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Aluminum alloy is widely used in modern manufacturing industry but whose deformation when under certain regime of loading rates or temperature involves prominent Portevin–Le Chatelier (PLC) effect. In the present work the PLC effect in AA5052 aluminum alloy under different loading rates has been characterized via combined usage of digital image correlation (DIC) and acoustic emission (AE) techniques. Under the loading rates considered, different types of PLC bands have been found to yield distinct distribution of stress drops. The spatiotemporal evolution of the PLC bands at low loading rate may be accessible by both the DIC and AE techniques while those at high loading rates are accessible only by the AE technique. All the results may support that the PLC bands are nucleated rather than continuously propagating at high loading rates, which is in contrast to the conventionally held views. [ABSTRACT FROM AUTHOR]

Nonlinear effects can enrich the propagation of elastic waves in mechanical metamaterials, which makes it possible to extend classical phenomena and functions in linear systems to nonlinear ones. In this work, rather than monochromatic waves in similar linear structures, the negative refraction is realized by mixing waves which are generated in nonlinear elastic wave metamaterials. Based on the stiffness matrix and plane wave expansion methods, dispersion curves of in–plane modes resulting from the collinear and non–linear mixings of two longitudinal waves are calculated. In the frequency spectrum, two propagating modes coalesce at exceptional points due to the coupling of in–plane modes, and those points at which the refraction type changes are also exceptional ones. Two kinds of negative refraction can be found in the mixing modes near exceptional points, but each of them needs to be induced in a specific configuration. Moreover, experiments are performed to support the pure negative refraction and beam splitting of the nonlinear elastic waves. Particularly, the parallel configuration is able to separate and extract the nonlinear mode when the single–mode negative refraction occurs, which shows the possibility to design elastic wave device by the negative refraction of nonlinear mixing waves. [ABSTRACT FROM AUTHOR]

Due to the special ability of wave manipulation, elastic wave metamaterials have many interesting applications in mechanical engineering, vibration and sound isolation. This work proposes a movable metamaterial driven by nonlinear elastic waves with stop band and nonreciprocal crawling. Inspired by stop band properties, the metamaterial employs a periodic structure of nonlinear diatomic chain. A defect mass is introduced near the wave source to break the periodicity and symmetry, which leads to the nonreciprocal propagation of nonlinear elastic waves. With the asymmetric friction, the nonreciprocal and one-directional crawling of the metamaterial can be observed, which behaves as a movable mechanical diode. Furthermore, theoretical analysis is performed to derive the band structure and crawling velocity, which are supported by experiments. This research wishes to introduce nonlinear elastic wave metamaterials into new designs of robotics. [ABSTRACT FROM AUTHOR]

Mitochondria are the structures in cells that are responsible for producing energy. They contain a specific translation unit for synthesizing mitochondria-encoded respiratory chain components: the mitochondrial DNA (mt DNA). Recently, a growing number of syndromes associated with the dysfunction of mt DNA translation have been reported. However, the functions of these diseases still need to be precise and thus attract much attention. Mitochondrial tRNAs (mt tRNAs) are encoded by mt DNA; they are the primary cause of mitochondrial dysfunction and are associated with a wide range of pathologies. Previous research has shown the role of mt tRNAs in the epileptic mechanism. This review will focus on the function of mt tRNA and the role of mitochondrial aminoacyl-tRNA synthetase (mt aaRS) in order to summarize some common relevant mutant genes of mt aaRS that cause epilepsy and the specific symptoms of the disease they cause. [ABSTRACT FROM AUTHOR]

As a significant extension of classical structures, elastic wave metamaterials are widely applied to the vibration isolation and turning wave propagation. However, little attention has been paid on their fracture and arrest properties. In this work, the dispersion curves and arrest property of mode II crack in 2D elastic wave metamaterials are studied, in which both nonlocal interactions and local resonators are considered. Because every unit cell is connected to the second nearest neighboring one with the massless spring along the x-direction, the nonlocal interaction is achieved. The dynamic effective mass is derived and influences of nonlocal interactions on the dispersion relation are analyzed. Moreover, the energy release ratio which characterizes the arrest ability is derived and the effects of structural parameters are discussed. The theoretical predictions are also compared to the finite element simulation. Numerical results show that the crack propagation resistance of mode II crack can be improved significantly by introducing proper nonlocal springs within a finite steady-state region. But in the oscillation region, the energy release ratio G0/G is unstable. Furthermore, an additional energy barrier can be generated before the region in which the crack propagates stably. [ABSTRACT FROM AUTHOR]

