Search

All-solid-state Z-scheme photocatalysts for overall water splitting to evolve H2 is a promising strategy for efficient conversion of solar energy. However, most of these strategies require redox mediators. Herein, a direct Z-scheme photoelectrocatalytic electrode based on a WO3-x nanowire-bridged TiO2 nanorod array heterojunction is constructed for overall water splitting, producing H2. The as-prepared WO3-x/TiO2 nanorod array heterojunction shows photoelectrochemical (PEC) overall water splitting activity evolving both H2 and O2 under UV–vis light irradiation. An optimum PEC activity was achieved over a 1.67-WO3-x/TiO2 photoelectrode yielding maximum H2 and O2 evolution rates roughly 11 times higher than that of pure TiO2 nanorods without any sacrificial agent or redox mediator. The role of oxygen vacancy in WO3-x in affecting the H2 production rate was also comprehensively studied. The superior PEC activity of the WO3-x/TiO2 electrode for overall water splitting can be ascribed to an efficient Z-scheme charge transfer pathway between the WO3-x nanowires and TiO2 nanorods, the presence of oxygen vacancies in WO3-x, and a bias potential applied on the photoelectrode, resulting in effective spatial charge separation. This study provides a novel strategy for developing highly efficient PECs for overall water splitting.

Here, in ionically conducting Na0.5Bi0.5TiO3 (NBT), we explore the link between growth parameters, stoichiometry and resistive switching behavior and show NBT to be a highly tunable system. We show that the combination of oxygen ionic vacancies and low-level electronic conduction is important for controlling Schottky barrier interfacial switching. We achieve a large ON/OFF ratio for high resistance/low resistance (RHRS/RLRS), enabled by an almost constant RHRS of ∼109 Ω, and composition-tunable RLRS value modulated by growth temperature. RHRS/RLRS ratios of up to 104 and pronounced resistive switching at low voltages (SET voltage of

In2O3 is a wide bandgap oxide semiconductor, which has the potential to be used as an active material for transparent flexible electronics and UV photodetectors. However, the high concentration of unintentional background electrons existing in In2O3 makes it hard to be modulated by the electric field or form p-n heterojunctions with a sufficient band-bending width at the interface. In this work, we report the reduction of the background electrons in In2O3 by Mg doping (Mg-In2O3) and thereby improve the device performance of p-n diodes based on the NiO/Mg-In2O3 heterojunction. In particular, Mg doping compensates the free electrons in In2O3 and reduces the electron concentration from 1.7 × 1019 cm-3 without doping to 1.8 × 1017 cm-3 with 5% Mg doping. Transparent p-n heterojunction diodes were fabricated based on p-type NiO and n-type Mg-In2O3. The device performance was considerably enhanced by Mg doping with a high rectification ratio of 3 × 104 and a remarkable high breakdown voltage of >20 V. High-resolution X-ray photoelectron spectroscopy was used to investigate the interfacial electronic structure between NiO and Mg-In2O3, revealing a type II band alignment with a valence band offset of 1.35 eV and a conduction band offset of 2.15 eV. A large built-in potential of 0.98 eV was found for the undoped In2O3 but decreased to 0.51 eV for 5% Mg doping of In2O3. The NiO/Mg-In2O3 diodes with an improved rectification ratio and wider depletion region provide the possibility of achieving photodetectors with rapid photoresponse.

The Auger recombination in bulk semiconductors can quickly depopulate the charge carriers in a nonradiative way, which, fortunately, only has a detrimental impact on optoelectronic device performance under the condition of high carrier density because the restriction arising from concurrent momentum and energy conservation limits the Auger rate. Here, we surprisingly observed enhanced Auger recombination in an α-Fe2O3 single crystal, a wide bandgap semiconductor with low carrier mobility. The Auger process was ascribed to the Coulombically coupled self-trapped excitons (STEs), and the relaxation of momentum conservation due to the strong spatial localization of these STEs should account for the enhancement. The STE-density dependent kinetics suggested that the strong polaronic effect could cause a micro-heterogeneous distribution of STEs in a high-quality bulk single crystal, which also gave rise to the micro-heterogeneous annihilation dynamics, and a stochastic recombination model was developed and successfully described the STE annihilation dynamics.

This paper presents the results from the furnace tests conducted on two assembled monolithic hollow-ribbed (AMH) slabs consisting of the open box and the covered box, respectively. Detailed experimental data in the form of describing slab cracking or spalling, furnace temperatures, temperature distributions, and vertical deflections are presented. Comparison of the results from the two fire tests indicates that the covered box shows better fire resistance compared to the open box; thus, the covered box is recommended to adopt in structural fire-resistant design. However, they are both prone to cracking or spalling at their bottom surfaces during the fire tests, so the AMH slab still needs further optimum design to meet its requirements of fire resistance and service function. In addition, the sealing quality of congruent boxes also has a great influence on the fire resistance of the AMH slab.

