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The data throughput in the von Neumann architecture-based computing system is limited by its separated processing and memory structure, and the mismatching speed between the two units. As a result, it is quite difficult to improve the energy efficiency in conventional computing system, especially for dealing with unstructured data. Meanwhile, artificial intelligence and robotics nowadays still behave poorly in autonomy, creativity, and sociality, which has been considered as the unimaginable computational requirement for sensorimotor skills. These two plights have urged the imitation and replication of the biological systems in terms of computing, sensing, and even motoring. Hence, the so-called neuromorphic system has drawn worldwide attention in recent decade, which is aimed at addressing the aforementioned needs from the mimicking of neural system. The recent developments on emerging memory devices, nanotechnologies, and materials science have provided an unprecedented opportunity for this aim.

It is known that the Kohn–Sham eigenvalues do not characterize experimental excitation energies directly, and the band gap of a semiconductor is typically underestimated by local density approximation (LDA) of density functional theory (DFT). An embarrassing situation is that one usually uses LDA+U for strongly correlated materials with rectified band gaps, but for non-strongly-correlated semiconductors one has to resort to expensive methods like hybrid functionals or GW. In spite of the state-of-the-art meta-generalized gradient approximation functionals like TB-mBJ and SCAN, methods with LDA-level complexity to rectify the semiconductor band gaps are in high demand. DFT-1/2 stands as a feasible approach and has been more widely used in recent years. In this work we give a detailed derivation of the Slater half occupation technique, and review the assumptions made by DFT-1/2 in semiconductor band structure calculations. In particular, the self-energy potential approach is verified through mathematical derivations. The aims, features and principles of shell DFT-1/2 for covalent semiconductors are also accounted for in great detail. Other developments of DFT-1/2 including conduction band correction, DFT+A-1/2, empirical formula for the self-energy potential cutoff radius, etc, are further reviewed. The relations of DFT-1/2 to hybrid functional, sX-LDA, GW, self-interaction correction, scissor’s operator as well as DFT+U are explained. Applications, issues and limitations of DFT-1/2 are comprehensively included in this review.

For a straddle-type monorail train gearbox, analyze the heating mechanism and heat transfer mode of each element in the gearbox, establish a heat transfer model of the gearbox, use empirical formula to calculate the heating power of each heating element, and use the flow field analysis to monitor it. Accurately calculate the convective heat transfer coefficient for the volume fraction of oil and gas in each cavity. Using the method of finite element simulation, the influence of different oil injection and large spiral bevel gear steering on the temperature field distribution of the gearbox is calculated and analyzed. The results show that when the large spiral bevel gear turns for a certain amount of time, the maximum temperature of each part of the gearbox at high oil level is higher than that at low oil level; When the amount of oil injection is constant, the temperature of each part in the reverse rotation of the large spiral bevel gear is higher than that in the forward rotation. This article provides the main reference for the prediction of the temperature field of the gearbox of the straddle monorail train and the improved design of the lubricating oil passage in the gearbox.

ABSTRACT.In order to visualize the applications of deep learning based intelligent vehicle in the real field vividly, especially in the unmanned cases in which it realizes the integration of various technologies such as automatic data acquisition, data model construction, automatic curve detection, traffic signs recognition, verification of the unmanned driving, etc. A M-typed Model intelligent vehicle that is embedded with a high-performance board from Baidu named Edge Board is adopted by this study. The vehicle is trained under the PaddlePaddle deep learning frame and Baidu AI Studio Develop platform. Through the autonomous control scheme design and the non-stop study on the deep learning algorithm, an intelligent vehicle model based on PaddlePaddle deep learning is here. The vehicle has the function of automatic driving on the simulated track. In addition, it can distinguish several traffic signs and make feedbacks accordingly.

We demonstrate DC-RF dispersion-free graded AlGaN channel transistor with an epitaxial passivation. The device used for this experiment was an AlGaN channel polarization-graded field effect transistor (PolFET) with Al-composition grading from 0% to 30%. We were able to reduce the dispersion to almost zero current collapse and zero knee-walkout for pulsed I–V up to 30 V drain quiescent bias condition with epitaxial passivation, compared to 8 V knee-walkout and 25% current collapse for PolFETs with traditional PECVD SiNx for the same measure conditions. We also report large signal power density and two-tone linearity for these devices up to X-band frequencies.

