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<jats:p>In order to explore the stability of a liquid crystal (LC) system doped with <jats:italic>γ</jats:italic>-Fe<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanoparticles, the physical properties (clearing point, dielectric properties), electro-optical properties and residual direct-current voltage (RDCV) of the doped LC system were measured and evaluated at different times. First, the temperature was controlled by precision hot stage, and the clearing point temperature of doped LC was observed and measured by a polarized optical microscope. Using a precision LCR meter, we measured the capacitance-voltage curves of the doped LC system at the temperature of 27 °C. The dielectric constant of doped LC was calculated by the dualcell capacitance method. Then, the electro-optical properties of the doped LC system were measured. Finally, the RDCV of the doped LC system was measured and calculated. After five months, the parameters of the doped LC system were re-measured and analyzed under the same conditions to evaluate its stability. The experimental results show that, within five months, the clearing point change rate of doped LC is in the range of 0.24%–1.37%, the change of dielectric anisotropy is in the range of 0.035–0.2, the curves of electro-optical properties are basically fitted, and the change rate of saturated RDCV is about 11.2%, which basically indicate that the LC system doped with <jats:italic>γ</jats:italic>-Fe<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanoparticles has good stability.</jats:p>

<jats:p>Ni–Zn ferrite and Bi<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> composites were developed by the sol-gel method. The structural, magnetic, and dielectric properties were studied for all the prepared samples. X-ray diffraction (XRD) was performed to study the crystal structure. The results of field emission scanning electron microscopy (FE-SEM) showed that the addition of Bi<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> can increase the grain size of the Ni–Zn ferrite. Magnetic properties were analyzed by a hysteresis loop test and it was found that the saturation magnetization and coercivity decreased with the increase of Bi<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> ratio. In addition, the dielectric properties of the Ni–Zn ferrite were also improved with the addition of Bi<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>.</jats:p>

<jats:p>Based on Dirac semimetal metamaterials, the tunable plasmon induced transparency (PIT) is investigated elaborately in this work. The designed unit cell consists of a strip and a square bracket, which is periodically aligned on the dielectric substrate. Our numerical results illustrate that a pronounced transparency window exists due to near field coupling between two bright modes, which can be dynamically tuned with Fermi energy. Namely, the transparency window demonstrates a distinct blue shift with a larger Fermi energy. Moreover, an on-to-off switch of the PIT transparency window is realized with different polarization angles. In addition, the accompanied slow light property is examined with the calculation of phase and group delay. Finally, a small variation of the refractive index of the substrate can induce a clear movement of the PIT transparency window which delivers a guidance in the application of optical sensing. Thus, this work provides us a new strategy to design compact and adjustable PIT devices and has potential applications in highly tunable optical switchers, sensors, and slow light devices.</jats:p>

<jats:p>SiGe spheres with different diameters are successfully fabricated on a virtual SiGe template using a laser irradiation method. The results from scanning electron microscopy and micro-Raman spectroscopy reveal that the diameter and Ge composition of the SiGe spheres can be well controlled by adjusting the laser energy density. In addition, the transmission electron microscopy results show that Ge composition inside the SiGe spheres is almost uniform in a well-defined, nearly spherical outline. As a convenient method to prepare sphere-shaped SiGe micro/nanostructures with tunable Ge composition and size, this technique is expected to be useful for SiGe-based material growth and micro/optoelectronic device fabrication.</jats:p>