Organic–inorganic hybrid perovskite solar cells have attracted tremendous attention in photovoltaic research, but the presence of massive parasitic traps at the grain boundaries in perovskite films discourages efficient bimolecular recombination and carrier dynamics, which limits device performance and stability. Here we report a simple and fast chemical sintering protocol to substantially reduce grain boundary defects for as-formed films for different PbI2-templated perovskite materials. With this method parasitic traps on grain boundaries are intrinsically reduced, featuring the Urbach energy reduced by 1.5 meV. For optimal photovoltaic devices, we demonstrate a planar solar cell with power conversion efficiency (PCE) of 19.68% which retains 80% of this efficiency over 720 h in ambient air without any encapsulation. These findings offer a widely applicable, versatile process to efficiently reduce grain boundary defects and will be of interest to many other film material systems afflicted by polydispersity and grain boundary disturbances.

Fully-hydrogenated germanene, named germanane, represents a new nanostructured material for a variety of potential applications, such as electronics and optoelectronics. However, a critical requirement for developing practical and reliable electronic devices based on germanane consists of achieving a flexibly controllable charge carrier and doping level. Different to the conventional doping methods such as ion implantation and diffusion, by first-principles calculations we demonstrate that tetracyanobenzene (TCNB) molecular adsorption could introduce effective p-type doping in germanane due to the combination of germanane with electroactive acceptor molecule TCNB. The corresponding energy difference between the empty band minimum of the dopant and the valence band maximum for electron excitation is 0.173 eV. More importantly, this nondestructive p-type doping could be linearly tuned under an external E-field. Analysis of charge transfer by means of the equivalent capacitor model and the shift of energy levels in the superstructure of germanane/TCNB further reveals that the superposition of the external E-field and molecular adsorption-induced internal E-field plays a key role in the charge transfer between TCNB and germanane, especially in achieving a controllable p-type molecular doping level in germanane. Such convenient and flexible E-field-engineering of p-type molecular doping in germanane would be very helpful for potential applications of germanane-based electronic and optoelectronic devices in the future.

Interfacial charge transfer from silicon to heterogeneous catalysts plays a key role in silicon-based photoelectrochemical systems. In general, prior to interfacial charge transfer, carriers that are generated by photons with energies above the bandgap dissipate the excess kinetic energy via hot-carrier cooling, and such energy loss limits the maximum power conversion efficiency. The excess energy of hot-carriers, however, could be utilized through hot-carrier transfer from silicon to the catalysts, but such hot-carrier extraction has not yet been demonstrated. Here, we exploit transient reflection spectroscopy to interrogate charge transfer at the interface between silicon and platinum. Quantitative modeling of the surface carrier kinetics indicates that the velocity of charge transfer from silicon to platinum exceeds 2.6 × 107 cm s-1, corresponding to an average carrier temperature of extracted carriers of ∼600 K, two times higher than the lattice temperature. The charge transfer velocity can be controllably reduced by inserting silica spacing layers between silicon and platinum.

Organic-inorganic perovskite solar cells have attracted significant attention due to their remarkable performance. The use of alternative metal-oxide charge-transport layers is a strategy to improving device reliability for large-scale fabrication and long-term applications. Here, we report solution-processed perovskite solar cells employing nickel oxide hole-extraction layers produced in situ using an atmospheric pressure spatial atomic-layer deposition system, which is compatible with high-throughput processing of electronic devices from solution. Our sub-nanometer smooth (average roughness of ≤0.6 nm) oxide films enable the efficient collection of holes and the formation of perovskite absorbers with high electronic quality. Initial solar-cell experiments show a power-conversion efficiency of 17.1%, near-unity ideality factors, and a fill factor of >80% with negligible hysteresis. Transient measurements reveal that a key contributor to this performance is the reduced luminescence quenching trap density in the perovskite/nickel oxide structure.

Bismuth ferrite BiFeO3 (BFO) is an important ferroelectric material for thin-film optoelectronic sensing and potential photovoltaic applications. Its relatively large band gap, however, limits the conversion efficiency of BFO absorber-based PV devices. In this study, based on density functional theory calculations we demonstrate that with well-designed Fe-site elemental substitution, tetragonal BFO can exhibit a much lower fundamental band gap than that of conventional rhombohedral BFO without forming in-gap electronic states and unravelling the underlying mechanisms. Cation atomic size, electronegativity, and crystallographic symmetry are evidenced as critical parameters to tailor the metal 3d–oxygen 2p orbital interactions and thus intrinsically modify the electronic structure, particularly, the shape and character of the valence and conduction band edges. With the reduced band gap, improved mobility, and uncompromised ferroelectric and magnetic ground states, the present results provide a new strategy of designing high symmetry BFO for efficient optoelectronic applications.

Understanding the energetics at the interface, including the alignment of valence and conduction bands, built-in potentials, and ionic and electronic reconstructions, is an important challenge in designing oxide interfaces that have controllable multifunctionalities for novel (opto-)electronic devices. In this work, we report detailed investigations on the heterointerface of wide-band-gap p-type NiO and n-type SrTiO3 (STO). We show that despite a large lattice mismatch (∼7%) and dissimilar crystal structure, high-quality NiO and Li-doped NiO (LNO) thin films can be epitaxially grown on STO(001) substrates through a domain-matching epitaxy mechanism. X-ray photoelectron spectroscopy studies indicate that NiO/STO heterojunctions form a type II “staggered” band alignment. In addition, a large built-in potential of up to 0.97 eV was observed at the interface of LNO and Nb-doped STO (NbSTO). The LNO/NbSTO p–n heterojunctions exhibit not only a large rectification ratio of 2 × 103 but also a large ideality fact...

