Abstract:Under the condition that nonlinearity f(u) satisfies asymptotically linear growth at the origin and sublinear growth or suplinear growth at the infinity, the solvabitity for nonliner discrete periodic boundary value problems are discussed. By using Robinowitz global bifurcation theorem, a complete description of the global behavior of positive solution for the boundary value problem is given, and the optimal interval of a positive parameter is determined.

Abstract:We improved the theory of algorithm of genome assembly which is a generalized Lander-waterman theorem under repeat collapse. It is important for appraising the rationality of the number of contig and the quality of genome assembly.

Abstract:In this paper, a total number of 19clusters of CoNi''s alloy ground state and non-ground-state structures were studied with GEAM by using molecular dynamics method combined with simulated annealing algorithms. In this premise, some thermodynamic properties of clusters were studied by warming up the system. Through this study we found that the ground state structure of the alloy is double icosahedral structure, regardless of the proportion of the alloy, and the ground state energy increases with the rising of the number of Co atoms. In the mean time we studied the alloy clusters'' phase-change properties and found that pure metal and alloy both have pre-melting phenomenon, and the melting temperatures tend to drop with the increasing of Ni atom number when the alloy melts.

Abstract:A biosensor was fabricated with glucose oxidase (GOD) immobilized on self-assembled monolayers (SAMs)/Prussian blue (PB)/chitosan (Chit). The electrochemical characteristics of the biosensor were studied in the presence of dipolar aprotic organic solvents such as acetonitrile (AN), dimethyl sulfoxide (DMSO) and N,N-dimethyl formamide (DMF). The effect of volume percentage of organic solvents on biosensor response was investigated. It is observed that the response current of the biosensor in 50% AN reaches 73% of that in phosphate buffer solution (PBS). The amperometric signals are fast, reproducible and exhibiting high sensitivity (57.3mA·M·cm-2). The biosensor was used to determine glucose in serum specimens, and the results are consistent with those obtained with the commercially available glucose enzyme photometric kit.

Abstract:methylphenoxy)benzylamine was synthesized by the reaction of etherification and reduction with the starting materials of p-chlorobenzonitrile and p-cresol. The target compound was identified by IR and NMR. The total yield of the title compound is 69.3%, which is obtained under optimized conditions:n(NaBH₄)∶n(BF₃-Et₂O)∶n(4-(4-methylphenoxy) benzonitrile)＝1.2∶1.0∶1.0, reaction temperature of reflux condition and reaction time of 18h. The present method has the advantages of availability of starting materials, mild reaction condition, convenient manipulation, non-special equipment and good yield.

Abstract:In this paper, MDY-2electronic densitometer and Germany DCAT21automatic surface tension meter are used to measure the density and surface tension over the whole concentration range (the molar fraction of ionic liquids in oganic solvents is 0~1) for the binary mixtures of ionic liquids N-butylpyridinium nitrate (NO₃) and organic solvents such as methanol,ethanol and butanol at the temperature of 298.15K. The excess molar volumes VE and the surface tension deviations δγ of binary mixtures {NO₃₊CH₃OH},{NO₃₊C₂H₅OH} and {NO₃₊C₄H₉OH} are determined. VE and δγ are fitted by using the Redlich-Kister equation. The results show that the excess molar volumes of binary mixtures of {NO₃₊CH₃OH} and {NO₃₊C₂H₅OH} are negative over the whole composition range, while the VE of binary mixture {NO₃₊C₄H₉OH} has positive values at low molar fraction of ionic liquid, passing through a maximum and then decreases and becomes negative, showing minimum at higher ionic liquid molar fraction. The surface tension deviations δγ of 收稿日期:2012-05-04；修回日期:2012-09-05；责任编辑:张士莹 基金项目:国家自然科学基金资助项目(20776037)；河北省自然科学基金资助项目(B2012208084) 作者简介:王建英(1973- ),女,河北灵寿人,副教授,博士,主要从事离子液体方面的研究。 通讯作者:胡永琪教授。E-mail:huyq@hebust.edu.cn {NO₃₊CH₃OH} systems are positive, but those of {NO₃₊C₂H₅OH} and {NO₃₊C₄H₉OH} systems are negative over the entire molar fraction range. It seems that surface tension deviations δγ varys from positive to negative with the increase of alkyl chain length of alcohols.

