Energy bands and Landau levels of ultracold fermions in the bilayer honeycomb optical lattice

We investigate the spectrum and eigenstates of ultracold fermionic atoms in the bilayer honeycomb optical lattice. In the low energy approximation, the dispersion relation has parabolic form and the quasiparticles are chiral. In the presence of the effective magnetic field, which is created for the system with optical means, the energy spectrum shows an unconventional Landau level structure. Furthermore, the experimental detection of the spectrum is proposed with the Bragg scattering techniques.Comment: To appear in Journal of Modern Optic

Registration-free simultaneous catheter and environment modelling

© Springer International Publishing AG 2016. Endovascular procedures are challenging to perform due to the complexity and difficulty in catheter manipulation. The simultaneous recovery of the 3D structure of the vasculature and the catheter position and orientation intra-operatively is necessary in catheter control and navigation. State-of-art Simultaneous Catheter and Environment Modelling provides robust and real-time 3D vessel reconstruction based on real-time intravascular ultrasound (IVUS) imaging and electromagnetic (EM) sensing,but still relies on accurate registration between EM and pre-operative data. In this paper,a registration-free vessel reconstruction method is proposed for endovascular navigation. In the optimisation framework,the EM-CT registration is estimated and updated intra-operatively together with the 3D vessel reconstruction from IVUS,EM and pre-operative data,and thus does not require explicit registration. The proposed algorithm can also deal with global (patient) motion and periodic deformation caused by cardiac motion. Phantom and invivo experiments validate the accuracy of the algorithm and the results demonstrate the potential clinical value of the technique

SCEM+: Real-Time Robust Simultaneous Catheter and Environment Modeling for Endovascular Navigation

© 2016 IEEE. Endovascular procedures are characterised by significant challenges mainly due to the complexity in catheter control and navigation. Real-time recovery of the 3-D structure of the vasculature is necessary to visualise the interaction between the catheter and its surrounding environment to facilitate catheter manipulations. State-of-the-art intraoperative vessel reconstruction approaches are increasingly relying on nonionising imaging techniques such as optical coherence tomography (OCT) and intravascular ultrasound (IVUS). To enable accurate recovery of vessel structures and to deal with sensing errors and abrupt catheter motions, this letter presents a robust and real-time vessel reconstruction scheme for endovascular navigation based on IVUS and electromagnetic (EM) tracking. It is formulated as a nonlinear optimisation problem, which considers the uncertainty in both the IVUS contour and the EM pose, as well as vessel morphology provided by preoperative data. Detailed phantom validation is performed and the results demonstrate the potential clinical value of the technique

Achieving More with Less: Extra Milers’ Behavioral Influences in Teams

Teams are composed of individual members who collectively contribute to team success. As a result, contemporary team research tends to focus on how team overall properties (e.g., the average of team personality and behavior) affect team processes and effectiveness while overlooking the potential unique influences of specific members on team outcomes. Drawing on minority influence theory (Grant & Patil, 2012), we extend previous teams research by demonstrating that an extra miler (i.e., a team member exhibiting the highest frequency of extra-role behaviors in a team) can influence team processes and, ultimately, team effectiveness beyond the influences of all the other members. Specifically, based on a field study, we report that the extra miler’s behavioral influences (i.e., helping and voice) on team monitoring and backup processes and team effectiveness are contingent on his or her network position in the team, such that the member tends to have stronger influence on team outcomes when he or she is in a central position. We also find that even a single extra miler in a vital position plays a more important role in driving team processes and outcomes than do all the other members. Therefore, our research offers an important contribution to the team literature by demonstrating the disproportionate influences of specific team members on team overall outcomes.postprin

Genes encoding Pir51, Beclin 1, RbAp48 and aldolase b are up or down-regulated in human primary hepatocellular carcinoma

