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In order to understand the effects of nitrogen ionization during preparation and oxygen pressure during annealing (OPA) on the morphology, structure, and luminescent properties of Mg-doped ZnO thin films, Zn0.97Mg0.03O films were prepared in both ionized and non-ionized N2 using Pulsed Laser Deposition (PLD), followed by annealing at 600 °C under various oxygen pressures. X-ray Diffraction (XRD) results reveal that all Zn0.97Mg0.03O films exhibit a preferentially oriented hexagonal wurtzite structure along the (002) direction, with the films prepared in ionized nitrogen showing the presence of Zn3N2 phase. Field Emission Scanning Electron Microscopy (FESEM) observations indicate that the films prepared in non-ionized and ionized N2 exhibit near-spherical and conical shaped particles, respectively. Combined XRD and X-ray Photoelectron Spectroscopy (XPS) analyses indicate an increase in Zn interstitial (Zni) content in the films after annealing, with higher content observed at a higher OPA; films annealed under oxygen pressure of 100 Pa exhibit maximum tensile stress and highest N content. Photoluminescence (PL) spectra of both ionized and non-ionized films reveal a strong ultraviolet-violet peak (360–450 nm) and weaker blue-green peak (450–550 nm), with a broad and weak near-infrared (NIR) peak around 825 nm. The NIR peak primarily originates from the recombination of electrons bound to Zni and holes bound to oxygen vacancies (Vo) ; ionization of nitrogen enhances the green emission. [ABSTRACT FROM AUTHOR]

Acoustic metasurface is a membrane-like two-dimensional metamaterial with subwavelength thickness and special acoustic properties. Based on generalized Snell's laws, acoustic metasurface produce a series of unconventional acoustic phenomena including anomalous refraction/reflection. This paper proposes a dual-functional acoustic metasurface composed of asymmetric pentamode units with directional refraction and acoustic isolation. The numerical shows that the acoustic insulation and vibration attenuation can be obtained from 7.0 kHz to 8.4 kHz, while efficient directional transmission can be achieved between 2.0 kHz and 4.0 kHz. This study may provide a pathway for acoustic metasurface to control the acoustic propagation in diodes, insulators and cloaks. [ABSTRACT FROM AUTHOR]

The yarn ball-like NiCo-LDH was electrodeposited on carbon paper (CP) through adjusting and controlling the synthetic parameters such as cobalt ion concentration, synthetic potential and time by potentiostatic deposition, and was constructed an enzyme-free glucose sensor; the electrocatalytic behavior of the as-prepared NiCo-LDH/CP electrode towards the glucose was investigated through cyclic voltammetry (CV) and amperometric current–time response (I-t). The results showed that the sensor constructed on the basis of as-prepared NiCo-LDH/CP had not only a wide range of 0.84–11.04 mM, high sensitivity (5810 μA·mM−1·cm−2) and a low detection limit of 0.0546 μM, but also remarkable selectivity, striking repeatability and stability. Besides, the sensor based on NiCo-LDH/CP electrode had an excellent actual measurement with the recoveries of 98.86–101.05%. [ABSTRACT FROM AUTHOR]

In this work, the 30Bi2O3-38B2O3-3SiO2-5Al2O3-(24-x)MnO-xCuO (x = 6, 10, 14, 18, 22 mol%) lead-free bismuth borate glasses were prepared by the melt-quenching method. The effects of CuO substitution for MnO on the structure and properties of the bismuth borate glass were investigated. As the CuO content increases from 6 to 22 mol%, the density of the glass gradually increases while the molar volume shows an opposite trend. The FTIR spectra show that [BiO3], [BiO6], [BO3], and [BO4] are the main structural units in the bismuth borate glass network. The vibrations of both [BiO3] and [BO4] units are enhanced with the increasing CuO content. With the increase of CuO content, the glass transition temperature (Tg) decreases from 438 to 417 ℃ and the softening temperature (Tf) decreases from 470 to 452 ℃. The thermal expansion coefficient (CTE) decreases from 7.875 to 7.702 × 10–6 /℃ in the temperature range of 30–300 ℃, which is between the thermal expansion coefficients of Ag (19 × 10–6 /℃) and silicon substrates (2.5 × 10–6 /℃). In addition, the HF resistance of the bismuth borate glasses gradually improves as the CuO content increases, with a minimum dissolution rate of 14.27 × 10–3 g cm−2 min−1. The NaOH resistance of the bismuth borate glasses initially decreases and then remains stable, with a maximum dissolution rate of 14.66 × 10–3 g cm−2 min−1. The results revealed that the investigated Bi2O3-B2O3-MnO-CuO glass can be used as a suitable alternative to lead-based glass for conductive silver paste. [ABSTRACT FROM AUTHOR]

Galvanostatic electrochemical co-deposition was used to fabricate nickel-based reduced graphene oxide (Ni–rGO) nanocomposite by varying the current density in the range of 3–6 Adm−2 and at rGO loading of 1 g L−1. The process relies on the reduction of oxygenated functional groups of GO. By excessive incorporation and simultaneous reduction of GO in the structure of Ni–rGO composite coatings, the morphology transforms into structure with rough and three-dimensional (3D) features. The formation of Ni–rGO composite coatings was confirmed by investigating 3D morphology by SEM and XRD studies. Furthermore, comprehensive investigation of the thermal diffusivity, density, specific heat capacity, and thermal conductivity of Ni–rGO composite was conducted. Moreover, the relationship between current density and thermal conductivity was also evaluated. The test results indicate that the prepared Ni–rGO composite exhibits excellent thermal conductivity when the current density is 5 A dm−2. Combined with the outstanding performance of corrosion resistance in the early stages, the as-prepared Ni–rGO composite coatings are highly promising for cooling systems in ship and heat dissipation system in ocean electronic equipment. [ABSTRACT FROM AUTHOR]

The antibacterial ability of medical titanium alloy implant in vivo remains a significant challenge for orthopedic implants despite its excellent mechanical and osteoconductive properties. Here, we explored a simple method to improve the antibacterial ability of Ti6Al4V. The silver physically adheres to the surface of the structure by laser interference direct writing after coating the silver film by ion sputtering from 50 to 500 nm; meanwhile, periodic microstripe structure was formed, showing good antibacterial properties against the Gram-positive bacterial Staphylococcus aureus (S. aureus). Moreover, the antibacterial ability was increased with the increase of silver film thickness. While the silver film thickness was larger than 100 nm, the antibacterial rate exceeded 90%. In addition, the Ag+ releases concentration for Ag100nm, Ag300nm, and Ag500nm were also measured from 24 to 120 h, which showed the linear increment with the thickness of Ag thin film and release time. The surface of the structure showed the good bio-compatibility for the MC3T3-E1 cell; simultaneously, the growth of the cell was obviously adjusted by these microstripes. In summary, the Ti6Al4V with these microstripes after Ag modification combines good antimicrobial properties, bio-compatibility and cell growth regulation performance, which showed the potential application as an orthopedic implant in the future. [ABSTRACT FROM AUTHOR]

