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Furan-based derivatives are promising biomass fuels that may be used directly in internal combustion engines as alternative fuels or as additives to fossil fuels. In this work, the experimental studies of 2-acetylfuran (AF2) pyrolysis were carried out in a jet-stirred reactor in the temperature range of 770 – 1130 K and at the pressure of 760 Torr, using synchrotron vacuum ultraviolet photo-ionization mass spectrometry, coupled with gas chromatography. Key pyrolysis intermediates such as methane, ethylene, acetylene, ketene, vinylacetylene, cyclopentadiene, ethynylketene, 2-methylfuran, furfural, carbon monoxide and isomers such as allene/propyne, furan/vinylketene, benzene/fulvene, etc., were identified and quantified. The potential energy surfaces of AF2 unimolecular decomposition reactions were calculated at CBS-QB3 level. The temperature- and pressure-dependent rate constants of the relevant reactions were calculated by solving the master equation based on Rice-Ramsperger-Kassel-Marcus theory. A detailed pyrolysis kinetics of AF2 was developed based on the previous combustion models of 2-methylfuran and was validated against the current experimental results. Rate of production and sensitivity analysis showed that the main consumption pathways of AF2 pyrolysis under atmospheric pressure are unimolecular decomposition reactions, leading to 2-furyl + acetyl and furoyl + methyl, and hydrogen atom-addition reaction to C(5), leading to 2,3-dihydro-5-acetyl-3-furyl, accounting at 1070 K for 25.1%, 13.2% and 20.7% of AF2 consumption, respectively (the remaining 41.0% are due to minor reaction channels contributing

This paper is dedicated to investigating the problem of an infinite one-dimensional hexagonal quasi-crystal medium weakened by a penny-shaped crack and subjected to a pair of anti-symmetric and identical uniform heat fluxes. In view of the anti-symmetry with respect to the crack plane, this problem is formulated by a mixed boundary value problem of the half-space. Based on the general thermo-elastic solution, the mixed boundary value problem is solved by means of the generalized potential theory method. The thermo-elastic field variables in the entire three-dimensional space are explicitly expressed in terms of elementary functions. Some important physical quantities on the crack plane, e.g., temperature, crack slip displacement, shear stress and stress intensity factor, are also presented in closed-forms. Numerical calculations are carried out to validate the present analytical solution and to graphically show the distribution of the thermo-elastic coupling field around the crack. The present solution may be served as a benchmark for the experimental investigations by infrared-thermography technique.

Although graphitic carbon nitride (g-C3N4, CN) has been widely studied for its photocatalytic applications in environmental remediation and solar energy conversion, the electronic structure of CN has not been optimized in terms of reactant activation and ROS generation. In this work, C self-doped g-C3N4 (CN-C) was prepared by co-pyrolysis of urea and saccharose and showed highly enhanced photocatalytic NO removal efficiency in comparison with the pristine CN. Theoretical and experimental methods were highly combined to illustrate the geometric structures of CN-C and reveal the promotion mechanisms in terms of enhanced optical and electron transfer properties. The unique electronic structure of CN-C allows NO and O2 to be more easily activated for the production of reactive radicals to participate in the photocatalytic redox reaction. The enhanced production of reactive radicals and the boosted separation rate of photogenerated carriers could promote the photocatalysis efficiency, leading to efficient and stable photocatalytic oxidation of NO over C self-doped g-C3N4. Importantly, the conversion pathways of photocatalytic NO oxidation over CN and CN-C have been elucidated based on the results of DFT calculations, ESR spectra and in situ DRIFTS spectra. A new absorption band at 2175 cm−1 associated with the NO+ intermediate is discovered for CN-C. The present work could offer new insights into the understanding of the electronic structure and photocatalytic NO oxidation mechanism on typical photocatalysts.

This article designs an active/semi-active hybrid isolator using magnetorheological elastomer isolator and piezoelectric stack actuator to suppress the wide-frequency vibration in precision platform, which can be switched to active isolator, semi-active one, and passive one according to the spectrum signature of the excitation. First, the structure of the hybrid isolator is introduced. Then, the dynamic model of the hybrid isolation system is established, the model parameters are identified, and the switching condition for the hybrid isolator is derived by experiments. Next, considering variable amplitude and frequency vibration of the isolated system, an active and semi-active fuzzy switch controller is designed for piezoelectric stack actuator and magnetorheological elastomer hybrid isolator, which are independent of the system model, self-tuning, and robust. Finally, the numerical simulations are conducted under variable frequency excitations to evaluate the performance of the designed fuzzy switch controller, and the results show that the hybrid isolator, combined with the fuzzy switch controller, can attenuate full frequency vibration effectively.

