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Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article concerns the Cauchy problem for the fractional semilinear pseudo-parabolic equation. Through the Green's function method, we prove the pointwise convergence rate of the solution. Furthermore, using this precise pointwise structure, we introduce a Sobolev space condition with negative index on the initial data and give the nonlinear critical index for blowing up. [ABSTRACT FROM AUTHOR]

Amongst the various fascinating types of material behavior featured by magnetic gels and elastomers are magnetostrictive effects. That is, deformations in shape or changes in volume are induced from outside by external magnetic fields. Application of the materials as soft actuators is therefore conceivable. Mostly, straight contraction or extension of the materials along a certain direction is discussed and investigated in this context. Here, we demonstrate that various further, different, higher modes of deformation can be excited. To this end, different spatial arrangements of the magnetizable particles enclosed by the soft elastic matrix, which constitute the materials, need to be controlled and realized. We address various different types of spatial configurations of the particles and evaluate resulting types of deformation using theoretical tools developed for this purpose. Examples are sheet-like arrangements of particles, circular or star-shaped arrangements of chain-like aggregates, or actual three-dimensional star-like particle configurations. We hope to stimulate with our work the development of experimental design and engineering methods so that selected spatial particle arrangements in magnetic gels and elastomers can be put to reality. Overall, we in this way wish to promote the transfer of these promising class of materials to real-world applications. • Overall deformations of magnetic elastomers depend on the arrangement of the magnetizable particles. • Analytical tools are developed to calculate the resulting overall deformations. • Higher modes of deformation can be excited as geared by appropriate positioning of the inclusions. • Resulting deformations can be chosen from a palette of evaluated structures. [ABSTRACT FROM AUTHOR]

Pseudospin symmetry (PSS) is a relativistic dynamical symmetry connected with the lower component of the Dirac spinor. Here, we investigate the conservation and breaking of PSS in the single-nucleon resonant states, as an example, using Green's function method that provides a novel way to precisely describe not only the resonant energies and widths but also the spacial density distributions for both narrow and wide resonances. The PSS conservation and breaking are perfectly displayed in the evolution of resonant parameters and density distributions with the potential depth: In the PSS limit, i.e., when the attractive scalar and repulsive vector potentials have the same magnitude but opposite sign, PSS is exactly conserved with strictly the same energy and width between the PS partners as well as identical density distributions of the lower components. As the potential depth increases, the PSS is broken gradually with energy and width splittings and a phase shift in the density distributions. [ABSTRACT FROM AUTHOR]

This paper is concerned with the problem of free vibration of an Euler-Bernoulli beam supported with an arbitrary number of translational springs of different constant stiffnesses. The natural frequencies and mode shapes are calculated by means of the Green's function method. Seven different boundary conditions are considered at both ends of the beam: fixed, pinned, sliding, free, translational spring, rotational spring and combined translational-rotational spring. Each boundary condition on one end is combined with all other boundary conditions on the other, yielding a total of 49 possible cases. It has been shown in this paper that a Green's function for any set of boundary conditions can be represented as a linear combination of function coefficients calculated for homogeneous boundary conditions, and also a new form of the general solution is formulated using this principle. Green's functions are calculated and tabulated for each of the 49 possible cases, which in essence closes the question of analytical solutions for this particular kind of problem using Green's functions. The tabulated solutions were used as the starting point in the derivation of the general formulae and to provide a new insight into the underlying mathematical structure of the solutions formulated with Green's functions. This can be of practical interest to the end user who wishes to implement them in computer code. The validity of the obtained solutions is demonstrated with examples, whose solutions are compared to the results in the published literature and to the results obtained with FEM. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The hyperthermia is an efficient technique for tumor treatment, in which the tumor is subjected to a heating source, such as laser, supersonic or electromagnetic field. In order to improve the therapeutic efficiency and to protect the surrounding healthy tissues, gold nanoshells are embedded in the tumor as the additive to make it absorb more thermal energy than the healthy tissues. In the present study, a one-dimensional three-layered model is established to investigate the thermal response of the bio-tissue in the hyperthermia treatment for subcutaneous tumor. The governing equations are solved analytically by using the Green's function method and the Henriques' model is employed to evaluate the degree of thermal damage in the target tissue. The influences of the volumetric density of gold nanoshells on the temperature distribution and thermal damage are discussed in detail. When the gold nanoshells are embedded with a proper density, it can improve the efficiency of tumor killing and protecting the subcutaneous tissue from being burnt. The closed-form solution for the governing equations in multilayered tissues can be a theoretical guideline to selection of appropriate parameters of the gold nanoshells. Highlights • Gold nanoshells are embedded into tumor in laser therapy. • 1-dimensional three-layered model of heat conduction is established. • Expressions of temperature and thermal damage are derived analytically. • Distributions of temperature and thermal damage in the three layers are discussed. • Influences of nanoshell density on temperature and thermal damage are discussed. [ABSTRACT FROM AUTHOR]