Transition metal chalcogenides represent a class of the most promising alternative electrode materials for high-performance lithium-ion batteries (LIBs) owing to their high theoretical capacities. However, they suffer from large volume expansion, particle agglomeration, and low conductivity during charge/discharge processes, leading to unsatisfactory energy storage performance. In order to address these issues, we rationally designed three-dimensional (3D) hybrid composites consisting of ZnSe nanodots uniformly confined within a N-doped porous carbon network (ZnSe ND@N-PC) obtained via a convenient pyrolysis process. When used as anodes for LIBs, the composites exhibited outstanding electrochemical performance, with a high reversible capacity (1,134 mA·h·g−1 at a current density of 600 mA·g−1 after 500 cycles) and excellent rate capability (696 and 474 mA·h·g−1 at current densities of 6.4 and 12.8 A·g−1, respectively). The significantly improved lithium storage performance can be attributed to the 3D architecture of the hybrid composites, which not only mitigated the internal mechanical stress induced by the volume change and formed a 3D conductive network during cycling, but also provided a large reactive area and reduced the lithium diffusion distance. The strategy reported here may open a new avenue for the design of other multifunctional composites towards high-performance energy storage devices.

Although two-dimensional (2D) semiconductors are the focus for next-generation field-effect transistors, it is still difficult to produce good, simple electrical contacts with these materials. The authors use density functional theory to study the Schottky-barrier height under the influence of a vertical external electric field, and demonstrate that NbS${}_{2}$ is a promising electrode for achieving $p$-type Ohmic contact with WSe${}_{2}$ and BP monolayers, with trivial dependence on external field. This suggests that with metallic NbS${}_{2}$ monolayer as the electrode, the influence of gate voltage on electrode-channel interfaces can be greatly suppressed, which has real impact on circuit design.

The geographical information, temporal and spatial distribution of pollution sources cannot be accurately described by the traditional aerosol lidar inversion data. In order to accurately locate the pollution sources and monitor the spatial and temporal distribution of pollutants, an aerosol lidar data visualization method based on ArcGIS is proposed in this paper. A natural neighborhood method is used to perform group interpolation on ArcGIS software, and the range range-extinction coefficient relationship diagram is plotted using the aerosol optical data obtained from Klett inversion algorithm. The geographic information is added to the lidar inversion data in this diagram. The aerosol spatial and temporal distribution range and the direction of aerosol diffusion are accurately displayed directly. The change of aerosol concentration is plotted in different colors, the visually displaying the concentration of pollutants in the detection area is realized. The aerosol detection data in the sunny and haze days in Yinchuan are visualized in this paper. The result shows that this method can quickly determine the geographical location of pollution sources and visualize the spatial and temporal distribution of aerosols. This method can be used to display aerosol data with geographic information for meteorological and environmental protection departments. This method can provide data support for meteorological and environmental protection departments to quickly determine the location and concentration of pollution sources.

This work reports a fundamental study on the electronic structure, optical properties, and defect chemistry of a series of Co-based spinel oxide ( Co 3 O 4 , ZnCo 2 O 4 , and CoAl 2 O 4 ) epitaxial thin films using x-ray photoemission and absorption spectroscopies, optical spectroscopy, transport measurements, and density functional theory. We demonstrate that ZnCo 2 O 4 has a fundamental bandgap of 1.3 eV, much smaller than the generally accepted values, which range from 2.26 to 2.8 eV. The valence band edge mainly consists of occupied Co 3 d t 2 g 6 with some hybridization with O 2 p /Zn 3 d , and the conduction band edge of unoccupied e g * state. However, optical transition between the two band edges is dipole forbidden. Strong absorption occurs at photon energies above 2.6 eV, explaining the reasonable transparency of ZnCo 2 O 4 . A detailed defect chemistry study indicates that Zn vacancies formed at high oxygen pressure are the origin of a high p -type conductivity of ZnCo 2 O 4 , and the hole conduction mechanism is described by small-polaron hoping model. The high p -type conductivity, reasonable transparency, and large work function make ZnCo 2 O 4 a desirable p -type transparent semiconductor for various optoelectronic applications. Using the same method, the bandgap of Co 3 O 4 is further proved to be ∼0.8 eV arising from the tetrahedrally coordinated Co 2 + cations. Our work advances the fundamental understanding of these materials and provides significant guidance for their use in catalysis, electronic, and solar applications.