This paper investigates the problem of an infinite multiferroic composite medium weakened by a penny-shaped crack, which is symmetrically subjected to four pairs of generalized loads on the upper and lower surfaces. These loads could be mechanical pressures, electric displacements, magnetic inductions and temperature increments. In view of the magneto-electric properties of the crack surfaces, four mixed boundary problems are formulated. Based on the general solution, the three-dimensional thermo-magneto-electro-elastic coupling field variables in the three-dimensional full space for various boundary cases are explicitly obtained by means of the generalized potential theory method. Some important physical quantities in fracture mechanics, such as the generalized stress intensity factors and the generalized crack surface displacements, are presented as well. Numerical calculations are performed to validate the present solutions and to show the distributions of the 3D coupled fields. The influences of the magneto-electric properties of the crack surfaces on the generalized stresses and stress intensity factors are revealed.

In the present paper, the electric polarization saturation at the front of a thermally loaded penny-shaped crack in an infinite thermo-piezo-elastic medium is studied in both analytical and numerical manners. This crack is assumed to be electrically semi-permeable, and the electric field in the crack cavity is taken into account. An approximate analytical solution to the present non-linear crack problem is derived on the basis of the electric polarization saturation model together with the fundamental solutions for two concentrated loading crack problems. Further, the refined crack surface displacement, crack surface electric potential and electric displacement outside the crack are also presented in closed-forms. The validity of the analytical solution is checked via the numerical discrete method together with an iterative approach. A good agreement is observed. The influences of some material constants on the electric yielding zone are numerically revealed. An empirical formula is developed for the extent of electric yielding zone at the crack tip. In view of the wide applications of piezoelectric ceramics in various thermal environments, the present analysis could serve as a reference for the design of various smart structures of piezoelectric media.

In the present work, a penny-shaped/half-infinite plane crack problem is investigated in the framework of thermo-elasticity of two-dimensional quasi-crystals. In view of the symmetry with respect to the crack plane, the original problem is formulated by a mixed boundary-value problem defined in a half-space. The boundary integral equations are derived by virtue of the general solution and the method of generalized potential theory. For the crack subjected to a pair of point temperature loadings, the corresponding fundamental thermo-elastic field variables are exactly and explicitly obtained in terms of elementary functions. Furthermore, the physical quantities on the crack plane, which are important in fracture mechanics, are given. Numerical calculations are carried out to discuss the validity of the present solutions and to characterize the thermo-phonon-phason coupling effect. The present analytical solutions may serve as benchmarks for future computational fracture mechanics of QCs and as a guide for the infrared thermography techniques in non-destructive detection.

The accurate high-frequency modeling and average power handling capability (APHC) evaluation of doped multilayer graphene nanoribbon (GNR) interconnects are investigated in this paper. Based on the Boltzmann equation, both the normal skin effect (NSE) and anomalous skin effect (ASE) of GNRs in the high-frequency range are analyzed and compared. With the extracted electrical parameters, the APHC of GNR interconnects is predicted in a wide frequency range. The impact of ASE on APHC is illustrated for on-chip interconnect applications. Numerical examples show that the temperature rise will be seriously underestimated if the ASE is ignored in the high-frequency modeling.

Magnetorheological elastomers (MREs) are a kind of smart material, whose mechanical properties are controllable with applied magnetic field. Moreover, there is a greater magnetorheological effect for MREs at small strain amplitude, which has attracted more attention in the field of microvibration control. In this paper, an MRE isolator with shear-compression mixed mode was developed to suppress the high-frequency and microamplitude vibration of a precision-fabrication platform. To evaluate and characterize the dynamic behavior of the MRE isolator, experiments were conducted under harmonic load and different magnetic fields, respectively. Experiments showed that the resonance frequency of the MRE isolation system shifted from 45.82 (0 A) to 82.55 Hz (1.5 A). Meanwhile, the relative change in equivalent stiffness and damping was 175% and 216%, respectively, and the relative change in isolator force was 190% from 0 to 1.5 A. The proposed mixed mode MRE isolator effectively isolated vibration at high frequency for microamplitude.

