Topological phase transition in the quench dynamics of a one-dimensional Fermi gas

We study the quench dynamics of a one-dimensional ultracold Fermi gas in an optical lattice potential with synthetic spin-orbit coupling. At equilibrium, the ground state of the system can undergo a topological phase transition and become a topological superfluid with Majorana edge states. As the interaction is quenched near the topological phase boundary, we identify an interesting dynamical phase transition of the quenched state in the long-time limit, characterized by an abrupt change of the pairing gap at a critical quenched interaction strength. We further demonstrate the topological nature of this dynamical phase transition from edge-state analysis of the quenched states. Our findings provide interesting clues for the understanding of topological phase transitions in dynamical processes, and can be useful for the dynamical detection of Majorana edge states in corresponding systems.Comment: 7 pages, 5 figure

Tunable Frequency Comb Generation from a Microring with a Thermal Heater

We demonstrate a novel comb tuning method for microresonator-based Kerr comb generators. Continuously tunable, low-noise, and coherent comb generation is achieved in a CMOS-compatible silicon nitride microring resonator.Comment: submitted to CLEO201

LEG STIFFNESS CHANGES IN DROP JUMPS WITH DIFFERENT STRETCH AMPLITUDE

The purpose of this study was to investigate the adjustment of leg stiffness and the relative electromyography (EMG) magnitude of different phases with shallow and deep drop jump (DJ) in order to understand the neuromuscular and contraction characteristics of different stretch amplitudes of SSC movement. There were 12 subjects tested in this experiment including jumpers and volleyball players whose ages are 20.5±1.93, heights are 181.01±6.23cm and weights are 71.95±4.93Kg. Kistler forceplatform, PEAK high speed video camera and EMG Biovision system were used to record the ground reaction force, kinematics data and the EMG signals of gastrocnemius and rectus femoris. The results of this study were that the leg stiffness between two different drops jump had the significant difference at the concentric and transmission phases in the progressive loads (

Optimizing de novo transcriptome assembly from short-read RNA-Seq data: a comparative study

With the fast advances in nextgen sequencing technology, high-throughput RNA sequencing has emerged as a powerful and cost-effective way for transcriptome study. De novo assembly of transcripts provides an important solution to transcriptome analysis for organisms with no reference genome. However, there lacked understanding on how the different variables affected assembly outcomes, and there was no consensus on how to approach an optimal solution by selecting software tool and suitable strategy based on the properties of RNA-Seq data. To reveal the performance of different programs for transcriptome assembly, this work analyzed some important factors, including k-mer values, genome complexity, coverage depth, directional reads, etc. Seven program conditions, four single k-mer assemblers (SK: SOAPdenovo, ABySS, Oases and Trinity) and three multiple k-mer methods (MK: SOAPdenovo-MK, trans-ABySS and Oases-MK) were tested. While small and large k-mer values performed better for reconstructing lowly and highly expressed transcripts, respectively, MK strategy worked well for almost all ranges of expression quintiles. Among SK tools, Trinity performed well across various conditions but took the longest running time. Oases consumed the most memory whereas SOAPdenovo required the shortest runtime but worked poorly to reconstruct full-length CDS. ABySS showed some good balance between resource usage and quality of assemblies. Our work compared the performance of publicly available transcriptome assemblers, and analyzed important factors affecting de novo assembly. Some practical guidelines for transcript reconstruction from short-read RNA-Seq data were proposed. De novo assembly of C. sinensis transcriptome was greatly improved using some optimized methods