifolia Turcz. and Typha latifolia L. were significantly higher than that of control, the increased removal efficiencies for TP were 10.8% and 11.2% respectively. These results indicated that Iris wilsonii C. H. Wright, Zizania latifolia Turcz. and Typha latifolia L. could be selected for constructing wetland hydrophytes in Nansi Lake.
    Quantitative determination of the functional groups on multiwalled carbon nanotubes
    LI Xiaofeng, WANG Fang, ZHANG Bin
    J4. 2009, 44(1):  17-23 .  doi:
    Abstract ( 775 )   PDF (982KB) ( 1044 )   Save
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    Abstract: Carbon nanotubes (CNTs) have attracted much attention in the fields of chemistry, physics, biology and material science due to their unique structure and physical and

    chemical properties. Although there have been many technologies to characterize CNTs qualitatively, for example, TEM, SEM, AFM and Raman spectra, quantitative assays for

    functional groups lag behind. Moreover, the reported results mainly focused on singlewalled carbon nanotubes (SWNTs). Systemic quantitative research for multiwalled carbon

    nanotubes (MWNTs) has not been appeared so far. In this research, carboxylic MWNTs, amino MWNTs and carboxylic C60 were first synthesized. The carboxylic and amino groups were

    separately quantified with acidbase titration and the DeFmoc group method. It was found that the acidbase titration method is an accurate method to quantify the

    carboxylic groups on MWNTs, and the DeFmoc group method can simply and accurately determine the density of amino groups on functional MWNTs.

    WU Yuanhui1,2, LIU Tianmo1, LUO Suxing2, SUN Cheng3
    J4. 2009, 44(1):  24-27 .  doi:
    Abstract ( 1149 )   PDF (574KB) ( 1230 )   Save
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    Macrocell corrosion of X70 steel in soils was studied by using weight loss and electrochemical impedance spectroscopy (EIS). It was found that the corrosion rate of anode in

    clay was 307 times of that in natural condition. When the area ratio of cathode to anode was 15:1, the corrosion rate of the anode in clay was 210 times of that in condition

    of the area ratio of cathode to anode being 1∶1. During the test, the corrosion rate of X70 steel in clay, which was buried, was slow, but the anode of the macrocell kept a

    rapid corrosion rate.

    Some notes on the communication process decision tree
    CHEN Lei
    J4. 2009, 44(1):  33-39 .  doi:
    Abstract ( 1376 )   PDF (1200KB) ( 826 )   Save
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    The statistical model of the communication modes has established the theoretical foundation for pansynchronous communication on a 2dimenssional network, based on which some trial applications have been started. The strict formal definition of the communication process decision tree and the inductive definition of the time dependent equal tipprobability tree, and concepts of full symmetric, full, uniform, semiuniform, almost semiuniform were derived. A discussion of the relation of probability distribution of tips and probability distributions of segments at each node was presented, and two theorems were proved. These definitions and concepts will set the theoretical framework for generating communication modes by artificial intelligence in the future.
    An efficient IDbased proxy ring signature scheme
    WU Lei 1, KONG Fanyu 2
    J4. 2009, 44(1):  40-43 .  doi:
    Abstract ( 1166 )   PDF (233KB) ( 848 )   Save
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    In a proxy signature scheme, a potential signer delegates his signing power to a proxy, who signs a message on behalf of the original signer. The ring signature allows a user from a set of possible signers to convince the verifier that the author of the signature belongs to the set but the identity of the author is not disclosed. A new efficient IDbased proxy ring signature scheme was proposed based on the advantages of proxy signature and ring signature. Its security and efficiency was also discussed. Compared with Zhang’s scheme and Amit’s scheme, the new scheme has better computational efficiency.
    Linear maps preserving Jacobi identity on the full matrix algebras
    WU Xiaogui, ZHANG Jianhua
    J4. 2009, 44(1):  49-52 .  doi:
    Abstract ( 1199 )   PDF (185KB) ( 620 )   Save
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    Let R be a 2torsionfree commutative prime ring with a unity, and Mn(R)(n≥4) be the algebra consisting of all n×n matrices over R. First, the definition of maps preserving Jacobi identity was given, and then their properties were investigated. The main purpose of this paper is to present a concrete form of such kind of maps.

    ZHANG Wei, JU Peijun
    J4. 2009, 44(1):  63-66 .  doi:
    Abstract ( 828 )   PDF (295KB) ( 532 )   Save
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    The existence results for fourthorder twopoint boundary value problems
    XI Jinhua
    J4. 2009, 44(1):  67-73 .  doi:
    Abstract ( 978 )   PDF (229KB) ( 789 )   Save
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    x(4)=f(t,x,x′,x″,x) ,
    boundary value condition
    were considered and results were obtained, here the boundary value condition is one of the followings:
    x(0)=A,x(1)=B,x″(0)=,x″(1)=,
    x(0)=A,x(1)=B,x″(0)=,x(1)=,
    x(0)=A,x(1)=B,x(0)=,x″(1)=,
    x(0)=A,x′(1)=B,x″(0)=,x″(1)=,
    x(0)=A,x′(1)=B,x″(0)=,x(1)=,
    x(0)=A,x′(1)=B,x(0)=,x″(1)=,
    x′(0)=A,x(1)=B,x″(0)=,x″(1)=,
    x′(0)=A,x(1)=B,x″(0)=,x(1)=,
    x′(0)=A,x(1)=B,x(0)=,x″(1)=.

    These results were given to assume that the function f(t,x,y,p,r) satisfies the following condition. There are pairs (four or eight) of suitable constants such that f(t,x,y,p,r) does not change sign on sets of the form [0,1]×Dx×Dy×Dp×I, where Dx, Dy, Dp are closed bounded intervals, I is a closed set in R and bounded by some pairs of constants, mentioned above.

    Uniform integrability of sequences of fuzzy valued functions
    LI Yanhong
    J4. 2009, 44(1):  74-77 .  doi:
    Abstract ( 821 )   PDF (216KB) ( 577 )   Save
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    By the introduction of a new multiplying operator, fuzzy valued integrals were defined to aim at fuzzy valued functions. On this basis the necessary and sufficient conditions to the uniform integrability of sequences of fuzzy valued functions were given, and the implication relations between uniform integrability of sequences of fuzzy valued functions and the uniformly boundedness of the their fuzzy valued integrals were studied.
    The distribution of propositional truth degree in 5valued logic systems
    associated with a nonlinear ordering true value set
    SUI Yunyun
    J4. 2009, 44(1):  78-82 .  doi:
    Abstract ( 1158 )   PDF (220KB) ( 987 )   Save
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    Base on the infinite product of evenly distributed probability space with cardinality of 5, the theory of truth degrees in 5valued logic systems associated with a nonlinear ordering true value set was introduced. Some inference rules were given. It was proved that the set of truth degree of propositions is dense in [0,1], and the expressions of truth degree were obtained. Therefore a possible framework for establishing approximate reasoning theory of 5valued propositional logic systems L25 was proposed.
    implicit image generationidentification
    ZHOU Houyong 1,2, SHI Kaiquan 2
    J4. 2009, 44(1):  91-96 .  doi:
    Abstract ( 929 )   PDF (317KB) ( 805 )   Save
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    By using function Srough sets, the image generation was given. The concept of implicit image, and the structure and its attribute characteristic of implicit image were presented, and the separation theorem and reduction theorem of implicit image were proposed. Finally, the application of implicit image in an image information system was given.