We investigate the Cauchy problem for the 3D magneto-hydrodynamics equations with only horizontal dissipation for the small initial data. With the help of the dissipation in the horizontal direction and the structure of the system, we analyze the properties of the decay of the solution and apply these decay properties to get the global regularity of the solution. In the process, we mainly use the frequency decomposition in Green's function method and energy method. [ABSTRACT FROM AUTHOR]

The mathematical theory of integral transformations has been developed for finding analytical solutions of the generalized nonstationary heat conduction equation for a limited canonical-type region (infinite plate, solid cylinder, sphere) simultaneously in the Cartesian, cylindrical, and spherical coordinate systems. Improved solutions in the form of Fourier–Hankel′s series are suggested that absolutely and uniformly converge up to the boundary of the region and represent fundamentally new constructions of the analytical theory of thermal conductivity of solid bodies very convenient for conducting numerical experiments in the practical thermal physics. The Green′s function method has been developed: an integral relation is suggested for writing analytical solutions of boundary-value problems for the generalized equation of nonstationary heat conduction in terms of inhomogeneities in the equation and boundary-value conditions in the initial formulation of the problem, and the corresponding Green′s functions are presented. [ABSTRACT FROM AUTHOR]

The effective spin Hamiltonian method has drawn considerable attention for its power to explain and predict magnetic properties in various intriguing materials. In this review, we summarize different types of interactions between spins (hereafter, spin interactions, for short) that may be used in effective spin Hamiltonians as well as the various methods of computing the interaction parameters. A detailed discussion about the merits and possible pitfalls of each technique of computing interaction parameters is provided.

Aquifer thermal energy storage (ATES) system plays an important role in application of renewable energy, efficient energy utilization, and reduction of CO 2 emission. To realize the successful operation of ATES systems, it is essential to understand the thermal behaviors thoroughly during heat injection. Serving as a powerful tool, analytical model is widely adopted while the existing analytical models usually simplify ATES systems by ignoring aquifer transverse thermal conduction and rock longitudinal thermal conduction. This study develops a novel analytical model for an ATES system, which accounts for thermal convection, dispersion, longitudinal and transverse thermal conduction in the aquifer, and longitudinal and transverse thermal conduction in the surrounding rocks. The Green's function method is applied to derive the semi-analytical solutions of temperature. A global sensitivity analysis is conducted to analyze the relative importance of each parameter. The results indicate that ignoring the aquifer transverse thermal conductivity will overestimate the temperature in the aquifer and ignoring the caprock longitudinal thermal conductivity may underestimate the heat loss in ATES systems. Similar conclusion can be made about the bedrock longitudinal thermal conductivity. The global sensitivity analysis indicates that temperature is sensitive to the changes in the flow velocity, thermal dispersivity and aquifer thickness. [ABSTRACT FROM AUTHOR]

We investigate the structure and formation of charmed meson–nucleus systems, with the aim of understanding the charmed meson–nucleon interactions and the properties of the charmed mesons in the nuclear medium. The D¯ mesic nuclei are of special interest, since they have tiny decay widths due to the absence of strong decays for the D¯N pair. Employing an effective model for the D¯N and DN interactions and solving the Klein–Gordon equation for D¯ and D in finite nuclei, we find that the D−–11B system has 1s and 2p mesic nuclear states and that the D0–11B system binds in a 1s state. In view of the forthcoming experiments by the PANDA and CBM Collaborations at the future FAIR facility and the J-PARC upgrade, we calculate the formation spectra of the [D−–11B] and [D0–11B] mesic nuclei for an antiproton beam on a 12C target. Our results suggest that it is possible to observe the 2p D− mesic nuclear state with an appropriate experimental setup.