This paper deals with the problem of an infinite isotropic solid weakened by a penny-shaped crack, which is subjected to a pair of uniform heat flux loadings symmetrically exerted on the upper and lower crack surfaces. Three-dimensional thermo-elastic field variables are obtained by means of potential theory method in company with the newly developed general solution. Some physical quantities on the cracked plane, such as temperature, radial displacement, crack surface displacement, normal stress at the crack front and stress intensity factor, which are important parameters in fracture mechanics, are presented in closed-forms. In the framework of ideal thermo-elasto-plasticity, the extent of the plastic zone at the crack front is determined by the Dugdale crack model, which linearizes the original non-linear problem. The refined crack surface displacement and normal stress outside the crack are also obtained via the principle of superposition. Numerical calculations are carried out to validate the present solutions and to show the distributions of the axisymmetric thermo-mechanical fields. The present solution could be served as a reference for the infrared-thermography technique.

With the application of innovative anchor concepts and advanced technologies in deepwater moorings, anchor behaviors in the seabed are becoming more complicated and significantly affected by the anchor line. Based on the coupled Eulerian–Lagrangian (CEL) method, a numerical approach incorporating anchor line effects is developed to investigate comprehensive anchor behaviors in the soil, including penetration of drag anchors, keying of suction embedded plate anchors and diving of gravity installed anchors. Compared to the method directly incorporating the anchor line into the CEL analysis, the proposed method is computationally efficient. To examine the robustness and accuracy of the proposed method, numerical probe tests and then comparative studies are carried out. It is found that the penetration (or diving) and keying behaviors of anchors can be well simulated. A parametric study is also undertaken to quantify the effects of various factors on the behavior of OMNI-Max anchors, whose mechanisms are not yet fully understood. The maximum embedment loss of OMNI-Max anchors during keying is not influenced by the initial anchor embedment depth, whereas significantly increases with increasing drag angle at the embedment point. With decreasing initial anchor embedment depth or increasing soil strength gradient, drag angle at the embedment point and diameter of the anchor line, the behavior of OMNI-Max anchors could change from diving to pullout, which is undesirable in offshore engineering practice. If the drag angle increases over a certain limit, the anchor will fail similar to a suction anchor.

The rapid increase in the demand for propylene and its derivatives requires urgently developing propylene-producing technology. To better understand the complicated reactions on W-based metathesis catalyst for propylene production and further to clarify the involved reaction mechanism, thermodynamic calculation was first performed to analyze the gas mixture under different conditions theoretically. The analyzed reaction system is close to the ideal gas under typical reaction conditions. The detailed investigation of reactions under different conditions was then carried out using WO 3 /SiO 2 and MgO catalysts in a fixed-bed tubular micro reactor. Experimental results together with calculation demonstrate that temperature plays the most important role in regulating metathesis reaction compared with other factors such as pressure, ethylene content and weight hourly space velocity (WHSV). Also, ethylene content in the feedstock affects a lot on metathesis process. With an optimized ratio of ethylene/ n -butene, cross-metathesis of 2-butene and ethylene is more likely to take place than that of 1-butene and 2-butene, and trans -2-butene has a generally better activity to react with ethylene than cis -2-butene due to the steric effect. On the other hand, isomerization is more independent on temperature compared with metathesis reaction. The consumption of 2-butene in metathesis will promote isomerization of 1-butene to 2-butene. Some extreme conditions such as higher pressures, larger ethylene contents and lower temperatures will provide opportunities for polymerization of ethylene. Based on the reaction analysis under different conditions, the reaction routes are summarized and a supposing mechanism for the formation of metallacyclobutane intermediate from trans / cis -2-butene is proposed.

This paper aims to analytically study the three-dimensional steady-state thermo-elastic field in an infinite space containing a penny-shaped crack subjected to a set of temperature loadings. The material is assumed to be isotropic and the loadings are symmetrically applied on the crack surfaces. In view of the symmetry with respect to the cracked plane, the present crack problem is formulated as a mixed boundary-value problem. The corresponding boundary integral and integro-differential equations are solved by virtue of the potential theory method in conjunction with the newly developed general solution. For the crack subjected to point or uniform temperature loadings, the thermo-elastic field variables are explicitly and exactly obtained in terms of elementary functions, in a complete manner. In both non-axisymmetric and axisymmetric cases, some important parameters in fracture mechanics, e.g., the crack surface displacement, the normal stress in the intact subregion of the crack plane and the stress intensity factor are explicitly derived as well. The validity of the present solutions is discussed analytically and by virtue of finite element simulation. The obtained analytical results can be combined with experimental investigations by the infrared-thermography technique.