This work studies about the band gap characteristics and nonreciprocal propagation of nonlinear elastic wave metamaterials which are composed of the curved particle chain with diatomic lattice. The incremental harmonic balance (IHB) method is applied to derive the nonlinear wave equation with fractional terms. Different curved angles and amplitude ratios are considered to show band gaps of nonlinear elastic waves. Both numerical calculations by the Runge-Kutta method and experiments are performed to support band gaps and diode behaviors. This study provides a new application of nonlinear phononic crystals and mechanical metamaterials with different curved directions. [ABSTRACT FROM AUTHOR]

Aims: Diabetic peripheral neuropathy (DPN) is a common diabetic complication. Aberrant mitochondrial function causes neurodegeneration under hyperglycemia-induced metabolic stress, which in turn results in DPN progression. m6A and m6A reader (YTHDC2) are closely related to diabetes and diabetes complications, while the role of YTHDC2 in regulating mitochondrial metabolism in DPN needs to be further probed. Methods: For HG treatment, Schwann cells (RSC96) were subjected to d-glucose for 72 h. db/db mice were used as the diabetic mouse model. Me-RIP assay was performed to evaluate KDM5B m6A level. RNA degradation assay was conducted to examine KDM5B mRNA stability. In addition, OCR and ECAR were examined by XF96 Analyzer. Moreover, the content of ATP and PDH activity in RSC96 cells were detected using kits, and the level of ROS was detected using MitoSOX staining. RIP, RNA pull-down and dual-luciferase reporter gene assays were carried out to verify the binding relationships between YTHDC2, KDM5B and SIRT3. Results: We first observed that KDM5B expression and KDM5B mRNA stabilization were significantly increased in DPN. The m6A reader YTHDC2 was lowly expressed in DPN. Meanwhile, YTHDC2 over expression decreased KDM5B mRNA stability in an m6A-dependent manner. Our results also revealed that YTHDC2 overexpression resulted in reduced ROS level and increased ATP level, PDH activity, OCR and ECAR in HG-treated Schwann cells, while these effects were reversed by KDM5B overexpression. Additionally, SIRT3 served as the target of YTHDC2/KDM5B axis in regulating mitochondrial metabolism in DPN. Conclusions: Taken together, YTHDC2 promoted SIRT3 expression by reducing the stabilization of KDM5B to improve mitochondrial metabolic reprogramming in DPN. [ABSTRACT FROM AUTHOR]

This investigation is focused on the nonreciprocal transmission of the non-collinear mixing wave in a nonlinear elastic wave metamaterial. The nonlinear elastic wave metamaterial with asymmetric structure is used to break the traditional reciprocal transmission, which is composed of a nonlinear material and a linear phononic crystal. When two non-collinear shear waves following the resonant condition interact with each other, the sum frequency longitudinal wave can be generated and propagate together with fundamental and second harmonics. Based on the transfer and stiffness matrices, band gaps and transmission coefficients are derived. The changing of band structures results in manipulating elastic waves with different frequencies. In the nonreciprocal frequency region, elastic waves can propagate along the positive direction while the reverse case is prohibited. The mixing of two incident SV waves in the nonlinear elastic wave metamaterial is verified by experiments and the results can support the theoretical analysis and numerical calculations. Because of material nonlinearity and asymmetric structure, the nonlinear elastic wave metamaterial can behave as a mechanical diode. The present work shows the possibility to design nonreciprocal elastic wave device by nonlinear wave mixing methods. [ABSTRACT FROM AUTHOR]

