Direct energy conversion of plasma energy

An application of ambipolar potential in a magnetized plasma is proposed for direct energy conversion. Analyses of a model device for 20-MW-per-unit-length (without considering end loss) and 14-MW-per-unit-length (with the end loss) are shown. The plasma density profile, the potential distribution in the device, and the voltage-current characteristics are obtained on the basis of the Poisson continuity equation system. As an example, a theoretical energy loss by neutral particles, which should not affect the total efficiency much. Experiments with a small thermal ionization-type device were performed wherein the relations of output voltage versus current and power versus impedance were acquired. the experimental results are compared with the theoretical and a qualitative agreement is obtained     

Topological resonance energy,bond resonance energy,and circuit resonance energy

Circuit resonance energy (CRE) is a key quantity that links energetic and magnetic criteria of aromaticity for a polycyclic π‐system. Topological resonance energy (TRE) correlates well with the sum of CREs for an entire π‐system. We found that bond resonance energy (BRE), so far defined to estimate the degree of kinetic stability for a polycyclic π‐system, also correlates very well with the corresponding quantity defined with CREs. These findings justify the view that graph‐theoretical quantities, such as TRE and BRE, can be used safely even though they rely on unrealistic reference structures. Copyright © 2007 John Wiley & Sons, Ltd.     

Near-thermal energy width of moderated high energy positrons

More than 10^?7 of the positrons emitted by ¹¹C (produced by proton bombardment of boron) emerge from the room-temperature boron target with a low energy (less than 1 eV) and a measured energy width of (0.100+0.010) eV.     

Calorimeter energy calibration using the energy conservation law

A new calorimeter energy calibration method was developed for the proposed ILC detectors. The method uses the center-of-mass energy of the accelerator as the reference. It has been shown that using the energy conservation law it is possible to make ECAL and HCAL cross calibration to reach a good energy resolution for the simple calorimeter energy sum.      

Potential energy curves and dissociation energy of SiCl

The true potential energy curves have been constructed for the ground and excited electronic states of SiCl by the method of Lakshman and Rao. The dissociation energy of the ground state has been estimated by fitting the Hulburt-Hirschfelder function to the true potential energy curves. The dissociation energy thus obtained is 33,500 cm^-1 (4.15 eV), which is in good agreement with the value of 4.5±0.5 eV reported by Gaydon.     

Dynamical dark energy with a constant vacuum energy density

We present a holographic dark-energy model in which the Newton constant GN$G_N$ scales in such a way as to render the vacuum energy density a true constant. Nevertheless, the model acts as a dynamical dark-energy model since the scaling of GN$G_N$ goes at the expense of deviation of concentration of dark-matter particles from its canonical form and/or of promotion of their mass to a time-dependent quantity, thereby making the effective equation of state (EOS) variable and different from −1 at the present epoch. Thus the model has a potential to naturally underpin Dirac's suggestion for explaining the large-number hypothesis, which demands a dynamical GN$G_N$ along with the creation of matter in the universe. We show that with the aid of observational bounds on the variation of the gravitational coupling, the effective-field theory IR cutoff can be strongly restricted, being always closer to the future event horizon than to the Hubble distance. As for the observational side, the effective EOS restricted by observation can be made arbitrary close to −1, and therefore the present model can be considered as a “minimal” dynamical dark-energy scenario. In addition, for nonzero but small curvature (|Ω_k0|?0.003)$(|{\Omega }_{k0}|?0.003)$, the model easily accommodates a transition across the phantom line for redshifts z?0.2$z?0.2$, as mildly favored by the data. A thermodynamic aspect of the scenario is also discussed.     

高能脉冲X射线能谱测量

给出了高能脉冲X射线能谱测量的基本原理及实验结果.采用Monte-Carlo程序计算了高能光子在能谱仪中每个灵敏单元内的能量沉积,利用能谱仪测量了"强光Ⅰ号"加速器产生的高能脉冲X射线不同衰减程度下的强度,求解得到了具有时间分辨的高能脉冲X射线能谱,时间跨度57ns,时间步长5ns,光子的最高能量3.0MeV,平均能量1.04MeV,能量在0.2—0.9MeV之间的光子数目最多,占46.5%.也利用二极管的电压电流波形理论计算了光子的能谱,并与利用能谱仪测得的能谱进行了比较,两种方法所得结果基本一致.     

The peierls energy and kink energy in fcc metals

In fcc crystals, dislocations are dissociated on the {111} glide plane into pairs of partial dislocations. Since each partial interacts individually with the Peierls potential and is coupled to its neighbour by a stacking fault, periodic variations in the separation distance d of the partials occur when dislocations running along closed packed lattice directions are displaced. This can drastically reduce the effective Peierls stress. By using the Peierls model the structure of 0°, 30°, 60° and 90° dislocations in a typical fcc metal with the elastic properties of Cu and a stacking-fault energy γ₀ in the interval 0.04?≤?γ₀?≤?0.05?J/m² was studied, and the magnitude of the Peierls energy ΔE _P and the resulting kink energies E _K were determined. Since the energies involved are of the order of 10^?3?eV/b or less, their magnitude cannot be asserted with high confidence, considering the simplifying assumptions in the model. The difference in the changes of the core configuration during displacement of dislocations of different orientations should, however, be of physical significance. It is found that a dissociated 60° dislocation generally has a higher effective Peierls energy than a screw dislocation, but the reverse is true for the kink energy, at least in Cu.