This study examines the pursuit-evasion game involving unmanned aerial vehicles (UAVs), with a specific focus on the scenario of N-pursuers-one-escapee. The primary objective is to develop an optimal strategy for the escapee when the pursuers possess superior capabilities. To obtain this objective, we conduct the following study. Firstly, to enhance realism, a non-cooperative differential game model is formulated, incorporating multiple motion characteristics, including aerodynamics, overloading, and imposed constraints. Secondly, the end-value performance index is subsequently converted to an integral one, simplifying the solution process of the Hamilton-Jacobi-Bellman (HJB) equation. An iterative method is utilised to determine the covariates using the Cauchy initial value problem, and its convergence and uniqueness are established. The optimal avoidance strategy is subsequently derived from the covariates. Finally, the superiority of the proposed strategy is validated through simulation experiments and compared to three advanced optimal avoidance strategies. A total of 1,000 anti-jamming simulation experiments are conducted to verify the robustness of the proposed strategy.

The polycrystalline Nd3+-doped rare earth orthotantalate LuTaO4 was synthesized with high temperature solid-state reaction method, and the structure was determined by applying the Rietveld refinement to its x-ray diffraction. Also, the emission and excitation spectra at 7.6 K have been analyzed. The free-ions and crystal-field parameters were fitted to the experimental energy levels with the root mean square deviation of 14.6 cm−1. According to the crystal-field calculations, 152 Stark energy levels of Nd3+ were assigned. Finally, the fitting results of free-ions and crystal-field parameters were compared with those already reported for Nd3+:YAlO3. The results indicate that the free-ions parameters are similar to those of the Nd3+ in LuTaO4 and YAlO3 hosts except for the values of two-body electrostatic parameter γ, and the 2-rank crystal-field parameters of two hosts have relatively large differences while other crystal-field parameters have been similar to each other. Moreover, the crystal-field interaction of Nd3+ in LuTaO4 is stronger than that in YAlO3.

Canine hookworm infections are endemic worldwide, with zoonotic transmission representing a potentially significant public health concern. This study aimed to investigate hookworm infection and identify the prevalent species from stray and shelter dogs in Guangzhou city, southern China by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) based on internal transcribed spacer (ITS) sequences. From March 2011 to July 2012, fresh faecal samples from a total of 254 dogs were obtained from five locations, namely Conghua, Baiyun, Liwan, Haizhu and Panyu, in Guangzhou. These samples were screened for the presence of hookworm eggs using light microscopy, with an overall prevalence of 29.53% being recorded. The highest prevalence of 45.28% was found in suburban dogs from Conghua compared with lower values recorded in urban dogs in Haizhu (21.43%), Baiyun (18.97%), Panyu (18.18%) and Liwan (15%). The prevalence in stray dogs was significantly higher than that in shelter dogs. PCR-RFLP analysis showed that 57.33% were detected as single hookworm infections with Ancyclostoma caninum, and 22.67% as A. ceylanicum, while 20% were mixed infections. This suggests that high prevalences of both hookworm species in stray and shelter dogs in China pose a potential risk of transmission from pet dogs to humans.

The effects of laser incidence angle on lateral fast electron transport at front target surface, when a plasma is preformed, irradiated by intense (>1018 W/cm2) laser pulses, are studied by Kα imaging technique and electron spectrometer. A horizontally asymmetric Kα halo, resulting from directional lateral electron transport and energy deposition, is observed for a large incidence angle (70°). Moreover, a group of MeV high energy electrons is emitted along target surface. It is believed that the deformed preplasma and the asymmetrical distribution of self-generated magnetic field, at large incidence angle, play an important role in the directional lateral electron transport.

