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During a global pandemic, individual views of government can be linked to citizens' trust and cooperation with government and their propensity to resist state policies or to take action that influences the course of a pandemic. This article explores citizens' assessments of government responses to COVID‐19 as a function of policy substance (restrictions on civil liberties), information about performance, and socioeconomic inequity in outcomes. We conducted a survey experiment and analyzed data on over 7000 respondents from eight democratic countries. We find that across countries, citizens are less favorable toward COVID‐19 policies that are more restrictive of civil liberties. Additionally, citizens' views of government performance are significantly influenced by objective performance information from reputable sources and information on the disproportionate impacts of COVID‐19 on low‐income groups. This study reinforces the importance of policy design and outcomes and the consideration of multiple public values in the implementation of public policies. [ABSTRACT FROM AUTHOR]

This study sheds light on the effect of alumina on dielectric constant and dielectric loss of novel CaCu3Ti4O12 composite ceramics. Alumina, at several concentrations, was deposited on the surface of CaCu3Ti4O12 particles via sol-gel technique. The dielectric constant significantly increased for all frequencies and the dielectric loss substantially decreased for low and intermediate frequencies. These observations were attributed to the change in characteristics of grains and grain boundaries. It was found that the insulating properties of the grain boundaries are improved following the addition of Al2O3. The relative density of CaCu3Ti4O12/Al2O3 composite ceramics decreased compared to the pure CaCu3Ti4O12 and the grain size was greatly changed with the alumina content affecting the dielectric properties. With the addition of alumina into CaCu3Ti4O12 , tighter interfaces formed. The 6%- and 10%-alumina ceramics showed the minimum dielectric loss and the maximum dielectric constant, respectively. Both the dielectric constant and loss tangent decreased in the 20%-alumina ceramic due to the formation of CuO secondary phase. It was revealed that Al serves as an electron acceptor decreasing the electron concentration, if Al3+ ions substitute for Ti4+ ions, and as an electron donor increasing the electron concentration, if Al3 + ions substitute for Ca2+ ions. We established a processing-microstructure-properties paradigm which opens new avenues for novel applications of CaCu3Ti4O12/Al2O3 composite ceramics. [ABSTRACT FROM AUTHOR]

Atomic-scale [Fe/Pt]n multilayer films with different total thickness were prepared on thermally oxidized Si (100) substrates at room temperature by monatomic layer deposition using dc-magnetron and rf-magnetron sputtering. Effects of the total thickness on (001) texture, surface morphology, and magnetic properties of the postannealed films have been investigated. It is found that the particlelike structure films with perfect (001) texture and perpendicular magnetic anisotropy are obtained with a thickness of less than or equal to 6.5 nm. After 500 °C annealing, the films with thickness of 6.5 and 11.9 nm show very smooth surface. In addition, with increasing total thickness of the films, (001) texture and perpendicular magnetic anisotropy of the annealed films deteriorate, and the films become continuous in structure. The total thickness of the films also affects the exchange-coupling interaction among FePt magnetic grains and the magnetization reversal process. [ABSTRACT FROM AUTHOR]

The crystal structure and polarization switching behavior of SrBi1.4La0.6Ta2O9 (SBLT) thin films have been studied by x-ray diffraction and piezoresponse force microscopy (PFM), respectively. Compared with SrBi2Ta2O9 (SBT), SBLT thin films show a reduced orthorhombic distortion. The polarization rotation of SBLT thin film, which is driven by negative and positive direct current (dc) biases, has been investigated by a combination of vertical and lateral PFM (VPFM and LPFM, respectively). After dc bias applications, the VPFM image is hardly changed, whereas the LPFM image experiences an obvious variation. It is believed that such difference is caused by 90° polarization switching. However, this kind of switching can be only realized by the exchange of a axis and b axis. By virtue of the reduced orthorhombic distortion, the a-b exchange in SBLT is easier than that in SBT. Unfortunately, stress is created due to the 90° polarization switching in SBLT thin films. The internal stress is found to increase with the repeated switching cycles, and so the polarization reorientation in SBLT is constrained. Thus, the fatigue resistance of SBLT thin films is not thought to be as good as that of SBT. [ABSTRACT FROM AUTHOR]

