Band structures and transport properties of zigzag graphene nanoribbons with antidot arrays

We study the band and transport features of zigzag graphene nanoribbon with an antidot lattice. It is found that an antidot lattice could turn semi-metal graphene into a semiconductor. The size of the band gap can be tuned by the position of the antidots and the distance D between the two nearest antidots. For a finite superlattice with N antidots and a large D, a group of (N - 1) splitting resonant peaks and transmission-blockade regions appear alternately in the conductance spectrum. This indicates the formation of minibands and minigaps. In addition, Fano resonances can be observed when the antidots are localized near one edge of the nanoribbon. These features provide potential applications for graphene-based electronic and optoelectronic devices. © 2010 IOP Publishing Ltd.postprin

Fuzzy EMG classification for prosthesis control

This paper proposes a fuzzy approach to classify single-site electromyograph (EMG) signals for multifunctional prosthesis control. While the classification problem is the focus of this paper, the ultimate goal is to improve myoelectric system control performance, and classification is an essential step in the control. Time segmented features are fed to a fuzzy system for training and classification. In order to obtain acceptable training speed and realistic fuzzy system structure, these features are clustered without supervision using the Basic Isodata algorithm at the beginning of the training phase, and the clustering results are used in initializing the fuzzy system parameters. Afterwards, fuzzy rules in the system are trained with the back-propagation algorithm. The fuzzy approach was compared with an artificial neural network (ANN) method on four subjects, and very similar classification results were obtained. It is superior to the latter in at least three points: slightly higher recognition rate; insensitivity to overtraining; and consistent outputs demonstrating higher reliability. Some potential advantages of the fuzzy approach over the ANN approach are also discussed.published_or_final_versio

Management of Extracranial Carotid Artery Aneurysms:17 Years» Experience

AbstractObjectives:a retrospective review of seventeen-year (1980–1996) experience of the management of extracranial carotid artery aneurysms.Patients and methods:sixty-six aneurysms of extracranial carotid artery were seen in 63 patients. The diagnosis was confirmed by angiography in 51 patients and duplex ultrasonography in twelve. Twenty-eight (42%) patients had an atherosclerotic aneurysm, twenty-two (33%) had false aneurysms secondary to trauma, nine were congenital and seven were mycotic. All underwent aneurysm resection with saphenous-vein-graft interposition as the most common means of reconstruction.Results:one death occurred due to septicaemia in a diabetic patient with a mycotic aneurysm, giving an operative mortality of 1.5%. One patient had an immediate hemiparesis after carotid artery ligation, and three had a hemiparesis within 48 hours of operation (6.1%). After a change in technique to avoid a residual carotid stump, no further neurological problems were encountered in the following 28 patients.Conclusion:extracranial carotid aneurysms may be successfully managed with resection and reconstruction with autogenous saphenous vein. End-to-side anastomosis avoids a blind-ending stump which may be the source of emboli

Geochemical Constrains on Nature of Source Region of The Late Permian Emeishan Continental Flood Basalts, SW China

Abstract in http://www.lpi.usra.edu/meetings/gold2001/pdf/3488.pd

Reducing Health Risks from Indoor Exposures in Rapidly Developing Urban China.

Background: Over the past two decades there has been a large migration of China’s population from rural to urban regions. At the same time, residences in cities have changed in character from single-story or low-rise buildings to high-rise structures constructed and furnished with many synthetic materials. As a consequence, indoor exposures (to pollutants with outdoor and indoor sources) have changed significantly. Objectives: We briefly discuss the inferred impact that urbanization and modernization have had on indoor exposures and public health in China. We argue that growing adverse health costs associated with these changes are not inevitable, and we present steps that could be taken to reduce indoor exposures to harmful pollutants. Discussion: As documented by China’s Ministry of Health, there have been significant increases in morbidity and mortality among urban residents over the past 20 years. Evidence suggests that the population’s exposure to air pollutants has contributed to increases in lung cancer, cardiovascular disease, pulmonary disease, and birth defects. Whether a pollutant has an outdoor or an indoor source, most exposure to the pollutant occurs indoors. Going forward, indoor exposures can be reduced by limiting the ingress of outdoor pollutants (while providing adequate ventilation with clean air), minimizing indoor sources of pollutants, updating government policies related to indoor pollution, and addressing indoor air quality during a building’s initial design. Conclusions: Taking the suggested steps could lead to significant reductions in morbidity and mortality, greatly reducing the societal costs associated with pollutant derived ill health

Microwave assisted heterogeneous catalysis: effects of varying oxygen concentrations on the oxidative coupling of methane

