High-Power in-Band Pumped a-Cut Ho:Yap Laser

We report the continuous wave and acousto-optically Q-switched operation of an in-pumped a-cut Ho:YAP laser at room temperature. We obtained a continuous-wave output power of 17.2 W at 2118 nm under an absorbed pump power of 29.8 W, corresponding to a slope efficiency of 63.2 %. For the Q-switched mode, we achieved a maximum pulse energy of about 1.7 mJ and a minimum pulse width of 24 ns at a repetition rate of 10 kHz, resulting in a peak power of 70.8 kW.     

Kernel formula approach to the universal Whitham hierarchy

Based on the kernel formula proposed by Carroll and Kodama, we derive the dispersionless Hirota equations of the universal Whitham hierarchy. We also verify the associativity equations in this hierarchy from the dispersionless Hirota equations and give a realization of the associative algebra with the structure constants expressed in terms of residue formulas.     

On non-uniform hyperbolicity assumptions in one-dimensional dynamics

We give an essentially equivalent formulation of the backward contracting property, defined by Juan Rivera-Letelier, in terms of expansion along the orbits of critical values, for complex polynomials of degree at least 2 which are at most finitely renormalizable and have only hyperbolic periodic points, as well as all C ³ interval maps with non-flat critical points.     

Multi-carrier transport properties in p-type ZnO thin films

By the aid of temperature- and magnetic-field-dependent Hall effect measurements, we have extracted the multi-carrier transport information in N-doped and N–In codoped p- ZnO thin films grown on Si substrates through mobility spectrum analysis. It is found that owing to the compensation between free electrons and holes, the two-dimensional hole gas from ZnO/Si interface layers becomes determinant and results in the high p-type conductivity and high hole mobility in the ZnO samples. Compared with N-doping, the N–In codoping introduces many In donors and increases acceptor incorporation, as well as enhancing the free hole mobility due to the short-range dipole-like scattering.     

Effect of Cr on the wetting in Cu/graphite system

The isotherm wetting and spreading behaviors of the molten Cu-Cr alloys with 0.5, 1.0 and 2.0 at.% Cr on porous graphite substrates were investigated at 1373 K in a flowing Ar atmosphere using a modified sessile drop method. The wettability improves with increasing Cr content in the alloy as a result of phase transition from Cr₃C₂ to more wettable and metallic-like Cr₇C₃ developed at the interface. The spreading kinetics are controlled by the interfacial reaction in the early stage and the diffusion of Cr from the drop bulk to the triple junction in the later stage together with a transition in the intermediate stage.     

Electrodeposited molybdenum-doped Co3O4 nanosheet arrays for high-performance and stable hybrid supercapacitors

Journal of Solid State Electrochemistry - Long-cycle stability and high-energy density are big challenges for developing high-performance hybrid supercapacitor (HSC) electrode materials. In this...     

Study of Fe/Mo multilayer systems by SFM and AES

Received: 13 August 1998 / Published online: 10 February 1999