This paper develops a closed-form analytical solution for the problem of an infinite transversely isotropic thermoporoelastic rock weakened by an elliptic crack lying in the transverse plane. The crack is symmetrically subjected to three pairs of uniform generalized loads, i.e., mechanical pressure, pore pressure and temperature increment, on the upper and lower crack surfaces. Based on the general solution, the three-dimensional (3D) steady-state thermoporoelastic field in the rock are explicitly derived in terms of elemental functions and elliptic integrals by the generalized potential theory method. The crack surface displacements, crack stiffness, normal stress in the cracked plane, and stress intensity factor at the crack tip are obtained as well. In the numerical calculation, the obtained analytical solution is first degenerated into the one for a circular crack for the purpose of verification, and then used to demonstrate the thermoporoelastic field around an elliptic crack and its geometric effect on the stress intensity factor at its tips. The present solution can serve as a convenient benchmark to various numerical codes for simulations of rock fracture.

The tensile behavior of single crystal superalloys CMSX-4 was investigated under different strain rates at room temperature. The objective of this study is to identify the strain rate sensitivity and understand the damage failure mechanism by checking stress-strain curves and microstructure of the deformed sample. Experimental results show that the stress-strain curves including strain hardening behavior at both strain rates are different. The size of cleavage facets and dimples in the tensile fracture surface is related to the strain rates. The shearing lines cross through the γ matrix and γ' precipitates, which is related to the movement of dislocations. Then, Schmid factor and the damage failure mechanism during tensile tests are estimated and discussed.

The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer’s (LR) solution for liver perfusion and preservationin vitroor combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic geneBcl-2and decreasing the expression of the proapoptosis genes ofCaspase-3andBax, and further protects hepatocytes from apoptotic death and improves liver function.

The present paper is devoted to determining the crack tip plasticity of a half-infinite Dugdale crack embedded in an infinite space of one-dimensional hexagonal quasicrystal. A pair of equal but opposite line loadings is assumed to be exerted on the upper and lower crack lips. By applying the Dugdale hypothesis together with the elastic results for a half-infinite crack, the extent of the plastic zone in the crack front is estimated. The normal stress outside the enlarged crack and crack surface displacements are explicitly presented, via the principle of superposition. The validity of the present solutions is discussed analytically by examining the overall equilibrium of the half-space.

The present work is concerned with a penny-shaped Dugdale crack embedded in an infinite space of one-dimensional (1D) hexagonal quasicrystals and subjected to two identical axisymmetric temperature loadings on the upper and lower crack surfaces. Applying Dugdale hypothesis to thermo-elastic results, the extent of the plastic zone at the crack tip is determined. The normal stress outside the plastic zone and crack surface displacement are derived in terms of special functions. For a uniform loading case, the corresponding results are presented by simplifying the preceding results. Numerical calculations are carried out to show the influence of some parameters.

A well-defined heterogeneous palladium catalyst, graphene oxide grafted with PdCl 2 , was prepared and found to be an effective catalyst for the C–C, C–N coupling of hetero aryl sulfonates with aryl boronic acids, terminal alkynes, amines, respectively, leading to the desired coupling products in moderate to excellent yields. The catalyst was characterized by XRD, IR, SEM, TEM, XPS and ICP. It is worthy noting that this catalyst offers a number of advantages such as high stability and negligible metal leaching. It also retains good activity for at least five successive runs without any additional activation treatment, showing a better performance than the well-known commercial Pd/C catalysts. This approach would be very useful from a practical viewpoint.

