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1.
Thermodynamic Optimization of DyCl3 -NaCl System   总被引:2,自引:0,他引:2  
In this paper, the phase diagram of the DyCl3 -NaCl system is optimized and calculated with CALPHAD ( calculation of phase diagram ) technology. A set of thermodynamic functions of compounds Na3 DyCl6, NaDyCl4, and NaDY2 Cl7 have been optimized and calculated based on an interactive computer-assisted analysis. The optimized thermodynamic parameters, calculated phase diagram and experimental phase diagram are thermodynamically serf-consistent.  相似文献   

2.
Toda链的新解     
The bilinear Baecklund transformation (BT) provides a means of finding multisoliton solutions of some non-linear evolution equations, where Hirota‘s technique is used. In this paper, the bilinear BT for Toda lattice was modified and then some novel solutions of the Toda lattice was constructed through the modified BT.  相似文献   

3.
High frequency ultrasonic nondestructive testing was conducted using a direct contact method for SUS306 stainless steel treated by high temperature and fracture tensile tests. Reflected ultrasonic echoes were analyzed. The relationships between the ultrasonic attenuation coefficient, strength of backscattering wave and the elongation at break of the samples were obtained. The damages were evaluated by using these results together with the analysis of microstructure and mechanics of the tested material. Project supported by the National Natural Science Foundation of China (Grant No.60472102), and the Innovative Program of Shanghai Municipal Education Commission (Grant No.07ZZ03)  相似文献   

4.
This paper proposes a global stabilization method for a class of planar switched systems with input saturation constrains by using a state feedback and switching strategy. This method is proved to be effective by analyzing the characteristics of the trajectory of second-order linear systems with input saturation. Project supported by the China Postdoctoral Science Foundation (Grant No.20070420643), the National Natural Science Foundation of China (Grant No.60774059), and the Innovation Program of the Shanghai Municipal Science and Technology Commission (Grant No.08DZ2272400)  相似文献   

5.
n-soliton-like solutions of three non-isospectral equations, the non-isospectral mKdV equation, the non-isospectral sine-Gordon equation and the non-isospeetral nonlinear Schroedinger equation were obtained by using the Hirota method.  相似文献   

6.
The effect of rare earth (RE) elements on the morphologies and sizes of Si phases in the hypereutectic Al-Si alloys modified with P was investigated.The results show that the addition of La element to the hypereutectic Al-Si alloys can enhance the effect of P element on the modification of the primary Si phases.In the multiplex modification of RE-P,the primary Si phase is refiner and the shape of the eutectic Si is changed from long needle-like to short rod-like.Moreover,the agglomeration rate of the primary Si phase is slowed greatly.Even the melt is held for 6 h,the average size of the primary Si phase is still satisfied.The results analyzed by scanning electron microscope (SEM) indicate that La is richer at A1-Si interface than that inα-Al or primary Si phase.The higher the La content in the Al-Si interface,the smaller the primary Si phase.  相似文献   

7.
The reaction of ZnO nanoparticles grafted with KH570 silane coupling agent was carried out in water-alcohol mixed solvent. Several characterization methods were applied to analyzing the results of surface modification such as Soxhlet extraction, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and zeta potential (ζ). The results of FT-IR and TG-DSC show that the desired reaction chains have been covalently bonded on the surface of ZnO nanoparticles. Zetasizer results reveal that themaximal absolute value of ζ of the modified ZnO particles in acetone medium was 67.0 mV, which was much higher than that of the unmodified ZnO particles. So the surface of nanosized ZnO changed from hydrophilicity to hydrophobicity and the dispersity of ZnO nanoparticles were improved simultaneously. Finally, the mechanism of graft modification was discussed.  相似文献   

8.
关于混沌洛伦兹系统和陈系统中的广义投影同步   总被引:1,自引:1,他引:1  
1 Introduction Since Pecora and Carroll[1]showed that it is possibleto synchronize two identical chaotic systems , chaossynchronization has been intensively and extensivelystudied due to its potential applications in secure com-munication,ecological systems ,systemidentification,etc.(see [2] and a huge volume of references citedtherein) . Among all kinds of chaos synchronizations ,projec-tive synchronization is one of the most noticeableones .This kind of synchronization was first observedin …  相似文献   

9.
In this note, we prove that the convergence rate of the modified Gauss-Seidel (MGS) method with preconditional I Sa isa monotonic function of preconditioning parameter a. Based on this result, to achieve better convergence rate we suggest proformingtwice preconditoning when applying the MGS method to solve a linear system whose coefficient matrix is an irreducible non-singularM-matrix.  相似文献   

10.
For the non-conservative holonomic Hamiltonian systems in phase space, the definition and criteria of the form invariance of the generalized Hamilton canonical equations were given. The relations among the form invariance, Noether symmetry and Lie symmetry were studied. The theory of the form invariance for the conservative holonomical systems was worked out. An example was given to illustrate the results.  相似文献   

11.
A novel asymmetrical pitch system for rotary wing is presented. The pitch control characteristics are studied and analyzed. Because elastic linkage is a key part in whole asymmetrical pitch system, in order to obtain the variation of the elastic linkage deformation, an experimental platform mainly based on the device of micro aerial vehicles (MAVs) and a new control system mounted on TMS320LF2407 are designed. This control system has its compacted configuration and reliability. Finally, using this system to control the MAV for simulating the flying forward, experimental results show the MAV’s flight attitude can be controlled based on the variation of the elastic linkage. Project supported by the National Natural Science Foundation of China (Grant No.60605028), the National High-Technology Research and Development Program of China (Grant No.2007AA04Z225), the Shanghai Rising-Star Program (Grant Nos.07QA14024, 07QH14006), the Shanghai Shuguang Program (Grant No.07SG47), and the Shanghai Leading Key Laboratory of Mechanical Automation and Robotics Science Foundation (Grant No.ZZ0805)  相似文献   