This article presents, for the first time, the kinetics and the general conversion features of a 3-component system, benzophenone–triphenylamine(BT)/iodonium/Amine, based on proposed mechanism of Liu et al., for both free radical polymerization (FRP) of acrylates and the free radical promoted cationic polymerization (CP) of epoxides using the new multi-functional initiator of BT. The additives, iodonium and amine, ethyl 4-(dimethylamino)benzoate (EDB), have the dual function of (i) regeneration BT and (ii) produce of extra radicals for improved FRP and CP. Analytic formulas are developed to explore the new features including: (i) the conversion efficacy (CE) of FRP is an increasing function of the light intensity, the effective absorption coefficient, and the concentration sum of each of the components, BT, Iod, amine, for transient state. However, CE at steady-state is independent to the light intensity; (ii) the trifunctional hybrid structures of BT3 leads to larger light absorption than other types of BT; it also provides more active sites for the H-abstraction in the presence of EDB, leading to high CE; (iii) the efficacy of FRP is an increasing function of the amine (EDB) concentration, in contrast to that of CP having an opposite dependence; (iv) the consumption rate of BT3 in the BT3/Iod/EDB system is slower than that of the BT3/Iod system due to photoredox catalytic cycle, and the larger initiator regeneration (RGE) in the three-component system. A comprehensive model is also proposed that the CE (for both FRP and CP) is governed by (NjKjbI), whereas more complex formulas are developed; where Kj is an effective rate constant proportional to the electron transfer quantum yield, and the combined effects of other coupling rate constants; b is an effective absorption coefficient given by the light absorption and excited state quantum yield. Measured data are analyzed by numerical simulation for the CE of FRP and CP, based on ten rate equations. [ABSTRACT FROM AUTHOR]

In this work, the head-on collision and transmission with nonreciprocal properties of opposite propagating solitary waves are studied, in which the interface between different granular chains is considered. Due to the discontinuity of two periodic granular systems, the transmitted and reflected solitary waves are produced. The head-on collision appears at the interface and the reductive perturbation method is applied to derive the generated solitary waves. According to the derivation and numerical simulation, we can find that the transmitted and reflected solitary waves can propagate with the same speed when they locate at the same chain. Moreover, the influences of both the arrangement and prestress are discussed. It is found that the amplitude and velocity of solitary waves become larger because of a bigger prestress, which result in the nonreciprocal collision and transmission in the granular mechanical metamaterials. This study is expected to be helpful for the design and application of elastic wave metamaterials and mechanical diodes with nonlinear solitary waves. [ABSTRACT FROM AUTHOR]

As emerging artificial structures, elastic wave metamaterials can show some unique properties in special frequency regions. In this study, the elastic wave scattering by a pair of parallel semi-infinite cracks in mechanical metamaterials with local resonators is studied. According to the discrete Wiener–Hopf method, the far field displacement solution is obtained. At the same time, the dynamic negative effective mass and band gaps can be observed with local resonators. Our attention is focused on how the internal microstructure affects the crack faces. Numerical results show that because of the stop band, the crack can be prevented from being disturbed by incident waves in specific frequency regions. As a result, the possibility of crack initiation and instability propagation is reduced considerably. This present work is expected to provide a way to improve arrest performance of elastic waves metamaterials. [ABSTRACT FROM AUTHOR]

Main conclusion: Key miRNAs including sbi-miR169p/q, sbi-miR171g/j, sbi-miR172a/c/d, sbi-miR172e, sbi-miR319a/b, sbi-miR396a/b, miR408, sbi-miR5384, sbi-miR5565e and nov_23 were identified to function in the regulation of Cd accumulation and tolerance. As an energy plant, sweet sorghum shows great potential in the phytoremediation of Cd-contaminated soils. However, few studies have focused on the regulatory roles of miRNAs and their targets under Cd stress. In this study, comparative analysis of sRNAs, degradome and transcriptomics was conducted in high-Cd accumulation (H18) and low-Cd accumulation (L69) genotypes of sweet sorghum. A total of 38 conserved and 23 novel miRNAs with differential expressions were identified under Cd stress or between H18 and L69, and 114 target genes of 41 miRNAs were validated. Furthermore, 25 miRNA–mRNA pairs exhibited negatively correlated expression profiles and sbi-miR172e together with its target might participate in the distinct Cd tolerance between H18 and L69 as well as sbi-miR172a/c/d. Additionally, two groups of them: miR169p/q-nov_23 and miR408 were focused through the co-expression analysis, which might be involved in Cd uptake and tolerance by regulating their targets associated with transmembrane transportation, cytoskeleton activity, cell wall construction and ROS (reactive oxygen species) homeostasis. Further experiments exhibited that cell wall components of H18 and L69 were different when exposed to cadmium, which might be regulated by miR169p/q, miR171g/j, miR319a/b, miR396a/b, miR5384 and miR5565e through their targets. Through this study, we aim to reveal the potential miRNAs involved in sweet sorghum in response to Cd stress and provide references for developing high-Cd accumulation or high Cd-resistant germplasm of sweet sorghum that can be used in phytoremediation. [ABSTRACT FROM AUTHOR]

