Loading...

Table of Content

    25 January 2012, Volume 2012 Issue 1 Previous Issue    Next Issue
    For Selected: Toggle Thumbnails
    Article
    Phytoremediation of heavy metals and rhizosphere detection of bacteria in a drainage river sediment
    WANG Lei, QI Pei-shi, XIN Ming
    2012, 2012 (1):  1-10, 36. 
    Abstract ( 3082 )   PDF (4068KB) ( 2426 )   Save
    Concentrations of heavy metals (Pb, Zn, Cr, As, Ni, Cu and Cd) in a drainage river sediment were determined from the industrial area of Harbin city in Heilongjiang Province. Pot experiment was conducted to evaluate the potential of four spontaneous plants, 〖WTBX〗Zea mays 〖WTBZ〗L., 〖WTBX〗Polygonum lapathifolium 〖WTBZ〗L., 〖WTBX〗Solanum nigrum〖WTBZ〗 L. and 〖WTBX〗Rumex patientia〖WTBZ〗 L. for heavy metals phytoremediation in the drainage river sediment contaminated with industrial effluent. The results revealed that the sediment was polluted by heavy metals. The contents of residual fractions of the 7 heavy metals decreased, while the Fe-Mn oxide fractions and exchangeable fractions consistently increased via two-season cultivations. Sequential extraction results confirmed the capability of the four plants to increase the bioavailability of these heavy metals. The concentrations of heavy metals in sediments and plants were in the same trend: Zn>Pb >Ni>Cr>Cu>As>Cd, which reflected the biomonitoring potentialities of the tested plants. The heavy metals accumulations and translocations of the four plants were investigated. The results showed that the plants accumulated more Zn and Ni than the other metals; and the concentrations of Cu in shoots were low. Zinc and Ni levels in plant samples ranged from 108.4 mg/kg in shoots to 543.92 mg/kg in roots and 36.8 mg/kg in shoots to 246.91 mg/kg in roots of different species, respectively. Generally, the four species excluded multiple metals from the shoot tissues and accumulated in root zones, behaving as tolerant plants. However, polygonum lapathifolium L., Rumex patientia L. and Solanum nigrum L. showed high Pb, Zn and Cd shoot accumulation with high metal translocation factor (TF>1), respectively. It suggested the three species had phytoextraction potentialities. In addition, florescence in situ hybridization (FISH) was used to analyze the amount and distribution of bacteria in the rhizosphere sediment. It suggested the four plants have effect on bacterial activations.
    References | Related Articles | Metrics
    Influence of nitrogen and phosphorus concentrations on the growth characteristics of Microcystis aeruginosa
    ZHENG Xiao-yu, JIN Yan, REN Xiang-yu, GU Yong-jie,ZHU Yong-qing, YANG yi-fan
    2012, 2012 (1):  11-18. 
    Abstract ( 2962 )   PDF (1477KB) ( 2431 )   Save
    Microystis aeruginosa was cultured in solutions of different initial nitrogen and phosphorus concentrations. The semi-saturation constants (Ks) of Microystis aeruginosa to P and N were calculated respectively by using the Monod equation. The results show that the Microystis aeruginosa grew normally when the concentrations of N and P were greater than 4.0 mg·L-1 and mg·L-1 respectively. The optimum concentration ranges of N and P for Microystis aeruginosa growth were 32.0~64.0 mg·L-1 and 1.0~1.50 mg·L-1 respectively. KsN is higher than Ksp,  which indicates that the affinity of P to Microystis aeruginosa is higher than N. When the concentration ranges of N and P were 0.20~64.0 mg·L-1 and 0.02~1.50 mg·L-1 respectively,they had high liner correlation with the largest extent quantity of Microystis aeruginosa. The special growth rate increases continuously when the concentration ranges of N and P are 0.20~1.60 mg·L-1 and 0.02~0.50 mg·L-1 respectively.
    References | Related Articles | Metrics
    Experimental study on the adaptability of juvenile Myxocyprinus asiaticus to the estuarine waters
    WANG Feng-yi, LU Jian-jian
    2012, 2012 (1):  19-26. 