Abstract: Background: Skin blood flow is believed to link with many diseases, and shows a significant heterogeneity. There are several papers on basal cutaneous microcirculation perfusion in different races, while the data in Chinese is vacant. Objective: The aim was to establish the database of absolute fundamental supply of skin blood flow in the Chinese Han population. Methods: With a full‐field laser perfusion imager (FLPI), the skin blood flow can be quantified. Cutaneous perfusion values were determined in 17 selected skin areas in 406 healthy participants aged between 20 and 80 years (mean 35.05 ± 11.33). Essential parameters such as weight, height were also measured and values of BMI were calculated. The perfusion values were reported in Arbitrary Perfusion Units (APU). Results: The highest cutaneous perfusion value fell on eyelid (931.20 ± 242.59 in male and 967.83 ± 225.49 in female), and pretibial had the lowest value (89.09 ± 30.28 in male and 85.08 ± 33.59 in female). The values were higher in men than women on the bank of fingertips, nose, forehead, cheek, neck and earlobe (P < .05). Perfusion values on stretch and flexion side of forearm had negative correlation with age (P = .01 and P = 4.88 × 10−3, respectively) in male. Abdomen was negatively correlated with BMI in both gender (P = .02, respectively). Conclusions: Skin blood flow values vary with skin regions. There is a tendency to measure higher perfusion values in men than in women. And the values are irrelevant with age or BMI. [ABSTRACT FROM AUTHOR]

Abstract: Objective: The objective of this study was to make noninvasive quantitative analysis of ceramide (CER) in skin of healthy Chinese population by high performance liquid chromatography tandem mass spectrometry. Methods: Seven healthy subjects were selected and the stratified skin samples were available using cyanoacrylate adhesion method. High performance liquid chromatography tandem mass spectrometry, use ceramide Subclass Standard C42H85NO3 Quantification of the 12 corresponding ceramide subclass in the epidermis on the 7 skin samples, which cannot get all the standard of ceramides subclass since the stratum corneum ceramide is complex and diverse. Data were collected and analyzed using full‐flow lipid analysis software (LipidSearch). Results: All the seven skin samples contained 12 subclasses of ceramide and the samples were quantitated with ceramide C42H85NO3 standard. The average contents were 33.63, 27.59, 108.57, 220.75, 149.20, 43.06, and 22.78 μg/mL, respectively. Conclusion: Ceramide is an important lipid in the epidermis and is closely related to the skin barrier function. There are 12 subtypes of ceramide detected in the skin of Chinese healthy people, and there is a difference in the concentration between individuals. The difference may be associated with the skin barrier condition, and may also be related to the unavoidable error in the process of sampling, treatment, and detection. [ABSTRACT FROM AUTHOR]

A two-phase computational fluid dynamics (CFD) simulation for a non-pulsed disc and doughnut solvent extraction column has been developed with commercial CFD software FLUENT. Simulated hydrodynamic results including phase distribution, velocity fields, and holdup are given, which enables predicted holdup to be compared with experimental data. Average absolute relative deviation (AARD) of experimental data and CFD prediction in this study is found to be 10.8%, which is comparable to the estimated error in the experimental data and the predictions from traditional correlations in the literature. To estimate the extent of axial dispersion, a species transport model is used for the continuous phase with a small amount of tracer introduced in the continuous phase, when Sauter mean diameter of the dispersed phase is set to be 3.5 mm. A two-point monitoring method is used to estimate a Peclet number. The tracer concentration distribution in the two-dimensional distance–time space is interpreted with MATLAB along with the experimental measurement. The simulated Peclet numbers are compared with column experiments, and in general the simulation underestimates the experimental data by 60%. Introducing a modified drag law improves the predictions. This work shows that CFD can successfully model the performance of a non-pulsed disc and doughnut solvent extraction column. [ABSTRACT FROM PUBLISHER]

Aluminum borate whiskers (ABOw) with or without ZnAl2O4coating reinforced pure aluminum composites (ABOw/Al, ABOw/ZnAl2O4/Al) were fabricated by squeeze casting. The effects of ZnAl2O4coating on the compressive behaviors, microstructures, and matrix textures of the composites were investigated at different temperatures and strain rates. The results indicate that the maximum compressive flow stress of the composites almost linearly decreases with the increase in temperature. The maximum compressive flow stress of ABOw/ZnAl2O4/Al composite is higher than that of ABOw/Al composite at the same temperature when the strain rate is larger, however, it is reversed when the strain rate is smaller. It is more serious for the fracture of whiskers in ABOw/ZnAl2O4/Al composite than that in ABOw/Al composite at the high compressive strain rate. However, the average length of whiskers in ABOw/ZnAl2O4/Al composite is larger than that in ABOw/Al composite at the low compressive strain rate. The strong matrix texture in ABOw/ZnAl2O4/Al composite appears at the high compressive strain rate, however, it is observed in ABOw/Al composite at the low compressive strain rate. [ABSTRACT FROM PUBLISHER]

