[en] To study runaway transient of pumped storage power station caused by pumping power failure, three dimensional unsteady numerical simulations were executed on geometrical model of the whole flow system. Through numerical calculation, the changeable flow configuration and variation law of some parameters such as unit rotate speed,flow rate and static pressure of measurement points were obtained and compared with experimental data. Numerical results show that runaway speed agrees well with experimental date and its error was 3.7%. The unit undergoes pump condition, brake condition, turbine condition and runaway condition with flow characteristic changing violently. In runaway condition, static pressure in passage pulses very strongly which frequency is related to runaway speed

[en] The design of high-altitude and long-endurance solar aircraft is obviously different from that of conventional aircraft. Its unique energy system and operating conditions make it necessary to carefully weigh the key technical details in design. The structure has a great influence on the endurance performance of solar aircraft. The structure weight can be roughly estimated by the proportion of the airborne energy system to the total weight of the aircraft, so as to optimize the structure. Through the analysis of several typical solar aircraft, it can be concluded that the aerodynamic layout and structure design have a great impact on the flight time and performance of solar aircraft. Finally, the challenges faced by solar aircraft are presented, which can provide reference for the design of solar aircraft in the future and help. (paper)

[en] At the present time, the ultrasonic Doppler measuring means has been extensively used in the human body's bloodstream speed measuring. The ultrasonic Doppler measuring means can achieve the measuring of liquid flux by detecting Doppler frequency shift of ultrasonic in the process of liquid spread. However, the detected sound wave is a weak signal that is flooded in the strong noise signal. The traditional measuring method depends on signal-to-noise ratio. Under the very low signal-to-noise ratio or the strong noise signal background, the signal frequency is not measured. This article studied on chaotic movement of Duffing oscillator and intermittent chaotic characteristic on chaotic oscillator of Duffing equation. In the light of the range of the bloodstream speed of human body and the principle of Doppler shift, the paper determines the frequency shift range. An oscillator array including many oscillators is designed according to it. The reflected ultrasonic frequency information can be ascertained accurately by the intermittent chaos quality of the oscillator. The signal-to-noise ratio of -26.5 dB is obtained by the result of the experiment. Compared with the tradition the frequency method compare, the dependence to signal-to-noise ratio is lowered consumedly. The measuring precision of the bloodstream speed is heightened

[en] The gears is a main driving device in the modern rotational machine equipments at the present time. In this paper, the Mallat algorithm of wavelet and wavelet packet is studied and is used in the fault diagnosis of the rotational machine equipment. The complicated mechanical vibration signals are analyzed by it. The weak signal is extracted effectively and the signal of the fault symptom is located in the time domain. The testing results proved the value of the analytic method

[en] A cascaded target normal sheath acceleration (TNSA) scheme is proposed to simultaneously increase energy and improve energy spread of a laser-produced mono-energetic proton beam. An optimum condition that uses the maximum sheath field to accelerate the center of the proton beam is theoretically found and verified by two-dimensional particle-in-cell simulations. An initial 10 MeV proton beam is accelerated to 21 MeV with energy spread decreased from 5% to 2% under the optimum condition during the process of the cascaded TNSA. The scheme opens a way to scale proton energy lineally with laser energy

[en] The structural layers and methods of multi-sensor information fusion technology are analysed, and its application in fault diagnosis of hydraulic system is discussed. Aiming at hydraulic system, a model of hydraulic fault diagnosis system based on multi-sensor information fusion technology is presented. Choosing and implementing the method of information fusion reasonably, the model can fuse and calculate various fault characteristic parameters in hydraulic system effectively and provide more valuable result for fault diagnosis of hydraulic system.

[en] A new spin-dependent deflection mechanism is revealed by considering the spin-correlated radiation-reaction force during laser-electron collision. We found that such deflection originates from the non-zero work done by the radiation-reaction force along the laser polarization direction in each half-period, which is larger/smaller for spin-anti-paralleled/spin-paralleled electrons. The resulted anti-symmetric deflection is further accumulated when the spin-projection onto the laser magnetic field is reversed in adjacent half-periods. The discovered mechanism dominates over the Stern–Gerlach deflection for electrons of several hundreds of MeV and 10 PW-level laser peak power. The results provide a new perspective to study the strong-field QED physics in quantum radiation-reaction regime and an approach to leverage the study of radiation-dominated and strong-field QED physics via particle spins. (paper)

[en] A new scheme for proton acceleration by cascaded collisionless electrostatic shock (CES) is proposed. By irradiating a foil target with a moderate high-intensity laser beam, a stable CES field can be induced, which is employed as the accelerating field for the booster stage of proton acceleration. The mechanism is studied through simulations and theoretical analysis, showing that a 55 MeV seed proton beam can be further accelerated to 265 MeV while keeping a good energy spread. This scheme offers a feasible approach to produce proton beams with energy of hundreds of MeV by existing available high-intensity laser facilities

[en] We report room temperature ferromagnetism enhancement of Cu-doped ZnOS (Zn_1-xCu_xO_1-yS_y) alloy thin films with high hole concentration. The Zn_0.91Cu_0.09O_0.92S_0.08 alloy thin films with a hole concentration of 4.3 × 10¹⁹ cm^-3 show the strongest magnetization of 1.5μ_B/Cu. First-principles calculation shows that high hole concentration stabilizes the ferromagnetic ordering in the Zn_1-xCu_xO_1-yS_y system, indicating a strong correlation between ferromagnetic stability and hole concentration. These results suggest that the Zn_1-xCu_xO_1-yS_y alloy with high hole concentration is promising to find applications in spintronic devices. (paper)

[en] Two-dimensional tailoring of a proton beam is realized by a “particle lens” in our experiment. A large quantity of electrons, generated by an intense femtosecond laser irradiating a polymer target, produces an electric field strong enough to change the trajectory and distribution of energetic protons flying through the electron area. The experiment shows that a strip pattern of the proton beam appears when hot electrons initially converge inside the plastic plate. Then the shape of the proton beam changes to a “fountain-like” pattern when these hot electrons diffuse after propagating a distance.