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The electronic properties of curium trichloride (CmCl3) are studied using single-particle approximations and a many-body approach in this work. The imaginary parts of the Matsubara Green’s functions suggest that 5fj=5/2and 5fj=7/2manifolds are both in the conducting states, together with the very weak Cm 5f-conduction electron hybridization and localized 5f-derived spectra feature near the Fermi level. The ratio of the quasi-particle weights R= Zj=7/2/Zj=5/2is larger than 1.0, implying that CmCl3is in the orbital-selective localized state. The intermediate coupling (IC) mechanism is suitable for the angular momentum coupling of Cm 5f electrons. The admixing of 5f7and 5f8configurations would give rise to the interconfiguration fluctuation (5f7.365) and the mixed-valence state (Cm2.635+) of Cm ions, which could account for the configuration-mixing-driven quasiparticle multiplets in CmCl3. The 5fn-mixing-driven interconfiguration fluctuation might be due to the quantum mechanics processes such as the coexistence of the localized and itinerant 5f electrons and the flexible electronic configuration of Cm ions. Finally, the so-called quasiparticle band structure is also predicted.

Based on piecewise cubic interpolation polynomials, we develop a high-order numerical method with nonuniform meshes for nonlinear fractional ordinary differential equations (FODEs) with weakly singular solutions. This method is a fractional variant of the classical Adams-type implicit–explicit method widely used for integer order ordinary differential equations. We rigorously prove that the method is unconditionally convergent under the local Lipschitz condition of the nonlinear function, and when the mesh parameter is properly selected, it can achieve optimal fourth-order convergence for weakly singular solutions. We also prove the stability of the method, and discuss the applicability of the method to multi-term nonlinear FODEs and systems of multi-order nonlinear FODEs with weakly singular solutions. Numerical results are given to confirm the theoretical convergence results. [ABSTRACT FROM AUTHOR]

A second-order accurate Crank–Nicolson finite difference method on uniform meshes is proposed and analyzed for a class of nonlinear partial integro-differential equations with weakly singular kernels. The first-order time derivative is approximated by using a Crank–Nicolson time-stepping technique, and the singular integral term is treated by a product averaged integration rule, which preserves the positive semi-definite property of the singular integral operator. In order to obtain a fully discrete method, the standard central finite difference approximation is used to discretize the second-order spatial derivative, and a suitable second-order discretization is adopted for the nonlinear convection term. The solvability, stability and convergence of the method are rigorously proved by the discrete energy method, the positive semi-definite property of the associated quadratic form of the method and a perturbation technique. The error estimation shows that the method has the optimal second-order convergence in time and space for non-smooth solutions. Newton's iterative method and its algorithm implementation are presented to solve the resulting nonlinear system. Numerical results confirm the theoretical convergence result and show the effectiveness of the method. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to discuss the stagnation-point flow and heat transfer for power-law fluid pass through a stretching surface with heat generation effect. Unlike the previous considerations about the research on stagnation-point flow, the process of heat transfer and the convective heat transfer boundary condition use the modified Fourier's law in which the heat flux is power-law-dependent on velocity gradient. Design/methodology/approach: The similarly transformation is used to convert the governing partial differential equations into a series of ordinary differential equations which are solved analytically by using the differential transform method and the base function method. Findings: The variations of the velocity and temperature fields for different specific related parameters are graphically discussed and analyzed. There is a special phenomenon that all the velocity profiles converge from the initial value of velocity to stagnation parameter values. And the larger power-law index enhancesthe momentum diffusion. A significant phenomenon can be observed that the larger power-law index causes a decline in the heat flux. This influence indicates that the higher viscosity restricts the heat transfer. Furthermore, both velocity gradient and temperature gradient play an indispensable role in the processes of heat transfer. Originality/value: This paper researches the process of heat transfer of stagnation-point flow ofpower-law magneto-hydro-dynamical fluid over a stretching surface with modified convective heat transfer boundary condition. [ABSTRACT FROM AUTHOR]

A high-order compact finite difference method on nonuniform time meshes is proposed for solving a class of variable coefficient reaction–subdiffusion problems. The solution of such a problem in general has a typical weak singularity at the initial time. Alikhanov’s high-order approximation on a uniform time mesh for the Caputo time fractional derivative is generalised to a class of nonuniform time meshes, and a fourth-order compact finite difference scheme is used for approximating the spatial variable coefficient differential operator. A full theoretical analysis of the stability and convergence of the method is given for the general case of the variable coefficients by developing an analysis technique different from the one for the constant coefficient problem. Taking the weak initial singularity of the solution into account, a sharp error estimate in the discrete L2-norm is obtained. It is shown that the proposed method attains the temporal optimal second-order convergence provided a proper mesh parameter is employed. Numerical results demonstrate the sharpness of the theoretical error analysis result.