Ba1-xAlxTi1-ySiyO3-xNx(BAxTS4N) piezoceramics were prepared by solid-state reaction sintering. The effects of AlN and SiO2co-doping on the phase structure and electrical properties of BaTiO3ceramics were investigated and analyzed. The ceramics adopt a tetragonal crystal symmetry accompanied by the appearance of secondary phases Ba2TiSi2O8and Ba4Ti2O27. The results of temperature dependence of dielectric constant indicate that the Curie temperature of BAxTS4N ceramics is independent of doping content. The BAxTS4N ceramic for the composition ofx= 3% obtains the optimum ferroelectric properties with the remnant polarization (2Pr) of 14.69 μC/cm2and the maximum piezoelectric coefficient (d33) of 230 pC/N. [ABSTRACT FROM AUTHOR]

By pulsed DC magnetron sputtering, boron-doped ZnO (BZO) thin films were deposited on normal glass substrates at different substrate temperatures. The effect of substrate temperature on the properties of the BZO films was systematically investigated. Based on XRD data, the crystallization behaviors and the grain growth kinetics of the BZO films were analyzed. It was found that the substrate temperature of 300 °C is a critical temperature in the grain growth process of the BZO films. That is to say, the grain growth mechanism of the BZO films was different at the substrate temperature range of exceeding 300 °C or not. The morphological, electrical, and optical properties of the BZO films were studied by atomic force microscopy, Hall effect measurement system, and UV-Vis transmission spectroscopy, respectively. With increasing the substrate temperature, the carrier concentration and the carrier mobility increase, and the minimum resistivity (3.4 × 10 Ω cm) is observed at the substrate temperature of 400 °C. Moreover, the transmittance for every film is over 90 % in the visible range, and the optical band edge of the BZO films exhibits blueshift with increasing the substrate temperature. [ABSTRACT FROM AUTHOR]

BaTiO3, BiFeO3 and BiFeO3/BaTiO3 polycrystalline films were prepared by the radio frequency magnetron sputtering on the Pt/Ti/SiO2/Si substrate. The phase structure, converse piezoelectric coefficient and domain structure of BaTiO3, BiFeO3 and BiFeO3/BaTiO3 thin films are characterized by XRD and PFM, respectively. The converse piezoelectric coefficient d33 of BiFeO3/BaTiO3 thin films is 119.5 pm V−1, which is comparable to that of lead-based piezoelectric films. The large piezoelectric response of BiFeO3/BaTiO3 thin films is ascribed to the low-symmetry T-like phase BiFeO3, because the spontaneous polarization vector of T-like phase (with monoclinic symmetry) BiFeO3 can rotate easily under external field. In addition, the reduced leakage current and major domains with upward polarization are also attributed to the large piezoelectricity. [ABSTRACT FROM AUTHOR]

Polymer based composites with high dielectric constant were successfully fabricated using BaTiO3 nanowires with high aspect ratio as inorganic filler and PVDF-HFP as polymer matrix. PVDF-HFP/BaTiO3 nanoparticles composites were also prepared as a contrast. The BaTiO3 nanowires were synthesized via one-step hydrothermal method. The BaTiO3 nanowires and its two types of composites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. For the composites, breakdown strength measurements, tensile tests and broadband dielectric spectroscopy analyses were also carried out. The results show that the two types of fillers are homogeneously dispersed in the matrix. The dielectric constant of composites filled by BaTiO3 nanowires is larger than that filled by BaTiO3 nanoparticles at the same content. Stronger interfacial polarization was found in PVDF-HFP/BaTiO3 nanowire composites. Two theoretical models were employed to predict the dielectric constants of composites, and the experimental data were consistent with the estimated trend. The enhanced dielectric properties of PVDF-HFP/BaTiO3 nanowire composites are attributed to the superior interfacial polarization and high aspect ratio of BaTiO3 nanowires. [ABSTRACT FROM AUTHOR]

