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In the present paper, we devote our effort to a nonlinear inverse problem for simultaneously recovering the potential function and the fractional orders in a multi-term time-fractional diffusion equation from the noisy boundary Cauchy data in the one-dimensional case. The uniqueness for the inverse problem is derived based on the analytic continuation, the Laplace transformation and the Gel’fand–Levitan theory. Finally, the Levenberg–Marquardt regularization method with a regularization parameter chosen by a sigmoid-type function is applied for finding a stable approximate solution. Three numerical examples are provided to show the effectiveness of the proposed method.

Marine geological disasters, such as seabed liquefactions, submarine landslides, debris flows and turbidity currents, are all closely related to the accumulation of wave-induced excess pore pressure in the seabed. Due to the limitations of physical model experiment and in-situ observations, numerical analysis has become an important method to explore the microscopic mechanism of the accumulation of excess pore pressure. Based on the discrete element porous density flow method, we simulated the changing process of excess pore pressure in seabed sediment in this study, comparing with laboratory flume experiment. The simulation results reproduce the changing process of excess pore pressure in the laboratory flume experiment. The excess pore pressure occurs in the surface of seabed and gradually transfers to the deep layer, tending to a stable value. Thus, the discrete element porous density flow method is well suitable for simulating the accumulation of wave-induced excess pore pressure. Furthermore, the method constitutes a promising tool to study the microscopic mechanism of seabed liquefaction.

Molecular dynamics simulations were carried out to investigate the hydration of Na+ ion in the nanochannels. The height of the channels varies from 0.65 nm to 3.0 nm, and the surface charge density varies from 0 to -0.2991 C/m2. The simulation results showed that the channel height and surface charge had special effect on the hydration of Na+ ion, and the peak height of radial distribution functions and coordination number increased as the channel height and surface charge density decreased. In the region of electrical double layer, hydration radius increased with the decreased of the channel height and the surface charge density, but the hydration radius of the Na+ ion of the bulk region was kept at a constant.

Using molecular dynamics simulations, the impact of the thermal motion of atoms in silicon walls on the water distribution confined in nanochannel has been investigated. The results show that thermal motion of silicon atoms has marginal effect on water distribution when the surface was not charged. However, when the surface is charged, the thermal motion of silicon atoms decreases the adsorbed peak of water molecular, and moves the position of the Na+ ion concentration peak far away from the surface.

Prefabricated prefinished volumetric construction (PPVC) has a lot of advantages, including environmental protection, saving money, reducing on-site manpower and so on. Many countries advocate the development of PPVC, the decision making of PPVC construction becomes critical important. This study aims to developing a scoring approach based on Knowledge-Based Decision Support System (KBDSS) for PPVC implementation. To achieve this goal, 19 key decision-making factors (DMFs) were identified from literature reviews first, subsequently, a questionnaire survey was conducted on 41 construction organizations in Singapore and using a five-point rating scale. Then create a PPVC scoring approach by using the data from the questionnaire, this scoring approach will developing a program named KBDSS-PPVC, by using the Microsoft Excel and Microsoft Visual Basic for Applications (VBA). Finally, four industry experts will be invited to validate the feasibility of KBDSS-PPVC and scoring their current construction projects, this program can also give corresponding recommendations according the score. The results of validation showed the developed system really could provide some available suggestions for industry practitioners on the decision-making for PPVC implementation, this study complements the current knowledge system on PPVC decision-making and provides the basis for further research.

Cobalt ferrite power CoFe2O4 was synthesized through the chemical co-precipitation method. The structure, morphology and microwave absorbing properties were studied by changing raw materials, annealing temperature and experimental steps. The measurements of X-ray diffraction and scanning electron micrograph suggest that annealed CoFe2O4 sample is still a spinel structure. Moreover, the crystalline and grain sizes become large with the enhancement of annealing temperature. The measurements of microwave absorbing properties show that the reflection loss decreases continuously, and the wavelength of maximum absorption loss shift to short-wave limit as the sample thickness increases.