We propose a new compact alternating direction implicit (ADI) finite difference scheme on uniform meshes for a weakly singular integro-differential equation in three space dimensions. Compared with the compact non-ADI scheme, the proposed compact ADI scheme is easy to implement and significantly reduces the computational cost of solving the resulting linear system, while maintaining the same order of the local truncation error. We prove that the new compact ADI scheme is unconditionally stable, and has second-order convergence in time and fourth-order convergence in space for weakly singular solutions. Numerical results are given to confirm the theoretical analysis result and demonstrate the computational efficiency of the proposed compact ADI scheme.

This paper is concerned with numerical methods for a class of nonhomogeneous Neumann problems of time-fractional reaction–diffusion equations with variable coefficients. The solutions of this kind of problems often have weak singularity at the initial time. This makes the existing numerical methods with uniform time mesh often lose accuracy. In this paper, we propose and analyze a high-order compact finite difference method with nonuniform time mesh. The time-fractional derivative is approximated by Alikhanov's high-order approximation on a class of fitted time meshes. For the spatial variable coefficient differential operator, a new fourth-order boundary discretization is developed under the nonhomogeneous Neumann boundary condition, and then a new fourth-order compact finite difference approximation on a space uniform mesh is obtained. Under the assumption of the weak initial singularity of solution, we prove that for the general case of the variable coefficients, the proposed method is unconditionally stable and the numerical solution converges to the solution of the problem under consideration. The convergence result also gives an optimal error estimate of the numerical solution in the discrete L 2 -norm, which shows that the method has the spatial fourth-order convergence, while it attains the temporal optimal second-order convergence provided a proper mesh grading parameter is employed. Numerical results that confirm the sharpness of the error analysis are presented. [ABSTRACT FROM AUTHOR]

In this paper, the nature and origin of single event effects (SEE) are studied by injecting laser pulses into different circuit blocks, combining with analysis to map pulse width modulators circuitry in the microchip die. A time-domain error-identification method is used in the temporal characteristic analysis of SEE. SEE signatures of different injection times are compared. More serious SEE are observed when the laser shot occurs on a rising edge of the device output for blocks of the error amplifier, current sense comparator, and T and SR latches.

We propose a fractional Adams–Simpson-type method for nonlinear fractional ordinary differential equations with fractional order α∈(0,1). In our method, a nonuniform mesh is used so that the optimal convergence order can be recovered for non-smooth data. By developing a modified fractional Grönwall inequality, we prove that the method is unconditionally convergent under the local Lipschitz condition of the nonlinear term, and show that with a proper mesh parameter, the method can achieve the optimal convergence order 3+αeven if the given data is not smooth. Under very mild conditions, the nonlinear stability of the method is analyzed by using a perturbation technique. The extensions of the method to multi-term nonlinear fractional ordinary differential equations and multi-order nonlinear fractional ordinary differential systems are also discussed. Numerical results confirm the theoretical analysis results and demonstrate the effectiveness of the method for non-smooth data.

Experiment disodium phenyl phosphate as a reaction basic, stromal hydrolysis produce phenol, the amount of phenol indirectly indicates the activity of Alkaline Phosphatase.Experiment by absorption wavelength, activated sludge volume, disodium phenyl phosphate, aluminum sulfate, reagent, temperature and other factors affecting the determination of Alkaline Phosphatase were studied.The experiments optimal reaction conditions initially identified. At 37°C, when activated sludge volume of 5mL, 15mL disodium phenyl phosphate absorbance measured at the maximum value, highest levels of Alkaline Phosphatase. Results show that, 0.25mL reagent optimum dosage for the trial, the best absorption wavelength through fitting the peak-valley is 590nm.