Abstract:Using the inorganic zinc salt and S powder as zinc and sulfur sources separately, micrometer-sized ZnS hollow spheres were synthesized. XRD pattern indicates that as-prepared sample is cubic ZnS. The effects of reaction time, reation temperature and different zinc sources on the morphologies were studied. SEM images show that the micro-spheres with diameters ranging from 200to 300nm are self-assembled by ultra-fine particles. Flower-like ZnO nanocrystals built up by nano-flakes are successfully synthesized in the presence of surfactant CTMAB. The feasibility of the reaction is discussed thermodynamically and the formation mechanism of spherical and flower-like ZnS is proposed.

Abstract:A novel supramolecular complex [Cu₂(phon)₂(μ₂-Cl)₂Cl₂]·DMF was synthesized by situ reaction of 1,0-phenanthroline-5,6-dione with Cu(Ⅱ) salt. The complex is characterized by X-ray diffraction analysis, elemental analysis, IR and UV-visible spetra. In the dinuclear Cu(Ⅱ) complex, the Cu(Ⅱ) ion is in a distorted square pyramidal geometry(τ= 0.12) with four donor atoms (N₂Cl₂) in the basal plane and one chlorine atom occupying the apical position. In addition, hydrogen bonds (C—H…Cl and C—H…O ) and π-π intermolecular interactions link these dinuclear molecules into two-dimensional layers.

Abstract:The adsorption equilibrium and kinetic of methylene blue dye on bambo carbon(BC) were examined at room temperature,and the effect of the original concentration of methylene blue and the amount of bamboo carbon were measured. Adsorption isotherm of the methylene blue (MB) on the bamboo carbon was determined and correlated with Langmuir and Freundlich adsorption isotherm equations. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. The result shows that the equilibrium data for methylene blue adsorption fit to the Freundlich equation(R²=0.99) well. The adsorption of methylene blue could be best described by the pseudo-second-order equation. The kinetic parameters of this best-fit model were calculated and discussed.

Abstract:Based on the brief introduction of the operation principle and superior performance of PM deflection type three-degrees-of-freedom motors in this paper, the new PM motor air-gap magnetic field calculation schemes have been presented and the scalar magnetic flux density calculation formula in the spherical coordinate are established. The rotor magnetic field model is built in 3D finite element software and computed with simulation to derive the flux density distribution under different magnetization modes. The results by these two methods are compared and validated. The theoretical analysis and computation results demonstrate the effectiveness of the designed structure; the rotor is easy to achieve three-degrees-of-freedom deflection motion, which can provide references for further research and experimental design.

Abstract:This paper presents a novel fault detection and identification (FDI) method for a class of nonlinear systems. An introduction of the ESO theory is given, and based on this theory a novel fault diagnosis filter is constructed for diagnosis of nonlinear system fault. Simulation examples illustrate the effectiveness and the outstanding feature of the method that it can detect and identify the shape and magnitude of system fault simultaneously.

Abstract:A method of examining paper format based on image segmentation was proposed. According to the relevance of pixels in the image of electronic paper, paper image was segmented into title, text and pictures by using Markov-Chain model. And every paper image can be examined in accordance with segmentation followed by manually setting the paper format rules. The test results indicate that it is helpful to improve the efficiency of examining paper format.