For facing the environmental challenge induced by the arbitrary release of biowaste, numerous renewable biowastes have served as raw materials for valuable biomaterials, including biowaste-derived natural dyes (BND) and biowaste-derived carbon materials (BCM). The emergence of dye-sensitized solar cells (DSSCs) has paved the way for the application of the BND and BCM in energy conversion field. We investigated the configuration and photovoltaic performance of a dual-biowaste-based DSSCs using the BND as a natural photosensitizer and the BCM as a natural counter electrode catalyst, with emphasis on understanding the influence of the molecular structure of chlorophyll in the BND and the porous structure of the BCM upon the device performance. The BND and BCM were fabricated employing both fallen leaves as the raw materials through facile technique. The chlorophyll with keto C=O in the mulberry leaf extracted BND displays more integrated porphyrin structure than that without keto C=O in the plantain leaf extracted BND, giving the device higher photocurrent density. In contrast, compared with the mulberry leaf pyrolyzed BCM, the plantain leaf pyrolyzed BCM possesses better electrochemical performances owing to its own larger surface areas, more developed mesopore and ordered tubular macropores, which brings about higher fill factor for the device. Consequently, the conversion efficiency (η) of the dual-biowaste-based DSSCs employing the mulberry leaf-derived BND and plantain leaf-derived BCM is 0.28%. Moreover, the BCM used as the catalyst in a typical N719 sensitized cells has higher η in comparison with the graphite, thanks to its own unique porous structure and dual-doped amorphous carbon skeleton with oxygen-containing groups. The η of 1.28% and 1.51% are, respectively, obtained for the mulberry and plantain leaves-based device, whereas that of 0.77% is achieved for the graphite-based one. These results obviously exhibit a facile biowaste valorization into valuable BND and BCM used in energy conversion field. [ABSTRACT FROM AUTHOR]

For the research of metasurfaces, there have been previous studies on scattering that combine light-filed with microwave, but it can only be modulated by controlling each column of metasurface elements. In this paper, we propose a light-sensing metasurface that realizes the independent regulation of arbitrary elements on the metasurface to obtain distinct electromagnetic (EM) functions. By integrating PIN diodes in the 1-bit coding metasurface for phase-response modulation. Each metamaterial unit is embedded with a photoresistor, which can independently sense optical information and convert optical signals into electrical signals. The micro control module directly reflects the change of electrical signal to the PIN diode on the metasurface, forming a pattern of different phase distribution. To verify this idea, four patterns are designed and introduced in this paper. Through simulation and measurement, the experimental results show good agreement with the simulations, which verifies the feasibility of this scheme. [ABSTRACT FROM AUTHOR]

The plunger is the core component of the sucker rod pump. Its rapid wear and premature failure severely limit the efficiency and productivity of oil and gas production. Diamond-like carbon (DLC) films, due to their high hardness, high wear resistance and low friction coefficient, have great research prospects for the development of long-life and high-reliability sucker-rod pump plungers in oil production environments. Therefore, in this paper, to simulate the friction behaviour and influence mechanism of the DLC film in an oil production environment, three molecular dynamics friction models of Fe–Fe, DLC–Fe and DLD–DLC were established. It is found that with increasing load, the friction coefficients of DLC–Fe and DLD–DLC are smaller than that of Fe–Fe in the light oil reservoir environment. In particular, when the mating pair is DLC–DLC, a superlubricity state of 0.0007 is even achieved. This will greatly increase the service life of the plunger of the sucker rod pump in the oil production environment. Further investigation revealed that the low friction of the DLC film in an oil production environment is mainly due to the weak interaction between light oil molecules and the DLC layer, so that it does not cause adhesive wear with the friction surface while lubricating the surface. [ABSTRACT FROM AUTHOR]

Polymer and paper-based microfluidics have been widely used in biological and medical research. In this study, a new alternative material is proposed for the fabrication of microfluidic devices: biodegradable PLA (poly-lactic acid) nonwoven fabrics. Compared to polymer sheets and films, nonwoven fabric material is even more low-cost, flexible, and easy to process. Compared to paper-based microfluidics, nonwoven fabric material is mechanically more robust and provides a wider choice of chemical/physical properties with a cost in the same range. PLA nonwoven fabric is plant-sourced, which has a much lower carbon footprint in the fabrication of nonwoven fabric material compared to other petrochemical-sourced polymers. Due to the hydrophobic properties of PLA nonwoven fabric material, a layer of PVA (polyvinyl alcohol) was deposited and patterned on the surface of the PLA nonwoven fabric to enable fluid self-driven and fluid path control. For the demonstration of the proposed fabrication technique for PLA nonwoven fabric-based microfluidic devices, a microfluidic device for the testing of polyphenol in tea was also fabricated. The proposed fabrication method for PLA nonwoven fabric-based microfluidic devices could have wide application potential in chemical and point-of-care testing as an alternative to polymer or paper-based microfluidics. [ABSTRACT FROM AUTHOR]

Coreless induction furnace is one of the most widely used equipment in the steelmaking sector, while the lining refractory are the key factors in determining the lifetime of the induction furnace. The multi-physics field dominates the operating conditions of the lining refractory which can be well-studied using numerical simulation techniques. Based on the technique, and adopted frequency domain-transient method, the thermal-electromagnetic flow coupled multi-physical fields is simulated and the effects of multi-physical fields on the furnace lining refractory are analyzed as well, which provides a numerical simulation guiding approach for the design of the lining refractory of induction furnace. The results indicate that the excitation magnetic field distribution dominates the multi-physics field distribution, and shows a concentrated field distribution at the bottom corner and slag line, the inner wall of the furnace lining is influenced by the liquid steel impact, the temperature, velocity and stress at the bottom corner, reach 2046 K, 0.127 m/s and 2.34 × 102 MPa respectively. With regards to the simulation results, the service conditions of these two regions and the furnace waist lining should be focused on when designing refractory for induction furnace lining. [ABSTRACT FROM AUTHOR]