This paper is devoted to identifying a time-dependent source term in a multi-dimensional time-fractional diffusion equation from boundary Cauchy data. The existence and uniqueness of a strong solution for the corresponding direct problem with homogeneous Neumann boundary condition are firstly proved. We provide the uniqueness and a stability estimate for the inverse time-dependent source problem. Then we use the Tikhonov regularization method to solve the inverse source problem and propose a conjugate gradient algorithm to find a good approximation to the minimizer of the Tikhonov regularization functional. Numerical examples in one-dimensional and two-dimensional cases are provided to show the effectiveness of the proposed method.

Angle-resolved photoemission with synchrotron light is used to determine the band structure of five- and six-layer films of Cu grown epitaxially on Pd(001) and on Pt(001). The films have body-centred-tetragonal structure resulting from the large plane strains of 8 to 9% imposed by the substrates. The band structure is the same, within experimental error, for films grown either on Pd(001) or Pt(001), and is similar to that of stable FCC Cu.

A microstructure-dependent piezoelectric beam model was developed using a variational formulation, which is based on the modified strain gradient theory and the Timoshenko beam theory. The new model contains three material length scale parameters and can capture the size effect, unlike the classical beam theory. To illustrate the new piezoelectric beam model, the static bending and the free vibration problems of a simply supported beam are numerically solved. These results may be useful in the analysis and design of smart structures that are constructed from piezoelectric materials.

Well-aligned diamond nanotips are fabricated by etching as-grown diamond thin films using a Kaufman type broad ion beam source. The nanotips have nanometre-size heads, micrometre-size roots and the same apex angle. All of the nanotips consistently point in the direction against the incident ion beam. The orientation of diamond nanotips can be controlled by adjusting the incident direction of the ion beam. The Raman spectrum does not show a significant increase in graphitic peak intensity after etching, indicating that the quality of diamond is barely degraded by ion beam etching. Near-edge x-ray absorption fine structure spectra show that the diamond sp3 structure is dominant in the spectra of both as-grown and ion etched diamond. The sp2 fraction is found to increase by about 12% at the surface layer of the diamond nanotips as compared with as-grown diamond. The formation of diamond nanotips is explained by Sigmund's sputtering theory and the angle-dependent sputtering mechanism. This method to produce diamond nanotips has the advantage of excellent orientation control and the capability to produce nanotip arrays on a large area.

In this paper, several new solutions of the evolution equation for Kelvin-Helmholtz waves near direct resonance are obtained by Darboux transformation.

Angle-resolved photoemission experiments have been carried out on Ag(111) in the photon energy range from 13 to 65 eV with both s- and sp-polarised synchrotron radiation. The valence band structure of Ag has been determined along the high-symmetry Lambda line by normal emission measurements. For photon energies smaller than 24 eV, the photoemission peaks could be interpreted as results of direct transitions between initial and final energy bands in the relativistic band structure calculated by Christensen (1972), and by Eckardt et al. (1984). For photon energies larger than 24 eV, the final band was obtained by fitting a free-electron-like final band (m*e=1.10, V0=-5.0 eV) to experimentally verified calculated symmetry points. The experimental valence bands deviate by about -0.3 eV from theory. Measured critical-point energies (in eV, band indices in parentheses) are: E( Gamma 8+(2,3))=-6.15+or-0.10, E( Gamma 7+(4))=-5.70+or-0.10, E( Gamma 8+(5,6))=-4.95+or-0.10, E(L6+(1))=-7.10+or-0.10, E(L4,5+(2))=-6.25+or-0.10, E(L6+(3))=-5.80+or-0.10, E(L6+(4))=-4.55+or-0.10 and E(L4,5+(5))=-4.30+or-0.10. A surface resonance was detected 4.2 eV below the Fermi level at the centre of the surface Brillouin zone Gamma , which has an origin similar to that of the surface resonances that have been observed on Cu(001) and Ag (001). A possible surface state is also reported at about 7.4 eV below the Fermi level at the Gamma point. The nature of this impurity-sensitive structure is not understood.