Non-equilibrium Green's function method is applied to study the spin thermoelectric effects in a four-quantum-dot ring with two of the quantum dots magnetized. The influence of magnetic configuration on the spin thermoelectric transport through the system is investigated. In some magnetic configurations, a significant spin Seebeck coefficient S s can be generated with the variation of the quantum dot (QD) energy level. Appropriately tuning the QD energy level can let the present device work as a pure spin-up (spin-down) or a pure-spin-current thermal generator. The combined effect of the magnetization and magnetic flux (or Rashba spin-orbit coupling) is also investigated. Finally, the charge figure of merit Z c T and spin figure of merit Z s T are evaluated, it is found that the magnitude of the spin figure of merit can be comparable to that of the charge counterpart. [ABSTRACT FROM AUTHOR]

Abstract The asymptotic wave behavior of solution for the Euler equations with damping in R + n is investigated around a given constant equilibrium in this paper. Three classical boundary condition cases are considered here. New approaches and techniques are introduced to deal with the multi-dimensional case for the system. For the linearized problem, by comparing symbols in the transformed tangential–spatial and time space, we show that its Green's function can be described in terms of the fundamental solution for the Cauchy problem and reflected fundamental solution coupled with a boundary operator. Our approaches help us to simplify the Green's function to the essential part and benefit the follow-up nonlinear analysis. For the nonlinear problem, we prove the pointwise decaying rate with the help of the Duhamel's principle. [ABSTRACT FROM AUTHOR]

The near-field radiative heat flux between two two-dimensional sinusoidal grating surfaces made of doped-silicon is investigated by the finite difference time domain (FDTD) method. The parameter Λ, which is defined as the ratio of the amplitude to the period of the two-dimensional sinusoidal grating surface, is used to characterize the surface feature. When the amplitude is much smaller than the period, the surface effect is not significant to modify the near-field radiative heat flux between two smooth films. However, when the amplitude is comparable with the period, the near-field radiative heat flux between two smooth films can be enhanced remarkably. The coupling of the localized surface modes between the may be responsible for the variation of the near-field radiative heat flux when the parameter Λ is changed. Moreover, the effect of the lateral displacement of the films on the near-field radiative heat flux is also studied. The results indicate that the near-field radiative heat flux will achieve the maximum value when the peaks of the sinusoidal gratings are aligned. This work will be valuable to research on contactless thermal management in nanoscale. [ABSTRACT FROM AUTHOR]

Abstract Underground tunnel temperature is an essential factor that influences both the environment and energy consumption in subways. Therefore, any formalism that addresses underground tunnel temperature is required to take into account the inhomogeneity in the thermal properties of the soil and transition phases in the long-term heat transfer process. In this study, a two-dimensional unsteady heat transfer formalism based on a Green's function method (GFM) and finite element method (FEM) was proposed to consider the realities in underground tunnels. The boundaries in this model were classified into air–soil interface, soil–tunnel interface, and distant boundary. Moreover, a case study was conducted and validated through simulations and experiments. A satisfactory agreement was achieved between the simulation results and field measurement data from Guangzhou Metro Line7 and Line5, which are newly built and 10-year old operational subway lines, respectively. The results from the case study indicate that the proposed formalism has very good prediction capability to describe the subway tunnel temperature under various operation conditions. Highlights • Proposing the formalism to solve heat transfer process in underground tunnels. • Considering the influence of soil inhomogeneity in long-term heat transfer simulation. • Simulation and experiment validate the prediction capability of underground tunnel temperature under various operation conditions. [ABSTRACT FROM AUTHOR]

In this paper, we consider the half-space problem for a parabolic–hyperbolic system arising from tumor angiogenesis. Under a mixed type boundary condition, we construct the Green's function for half-space problem by relating it with fundamental solution for an initial value problem. After differential equation method for the boundary operator and proper estimates for additional exponential factors generated by the asymmetry of characteristics, one reduces the Green's function (for initial-boundary value problem) into fundamental solution (for Cauchy problem) which could be estimated by singularity removal, long wave-short wave decomposition and weighted energy method outside cone. We finally obtain the pointwise estimate for Green's function which results in the pointwise convergence rate for nonlinear problem. The Green's function constructed is precise enough to avoid a priori estimate for derivatives by energy method. The half space problem studied here is a main ingredient for future study of shock profile with presence of boundary. [ABSTRACT FROM AUTHOR]

In this paper, the spin-dependent transport of a spin-valve, based on bilayer graphene in which the AA-stacked bilayer zigzag graphene nanoribbon (BLG) connected to two ferromagnetic ( FM ) semi-infinite single-layer zigzag graphene nanoribbons (FM/BLG/FM system), is numerically studied. Using the non-equilibrium Green's function method and tight-binding model in the framework of Landauer-Büttiker formalism, the spin-dependent transmission function, current and tunnel magnetoresistance of the system are calculated. Results show that the transmission function is always nonzero near the zero energy for the parallel alignment of electrode magnetizations, while it is zero for the antiparallel alignment due to the band-selective rule. Consequently, there is a region for the tunnel magnetoresistance with the value of 100 % . The magnitude of this region depends on the strength of magnetization in ferromagnetic electrodes. Also, the effects of bilayer/single-layer coupling geometry,inter-layer coupling strength and width of BLG on the spin-dependent transport of the system are investigated. These results can be useful for designing graphene based spintronic devices. [ABSTRACT FROM AUTHOR]