Aim: To reveal new tumor markers and target genes from differentially expressed genes of primary tumor samples using cDNA microarray. Methods: The 33P labeled cDNAs were synthesized by reverse transcription of message RNA from the liver cancerous tissue and adjacent non-cancerous liver tissue from the same patient and used to hybridize to LifeGrid 1.0 cDNA microarray blot containing 8400 known and unique human cDNA gene targets, and an expression profile of genes was produced in one paired human liver tumor tissue. After a global analysis of gene expression of 8400 genes, we selected some genes to confirm the differential expression using Northern blot and RT-PCR. Results: Parallel analysis of the hybridized signals enabled us to get an expression profile of genes in which about 500 genes were differentially expressed in the paired liver tumor tissues. We identified 4 genes, the expression of three (Beclin 1, RbAp48 and Pir51) were increased and one (aldolase b) was decreased in liver tumor tissues. In addition, the expression of these genes in 6 hepatoma cell lines was also showed by RT-PCR analysis. Conclusion: cDNA microarray permits a high throughput identification of changes in gene expression. The genes encoding Beclin 1, RbAp48, Pir51 and aldolase b are first reported that may be related with hepatocarcinoma. Copyright © 2004 by The WJG Press ISSN 1007-9327.published_or_final_versio

Probing deep level centers in GaN epilayers with variable-frequency capacitance-voltage characteristics of AuGaN Schottky contacts

Under identical preparation conditions, AuGaN Schottky contacts were prepared on two kinds of GaN epilayers with significantly different background electron concentrations and mobility as well as yellow emission intensities. Current-voltage (I-V) and variable-frequency capacitance-voltage (C-V) characteristics show that the Schottky contacts on the GaN epilayer with a higher background carrier concentration and strong yellow emission exhibit anomalous reverse-bias I-V and C-V characteristics. This is attributed to the presence of deep level centers. Theoretical simulation of the low-frequency C-V curves leads to a determination of the density and energy level position of the deep centers. © 2006 American Institute of Physics.published_or_final_versio

Violet electroluminescence of AlInGaN-InGaN multiquantum-well light-emitting diodes: Quantum-confined stark effect and heating effect

Electroluminescence (EL) from AlInGaN-InGaN multiquantum-well violet light-emitting diodes is investigated as a function of forward bias. Two distinct regimes have been identified: 1) quantum-confined Stark effect at low and moderately high forward biases; 2) heating effect at high biases. In the different regimes, the low-temperature EL spectra exhibit different spectral features which are discussed in detail. © 2007 IEEE.published_or_final_versio

Probing deep level centers in GaN epilayers with variable-frequency capacitance-voltage characteristics of Au/GaN Schottky contacts

Author name used in this publication: X. M. Tao2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Electrical and FT-IR measurements of undoped N-type INP materials grown from various stoichiometric melts

P-rich, In-rich and Stoichiometric undoped InP melts have been synthesed by phosphorus in-situ injection method. InP crystal ingots have been grown from these melts by Liquid Encapsulated Czochralski (LEC). Samples from these ingots grown from various Stoichiometric melts have been characterized by Hall Effect and Fourier Transform Infrared (FT-IR) spectroscopy measurements respectively. The Hall Effect measurement results indicate that the net carrier concentration of P-inch undoped InP is higher than that of In-rich and Stoichiometric undoped InP materials. FT-IR spectroscopy measurements reveal that there are intensive absorption peaks which have been proved to be hydrogen related indium vacancy complex V InH 4. By comparing FT-IR spectra, it is found that P-rich InP material has the most intensive absorption peak of V InH 4, while In-rich InP material has the weakest absorption peak.published_or_final_versio

Species composition, plant cover and diversity of recently reforested wild lands near Dabao Highway in Longitudinal Range-Gorge Region of Yunnan Province, China

Deforestation, over-cultivation and rural growth have severely damaged native vegetation of woodlands along roadsides in the Longitudinal Range-Gorge Region of Yunnan Province. This study wasconducted to evaluate the effect of different reforestation practices, which consisted of natural restoration or planting with tree seedlings that varied in species composition, coverage and diversity,on damaged roadside woodlands. Three randomly selected 10 m x 10 m plots in each reforestation practice were investigated. The results showed that the species composition, plant cover and speciesdiversity of the planted communities varied with reforestation strategies and time since planting. A higher number of species, proportion of native species and woody plants, canopy cover and speciesdiversity were found in naturally restored plots and in 3 - 4 year old plots that were planted with native plants. In the early stages of reforestation, herbs dominated the plant community in most plots, andwoody plants became more important with time after reforestation. Preliminary results suggest that plant height can be used an auxiliary indicator of plant cover to assess ecosystem function status ofthe restoration project. Also, evenness may be easier to restore than species richness. Natural restoration or reforestation with native dominant plants is a good management strategy for vegetationrestoration or improvement