12.
Two types of molecular and polymer devices employing (2-(4′-biphenyl)-5-(4““““““““-tert-butylphenyl)-1,3,4-oxadiazole) (PBD)and poly(N-vinylcarbazole) (PVK) as electron transport and hole transport materials, respectively, have been fabricated. The structures of these two devices are ITO/PVK( 70 nm)/PBD(60 nm)/A1 and ITO/PVK: PBD (1:1 by mass, 70 nm)/A1. The formation of exciplex is evident by comparing the electroluminescence (EL) of a bi-layer device and the photoluminescence (PL) of a PVK and PBD mixed film.The maximum emission energy of exciplex evaluated is consistent with the peak emission of EL. Blue emissions from both devices are obtained. The type of exicplex is interpreted based on the energy level diagram of the bi-layer device.  相似文献   

13.
This paper introduces a formula for the vertical pressure on a buried pipeline by using a modification of the basic assumptions of Marston’s theory. The fill’s cohesion is considered. The included angle between the slide surface above the pipeline and the horizontal surface is assumed to be equal to the fill’s angle of friction. The friction is calculated by multiplying the active earth pressure on the outer column and the coefficient of the friction on the slide planes It was found that the fill’s cohesion had important influence on the vertical pressure, whose vertical pressureC c decreases with increase of the fill depth, a relationship according with that observed in practice. At the end of the paper, the formula is employed to analyze a practical case. Project (No. RC9609) supported by Natural Science Foundation of China (NSFC)  相似文献   

14.
In this paper, we discuss a class of piecewise linear hyperbolic maps on the 2-torus. These maps arise in the second-order digital fdter with two' s complement arithmetic. By introducing codings underlying the map operations, we give some admissibility conditions for symbolic sequences and find some periodic properties of these symbolic sequences. Then we use these conditions to check the admissibility of periodic symbol sequences.  相似文献   

15.
The choice of self-concordant functions is the key to efficient algorithms for linear and quadratic convex optimizations, which provide a method with polynomial-time iterations to solve linear and quadratic convex optimization problems. The parameters of a self-concordant barrier function can be used to compute the complexity bound of the proposed algorithm. In this paper, it is proved that the finite barrier function is a local self-concordant barrier function. By deriving the local values of parameters of this barrier function, the desired complexity bound of an interior-point algorithm based on this local self-concordant function for linear optimization problem is obtained. The bound matches the best known bound for small-update methods. Project supported by the National Natural Science Foundation of China (Grant No.10771133), the Shanghai Leading Academic Discipline Project (Grant No.S30101), and the Research Foundation for the Doctoral Program of Higher Education (Grant No.200802800010)  相似文献   

16.
Batch processes have been increasingly used in the production of low volume and high value added products. Consequently, optimization control in batch processes is crucial in order to derive the maximum benefit. In this paper, a run-to-run product quality control based on iterative learning optimization control is developed. Moreover, a rigorous theorem is proposed and proven in this paper, which states that the tracking error under the optimal iterative learning control (ILC) law can converge to zero. In this paper, a typical nonlinear batch continuous stirred tank reactor (CSTR) is considered, and the results show that the performance of trajectory tracking is gradually improved by the ILC. Project supported by the Science Foundation of Shanghai Municipal Education Commission (Grant No.09Y208), and the Science Foundation of Science and Technology Commission of Shanghai Municipality (Grant Nos.08DZ2272400, 09DZ2273400) and the “11th Five-Year Plan” 211 Construction Project of Shanghai University  相似文献   

17.
In this paper, dynamics in the oscillations of the relative atomic population in two periodically driven and weakly coupled Bose-Einstein eondensates (BECs) was qualitatively studied. Using the well-known Melnikov method, the conditions of existence of the periodic and chaotic coherent atomic tunnellings were given in the model. Our results indicate the typical route from bifurcation of the limited circles to chaos, and are in agreement with the previous numerical results.  相似文献   

18.
Reaction thrust of water jet for conical nozzles   总被引:1,自引:0,他引:1  
Clear knowledge on the reaction thrust of water jet is valuable for better design of water jet propulsion system. In
this paper, theoretical, numerical and experimental studies were carried out to investigate the effects of the nozzle geometry
as well as the inlet conditions on the reaction thrust of water jet. Comparison analyses reveal that the reaction thrust has a
direct proportional relationship with the product of the inlet pressure, the square of flow rate and two-thirds power exponent
of the input power. The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence
on the reaction thrust characteristics. In addition, the best values of the half cone angle and the cylinder column length exist
to make the reaction thrust reach its maximum under the same inlet conditions.  相似文献   

19.
In the present paper, the formulae for matrix Padé-type approximation were improved. The mixed model reduction method of matrix Padé-type-Routh for the multivariable linear systems was presented. A well-known example was given to illustrate that the mixed method is efficient. Project supported by National Natural Science Foundation of China (Grant No. 10271074)  相似文献   

20.
The surface morphology and growth mechanism of an aluminum film system deposited on silicone oil surfaces by a vapor depositing method was investigated by scanning electron microscopy. It was found that the perpendicular fluctuation of the film's bottom surface was more remarkable than that of the film's top surface. Near the joint between the film on the silicone oil substrate and the film on the silicon wafer surface on which the silicone oil substrate rested, was a naturally formed anomalous wedge-shaped wrinkly structure with slopes of 10−4–10−5 rad, whose growth mechanism could be interpreted under the assumption of the thermal expansion behavior of the liquid substrates. Project supported by NSFC (No. 19874016) and the Special Fund of Zhejiang Provincial Natural Science Foundation for Young Scientists (Grant No. 1997RC9603).  相似文献   

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