Background Hepatitis B reactivation in patients receiving immunosuppressive therapy or chemotherapy may be associated with acute hepatitis, liver failure and/or death. Aim To audit the efficacy of entecavir as compared to lamivudine for the prophylaxis of HBV reactivation in patients with haematological disease receiving immunosuppression or chemotherapy. Methods Patients treated for haematological disease with pretreatment serological evidence of chronic hepatitis B (CHB) (HBV surface antigen, HBsAg positive) or resolved HBV infection (HBsAg negative but HBV core antibody positive) are included in this study. Patients received lamivudine 100 mg or entecavir 0.5 mg daily. Hepatitis B serology, HBV DNA and ALT were audited at baseline, 6 months, year 1, 2 and 3. HBV reactivation was defined as a 1 log increase in HBV DNA from baseline or reversion to sAg positivity. The occurrence of jaundice, symptomatic hepatitis, liver failure or death were audited. Results Of the 40 patients included in the study, 65% (4 CHB and 22 resolved HBV) received entecavir and 35% (11 CHB and 3 resolved HBV) received lamivudine. One patient with resolved HBV experienced HBV seroreversion related to premature cessation of entecavir. Eight patients with CHB (two from entecavir group and six from lamivudine group) had detectable HBVDNA levels at baseline; one case of HBV reactivation related to probable lamivudine resistance was identified. No HBV related deaths occurred. Conclusion Lamivudine and entecavir are both efficacious in the prophylaxis of hepatitis B reactivation. Entecavir should be used in preference to lamivudine in patients CHB with detectable baseline HBV DNA levels. [ABSTRACT FROM AUTHOR]

Cogging torque, as one of the main parasitic demerits of permanent magnet brushless machines, is of particular importance and primary concern during the machine design stage in many high-performance applications. Hence, numerous design techniques have been proposed and employed to effectively alleviate the cogging torque in permanent magnet brushless machines. The effects of rotor step skewing techniques including both conventional and herringbone styles on the cogging torque of permanent magnet brushless machine are comprehensively investigated and compared by synthesized 2-D and 3-D finite-element analysis in this paper. The results have revealed that both the conventional and herringbone rotor step skewing techniques can reduce the cogging torque significantly, but the latter is less effective than the former especially with small skewing step numbers. Moreover, the machine with herringbone rotor step skewing technique has rather peculiar and asymmetric cogging torque profiles, while the machine with conventional rotor step skewing technique exhibits normal and symmetric ones. The validity of the obtained results and findings is underpinned by the experiments on the prototype machine. [ABSTRACT FROM AUTHOR]

nanotubes were fabricated by electroless plating in magnetic field using anodized aluminum oxide template, and the structural and magnetic properties of nanotubes were investigated. It is found that some nano-scale particles form on the wall of nanotubes. Both coercivity ratio and squareness ratio of out-of-plane to in-plane are significantly changed by the applied magnetic field during electroless plating, which indicates that directional ordering in amorphous nanotubes are achieved during electroless plating under magnetic field. The results show that the applied field impacts the magnetic anisotropy of amorphous nanotubes. The anisotropy is stronger with the magnitude of applied field increasing. [ABSTRACT FROM AUTHOR]

A 3 thin film was prepared on the (111) //2/ substrate by the solution coating method. In order to detect the effect of an external magnetic field on the 3 thin film, a fine scan X-ray diffraction with a scan ratio of 0.002°/s was carried out under the magnetic field parallel to the film surface. The result of the in situ analysis of X-ray diffraction for the thin film in the magnetic field indicates that the magnetic field leads to an increase of the integral intensity ratio of compared with that under no magnetic field. The increase of implies a domain switching under the magnetic field, where the domain switching comes from the decreasing residual tensile stress induced by the magnetostriction of 3 in the magnetic field. [ABSTRACT FROM AUTHOR]

A novel method for precise measuring of resistance between ground and auxiliary DC power supply for power systems based on a variable structure measuring circuit is proposed. Three valid working modes of the variable structure measuring circuit can be obtained by two control signals from the central processing unit. The resistances between ground and the negative and positive polarities of the auxiliary DC power supply can be obtained by establishing and solving the equations describing the relationship of circuit parameters in the three working modes. The branch with the ground fault located can be distinguished with one micro-current sensor installed and monitored in each branch. Advantages of this method include simplicity, high precision, low cost, elimination of influence of stray capacitance on the measuring results and no harmful effects of the apparatus on the auxiliary DC power systems. Laboratory and field tests of the apparatus with satisfactory results are carried out and proved the validity and practicability of the method. [ABSTRACT FROM AUTHOR]