Wide bandgap oxide semiconductors constitute a unique class of materials that combine properties of electrical conductivity and optical transparency. They are being widely used as key materials in optoelectronic device applications, including flat-panel displays, solar cells, OLED, and emerging flexible and transparent electronics. In this article, an up-to-date review on both the fundamental understanding of materials physics of oxide semiconductors, and recent research progress on design of new materials and high-performing thin film transistor (TFT) devices in the context of fundamental understanding is presented. In particular, an in depth overview is first provided on current understanding of the electronic structures, defect and doping chemistry, optical and transport properties of oxide semiconductors, which provide essential guiding principles for new material design and device optimization. With these principles, recent advances in design of p-type oxide semiconductors, new approaches for achieving cost-effective transparent (flexible) electrodes, and the creation of high mobility 2D electron gas (2DEG) at oxide surfaces and interfaces with a wealth of fascinating physical properties of great potential for novel device design are then reviewed. Finally, recent progress and perspective of oxide TFT based on new oxide semiconductors, 2DEG, and low-temperature solution processed oxide semiconductor for flexible electronics will be reviewed.

The cycloidal propeller for a Micro-Aerial Vehicle (MAV)-scale cyclogyro in hover was studied using a 2D Reynolds-averaged Navier-Stokes equations solver. The effects of the blade dynamic stall, parallel Blade Vortex Interaction (BVI), inflow variation and flow curvature were discussed, based on the results of numerical simulation. The results from the 2D Computational Fluid Dynamics simulation indicated that the blade of the cycloidal rotor is actually performing a pitching oscillation, if observed in a moving reference frame. The dynamic stall vortices shed from the upstream blade cause intense parallel BVI on the downstream blade. The interaction will induce upwash and downwash on the downstream blade. This changes the effective reduced frequency and actually delays the stall of the blade, which is beneficial to the thrust generation. There is also strong downwash in the rotor cage and it changes the inflow velocity experienced by the blade. The downwash and flow curvature can either be beneficial or harmful to the thrust generation. The combined effects of dynamic stall, parallel BVI, inflow variation and flow curvature cause large aerodynamic force peaks and ensure the cycloidal rotors work at very low rotation speeds with high thrust. This guarantees that the cycloidal rotors possess at least the same level of hover efficiency as screw propellers.

Very few industrial processes only produce the target product, but other materials not desired by the manufacturer are also obtained. These unwanted products constitute the residues of the processes and their discharge contributes to the overall environmental impact. The concept of preventing pollution is gaining increased importance, and certain industries that are particularly similar in nature, could benefit from PPP (Pollution Prevention Program) cross-fertilization. Implementing PPP sets important targets and benefits. A number of codes of good practice lead to PPP, both from a management and technical viewpoints. The fast development of technology and pollution standards implies important challenges for environmental engineers, environmental research and development. Although there is no general route to success, there are however a number of pollution prevention and waste reduction schemes that apply. These alternatives and procedures are illustrated in the paper. It is clear that environment-caring companies will be more readily accepted by their human environment. It is also evident that the engineer of the 21st century faces new and complex environmental challenges. Research remains the backbone of successful development.

Gallium oxide (Ga2O3) is an emerging wide bandgap semiconductor that has attracted a large amount of interest due to its ultra-large bandgap of 4.8 eV, a high breakdown field of 8 MV/cm, and high thermal stability. These properties enable Ga2O3 a promising material for a large range of applications, such as high power electronic devices and solar-blind ultraviolet (UV) photodetectors. In the past few years, a significant process has been made for the growth of high-quality bulk crystals and thin films and device optimizations for power electronics and solar blind UV detection. However, many challenges remain, including the difficulty in p-type doping, a large density of unintentional electron carriers and defects/impurities, and issues with the device process (contact, dielectrics, and surface passivation), and so on. The purpose of this article is to provide a timely review on the fundamental understanding of the semiconductor physics and chemistry of Ga2O3 in terms of electronic band structures, optical properties, and chemistry of defects and impurity doping. Recent progress and perspectives on epitaxial thin film growth, chemical and physical properties of defects and impurities, p-type doping, and ternary alloys with In2O3 and Al2O3 will be discussed.

© 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim There is current interest in finding nontoxic alternatives to lead-halide perovskites for optoelectronic applications. Silver–bismuth double perovskites have recently gained attention, but evaluating their carrier lifetime and recombination mechanisms from photoluminescence measurements is challenging due to their indirect bandgap. In this work, transient absorption spectroscopy is used to directly track the photocarrier population in Cs2AgBiBr6 by measuring the ground state bleach dynamics. A small initial drop is resolved in the ground state bleach on a picosecond timescale, after which the remaining photocarriers decay monoexponentially with a lifetime of 1.4 µs. The majority of the early-time decay is attributed to hot-carrier thermalization from the direct transition to the indirect bandgap, and the 1.4 µs lifetime represents the recombination of most photocarriers. From this lifetime, a steady-state excess carrier density of 2.2 × 1016 cm−3 under 1 sun is calculated, which is an order of magnitude larger than that for methylammonium lead iodide, suggesting that charge transport and extraction can be efficient in Cs2AgBiBr6 solar cells.

Transparent oxide semiconductors hold great promise for many optoelectronic devices such as transparent electronics, UV-emitting devices, and photodetectors. A p-n heterojunction is the most ubiquitous building block to realize these devices. In this work, we report the fabrication and characterization of the interface properties of a transparent heterojunction consisting of p-type NiO and n-type perovskite BaSnO3. We show that high-quality NiO thin films can be epitaxially grown on BaSnO3 with sharp interfaces because of a small lattice mismatch (∼1.3%). The diode fabricated from this heterojunction exhibits rectifying behavior with a ratio of 500. X-ray photoelectron spectroscopy reveals a type II or "staggered" band alignment with valence and conduction band offsets of 1.44 eV and 1.86 eV, respectively. Moreover, a large upward band bending potential of 0.90 eV for BaSnO3 and a downward band bending potential of 0.15 eV for NiO were observed in the interface region. Such electronic properties have important implication for optoelectronic applications as the large built-in potential provides favorable energetics for photo-generated electron-hole separation/migration.