<jats:p>In view of the importance of enhancing ferromagnetic (FM) coupling in dilute magnetic semiconductors (DMSs), the effects of strain on the electronic structures and magnetic properties of (Ga,Fe)Sb were examined by a first-principles study. The results of the investigation indicate that Fe<jats:sub>Ga</jats:sub> substitution takes place in the low-spin state (LSS) with a total magnetic moment of 1<jats:italic>μ</jats:italic> <jats:sub>B</jats:sub> in the strain range of –3% to 0.5%, which transitions to the high-spin state (HSS) with a total magnetic moment of 5<jats:italic>μ</jats:italic> <jats:sub>B</jats:sub> as the strain changes from 0.6% to 3%. We attribute the changes in the amount and distribution of the total moment to the influence of the crystal field under different strains. The FM coupling is strongest under a strain of about 0.5%, but gradually becomes weaker with increasing compressive and tensile strains. The magnetic coupling mechanism is discussed in detail. Our results highlight the important contribution of strain to magnetic moment and FM interaction intensity, and present an interesting avenue for the future design of high Curie temperature (<jats:italic>T</jats:italic> <jats:sub>C</jats:sub>) materials in the (Ga,Fe)Sb system.</jats:p>

<jats:p>The neutron Bragg-edge imaging is expected to be a new non-destructive energy-resolved neutron imaging technique for quantitatively two-dimensional or three-dimensional visualizing crystallographic information in a bulk material, which could be benefited from pulsed neutron source. Here we build a Bragg-edge imaging system on the General Purpose Powder Diffractometer at the China Spallation Neutron Source. The residual strain mapping of a bent Q235 ferrite steel sample has been achieved with a spectral resolution of 0.15% by the time-of-flight neutron Bragg-edge imaging on this system. The results show its great potential applications in materials science and engineering.</jats:p>

<jats:p>Zn<jats:sub>1–<jats:italic>x</jats:italic> </jats:sub>Mg<jats:sub> <jats:italic>x</jats:italic> </jats:sub>O alloy films are important deep ultraviolet photoelectric materials. In this work, we used plasma-assisted molecular beam epitaxy to prepare Zn<jats:sub>1–<jats:italic>x</jats:italic> </jats:sub>Mg<jats:sub> <jats:italic>x</jats:italic> </jats:sub>O films with different magnesium contents on polar (0001) and nonpolar (<jats:inline-formula> <jats:tex-math><?CDATA $10\bar{1}0$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>10</mml:mn> <mml:mover accent="true"> <mml:mn>1</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> <mml:mn>0</mml:mn> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_9_096107_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>) ZnO substrates. The nanoscale structural features of the grown alloy films as well as the interfaces were investigated. It was observed that the cubic phases of the alloy films emerged when the Mg content reached 20% and 37% for the alloy films grown on the (0001) and (<jats:inline-formula> <jats:tex-math><?CDATA $10\bar{1}0$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>10</mml:mn> <mml:mover accent="true"> <mml:mn>1</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> <mml:mn>0</mml:mn> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_9_096107_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>) ZnO substrates, respectively. High-resolution transmission electron microscopy images revealed cubic phases without visible hexagonal phases for the alloy films with more than 70% magnesium, and the cubic phases exhibited three-fold and two-fold rotations for the alloy films on the polar (0001) and nonpolar (<jats:inline-formula> <jats:tex-math><?CDATA $10\bar{1}0$?></jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>10</mml:mn> <mml:mover accent="true"> <mml:mn>1</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> <mml:mn>0</mml:mn> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_9_096107_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula>) ZnO substrates, respectively. This work aims to provide references for monitoring the Zn<jats:sub>1–<jats:italic>x</jats:italic> </jats:sub>Mg<jats:sub> <jats:italic>x</jats:italic> </jats:sub>O film structure with respect to different substrate orientations.</jats:p>