Using the active feedback control system on the elastic wave metamaterial, this research concentrates on the sound transmission with the dynamic effective model. The metamaterial is subjected to an incident pressure and immersed in the external mean flow. The elastic wave metamaterial consists of double plates and the upper and lower four-link mechanisms are attached inside. The vertical resonator is attached by the active feedback control system and connected with two four-link mechanisms. Based on the dynamic equivalent method, the metamaterial is equivalent as a single-layer plate by the dynamic effective parameter. With the coupling between the fluid and structure, the expression of the sound transmission loss (STL) is derived. This research shows the influence of effective mass density on sound transmission properties, and the STL in both modes can be tuned by the acceleration and displacement feedback constants. In addition, the dynamic response and the STL are also changed obviously by different values of structural damping, incident angle (i.e., the elevation and azimuth angles) and Mach number of the external fluid with the mean flow property. The results for sound transmission by two methods are compared, i.e., the virtual work principle for double plates and the dynamic equivalent method corresponding to a single one. This paper is expected to be helpful for understanding the sound transmission properties of both pure single- and double-plate models. [ABSTRACT FROM AUTHOR]

Due to their potential properties unlike traditional materials and structures, elastic wave metamaterials have received significant interests in recent years. With the coupling between the acoustic and vibration, their mechanical characteristics can be tuned by the active feedback control system at low frequency ranges in which the traditional passive control is limited. This work illustrates that the superior performances of the effective mass density and sound pressure level (SPL) of an elastic wave metamaterial can be significantly changed by the active control, in which the periodic array of local resonators and orthogonal stiffeners are included. Significantly, based on the locally resonant mechanism, the negative density occurs over a frequency range. Due to the effects of lattice constant, structural damping and other parameters, the SPL with the function of fluid–solid coupling are illustrated and discussed. [ABSTRACT FROM AUTHOR]

In this study, the dynamic effective parameters and crack arrest behavior of locally resonant metamaterials with multiple degrees of freedom are investigated. Based on the Wiener-Hopf method, the energy release ratio which characterizes the crack splitting resistance is derived, and the influences of the material parameters are discussed. In comparison with the monoatomic lattice chain and locally resonant metamaterials composed of unit cells with a single degree of freedom, this new periodic structure with coupling multiple degrees of freedom displays some essential features during the crack propagation. The results show that due to the coupling of different displacements, the crack dynamic growth in the elastic wave metamaterials exhibit a lower energy release ratio, which indicates a better fracture resistance and arrest property. The present work can be expected to provide a way to improve the ability to resist crack propagation of advanced materials and structures. [ABSTRACT FROM AUTHOR]

The topology concept in the condensed physics and acoustics is introduced into the elastic wave metamaterial plate, which can show the topological property of the flexural wave. The elastic wave metamaterial plate consists of the hexagonal array which is connected by the piezoelectric shunting circuits. The Dirac point is found by adjusting the size of the unit cell and numerical simulations are illustrated to show the topological immunity. Then the closing and breaking of the Dirac point can be generated by the negative capacitance circuits. These investigations denote that the topological immunity can be achieved for flexural wave in mechanical metamaterial plate. The experiments with the active control action are finally carried out to support the numerical design. [ABSTRACT FROM AUTHOR]

Although gemcitabine, oxaliplatin and L-asparaginase/pegylated asparaginase (P-GEMOX) treatment for early-stage extranodal natural killer/T cell lymphoma (ENKTL) is effective, some patients die within 1 year of diagnosis. We attempted to determine an optimal biomarker for identifying such patients. We enrolled 71 patients with ENKTL who received P-GEMOX between January 2011 and January 2014. We classified the patients according to the outcome into worse (died within 1 year) or better groups (survival time ≥ 3, 4 or 5 years). The area under the curve (AUC) was determined to identify the optimal biomarker for differentiating the groups. The AUC was highest in patients who were plasma Epstein-Barr virus (EBV) DNA-positive post-treatment. The AUC was 0.82, 0.86 and 0.86 when the worse group was compared to the better group, respectively. Among the post-treatment EBV DNA-positive patients, as compared to EBV DNA-negative patients, pre-treatment EBV DNA-positive patients had a higher proportion of CD4 + CD25 + T cells. There was higher programmed cell death protein ligand-1(PD-L1) expression in post-treatment EBV DNA-positive patients. Post-treatment positive EBV DNA status maybe a useful biomarker of worse outcomes in early stage ENKTL. [ABSTRACT FROM AUTHOR]

