[en] The operation principle of integral construction of Tesla transformer and PFL was investigated in Tesla-transformer-type accelerator. Experiment was carried out on Tesla transformer's secondary winding to study the impulse voltage distribution while PFL was discharging. The regularities of turn-ground voltage distribution and interturn voltage distribution were summarized. Voltage distribution within PFL was calculated and it was compared with the experimental result. Structural winding of parallel coils in the head, parallel coils in the end and shading ring were used to improve voltage distribution and that was testified by experiment. The results indicate that taper winding doesn't effect electric field within PFL, the turn-ground voltage appears linearly, the interturn voltage fluctuates seriously and it is the biggest in head of winding. The three optimized methods help to depress oscillation, the structural winding of parallel coils in the head decreases the interturn voltage in head of winding remark-ably and the parallel coils in the end decrease the interturn voltage in the end. (authors)

[en] In order to study the impulse voltage distribution in the pulse transformer's taper windings, experiment was carried out with 3 kinds of single impulse voltage input whose pulse width was 1 μs, 500 ns and 100 ns respectively. Under experimental conditions, turn-to-ground voltage and interturn voltage in the structural windings with air-core and iron-core were compared. The result indicates that the impulse voltage distribution in the coils is nonlinear and oscillates obvious at high frequency, which increases voltage gradients in the head of windings obviously. Distortion also appears as the pulse width decreases. The interturn voltage fluctuates due to the voltage wave transmission. The extrema interturn voltage always appear in either head or end of the windings. To some extent, the iron-core helps to depress the oscillation but increase the interturn voltage. (authors)

[en] Based on a combination of pulse transformer and distributed electrical parameter pulse forming line(PFL), a high power pulse generating and forming technology is introduced. The basic plan theory and method is briefly summarized, and an integrative generator of pulse transformer and PFL is developed. With the coaxial open cores of the transformer acting as the inner and outer conductors of PFL, this device unifies two important individual parts and has a compact configuration. The high-voltage generator can steadily obtain output pulse voltage of 760 kV, peak power of 23 GW and more than 40 ns pulse duration when the transformer keeps a voltage of 1.65 MV at a burst of 100 Hz. (authors)

[en] The theory and characteristic of a compact Tesla transformer are introduced, and an unitized configuration design is performed for 1.0 MV, 100 Hz Tesla transformer and 40 Ω, 40 ns pulse forming line (PFL). Two coaxial open cores in Tesla transformer serve as the inner and outer conductors of PFL, and a traditional PFL is combined with the Tesla transformer, then the pulse generator can be smaller, more efficient, and more stable. The designed compact Tesla transformer employed in electron beams accelerator CHP01 can charge PFL of 600 pF for 1.3 MV voltage at a single shot, and keep 1.15 MV at 100 Hz repeated rates. Furthermore, a continuance run in 5 seconds is achieved by Tesla transformer under voltage and frequency ratings. (authors)

[en] A modulator type pulse generator which is based on Blumlein Pulse Forming Net and pulsed transformer, constructed by authors is described. This generator can deliver pulse of 300 kV to a load, and it has an output impedance of 100 Ω and a pulse width of 500 ns. It can operate steadily at pulse repetition rates as high as 100 Hz. Three kinds of cathodes are studies on this pulse generator, and the diode can deliver electron-beam pulse of nearly 300 kV, pulse width 500 ns and repetition frequency 50 Hz

[en] Effects of various finish rolling temperatures on the microstructure, texture, mechanical properties and stretch formability of rolled and annealed Mg-3Al-0.5Ca-0.2Gd (wt%) alloy were investigated in this paper, and it was found that compared with grain size and second phase particles, the basal textures, tensile properties and stretch formability Mg-3Al-0.5Ca-0.2Gd alloy are more sensitive to the increasing finishing rolling temperature. For the rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy, their grains barely grow up and second phase particles are slightly coarsened, while their basal poles are obviously weakened and tilted with increasing finish rolling temperature. Consequently, the weakened and RD-tilted basal textures are beneficial to the gradually improved elongation and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy. It is investigated that the gradually activated non-basal slips, e. g. 〈c 〉, 〈c + a〉 dislocations due to the increasing finish rolling temperature could contribute to the weakened RD-tilted textures in rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy. (paper)