The structure-based pharmacophore (SBP) model is consisted by the complementarity of the chemical features and space of the interaction between the ligand and receptor. The SBP models always have a high specificity which can only represent the specific class of the ligand. To simplify the models, sub-pharmacophore was then proposed in present study, and was expected to have and only have the most important or the common chemical features which play the major role in the interaction of ligand and receptor. Sub-pharmacophore should contain 4-6 features, the higher specificity with more features, and vice versa. The sub-pharmacophore was generated by the random combination of features from the structure-based models. With the MDL Drug Data Report database used as the testing database, a new metric CAI (comprehensive appraisal index), which integrated the metrics of E and A%, was defined and used to determine the best sub-pharmacophore model. C-Jun N-terminal kinase (JNKs) is one of the mitogen-activated protein kinase family, and widely involved in immune response and inflammatory response, and other pathological processes. JNK3 is mainly distributed in the brain and nervous system. In present study, twenty-five initial SBP models of JNK3 inhibitors were directly constructed from the Protein Data Bank (PDB) complexes by the LigandScout software. Then, 1018 sub-pharmacophore models were obtained from the 25 initial models. Finally, the best sub-pharmacophore was determined which was simplified from the initial model generated from the 3FI2 complex, and included four features: one hydrogen bond donor, one hydrogen bond acceptor, and two hydrophobic groups. The metrics of E, A% and CAI value of the best sub-pharmacophore model are 17.47, 31.15 and 5.44, respectively. The potential JNK3 inhibitors were then identified from Chinese herbs with the best sub-pharmacophore model, and 286 compounds were obtained.

Ten structure-based pharmacophore models of Cyclooxygenase 2 (COX-2) inhibitors were generated by LigandScout based on COX-2 inhibitor complexes from the Protein Data Bank (PDB). The potential COX-2 inhibitors were identified from traditional Chinese medicine with the method of combinatorial screening with ten models. Based on the screening results of MDDR and the metrics of E, A% and comprehensive appraisal index (CAI), the threshold of hit frequency of molecules was defined and used to identify the active molecules from Chinese herbs. The molecules hit by not less than six pharmacophore models were taken as the screening objects of COX-2 inhibitor, and 1103 molecules were obtained.

Multiple targets which closely related to Alzheimer's disease (AD) pathogenesis were selected for pharmacophore models generation and virtual screening in Chinese herbs. The targets comprised Acetylcholinesterase (AchE), muscarinic receptor 1 (M1), γ-secretase and glycogen synthase kinase 3β (GSK-3β). The pharmacophore models, which of AchE inhibitors, M1 agonists, γ-secretase inhibitors and GSK-3β inhibitors, were constructed by distance comparison method. Four testing databases for the evaluation of pharmacophore models were constructed with the active compounds with clearly marked activity on each target. The metric CAI (Comprehensive Appraisal Index) was then used to evaluate and obtain the best pharmacophore models of each target, which were then applied to screen the Traditional Chinese Medicine Database for potential active compounds in Chinese herbs. Four common used herbs were obtained, which contain the active compounds and can act on multiple targets, and were expected to have multiple activity of anti-AD disease.

Eight structure-based pharmacophore models of Interleukin-1β converting enzyme (ICE) inhibitors were generated by LigandScout based on ICE inhibitor complexes from the Protein Data Bank (PDB). A combinatorial screening method based on multiple pharmacophore models were proposed in present study, since the binding pockets of different complexes were different, the structure-based pharmacophore models have a high specificity and cannot cover all the active molecules. Based on the screening results of MDDR and the metrics of E and A%, a new metric CAI (comprehensive appraisal index) was defined and used to determine the threshold of hit frequency of molecules which screened by the combinatorial screening method. According to the threshold, the potential ICE inhibitors were then identified from traditional Chinese medicine with the method of combinatorial screening with eight models. The molecules hit by not less than five pharmacophore models were taken as the screening objects of ICE inhibitor, and 781 molecules were obtained.

The combustion process of polymer is a complex coupling of energy feedback from flame to fuel surface with degradation of polymer. In this paper, a series of comparative laboratory-scale experiments were carried out to study the effect of sample width on downward flame spread over the rigid polyurethane (RPU) foam, a typical thermal insulation material. The variations of some important parameters such as flame height, pulsation frequency and flame spread rate were measured and analyzed. Results show that if the width fixed, the parameters mentioned above independent with time. If the width less than 25cm, the sample can not burn completely. With the expand of width, average flame height and flame spread rate present the same chang trend that increase first and then decrease and finally reach a steady state, flame pulsation frequency increases first and then decreases since sample width more than 20cm. The heat transfer from flame and pyrolysis zone to virgin region is proportional to the height of flame, and mainly dominated by radioactive regime.

In this paper, forward and inverse position solution are analyzed for a novel 2UPR/1SPR special 3-DOF parallel mechanism. The moving platform of this mechanism have 1 translational DOF and 2 rotational DOFs. The inverse position solution of this mechanism was deduced by analytical method. The decoupling equation of position and posture parameters are formulated on the basis of structural constraint of the concerned mechanism. The forward position solution of this mechanism is achieved by numerical method.