The rotor integrity design for a high-speed modular air-cored axial-flux permanent-magnet (AFPM) generator is presented. The main focus is on the mechanical parametric optimization of the rotor, which becomes a more dominating design issue over electromagnetic optimization at high operational speeds. Approximate analytical formulas are employed for preliminary sizing of the mechanical parameters of the rotor, which consists of the permanent magnets, retainment ring, and back iron. Two-dimensional (2-D) finite-element analysis (FEA) models are used to optimize the values of the parameters. Then, 3-D FEA models are developed to verify the final design. Finally, based on the final design, an AFPM prototype is built for experimental validation, and mechanical integrity tests for the rotor are undertaken. The results confirm the validity of the analytical and FEA models, as well as the overall design approach. [ABSTRACT FROM AUTHOR]

The way in which a successful response to ocean pollution is performed is very important, but the marine environment is a very complex system which directly influences the pollution situation. This paper focuses on marine environmental forecast technology. Research on the full forcing oil spill forecast model (FFOSFM) can simulate the movement of oil pollution on the sea surface more accurately than the ordinary method can. An advanced numerical simulation method has been used in this system and some different successful mathematical models (including an atmospheric module, an ocean module, and a wave module) have been coupled together to forecast the full forcing environment factors, such as the sea surface wind, the sea surface current, the wave, and the elevation. This system has also been combined with geographical information system technology and has a user-friendly interface. In this paper, the system has been applied to the Zhoushan Islands as an important part of the Zhoushan Oil Spill Simulation System and supplying the environment data for oil simulation. The real experiment proves that the FFOSFM can forecast the environment data exactly; also, the precision of oil pollution has been greatly updated. Therefore, the FFOSFM can be extended as the basis of a possible future research. [ABSTRACT FROM PUBLISHER]

series of highly (111) oriented Pb(NbZrTi)O (PNZT) thin films of variant thickness were successfully achieved on Pt/Ti/SiO/Si substrate by a sol-gel route. By introducing PbCaLaTiO (PLCT) layer between the PNZT film and Pt electrode, the PNZT film could be crystallized at as low as 500 °C. When a maximum applied voltage is 3 V, it was found that the PNZT film with PLCT seed layer possessed higher remnant polarization (22 μC/cm) as film thickness was scaled down to 50 nm. It was also found that enhanced pyroelectric properties could be observed in 50-nm thickness PNZT thin film due to its relatively low dielectric constant. The results demonstrated that the film thickness could be scaled down for low voltage operations using lattice matched interface between PNZT film and PLCT seed layer on Pt/Ti/SiO/Si substrate, and this interface optimization is the key technology for synthesizing thin PNZT films at low temperature with good insulating and electric properties. [ABSTRACT FROM AUTHOR]

FeAg and FeAg/Pt films were prepared by dc magnetron sputtering at room temperature. The effects of Ag volume fraction in FeAg films and postannealing temperature and time on structure and magnetic properties of FeAg and FeAg/Pt films have been investigated. The results show that the as-deposited FeAg films are metastable. After annealing at 300°C, the phase separation of metastable FeAg films happened and the highest coercivity is obtained in FeAg/Pt film. With increasing annealing temperature, the ordering and the magnetic properties of the FeAg/Pt films were improved. When the FeAg/Pt films are annealed at 600°C for different annealing times, a long annealing time enhances the ordering of the metastable FeAg/Pt films and affects the orientation development. When the films are annealed for a long time, the grain size and the magnetic domain size also increase, which lead to an increase of correlation length due to the growth of FePt grains. [ABSTRACT FROM AUTHOR]