Adenosine triphosphatase inhibitory factor 1 (IF1) has previously been considered to be a driving oncogene in human cancers. Several studies have revealed that IF1 overexpression is present in a variety of tumor types and promotes tumor growth and metastasis. The present study aimed to investigate the clinical significance of IF1 in glioma and the role of IF1 in cell migration and invasion. The mRNA and protein expression of IF1 in glioma tissues was found to be significantly increased compared with the expression in normal brain tissues (P

In order to address the fast charge recombination of pristine g-C3N4, easily available composite precursors such as dicyandiamide (melamine) and urea were used and thermally treated in situ creating type I and type II g-C3N4/g-C3N4 metal-free isotype heterostructures. The construction of these heterostructures was based on different band-alignment patterns (staggered and straddled band alignments). The confirmation of isotype g-C3N4/g-C3N4 heterostructures was based on X-ray diffraction, photoluminescence, transmission electron microscopy, and valence band X-ray photoelectron spectroscopy. For g-C3N4/g-C3N4 heterostructures from dicyandiamide and urea (type II, staggered band alignments) under visible light, the photogenerated electrons in the conduction band of CN-D (g-C3N4 from dicyandiamide) could transfer to the conduction band of CN-U (g-C3N4 from urea) driven by an offset of 0.04 eV, whereas the photogenerated holes could transfer from CN-U to CN-D driven by a valence band offset of 0.36 eV, thus photogenerated electrons and holes could be separated effectively. For g-C3N4/g-C3N4 heterostructures from melamine and urea (type I, straddled band alignments), the photo-induced electrons could transfer from CN-U to CN-M (g-C3N4 from melamine) driven by a conduction band offset of 0.17 eV, while photogenerated holes could not be transported from one side to another side, also promoting the separation of photo-induced electrons and holes. The intrinsic drawback of fast charge recombination of pristine g-C3N4 was overcome by formation of type I and type II g-C3N4/g-C3N4 heterostructures. For the removal of ppb-level NO in air, the type I and type II g-C3N4 based heterostructures demonstrated highly enhanced photocatalytic activity and stability in comparison with g-C3N4 alone, which could be directly ascribed to the promoted charge separation. The rational design and construction of type I and type II isotype heterojunctions was general and powerful for the development of efficient visible-light photocatalysts with potential large scale environmental and energetic applications. The present work could also enrich new types of visible-light heterostructured photocatalysts, which may find wide application in other areas.

A well-defined heterogeneous palladium catalyst, supported on biomacromolecule, natural wool fibre, was found to be an effective catalyst for the C–C/C–N coupling of pyrimidin-2-yl sulfonates with arylboronic acids, terminal alkynes or anilines, giving the desired coupling products in good to high yields. The catalyst was characterized by XPS, IR, SEM and ICP. More importantly, the easy experimental handling catalyst is stable, shows negligible metal leaching, and can be reused for at least 10 successive runs. Undoubtedly, a wide scope of reactant, insensitive to the electron effects and the excellent coupling yields make these catalyst systems potentially useful in organic synthesis.

Objectives To evaluate the expression of TAZ and its role in tumor invasion and metastasis in human glioma. Methods The expression of TAZ protein was measured in 48 samples of surgically resected human glioma and 13 samples of normal brain tissues using immunohistochemistry. TAZ was knocked down by a retrovirus-mediated TAZ shRNA in a glioma cell line, SNB19. Transwell cell migration and invasion assays were used to determine migration and invasion of SNB19 cells. Results The positive expression rate of TAZ protein in glioma tissues was significantly higher than that in normal brain tissues (79.2% vs. 15.4%, P 0.001). Furthermore, clinical analysis suggested that the positive expression rate of TAZ protein in poorly differentiated tumor tissues was significantly higher as compared with that in well differentiated tissues (96.0% vs. 60.9%, P 0.01). TAZ was significantly knocked down by TAZ shRNA ( P 0.001), and TAZ knockdown significantly reduced cell migration and invasion ( P 0.01, respectively) in SNB19 cells. Conclusions TAZ protein overexpression is observed in human glioma and its elevated expression is significantly correlated with poor differentiation. TAZ knockdown prominently reduces cell migration and invasion in SNB19 cells, suggesting that TAZ may play a key role in the initiation and progression of human glioma.

Ordered Ni/Fe shell/core structured nanocable arrays were successfully fabricated by a two-step electrodeposition process. Firstly, nickel (Ni) nanotubes were prepared by electrodeposition in nanoporous of anodic aluminum oxide (AAO) template. Then the AAO/Ni nanotube composite membrane was used as a secondary template to deposit Ferrum (Fe) nanowires into Ni nanotubes. The morphology and microstructure of the nanocables was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The chemical composition of the nanocables was confirmed by X-ray diffraction (XRD). Magnetization measurements revealed that Ni/Fe nanocable arrays have a lower remanence ratio than Ni nanotube and Fe nanowire arrays respectively.

