串列加速器头部电极改进方案

通过改变头部电极的局部形状来改善头部电场, 运用Poisson程序计算几种可能形状下表面电场的分布, 并以此给出最佳的改进方案.     

Excitation of plant growth in dormant temperature by steady magnetic field

Experimental results of applying a steady magnetic field (20 and 30 mT) on agricultural plants reveal that their growth is more than that of control plants. Considering that these plants have ferritin cells, and each ferritin cell has 4500 Fe atoms, it is obvious that they have an outstanding role in the plants’ growth. As the last spin magnetic moment (SMM) of the Fe atom posed to an external magnetic field (EMF), the composition of SMM and EMF create an oscillator in the system. Then we have a moment of force on ferritin cells. This oscillator exerts its energy, then damps and finally locates in the field direction. The relaxed energy increased the internal temperature (i.e., the effective temperature of the magnetic spin system of plant) so that it is situated in a proper temperature for growing. This phenomenon (temperature increasing) occurs in the initial minutes of applying the magnetic field. So it depends on the number of times of locating the plant in magnetic field in a day (n). If this number (n) passes the critical value, the plant reaches a burning temperature and growth is perturbed. In this paper, the plant growth rate and critical temperature in a steady magnetic field were investigated and formulated theoretically. An innovative result in this research is as follows: if a plant's environment was in the dormant temperature, we could increase the internal temperature of the plant by applying a magnetic field n times in a day (for growth).     

相对论粒子在地球偶极磁场中辐射谱的数值计算

从运动的荷电粒子产生的流密度出发,研究了在地球偶极磁场中运动的相对论性荷电粒子的辐射能量谱,并对其进行数值计算.分析了相对论性荷电粒子在地球偶极磁场这种特殊磁场中的辐射特点.     

Mössbauer effect study of the decagonal quasicrystal Al65Co15Cu20

The ⁵⁷Fe Mössbauer effect study at 5.0 K and in an external magnetic field of 9.0 T on a high-quality stable decagonal quasicrystal Al₆₅Co₁₅Cu_19.9Fe_0.1 is presented. It is shown that the iron atoms are located in two distinct classes of sites. The values of the principal component of the electric field gradient tensor and the asymmetry parameter at these sites are, respectively, ?1.90(10)?×?10²¹ V/m², 0.97(15) and ?3.95(12)?×?10²¹ V/m², 0.00(17).     

Some applications of thermal field theory to quark-gluon plasma

We briefly introduce the thermal field theory within imaginary time formalism, the hard thermal loop perturbation theory and some of its applications to the physics of the quark-gluon plasma, possibly created in relativistic heavy-ion collisions     

The Nature of Electronic Charge

Advances in gauge theories and unified theories have not thrown light on the meaning of electron. The problem of the origin of electronic charge is made precise, new insights gained from Weyl space are summarized, and the origin of charge in terms of fractional spin is suggested. A new perspective on the abelian Chern-Simons theory is presented to explain charge.     

Magnetized cosmological models in bimetric theory of gravitation

Bianchi type-III magnetized cosmological model when the field of gravitation is governed by either a perfect fluid or cosmic string is investigated in Rosen’s [1] bimetric theory of gravitation. To complete determinate solution, the condition, viz., A=(BC) ⁿ , where n is a constant, between the metric potentials is used. We have assumed different equations of state for cosmic string [2] for the complete solution of the model. Some physical and geometrical properties of the exhibited model are discussed and studied.     

排列形状及阵列数目对纳米导线阵列场发射性能的影响

为了进一步研究纳米导线阵列的排列形状以及阵列数目对其场发射行为的影响，利用镜像悬浮球模型对正方形以及六边形排列的纳米导线阵列的场发射行为进行计算与模拟，近似的得到纳米导线阵列的场发射增强因子满足如下的变化趋势：β=h/ρ(1/1+W)+1/2(1/1+W)²+3,其中h为纳米导线的高度，ρ为纳米导线的半径，W是以R为自变量的函数，R为纳米导线阵列的间距.结果显示纳米导线阵列的排列形状对其场发射性能的影响较小，而阵列间距则是影响场发射性能的关键因素：当R<R₀时，场发射增强因子随着阵列间距的减小而急剧减小；当R>R₀时，场发射增强因子基本不变，其中R₀为导线阵列场发射的最佳间距.进一步研究表明改变纳米导线阵列的数目基本不会改变阵列的场发射性能随间距的变化趋势，但是随着阵列数目的增加，R₀会有一定程度的减小，场发射增强因子也会降低. 关键词： 纳米导线 场发射 增强因子 阵列数目     

径向剪切干涉法综合诊断光束质量研究

 为了解决高功率激光装置光束质量诊断系统的自验证问题，研究了基于空间相位调制的径向剪切干涉法综合诊断光束质量的实验应用。该方法理论上只需一台干涉仪且从单幅干涉图中获取光束的近场、相位和远场分布信息。实验结果表明，目前可以得到高分辨率的相位分布，由测量近场和相位恢复出的远场同CCD直接测量得到的远场形态相同，环围能量比曲线相当吻合，不足之处在于只能提取近场较低空间频率成分，还达不到CCD直接测量的空间分辨水平。     

脉冲磁场处理对碳纳米管掺杂MgB2线材临界电流密度的影响

对碳纳米管(CNT)掺杂MgB₂超导体磁场处理后的行为进行了研究. 结果表明，CNT掺杂MgB₂超导体经5T脉冲磁场处理后临界电流密度J_c(H)在低磁场下提高了2—3倍，高场下提高一个数量级以上，扫描电镜结果显示CNT沿着处理磁场方向规则排列并且成为MgB₂基体的形核中心和高效的磁通钉扎中心. 关键词： 2')" href="#">MgB₂ 碳纳米管 脉冲磁场处理