We have studied the role of solitons on the spin-dependent transport properties of through a double-stranded DNA (dsDNA) molecule attached to two the semi-infinite ferromagnetic (FM) electrodes. The work is based on a tight-binding Hamiltonian model within the framework of a generalized Green's function technique and relies on the Landauer-Bütikker formalism as the basis for studying the current-voltage characteristic of this system. The conductance properties of the spin system are studied for a ladder model for poly (dG)-poly (dC) DNA molecule. Our calculations indicate that the presence of a homogeneous distribution of the solitons along the molecular, as a sublattice of the correlated solitons, gives rise to significant enhancement in the density of states within the bandgap and large enhancement in conductance and the current–voltage characteristic. It is also shown that tunnel magnetoresistance (TMR) decreases in compared with TMR obtained in the absence of solitons. [ABSTRACT FROM AUTHOR]

This article deals with the exact thermo-mechanical static responses of a curved circular beam by Green's function method. To find the solution, the related governing differential equations are found using the Hamilton's principles. They are combined into two six-order ordinary inhomogeneous differential equations. To form the Green's problem, the adjoint differential operator along with corresponding boundary conditions is found from the inner product calculations. It is noteworthy that the lateral temperature distribution leads to both in-plane and out-of-plane deformations. This important point has not been mentioned in the previous studies. Moreover, the radially distributed temperature results in no out-of-plane displacements. Finally, the answers of some numerical tests confirmed the accuracy of the proposed solution method. [ABSTRACT FROM AUTHOR]

In this article, the deflection functions of nanobeams are found by employing the well-known Green's function method. Based on Eringen's nonlocal elasticity theory, stress gradient model is employed to formulate the problem. Different boundary conditions, including, clamped–clamped, clamped-free, simply supported-simply supported and clamped-simply supported are studied. The beams are assumed to be under arbitrary distributed or concentrated loads. By presenting some new Green's integral formulations, three different ways of treating the nonlocal terms are suggested. The specificity of inhomogeneous boundary conditions for the stress gradient nonlocal model is found. A particular property is a possible loss of the symmetry of Green's functions for nonlocal boundary conditions. To validate the proposed results, findings are compared with the available ones in the literature. [ABSTRACT FROM AUTHOR]

Determining thermal conductivity of ground plays an important role in designing procedure of ground source heat pump (GSHP) systems. In this paper new modified 2D analytical models which are depending on thermal conductivity of ground are derived and results are compared with experimental ones. In an experimental study, a single borehole ground heat exchanger (GHE) with polyethylene U-tube pipe is considered for two different regions. Fluid is pumped into the pipes in a specific temperature and inlet and outlet temperatures are measured as well as volumetric flow rate. Analytical results curves are fitted to experimental one and thermal conductivities of ground are calculated for each region. Based on validated analytical models, long term performance of a single borehole GHE is determined. Additionally, temperature distributions around borehole GHE are investigated analytically in region 1 (N.D.B. residence region). Analytical models given in this study can easily help designers to evaluate thermal conductivity of ground and thermal performance of the borehole GHEs. [ABSTRACT FROM AUTHOR]

Analytical solution for a rigid line inclusion embedded in an infinite-extended plane under non-uniform loading is still a challenging problem in inclusion mechanics, which has both theoretical and applied significance in material engineering. In this paper, by directly employing Kolosov-Muskhelishvili stress potentials, a rigid line inclusion interacting with a generalized singularity is addressed in the framework of plane deformation, with the help of the superposition principle. It should be pointed out that the generalized singularity in this study can represent a point force, an edge dislocation, a point moment, a point nucleus of strain, and even remote uniform load, etc. The solutions can be used as kernel functions for integral equation formulations of rigid line inclusion-substrate system models using the Green’s function method. With this framework, stress field and stress intensity factors at the line inclusion ends are analyzed. The application of the solutions is demonstrated with two simple examples: (i) the rigid line inclusion under remote loading is studied, and it is strictly confirmed with rigorous proof that the remote shear load will not arouse stress concentration; (ii) a rigid line inclusion interacting with a dislocation is investigated, and the full solution is given. These examples also partially validate the general solution derived this study. [ABSTRACT FROM AUTHOR]