In this paper, a set of 3D general solutions to static problems of 1D hexagonal piezoelectric quasicrystals is obtained by introducing two displacement functions and utilizing the rigorous operator theory. All the physical quantities are expressed by five quasi-harmonic functions. Based on the general solutions and with the help of the superposition principle, fundamental solutions for infinite/half-infinite spaces are presented by trial-and-error technique. The general solutions can be conveniently used to solve the boundary value problems regarding dislocations, cracks and inhomogeneities. The fundamental solutions are of primary significance to development of numerical codes such as boundary element method.

This paper presents a set of axisymmetric analytical solutions of the thermo-elasticity field induced by the external thermal load, in a heterogeneous circular plate. The plate can be either simply supported or clamped, and the properties of the transversely isotropic material are assumed to be functions of the thickness coordinate. Three typical types of thermal boundary conditions are considered and the corresponding temperature fields are determined. A direct displacement method is used to solve the governing equations for the elastic field in plate. The displacement functions pertinent to the current problem are solved by a step-by-step procedure of integration. The corresponding integral constants are determined by using the cylindrical boundary conditions in the Saint-Venant’s sense. In the present solutions, all of the material coefficients can vary independently and continuously along the thickness direction. Numerical calculations are performed to validate the present solutions and to show their applications to a heterogeneous model. The influence of the material heterogeneity is finally addressed. Since no ad hoc hypotheses on the elastic deformations of the plate are introduced, the present solution can be a nature benchmark to various plate theories and numerical codes.

This Letter is concerned with thermo-elastic fundamental solutions of an infinite space, which is composed of two half-infinite bodies of different one-dimensional hexagonal quasi-crystals. A point thermal source is embedded in a half-space. The interface can be either perfectly bonded or smoothly contacted. On the basis of the newly developed general solution, the temperature-induced elastic field in full space is explicitly presented in terms of elementary functions. The interactions among the temperature, phonon and phason fields are revealed. The present work can play an important role in constructing farther analytical solutions for crack, inclusion and dislocation problems.

Due to the stiffness and damping controllability of magnetorheological elastomer under external magnetic field, it has attracted great attention in the field of vibration control. In order to realize the vibration control system, accurate modeling of magnetorheological elastomer isolator is necessary. However, for the highly nonlinearity and inherently hysteresis of isolator, the existing parametric modeling methods are required to identify too many parameters and the corresponding inverse model cannot be derived from it. Therefore, this paper proposes a nonparametric neural network to approximate the dynamic behaviors of the magnetorheological elastomer isolator. Firstly, the dynamic characteristics of the isolator with shear-compression mixed mode are experimentally tested under different loading conditions. Next, based on these experimental data, the forward model of the isolator is established by using recurrent neural network. Finally, the effectiveness of the network model is validated by comparing the experimental and predicted responses of the isolator, and the results show that the performance of recurrent neural network outperforms that of BP network.

This Letter presents three-dimensional general solutions for static problems in thermo-elasticity of one-dimensional hexagonal quasi-crystals. Two displacement potentials are introduced to simplify the equilibrium equations in terms of displacement and temperature. Rigorous operator theory and generalized Almansiʼs theorem are applied to derive the general solutions in terms of five quasi-harmonic functions. To show the significance of the general solutions, a semi-infinite space and an infinite space, both of which are subjected to a heat source, are considered. In these two cases, closed form fundamental phonon–phason-elastic fields are expressed by elementary functions, which play an important role in numerical simulations.

In this work, large area polymer nanostructure arrays with different patterns were successfully obtained by photolithographic approach and wetting anodic aluminum oxide (AAO) templates. First of all, the AAO templates with patterns were produced by photolithographic approach. Then the AAO/pattern membrane was used as a secondary template to fabricate polymer nanostructure arrays by solution-wetting and melt-wetting methods. The morphology of the polymer nanostructures has been characterized using scanning electron microscopy and transmission electron microscopy. The different factors have been discussed in the process of experiments.

