International Journal of Modern Physics B

Soft composites with improved and tunable thermal conductivity, stretchability and load-bearing capacity may find fascinating applications in soft robotics and wearable devices. Unfortunately, thermally conductive soft composites with solid fillers usually show serious degradation in stretchability, while those with liquid fillers usually possess a weak load-bearing capacity. To overcome these limitations, an elastomeric composite with solid–liquid multiphase fillers, named as pre-mixed LM&FG/SR composite, is proposed here by incorporating flake graphite (FG) with high thermal conductivity into liquid metal (LM) and then dispersing the mixture in a soft silicone elastomer (SR). In comparison with the LM/SR composite and the FG/SR composite, the pre-mixed LM&FG/SR composite gains the highest thermal conductivity under the strain-free state as it possesses both the excellent thermal conductivity of the FG filler and the high-volume fraction of the LM filler. In addition, by controlling the volume fraction of the multiphase fillers and the volume ratio of LM to FG, the pre-mixed LM&FG/SR composite can gain tunable thermal and mechanical properties under the strained state and thus be applicable to complex situations in which both excellent heat-conducting capability and certain load-bearing capacity are required.

In the recent years, nanotechnologies have been widely used in several fields regarding their rapid developments which creates a lot of prospects for researchers and engineers. More specifically, replacement of conventional liquids with nanoliquids is considered as an innovative solution to heat transfer problems. Keeping the aforesaid pragmatism of nanofluid in view, we have considered a time-dependent mathematical model to formulate the heat sink–source-based Sutterby liquid under thermophoretic and Brownian movements with wedge geometry. Additionally, convective condition, heat sink/source and chemical reaction properties are considered. Appropriate similarity transformations are used to obtain ordinary differential equations (ODEs) from the corresponding PDEs. Furthermore, coupled ODEs are tackled numerically by technique bvp4c in MATLAB. Discussion for thermal and concentration distribution is also presented graphically. Moreover, the temperature field enhance for Brownian parameter and decays for concentration field in this study. A similar impact has been examined for unsteadiness and chemical reaction parameters on concentration plot. Thermal distribution declines for boosted Prandtl number.

The diffusion of salty ions has a great impact on the motor ability of muscle, and revealing the diffusion properties of ions with different concentrations in phospholipid bilayer under electric field is of great significance to the study of ion loss on the skin. In this paper, the diffusion properties of charged ions under electric field are studied by molecular dynamics (MD) simulations. Mean square displacement (MSD) was studied to reveal the displacement of ions in phospholipid bilayer. In addition, the relative concentration is also utilized to reveal the local concentration of ions in the direction of the electric field. The data shows that the negatively charged ions (Cl${}^{-}$, HCO₃ HCO${}_3^{-}$, SO${}_4^{2-})$ have much stronger diffusion capacity, compared to the positive charged ions (Na${}^{+}$, K${}^{+}$, Mg${}^{2+})$ in the simulation systems. Furthermore, the diffusion property of ions becomes stronger with the increase of ion concentration.

We relate the phase separation observed in many crystals with pronounced electron correlations to the regions of negative electron compressibility (NEC). They were found in several models describing strong electron correlations. At low temperatures, these regions arise near chemical potentials corresponding to the change of the ground state in the site Hamiltonian. The NEC leads to the separation of the system into electron-rich and electron-poor domains. The energy released in the course of this separation is absorbed by phonons. Another role of phonons is to give a definite form — stripes or checkerboards — to lattice distortions and domains of different electron concentrations. The shape, direction and periodicity of such textures are determined by wavevectors of lattice distortions, which most strongly scatter electrons.

In this paper, a (3+1)-dimensional generalized Konopelchenko–Dubrovsky–Kaup–Kupershmidt equation (gKDKK) is investigated. Based on Bell polynomial theory, the bilinear form, Bilinear Bäcklund transformation, Lax pair and infinite conservation laws of the equation are obtained. Lump solution and half periodic kink solution are obtained by combining the test function with bilinear form. Furthermore, with the help of the variable separation method, we obtain some new compound solutions composed of exponential function, trigonometric function, hyperbolic function, rational function and Jacobi elliptic function in various forms. Using computer software to draw the three-dimensional diagram and profile of the solutions, the dynamic properties of the solutions are analyzed.