The numerical analysis software ABAQUS has been used to study the temperature field of an assembled steel-truss concrete hollow floor in this paper to simulate the assembled steel-truss concrete hollow floor under thermal coupling under the ISO-834 standard heating curve. The distribution principle of temperature field for different sections in the floor system has been obtained to provide a reference for the study of the mechanical properties of assembled steel-truss concrete hollow floor.

An Al0.75Ga0.25N/Al0.6Ga0.4N heterostructure field effect transistor with graded MBE-regrown contacts is designed, grown, and fabricated on AlN/sapphire substrate. Maximum drain current density (ID,max) of 460 mA mm−1 was obtained on transistors with gate length of 130 nm. The small signal measurement shows current/power gain cutoff frequency (fT/fmax) of 40 GHz/58 GHz, respectively. Parasitic resistance is found to be a significant factor limiting the frequency performance of the devices. The high frequency performance of devices with high Al concentration AlGaN channel demonstrate potential for high power and high frequency applications.

The light unflavoured meson $\eta/\eta^{\prime}$ decays are valuable for testing non-perturbative quantum chromodynamics and exploring new physics beyond the Standard Model. This paper describes a series of event generators, including $\eta/\eta^{\prime}\to\gamma l^{+}l^{-}$, $\eta/\eta^{\prime}\to\gamma \pi^{+}\pi^{-}$, $\eta^{\prime}\to\omega e^{+}e^{-}$, $\eta\to\pi^{+}\pi^{-}\pi^{0}$, $\eta/\eta^{\prime}\to\pi^{0}\pi^{0}\pi^{0}$, $\eta^{\prime}\to\eta\pi\pi$ and $\eta^{\prime}\to\pi^{+}\pi^{-}\pi^{+}\pi^{-}/\pi^{+}\pi^{-}\pi^{0}\pi^{0}$, which have been developed for investigating $\eta/\eta^\prime$ decay dynamics. For most of these generators, their usability has been validated in BESIII analyses for determining the detection efficiency, and background studies. The consistency between data and Monte Carlo shows that these generators work well in the BESIII simulation, and will also be useful for ongoing BESIII analyses and other experiments for studying $\eta/\eta^\prime$ physics.

This paper studies the harmonic generation of the hydrogen atom subjected to a collinear bichromatic laser field by numerically solving the time-dependent Schrodinger equation using the split-operator pseudo-spectral method. By adding a frequency variation to the additional field, the contributions of different pathways to particular order harmonic generation can be isolated. The quantum interference pattern between harmonic pathways, which influences the harmonic intensity, is found to be either constructive or destructive with respect to different relative phase of the two field components. Detailed description of up to the 35th-order harmonics and the harmonic pathways for a wide range of field parameters is presented.

A pseudospectral method with symplectic algorithm for the solution of time-dependent Schrodinger equations (TDSE) is introduced. The spatial part of the wavefunction is discretized into sparse grid by pseudospectral method and the time evolution is given in symplectic scheme. This method allows us to obtain a highly accurate and stable solution of TDSE. The effectiveness and efficiency of this method is demonstrated by the high-order harmonic spectra of one-dimensional atom in strong laser field as compared with previously published work. The influence of the additional static electric field is also investigated.

A B-spline with the symplectic algorithm method for the solution of time-dependent Schrodinger equations (TDSEs) is introduced. The spatial part of the wavefunction is expanded by B-spline and the time evolution is given in a symplectic scheme. This method allows us to obtain a highly accurate and stable solution of TDSEs. The effectiveness and efficiency of this method is demonstrated by the high-order harmonic spectra of one-dimensional atoms in comparison with other references.

We investigate high-order harmonic generation (HHG) in a linearly polarized bichromatic field composed of a fundamental laser field with frequency ω and an additional laser field with frequency 3ω. The numerical results show that it is possible to enhance the intensity of most high harmonics in orders of magnitude. A most striking feature in the enhancement is that the intensity of several special high harmonics is practically impaired as compared with that in the monochromatic case. The qualitative explanation to the great enhancement is that the additional high-frequency field can provide new transition paths for electrons to reach the continuum. The relative phase between the fundamental field and its third harmonic field also affects the intensity of high-order harmonics near the cutoff efficiently.