Focusing on the relative location of the centre of gravity of the pulse-width modulation waveform in each section, a novel direct digital sine pulse-width modulation (SPWM) method based on equal-area theorem for multilevel inverters is proposed in this paper. Three different direct digital SPWM schemes are illustrated and investigated thoroughly in terms of total harmonic distortion (THD) and amplitude of the fundamental-frequency voltage, and the best scheme with the lowest THD is identified. The THD and fundamental voltage produced with the proposed method with modulation index M varying from zero to its maximum value are calculated and compared with level-shifted carrier-based SPWM method. It is demonstrated that the proposed direct digital SPWM method can provide far lower THD, while its fundamental voltages are on par with the carrier-based SPWM method. Other advantages of the proposed modulation scheme include simplicity, digital oriented and generalised for multilevel inverter with any levels and any topologies, including cascaded H-bridge, neutral point clamped, flying-capacitor and any other types of inverters. Simulations and experiments are carried out. The experimental results agree well with simulations, which prove the validity of the proposed digital SPWM method. [ABSTRACT FROM AUTHOR]

This study investigates in detail the properties of multiple solutions of different existing selective harmonic elimination (SHE)-pulse-width modulation (PWM) schemes for multilevel voltage source inverters. In order to obtain more solutions to SHE-PWM problems, a novel half-wave symmetry SHE modulation method and its generalised formulation are proposed. The advantages of the proposed formulation include simplicity in format, flexibility in PWM waveforms and a broad solution space. Taking a five-level inverter with 20 points in half a cycle as an example, 12 groups of solutions at modulation index (M) of 0.8 are obtained and illustrated. A set of solutions for M varying from 0 to 1.15 are also listed in forms of initial values and their effective regions. Simulations on a Psim platform are carried out. An experimental prototype with a five-level cascade voltage source inverter topology is built and investigated. The experimental results agree well with simulated ones, which prove the validity and practicability of the new method. [ABSTRACT FROM AUTHOR]

The authors consider the link of parallel profiles with linear dependencies (PARALIND) model with multiple-input multiple-output orthogonal frequency division multiplexing receiver. The authors derive a PARALIND-based blind receiver algorithm that has much close performance to non-blind minimum mean-squared error and it has better performance than constant modulus method. Neither the channel state information nor statistical characteristic is a necessity for the presented PARALIND algorithm, whereas the proposed algorithm distinctively supports small sample sizes. Numerical results verify its useful behaviour. [ABSTRACT FROM AUTHOR]

Pure aluminium matrix composites reinforced by ZnAl2O4 coated Al18B4O33 whiskers were fabricated by squeeze casting. The effect of ZnAl2O4 coating on the Young's modulus of the composite was investigated. The results show that the Young's modulus of the composite significantly increases with increasing ZnAl2O4 coating content. The influence mechanisms of ZnAl2O4 coating on the Young's modulus of the composite were analysed. The increase in load transfer area of whisker/matrix interface and the volume fraction of effective reinforcement with increasing ZnAl2O4 coating content can increase the Young's modulus of the composites. The steps can provide an additional load transfer from the matrix to whiskers during the tensile deformation of the composites. [ABSTRACT FROM AUTHOR]

Cu matrix composites with different volume fraction of Ag coated β-eucryptite particulates were successfully fabricated by powder metallurgy method. Low thermal expansion coefficient and high thermal conductivity were attained simultaneously in the new Cu matrix composite. The microstructure of β-eucryptite-Cu composite was studied by scanning electron microscope and transmission electron microscope. The thermophysical properties of β-eucryptite-Cu composites were analysed by means of thermal dilatometer and diathermometer. No interfacial reaction products between β-eucryptite and Cu were found in the composite. The research indicates that β-eucryptite, which has a negative coefficient of thermal expansion, is a useful reinforcement, which can remarkably reduce the coefficient of thermal expansion of Cu matrix composite. The effects of volume fraction of β-eucryptite particulates on the thermal expansion coefficient and thermal conductivity of the composite were investigated. [ABSTRACT FROM AUTHOR]

A high-speed coreless surface mounted axial flux permanent magnet generator with circular magnets and coils is proposed and studied. The performances of the machine are estimated and optimised by approximate theoretical analysis and comprehensive three-dimensional (3D) electromagnetic finite element analysis (FEA). Mechanical stresses in the rotor disc developed at high rotational speed are analysed and evaluated by 3D mechanical FEA to ensure the rotor's integrity. Finally, a prototype machine is constructed and tested. Both the experimental and predicted results have shown that the proposed generator possesses distinct advantages such as simple structure and high efficiency. The prototype also demonstrates its utility as a very low-cost generator. [ABSTRACT FROM AUTHOR]