Measurements are presented of the magnetoelectric (ME) coupling of nontoxic lead-free multiferroic composites 0.4CoFe2O4-0.6[0.948(K0.5Na0.5)NbO3-0.052LiSbO3]. The composites are found to exhibit an interesting dielectric response under a dc magnetic bias field. The positive magnetodielectric behavior and its strong frequency dependence in the composite could be related to magnetoresistance and the Maxwell-Wagner effect. The ME effects are strongly dependent on the driving field frequency and dc magnetic bias field. The frequency and magnetic field dependence of direct and converse ME coefficients are related to the relative dielectric constant and the variation in the piezomagnetic coupling with magnetic field, respectively. In addition, the dependence of direct and converse ME coefficients on frequency and magnetic field is quite similar in this multiferroic particulate composite.

High-pressure in situ angular dispersive x-ray diffraction study on the wurtzite-type InN nanowires has been carried out by means of the image-plate technique and diamond-anvil cell (DAC) up to about 31.8 GPa. The pressure-induced structural transition from the wurtzite to a rocksalt-type phase occurs at about 14.6 GPa, which is slightly higher than the transition pressure of InN bulk materials (∼12.1 GPa). The relative volume reduction at the transition point is close to 17.88%, and the bulk modulus B0 is determined through fitting the relative volume-pressure experimental data related to the wurtzite and rocksalt phases to the Birch–Murnaghan equation of states. Moreover, high-pressure Raman scattering for InN nanowires were also investigated in DAC at room temperature. The corresponding structural transition was confirmed by assignment of phonon modes. We calculated the mode Grüneisen parameters for the wurtzite and rocksalt phases of InN nanowires.

Recombining plasmas produced by picosecond laser pulses are characterized by measuring ratio of intensities of resonance lines of H- and He-like ions in the plasmas. It is found that the rapidly recombining plasmas produced by picosecond laser pulses are suitable for highgain operation.

Part I of this paper was concerned with kinematic workspaces of walking machines, while this paper addresses the static workspaces of a walking machine and their graphical representation. The results of static analysis are presented; the static workspace constraints are established; an algorithm for investigation of static workspaces is presented; and the position static workspaces are analysed and graphically represented for an example walking machine design.

N-polar and Ga-polar GaN grown on c-plane sapphire by a metal-organic chemical vapor deposition (MOCVD) system were used to fabricate platinum deposited Schottky contacts for hydrogen sensing at room temperature. Wurtzite GaN is a polar material. Along the c-axis, there are N-face (N-polar) or Ga-face (Ga-polar) orientations on the GaN surface. The Ohmic contacts were formed by lift-off of e-beam deposited Ti (200 Å)/Al (1000 Å)/Ni (400 Å)/Au (1200 Å). The contacts were annealed at 850°C for 45 s under a flowing N2 ambient. Isolation was achieved with 2000 Å plasma enhanced chemical vapor deposited SiNx formed at 300°C. A 100 Å of Pt was deposited by e-beam evaporation to form Schottky contacts. After exposure to hydrogen, Ga-polar GaN Schottky showed 10% of current change, while the N-polar GaN Schottky contacts became fully Ohmic. The N-polar GaN Schottky diodes showed stronger and faster response to 4% hydrogen than that of Ga-polar GaN Schottky diodes. The abrupt current increase from N-polar GaN Schottky exposure to hydrogen was attributed to the high reactivity of the N-face surface termination. The surface termination dominates the sensitivity and response time of the hydrogen sensors made of GaN Schottky diodes. Current-voltage characteristics and the real-time detection of the sensor for hydrogen were investigated. These results demonstrate that the surface termination is crucial in the performance of hydrogen sensors made of GaN Schottky diodes.

Different bulk metallic glasses (BMGs) were prepared in ductile Cu47.5Zr47.5Al5, Zr62Cu15.4Ni12.6Al10, and brittle Zr55Ni5Al10Cu30 alloys by controlling solidification conditions. The achieved microstructures were characterized by x-ray diffraction, differential scanning calorimetry, transmission electron microscopy, and synchrotron- based high-energy x-ray diffraction. Monolithic BMGs obtained by high-temperature injection casting are brittle, while BMGs bearing some nanocrystals with the size of 3 to 7 nm and 2 to 4 nm, obtained by low-temperature injection casting and in situ suction casting, respectively, exhibit good plasticity. It indicates that the microstructures of BMGs are closely affected by the solidification conditions. Controlling the solidification conditions could improve the plasticity of BMGs.