Highly ordered circular patterns of copper nanowire arrays were successfully deposited into designed anodic aluminum oxide templates. High-resolution transmission electron microscopy was used to study the microstructure of these Cu nanostructures. The results showed that the growth orientation of the copper nanowires was along [220] direction, and the broken orientation were along [202] and [022] directions, respectively. Regular cones were formed at the broken end of nanowires. Bent nanowires were also observed, this means that the copper nanowires have good mechanical properties when applied external force. Chemical analysis has been performed on Cu nanowires using electron energy-loss spectroscopy.

Patterned polystyrene (PS) nanotube arrays were successfully fabricated using photolithography via the polymer solution-wetting method. The microstructure of these nanotubes was investigated using conventional and high-resolution transmission electron microscopy (HRTEM). Two major types of morphology were observed for these PS nanotubes, one being bamboo-like and the other being barrel-shaped. The multiwetting mechanism was proposed to explain the different morphologies. X-ray diffraction (XRD) showed that the PS nanotubes have a higher degree of crystallinity than bulk PS. In addition, crystalline lattice fringes were observed in some regions of the PS nanotubes using HRTEM. Patterned polymer nanotube arrays could be used for nanocable coating to protect from oxidation and corrosion in nanodevices.

A well-defined heterogeneous palladium catalyst, supported on biomacromolecule, natural wool fibre, was found to be an effective catalyst for the C–C/C–N coupling of pyrimidin-2-yl sulfonates with arylboronic acids, terminal alkynes or anilines, giving the desired coupling products in good to high yields. The catalyst was characterized by XPS, IR, SEM and ICP. More importantly, the easy experimental handling catalyst is stable, shows negligible metal leaching, and can be reused for at least 10 successive runs. Undoubtedly, a wide scope of reactant, insensitive to the electron effects and the excellent coupling yields make these catalyst systems potentially useful in organic synthesis.

Glioma is the most common and aggressive type of primary brain tumor. MicroRNA (miR)-130b functions as a tumor-associated miR. The dysregulation of miR-130b is involved in numerous biological characteristics and properties of certain types of cancer. The present study revealed the function and possible molecular mechanism of miR-130b in glioma cells, reporting that the level of miR-130b was markedly higher, increasing progressively as the histologic grade of the glioma increased, compared with the level in normal tissues. Additionally, the present study demonstrated that patients with high miR-130b expression exhibited a poor 3-year survival rate and miR-130b was an independent factor for predicting the prognosis of patients with glioma. The downregulation of miR-130b reduced invasion and migration in U373 and U87 cells. Furthermore, the downregulation of miR-130b increased peroxisome proliferator-activated receptor-γ (PPARγ) expression and inhibited epithelial-mesenchymal transition (EMT) in glioma cells. The present study identified PPARγ as a direct target of miR-130b in glioma in vitro. Furthermore, PPARγ knockdown was revealed to reduce the effect on EMT caused by the downregulation of miR-130b in U87 cells. The present study demonstrated that miR-130b promotes glioma proliferation, migration and invasion by suppressing PPARγ and subsequently inducing EMT.

There is growing interest in energy scavenging from natural vibration sources to power autonomous wireless telemetry devices. Vibration energy is typically converted into electrical energy using piezoelectric, electromagnetic, or electrostatic transduction mechanisms [1]. Despite the transduction mechanisms and novel structures, there is still an obstacle facing realistic implementation in most of the vibration-based energy harvester, because they are deigned to harvest energy in a single direction of the ambient vibrations. But a vibration source in real environment may exhibit several motion directions over time. Hence, they may not generate power effectively in the case of a motion with multiple or time-variant motion directions. To address this issue, Moss et al. proposed a bi-axial oscillator to extract vibration energy with arbitrary motion directions in a plane [2]. However, the AISI 52100 ball oscillating on the surface of the Terfenol-D will damage the transducer inevitably, and the bandwidth of the harvester was narrow (about 1 Hz).

Magnetoelectric (ME) laminate composites have emerged as promising candidates for the development of highly sensitive magnetic field sensors at resonance frequency in recent years. Unfortunately, ME coefficient decreases dramatically and the noise level increases at low frequencies far from resonance, which leads to a significant reduction in sensitivity. For the purpose of removing these drawbacks, ME laminate composites have also been employed as weak magnetic field and current sensors at low frequencies, via a sine wave modulation technique [1]-[3]. The new technique offers the possibility to achieve resonance enhanced sensitivities at low frequencies. However, the magnetic field sensitivities of these proposed ME sensors by using sine wave modulation technique are still weak at power-line frequency of 50 Hz.