Energies and wavefunctions of low-lying states and Rydberg states for the sodium atom in uniform magnetic fields varying from 0 to 105T are calculated using a pseudospectral approach with a model potential in spherical coordinates. The energies are comparable with experimental results as well as those obtained by other calculations. The spectra of oscillator strength are worked out. The evolution of them with the magnetic field is shown.

A B-spline method has been used to calculate the electron structure of endohedrally confined hydrogen-like atoms. The boundary conditions were conveniently satisfied with such the method. The evolution of the energy spectrum, as function of the depth of the confining well, exhibits a "mirror collapse". Ions with higher ionicity have more "collapse lines", the energies change more sharply at "collapse points", and the oscillator strengths change more violently with the depth of the confining well.

The B-spline basis set method is used to, study the properties of helium confined endohedrally at the geometrical centre of a fullerene. The boundary conditions of the wavefunctions can be simply satisfied with this method. From our results, the phenomenon of ''mirror collapse'' is found in the case of confining helium. The interesting behaviors of confining helium are also discussed.

A new pseudospectral method was introduced to calculate wavefunctions and energy levels of hydrogen atom in arbitrary potential. Some results of hydrogen atom in uniform magnetic fields were presented, high accuracy of results was obtained with simple calculations, and our calculations show very fast convergence. It suggests a new method for calculations of hydrogen atom in external fields.

We have calculated the energy levels of a hydrogen atom confined off-centre in an impenetrable spherical box using a linear variational method. Both the radial and angular wavefunctions are expanded in terms of B-splines. The validity of the approach has been examined for various off-centre distances. Comparison with other results given in the literature is made and consistent agreement is achieved. The change of the features of the energy levels in accord with the off-centre distance is revealed.

The annealing and etching effects of Pt/Bi3.15Nd0.85Ti3O12/Pt ferroelectric capacitors were studied. Bi3.15Nd0.85Ti3O12 (BNdT) thin films were obtained by a sol–gel method. At an annealing temperature of 650 °C, BNdT films crystallized well in nitrogen atmosphere, but remained amorphous in oxygen atmosphere. For capacitor fabrication, Pt top layers were etched by ion beam etch (IBE) to form top electrodes, and the BNdT ferroelectric films were etched by reactive ion etch (RIE) utilizing two different gases: SF6 and HC2ClF4. Degradation was discovered after top electrode etching, and could be partly recovered by rapid thermal annealing in oxygen at 650 °C. RIE etching damage was not prominent in both groups, though SF6 etched group was a bit superior to HC2ClF4 group. Nevertheless, HC2ClF4 group became noticeable inferior to SF6 group after a furnace annealing in nitrogen at 650 °C for 40 min. This was attributed to the influence of hydrogen, which was induced by RIE process in HC2ClF4 group. Instead, when oxygen was employed as the atmosphere of furnace annealing, both groups finally possessed similar ferroelectric properties, namely the RIE etching damage in HC2ClF4 group had been recovered.

The effects of Pb doping, oxygen doping (δ = 0.1, 0.2, 0.4 and 0.5) and high pressure (4, 8, 15 and 20 GPa) on the electronic structure of Hg0.8Pb0.2Ba2Ca2Cu3O8+δ have been examined by the recursion method. Our calculations show that Pb doping only decreases the hole concentration slightly and oxygen doping increases the hole concentration monotonically and significantly as δ varies from 0 to 0.5, with each excess oxygen atom contributing about 1.7 holes to the CuO2 layers. The optimal δ is estimated to be around 0.4. The hole concentration increases initially with pressure but decreases as P > 8 GPa (i.e., dn/dP does change sign at similar 8 GPa). The suppressed Tc(P) by Pb substitution has to be described in the modified Neumeier's model.

The electronic structure of HgBa2Ca2Cu3O8+ delta with various delta (0, 0.12, 0.2 and 0.4) and pressures (ambient pressure, 5 GPa, 10 GPa and 20 GPa) has been calculated by the recursion method. Our results show that the electronic structure of this series is highly two dimensional with a large N(EF). The hole concentration of the CuO2 layers and N (EF) increase monotonically as delta increases from 0 to 0.4. We thus suggest that the ideal delta should be 0.4. With increasing pressure, the hole concentration increases further and EF rises. The relationship between Tc and pressure can be described by the same model of YBa2Cu3O7- delta .