Damage behavior of Cu–Ta bilayered films bonded to polyimide (PI) substrates has been investigated by cyclic loading tests. Experimental results show that fatigue cracks preferentially initiated in the Ta layer close to the Ta–PI interface and propagated into the Cu layer perpendicular to the interface. The alignment of nanometer-sized Cu grains resulted from the potential GB sliding combined with a small amount of grain rotation was found in the damage zone ahead of the crack tip, and that is suggested to be a likely damage mechanism to accommodate cyclic plastic strain ahead of the fatigue crack tip of the submicrometer-thick Cu layer.

Bulk glass formation of the Co–Cr–Mo–C–B–Er alloy system was investigated in this paper. The Co50Cr15Mo14C15B6 (at.%) alloy could be cast into fully glassy rod with a diameter up to 2 mm. By adding 2 at.% Er to this alloy, the critical diameter for glass formation reached 10 mm. The excellent glass formability of the Er-doped alloy was mainly attributed to its relatively large reduced glass transition temperature of 0.61, near-eutectic composition, and the necessity of redistribution of the Er atoms for precipitation of crystalline Co6Mo6C phase in the undercooled liquid on cooling.

Radio observational results at 232 MHz and multifrequency studies of supernova remnant (SNR) HB21 are presented in this paper. Both the integrated spectral index and the spatial variations of spectral index of the remnant were calculated by combining the new map at 232 MHz with previously published maps made at 408, 1420, 2695, and 4750 MHz.

We present results of a comprehensive set of first-principles total-energy calculations of native and impurity-defect complexes in ZnO and use these results to elucidate the problems that occur in efforts to achieve p-type doping. The analysis naturally leads to new approaches that are likely to overcome the difficulties. The results provide detailed explanations of recent puzzling observations made in attempts to produce p-type ZnO.

A kinetic model is presented to simulate the strain relaxation in the GexSi1−x/Si(100) systems. In the model, the nucleation, propagation and annihilation of threading dislocations, the interaction between threading dislocations and misfit dislocations, and surface roughness are taken into account. The model reproduces a wide range of experimental results. The implications of its predictions on the threading dislocation reduction during the growth processes of the heteoepitaxial thin film systems are discussed.

Mesa and planar geometry GaN Schottky rectifiers were fabricated on 3-12µm thick epitaxial layers. In planar diodes utilizing resistive GaN, a reverse breakdown voltage of 3.1 kV was achieved in structures containing p-guard rings and employing extension of the Schottky contact edge over an oxide layer. In devices without edge termination, the reverse breakdown voltage was 2.3 kV. Mesa diodes fabricated on conducting GaN had breakdown voltages in the range 200-400 V, with on-state resistances as low as 6m Ω·cm−2.

The near-surface (400-500Å) of p-GaN exposed to high density plasmas is found to become more compensated through the introduction of shallow donors. At high ion fluxes or ion energies there can be type-conversion of this surface region. Two different methods for removal of the damaged surface were investigated; wet etching in KOH, which produced self-limiting etch depths or thermal annealing under N2 which largely restored the initial electrical properties.

We report on the dc performance of the first GaN pnp bipolar junction transistor. The structure was grown by MOCVD on c-plane sapphire substrates and mesas formed by low damage Inductively Coupled Plasma etching with a Cl2/Ar chemistry. The dc characteristics were measured up to VBC of 65 V in the common base mode and at temperatures up to 250°C. Under all conditions, IC ∼ IE indicated higher emitter injection efficiency. The offset voltage was ≤ 2 V and the devices were operated up to power densities of 13.9 kW·cm−2.

Recent advances in developing process modules for GaN power devices are reviewed. These processes include damage removal in dry etched n- and p-GaN, implant doping and isolation, novel gate dielectrics, improved Schottky and ohmic contacts and deep via etching of SiC for hybrid GaN/SiC structures.