Abstract:In this paper, a new fixed point theorem and the properties of Green function are used for the nonlocal boundary value problems. The existence of at least one positive solution to the nonlocal fourth-order boundary value problem with the first order derivative u(4)(t)+Au″(t)=λf(t,u(t),u′(t)),0＜t＜1,u(0)=u(1)=∫¹_0p(s)u(s)ds,u″(0)=u″(1)=∫¹_0q(s)u″(s)ds is considered, where f is a nonnegative continuous function and λ＞0,0＜A＜π²,p,q∈L[0,1],p(s)≥0,q(s)≥0. Finally, a simple example is presented to illustrate the correctness of the obtained results.

Abstract:A graph G is called (k,d)* -choosable if, for every list assignment L satisfying |L(v)|=k for all v∈V(G), there is an L-coloring of G such that each vertex of G has at most d neighbors colored with the same color as itself. Zhao and He first studied the (3,1)*-list coloring of the 2-connected planar graphs just by using Euler''s formula and the graph''s structural properties. The paper continues to investigate the use of Euler''s formula in (3,1)*-list coloring the planar graphs, and shows that Euler''s formula is also practicable in dealing with the planar graphs containing cut vertices.

Abstract:By using cone and partial ordering theory and the skill of monotone iteration, the existence and uniqueness of the solution to α-t type bump reverse mixed monotone operator equations is established, which do not contain any continuity and compactness conditions. The results generalize some known results of mixed monotone operators.

Abstract:The well-posed probem of the full Ericksen-Leslie system for nematic liquid crystal is analyzed, and the existence and uniqueness of the local strong solutions to the incompressible liquid crystal equations is obtained by using fixed point theorem when the initial values fit the regular conditions.

Abstract:Two kinds of imidazole ionic liquids(PF_6and BF₄) are synthesized from N-methyl-midazolium, chlorobutane, KPF_6and NaBF_4under microwave irradiation and water bath heating respectively by two-step method. The advantage and disadvantage in the synthesis of intermediate and anion exchange are compared, and the structure characteristics and electrochemical performance are characterized. The result shows that the ionic liquids synthesized by two different methods have no evident discrepancy. The reaction time can be cut down markedly under the microwave, and the productivity can exceed 90%, while the water bath heating is propitious to anion exchange. So combining the two methods will get a favorable result.

Abstract:With maleic anhydride as raw material, hydrogen peroxide as oxidan, and sodium tungstate as catalyst, the intermediate epoxy succinic acid(ESA) is synthesized. Then, with epoxy succinate (ESA), acrylic acid (AA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) as raw materials, and ammonium persulfate as initiator, a new type of green scale inhibitor ESA/AA/AMPS copolymer is synthesized. The overall inhibiting performence and the capacity of stabilizing zinc are evaluated by the static scale method. The test results show that ESA/AA/AMPS copolymer''s inhibiting ability for calcium carbonate scale is roughly equal to PESA, and its ability in resisting calcium phosphate scale, calcium sulfate scale and the capacity of stabling zinc are significantly better than PESA.

Abstract:The permittivity of carbon fibers in different composites is calculated and discussed by using M-G equations, Bruggeman equations and generalized M-G equation. Results show that for high draw ratio fibers, all the three equations can calculate out the permittivity with the same numerical level and variation trend. Generalized M-G equation and M-G equation have a similar result but Bruggeman''s result is smaller. All three equations become invalidation when fibers'' concentration reaches its percolation threshold, which means that all three equations are useful at low concentration.

Abstract:Aiming at cascading overload phenomenon in power network and considering structural integrity, the fluctuation phenomenon is researched into. Firstly, according to the thoughts that a power network is often weakened by cascading failure of branches, a statistical fluctuation model which can represent the structural integrity of a power network is proposed. Then an example in IEEE 39-bus system with continuously increasing of the injection power of nodes is given. The analysis results show that the fluctuation value of the relative parameter increases with the increase of the total load of the power system, and a critical point exists in that course. At last, in order to further prove that regulation, another example with IEEE 14-bus is analyzed.

Abstract:In order to study the correlation of the electromagnetic radiation susceptibility tests in a reverberation chamber and an OATS, the physical model of a reverberation chamber and an OATS is established separately by using the electromagnetic simulation software FEKO. Six frequencies (200,0, 500,0, 800,0MHz) are chosen in the common work frequency band (range of 170MHz to 1GHz) of the reverberation chamber and the OATS. At each frequency the induced currents in the small electrical monopole antennas in the reverberation chamber and the OATS are calculated. The electric field strength in the relevant position is also calculated. The data are statistically analyzed. It is concluded that the correlation of the normalized induced currents in the monopoles is very good.

Abstract:This article proposed a new design of a chip benchmark power sourse, which is a very important component of mixed signal IC and RF integrated circuit. To meet the requirement of low voltage and large-scale integrated CMOS circuit of high-precision, the use of reference source is rigors for A/D and D/A converter, high sensitive RF circuits and so on. Most parts of the benchmark source employ benchmark bandgap voltage source on chip, so a low power consumption, low temperature coefficient and high performance low pressure CMOS bandgap benchmark voltage source with higher PSRR is designed. It uses one level temperature compensation, current feedback technology, offset circuit temperature compensation technology and RC phase margin compensation technology. This circuit adopts the 0.18um process of TSMC, and uses the Specture to simulate. The simulation result verifies the feasibility and rationality of the design.The circuit can be uesd for low voltage and low power consumption with higher PSRR.

