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Today the energy storage systems are still encumbering, therefore it is useful to think about the optimization of a railgun system in order to achieve the best performance with the lowest energy input. In this paper, an optimal design method considering 5 parameters is proposed to improve the energy conversion efficiency of a simple railgun. In order to avoid costly trials, the field- circuit method is employed to analyze the operations of different structural railguns with different parameters respectively. And the orthogonal test approach is used to guide the simulation for choosing the better parameter combinations, as well reduce the calculation cost. The research shows that the proposed method gives a better result in the energy efficiency of the system. To improve the energy conversion efficiency of electromagnetic rail launchers, the selection of more parameters must be considered in the design stage, such as the width, height and length of rail, the distance between rail pair, and pulse forming inductance. However, the relationship between these parameters and energy conversion efficiency cannot be directly described by one mathematical expression. So optimization methods must be applied to conduct design. In this paper, a rail launcher with five parameters was optimized by using orthogonal test method. According to the arrangement of orthogonal table, the better parameters’ combination can be obtained through less calculation. Under the condition of different parameters’ value, field and circuit simulation analysis were made. The results show that the energy conversion efficiency of the system is increased by 71.9 % after parameters optimization.

A measurement of the production of three isolated photons in proton–proton collisions at a centre-of-mass energy $\sqrt{s}$ = 8 TeV is reported. The results are based on an integrated luminosity of 20.2 fb$^{−1}$ collected with the ATLAS detector at the LHC. The differential cross sections are measured as functions of the transverse energy of each photon, the difference in azimuthal angle and in pseudorapidity between pairs of photons, the invariant mass of pairs of photons, and the invariant mass of the triphoton system. A measurement of the inclusive fiducial cross section is also reported. Next-to-leading-order perturbative QCD predictions are compared to the cross-section measurements. The predictions underestimate the measurement of the inclusive fiducial cross section and the differential measurements at low photon transverse energies and invariant masses. They provide adequate descriptions of the measurements at high values of the photon transverse energies, invariant mass of pairs of photons, and invariant mass of the triphoton system. Physics letters / B 781, 55 - 76 (2018). doi:10.1016/j.physletb.2018.03.057 Published by North-Holland Publ., Amsterdam

Proc. of PANIC 2014, 95 - 98; DESY-PROC-2014-02; ISSN 1435-8077 Contribution to Proceedings

This paper discusses the research progress of micro magnetic generator systems. Micro magnetic generator systems convert energy from the environment to electric energy with advantages as high reliability, high power density, long life time and can be applied to extreme environment. This paper summarizes methods for improving generator performance of micro magnetic generator, including rotational magnetic generator, vibrational magnetic generator and hybrid magnetic generator, analyzes and compares their design and performance, and concludes key technologies and ongoing challenges for further progress. The paper is instructive and meaningful to for research work of related field.

The yttrium aluminum garnet (YAG) long fibers were prepared by the sol-gel method using aluminum chloride, aluminum powder, yttrium oxide and acetic acid as raw materials. The grain growth law is given by Dn – D0n = Kt (D0 = initial grain size, D = average grain size at time t, n = grain growth exponent and K = reaction constant). The grain growth exponent and activation energy of YAG fibers are ≈ 3 and 200 kJ/mol, respectively. The grain-growth behaviors of YAG were influenced by experimental conditions such as raw materials, initial particle size, initial particle distribution, etc.

Current energy conservation and emissions reduction strategies in iron and steel industry were reviewed. Since foundry industry is one of the major source of energy consumption and pollution emission (especially CO2), issues concerning energy-saving and emission-reduction have been raised by governments and the industry. Specialists from around the world carried out multidimensional analyses and evaluation on the potentials in energy conservation and emissions reduction in iron and steel industry, and proposed various kinds of analyzing models. The primary measures mainly focus on the targeted policies formulation and also on clean and high-efficient technologies development. The differences and similarities in energy conservation and emission reduction in foundry industry between China and other countries were discussed, while, the future development trend was also pointed out.

For the design of three-stage electromagnetic coilgun, many parameters and their relations must be considered at the same time. However, there is no complete mathematical model to describe the relationship between these parameters and energy conversion efficiency of the coil launcher system. In this paper, using orthogonal test approach we consider the influence of 11 parameters to improve the energy conversion efficiency of a three-stage coilgun. Moreover, for the 11 parameters, another three neighboring values of the actual value are considered. According to the different 64 simulations arranged by orthogonal test approach, the 64 groups of muzzle velocity calculated by circuit equations can be analyzed to obtain a better parameters’ combination. For the solution of circuit simulations, an improved current filament method is proposed. To validate the optimal design, we manufacture the prototype and the improved one. The experimental results indicate that the optimal design method is effective.

Single-layer ceramic fuel cells consisting of Li0.15Ni0.45Zn0.4O2, Gd0.2Ce0.8O2 and a eutectic mixture of Li2CO3, Na2CO3 and K2CO3, were fabricated through extrusion-based 3D printing. The sintering temperature of the printed cells was varied from 700 °C to 1000 °C to identify the optimal thermal treatment to maximize the cell performance. It was found that the 3D printed single-layer cell sintered at 900 °C produced the highest power density (230 mW/cm2) at 550 °C, which is quite close to the performance (240 mW/cm2) of the single-layer cell fabricated through a conventional pressing method. The best printed cell still had high ohmic (0.46 Ω·cm2) and polarization losses (0.32 Ω·cm2) based on EIS measurements conducted in an open-circuit condition. The XRD spectra showed the characteristic peaks of the crystalline structures in the composite material. HR-TEM, SEM and EDS measurements revealed the morphological information of the composite materials and the distribution of the elements, respectively. The BET surface area of the single-layer cells was found to decrease from 2.93 m2/g to 0.18 m2/g as the sintering temperature increased from 700 °C to 1000 °C. The printed cell sintered at 900 °C had a BET surface area of 0.34 m2/g. The fabrication of single-layer ceramic cells through up-scalable 3D technology could facilitate the scaling up and commercialization of this promising fuel cell technology.