    Abstract ( 2103 )   PDF (2543KB) ( 2261 )   Save
    The adaptability of juvenile Myxocyprinus asiaticus to the estuarine waters was experimentally studied by investigating the survival ratios, the superoxide dismutase (SOD) activities in its' liver, the Na+/K+-ATPase activities response in its’ gill to different salinity stresses and joint stresses of nitrate and phosphate. The result showed that, the survival was 100% when the salinity was below 10.There were not significant differences of the SOD activities and the Na+/K+-ATPase activities between salinities 3 and 0 (p>0.05), respectively. The survival was 100% when the water quality was better than Ⅳ. The SOD activities and the Na+/K+-ATPase activities in water quality Ⅳ was higher than that in Ⅱ and Ⅲ (p<0.05). In conclusion, juvenile Myxocyprinus asiaticus have strong adaptability when the salinity is below than 3 and water quality is superior to Ⅲ, and that means that the current environmental situation at the upper section of Yangtze Estuary can provide juvenile Myxocyprinus asiaticus with adaptive water quality to live.
    References | Related Articles | Metrics
    Chlorinity distribution and water intake operation of the Chenhang Reservoir during saltwater intrusions in the Yangtze Estuary
    SHEN Yi-chen, LI Lu, ZHU Jian-rong
    2012, 2012 (1):  27-36. 
    Abstract ( 2172 )   PDF (4209KB) ( 2513 )   Save
    In order to supply water during severe saltwater intrusions in the Yangtze Estuary, the Chenhang Reservoir sometimes took brackish water. The chlorinity in the reservoir was measured during November 27 in 2009 to March 12 in 2010. Combined with the river discharge, water level, wind stress, chlorinity at the upstream station and its inlet,the saltwater intrusion in the estuary, the way of water intake operation, and temporal/spatial variations of the chlorinity in the reservoir were analyzed. The simulated results showed that, the upstream was tended to be present around its eastern coastline under westward wind. Before the brackish water reached the reservoir, the amount of the water intake was increased to make it to high water level. At the beginning of a saltwater intrusion, the reservoir took the brackish water to keep its higher water level. In the later of the saltwater intrusion, some freshwater was taken from the Baogang Reservoir and the amount depended on the intensity of saltwater intrusion. Furthermore, the water intake from the Yangtze River must be paused when the chlorinity at the supply outlet in the reservoir was close to 250 mg/L. The measured data indicated that the chlorinity of the reservoir was increased when the brackish water in-taking was conducted and experienced a spatial variation under different wind stresses. The water intake operation of the Chenhang Reservoir was dependent on the chlorinity inside/outside it. In addition, its water level, the chlorinity in its upstream as well as the wind stress should also be taken into account. This study can bring experience to the reservoirs built in estuaries for better operation.
    References | Related Articles | Metrics
    Modeling of seawater reflectance in the Yangtze Estuary and the adjacent sea
    HONG Guan-lin, SHEN Fang, SHEN Hong
    2012, 2012 (1):  37-46. 
    Abstract ( 2909 )   PDF (3551KB) ( 2644 )   Save
    The optical properties of the Yangtze Estuarine waters were discussed based on two investigations conducted respectively in August and November of 2009. It was found that the water-leaving reflectance spectra in August and November presented four types caused by different chlorophyll-a concentrations, suspended sediment concentrations and colored dissolved organic matters (CDOM). The relationships between chlorophyll-a concentration and absorption coefficient of the pigment particles were built by two ways, and two models used to simulate the reflectance spectra were established by using the parameterized optical properties, the RMSE of these models being 0.004 4 and 0.004 5, respectively. The accuracy of the model can be improved by classifying the concentrations of chlorophyll-a and suspended sediment, the RMSE was improved to 0.003 5.
    References | Related Articles | Metrics
    Long-term potentiation of prefrontal cortex in NR1 knockout mice
    YANG Li-guo, ZENG Qing-wen, ZHANG Xu-liang, CAO Xiao-hua
    2012, 2012 (1):  47-53. 
    Abstract ( 2796 )   PDF (1731KB) ( 2646 )   Save
    This study investigated the prefrontal synaptic plasticity of forebrain-specific NR1 knockout mice by using the vitro field potential recording technique. The results from the input-output and paired pulse depression curves suggest that the basal synaptic transmission is normal in the prefrontal cortex of NR1 knockout mice. Prefrontal long-term potentiation (LTP) induced by high frequency stimulation (two trains of 100 Hz with 1 s duration and 30 s interval) was abolished in slices of NR1 knockout mice. These results indicate that NR1 is critical in the induction of long-term potentiation in prefrontal cortex.
