We designed new atmospheric pressure plasma device, to explore appropriate voltage of plasma treatment that promote traits and yield of tomato, tomato seeds were treated by plasma at 4760 to 6800 V, and traits and yield of tomato were observed. The results showed that the effects of different voltage plasma treatments on seed germination were not the same. The bloom times, the height, the caulis, the extent of the plants and the average weight, length，diameter of each fruit in the seven treatment groups from 4760 to 6800 V were increased distinctly. The tomato yields of seven different plasma voltage treated groups were increased than the untreated (CK). In most indexes of our tests, effects of (5440 ~ 6120 V) plasma voltage treatments were better than of other voltages, the best was 6120 V plasma voltage treatment. So the tomato yield increase and the most the botany properties of the tomato are improved. The discharges were not uniform and the powers were lower in low voltages (4760 ~ 5100V), and the discharge powers were higher in high voltages (6460 ~ 6800V). There was a step unaltered violet blue light from 5440V to 6120V, it was nearly uniform discharges, it maybe due to the energy of the electron and the active air particles in the plasma increasing with atmospheric plasma voltage adding, more electric charges are produced per unit time and cannot be neutralized at once, which can strengthen the reaction between the active air particles and seeds. The active air particles and ultraviolet radiation can penetrate into the capsule of the seeds，accelerate to decompose the inner nutriment of the seeds, reduce relative penetrability of cell velum, improve the activities of the root of the tomato seedling. Test data of fruit yield of the tomato are consistent with the statistical regressive line.

We have observed relaxation oscillations in an argon capacitive discharge connected to a peripheral grounded chamber through a slot with dielectric spacers. The oscillations, observed from time-varying optical emission of the main discharge chamber, show, for example, a high frequency (∼40kHz) relaxation oscillation at 100mTorr, with absorbed power near that for peripheral breakdown, and a low frequency (∼3Hz) oscillation, at higher absorbed power. The high frequency oscillation is found to ignite a plasma in the slot, but usually not in the periphery. We interpret the high frequency oscillations using an electromagnetic model of the slot impedance, coupled to a circuit analysis of the system including the matching network. The model results are in general agreement with the experimental observations and indicate a variety of behaviors dependent on the matching conditions.

PSR J1906+0746 is a nonrecycled strong magnetic field neutron star (NS), sharing the properties of the secondary-formed NS PSR J0737–3039B in the double pulsar system PSR J0737–3039AB. By comparing the orbital parameters of PSR J1906+0746 with those of PSR J0737–3039AB, we conclude that both systems have a similar origin and evolution history, involving an e-capture process for forming the second-born NS, like in the case of PSR J0737–3039B. We expect the companion of PSR J1906+0746 to be a long-lived recycled pulsar with radio beams that currently cannot be observed from Earth. We suggest possible ways to detect its presence. To compare PSR J1906+0746 with PSR J0737–3039, we also present the mass distribution of eight pairs of double NSs and find that in double NSs the mass of the recycled pulsar is usually larger than that of the nonrecycled one, which may be the result of accretion.

The structural stabilities, elastic properties and charge transfers of EuX (X = O, S, Se, Te) compounds as a function of pressure are investigated extensively using rst-principles calculations. The ground-state parameters, such as lattice constants, bulk modulus are predicted and compared with the available data, our results are satisfactory. The calculated phase transition pressures from the NaCl-type (B1) structure to the CsCl-type (B2) structure for EuX (X = O, S, Se, Te) also accord with the experiments. Particularly, the elastic constants of EuX (X = O, S, Se, Te) under zero pressure and high pressure are simulated appropriately for the rst time via density functional theory. The softening behaviors of the elastic shear modulus C44 under pressure for the B1 phase of EuX (X = O, S, Se, Te) are captured, which should be responsible for the pressure-induced structural phase transition in the EuX system. It is also suggested that the softening behavior might be induced partly by the p → d and f → d electron transfers of Eu atom under pressure. In addition, the aggregate elastic modulus (B, G, E), Poisson's ratio (σ), Debye temperature ΘD are also successfully obtained for both B1 and B2 phases of EuX.

The structure and pressure-induced phase transitions for CdSe are investigated using firstprinciples calculations. The pressure-induced phase transition sequence WZ/ZB → Rs → Cmcm → CsCl for CdSe is drawn reasonably for the fist time, the corresponding transition pressures are 3.8, 29 and 107 GPa, respectively and the intermediate states between the Cmcm structure and the CsCl structure should exist.