NASICON-type LiTi2(PO4)3 (LTP) are gaining enormous attention for applications in solid-state lithium-ion batteries due to its comparatively high conductivities and three-dimensional open-framework. The selective substitution strategies at cationic sites are regarded as an important approach to enhance the ionic conductivity of LTP electrolytes. Present work reports the influence of Ga3+ ions doping on the crystal structure, density, activation energy, and ionic conductivity of Li1+xGaxTi2–x(PO4)3 (x = 0, x = 0.25, x = 0.5, x = 0.75 and x = 1, labeled as LGTP) electrolytes. Herein, we found that the relative density, activation energy, and conductivity of LGTP electrolytes show a tendency to increase first and then decrease as Ga3+ doping increases. The sample with x = 0.5 exhibits the highest ionic conductivity (4.64 × 10–4 S cm−1), the highest relative density (96.21%), and the lowest activation energy (0.17 eV). The conductivity of Li1.5Ga0.5Ti1.5(PO4)3 (LGTP050) increases by three orders of magnitude when compared to LTP without Ga3+ doping, possibly due to its high relative density, low activation energy, and high lithium-ion concentration. These findings suggest that doping LTP ceramic electrolytes with Ga3+ can significantly improve conductivity. [ABSTRACT FROM AUTHOR]

SnSe with layered structure, as a member of 2D materials and transition metal chalcogenides, is a promising candidate of electrocatalyst for hydrogen evolution. Reduced graphene oxide (RGO) is an excellent substrate of electrocatalyst. In this work, SnSe nanosheets (NSs) had been prepared via liquid exfoliation, and the as-prepared SnSe NSs had been hybridized with RGO by a simple hydrothermal method. The SnSe/RGO hybrid shows superior hydrogen evolution reaction (HER) performance and charge transfer capability than SnSe NSs. In addition, it exhibits a superior HER performance in 1.0 M H2SO4 with overpotential of − 298.79 mV (vs. RHE) at a current density of 10 mA/cm2 and a Tafel slope determined to be only 97.56 mV/dec. Moreover, the SnSe/RGO hybrid as working electrode is provided with excellent durability, which is capable of maintaining working current for 10 h. As demonstrated above, relative high activity and stability and low price make the SnSe/RGO hybrid a promising electrocatalyst. [ABSTRACT FROM AUTHOR]

Nb3(Al1–xZnx) (x = 0–0.05) wires were obtained after single rapid heating, quenching and low temperature transformation (single-RHQT) process. It is found that Zn element can make crystal plane diffraction peaks of Nb3Al phase shift to higher angle, and the interplanar crystal spacing decreases gradually, which indicates that Al atoms in Nb3Al lattice are replaced by Zn atoms with smaller diameters. And the addition of Zn can reduce ΔTc and make the superconducting phases purer, and magnetic performances such as critical temperature (Tc), critical current density (Jc), irreversible field (Birr) are better than that of the pure sample. Nb3(Al0.99Zn0.01) wire shows the highest Jc value of about 5.9 × 104 A/cm2 at 4.2 K and 8 T, and the highest Tc value of 16.8 K was found in Nb3(Al0.98Zn0.02). The influence of multiple rapid heating, quenching and low temperature transformation (multi-RHQT) process on Nb3(Al1–xZnx) wires was mainly explored, and 2 at% and 3 at% Zn samples were selected with relatively high ΔTc values for five times RHQT treatment. It is observed that the multi-RHQT process can further reduce ΔTc, and more homogeneous superconducting phases are discovered compared with that of single-RHQT process. The elements are also evenly distributed in the multi-RHQT-processed Nb3(Al1–xZnx) wires, leading to the improvement of Jc, Birr performances compared to single-RHQT samples. Multi-RHQT-processed Nb3(Al0.98Zn0.02) and Nb3(Al0.97Zn0.03) samples show the Jc values of 1.7 × 105 A/cm2 and 1.2 × 105 A/cm2 (4.2 K, 8 T), which are nearly ten times as many as that of single-RHQT samples, and Nb3(Al0.97Zn0.03) has the highest Birr values of 19.6 T (4.2 K) and 10.7 T (10 K). Flux pinning of the Nb3(Al1–xZnx) (x = 0.01–0.05) wires follows the surface pinning mechanism, where grain boundary and stacking faults are considered as pinning centers. [ABSTRACT FROM AUTHOR]

To study the cutting micromechanics of nickel-based single crystal superalloy containing γ/γ´ two-phase structures and strengthening elements, a molecular dynamics method was used to establish a cutting model for nickel-based single crystal superalloy. The variation of machining force, shear strain, atomic displacement, and surface quality were analyzed in depth, and the effect of strengthening element content in the γ phase on the cutting behavior was investigated by comparing different models. It was found that the dislocation tangle is easily formed in the γ phase of nickel-based single crystal superalloy leading to increased machining forces, in addition, the coherent interface is stronger and can block the development of shear strain zones and the displacement of atoms. It is also found that the elastic recovery of γ phase is lower than that of γ´ phase, resulting in the deepest part of the machined surface always appearing in γ phase. Finally, by studying the influence of the content of strengthening elements on the material, it is found that the strengthening elements Cr and Co in γ phase can promote the generation of dislocation tangle, and also enhance the strength of γ phase and coherent interface and improve the deformation resistance of the workpiece. [ABSTRACT FROM AUTHOR]

Nb3(Al1–xZnx) (x = 0–0.05) wires were obtained after single rapid heating, quenching and low temperature transformation (single-RHQT) process. It is found that Zn element can make crystal plane diffraction peaks of Nb3Al phase shift to higher angle, and the interplanar crystal spacing decreases gradually, which indicates that Al atoms in Nb3Al lattice are replaced by Zn atoms with smaller diameters. And the addition of Zn can reduce ΔTc and make the superconducting phases purer, and magnetic performances such as critical temperature (Tc), critical current density (Jc), irreversible field (Birr) are better than that of the pure sample. Nb3(Al0.99Zn0.01) wire shows the highest Jc value of about 5.9 × 104 A/cm2 at 4.2 K and 8 T, and the highest Tc value of 16.8 K was found in Nb3(Al0.98Zn0.02). The influence of multiple rapid heating, quenching and low temperature transformation (multi-RHQT) process on Nb3(Al1–xZnx) wires was mainly explored, and 2 at% and 3 at% Zn samples were selected with relatively high ΔTc values for five times RHQT treatment. It is observed that the multi-RHQT process can further reduce ΔTc, and more homogeneous superconducting phases are discovered compared with that of single-RHQT process. The elements are also evenly distributed in the multi-RHQT-processed Nb3(Al1–xZnx) wires, leading to the improvement of Jc, Birr performances compared to single-RHQT samples. Multi-RHQT-processed Nb3(Al0.98Zn0.02) and Nb3(Al0.97Zn0.03) samples show the Jc values of 1.7 × 105 A/cm2 and 1.2 × 105 A/cm2 (4.2 K, 8 T), which are nearly ten times as many as that of single-RHQT samples, and Nb3(Al0.97Zn0.03) has the highest Birr values of 19.6 T (4.2 K) and 10.7 T (10 K). Flux pinning of the Nb3(Al1–xZnx) (x = 0.01–0.05) wires follows the surface pinning mechanism, where grain boundary and stacking faults are considered as pinning centers. [ABSTRACT FROM AUTHOR]

