A Categorical Structure for the Virtual Braid Group

This article gives a new interpretation of the virtual braid group in terms of a strict monoidal category SC that is freely generated by one object and three morphisms, two of the morphisms corresponding to basic pure virtual braids and one morphism corresponding to a transposition in the symmetric group. This point of view makes many relationships between the virtual braid group and the pure virtual braid group apparent, and makes representations of the virtual braid groups and pure virtual braid groups via solutions to the algebraic Yang–Baxter Equation equally transparent. In this categorical framework, the virtual braid group has nothing to do with the plane and nothing to do with virtual crossings. It is a natural group associated with the structure of algebraic braiding.     

All‐optical virtual private network in passive optical networks

We review recent progress on all‐optical virtual‐private‐network (VPN) schemes in passive optical networks (PONs). PON is a promising candidate in future access areas to provide broadband services with low cost. With all‐optical virtual private network (VPN) function, PON can support efficient internetworking among end users with dedicated optical channels, thus enabling guaranteed bandwidth and enhanced security at the physical layer. Here, we discuss and compare existing schemes of all‐optical VPNs in time‐division‐multiplexed (TDM) PONs, and also recently proposed schemes for deployment in wavelength‐division‐multiplexed (WDM) PONs and two‐stage TDM/WDM PONs.     

High performance LCD for augmented reality and virtual reality displays

For augmented reality and virtual reality displays, high-resolution density, high luminance, and fast response time are critically needed. High-resolution density helps eliminate the screen-door effect; high luminance and fast response time enable low duty ratio operation, which plays a key role for suppressing image blurs. By using a low viscosity material and new diamond-shaped electrode configuration, we demonstrate a fringe field switching liquid crystal display, abbreviated as d-FFS LCD, with high transmittance, fast grey-to-grey response time, low operation voltage, wide viewing angle, and indistinguishable colour shift and gamma shift. We also investigate the rubbing angle (α) effects on transmittance and response time. When α = 0°, the virtual wall effect is strong, resulting in fast response time but compromised transmittance. When α ≥ 1.2°, the virtual walls disappear, as a result, the transmittance increases dramatically, but the trade-off is in slower response time.     

15—20mA负氢离子源的设计与加工

离子源是强流质子回旋加速器的核心设备之一, 它的性能指标对最终束流大小和质量都有重大影响. 文章介绍了一种运用于强流质子回旋加速器上的多峰场负氢离子源的设计与加工情况, 该离子源主要是通过深入研究高密度等离子体产生技术、长寿命大直流灯丝电子发射技术、磁约束技术、虚拟过虑技术、残留气体与电子剥离的控制技术, 以及离子引出技术等, 在中国原子能科学研究院原有10mA离子源基础上建立负氢离子源, 实验研究低能、强流束的实验匹配与调试技术, 将平均引出束流提高到15—20mA.     

基于虚拟仪器三维多涡卷混沌电路的研究

介绍了基于虚拟仪器的三维多涡卷混沌系统,给出了三维多涡卷混沌电路的实验方案.利用此方案进行实验,证明此实验系统具有良好的实验效果.     

高效强流径向分离腔振荡器研究

根据同轴虚阴极的结构特点,提出了一种紧凑型径向分离腔振荡器,该径向分离腔的特点是输入电子束的电流可以很大,从而可以得到较高的微波输出功率. 综合考虑影响微波输出的各种因素,在电子束为410kV,电流为35kA的条件下,模拟得到的平均功率大于50GW,频率为146GHz,电子束功率效率达到348%. 关键词： 径向分离腔 高功率微波 同轴虚阴极 电子束分布     

Discussion of “Virtual age,is it real?”

In this note, some point of views on virtual ages are presented in terms of the discussion paper written by Finkelstein and Cha, which include generalized stochastic order‐based virtual ages, system‐level virtual ages, virtual ages in Weibull distribution and repair degrees with virtual ages. Finally, some possible future researches on virtual ages are described.     

Virtual element methods for parabolic problems on polygonal meshes

The virtual element method (VEM) is a recent technology that can make use of very general polygonal/polyhedral meshes without the need to integrate complex nonpolynomial functions on the elements and preserving an optimal order of convergence. In this article, we develop for the first time, the VEM for parabolic problems on polygonal meshes, considering time‐dependent diffusion as our model problem. After presenting the scheme, we develop a theoretical analysis and show the practical behavior of the proposed method through a large array of numerical tests. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 2110–2134, 2015     

Evaluation of the separation performance of polyvinylpyrrolidone as a virtual stationary phase for chromatographic NMR

Polyvinylpyrrolidone (PVP) was used as a virtual stationary phase to separate p‐xylene, benzyl alcohol, and p‐methylphenol by the chromatographic NMR technique. The effects of concentration and weight‐average molecular weight (Mw) of PVP, solvent viscosity, solvent polarity, and sample temperature on the resolution of these components were investigated. It was found that both higher PVP concentration and higher PVP Mw caused the increase of diffusion resolution for the three components. Moreover, the diffusion resolution did not change at viscosity‐higher solvents. Moreover, the three components showed different resolution at different solvents. As temperature increased, the diffusion resolution between p‐xylene and benzyl alcohol gradually increased, and the one between p‐xylene and p‐methylphenol slightly increased from 278 to 298 K and then decreased above 298 K. It was also found that the polarity of the analytes played an important role for the separation by affecting the diffusion coefficient. Copyright © 2014 John Wiley & Sons, Ltd.     

Optimizing Antimicrobial Peptide Dendrimers in Chemical Space

We used nearest‐neighbor searches in chemical space to improve the activity of the antimicrobial peptide dendrimer (AMPD) G3KL and identified dendrimer T7 , which has an expanded activity range against Gram‐negative pathogenic bacteria including Klebsiellae pneumoniae, increased serum stability, and promising activity in an in vivo infection model against a multidrug‐resistant strain of Acinetobacter baumannii. Imaging, spectroscopic studies, and a structural model from molecular dynamics simulations suggest that T7 acts through membrane disruption. These experiments provide the first example of using virtual screening in the field of dendrimers and show that dendrimer size does not limit the activity of AMPDs.