This work presents the results of a study of the photoelectric properties of single crystals of the TlGa${}_x$In${}_{1-x}$Se₂ system of solid solutions based on TlInSe₂ with high photo and tensile sensitivity and switching properties with memory and TlGaSe₂ with high photosensitivity in the visible and infrared regions of the spectrum. Single crystals of the above alloys were grown by the Bridgman–Stockbarger methods. Investigated alloys correspond in $x=0$, 0.1, 0.2, 0.3, 0.4, 0.7, 0.8, 0.9, 1 compounds. It was revealed that these alloys are photosensitive materials, and with a decrease in $x$ from 1 to 0, a shift of the spectral characteristic maxima from 0.57$\mu$m to 1.35$\mu$m is observed. The specific resistance at 77–300 K and the bandgap of the investigated phases have been determined. It was found that with an increase in the content of Ga in the composition of solid solutions, the bandgap increases from 1.23 eV to 2.15 eV.

Dragonflies fly in flapping wing flight, bearing a variety of variable forces during flight. To comprehend and study from the biological system and then carry out technological innovation, the characteristic point cloud data of dragonfly wings were obtained and the 3D geometric models were reconstructed. The biomechanical characteristics of Costa, Radius and Postal veins of the wings were examined by a nanoindenter. It was shown that the reduced modulus and nanohardness of Radius of dragonfly forewings and hindwings are large. The maximum reduced modulus and nanohardness of Costa, Radius and Postal veins of hindwings appear at the place 0.7L of dragonfly wings. The biomechanical characteristics of dragonfly wings were researched and then the deformations and stresses of the bionic models under the uniform load were investigated. It was shown that the dragonfly wings are less deformed under the uniform load and the chief veins have stronger stability and bearing capacity. The combinations of the main veins and branch veins can improve the overall strength and load-bearing capacity of dragonfly wings. It tries to explore the structural models of imitating dragonfly wings with good load-bearing capacity and, then, were used to guide the plan and manufacturing of thin film and offer novel ideas and methods for the study of thin film.

The simplified form of the Hirota bilinear method is used to investigate a $(3+1)$-dimensional generalized B-type Kadomtsev–Petviashvili (gBKP) equation, and the five-soliton is formally derived. Applying the long-wave limit to the five-soliton and establishing the complex conjugate relations in the parameters of the five-soliton, five types of hybrid solutions of the $(3+1)$-dimensional gBKP equation are obtained. Furthermore, the dynamical behaviors of the hybrid solutions are systematically analyzed via numerical simulations.

The crystallization and sintering process of RuO${}_2\cdot$xH₂O nanoparticles have been investigated in this paper. The effect of RuO₂ crystallinity and particle size on the sheet resistance of RuO₂-based resistor paste after being co-fired with CaO–B₂O₃–SiO₂ green tapes has been reported. The results show that the nanoparticles are not fully crystallized below 600${}^{\circ }$C, and the effect of high-density defects, such as grain boundaries and dislocations on the residual resistance ($R_r)$ of RuO₂ particles, is significant. So, the sheet resistance decreases with the increase of crystallinity and the weakening of electron wave scattering. Above 600${}^{\circ }$C, the effect of crystal imperfections on $R_r$ is greatly weakened. However, the number of conductive chains formed in co-fired resistor decreases with the increase of particle size, thus the sheet resistance gradually raises. When the dwelling time is increased to 3 h, the RuO₂ is mostly crystallized and the effect of crystal imperfections on $R_r$ is negligible, and the sheet resistance mainly depends on particle size of RuO₂. Using RuO₂ particles with low crystallinity, small size and narrow particle-size distribution as conductive phase is expected to solve the problem of poor sheet resistance uniformity in high resistance paste for LTCC application.

In this paper, we developed a shunt-current intensity self-adjustable closed-loop control circuit system for current conduction treatment in temporal lobe epilepsy. To examine the dose-response relationship between conductive intensity and therapeutic outcomes of current conduction treatment, the control system consists of neural signal recording module for high-speed data rate acquisition, signal amplification and pre-processing, current shunt module for current conduction, data transmission and control module for real-time data communication with the personal computer and on-off of current conduction. Multithread and queue software architecture was implemented to ensure real-time data transmission, display and analysis by LabVIEW software. Results indicate that the input noise of the system is less than 2 $\mu$Vrms, signal frequency bandwidth range is 1 Hz$\sim$10 kHz, and the shunt-current detection range is 0.1–3000 $\mu$A with the accuracy of above 99.985%, meeting the requirements for the detection of neural electrophysiological signal and the research on the dose-response relationship between conductive intensity and therapeutic outcomes of electronic conduction treatment.