In this paper, shaped fibers which are especially useful for radiative cooling have been firstly deposited by Electrohydrodynamic direct-writing based on Micro-Weissenberg effect (MWE). At first, The process of pumping viscoelastic fluids (polyethylene oxide) in micro-tube (non-circle nozzle) based on Micro-Weissenberg effect has been studied to reveal the mechanism of Micro-Weissenberg effect. We have found that the pumping based on MWE have obvious periodic fluctuation when the flow rate is small. Then the process of steel pins without small diameter pipes pumping viscoelastic fluid which is a continuous, less wall and controllable pumping manner have been studied in detail. It is found that the pumping based on MWE mainly stem from an interesting capillarity between two pins and the viscoelasticity of fluid. So compare with the traditional Electrohydrodynamic direct-writing, the shaped fibers have been more easily deposited by Electrohydrodynamic direct-writing based on MWE due to the capillarity and the shear thinning in Micro-Weissenberg effect. [ABSTRACT FROM AUTHOR]

Effective modulation of electronic and optical properties for van der Waals heterostructures is beneficial to spintronics and optoelectronic devices. We use first-principle calculations to investigate the effects of intralaminar biaxial strain on the Rashba spin splitting and optical absorption of MoSSe/WSe 2 heterostructures. First, considering the different stacking manners, the most stable configuration is confirmed from six heterostructures. The results show that this is in type II energy band alignment, which effectively reduces the carrier recombination rate. Second, Rashba splitting strength can be effectively modulated by biaxial strain, and splitting occurs at the Γ point, in which the tensile and compressive strains can suppress and promote the strength, respectively. Third, we calculate the dielectric constant and optical absorption of the MoSSe/WSe 2 heterostructure and find a higher optical absorption coefficient in visible light scope than two monolayers, and the maximum value can reach 6.11 × 10 5 cm - 1 . The first absorption peak of the heterostructure increases with increasing tensile strain and the absorption edge is red shifted. On the contrary, there is an opposite effect under compressive strain. These results suggest that MoSSe/WSe 2 heterostructures have potential applications in strain-tunable spintronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this work, a CuxS/GO composite hole transport layer is prepared on the surface of TiO2/CuInS2 photo-electrodes to modulate the charge transfer efficiency of quantum dot-sensitized solar cells. The normalized PL intensity of TiO2/CuInS2 photo-electrodes had been obviously quenched with the as-prepared CuxS/GO composite hole transport layer, which had exhibited excellent charge separation properties of the solar cells. Due to the reduce of charge recombination traps under CuxS/GO composite hole transport layer, the charge transfer efficiency of the solar cells had been effectively improved. As a result, the higher Voc, FF and Jsc value can be obtained for TiO2/CuInS2 quantum dot sensitized solar cells with this CuxS/GO composite hole transport layer, which had exhibited the photovoltaic conversion efficiency enhancement from 4.85% to 6.07%. [ABSTRACT FROM AUTHOR]

A compact microwave bandpass filter with fishbone-shaped and hourglass-shaped groove structures based on substrate integrated plasmonic waveguide (SIPW) and spoof surface plasmon polariton (SSPP) is proposed and investigated. The dispersion and transmission characteristics of the proposed unit-cell structures of SSPP and SIPW were analyzed numerically, respectively. Numerical results indicate that the high and low cut-off frequencies of the bandpass filter can be independently adjusted by changing geometric parameters of unit-cell structures of SSPP and SIPW, respectively. The proposed microwave bandpass filter has a smaller electrical size because of its better electromagnetic (EM) field constraints than the traditional SIW ones with combed groove lines SSPPs. To verify the design method and concept, a microwave bandpass filter with fishbone-shaped and hourglass-shaped groove structures has been designed, fabricated, and measured. The results demonstrate that the proposed passband is in the range of 7.3–10.1 GHz, the return loss is higher than 10 dB and the insertion loss is less than 2 dB. The microwave bandpass filter is very compact in size, only about 0.99 λ0 × 0.35 λ0, where λ0 is the wavelength at the center frequency. [ABSTRACT FROM AUTHOR]

Grain boundary diffusion of TbF3 can improve the magnetic properties and thermal stability of NdFeB sintered magnets. The reducing agent CaH2 can effectively release reducing gas at high temperature, improve the atmosphere in the furnace. In this paper, the diffusion behavior and coercivity enhancement by printing (TbF3 + CaH2) pastes on the sintered NdFeB magnets was investigated. After diffusion, the coercivity increased rapidly from 15.7 to 28.4 kOe. Tb atoms diffuse first to the surface and then to the interior of the magnet, forming a network of Tb-rich shells around the Nd2Fe14B grains. The higher magnetic crystal anisotropy (Nd,Tb)2Fe14B phase determines the coercivity enhancement. This analysis was confirmed by FE-SEM and EDS observations of the microstructure and element distribution of the magnet. In addition, the effect of grain boundary diffusion on the remanence and thermal stability of the magnet was also studied. The results of this study have certain guiding significance for the preparation of sintered NdFeB magnets with high coercivity by diffusion technology. [ABSTRACT FROM AUTHOR]

The excellent thermal conductivity of graphite films makes it an ideal thermal management material in the field of electronics. Flexibility is an important property for preparing polyimide (PI)-derived graphite films with high thermal conductivity. In the study, hexagonal boron nitride (h-BN) was used as a foaming agent to improve the flexibility of PI-derived graphite films. A series of graphite films were prepared via carbonization and graphitization of self-synthesized polyimide films using h-BN as the foaming agent. The influence of different amounts of h-BN on the structure, flexibility, and thermal conductivity of graphite films was studied in detail. Compared with pure PI-derived graphite film, the flexibilities of h-BN/PI-derived graphite films improved significantly. The flexibility improvement mechanism of graphite film using h-BN as foaming agent was also proposed. The vaporization of BN powders at ultra-high temperature results in the pressure difference between inside and outside of the graphite layers, and then the graphitic "bubbles" were formed on the graphite film. The semicircular "bubbles" created by h-BN sublimation could provide enough adjustment space for the shear slip, and some of the forces around the pores could be partially offset. According to the results, the graphite film derived from the 0.06 wt% h-BN/PI composite film owe the best comprehensive performance, including excellent flexibility, relatively high thermal diffusivity and high in-plane thermal conductivity. This research has important application value in the field of heat dissipation of electronic devices. [ABSTRACT FROM AUTHOR]