Permanent-magnet flux-switching (PMFS) machine offers high torque density, impressive flux-weakening capability and mechanical ruggedness because of its distinctive configuration, and is potentially suitable for the application in automotive integrated-starter-generators (ISGs). However, the PMFS machine generally exhibits higher cogging torque compared with other machines commonly used in ISGs. Minimisation of the cogging torque in the PMFS machine for its utility in ISGs is therefore of particular importance. Four rotor topologies are proposed here as cost-effective means to suppress the cogging torque of a PMFS ISG. The validity of the proposed techniques has been confirmed by both two-dimensional finite-element analysis and experimental results. Moreover, the influence on the back electromagnetic force by these techniques is also investigated. [ABSTRACT FROM AUTHOR]

Cogging torque in permanent magnet flux-switching machines (PMFSM) is relatively high compared with other types of PM motors, because of their unique doubly salient structure. In this study, a new rotor teeth axial pairing (RTAP) technique is proposed. As verified with both 2-D and 3-D finite element analysis, as well as laboratory tests, the RTAP technique can effectively reduce the cogging torque, while its implementation is more flexible than the conventional rotor teeth circumferential pairing (RTCP) technique. Furthermore, the RTAP technique is also applicable to other types of machine with a salient iron rotor. [ABSTRACT FROM AUTHOR]

In direct-drive electric propulsion systems, where there is no reduction gear to minimize and absorb the adverse effects of cogging torque generated by the permanent-magnet (PM) machine, minimization of cogging torque generation is of particular importance. In this paper, a novel axial pole-pairing method is proposed to minimize cogging torque generation in a special three-phase outer-rotor PM brushless machine, which uses uneven stator poles to enhance back electromotive force (EMF). Analytical formulas of the machine's cogging torque are first derived. The new technique is compared with conventional cogging torque suppression methods by means of analytical models and comprehensive finite-element analysis (FEA). The FEA results show that the new method not only achieves effective cogging torque reduction, but also results in improved harmonic content of the back EMF. The validity of the FEA model is verified by experimental results from the prototype machines. Finally, the significance of optimizing both the load-independent machine design techniques and load-dependent driving techniques to achieve overall torque ripple minimization is discussed. [ABSTRACT FROM AUTHOR]

Highly (100)-oriented Pb0.8La0.1Ca0.1Ti0.975O3 (PLCT) thin films deposited on Pt/Ti/SiO2/Si substrate were successfully achieved by a sol–gel route. The influence of annealing temperature on microstructures and electric properties was investigated; it was found that the PLCT film could be crystallized only at 450 °C. When the annealing temperature increased to 500 °C, the PLCT film exhibited highly (100)-oriented, which also possessed higher remnant polarization Pr (27 μC/cm2) and better pyroelectric figure of merit ( Fd = 205 μC/m2k) at room temperature. It was also found too high annealing temperature (625 °C) could lead to recrystallization of film, and the small grains caused by recrystallization could make polarization reversal difficult and disturbed the preferred crystal growth in film, which was not benefit to obtain enhanced electric properties. [ABSTRACT FROM AUTHOR]

Co-doped ZnO films were successfully fabricated on Si substrates by sol–gel process. The effects of Co concentration and preheating temperature on the structure and magnetic properties of the Zn1− xCo xO films were systematically studied. The results revealed that the films were highly c-axis oriented and contained no impurity phase. With preheating temperature increasing, the orientation degree of the films decreased. When the Co concentration and oxygen vacancy of the films are almost changeless, the enhancement of ferromagnetism in films originates from the orientation degree of the films increasing. [ABSTRACT FROM AUTHOR]

The magnetic and structural properties of atomic-scale [Fe/Pt]18 and [Fe/Pt/Ag]18 multilayer films annealed at 350 and 400°C have been investigated. The results indicate that, by introducing thin Ag addition layers, the ordering temperature of FePt with nominal 7.4-nm thickness (excluding Ag thickness) can be significantly reduced to 350°C, at which a relatively large coercivity is achieved. When annealing temperature increases to 400°C, the atomic-scale [Fe/Pt]18 and [Fe/Pt/Ag]18 multilayer films show (001) orientation. The reduced diffusion length of atoms in atomic-scale multilayer films and an enhanced atomic diffusion coefficient produced by Ag doping led to the low-temperature ordering and (001) orientation of L10 FePt phase. [ABSTRACT FROM AUTHOR]