The forced vibration of fluid conveying pipe with elastic support was investigated. Euler-Bernoulli beam was adopted to simplify the mechanical model of the pipe. Green's Function method was used to deduce the dimensionless differential equation of forced vibration and Green's Function of pipes with general supporting formats was obtained. Finally， the general expression of the deflection was obtained. On this basis， dynamic responses of the pipe with one end fixed and the other elastically supported was studied. Differential Transformation method and Galerkin's Method were utilized to verify the validity and accuracy of the proposed method， and the responses of the pipe under concentrated and distributed force were investigated. The proposed model has advantages compared with other numerical methods because it is capable for offering precise closed solutions. [ABSTRACT FROM AUTHOR]

Electrostatic interaction energy W between two point charges in a three-layer plane system was calculated on the basis of the Green’s function method in the classical model of constant dielectric permittivities for all media involved. A regular method for the calculation of W ( Z , Z ′ , R ) , where Z and Z ′ are the charge coordinates normal to the interfaces, and R the lateral (along the interfaces) distance between the charges, was proposed. The method consists in substituting the evaluation of integrals of rapidly oscillating functions over the semi-infinite interval by constructing an analytical series of inverse radical functions to a required accuracy. Simple finite-term analytical approximations of the dependence W ( Z , Z ′ , R ) were proposed. Two especially important particular cases of charge configurations were analyzed in more detail: (i) both charges are in the same medium and Z = Z ′ ; and (ii) the charges are located at different interfaces across the slab. It was demonstrated that the W dependence on the charge−charge distance S = R 2 + Z − Z ′ 2 differs from the classical Coulombic one W ∼ S − 1 . This phenomenon occurs due to the appearance of polarization charges at both interfaces, which ascribes a many-body character to the problem from the outset. The results obtained testify, in particular, that the electron−hole interaction in heterostructures leading to the exciton formation is different in the intra-slab and across-slab charge configurations, which is usually overlooked in specific calculations related to the subject concerned. Our consideration clearly demonstrates the origin, the character, and the consequences of the actual difference. The often used Rytova−Keldysh approximation was analyzed. The cause of its relative success was explained, and the applicability limits were determined.

A mathematical theory of constructing integral transforms and formulas of their inversion for the generalized equation of nonstationary heat conduction in an infinite region, bounded from the inside by a plane, a cylindrical, or a spherical surface, and the Green′s function method have been developed. Integral relations for analytical solutions of boundary-value problems in the indicated region are proposed. Illustrative examples are considered. [ABSTRACT FROM AUTHOR]

In ground source heat pump (GSHP) applications, long term performance prediction of a borehole is an important issue since performance of a borehole ground heat exchanger decreases by the life time of the system. Therefore, it is important to find a reliable method determining the long term performance of a borehole. In this study, a new 1D analytical expression for heat transfer rate (HTR) per unit length of a borehole is derived at constant borehole wall temperature condition by using Green's function method (GFM). A 50 m-depth borehole containing U-tube polyethylene pipes with 32 mm outside and 26.6 inside diameter is considered. Experimental measurements are done by pumping warm water of 40 °C into the pipe system for 120 h. Variation of HTR value per length of borehole in time is determined from the experimental data. Analytical results based on GFM are verified by experimental measurements. Based on the validated analytical model, long term HTR values (thermal performance) per length of borehole are predicted. Verification of numeric and experiment results illustrates the compromise of them. Furthermore, temperature distribution around borehole is investigated by using new given analytical expression. Engineers can use analytical models that are given in this study in designing of GSHP systems. [ABSTRACT FROM AUTHOR]

Based on the tight-binding model and a generalized Green's function method, we theoretically investigated the electron transport properties of T-shaped silicene nanoribbons (TsSiNRs) structure composed of an armchair SiNR (ASiNR) with a sidearm connected to two semi-infinite ASiNR leads. In particular, we demonstrated that the transport properties sensitively depend on the sidearm width and length. Besides, we found that the metal to semiconductor transition occurs with the increase of the spin-orbit interaction (SOI) strength. The effect of the external perpendicular electric field on electron transport is also investigated and it is found that potential energy causes to the decrease of the energy gap leading to semiconductor to metallic transition. [ABSTRACT FROM AUTHOR]