Pixel x-ray detectors have been the working horse for the high resolution, high rate and high energy particle tracking for the past 20 years. In this paper, the (doped) poly-Si/SiOx is applied to heterojunction silicon pixel x-ray detectors. Ultrathin SiOx thin film of ~ 1.5 nm was prepared by wet chemical oxidation. Both P-type and N-type polycrystalline silicon (poly-Si) thin films were deposited on silicon oxide layer by APCVD to form the passivating contact on Si substrate. The influence of pixel size and the substrate thickness on the performance of pixel x-ray detectors was studied. The simulation results indicated that a thinner substrate was beneficial for the carrier transportation and collection. The experimental results showed that the leakage current turned large with increasing the pixel size. Whereas, the leakage current can be lowered by thinning the silicon substrate. Finally, the leakage current of 20 pA was achieved at room temperature for our 150 μm-large pixel x-ray detector and the energy resolution of 200 eV was obtained at 5.9 keV for the 305 μm-thick detector, which was better than that of detector on 525 μm substrate. The results suggested that good performance can be achieved for the pixel x-ray detector based on heterojunction on the thinned silicon substrate. [ABSTRACT FROM AUTHOR]

Water vapor inevitably existed in most purification and industrial processes which greatly influenced the efficiency. To understand the adsorption behavior of water at molecular level was desirable to elucidate the experimental observations. The work herein addressed the water adsorption on lignite-based activated carbon with consideration of two structural factors: surface oxidation and pore size. The results revealed that graphitic carbon was energetic unfavorable to water that the adsorption amount was less, and water molecules preferentially adsorbed near the defects in the carbon surface. The introduction of carbonyl functionalities changed the hydrophilic property of carbon which greatly increased the adsorption capacity. Water molecules firstly bounded to the functional groups with the separation distance of 2.77–3.11 Å, and small clusters merged with their neighbors to form larger clusters. The average distance of water mass centers was about 2.93–3.13 Å. The pore size distribution had less effect on the adsorption amount of water molecules; however, it significantly limited the size of cluster at higher relatively pressure (p/p0 = 0.7–0.9) in largely oxidized models (O atomic% = 12%). The largest cluster was consisted of 24–28 and 38–41 water molecules in microporous and micro-/mesoporous model, respectively. [ABSTRACT FROM AUTHOR]

In the present study, FeMnCrNiCo + 20 wt.%TiC laser cladding layer was heat-treated at 600 °C/750 °C/900 °C and held for 75 h. After heat treatment, the ceramic particles segregated at grain boundaries were precipitated homogenously by diffusion, which reduces the crack resistance sensitivity at the boundary and improved the elongation of the coating. At the same time, the diffusion of Ti and C elements at high-temperature results in the solid solution strengthening of the matrix metal, increasing the lattice distortion of FCC, and improving the micro-hardness and crack propagation resistance of the cladding layer. However, heat treatment of the cladding layer did not improve the spalling behavior of particles in the wear process, and the main wear mechanism was abrasive wear. [ABSTRACT FROM AUTHOR]

The microstructure and γ/γ′ interface misfit of a γ′-richen superalloy during a high-temperature thermal cycle (25–1200 °C) were studied. Then, the analytical models of the total elastic strain energy, plastic work, and mechanical driving force acting on the γ/γ′ interface with respect to misfit were derived to describe the elastic–plastic accommodation of the misfit strain during the thermal cycle. The cubic γ′ precipitate gradually dissolved when the temperature is higher than 900 °C. Tiny secondary γ′ phases precipitated from the supersaturated γ channel during the cooling stage. The lattice misfit was strongly dependent on the variation of the γ′ volume fraction during the thermal cycles. As the elastic–plastic accommodation of the misfit strain, the precipitation of the secondary γ′ had a significant influence on the stress field of the γ matrix. The total molar elastic strain energy first increased and then decreased, reaching a maximum of approximately 600 °C during the cooling stage. The plastic work increased significantly from 1100 to 900 °C, and the increasing trend became smaller when the temperature dropped from 900 to room temperature, which led to the plastic strain gradually accumulate during the cooling process. In addition, the elastic–plastic accommodation of the misfit strain inhibited the precipitation of the secondary γ′ in the cooling stage. [ABSTRACT FROM AUTHOR]

A series of vanadium nitride films were deposited by the magnetron sputtering system under different nitrogen to argon ratios. Results exhibited that the phase composition of the VN(Vanadium Nitride) films varies as the ratio of nitrogen to argon gradually increased from 1:10 to 10:10 as follows: VN + V → VN + V2N + V → VN + V2N; A single fcc-VN phase vanadium nitride film cannot be prepared under our magnetron sputtering preparation conditions. Phase composition and the interfacial growth pattern of different phases have a noticeable influence on the hardness of films. When the ratio of nitrogen to argon was 7:10, vanadium nitride film which is composed of VN phase, V2N phase and V phase gained the maximum hardness value of 22.4 GPa and VN(111) and V2N(110), VN(111) and V(110) were in a coherent relationship at the interface. [ABSTRACT FROM AUTHOR]

We fabricate CrP4 single crystal under high pressure and high temperature at 5 GPa and 1373 K. The comprehensive physical properties including electronic transport, magnetic properties, specific heat, Hall, thermal Seebeck and thermal conductivity are reported here. The resistivity shows a good metallic conductivity and T2.7 law relation in the low temperature, which indicates a weak correlation of electrons. It is interesting to note that CrP4 shows large magnetoresistance (MR) of 500% under T = 2 K and B = 9 T, and the MR does not reach saturation until 9 T. The mechanism of large MR in CrP4 is interpreted as the Fermi surface anisotropy. The Hall measurement shows that there is only one single type of carriers in CrP4 with holes. CrP4 exhibits paramagnetic behavior observed from the magnetic susceptibility measurement. Though CrP4 exhibits high electrical conductivity, unexpected low thermal conductivity is observed at low temperature, which is due to the zigzag chain of CrP6 octahedra along the c-axis. Low thermal conductivity is useful to design thermoelectric materials or devices by properly doping in CrP4. [ABSTRACT FROM AUTHOR]

33Na2O-40ZrO2-40SiO2-10P2O5 solid electrolytes were successfully prepared by the solid-phase reaction. The effects of sintering temperature and holding time on the crystal phase, microstructure, and electrical properties of the solid electrolytes were investigated by TG-DTG, X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectroscopy (IR), and electrochemical impedance spectroscopy (EIS). The results show that the main crystal phases of all the obtained solid electrolytes are Na3Zr2Si2PO12 of NASICON-type monoclinic structure, accompanied by a small amount of ZrO2 secondary phase. The sintering temperature and time have a significant effect on the microstructure of the materials but have little effect on the crystalline phases. The fine grain morphology and stable structure are beneficial to reduce the hindrance of ion conduction. These solid electrolytes sintered at 1200 °C for 15 h shows the highest room temperature ionic conductivity of 7.82 × 10–4 S·cm−1. At the same time, the good air stability of the solid electrolyte indicates that it has certain application prospects in the fields of gas sensors, portable electronic equipment, and so on. [ABSTRACT FROM AUTHOR]

