可扩展的冲击—接触并行计算研究

冲击—接触计算模型在汽车碰撞、金属成型等的模拟计算中有着广泛的应用，鉴于冲击—接触计算过程复杂和计算量大，本文在分布式可扩展的并行计算平台上，设计并实现了冲击—接触的并行计算。算例证明，计算平台稳定可靠，算法简单实用，且具有较好的并行效率和可扩展性。     

Ionic‐Liquid‐Grafted Rigid Poly(p‐Phenylene) Microspheres: Efficient Heterogeneous Media for Metal Scavenging and Catalysis

Novel guanidinium ionic liquid‐grafted rigid poly(p‐phenylene) (PPPIL) microspheres have been developed for metal scavenging and catalysis. The noble‐metal nanoparticles supported on the microspheres surface can be used as efficient heterogeneous catalysts. The combination of nanoparticles and ionic liquid fragments on the microsphere surfaces enhance the activity and durability of the catalyst. The PPPIL ? Pd⁰ catalyst has been tested in the Suzuki cross‐coupling reaction, and exhibits much higher catalytic activity than Pd catalysts supported on porous polymer matrices. The PPPIL ? Pd⁰ catalyst can be recycled at least for nine runs without any significant loss of activity. The present approach may, therefore, have potential applications in transition‐metal‐nanocatalyzed reactions.     

Regio- and enantioselective intermolecular hydroacylation: substrate-directed addition of salicylaldehydes to homoallylic sulfides

We report a Rh-catalyzed, regio- and enantioselective intermolecular olefin hydroacylation under mild conditions. Hydroacylations between homoallylic sulfides, containing a substrate-bound directing group, and salicylaldehyde derivatives occur in the presence of a spiro-phosphoramidite ligand, (R)-SIPHOS-PE, to give α-branched ketones in >20:1 selectivity and up to 97% ee. Our conditions are also applicable to the asymmetric intermolecular hydroacylation of 1,2-disubstituted olefins.     

In-band pumped Er:YAG ceramic laser with 11 W of output power at 1645 nm

We report on a high power polycrystalline Er:YAG ceramic laser in-band pumped by a cladding-pumped Er, Yb fiber laser wavelength locked at 1532 nm with a volume Bragg grating. Using 1.0 at % Er³⁺-doped ceramic as the gain medium and an output coupler of 10% transmission, the laser had a threshold pump power of ∼1.5 W and generated 11 W of continuous-wave output at 1645 nm for 23.3 W of incident pump power at 1532 nm, corresponding to a slope efficiency with respect to incident pump power of 51%.     

The atom-photon entanglement of a two-level system embedded in double-band photonic band edge

The entanglement of a two-level atom with its spontaneously emitted photon embedded in double-band anisotropic photonic crystal has been investigated via the method of the quantum entropy. Different from the case in an isotropic crystal or in vacuum, the entanglement has symmetrical properties and much slower entanglement rate near the two band edges. Moreover, as a result of the atom-photon bound states by the virtue of the localization around the emitting atom, the degree of the entanglement gradually increases, achieves the maximum and then sharply reduces to zero on the boundary of forbidden band gap as the atomic frequency moves from the center of the band gap to either of the band edges.     

Double dark resonances and the dispersion properties in a four-level inverted-Y atomic system

The electromagnetically induced transparency (EIT) and its dispersion properties in a four-level inverted-Y atomic system are investigated. The absorption spectrum of a weak probe field shows two EIT windows (dark resonances) whose location, width, and depth can be controlled by manipulating the parameters of the coupling fields; the corresponding dispersion properties are also measured by using a Mach-Zehnder interferometer. The experimental measurements agree well with the theoretical calculations. This kind of system can find important applications in two-channel quantum communication and information storage.     

Analysis of a combined mixed finite element and discontinuous Galerkin method for incompressible two‐phase flow in porous media

We analyze a combined method consisting of the mixed finite element method for pressure equation and the discontinuous Galerkin method for saturation equation for the coupled system of incompressible two‐phase flow in porous media. The existence and uniqueness of numerical solutions are established under proper conditions by using a constructive approach. Optimal error estimates in L²(H¹) for saturation and in L ^∞ (H(div)) for velocity are derived. Copyright © 2013 John Wiley & Sons, Ltd.     

塞曼效应实验数据分析与处理方法改进

利用CCD观测系统获取了塞曼效应实验分裂的干涉圆环图像,通过计算机软件编写灰度获取程序,将传统的测微目镜测量法和画圆法测量干涉圆环直径改进为利用计算机程序自动获取干涉圆环数据,并通过编写的数据处理程序对获得的数据自动计算和分析,简化了数据分析与处理过程并提高了实验结果的精度.