Numerical simulation of resistivity logging-while-drilling (LWD) tool response in complex borehole environments is of great importance for interpretation of measurement data and characterization of oil reservoirs. The simulation results can provide important theoretical guidance for designing novel electrical logging instruments and interpreting real-time logging data. In this paper, higher-order vector finite element method had been used to investigate the resistivity LWD tool response by changing coils spacing, transmitting frequency and structure of antenna system in the anisotropic formation. Numerical simulation results indicate that the change of T- R spacing is an obvious influence on the investigation depth and detecting precision of the resistivity LWD tool, and the change of R - R spacing can affect the resolution of the thin-layer distinguish. The change of transmitting frequency can improve the resolution of low-resistivity formation and high-resistivity formation of resistivity LWD tool. The change of the structure of the antenna system can provide accurate geosteering drilling information to directional resistivity LWD tool. Simulation results also indicated that the higher-order vector finite element method has good convergence speed and calculation accuracy and it is suitable to simulate the response of resistivity LWD tools. [ABSTRACT FROM AUTHOR]

The homoclinic phenomena in double-layered nanoplates (DLNP) are investigated. Based on the nonlocal continuum theory, the nonlinear dynamical equations for DLNP subjected to in-plane excitation are derived by double-mode Galerkin truncation. The extended Melnikov method is utilized to discuss the homoclinic phenomena and chaotic motion for the buckled DLNP system. The criterions for the existence of transverse homoclinic orbits are established under different four buckling cases (i.e., the first- and second-type synchronous buckling as well as asynchronous buckling). And the results derived by the above-mentioned analysis are verified by molecular dynamics and Lyapunov exponent spectrum. Small-scale effect on the homoclinic motion is mainly inspected. From the result, it is rather novel that the transversality condition is independent of the nonlinear terms in the equations. This fact means that it is not necessary to distinguish whether the boundaries are movable or immovable for the in-plane parametric excitation DLNP. The parametric regime where homoclinic phenomena appear shrinks with the augment of nonlocal parameter for the first-type synchronous buckling case. However, this trend is just opposite for the other three buckling cases. Finally, it can be seen that homoclinic phenomena more likely occur on Mode I (i.e., lower mode) for the second-type synchronous and asynchronous buckling cases. However, the homoclinic motion for the first-type asynchronous buckling most likely takes place on Mode III. [ABSTRACT FROM AUTHOR]

Different from the linear thermal buckling of carbon nanotubes with small deformation, nonlinear postbuckling induced by the temperature change can present more applicable result because of the postbuckling after the linear status. In this investigation, the nonlinear postbuckling of double-walled carbon nanotubes is studied by the nonlocal continuum model. The nonlinear large deformation is taken into account, and the thermal effects are considered. The explicit solution for the critical temperature is derived, which has the relation to the transverse deflection. From the numerical results, it can be observed that different from the linear thermal buckling, the normalized critical temperature for the nonlinear postbuckling depends on the deflection of the nanotubes and can bear more thermal loads. The small-scale effects can be enhanced by the large mode numbers, and the small-scale effects on the nonlinear postbuckling properties are significant for the short nanotubes. Moreover, the nonlinear postbuckling behaviors of short carbon nanotubes are more sensitive to the maximum deflection and mode number. [ABSTRACT FROM AUTHOR]

In this study, a rigid line inclusion on the interface between two dissimilar thermo-electro-magneto-elastic solids is considered. Based on the Muskhelishvili's theory and extended Stroh formalism, it is reduced to the non-homogeneous Hilbert equation. According to the holomorphic continuation technology and Muskhelishvili's theory, the exact solutions for both thermal and electro-magneto-elastic fields are derived. The explicit expressions of the multiple coupling fields are presented, and the generalized stress intensity factors are illustrated with the closed form. From the results, it can be observed the coupling of the thermo-electro-magneto-elastic effects. Moreover, the generalized stress has singularities and oscillatory properties near the inclusion tip. [ABSTRACT FROM AUTHOR]

In the present work, the effective material properties of thermoelectric composites with elliptical fibers are studied. Explicit solutions are derived by the conformal mapping function and Mori-Tanaka method. Numerical simulations are performed to present the behaviors of normalized effective material constants. From the results, it can be observed that both the effective electric and thermal conductivities can be reduced by increasing the filling ratio and a/ b. Such influences can also be found for the effective thermoelectric figure of merit. But they are different from those on the effective Seebeck and Peltier coefficients. [ABSTRACT FROM AUTHOR]

