In this paper, we discuss orientations given to edges of Eulerian graphs embedded on closed surfaces, and give a characterization of such a graph having a good orientation, i.e., incoming edges and ...outgoing edges appear alternately around each vertex of the graph. Furthermore, we consider the partially broken orientations of Eulerian graphs embedded on closed surfaces, that is, one in which only for each of specified vertices, incoming edges and outgoing edges appear alternately around it. We discuss a little about good orientations defined for Eulerian graphs drawn on closed surfaces with crossings, and for general connected graphs, i.e., not necessarily Eulerian graphs, embedded on closed surfaces.
An SiO2-TiO2 closed-surface antireflective coating was fabricated by the one-dipping method. TiO2 nanoparticles were mixed with a nanocomposited silica sol, which was composed of acid-catalyzed ...nanosilica networks and silica hollow nanospheres (HNs). The microstructure of the sol-gel was characterized by transmission electron microscopy. The silica HNs were approximately 40–50 nm in diameter with a shell thickness of approximately 8–10 nm. The branched-chain structure resulting from acidic hydrolysis grew on these silica HNs, and TiO2 was distributed inside this network. The surface morphology of the coating was measured by field emission scanning electron microscopy and atomic force microscopy. After optimization, transmittance of up to 94.03% was obtained on photovoltaic (PV) glass with a single side coated by this antireflective coating, whose refractive index was around 1.30. The short-circuit current gain of PV module was around 2.14–2.32%, as shown by the current-voltage (IV) curve measurements and external quantum efficiency (EQE) tests. This thin film also exhibited high photocatalytic activity. Due to the lack of voids on its surface, the antireflective coating in this study possessed excellent long-term reliability and robustness in both high-moisture and high-temperature environments. Combined with its self-cleaning function, this antireflective coating has great potential to be implemented in windows and photovoltaic modules.
•A laser-based nonlinear ultrasonic method is used to detect closed surface crack.•Nonlinear interaction is simulated by a numerical model and verified by experiment.•Remote and coupling-free ...measurement of closed surface crack.
Nonlinear ultrasonic testing method is one of few techniques that are effective for evaluating early material degradation and micro-crack initiation by analysing the nonlinear effects of ultrasonic waves. This study presents a noncontact nonlinear ultrasonic testing method based on lasers for closed surface crack inspection. A pulsed laser grating source by grating mask is applied to generate narrowband surface acoustic wave of a chosen frequency. A nonlinear numerical simulation based on Finite Element Method (FEM) is developed to simulate the generation of higher harmonics by closed surface crack. The simulation results show that the acoustic nonlinearity parameter increases with the micro closed crack length, while decreases with the micro closed crack buried depth. Moreover, the detection capability of this method is verified by an experiment. The experimental results show that the proposed laser-based nonlinear ultrasonic testing method can provide a fully noncontact and coupling-free measurement method for closed surface crack inspection.
•CS-AR SiO2-TiO2 films were prepared by doctor-blade method.•The obtained CS-AR films are titanium oxide crystals in amorphous silicon oxide.•Optical property of glass was enhanced significantly by ...coating CS-AR SiO2-TiO2 films.•The transmittance was increased from 90.2 (bare glass) to 96.8% (CS-AR coated glass).•The CS-AR SiO2-TiO2 films are anti-fog and anti-fouling.
This paper reports the characteristics of closed-surface antireflective TiO2–SiO2 nanocomposite (CS-AR) films. The films were designed with two layers: a porous layer at the bottom and a dense one at the top. Both layers were fabricated through a printing method combined with an annealing process. The thickness of both layers ranged within 106–118 nm. The phase structure of the films was a nanocomposite of titanium and silicon dioxides. TiO2 is highly crystalline and SiO2 is amorphous, so the transmittance of the glass was significantly enhanced after coating the CS-AR film on the surface. Transmittance increased from 90.2 % (bare glass) to 96.8 % (CS-AR-coated glass). The CS-AR films also showed a high hydrophilic antifog property.
The study of the mapping class group Mod(S) is a classical topic that is experiencing a renaissance. It lies at the juncture of geometry, topology, and group theory. This book explains as many ...important theorems, examples, and techniques as possible, quickly and directly, while at the same time giving full details and keeping the text nearly self-contained. The book is suitable for graduate students.
Conventional electric field integral equation-based theory is susceptible to the spurious internal resonance problem when the characteristic modes (CMs) of closed perfectly conducting objects are ...computed iteratively. In this paper, we present a combined field integral equation-based theory to remove the difficulty of internal resonances in CMs analysis. The electric and magnetic field integral operators are shown to share a common set of nontrivial characteristic pairs (values and modes), leading to a generalized eigenvalue problem which is immune to the internal resonance corruption. Numerical results are presented to validate the proposed formulation. This work may offer efficient solutions to CM analysis which involves electrically large closed surfaces.
Abstract We consider the numerical approximation of Gaussian random fields on closed surfaces defined as the solution to a fractional stochastic partial differential equation (SPDE) with additive ...white noise. The SPDE involves two parameters controlling the smoothness and the correlation length of the Gaussian random field. The proposed numerical method relies on the Balakrishnan integral representation of the solution and does not require the approximation of eigenpairs. Rather, it consists of a sinc quadrature coupled with a standard surface finite element method. We provide a complete error analysis of the method and illustrate its performances in several numerical experiments.
The main drawbacks of aerated concrete preparation traditional technology are considered. The method essence for the porous structure formation of aerated concrete products with variational ...properties is formulated. The main factors affecting aerated concrete products properties of varying density and strength along the cross-section are indicated. The mold cover closed surface with a circular opening area effect on aerated concrete products main properties is shown and its optimum value is revealed. The traditional and modern types gas generators influence on gas evolution kinetics, mixture swelling height, gas generators stability in time and variable density and strength on the cross-section aerated concrete products main properties are considered.
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