Relaxor-based ferroelectric PZN-PT crystals are well known with excellent piezoelectric properties. However, the inhomogeneity has been usually observed in this system, which are closely related to its complicated domain structures and phase transitions. In this work, 0.91PZN-0.09PT crystals have been grown by the flux-Bridgman method. The evolution of the domain structures of (001) oriented wafers have been studied with the in situ observation using high-temperature polarized light microscopy. Both reversible and irreversible domains have been observed during the heating and cooling cycles between 25 and 250 °C. Especially, the unique irreversible domain evolutions are observed in the region which contains remaining monoclinic phase after the thermal cycles. The results indicate that the irreversible domains in PZN-PT crystal are possibly correlated to the remaining monoclinic phase which is frozen to room temperature during the thermal cycles. It may provide deeper insight into the intriguing mechanism of phase transition and domain evolutions for relaxor ferroelectrics. [ABSTRACT FROM AUTHOR]

In this work, competent hydrophobic/oleophilic fabric membranes for separating stratified oil–water mixtures were fabricated by a simple waterborne polymeric nanoparticle coating process by which the effective pore size and thickness of fabrics could be varied. Most importantly, a design of apparatus along with the data analysis for easy characterizing performance of the as-prepared fabric separation membranes was proposed. A membrane resistance, RM, to the Poiseuille flow of oil liquids driven by gravity was shown to adequately manifest a particular fabric separation membrane. Moreover, a fabric membrane with an as-determined value of RM was demonstrated to accomplish stratified oil–water separation in specific condition and enable the accurate prediction of separation time. In light of the fact, the estimation of mass flux and separation time of other Newtonian oil liquids through the hydrophobic/oleophilic membranes by this approach looks very promising. The simple yet useful methodology of this work illustrated its novelty in the field. [ABSTRACT FROM AUTHOR]

Fused deposition modeling provides an effective means for complex molding of Fe–Si–Al bonded magnets, but the fused deposition molding of Fe–Si–Al bonded magnets with high magnetic powder content is still a challenge. In this work, we used a miniature single screw as a print head to study the magnetic properties, mechanical properties and microstructure properties of Fe–Si–Al bonded magnets with different magnetic powders content. Compared with the molded samples made of the same raw material, the overall performance of the bonded magnet is the best. The Fe–Si–Al bonded magnets show a saturation magnetization of 123 emu/g and an ultimate tensile strength of 11.2 MPa. Moreover, its performance is equivalent to that of the compressed sample with the same magnetic powder content when the magnetic powder content is 94 wt%. This research provides a method for the composite molding of Fe–Si–Al bonded magnets with high magnetic powder content and lays a technical foundation for the application of Fe–Si–Al bonded magnets. [ABSTRACT FROM AUTHOR]

All-solid-state lithium batteries are considered to be the most promising electrochemical energy storage equipment due to their high safety, high energy density, and simple structure. However, the preparation of solid electrolytes with high lithium-ion conductivity and superior electrode–electrolyte interface contact is the development needs. In this study, the electronic structures of garnet-type Li7La3Zr2O12 (LLZO) and Sb-doped LLZO electrolytes were investigated using the first-principles method based on density functional theory (DFT). Theoretical calculations have confirmed that elemental doping facilitates the migration of lithium ions in solid-state electrolytes at the micro-atomic level. Based on the theoretical calculations and analysis results, Li6.7La3Zr1.7Sb0.3O12 (LLZSbO) with high ionic conductivity was synthesized by the conventional solid-state method. To reduce the interfacial impedance between electrolyte and electrode, the composite solid electrolytes (CSEs) containing LLZSbO active fillers were prepared by the solution casting method. The prepared CSEs exhibits a high ionic conductivity of 0.97 × 10–4 S cm−1 at 30 °C and a stable electrochemical window of 5.3 V as well as the lithium-ion transference number up to 0.37. The all-solid-state battery using the CSEs prepared with 20 wt% LLZSbO has excellent rate performance and cycle stability. The initial discharge specific capacity can reach 148.4 mAh g−1 when the rate is 0.1 C. The capacity can cover 138.8 mAh g−1 after 100 cycles at 0.2 C with a capacity retention rate of 97.5%. [ABSTRACT FROM AUTHOR]

Under alkaline conditions, thioglycollic acid (TGA)–CdTe quantum dots were prepared using hydroxylamine hydrochloride to reduce sodium tellurite in aqueous phase. The effects of n(Te2−)/n(HONH3Cl), reflux temperature, n(TGA)/n(Cd2+), and reflux time on the properties of the CdTe quantum dots were investigated to determine the optimum synthesis conditions. The structure and properties of the CdTe quantum dots were characterized via X-ray powder diffraction, photoluminescence spectrometry, and UV–Vis absorption spectrometry. Results showed that the CdTe quantum dots synthesized herein were cubic crystals, and the maximum fluorescence emission wavelength could be adjusted from 520 to 570 nm. Under the optimum conditions, the fluorescence quantum yield of the CdTe quantum dots reached 46.57% at reflux for 1 h. [ABSTRACT FROM AUTHOR]

An optimal annealing condition (360 °C, 10 min) was found for the FeBSiC Metglas, at which the Metglas transformed into a mix phase structure between amorphous and crystalline. It gives a deformation of single-layer FeBSiC Metglas ribbon increases from 26.9 ppm of the unannealed sample to 34.6 ppm, piezomagnetic coefficient d33,m from 1.9 to 2.6 ppm/Oe, and the loss decreases from 0.18 to 0.07%. After the mix phase Metglas and Mn-doped 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (Mn-doped PMN-PT) single crystal were fabricated into a magnetoelectric (ME) laminate composite, it is found that αQ at quasi-static and resonance frequency rises from 2183 to 2640 pC/Oe, and from 120,000 to 165,000 pC/Oe, with the increase amplitude of 21% and 37.5%, respectively. From test of realistic noise, the equivalent noise magnetic field (EMN) @1 Hz of the ME sensor made by mix phase Metglas declines from 20.2 to 15.4 pT/Hz1/2, and EMN@30 Hz from 1.46 to 1.23 pT/Hz1/2. The reinforcement of the piezomagnetic performance is attributed to the generation of mix phase structure. It can enhance ME coupling performance at quasi-static and resonance state, reduce loss, and boost the sensitivity of the ME sensor. [ABSTRACT FROM AUTHOR]