The oxidative coupling of methane was investigated over alumina supported La2O3/CeO2 catalysts under microwave dielectric heating conditions at different oxygen concentrations. It was observed that, at a given temperature using microwave heating, selectivities for both ethane and ethylene were notably higher when oxygen was absent than that in oxygen/methane mixtures. The differences were attributed to the localised heating of microwave radiation resulting in temperature inhomogeneity in the catalyst bed. A simplified model was used to estimate the temperature inhomogeneity; the temperature at the centre of the catalyst bed was 85 °C greater than that at the periphery when the catalyst was heated by microwaves in a gas mixture with an oxygen concentration of 12.5% (v/v), and the temperature difference was estimated to be 168 °C in the absence of oxygen

Expression Analysis and Interaction Protein Screening of CRY1 in Strawberry

Cryptochrome 1 (CRY1), a main blue light receptor protein, plays a significant role in several biological processes. However, the expression patterns and function of CRY1 in strawberry have not been identified. Here, the expression profile of CRY1 in different tissues and developmental stages of strawberry fruit, and expression patterns response to abiotic stresses (low temperature, salt and drought) were analyzed. Its subcellular localization, interaction proteins and heterologous overexpression in tobacco were also investigated. The results showed that CRY1 was mainly expressed in leaves and fruits with an expression peak at the initial red stage in strawberry fruit. Abiotic stresses could significantly induce the expression of CRY1. The CRY1 protein was located in both nucleus and cytoplasm. Five proteins (CSN5a-like, JAZ5, eIF3G. NF-YC9, and NDUFB9) interacting with CRY1 were discovered. Genes related flowering times, such as HY5 and CO, in three overexpressed FaCRY1 tobacco lines, were significantly upregulated. Taken together, our results suggested CRY1 have a broad role in biological processes in strawberry

An Assessment Of Traditional Uighur Medicine In Current Xinjiang Region (China)

Background: The main objectives of this study were to assess the current research and development of traditional Uighur medicine in Xinjiang (China), and to evaluate the promising pharmacological products of traditional Uighur medicine for further studies.Materials and Methods: Traditional Uighur medicine data of medicine registry, patent, and academic publications was collected and analyzed.Results: Data showed that, among the registered and studied traditional Uighur medicine, the main therapeutic areas of traditional Uighur medicine focused on skin disease, urogenital disease, rheumatism and digestive system disease. The representative traditional Uighur patent medicine included the following: BaixuanXiatare Tablets, Kaliziran Tincture and Vernoniaanthelmintica Injection (Psoriasis and vitiligo); Xi-payimazibiziLiquid (prostatitis); KursiKaknaq (urinary tract infection); Tongzhisurunjiang Capsules (anti-rheumatism medicine); HuganBuzure Granules (digestive system disease). Moreover, ten Uighur herbs were widely used, including: ResinaScammoniae, Folium FumicisDentati, HerbaDracocephali, Semen AmygdaliDulcis, HerbaChamomillae, FructusPimpinellaeanisi, Cortex Foeniculi, FructusVernoniae, FructusApii, and Radix AnacycliPyrethri.Conclusion: This study concluded by indicating that traditional Uighur medicine with excellent curative effect should be screened in details for their phytochemical properties and pharmacological activity to discover new bioactive constituents.Key words: Traditional Uighur medicine, Traditional Uighur patent medicine, Uighur her

Performance analysis of finned-tube CO2 gas cooler with advanced 1D-3D CFD modelling development and simulation

Research data for this article: Data not available / Data will be made available on request.Supplementary material is available online at: https://www.sciencedirect.com/science/article/pii/S1359431120307122?via%3Dihub#s0070 .Due to natural refrigerant applied, CO2 transcritical refrigeration and heat pump systems have been widely applied and attracted more attentions. As a main component, CO2 gas cooler plays an important role in the system performance and thus requires further development for design and control optimizations with advanced technology. Correspondingly, a new coupled 1D and 3D Computational Fluid Dynamics (CFD) model on a finned-tube CO2 gas cooler has been proposed and developed. The CFD model has been validated by comparing with literatures for parameters including airside heat transfer coefficient, refrigerant side temperature profile as well as heating capacity. The model has been applied to predict the heat exchanger performance at different operating conditions of both air and refrigerant sides and maldistributions of air flow inlet. It is found from the simulation results that the refrigerant temperature decreases abruptly in the first coil row and the refrigerant temperature profile along the heat exchanger tubes is affected by thermal conduction between two adjacent tube rows through fins. In addition, the higher air flow inlet velocity can reduce greatly the coil approach temperature and thus improve the system efficiency. Similar effect can also be found from refrigerant pressure. Furthermore, the non-uniform air flow patterns can affect considerably the coil performance in terms of the refrigerant temperature profile, coil approach temperature, coil heating capacity and system energy efficiency. The developed CFD model can be an efficient tool for the performance evaluation and optimisation of the CO2 gas cooler and its associated system.The authors would like to acknowledge the support received from Research Councils UK (ESPRC, EP/R000298/1) for this research project