Inefficient gas transport in the porous cathode is disastrous for the lithium–air battery to achieve a high electrochemical performance. Previous evaluation of the cathode diffusivity relies on indirect calculations based on multiple V–I data obtained over the intact battery system, which inevitably induces evaluation uncertainty and material waste. In this report, an electrochemical device is designed for the out-of-cell diffusivity measurement in the lithium–air battery with micro/nano-sized cathodes. With the measured diffusivity, a few electrochemical parameters including the limiting current density and the concentration polarization associated with the porous cathodes can thus be directly evaluated. The work facilitates the development of highly-efficient cathode materials in the general field of metal–air battery field.

The development of diabetic peripheral neuropathy (DPN) is always followed by changes in vascular endothelial cells that are related to the reactivity of the homocysteine (Hcy) sulfhydryl group. In this meta-analysis, we investigated the association of Hcy with the pathogenesis and progression of DPN. We screened the Embase, Ovid, PubMed, Web of Science, Wangfang, and China National Knowledge Infrastructure databases. All analyses were performed by using the STATA software, version 12.0 (StataCorp, College Station, TX, USA) and the Comprehensive Meta-analysis 2.0 software (Biostatic Inc., Englewood, NJ, USA). The standardized mean difference (SMD) and 95% confidence interval (95%CI) were further calculated. The electronic literature search identified six articles that included 603 patients with DPN and 687 healthy controls. The pooled SMD of those six studies revealed that increased serum levels of Hcy may be correlated with DPN (SMD = 1.23, 95%CI: 1.09-1.36, P < 0.001). Subgroup analysis according to ethnicity indicated that high serum Hcy levels might be an important risk factor for DPN in both Asian and Caucasian populations (Asians: SMD = 0.62, 95%CI: 0.45-0.79, P < 0.001; Caucasians: SMD = 2.32, 95%CI: 2.10-2.55, P < 0.001; respectively). Elevated serum levels of Hcy indicate the risk of development of DPN in patients, suggesting that Hcy levels could be used as a marker for new therapeutic approaches to DPN.

The aim of the present study was to study the effects of arachidonic acid (ARA) in a rat brain ischemia/reperfusion model induced by middle cerebral artery occlusion (MCAO). A total of 50 rats were randomly divided into five groups: control group, MCAO group, MCAO + ARA 0.3 g/kg group, MCAO + ARA 1 g/kg group, and MCAO + ARA 3 g/kg group. The MCAO + ARA groups received ARA by intraperitoneal injection daily for 14 consecutive days, while the rats in the control and MCAO groups were given equivalent volume of saline. We detected the Morris water maze test and pathological changes to investigate the ischemia/reperfusion injury. The protein levels of tumor necrosis factor-alpha and interleukin-6 in the hippocampus were detected by enzyme-linked immunosorbent assay kits. In addition, the activities of superoxide dismutase, glutathione peroxidase, and malondialdehyde were assayed in hippocampus homogenates to evaluate the oxidative stress after ischemia/reperfusion. The results indicated that ARA administration decreased biochemical parameters of inflammation and oxidative stress. Morris water maze test and histopathological examination further verified the protective effects of ARA on ischemia/reperfusion injury rats. These findings demonstrated that ARA could protect MCAO-induced brain injury rats by inhibition of inflammation and oxidative stress, suggesting that it may have potential as a therapy for cerebral ischemia/reperfusion injury.

Bismuth-based compounds have recently gained increasing attention as potentially nontoxic and defect-tolerant solar absorbers. However, many of the new materials recently investigated show limited photovoltaic performance. Herein, one such compound is explored in detail through theory and experiment: bismuth oxyiodide (BiOI). BiOI thin films are grown by chemical vapor transport and found to maintain the same tetragonal phase in ambient air for at least 197 d. The computations suggest BiOI to be tolerant to antisite and vacancy defects. All-inorganic solar cells (ITO|NiO x |BiOI|ZnO|Al) with negligible hysteresis and up to 80% external quantum efficiency under select monochromatic excitation are demonstrated. The short-circuit current densities and power conversion efficiencies under AM 1.5G illumination are nearly double those of previously reported BiOI solar cells, as well as other bismuth halide and chalcohalide photovoltaics recently explored by many groups. Through a detailed loss analysis using optical characterization, photoemission spectroscopy, and device modeling, direction for future improvements in efficiency is provided. This work demonstrates that BiOI, previously considered to be a poor photocatalyst, is promising for photovoltaics., National Science Foundation (U.S.) (Grant CBET-1605495), United States. Department of Energy. Office of Basic Energy Sciences (Grant DE-SC0001088), National Science Foundation (U.S.) (Grant DMF-08019762)