<jats:p>Novel properties and applications of multilayered nanowires (MNWs) urge researchers to understand their mechanical behaviors comprehensively. Using the molecular dynamic simulation, tensile behaviors of Ti/Ni MNWs are investigated under a series of layer thickness values (1.31, 2.34, and 7.17 nm) and strain rates (<jats:inline-formula> <jats:tex-math> <?CDATA $1.0\times {10}^{8}\,{{\rm{s}}}^{-1}\le \mathop{\varepsilon }\limits^{.}\le 5.0\times {10}^{10}\,{{\rm{s}}}^{-1}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mn>1.0</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>8</mml:mn> </mml:msup> <mml:mspace width="0.25em" /> <mml:msup> <mml:mi mathvariant="normal">s</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mo>≤</mml:mo> <mml:mover> <mml:mi>ε</mml:mi> <mml:mo>.</mml:mo> </mml:mover> <mml:mo>≤</mml:mo> <mml:mn>5.0</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em" /> <mml:msup> <mml:mi mathvariant="normal">s</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_9_096201_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>). The results demonstrate that deformation mechanisms of isopachous Ti/Ni MNWs are determined by the layer thickness and strain rate. Four distinct strain rate regions in the tensile process can be discovered, which are small, intermediate, critical, and large strain rate regions. As the strain rate increases, the initial plastic behaviors transform from interface shear (the shortest sample) and grain reorientation (the longest sample) in small strain rate region to amorphization of crystalline structures (all samples) in large strain rate region. Microstructure evolutions reveal that the disparate tensile behaviors are ascribed to the atomic fractions of different structures in small strain rate region, and only related to collapse of crystalline atoms in high strain rate region. A layer thickness-strain rate-dependent mechanism diagram is given to illustrate the couple effect on the plastic deformation mechanisms of the isopachous nanowires. The results also indicate that the modulation ratio significantly affects the tensile properties of unequal Ti/Ni MNWs, but barely affect the plastic deformation mechanisms of the materials. The observations from this work will promote theoretical researches and practical applications of Ti/Ni MNWs.</jats:p>

<jats:p>Damage depth is an important dynamic parameter for describing the degree of material damage and is also a key fundamental issue in the field of impact compression technology. The present work is dedicated to the damage depth of shock-melted metal in microspall under triangular wave loading, and an improved model of damage depth considering the material’s compressibility and relative movement is proposed. The damage depth obtained from the proposed model is in good agreement with the laser-driven shock loading experiment. Compared with the previous model, the proposed model can predict the damage depth of shock-melted metal in microspall more accurately. Furthermore, two-groups of the smoothed particle hydrodynamics (SPH) simulations are carried out to investigate the effects of peak stress and decay length of the incident triangular wave on the damage depth, respectively. As the decay length increases, the damage depth increases linearly. As the peak stress increases, the damage depth increases nonlinearly, and the increase in damage depth gradually slows down. The results of the SPH simulations adequately reproduce the results of the proposed model in terms of the damage depth. Finally, it is found that the threshold stress criterion can reflect the macroscopic characteristics of microspall of melted metal.</jats:p>

<jats:p>Vanadium dioxide (VO<jats:sub>2</jats:sub>) is a strongly correlated material, and it has become known due to its sharp metal-insulator transition (MIT) near room temperature. Understanding the thermal properties and their change across MIT of VO<jats:sub>2</jats:sub> thin film is important for the applications of this material in various devices. Here, the changes in thermal conductivity of epitaxial and polycrystalline VO<jats:sub>2</jats:sub> thin film across MIT are probed by the time-domain thermoreflectance (TDTR) method. The measurements are performed in a direct way devoid of deposition of any metal thermoreflectance layer on the VO<jats:sub>2</jats:sub> film to attenuate the impact from extra thermal interfaces. It is demonstrated that the method is feasible for the VO<jats:sub>2</jats:sub> films with thickness values larger than 100 nm and beyond the phase transition region. The observed reasonable thermal conductivity change rates across MIT of VO<jats:sub>2</jats:sub> thin films with different crystal qualities are found to be correlated with the electrical conductivity change rate, which is different from the reported behavior of single crystal VO<jats:sub>2</jats:sub> nanowires. The recovery of the relationship between thermal conductivity and electrical conductivity in VO<jats:sub>2</jats:sub> film may be attributed to the increasing elastic electron scattering weight, caused by the defects in the film. This work demonstrates the possibility and limitation of investigating the thermal properties of VO<jats:sub>2</jats:sub> thin films by the TDTR method without depositing any metal thermoreflectance layer.</jats:p>