Abstract:Electromagnetic scattering characteristics of the microstrip antenna array is analyzed by using the adaptively modified characteristic basis function method (AMCBFM). Volume electric field integral equation and SWG basis function are applied to the material region, while the surface electric field integral equation and RWG basis function are applied on the conducting surface of the microstrip antenna array. The method of moments (MoM) is used to convert the integral equation into a matrix equation. The bistatic RCS of 7×7microstrip antenna array and the monostatic RCS of 2×2microstrip antenna array are analyzed numerically. The results indicate that the proposed method has a series of merits:reducing the size of the matrix equation into a small level and saving the memory requirments.

Abstract:A blind digital image watermarking algorithm based on DCT is put forward. The watermarking image is embedded in the load image through adjusting the magnitude relationship of the chosen medium frequency coefficient, which is easy. Experiments prove the strong ability of proposed algorithmin resisting shear attracts, noise attracts, compression attracts, and other common attracts.

Abstract:This paper presents a random seed nearest neighbour search clustering algorithm (RS-NNS). The method is to follow the nearest neighbours'' direction of a random selected seed, search and find its neighbours which have the greatest similar features, form the local maximum cluster, adjust dynamically the data objects'' belongingness to realize the local optimization, and end the clustering procedure until all the data objects are identified. Experiments verify that the new algorithm fits the problems such as different density, shape, noise, cluster number and so on, and can realize fast optimization searching.

Abstract:Data flow diagram is an important tool in the development of information system to link developers with users. But there is no uniform standard as to how to draw the flow chart of data. This paper puts forward 8important principles to draw good data flow diagram. In accordance with these principles, the data flow diagram can be easily drawn.

Abstract:When making use of AutoLISP of AutoCAD to develop the CAD system of the worm hob, the functions provided by AutoLISP can''t fulfill all requirements in the design process of the worm hob. So some complementary functions such as calculating, dimensioning and drawing are developed to make an unattached module. It can be transferred by every module of the system. Through running the system, the necessity and the validity of the database are verified.

Abstract:By using the piecewise continuum technique, a continuous computational model is developed for second-order analysis of variable cross-section frame-shear wall structure. By introducing the concept of state vectors, the state space equations of every segment in second-order analysis are derived, then the state vector expression can be calculated according to the state space theory, and the initial state vector can be obtained according to the boundary conditions of the structure by using the precise integration method. The displacements and internal forces of each member can be derived as well. The numerical example is shown and the result is compared with that of other methods.

Abstract:In order to determine the most reasonable height of flat vierendeel structure, the stiffness characteristics of flat vierendeel structure are analyzed. Firstly, the conclusion is drawn by analytical method that there is a most reasonable height for any flat vierendeel structure. Secondly, the influence of some main parameters is studied. At last, the calculation formula for the most reasonable height is deduced. Different cases are studied by FEM, and the results confirm the above conclusions and the validity of the formula.

Abstract:The research has demonstrated that the stress and strain distribution on the surface of the ST12welded I-section steel bracing members gained by numerical analysis is in accordance with the true distribution. In this paper, three critical plane damage models, established based on the relationship between the strain and the low cycle fatigue life, are used to simulate the damage and predict the low cycle fatigue lives of the ST12welded I-section bracings. The results show that, the location of the crack initiation can be predicted accurately, and the predicted lives are all less than the test ones. The empirical formulas are regressed and compared with the empirical formula obtained by the test results. It is verified that the main factors affecting the low cycle fatigue life are the flange width-thickness ratio b/t and the slenderness λ. Under the premise of meeting the design requirement of "no buckling under frequent earthquake" and the allowable range of standards, it is suggested that small b/t and large λ should be adopted in the brace design.

Abstract:The catalyst for formic acid decomposition is prepared by co-precipitation method. The influence of various operation condition on catalyst activity is discussed, including precipitation, aging, auxiliary and calcination. The results of the experiment show that when multiple Ni/NiO/ZnO catalyst, which is prepared with alcohol-water solution as solvent, nickel-zinc molar ratio of 1∶1.5(mol), citric acid as the auxiliary, precipitation temperature of 60℃, aging for 4h and calcined for 4h at 500℃ in N₂, is used for formic acid decomposition in low concentration of formic acid-DMF solution, the decomposition rate is up to 95.34%.The characteristic results by XRD show that the prepared catalyst is Ni/NiO/ZnO multiple catalyst with average size of 40nm. The catalyst can be used for formic acid decomposition in recycing DMF from leather wastewater.

Abstract:Based on Microsoft Visual C++6.0, software of online automatic monitoring system for total phosphorus and total nitrogen in seawater is developed, including the controlling interface of the on-line monitoring system, the driving programs of device, the processing and display of experimental data and the query of historical monitoring data. The software mainly consists of five parts of design process module, manual experiment module, real-time monitoring module, parameter configuration module and serial communication module. Windows graphical interfaces and option card technologies are adopted in the software system, so that this system has friendly visualized man-machine interface and stable operation, and it meets the requirements of experiments.

Abstract:Based on the statistics of running condition of field equipment and the fuzzy information provided by experts, the fault tree of fire accident in cotton plant is constructed. A reliability analysis on fire accident is made by using sharp-state-typed membership function of the fuzzy fault tree theory, then the fuzzy probability distribution of the explosion is gained.The structural importance of each basic event is also analyzed, and the most influencing factors are determined. It provides a new way for safety analysis of the system and prevention of fire accidents.