Ultrathin epitaxial films of ferromagnetic insulators (FMIs) with Curie temperatures near room temperature are critically needed for use in dissipationless quantum computation and spintronic devices. However, such materials are extremely rare. Here, a room‐temperature FMI is achieved in ultrathin La0.9Ba0.1MnO3 films grown on SrTiO3 substrates via an interface proximity effect. Detailed scanning transmission electron microscopy images clearly demonstrate that MnO6 octahedral rotations in La0.9Ba0.1MnO3 close to the interface are strongly suppressed. As determined from in situ X‐ray photoemission spectroscopy, O K‐edge X‐ray absorption spectroscopy, and density functional theory, the realization of the FMI state arises from a reduction of Mn eg bandwidth caused by the quenched MnO6 octahedral rotations. The emerging FMI state in La0.9Ba0.1MnO3 together with necessary coherent interface achieved with the perovskite substrate gives very high potential for future high performance electronic devices., Ultrathin ferromagnetic insulators with Curie temperatures above room temperature are critically needed for developing dissipationless quantum electronic and spintronic devices. Unfortunately, such materials are extremely rare in nature. Room‐temperature ferromagnetic insulating states are successfully synthesized by an interfacial octahedral proximity effect in ultrathin La0.9Ba0.1MnO3 films, which could serve as promising candidates for future oxide‐based electronic devices.

Epitaxial films of In(2)O(3) have been grown on Y-stabilised ZrO(2)(111) substrates by molecular beam epitaxy over a range of thicknesses between 35 and 420 nm. The thinnest films are strained, but display a 'cross-hatch' morphology associated with a network of misfit dislocations which allow partial accommodation of the lattice mismatch. With increasing thickness a 'dewetting' process occurs and the films break up into micron sized mesas, which coalesce into continuous films at the highest coverages. The changes in morphology are accompanied by a progressive release of strain and an increase in carrier mobility to a maximum value of 73 cm(2) V(-1) s(-1). The optical band gap in strained ultrathin films is found to be smaller than for thicker films. Modelling of the system, using a combination of classical pair-wise potentials and ab initio density functional theory, provides a microscopic description of the elastic contributions to the strained epitaxial growth, as well as the electronic effects that give rise to the observed band gap changes. The band gap increase induced by the uniaxial compression is offset by the band gap reduction associated with the epitaxial tensile strain.

Europium chalcogenides (EuX, X = O, S, Se, Te), a class of prototypical Heisenberg magnetic semiconductors, exhibit intriguing properties in optics, magnetism, and magneto-optics at the nanoscale, and have broad application potential in optical/magnetic sensors, spintronics, optical isolators, etc. EuX nanocrystals (NCs) exhibit enhanced properties, such as high saturation magnetization, a strong magneto-optic effect (Faraday rotation), and high magneto resistance, which are all unanimously dependent on the NC's size, shape, and surface information. In this report, we give an overview of the fundamental properties of bulk EuX, and illustrate the quantum confinement effects on the optical, magnetic and magneto-optical properties of EuX nanostructures. We then focus on doping and self-assembly-two efficient methods that enhance magnetic properties by manipulating magnetic coupling in EuX nanostructures. In particular, we look towards future research on Eu(2+) NCs, which along with the overview provides an up-to-date platform for evaluating the fundamental properties and application potential of Eu-based semiconductors.

A simulation procedure to examine the backscattering radar cross-section (RCS) of a hypersonic object with plasma sheath is presented. Computational fluid dynamics tool is adopted to resolve the distributions of electron density and atmospheric temperature, and then the complex dielectric constant of plasma sheath are found. Volume-surface integral equation method is employed to extract the backscattering RCS of the hypersonic object with plasma sheath. Numerical results show that the plasma sheath can absorb some electromagnetic waves at L-band and reduce the backscattering RCS almost in any direction. Also, the attack angle of the moving object influences the backscattering RCS for both vertical and horizontal polarization incidences.

A wireless sensor system powered by AM broadcast energy harvesting is presented. A 10 meter length horizontal antenna and a resonant circuit were combined to harvest the electromagnetic energy, in the frequency range from 531 kHz to 1602 kHz. In a typical urban environment, an output voltage up to 14 V and a power of 82 μ W were obtained by a single stage doubler rectifier. A seven-day measurement is implemented to verify the stability of the energy. The output characteristics, multi stage doubler rectifier and implementation of sensor prototype are also discussed. The results indicate that the energy carried by AM radio is sufficient to drive a basic wireless sensor operating in sleep/wakeup mode. The stability and continuity of the harvested energy is superior to solar energy.

