Generation of a uniform-square focal spot by a compound lens for solar concentration applications.

This paper describes a compound lens for solar photovoltaic system applications, which is composed of a front aspheric or Fresnel surface and a back array of concave surfaces. In contrast to earlier designs, the proposed method can simultaneously focus and shape sun light into a uniform-square pattern on the solar cell. For a square solar cell, this approach can maximize the solar cell's opto-electric conversion efficiency by enhancing the concentrated pattern's uniformity. In this article, the theoretical models of the beam shaping focused lens is derived and then compared with experimental data. The tolerance in assembling the component of the concentrator is also analyzed and the corresponding simulation and experimental results are discussed in detail.

Hollow Ag/Pd triangular nanoplate: a novel activator for electroless nickel deposition.

Hollow Ag/Pd triangular nanoplates have been successfully prepared by a galvanic displacement reaction, in which added Pd(2+) ions react with Ag triangular nanoplates as templates. By altering the sizes of the Ag nanotemplates, Ag/Pd triangular nanoplates of different sizes can be prepared. Additionally, the large alloy nanoplates show maximum electrochemical activity when Ag/Pd triangular nanoplates of different sizes are applied as new activators for electroless nickel deposition.

High Activity of Hexagonal Ag/Pt Nanoshell Catalyst for Oxygen Electroreduction.

Hexagonal Ag/Pt nanoshells were prepared by using a hexagonal Ag nanoplate as the displacement template and by introducing Pt ions. The prepared Ag/Pt nanoshells played the role of an electrocatalyst in an oxygen reduction process. Compared to spherical Pt and Ag/Pt nanoparticles, the hexagonal Ag/Pt nanoshells showed higher activity for oxygen electroreduction.