A novel 3SPS/UP spatial 3-DOF parallel mechanism is studied. The studied mechanism is composed of a moving platform connected to a fixed platform by means of four actuated limbs. The three of the four limbs are SPS serial manipulators and the other one is UP serial manipulator. Each SPS limb consists of a spherical pair S connecting to the fixed platform, a prismatic pair P, and another spherical pair S connecting to the moving platform. The UP limb consists of eight Hoke joints U and a prismatic pair P. One side of the UP limb is connected to the fixed platform by Hoke joints U and another side is fixed to the moving platform. Moving character of this mechanism are analyzed by using the theory of screws. The moving platform of this mechanism have three translational DOFs

The aim of this article is to develop a new block monotone iterative method for the numerical solutions of a nonlinear elliptic boundary value problem. The boundary value problem is discretized into a system of nonlinear algebraic equations, and a block monotone iterative method is established for the system using an upper solution or a lower solution as the initial iteration. The sequence of iterations can be computed in a parallel fashion and converge monotonically to a maximal solution or a minimal solution of the system. Three theoretical comparison results are given for the sequences from the proposed method and the block Jacobi monotone iterative method. The comparison results show that the sequence from the proposed method converges faster than the corresponding sequence given by the block Jacobi monotone iterative method. A simple and easily verified condition is obtained to guarantee a geometric convergence of the block monotone iterations. The numerical results demonstrate advantages of this new approach. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011

This paper is concerned with finite difference solutions of a system of reaction-diffusion equations with coupled nonlinear boundary conditions and time delays. The reaction functions and the boundary functions are not necessarily quasimonotone, and the time delays may appear in the reaction functions as well as in the boundary functions. The investigation is devoted to the finite difference system for both the time-dependent problem and its corresponding steady-state problem. Some monotone iteration processes for the finite difference systems are given, and the asymptotic behavior of the time-dependent solution in relation to the steady-state solution is discussed. The asymptotic behavior result leads to some local and global attractors of the time-dependent problem, including the convergence of the time-dependent solution to a unique steady-state solution. An application and some numerical results to an enzyme-substrate reaction-diffusion problem are given. All the results are directly applicable to parabolic-ordinary systems and to reaction-diffusion systems without time delays.

This paper is concerned with the asymptotic behavior of the finite difference solutions of a class of nonlinear reaction diffusion equations with time delay. By introducing a pair of coupled upper and lower solutions, an existence result of the solution is given and an attractor of the solution is obtained without monotonicity assumptions on the nonlinear reaction function. This attractor is a sector between two coupled quasi-solutions of the corresponding ”steady-state" problem, which are obtained from a monotone iteration process. A sufficient condition, ensuring that two coupled quasi-solutions coincide, is given. Also given is the application to a nonlinear reaction diffusion problem with time delay for three different types of reaction functions, including some numerical results which validate the theoretical analysis.

A new monotone iterative method for the periodic boundary value problems of first order discrete systems is developed. The numerical results are given.

A new concept of a pair of upper and lower solutions is introduced for a boundary value problem of second order discrete system. A comparison result is given. An existence theorem for a solution is established in terms of upper and lower solutions. A monotone iterative scheme is proposed, and the monotone convergence rate of the iteration is compared and analyzed. The numerical results are given.

Almost monotone approximation is proposed for nonlinear two‐points problem. A general framework is given for studying the existence and uniqueness of numerical solutions. A discrete approximation with high accuracy is constructed. Nonlinear Jacobi iteration and Gauss–Seidel iteration are introduced to save work. The continuous approximation is also considered. The numerical results show the advantages of such an approach.

In a recent paper, Ren and Liu proposed and analyzed a high-order compact finite difference method for a class of fractional sub-diffusion equations with variable coefficients and nonhomogeneous Neumann boundary conditions. In this paper, we point out some deficiencies and errors found in that paper and make the corresponding revisions.

ZigBee is an emerging standard specifically designed for wireless personal area networks (WPANs) with a focus on enabling the wireless sensor networks (WSNs). It attempts to provide a low-data rate, low-power, and low-cost wireless networking on the device-level communication. In this paper, we have established a realistic indoor environment for the performance evaluation of a 51-node ZigBee wireless network. Several sets of practical experiments have been conducted to study its various features, including the (1) node connectivity, (2) packet loss rate, and (3) transmission throughput. The results show that our developed ZigBee platforms could work well under multihop transmission over an extended period of time.