This paper studies vibration control of flexible beam using a piezoelectric stack actuator (PSA). The working frequency bandwidth of the PSA is experimentally measured. The modal frequency and modal shape of the flexible beam mounted with PSA are obtained by ANSYS modal analysis, and is also verified by experimental test. In order to attenuate the vibration of the flexible beam, a fuzzy controller (FC) is designed and experimentally realized. Acceleration responses of the structural system are evaluated experimentally under resonant and non-resonant excitation conditions. Compared to the peak value of the acceleration without control, the valve with fuzzy control is attenuated by 57.02%.

Over the last decade, multiferroic laminate heterostructures, consisting of the piezoelectric layer (such as PZT) and the magnetostrictive layer (such as Terfenol-D), have attracted considerable attention due to their high Curie or Neel temperature and large magnetoelectric (ME) effect at room temperature. The ME laminate materials have demonstrated potential in many applications such as transducers, actuators, magnetic field sensors, energy harvesters, and other devices [1]. ME effect in the multiferroic laminated heterostructures is essentially attributed to the elastic coupling between the piezoelectric and magnetostrictive layers [2]. The effective piezomagnetic coefficient and effective mechanical quality factor play a key role in the performance of the ME materials. However, owing to the small values of the mechanical quality factor and relative permeability, the ME voltage coefficient of the traditional Terfenol-D/PZT (MP) composites is difficult to increase [3, 4]. The nanocrystalline FeCuNbSiB soft magnetic alloy would be a good solution, according to the large interface stress-strain coupling effects. In this paper, a series of FeCuNbSiB/Terfenol-D/PZT (F/M/P) multi-phase laminate heterostructures are presented (Fig. 1), whose ME coupling characteristics have been investigated. Compared to traditional MPM, the ME coupling characteristics of the proposed FMPMF heterostructures were significantly improved. The resonant and low-frequency ME voltage coefficient of the proposed F/M/P heterostructures could be tuned by controlling the layer numbers N. When N is 7 (FMPMPMF), the maximum value of resonant ME voltage coefficient achieves 8.69 V/Oe, which is about 3.65 times higher than that for FMP, 1.81 times higher than that for FMPMF (Fig. 2(a)). Meanwhile, the maximum value of low-frequency ME voltage coefficient for FMPMPMF heterostructures achieves 69.6 mV/Oe at H b =378 Oe (Fig. 2(b)). Remarkably, it indicates that the F/M/P heterostructures have great potential as far as its application in highly sensitive dc magnetic field sensing and vibration energy harvesting.

This article shows how two colleagues, one Chinese, one British, are learning to work together in a Teachers’ College in northwest China as we help to facilitate change in our organization. The change constitutes the setting up of action research enquiries as a way of enhancing learning and professional development together with changes in The New Curriculum for the teaching of English. Tentative conclusions are drawn about our educational influence on each other, colleagues in our department and beyond, as well as its effects on curriculum development. By working through our assumptions we show some of the benefits of our collaboration and how we have overcome some fundamentally different precepts about education. The most profound of these are concerned with the differing epistemological norms and attitudes to collectivism and individualism. We discover the significance of keeping open minds in enhancing our insights and actions and in our conclusion look to the possible characteristics of our collaboration in the future.

This paper is devoted to investigating the thermal-induced electric and magnetic polarization saturations (PS) at the tip of a penny-shaped crack embedded in an infinite space of magneto-electro-thermo-elastic medium. In view of the symmetry with respect to the cracked plane, this crack problem is formulated by a mixed boundary value problem. By virtue of the solution to the Abel type integral equation, the governing equations corresponding to the present problem are analytically solved and the generalized crack surface displacement and field intensity factors are obtained in closed-forms. Applying the hypothesis of the electric and magnetic PS model to the analytical results, the sizes of the electric and magnetic yielding zones are determined. Numerical calculations are carried out to reveal the influences of the thermal load and the electric and magnetic yielding strengths on the results, and to show the distributions of the electric and magnetic potentials on the crack surfaces. It is found that the sizes of electric and magnetic yielding zones are mainly dependent on the electric and magnetic yielding strengths, respectively. Since the multi-ferroic media are widely used in various complex thermal environments, the present work could serve as a reference for the designs of various magneto-electric composite structures.