Flexible electronics is one of the most emerging fields of future electronic devices. The application of flexible inorganic membrane provides a feasible way to realize high-performance electronic device with desired deformation ability. In this paper, a method to fabricate large-scale flexible monocrystalline silicon membrane by crystal-ion-slicing (CIS) technique using benzocyclobutene (BCB) bonding layer is reported. With introduction of BCB bonding layer, a 1-μm-thick Si membrane with the size of 8 × 8 mm can be obtained on the polyimide substrate using the conventional CIS technique. Morphology and structure characterizations confirm the high crystallinity and structural integrity of the as-fabricated silicon membrane. Typical piezoresistive effect can be observed in the measured dependence of the resistance of Si membrane on the bending strain, indicating the potential to using this method to construct flexible force sensor with high stability and sensitivity. [ABSTRACT FROM AUTHOR]

Printed circuit board (PCB) fabrication technology has been widely used in metasurfaces in microwave domain. However, such technology still needs a non-negligible fabricating period and cost. To further explore the ultra-low-cost, convenient processing and fast demonstrating method, we present a metasurface using silver ink to produce the digital patterns for abundant scattering field manipulation. By directly painting the conductive ink on the paper to establish the specific metal structure, arbitrary EM properties can be designed, which could be regarded as a manually convenient PCB technology for metasurface fabrication. We design eight coding sequences to, respectively, generate single- and dual beam fields with different scattering angles. Simulations and measurements show good agreements, verifying the feasibility of our design method. We believe the presented metasurface processing method will promote the interests on flexible metasurface design and further stimulate related domain like wireless communication. [ABSTRACT FROM AUTHOR]

Tm3+ doped YAlO3 (Tm:YAP) crystals with different concentrations were grown successfully by Czochralski method. The full width at half maximum of 0.007–0.008° shows high crystalline quality. The shape of dislocation etching pit is consistent with its crystal structure. The absorption spectra show an intensive peak located at 794 nm. The fluorescence lifetimes of 6.06, 4.68, 4.22, 4.01, and 1.93 ms decrease monotonically with the increase of Tm3+ concentration in the range of 2–7.5 at%. The fluorescence spectra exhibit two strong peaks appeared near 1775 and 1853 nm, respectively. Among them, the 4 at.% Tm:YAP crystal possesses the largest fluorescence intensity at 1853 nm, indicating that it is a promising gain material operated at ~ 1.9 μm for the development of diode-pumped solid-state lasers and the dopant concentration larger than 4 at.% may cause decline in laser performance owing to larger reabsorption loss and higher nonradiative decay rate. [ABSTRACT FROM AUTHOR]

In this report, two-dimensional (2D) bismuth selenide (Bi2Se3) nanosheets (NSs) and reduced graphene oxide (rGO) (Bi2Se3/rGO) composites have been prepared via a hydrothermal method. The microstructures and morphology properties of Bi2Se3/rGO composites were analyzed by scanning electron microscopy (SEM) and Raman spectra, indicating a well prepared and high crystalline material. Photoelectrochemical (PEC) tests demonstrate that Bi2Se3/rGO heterojunction exhibits enhanced photocatalytic performance of the pure Bi2Se3, which is about five times higher than Bi2Se3 NSs, which is because rGO acts as a conduction pathway, resulting in efficient separation of photogeneration of electron–hole pairs on the Bi2Se3/rGO composites. The as-prepared composite provides a novel insight in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

Crystal ion slicing (CIS) technology has been widely applied to fabricate single-crystalline quality thin film, although the ion implantation process can cause lattice strain and electric properties changes in the fabricated film. In this paper, CIS-fabricated Z-cut LiTaO3 (LT) thin films were annealed under different temperatures and times by rapid thermal annealing (RTA). The effects of annealing parameters on microstructure and dielectric properties of LT films were studied. It is found that the lattice strain can be partially released by RTA according to the XRD diffraction peak shift and this lattice release also has an influence on the permittivity and dielectric loss. Additionally, anomalous recrystallization behavior has been observed in the samples annealed at higher temperature or longer time according to the abnormal grain growth revealed by AFM. Besides, unusual permittivity and dielectric loss increase in sample annealed at 600℃ was measured and it may result from the abnormal grain growth. In summary, it is indicated by the results that RTA is an effective way to release lattice strain and it can impact electric properties of CIS-fabricated LT thin film. [ABSTRACT FROM AUTHOR]

Because of the special low-dimensional physical properties of quantum dots (QDs) and the excellent optoelectronic properties of perovskite, the combination of perovskite solar cells (PSCs) and QDs may largely be one of the breakthroughs in device performance. However, little attention has been paid to the effect of the size of QDs on device performance except for bandgap tuning. In this work, non-toxic SnS QDs of different sizes were prepared by varying the reaction temperature of the thermal injection method. Their optical bandgaps with sizes were investigated, and they were implanted into the active layers of the carbon-based PSCs without hole transport layer. The effects of implanting SnS QDs with different sizes on the perovskite film quality and PSCs performance were studied. The cells implanted with SnS QDs of the best size (average 6.9 nm) achieved a photoelectric conversion efficiency of 14.26%, reaching a 12.42% improvement. The improved performance was mainly attributed to the presence of SnS QDs, which provided more nucleation sites for the growth of perovskite grains, and contributed to better quality perovskite films (including higher crystallinity, increased grain numbers and fewer surface defects), thus improving the light utilization, accelerating carrier transfer and reducing carrier recombination in the active layers. The successful implantation of QDs with different sizes in this paper has facilitated the development of the combination of perovskite and QDs in mesoporous PSC. [ABSTRACT FROM AUTHOR]

The growth and design of hyperbranched hierarchical nanoarchitectures attract considerable current research enthusiasm in various scientific and technological fields, in which high porosity, large surface area and strong coupling between the sub-branches, are expected. In this paper, the growth of hierarchical ZnOHF nanoarchitectures via a hydrothermal strategy is demonstrated. A variety of controllable morphologies with tunable degrees of branching, such as nanoparticles, nanorods, polypods, sheaf- and spherulite-like prickly hierarchical nanoarchitectures, can be obtained with the controlled regulation of the synthetic parameters including temperature, reaction time and solvent component. For the formation of ZnOHF hierarchical nanoarchitectures, the crystal splitting growth mechanism plays the dominant role, which is evidenced by the time-dependent morphological evolution. It is shown that the gas sensing properties of ZnOHF hyperbranched hierarchical nanoarchitectures may be closely correlated with their branching degrees. The half-sheaf-shaped ZnOHF nanoarchitecture exhibits the highest response for ethanol among some common hazardous volatile compounds. [ABSTRACT FROM AUTHOR]