Objectives Exenatide is an adjunctive treatment for Type 2 diabetes. This was the first study to evaluate the pharmacokinetics, safety and tolerability of therapeutic doses (5 microg and 10 microg) of exenatide after single and multiple subcutaneous injections in healthy adult Chinese subjects. Methods 24 healthy volunteers were randomized to receive either 5 microg or 10 microg of exenatide by subcutaneous injection. Subjects received a single injection of exenatide on Day 1, twice daily on Days 2 and 3, and once on Day 4. Serial blood samples were drawn for pharmacokinetic assessment at pre-dose and up to 12 h post dose on Day 1 and Day 4. Adverse events, vital signs, 12-lead ECG, body weight and clinical laboratory evaluations were assessed. Results Exenatide, 5 microg and 10 microg, was rapidly absorbed with a median tmax of 1 h after single and multiple doses. Exenatide Cmax and AUCtau,ss were (geometric mean (90% CI)) 145 (119 - 176) pg/ml and 370 (297 - 460) pg x h/ml, respectively, after multiple dosing with 5 microg. The Cmax and AUCtau,ss were 311 (271 - 357) pg/ml and 878 (785 - 983) pg x h/ml, respectively, for 10 microg. Mean half-life (t1/2, range 0.99 - 1.25 h), apparent volume of distribution (Vz/F, 19.2 - 22.3 l), and apparent clearance (CL/F, range 11.4 - 13.5 l/h) remained consistent between single and multiple doses and across the two dose levels. Both the accumulation ratios and linearity index approached 1.0. The most common adverse events were gastrointestinal in nature and mild in severity. The frequency of adverse events increased with dose, such that 8% of subjects who received 5 microg and 42% of subjects who received 10 microg experienced adverse events. Conclusions Exenatide was rapidly absorbed, with similar pharmacokinetic properties following single and multiple doses. Exenatide exposure after multiple doses approximately doubled from 5 microg to 10 microg.

In addition to the traditional re-entry warhead and re-entry capsule, more and more hypersonic objects appear in the near space in recent years, such as the X-51, X-37, and so on. Analysis of electromagnetic scattering properties of these objects has important values for identification, recognition, communication and control. Challenging problems to extract their scattering characteristics include at least three aspects: (2) Modeling of plasma sheath due to the hypersonic motion in the thin atmosphere of the near space. (2) Electrically large size of the object itself plus the surrounding non-uniform plasma region. (3) Doppler and micro-Doppler effects caused by the hypersonic translation and possible rations of the object as a whole about an apparent barycenter. In this talk, we will begin with the modeling of the plasma sheath by using computational fluid dynamics software such as the FASTRAN for hypersonic body. With the electron density and atmospheric temperature found by the software, we can calculate the electromagnetic parameters of the plasma region. Then, we will concentrate on analyzing the influences of the plasma sheath on the backscattering cross-sections. A hybrid approach by incorporating the rigorous moment method with the approximate Born iterative method is developed to mitigate the computing cost in solving the matrix equation. The scattering property analyses are performed in the object reference system, and relativity transforms are employed to convert the incident and scattering fields between the lab system and the object system. Finally, extracting methods for the Doppler and micro-Doppler frequencies are introduced, and possible applications of the Doppler and micro-Doppler parameters are discussed.

Epitaxial La1-x Srx CrO3 deposited on SrTiO3 (001) is shown to be a p-type transparent conducting oxide with competitive figures of merit and a cubic perovskite structure, facilitating integration into oxide electronics. Holes in the Cr 3d t2g bands play a critical role in enhancing p-type conductivity, while transparency to visible light is maintained because low-lying d-d transitions arising from hole doping are dipole forbidden.

This study aimed to explore serum adiponectin and osteoprotegerin levels in patients with coronary heart disease (CHD) and their correlation with inflammatory and ischemia factors. From September 2010 to Augest 2010, 347 CHD patients were enrolled for a retrospective analysis. Serum lipoprotein phospholipase A2 (Lp-PLA2), hypersensitive C-reactive protein (hs-CRP), ischemia modified albumin (IMA), and adiponectin and osteoprotegerin levels were detected and analyzed. Serum adiponectin levels (ng/mL, CV was 4.3% at 250 ng/mL) were found to be negatively correlated with Lp-PLA2 (r = -0.958, P = 0.014) and hs-CRP (r = -0.958, P = 0.015) and positively correlated with IMA (r = 0.962, P = 0.025). Serum osteoprotegerin levels were positively correlated with Lp-PLA2 (r = 0.933, P = 0.027) and hs-CRP (r = 0.932, P = 0.022) and negatively correlated with IMA (r = -0.924, P = 0.017). In addition, serum adiponectin levels negatively correlated with osteoprotegerin levels. In conclusion, serum adiponectin level was negatively correlated with CHD progression, whereas serum osteoprotegerin level was positively correlated with CHD progression. Combined detection of adiponectin and osteoprotegerin levels may be of potential value in the clinical determination of CHD severity.

Epitaxial La1-x Srx CrO3 deposited on SrTiO3 (001) is shown to be a p-type transparent conducting oxide with competitive figures of merit and a cubic perovskite structure, facilitating integration into oxide electronics. Holes in the Cr 3d t2g bands play a critical role in enhancing p-type conductivity, while transparency to visible light is maintained because low-lying d-d transitions arising from hole doping are dipole forbidden.