This study presents a mean shift clustering-based moving object segmentation approach in the H.264 compressed domain. The motion information extracted from H.264 compressed video, including motion vectors (MVs) and partitioned block size, are used as segmentation cues. The MVs are processed by normalisation, weighted 3D median filter and motion compensation to obtain a reliable and salient MV field. The partitioned block size is used as a measure of motion texture in the process of the MV field. Based on the processed MV field, the authors employ the mean shift-based mode seeking in spatial, temporal and range domain to develop a new approach for compact representation of the MV field. Then, the MV field is segmented into different motion-homogenous regions by clustering the modes with small spatial and range distance, and each object is represented by some dominant modes. Experimental results for several H.264 compressed video sequences demonstrate good performance and efficiency of the proposed segmentation approach. [ABSTRACT FROM AUTHOR]

Small industrial three-phase induction motors (IMs) normally suffer from poor operational efficiency and power factor. This paper presents a high-performance line-start permanent magnet synchronous motor (LSPMSM) which is developed by simple modifications of an off-the-shelf small industrial three-phase IM with minimized additional costs. Two-dimensional (2-D) dynamic finite element analysis (FEA) models are employed to assess the machine performances, which are validated by comprehensive experimental results. The experimental comparisons between the amended LSPMSM and the original IM have indicated that significant improvements in efficiency and power factor can be achieved by the proposed LSPMSM. [ABSTRACT FROM AUTHOR]

An improved model for the back-electromagnetic-force (back-EMF) and cogging torque characteristics of a novel axial flux permanent magnet (AFPM) synchronous machine with a segmental laminated stator is presented. Based on a 3-D finite-element analysis (FEA) modeling approach that takes into the anisotropic properties of the machine's laminated cores, the proposed model provides superior performance prediction to existing isotropic models, in which lamination effects are not considered. An anisotropic model has been developed to predict the back-EMF and cogging torque of an existing prototype AFPM machine with optimized rotor magnets. Experimental results of the AFPM machine are compared against the results from the FEA models based on anisotropic and isotropic modeling, respectively. The results show that anisotropic modeling provides more accurate performance prediction of the AFPM machine with laminated cores. [ABSTRACT FROM AUTHOR]

High-torque and low-speed electrical drives are often employed for applications where mechanical gearing cannot be accommodated. On the other hand, permanent-magnet (PM) gear has drawn significant attention from both academies and industries due to the conspicuous merits, such as reduced acoustic noise, maintenance free, improved reliability, precise peak torque transmission capability, and inherent overload protection. In this paper, a magnetic-geared PM brushless motor is presented. It is a novel low-speed and high-torque motor which merges the advantages of conventional PM brushless motor and PM gear. Its topology and operation principle are introduced. Some techniques are employed to optimize and improve the motor performance, while the validity of the proposed techniques is verified with finite-element analysis. Moreover, an alternative operation condition, which can further reduce the motor speed and increase its output torque, is proposed and analyzed. [ABSTRACT FROM AUTHOR]

On the basis of ω-scan x-ray diffraction (XRD), quantitative and qualitative characterization methods for fiber texture are proposed. The physical meaning of ω-scan curve is discussed in detail, and it is shown that the relative intensity curve of ω-scan XRD for a certain crystal plane is proportional to the pole density of the plane. Then qualitative and quantitative characterization methods for fiber texture are proposed from the concept of pole density. The proposed methods can be used in any crystal system. As an example for experimental verification, an orientation distribution function (ODF) experiment and a series of ω-scan XRD experiments are performed on a sputtered platinum film. From the comparison between the result of the ODF experiment and that of the analyses on the ω-scan XRD experiments, it is proved that the proposed qualitative and quantitative methods are effective and simple. [ABSTRACT FROM AUTHOR]

The pure aluminium composites reinforced by ZnO coated aluminium borate whiskers were fabricated by squeeze casting. The microstructure of the composite was observed using an optical microscope and the thermal expansion behaviours of the composites were investigated in the range from 50 to 400°C. In addition, the effects of heat treatment and thermal cycling on the thermal expansion behaviours of the composite were also investigated. The results show that the coefficient of thermal expansion of as cast composites decreases with the ZnO coating content increasing. However, heat treatment time and thermal cycling lead to an increase in the CTE of the composite. [ABSTRACT FROM AUTHOR]