Half-monopoles in the Yang-Mills theory

Using a gauge-invariant characterization of monopoles defined via their centres, we investigate the generic topological field pattern for the three-dimensional Yang-Mills theory. This leads to field patterns with one-half winding number. After presenting the main features through the simpler case of half-vortices, we consider half-monopoles in detail.     

脉冲变压器锥形高压绕组电压分布实验研究

 对脉冲变压器锥形高压绕组进行了脉宽为1 μs，500 ns及100 ns三种不同脉宽的单脉冲实验，研究了不同输入条件下绕组中的电压分布特性，比较了空心、加内铁芯和加内外铁芯三种不同结构绕组中的对地电压及匝间电压的分布曲线。实验结果表明：在高频冲击电压条件下，脉冲变压器锥形高压绕组中的电压呈现非线性分布且存在明显的振荡过程，导致绕组首端的电压梯度增大，伴随脉宽减小电压波形发生明显畸变，冲击电压以波的形式在绕组中传播，从而引起匝间电压按照正弦规律起伏变化，匝间电压的极值通常出现在绕组首末端，加入铁芯有助于抑制电压谐振但同时增大了匝间电压。     

Cycle factorizations of powers of odd cycles

Letm 3 be an odd integer and let k, n, and s 3 be positive integers. We present sufficient conditions for the existence of C-factorizations of (C_m^k)ⁿ. We show these conditions to be necessary when m is prime. © 1999 John Wiley & Sons, Inc. J Combin Designs 7: 173–183, 1999     

Which sets are images of disk-algebra functions?

We give a characterization of those compact sets in the plane with finitely many holes that are images of disk-algebra functions. We also show that the image of the closed unit disk via a polynomial is, in general, not polynomially convex.