    References | Related Articles | Metrics
    βCaMKII overexpression impairs long-term depression in dentate gyrus of mice
    XU Hao, WANG Bo, DUAN Yan-hong, CAO Xiao-hua
    2012, 2012 (1):  54-62. 
    Abstract ( 2584 )   PDF (1356KB) ( 2872 )   Save
    This experiment was designed to investigate the effects of the βCaMKII on the long-term depression (LTD) in dentate gyrus(DG)by using the transgenic mice in which the overexpression of βCaMKII is restricted to the DG area. Compared to the control group, the paired-pulse depression curve and voltage-current response in DG of transgenic mice didn’t change, but the LTD was significantly reduced. These results suggest that overexpression of the βCaMKII may impair the long-term depression without effect on the presynaptic function and passive properties of granule cells in DG area.
    References | Related Articles | Metrics
     $\lambda$ point and $\lambda$ property in generalized Orlicz spaces with Luxemburg norm
    SHI Zhong-rui, ZHAI Jia-yu
    2012, 2012 (1):  63-73. 
    Abstract ( 2194 )   PDF (219KB) ( 2295 )   Save
    In this paper, we gave the sufficient and necessary conditions of $\lambda$ point in a generalized Orlicz function space equipped with the Luxemburg norm, by methods used in classical Orlicz spaces and new methods introduced especially for generalized ones. The results indicate the difference between points in the unit balls of classical and that of generalized Orlicz spaces: all of the classical spaces are $\lambda$ points, but some of the generalized spaces are not. Finally, we gave the criteria of the $\lambda$ property and the uniform $\lambda$ property of generalized spaces.
    References | Related Articles | Metrics
    System of variational inclusions with ${(\emph{\textbf{H}},{\bm\phi})}$-$\bm\eta$-monotone operators in Banach spaces
    ZHANG Chao
    2012, 2012 (1):  74-83. 
    Abstract ( 2795 )   PDF (202KB) ( 2260 )   Save
    This paper introduced a new system of variational inclusions with $(H,\phi)$-$\eta$-monotone operators in real uniformly smooth Banach spaces. By using the proximal mapping technique associated with $(H,\phi)$-$\eta$-monotone operators, we proved the existence and uniqueness of solution for this new system and construct a new iterative algorithm for approximating the solution of this system. The convergence of the iterative sequence generated by the iterative algorithm was also discussed. The results extend and improve some known results in the literature.
    References | Related Articles | Metrics
    A graph \emph{G} is said to be \emph{determined by its spectrum} if any graph having the same spectrum as that of \emph{G} is isomorphic to \emph{G}. In this paper, it was proved that $K_{n}-E(lP_{2}) $ and $K_{n}-E(K_{1,l})$ are determined by their spectra, respectively.
    WU Ting-zeng, HU Sheng-biao
    2012, 2012 (1):  84-87. 
    Abstract ( 2270 )   PDF (162KB) ( 2139 )   Save
    A graph \emph{G} is said to be \emph{determined by its spectrum} if any graph having the same spectrum as that of \emph{G} is isomorphic to \emph{G}. In this paper, it was proved that $K_{n}-E(lP_{2}) $ and $K_{n}-E(K_{1,l})$ are determined by their spectra, respectively.
    References | Related Articles | Metrics
    Proofs and applications for a combinatorial identity
    SHI Jian-yi, WANG Wei
    2012, 2012 (1):  88-96. 
    Abstract ( 2412 )   PDF (408KB) ( 2177 )   Save
    This paper considered a combinatorial identity related to some combinatorial enumeration problems involving the number $n^{n-2}$. The identity was proved in three different ways, which were in the theory of functions of complex variables, in graph theory, and in combinatorics, respectively. Finally, the identity was applied to enumerate certain kind of graphs and also the admissible sign types of type A.
    References | Related Articles | Metrics
    Property of an orthogonal projection matrix
    DU Kun, GU Gui-ding
    2012, 2012 (1):  97-99. 
    Abstract ( 7845 )   PDF (210KB) ( 2581 )   Save
    In this paper we showed that for an orthogonal projection matrix with rank $k$, there exists an principal submatrix with order $k$ of the matrix, such that its Rayleigh quotient has a positive lower bound. The proof was made by using the relation of the singular values, eigenvalues and norm of matrices, as well as the properties of unitary matrix and compound matrix.