In this study, analytical solutions of one-dimensional pollutant transport originating from instantaneous and continuous point sources were developed in groundwater and riverine flow using both Green’s Function Method (GFM) and pertinent coordinate transformation method. Dispersion coefficient and flow velocity are considered spatially and temporally dependent. The spatial dependence of the velocity is linear, non-homogeneous and that of dispersion coefficient is square of that of velocity, while the temporal dependence is considered linear, exponentially and asymptotically decelerating and accelerating. Our proposed analytical solutions are derived for three different situations depending on variations of dispersion coefficient and velocity, respectively which can represent real physical processes occurring in groundwater and riverine systems. First case refers to steady solute transport situation in steady flow in which dispersion coefficient and velocity are only spatially dependent. The second case represents transient solute transport in steady flow in which dispersion coefficient is spatially and temporally dependent while the velocity is spatially dependent. Finally, the third case indicates transient solute transport in unsteady flow in which both dispersion coefficient and velocity are spatially and temporally dependent. The present paper demonstrates the concentration distribution behavior from a point source in realistically occurring flow domains of hydrological systems including groundwater and riverine water in which the dispersivity of pollutant’s mass is affected by heterogeneity of the medium as well as by other factors like velocity fluctuations, while velocity is influenced by water table slope and recharge rate. Such capabilities give the proposed method’s superiority about application of various hydrological problems to be solved over other previously existing analytical solutions. Especially, to author’s knowledge, any other solution doesn’t exist for both spatially and temporally variations of dispersion coefficient and velocity. In this study, the existing analytical solutions from previous widely known studies are used for comparison as validation tools to verify the proposed analytical solution as well as the numerical code of the Two-Dimensional Subsurface Flow, Fate and Transport of Microbes and Chemicals (2DFATMIC) code and the developed 1D finite difference code (FDM). All such solutions show perfect match with the respective proposed solutions. [ABSTRACT FROM AUTHOR]

Based on tight-binding model and a generalized Green's function method in Landauer-Büttiker formalism, the next nearest-neighbor (NNN) effects on the spin-dependent transport properties of a poly(G)-poly(C) DNA molecule sandwiched between ferromagnetic 3-dimensional electrodes are numerically investigated. Our results show that the spin-dependent transport characteristics, including the spin-dependent transmission probability, current-voltage characteristics, noise power, Fano factor ( F), and tunnel magnetoresistance (TMR) are strongly influenced by NNN effect. Results show that the inclusion of NNN effect can broaden transmission spectra and leads to semiconductor-metal transition in the system. Therefore, the spin-dependent current and noise power amplitudes increase. The Poisson limit ( F=1) region decreases due to the presence of NNN effect, where the inclusion of diagonal hopping integrals between the DNA sites increases electron correlations. Furthermore, with increasing diagonal hopping integrals strength between the DNA sites, the first sharp decrease of TMR happens in lower bias voltage and the region of the maximum value of TMR decreases. [ABSTRACT FROM AUTHOR]

Exploitation of unconventional reservoirs is enabled by multi-fractured horizontal wells. Hydraulic fractures are created with the purpose of enhancing fluid conductivity in such low permeability formation. These hydraulic fractures, along with the intricate structure of the reservoir, such as the presence of natural fractures, result in a highly heterogeneous system and introduces significant challenges with respect to obtaining a proper description of fluid movement. This paper proposes the use of anomalous transport concept based on fractional-time derivative to model gas flow through highly heterogeneous unconventional reservoirs. A modified Darcy's law that accounts for non-local temporal effects, i.e. history, is adopted to account for the complex flow mechanisms encountered in such disordered media with a wide range of heterogeneity scales. Studies previously developed on this topic solely focused on slightly-compressible fluid transport without further consideration of the nonlinear dependency of fluid properties to pressure. In this regard, the development of predictive models simultaneously considering reservoir heterogeneity and the nonlinear nature of gas transport is yet to be accomplished. In this work, transient pressure diffusion is modeled by the so-called nonlinear Generalized Diffusivity Equation (nGDE), and an integral solution is derived based on Green's function method. It is observed that for the cases of higher heterogeneity level, higher pressure drawdown is required to maintain a given specified (constant) rate, significantly increasing the deviation of the system response from its linear (slightly-compressible) behavior. This finding corroborates the importance of properly accounting for the nonlinear behavior of gas properties and highlights that available analytical solutions suffer drawbacks when extrapolated to compressible flow scenarios. • Anomalous transport is used to model heterogeneity effects on flow characteristics. • Nonlinear Generalized Diffusivity equation derived to model gas transport. • Nonlinear nature of gas flow behavior is rigorously modeled. • Novel solution based on Green's function method incorporates heterogeneity effects. [ABSTRACT FROM AUTHOR]