An automatic defect testing system is dealt with in this article. It includes two parts, defect feature extraction, and defect classification and sizing. Defect feature extraction is carried out by adaptive filter deconvolution. The time delay between two consecutive taps of the adaptive filter is one half cycle of the ultrasonic echo to be processed. Wideband ultrasonic defect echoes of center frequency 1.2 MHz generally have 2-4 cycles and 100-200 data points for a 50 MHz sampling rate. After deconvolution, data are reduced to 4-8 points, and the frequency bandwidth is greatly extended. As a result, the defect features stand out. The deconvolved defect echoes are presented to an artificial neural network (ANN) for automatic defect classification and sizing. Two application examples are given in this article, exact classification and reasonable sizing accuracy have been achieved.

Occupant Protection System (OPS) is a key component in today's vehicle systems to reduce occupant's injuries during collisions. To assess OPS performance under a wide variety of crash conditions, vehicle barrier tests, laboratory dynamic sled tests and computer simulations are the major tools for the systems development. As the main input to the system, vehicle crash pulse controls the OPS design. Its variations have significant impact on the overall system responses. A well-correlated MADYMO model is employed to evaluate the effects on a frontal OPS. A set of crash pulses are quantitatively analyzed to assess the sled repeatability. Statistical analyses are then performed to define the corresponding dummy dynamic response corridors. The results show that small crash pulse discrepancy could result in significant variations of dummy dynamic responses and injury measurements. This study has the potential to help design a robust occupant restraint system less sensitive to crash pulse variations.

Correction for ‘Electronic and transport properties of Li-doped NiO epitaxial thin films’ by J. Y. Zhang et al., J. Mater. Chem. C, 2018, 6, 2275–2282.

Transparent, conducting p-La1−xSrxCrO3 epitaxial layers were deposited on Nb-doped SrTiO3(001) by oxygen-assisted molecular beam epitaxy to form structurally coherent p-n junctions. X-ray photoelectron spectroscopy reveals a type II or “staggered” band alignment, with valence and conduction band offsets of 2.0 eV and 0.9 eV, respectively. Diodes fabricated from these heterojunctions exhibit rectifying behavior, and the I-V characteristics are different from those for traditional semiconductor p-n junctions. A rather large ideality factor is ascribed to the complex nature of the interface.

The use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials. The superior performance has been attributed to effective alleviation of surface charging. A simulated nuclear waste glass (SON68) and layered hole-perovskite oxide thin films were selected as model systems because of their fundamental and practical significance. Our results show that high sputter rates and accurate interfacial information can be achieved simultaneously for argon cluster sputtering, whereas this is not the case for cesium and oxygen sputtering. Therefore, the implementation of an argon cluster sputtering source can significantly improve the analysis efficiency of insulating materials and, thus, can expand its applications to the study of glass corrosion, perovskite oxide thin film characterization, and many other systems of interest.

Precise control over the morphology of one-dimensional (1D) nanostructures is an essential step in the effort to develop nano-devices with exotic properties. Here we demonstrate the formation of highly aligned In2O3 nanorod arrays on Y-stabilised ZrO2(110) grown by oxygen plasma assisted molecular beam epitaxy. The evolution of morphologies, strain and tilt in the In2O3 nanorods are studied by atomic force microscopy and high resolution synchrotron-based X-ray diffraction. It is shown that the preferential 1D growth is driven by minimization of the total surface and interface energies. The mismatch of ca. 1.7% between the substrate and the epilayer is accommodated by strain along the [110] direction coupled with tilting of the rods along [001] and [001] directions and contraction in the [110] direction. The present highly ordered In2O3 nanorod arrays supported on an insulating substrate are of potential interest for large-scale fabrication of nano-devices.

In this paper, some leaky-wave absorbent harmonic filters are presented that developed by NRIET which constructed by a primary rectangular waveguide and single, double, three series accessorial rectangular waveguide loads located at the wide or narrow face of the primary waveguide. The method of equivalent circuit is also presented to analyzed this type of waveguide leaky-wave harmonic filter. The tested results are also shown that all of the performances at pass band and stop band are all well.

Exercise is recognized as an activator to elicit an inflammatory response whilst moxibustion in traditional Chinese medicine has been previously found to modulate immune functioning. However, whether moxibustion can alleviate the inflammatory cytokines response to chronic exhaustive exercise remains unknown. In the present study, rats were randomly assigned to a sedentary control group (Sed), a sedentary moxibustion group (Sed + Moxa), and 2 trained groups- one submitted to a 3-week exhaustive swimming (Trained), and the other a trained moxibustion group (Trained + Moxa). We found that chronic exhaustive exercise significantly increased the serum levels of pro-inflammatory cytokines (IL-1 beta, TNF-alpha, IFN-gamma) and the IFN-gamma/IL-4 ratio, and decreased the anti-inflammatory cytokines (IL-4, IL-10). Moxibustion treatment markedly reduced the serum levels of IL-1 beta, IFN-gamma and the IFN-gamma/IL-4 ratio, while elevated the IL-4 and IL-10 productions in trained rats. However, TNF-alpha level was not significantly affected. Our results suggested that an excessive inflammatory response and a potential inflammatory damage may be involved during chronic exhaustive exercise. Moxibustion could attenuate the inflammatory impairment and have an anti-inflammatory effect. The beneficial effects of moxibustion might be mediated by reducing the pro-inflammatory cytokines, increasing the anti-inflammatory cytokines, and modulating the balance between pro- and anti-inflammatory cytokines.