    References | Related Articles | Metrics
    Prolongation structure of the coupled nonlinear evolution equation
    JIA Yang-jie
    2012, 2012 (1):  100-105. 
    Abstract ( 2213 )   PDF (238KB) ( 2264 )   Save
    The coupled KdV equation proposed by is investigated in the framework of prolongation structure theory. Its Lax representation of prolongation algebra is constructed.
    References | Related Articles | Metrics
    Subspace-supercyclicity and common subspace-supercyclic vectors
    ZHAO Xian-feng, SHU Yong-lu, ZHOU Yun-hua
    2012, 2012 (1):  106-112, 120. 
    Abstract ( 2430 )   PDF (247KB) ( 2977 )   Save
    A bounded linear operator $T$ on Banach space is subspace-supercyclic for a nonzero subspace $M$ if there exists a vector whose projective orbit intersects the subspace $M$ in a relatively dense set. We constructed examples to show that subspace-supercyclic is not a strictly infinite dimensional
    phenomenon, and that some subspace-supercyclic operators are not supercyclic. We provided a subspace-supercyclicity criterion and offered two necessary and sufficient conditions for a path of bounded linear operators to have a dense $G_\delta$ set of common subspace-hypercyclic vectors and common subspace-supercyclic vectors.
    References | Related Articles | Metrics
    Oscillations of a class of third order nonlinear neutral functional differential
    HAN Zhong-yue
    2012, 2012 (1):  113-120. 
    Abstract ( 1980 )   PDF (190KB) ( 2399 )   Save
    The oscillations of a class of third order nonlinear neutral functional differential equations was discussed, by using the generalized Riccati transformation and the integral averaging technique; and some new  sufficient conditions for oscillations or tends to zero of all solutions of the equations were obtained. The
    example  to illustrate the main results were given. The results extend and improve some known results.
    References | Related Articles | Metrics
    Numerical solution of a non-arbitrage liquidity model based on uncertain volatility
    NIU Cheng-hu, ZHOU Sheng-wu
    2012, 2012 (1):  121-129, 137. 
    Abstract ( 2277 )   PDF (546KB) ( 2303 )   Save
    The option pricing model in illiquidity markets was  expanded to general situations by introducing two kinds of uncertain volatility models. As it is difficulty to get analytical solutions for the model in complicated cases, a numerical solution was discussed by establishing corresponding differential equations; and the stability and consistency of the sdution were proved. Finally, the influence of some parameters to the solution was provided in numerical examples. The results show that the algorithm reduced the restriction on step-length requirements, and satisfactory approximation can be found with less computation.
    References | Related Articles | Metrics
    One-dimensional BSDEs with monotonic, H\"{o}lder continuous and Integrable parameters
    XIAO Li-shun,LI Hui-ying,FAN Sheng-jun
    2012, 2012 (1):  130-137. 
    Abstract ( 2132 )   PDF (228KB) ( 2381 )   Save
    This paper established a new existence and uniqueness result for solutions to one-dimensional backward stochastic differential equations (BSDEs) with only integrable parameters, where the generator $g$ is monotonic in $y$ and $\alpha$-H\"{o}lder ($0<\alpha<1$) continuous in $z$. By Tanaka's formula and Girsanov's theorem we established a comparison theorem for solutions in $L^1$ to BSDEs, from which the uniqueness follows. By convolution technique we obtained a uniform approximation sequence of the generator $g$ and then constructed a sequence of solutions in $L^1$ for BSDEs. Finally, we proved the limitation of this sequence of solutions is the desired solution. This proved the existence.
    References | Related Articles | Metrics
    Singular perturbation of BVP for third-order nonlinear VDE
    LIN Su-rong, NI Ming-Kang
    2012, 2012 (1):  138-150. 
    Abstract ( 2551 )   PDF (354KB) ( 2101 )   Save
    The singularly perturbations for the vector boundary value problem of nonlinear third-order ordinary differential equations were studied. Under certain conditions, the given differential equation was transformed into a diagonalized system, and then the equivalent integral equations was solved. By using the method of succesive approximation and the theorem of fixed point, the existence of the solution of singular perturbation problem was proved and the asymptotic estimation was obtained. Finally, several examples of application were given.
    References | Related Articles | Metrics