The electronic structure of La1.85Sr0.15CuO4, as well as the two cases of substitution of Ga and Sn for Cu, has been studied by the recursion method. The change of hole concentration and the effective local magnetic moment have also been calculated. Our calculations show that Ga and Sn destroy the two-dimensional character of the CuO2 plane and lead to the disorder of the electronic structure, accompanied by the migration of electrons which causes the decrease of the hole concentration in the CuO2 planes. From our point of view, these changes may be responsible for the destruction of superconductivity of the Ga and Sn-doped systems.

A method suitable for two-electron systems in a range running from low to high fields is given. M-L = -1 triplet state of H- ion and He atom are used to introduce the new means. All the matrix elements in our calculations are formulated as products of simple, independent one-dimensional numerical integrals and analytic ones. As a result, lower energies compared to those obtained with spherical coordinates in low fields, and cylindrical coordinates in high fields are presented.

Based on the B-spline basis method, the properties of the helium atom confined inside an endohedral environment, such as buckminster fullerene, are studied. In our calculations, the endohedral environment is a parabolic potential well. In this situation, the phenomenon of "mirror collapse" is exhibited for energy levels of a confined helium atom. The "giant resonance" of oscillator strength of the dipole transition emerges with the variation of depth of the confining well. The physical mechanisms of these phenomena are analyzed in this paper.

A continuous liquid level sensor (LLS) based on an in-fiber Michelson interferometer is proposed and experimentally demonstrated. The in-fiber Michelson interferometer is formed by a single long period grating (LPG) together with a reflective mirror at the end of the fiber. The portion between the mirror and LPG is immersed in the liquid to be measured as an LLS sensing probe, and the liquid level can be measured by monitoring the wavelength of interference fringes of the in-fiber Michelson interferometer. The experimental results show that the proposed LLS has a good sensing linearity and sensitivity.

Reactive ion etching (RIE) and ion beam etching (IBE) were used to etch the Bi3.15Nd0.85Ti3O12 (BNdT) ferroelectric layer and top electrode (TE), respectively, for ferroelectric random access memory (FeRAM) applications. The effect of dry etching on the ferroelectric properties of Pt/BNdT/Pt capacitors and the film etching mechanism were investigated. After TE etching, the remanent polarization (2Pr) of capacitors decreased through the charging effect, but was recovered by rapid thermal annealing (RTA). A distinct polarization suppression of the capacitors was observed after BNdT layer dry etching owing to the large amount of ions accumulated in the electrode/film interface and within the films. The property damage could be recovered after long-time furnace annealing. The capacitor property rejuvenation was complete even after 1010 switching cycles of fatigue test. The capacitor size effect and recovery of the ferroelectric properties after film etching process were also studied.

Lead zirconate titanate (PZT) fibers with diameters from 10?m to 40?m were prepared via a sol-gel route. Several kinds of chemicals were used, including lead acetate trihydrate, zirconium n-butoxide and titanium n-butoxide, in addition to butanol as a solvent. As a water source for hydrolysis reaction, Pb(CH3COO)2?3H2O was directly used without further adding of water or catalyst conventionally. Acetylacetonate and acetate were added as stabilization agents to obtain stable sols for fiber drawing. The gel-to-ceramic conversion was characterized with thermal analysis, infrared spectroscopy and X-ray diffraction. A pure perovskite phase was obtained after heat treatment at 650?C for 1h. By using scanning electron microscope (SEM), it was observed that a lower rate of heat treatment resulted in a denser microstructure of the fibers. The relative permittivity and the P-E hysteresis loop of the crystalline PZT fibers were also measured and discussed in the paper.

Phosphor of strontium aluminate co-actived by Eu2+ and Dy3+ is one kind of important afterglow luminescent materials. In this paper, the phosphors were used with transparent glaze for an inorganic luminous coating on the ceramic surface, which was stable even at high temperature. The chemical structure and microstructure of the luminous coating were identified with X-ray diffraction (XRD) and observed with scanning electron microscopy (SEM), respectively. The photoluminescence of the coating was measured by a HITACHI F-4500 fluorescence spectrophotometer. The afterglow property was recorded by a ST-86LA-3 brightness meter. The samples behaved good performances such as high lighting brightness and long after-glowing time.