In this paper, a laboratory method based on equivalent dynamic load reconstruction is proposed for the identification of oil-film coefficients. When modeling the rotor, the oil-film supports are considered as its dynamic load boundary conditions. Consequently, the identification of oil-film coefficients is first converted to the reconstruction of equivalent dynamic loads. Through Green's function method and regularization, the equivalent dynamic oil-film loads can be steadily and precisely reconstructed. Then, according to the mechanical relationships between the oil-film properties and the corresponding equivalent loads, the oil-film stiffness and damping coefficients are identified using least square scheme. A rotor structure with two journal bearings is investigated and the identification results of oil-film coefficients demonstrate the validity and accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Some analytical solutions of one-dimensional advection-diffusion equation (ADE) with variable dispersion coefficient and velocity are obtained using Green's function method (GFM). The variability attributes to the heterogeneity of hydro-geological media like river bed or aquifer in more general ways than that in the previous works. Dispersion coefficient is considered temporally dependent, while velocity is considered spatially and temporally dependent. The spatial dependence is considered to be linear and temporal dependence is considered to be of linear, exponential and asymptotic. The spatio-temporal dependence of velocity is considered in three ways. Results of previous works are also derived validating the results of the present work. To use GFM, a moving coordinate transformation is developed through which this ADE is reduced into a form, whose analytical solution is already known. Analytical solutions are obtained for the pollutant's mass dispersion from an instantaneous point source as well as from a continuous point source in a heterogeneous medium. The effect of such dependence on the mass transport is explained through the illustrations of the analytical solutions. [ABSTRACT FROM AUTHOR]

Using the Green's function method in Hubbard model we investigate the spin-polarized currents in a triangle Quantum dot (TQD) connected to normal metal electrodes (M/TQD/M system) in the presence of Coulomb interaction. The spin-dependent currents generated by a voltage or temperature gradient in the M/TQD/M system. Results show that in both voltage-driven and temperature-driven cases the M/TQD/M system can generate spin-polarized currents with nonlinear behavior. Also, 100% current spin polarization (SP) ratio can be observed only in temperature-driven case. Besides, the spin-dependent currents and SP ratio can be interestingly controlled with the QD on-site energy, dots' level detuning factor and spin polarization factor. These results may be useful to design future spin-thermoelectric devices based on QDs. • Spin-polarized transport through a triangle Quantum dot is investigated. • The system can generate spin-polarized currents with nonlinear behavior. • 100% SP ratio can be observed only in temperature-driven case. [ABSTRACT FROM AUTHOR]

A one-dimensional unsteady state mathematical model of coupled heat and mass transfer equations is accomplished to simulate the convective drying of cylindrical quince slices with axis parallel to the hot air flow. The semi-analytical proposed solution method considers fundamentals of the convective drying process and takes internal resistances to temperature and moisture content into account. Green's function method (GFM) is used due to existence of time dependent boundary conditions. In the present study, unlike classic problems, evaporation term initiate a strong coupling between heat and mass transfer equations and therefore in the present study the basic idea of numerical solutions which is repetition and correction, is used to present a novel analytical solution and correct it. In addition the effects of Biot number and relative humidity on drying kinetics are investigated. The agreement between published experimental results and model predictions is remarkable. [ABSTRACT FROM AUTHOR]

The design of capacitive sensors and devices for new and emerging applications would benefit from simple and reliable methods to estimate the capacitance between conductors in terms of the capacitance of the isolated bodies and of the distance between them. The coefficients of potential and capacitance of a pair of conductor are approximated with the first terms of an expansion formula in the inverse of their distance. The form given applies to conductors of generic shapes and position in space. A comparison with the exact value for two spheres shows agreement even for rather small distances. [ABSTRACT FROM AUTHOR]

High-speed connectors contribute to system-level electromagnetic interference (EMI). Radiation from antenna-mode current and transmission-line (TL)-mode current is briefly reviewed with a backplane connector and an optical cage connector. The radiation from the high-speed connector with TL-mode current is analyzed in detail. The possible radiation mechanisms are analyzed respectively through Green's function method, steepest descent method, and electromagnetic compatibility studio method of moment. Design guidelines of high-speed connectors for EMI mitigation are proposed based on the analysis of radiation physics. [ABSTRACT FROM AUTHOR]

We theoretically investigated the spin-dependent transport through a T-shaped graphene nanoribbon (TsGNR) based spin-valve consisting of armchair graphene sandwiched between two semi-infinite ferromagnetic armchair graphene nanoribbon leads in the presence of an applied uniaxial strain. Based on a tight-binding model and standard nonequilibrium Green’s function technique, it is demonstrated that the tunnel magnetoresistance (TMR) for the system can be increased about 98% by tuning the uniaxial strain. Our results show that the absolute values of TMR around the zero bias voltage for compressive strain are larger than tensile strain. In addition, the TMR of the system can be nicely controlled by GNR width. [ABSTRACT FROM AUTHOR]