In this paper, vibration band gap properties of periodic Mindlin plate structure with two simply supported opposite edges are studied using the spectral element method (SEM). Based on the Mindlin plate theory (MPT), the spectral Mindlin plate stiffness matrix is deduced. The spectral equation of the whole periodic structure is further established. Frequency responses are calculated by the spectral equations to illustrate band gap properties. Compared with the results based on the classic plate theory (CPT), the effects of the shear and rotary inertia on the band gap properties are analyzed. The results are also compared with those calculated by the finite element method (FEM). It can be observed that the SEM is more accurate in high frequency ranges. Furthermore, the influences of the material properties and structure dimension on the band gap behaviors are investigated. [ABSTRACT FROM AUTHOR]

In this paper, thermal buckling properties of a nanoplate with small-scale effects are studied. Based on the nonlocal continuum theory, critical temperatures for the nonlocal Kirchhoff and Mindlin plate theories are derived. The thermal buckling characteristics are presented with different models. The influences of the scale coefficients, half-wave numbers, width ratios, and the ratios of the width to the thickness are discussed. From this work, it can be observed that the small-scale effects are significant for the thermal buckling properties. Both the half-wave number and width ratio have influence. The nonlocal Kirchhoff plate theory is valid for the thin nanoplate, and the nonlocal Mindlin plate theory is more appropriate for simulating the mechanical behaviors of the thick nanoplate. [ABSTRACT FROM AUTHOR]

Periodic structures have great scientific potential because of their superior structural dynamic properties. The aim of this study is to analyze the dynamic behavior of periodic plate structures using the spectral element method (SEM). The spectral equations of the plate elements with two parallel sides that are simply supported are established. Then, the spectral dynamic stiffness matrix of the whole periodic plate structure is assembled. The frequency responses are obtained by the calculation of the spectral equations to illustrate the characteristics of the band gaps. From the results, it is seen that the SEM can be effectively applied to study the vibration properties of the periodic structures. Compared with the results calculated by the finite element method, it can be observed that more accurate results in high-frequency ranges can be achieved by the SEM. These results indicate that the band gap characteristics depend on both the material properties and unit cell numbers. Furthermore, the effects of the structure damping and type on the frequency responses are investigated. [ABSTRACT FROM AUTHOR]

In this paper, the small-scale effects on the flexural wave in the nanoplate are studied. Based on the nonlocal continuum theory, the equation of wave motion is derived and the dispersion relation is presented. Numerical simulations are performed to investigate the influences of the scale coefficient, the surrounding elastic matrix and the initial stress on the wave propagation properties. The results show that the nonlocal model provides an appropriate method to investigate the characteristics of the flexural wave in the nanoplate. Furthermore, the direction and amplitude of the biaxial load, the stiffness of the shearing layer and the Winkler foundation can change the wave properties, significantly. [ABSTRACT FROM AUTHOR]

In this paper, the propagation and localization of elastic waves in randomly disordered layered three-component phononic crystals with thermal effects are studied. The transfer matrix is obtained by applying the continuity conditions between three consecutive sub-cells. Based on the transfer matrix method and Bloch theory, the expressions of the localization factor and dispersion relation are presented. The relation between the localization factors and dispersion curves is discussed. Numerical simulations are performed to investigate the influences of the incident angle on band structures of ordered phononic crystals. For the randomly disordered ones, disorders of structural thickness ratios and Lamé constants are considered. The incident angles, disorder degrees, thickness ratios, Lamé constants and temperature changes have prominent effects on wave localization phenomena in three-component systems. Furthermore, it can be observed that stopbands locate in very low-frequency regions. The localization factor is an effective way to investigate randomly disordered phononic crystals in which the band structure cannot be described. [ABSTRACT FROM AUTHOR]

Propagation of elastic waves along a direction has special interests in practical applications. These concerns generate the design of an elastic wave metamaterial with electrically switchable properties, which is studied in this work. The structure contains a T-shaped waveguide in a plate with the 3D printing technology; and the active control system is used to tune the propagation direction of the flexural wave. The piezoelectric patches which are connected by the negative capacitance circuits are applied to behave as the active control system. The finite element simulation is performed to give the theoretical prediction of the switchable waveguide and the tunable equivalent parameters are achieved by the electrical circuits. The active control experiments are finally carried out to support the numerical design. [ABSTRACT FROM AUTHOR]