Abstract:Compared with coal-fired power generation, steam pressure of waste heat power generation has the characteristic of mutation. Now the domestic waste heat generator excitation uses constant power factor regulating mode after connected with power grid. When steam pressure of steam turbine mutates, due to that active power mutation at the same direction, the generator power-angle will change at the same direction too. When power-angle is more than the allowable value, generator may be out-of-step parking. Three closed loop excitation control devices based on DSP is developed to solve this problem. When the steam pressure is greater than the maximum value, generator works at constant power angle. When the steam pressure is less than maximum value, generator works at constant power factor mode. Before connected with power grid, generator works at constant exciting current mode, so that the generator is always energy-saving and in reliable operation.

Abstract:This paper describes the implementation of Booth algorithm in a 8-bit microprogram controlled model computer.Through analyzing the Booth algorithm by using the flow chart and program assembly language, it is found that the Booth algorithm can be applied to 8-bit microprogram controlled model computer.

Abstract:Considering the difficulty of accurately and fast location of ROI of inner-knuckle-print, a new location algorithm is presented forward based on dimension reduction. This algorithm transforms 2-dimension image data to two 1-dimension data by projecting the binary image in vertical and horizontal direction, and then aligns ROI images through the comparison of the two 1-dimension data.This leads to rapid and efficient recognition. The experimental results verify that it is rapid and effective than traditional methods.

Abstract:By using the solidification/melting model of FLUENT software, the melting and solidification process of the aluminum-silicon alloy in a cylinder heat storage with double wall were simulated numerically. Considering the third kind of boundary condition, the dynamic temperature field distribution and the position of the phase interface change moving with time are obtained. And the melting and solidification duration time is also calculated. The results have important reference value for the numerical simulation of the phase change problem and the design of phase change energy storage device.

Abstract:The degradation of Poly(3HB-co-4HB) by pseudomonas mendocina DS04-T was studied. Poly(3HB-co-4HB) was used as the sole carbon source of culture medium. The influence of cultivation time, cultivation temperature, shaking revolution, liquid medium volume, initial pH and inoculation content were studied. Combining single factor test and orthogonal test, the optimal degrading enzyme production conditions were chosen as follows:cultivation time is 28h, cultivation temperature is 30℃, shaking revolution is 150r/min, initial pH is 7.3, culture medium volume is 120mL and inoculation content is 1.5%(V/V). Under the optimized condition, the degradation enzyme activity reaches(26.2±0.7) U·mL-1.

Abstract:Unique multi-channel flow path is designed and peristaltic pumps are used. Supplemented by automatic control system, the digestion, color, measurement and data processing are separately completed and the total phosphorus and total nitrogen of seawater are automatically measured. The detection limits are 0.00174mg/L (TP) and 0.00375mg/L (TN). The relative standard deviations are 7.06% (TP) and 2.17% (TN).The detection extraction recoveries are 98.1% (TP) and 92%(TN).

Abstract:Microbubble aeration is a new type of bubble aeration, and contaminants in waste water has great influence on oxygen transfer in microbubble aeration. The effects of different typical contaminants on oxygen transfer in microbubble aeration were investigated by using a gas-water circulation type microbubble generator, including surfactants, soybean oil, phenol and nitrobenzene as well as suspended solid (kaolin). The results indicate that different from traditional bubble aeration, microbubble aeration seems like milk-turbid due to very small bubble size. The soluble organic contaminants improve generation and stability of microbubbles, resulting in higher gas holdup and gas retention time. The range of oxygen transfer coefficient KLa is 7.44~11.56h-1, and the range of α-factors is 0.77~1.20in microbubble aeration with the typical contaminants under all test conditions, larger than those in traditional bubble aeration. The improvement of microbubble generation and stability in presence of the contaminants should be responsible for the reduction of negative effect of contaminants on oxygen transfer. The gas hold-up and contaminant type are the important influencing factors for oxygen transfer in microbubble aeration.

Abstract:The cross shaped columns nodes are weak for its own causes, hindering the development of special-shaped column structure system. With a residential project in Tianjin as the background, combining the seismic performance test of steel fiber reinforced a cross shaped column, the design requirements and the construction procedures, economic analysis of the steel fiber reinforced nodes are provided.