A theoretical study is presented to investigate the structural and electronic properties of trans -polyacetylene ( trans -PA) molecule under local strain. The influence of a local bending or compression of the space between neighboring carbon atoms on the band gap of the molecule was studied. Making use of an effective difference equation based on tight-binding procedure the band structure of trans -PA has been calculated. Our results indicate that the energy gap of the strained molecule modified significantly which affects the electronic properties of the molecule. We found that the size of the molecular gap is proportional to the bending angle so that for the bending perpendicular to π -orbitals plane the band gap reduced drastically and for the parallel one the band gap gradually increased. Furthermore, the current–voltage characteristics of the strained trans -PA molecule are studied. We found that under the local strain the threshold voltage for the current flow through the bent molecule decreased (increased) depending on the bending is perpendicular (parallel) to the molecule plane. [ABSTRACT FROM AUTHOR]

Recently, substantial attention has been paid to the strain sensitivity of the carbon nanotubes' (CNTs') electronic properties. In this study, the relationships between the geometric structures and electronic states of zigzag CNTs under uniaxial compressive strain were investigated. We found that different factors dominate the electronic states of zigzag CNTs depending on the strain regions: the initial stage of the strain loading, which lasts until column-buckling deformation begins, and the strain regions corresponding to column- and shell-buckling deformations. Because shell-buckling deformation significantly increases the π-orbital angle, the angle between the ρ orbital axis vectors of adjacent atoms, strong localization of the density of states (LDOS) occurs in the buckled area. We also analyzed the current able to pass through deformed CNTs using a tight-binding-based Green's function approach and determined that the current can be significantly suppressed by applying uniaxial compressive strain. Our method of predicting the electronic state of a deformed CNT based on the π-orbital angle is expected to be useful for predicting the electronic properties of CNT-based electronic devices and sensors. [ABSTRACT FROM AUTHOR]

We investigate the structure and formation of charmed meson–nucleus systems, with the aim of understanding the charmed meson–nucleon interactions and the properties of the charmed mesons in the nuclear medium. The D ¯ mesic nuclei are of special interest, since they have tiny decay widths due to the absence of strong decays for the D ¯ N pair. Employing an effective model for the D ¯ N and DN interactions and solving the Klein–Gordon equation for D ¯ and D in finite nuclei, we find that the D − – 11 B system has 1 s and 2 p mesic nuclear states and that the D 0 – 11 B system binds in a 1 s state. In view of the forthcoming experiments by the PANDA and CBM Collaborations at the future FAIR facility and the J-PARC upgrade, we calculate the formation spectra of the [ D − – 11 B] and [ D 0 – 11 B] mesic nuclei for an antiproton beam on a 12 C target. Our results suggest that it is possible to observe the 2 p D − mesic nuclear state with an appropriate experimental setup. [ABSTRACT FROM AUTHOR]

In this paper we prove the existence of the unique global classical solution with small initial data to the Cauchy problem of a scalar conservation law with degenerate diffusion by establishing the uniform a priori decay estimates of solutions. In order to compensate the degeneracy on the x 1 direction by the diffusion on other directions, we introduce the frequency decomposition method and obtain the low frequency estimate and the high frequency estimate of the solution by the Green's function method and energy method respectively. [ABSTRACT FROM AUTHOR]

Based on Green's function method, we have conducted a systematic numerical investigation on the characteristics of local density of optical states of a tapered grated waveguide and other related parameters such as field profiles, transmission and scattering loss at left and right resonant states. The tapered grated sections are additional corrugated sections at both edges of a regular grated waveguide. We consider two different variations of the corresponding sections namely the uniform and non-uniform corrugation depth configurations. It is found that the characteristics of the local density of optical states for both variations at resonant states are different, especially for the left resonant state. In the mean time, compared to the other cases, a relatively distinct characteristic is also found on the transmission and scattering loss parameters of uniform variations at right resonant case. [ABSTRACT FROM AUTHOR]

The magnetic properties of a mixed spin-1/2 and spin-1 Heisenberg ferrimagnetic system on a two-dimensional square lattice are investigated by means of the double-time Green's function technique within the random phase decoupling approximation. The role of the nearest-, next-nearest-neighbors interactions and the exchange anisotropy in the Hamiltonian is explored. And their effects on the critical and compensation temperature are discussed in detail. Our investigation indicates that both the next-nearest-neighbor interactions and the anisotropy have a great effect on the phase diagram. [ABSTRACT FROM AUTHOR]