The dielectric function of phase-change materials (PCMs) presents a tremendous difference for the amorphous and crystalline states. Therefore, the measurement of the mid-infrared transparency of thin films of PCMs will provide a cost-efficient method to reveal the dependence of amorphous-crystalline phase transition on their compositions. Although Sb–Te–Se system has shown the advantages of the high speed, low power consumption and long retention life, the information on the mid-infrared transparency of Sb–Te–Se thin films is still insufficient. In our investigation, combinatorial materials libraries of Sb–Te–Se thin films were synthesized. The composition and mid-infrared spectral transmittance of each pixel of Sb–Te–Se thin film in the library were characterized using the energy dispersive X-ray analysis (EDX) and Fourier-transform infrared (FTIR) spectrometer, respectively. The in-depth chemical composition for randomly selected pixels was identified using secondary ions mass spectroscopy (SIMS). The crystallographic structure of some pixels was also identified using micro-area X-ray diffraction (μ-XRD). It can be found that, with the change of composition in Sb–Te–Se thin films, their mid-infrared spectral transmittance can be organized into three distinctive groups, corresponding to amorphous Sb–Se, Sb2Se3 orthorhombic structure and Sb2Te3 rhombohedral structure, respectively. Therefore, the amorphous-crystalline phase transition and the phase-change from the orthorhombic structure of Sb2Se3 to the rhombohedral structure of Sb2Te3 can be completely reflected in the mid-infrared spectral transmittance of Sb–Te–Se thin films. [ABSTRACT FROM AUTHOR]

In this work, the thermodynamic properties of TMAl (TM = Ni, Fe, Ti) compounds were studied at a temperature of 0–1000 K and a pressure of 0–40 GPa through first principles based on density functional theory. The thermal expansion coefficient α and Debye temperature (θD) is sensitive to temperature and pressure. The single crystal elastic constants and polycrystalline elastic properties were calculated by the stress–strain method and Voigt–Reuss–Hill approximation. By analyzing the elastic anisotropy index (AU, Acomp, Ashear, and A1, A2, A3) and the surface structure and projection of Young’s modulus, the anisotropy of TMAl compounds was discussed. In addition, the sound velocities, anisotropy of the sound velocities and the electronic structures were also discussed. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulation of the microstructure of hydrogenated amorphous silicon (a-Si:H) thin film with different substrate temperatures has been performed based on the Tersoff potential. The results showed that: the silicon thin film maintained amorphous structure in the substrate temperature range from 200 to 1000 K; high substrate temperature could smooth the surface. The first neighbour Voronoi polyhedron was dominated by the tetrahedron. When the substrate temperature increased, the content of tetrahedrons increased due to the transition from pentahedrons and hexahedrons to tetrahedrons. The change of the second neighbour Voronoi polyhedron could be classified into two cases: one case with low medium coordination number decreased as temperature increased, while the other one with high medium coordination number showed an opposite change tendency. It indicated that the local paracrystalline structure arrangement of the second neighbour atoms had been enhanced as substrate temperature rose. [ABSTRACT FROM AUTHOR]

For a thermoelectric application, the thermal conductivity, electrical conductivity and figure of merit of epoxy resin-based composites incorporated with carbon nanotubes and TiO are investigated in this paper. First, the composite is prepared with a solution blending method. Then, the structure, thermal and electrical conductivities are characterized with experimental methods. Finally, the thermal conductivity, electrical conductivity and figure of merit are discussed. Results turn out that with an increasing content of carbon nanotube fillers, there are different changing trends of thermal and electrical conductivities because of large difference between thermal and electrical contact resistances in the composite. With the increasing filler content, the electrical conductivity increases exponentially while thermal conductivity saturates to be a constant value. Due to the large ratio of electrical to thermal conductivities, the figure of merit with 8 wt% of fillers is more than 50 times larger than that with a low content of fillers. Our results confirm that the recently proposed concept of 'electron-percolation thermal-insulator' is a feasible way to enhance the figure of merit of a polymer composite. [ABSTRACT FROM AUTHOR]

A novel mixed laser crystal of Nd:GdLaNbO (Nd:GLNO) was grown successfully by conventional Czochralski method. The unit cell parameters were obtained by Rietveld refinement method. The density of the as-grown crystal was measured by Archimedean buoyancy method and calculated in theory. Absorption spectrum of Nd:GLNO crystal was recorded at room temperature, and 11 absorption peaks were assigned. The defects of Nd:GLNO crystal were revealed by using chemical etching method with phosphoric acid as etchant. The mechanical properties (including hardness, yield strength, elastic stiffness constant, fracture toughness and brittleness index) were systemically estimated based on Vickers hardness test. All these obtained results play a quite important role in further investigation of Nd:GLNO crystal. [ABSTRACT FROM AUTHOR]

We propose ultrathin planar chiral metamaterials (CMs) based on square split rings (SSRs), which can change linearly polarized (LP) electromagnetic (EM) wave to circularly polarized (CP) EM wave at will. The EM resonant properties of the proposed CMs including magnitude, phase, retrieved electromagnetic parameters, and chirality are demonstrated. According to the polarization property of the proposed CMs, a CP patch antenna using the proposed CMs is constructed. Placing the proposed CMs in the presence of a conventional LP patch antenna, the antenna polarization mode can be changed from LP mode to CP mode. The antenna performances are investigated numerically and experimentally. A simple method for realizing CP antenna is provided using the present CMs. It can be expected that the proposed CP antenna can be used in electronic reconnaissance and jamming, mobile communication, and global position system. [ABSTRACT FROM AUTHOR]

Nanostructured metal oxide thin films with a large specific surface area are preferable for practical device applications in energy conversion and storage. Herein, we report instantaneous (milliseconds) photonic synthesis of three-dimensional (3-D) nanostructured metal oxide thin films through the pulsed photoinitiated pyrolysis of organometallic precursor films made by chemical solution deposition. High wall-plug efficiency-pulsed photonic irradiation (xenon flash lamp, pulse width of 1.93 ms, fluence of 7.7 J/cm and frequency of 1.2 Hz) is used for scalable photonic processing. The photothermal effect of subsequent pulses rapidly improves the crystalline quality of nanocrystalline metal oxide thin films in minutes. The following paper highlights pulsed photonic fabrication of 3-D nanostructured TiO, CoO, and FeO thin films, exemplifying a promising new method for the low-cost and high-throughput manufacturing of nanostructured metal oxide thin films for energy applications. [ABSTRACT FROM AUTHOR]

SrTiO (STO) single crystal wafer was annealed in vacuum, and co-planar metal-insulator-metal structure of Pt/Ti/STO/Ti/Pt were formed by sputtering Pt/Ti electrodes onto the surface of STO after annealing. The forming-free resistive switching behavior with self-compliance property was observed in the sample. The sample showed switchable diode effect, which is explained by a simple model that redistribution of oxygen vacancies (OVs) under the external electric field results in the formation of n-n junction or n-n junction (n donated n-type semiconductor; n donated heavily doped n-type semiconductor). The self-compliance property is also interpreted by the formation of n-n/n-n junction caused by the migration of the OVs under the electric field. [ABSTRACT FROM AUTHOR]