[en] With the polarization of quantum-dot cell and quantum phase serving as state variables, this paper does both theoretical analysis and simulation for the complex nonlinear dynamical behaviour of a three-cell-coupled Quantum Cellular Neural Network (QCNN), including equilibrium points, bifurcation and chaotic behaviour. Different phenomena, such as quasi-periodic, chaotic and hyper-chaotic states as well as bifurcations are revealed. The system's bifurcation and chaotic behaviour under the influence of the different coupling parameters are analysed. And it finds that the unbalanced cells coupled QCNN is easy to cause chaotic oscillation and the system response enters into chaotic state from quasi-periodic state by quasi-period bifurcation; however, the balanced cells coupled QCNN also can be chaotic when coupling parameters is in some region. Additionally, both the unbalanced and balanced cells coupled QCNNs can possess hyper-chaotic behaviour. It provides valuable information about QCNNs for future application in high-parallel signal processing and novel ultra-small chaotic generators. (general)

[en] As the application field of magnesium alloys broadens, it is essential to develop magnesium alloys with combination of high strength and high formability. A newly designed TRC-ZAEX2100 alloy sheets were fabricated via twin-roll casting (TRC) and subsequent hot rolling, and the corresponding variations of microstructure, texture, mechanical property and stretch formability were investigated. The results showed that TRC-ZAEX2100 alloy sheets with high strength and high formability were produced and the related yield strength along RD reaches 201.2 MPa together with excellent IE values of 6.23 mm. Refined grain size, weakened basal texture and promoted mechanical property and formability were obtained via suitable alloying addition method. A massive amount of secondary phase particles with uniform distribution were induced by TRC process, which leads to further improvement of comprehensive performance. Therefore, the strengthening mechanisms for TRC-ZAEX2100 alloy sheets are related to solution strengthening, precipitate strengthening and grain boundary strengthening. The in-plane anisotropy of mechanical properties is dominated by distributions of Schmid factors for basal slips, which is ascribed to the variation of texture characterization. Ultimately, such developed alloys are expected to make comprehensive performance meet the increasing needs of various industries. (paper)

[en] A cell module of linear transformer driver (LTD), based on Blumlein pulse forming network (PFN), is designed. Two Blumlein PFNs with 20 Ω resistance are symmetrically connected with the LTD's primary coil. The connection reduces the design difficulty of PFN and improves the output pulse quality. High Jantage pulses are derived from a 10 Ω matching load connected with the LTD's secondary coil. The output pulse of the LTD module is about 200 ns in duration with a rise time of about 55 ns and a flat top of about 100 ns. (authors)

[en] Hot compression test of Mg–4Zn–0.8Ca alloy was conducted at 200 °C–350 °C and 0.002 s⁻¹–1 s⁻¹ to investigate constitutive equation and processing map of Mg–4Zn–0.8Ca alloy. Experimental results indicate the stress of Mg–4Zn–0.8Ca is enhanced with declining temperature and increased strain rate. Deviations between the calculated and measured flow stresses are reduced when the hot compression constitutive equation of Mg–4Zn–0.8Ca is optimized into a piecewise mode with different n and lnA values at 200 °C–250 °C and 300 °C–350 °C. It is found that the dramatic reduction of n value with increasing deformation temperatures above 250 °C is related to the dramatic increase of the strain rate sensitivity index which is attributed to the activation of pyramidal $⟨\mathbf{c}+\mathbf{a}⟩$ slips. Moreover, the optimal processing condition lies in T = 335 °C–350 °C and $\stackrel{\dot{}<!--\; ??\; -->}{\mathrm{\epsilon <!--\; ??\; -->}}=0.002\text{--}0.035{\mathrm{s}}^{-<!--\; ???\; -->1}.$ The typical microstructures in the instability domain are elongated homogenized microstructure, while the samples in the stability domain present DRXed characteristics. (paper)