Interference in transport through double barriers in interacting quantum wires

We investigate interference effects of the backscattering current through a double-barrier structure in an interacting quantum wire attached to noninteracting leads. Depending on the interaction strength and the location of the barriers, the backscattering current exhibits different oscillation and scaling characteristics with the applied voltage in the strong and weak interaction cases. However, in both cases, the oscillation behaviors of the backscattering current are mainly determined by the quantum mechanical interference due to the existence of the double barriers.Comment: 6 pages, 3 fig

Enhancement of anammox performance in a novel non-woven fabric membrane bioreactor (nMBR)

© 2015 The Royal Society of Chemistry. To reduce operating costs and membrane fouling of conventional membrane bioreactors (cMBR), a novel MBR using a non-woven fabric membrane (nMBR) was constructed and the performance of the two MBRs was compared for anaerobic ammonium oxidation (anammox) cultivation. The results showed that the start-up period for the nMBR (44 days) was notably shorter than that for the cMBR (56 days), meanwhile the nMBR achieved a 2-times higher nitrogen removal rate (231.5 mg N per L per d) compared to the cMBR (112.3 mg N per L per d). Illumina MiSeq sequencing showed that Candidatus Kuenenia and Candidatus Jettenia were the main distinguished anammox bacteria. FISH analysis revealed that anammox bacteria predominated in both reactors, especially in the nMBR (58%) corresponding to a qPCR analysis of 1.07 × 109 copies per mL (day 120). N2O emission analysis confirmed the advantage of the nMBR in N2O reduction to reduce the influence of greenhouse gas emission while treating identical nitrogen. These results clearly demonstrated that nMBRs could be a prospective choice for anammox start-up and performance enhancement

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

A Direct Collocation method for optimization of EMG-driven wrist muscle musculoskeletal model

EMG-driven musculoskeletal model has been broadly used to detect human intention in rehabilitation robots. This approach computes muscle-tendon force and translates it to the joint kinematics. However, the muscle-tendon parameters of the musculoskeletal model are difficult to measure in vivo and varied across subjects. In this study, a direct collocation (DC) method is proposed to optimize the subject-specific parameters in a wrist musculoskeletal model. The resultant optimized parameters are used to estimate the wrist flexion/extension motion. The estimation performance is compared with the parameters optimized by the genetic algorithm. Experiment results show that the DC methods have a similar performance compared with GA, in which the mean correlation are 0.96 and 0.93 for the genetic algorithm and DC method respectively. But the direction collocation method requires less optimization time

Bearing-Only Formation Control With Prespecified Convergence Time

This article considers the bearing-only formation control problem, where the control of each agent only relies on relative bearings of their neighbors. A new control law is proposed to achieve target formations in finite time. Different from the existing results, the control law is based on a time-varying scaling gain. Hence, the convergence time can be arbitrarily chosen by users, and the derivative of the control input is continuous. Furthermore, sufficient conditions are given to guarantee almost global convergence and interagent collision avoidance. Then, a leader-follower control structure is proposed to achieve global convergence. By exploring the properties of the bearing Laplacian matrix, the collision avoidance and smooth control input are preserved. A multirobot hardware platform is designed to validate the theoretical results. Both simulation and experimental results demonstrate the effectiveness of our design

Simulation of multilevel cell spin transfer switching in a full-Heusler alloy spin-valve nanopillar

Author name used in this publication: Shi, S. Q.2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

An EMG-driven musculoskeletal model for estimating continuous wrist motion

EMG-based continuous wrist joint motion estimation has been identified as a promising technique with huge potential in assistive robots. Conventional data-driven model-free methods tend to establish the relationship between the EMG signal and wrist motion using machine learning or deep learning techniques, but cannot interpret the functional relationship between neuro-commands and relevant joint motion. In this paper, an EMG-driven musculoskeletal model is proposed to estimate continuous wrist joint motion. This model interprets the muscle activation levels from EMG signals. A muscle-tendon model is developed to compute the muscle force during the voluntary flexion/extension movement, and a joint kinematic model is established to estimate the continuous wrist motion. To optimize the subject-specific physiological parameters, a genetic algorithm is designed to minimize the differences of joint motion prediction from the musculoskeletal model and joint motion measurement using motion data during training. Results show that mean root-mean-square-errors are 10.08°, 10.33°, 13.22° and 17.59° for single flexion/extension, continuous cycle and random motion trials, respectively. The mean coefficient of determination is over 0.9 for all the motion trials. The proposed EMG-driven model provides an accurate tracking performance based on user’s intention

CCA-based Spatio-temporal Filtering for Enhancing SSVEP Detection

Brain-computer interface (BCI) can provide a direct communication path between the human brain and an external device. The steady-state visual evoked potential (SSVEP)-based BCI has been widely explored in the past decades due to its high signal-to-noise ratio and fast communication rate. Several spatial filtering methods have been developed for frequency detection. However the temporal knowledge contained in the SSVEP signal is not effectively utilized. In this study, we propose a canonical correlation analysis (CCA)-based spatio-temporal filtering method to improve target classification. The training signal and two types of template signals (i.e. individual template and artificial sine-cosine reference) are first augmented via temporal information. Three sets of augmented data are then concatenated by trials. The CCA is performed twice, between the newly obtained training data and each template. The trained four spatial filters can be applied in the following test process. A public benchmark dataset was used to evaluate the performance of the proposed method and the other three comparing methods, such as CCA, MsetCCA, and TRCA. The experimental results indicate that the proposed method yields significantly higher performance. This paper also explored the effects of the number of electrodes and training blocks on classification accuracy. The results further demonstrated the effectiveness of the proposed method in SSVEP detection

GREB1 (growth regulation by estrogen in breast cancer 1)

Review on GREB1 (growth regulation by estrogen in breast cancer 1), with data on DNA, on the protein encoded, and where the gene is implicated

Comparison of sterols and fatty acids in two species of Ganoderma

<p>Abstract</p> <p>Background</p> <p>Two species of <it>Ganoderma, G. sinense </it>and <it>G. lucidum</it>, are used as <it>Lingzhi </it>in China. Howerver, the content of triterpenoids and polysaccharides, main actives compounds, are significant different, though the extracts of both <it>G. lucidum </it>and <it>G. sinense </it>have antitumoral proliferation effect. It is suspected that other compounds contribute to their antitumoral activity. Sterols and fatty acids have obvious bioactivity. Therefore, determination and comparison of sterols and fatty acids is helpful to elucidate the active components of <it>Lingzhi</it>.</p> <p>Results</p> <p>Ergosterol, a specific component of fungal cell membrane, was rich in <it>G. lucidum </it>and <it>G. sinense</it>. But its content in <it>G. lucidum </it>(median content 705.0 μg·g^-1, range 189.1-1453.3 μg·g^-1, n = 19) was much higher than that in <it>G. sinense </it>(median content 80.1 μg·g^-1, range 16.0-409.8 μg·g^-1, n = 13). Hierarchical clustering analysis based on the content of ergosterol showed that 32 tested samples of <it>Ganoderma </it>were grouped into two main clusters, <it>G. lucidum </it>and <it>G. sinense</it>. Hierarchical clustering analysis based on the contents of ten fatty acids showed that two species of <it>Ganoderma </it>had no significant difference though two groups were also obtained. The similarity of two species of <it>Ganoderma </it>in fatty acids may be related to their antitumoral proliferation effect.</p> <p>Conclusions</p> <p>The content of ergosterol is much higher in <it>G. lucidum </it>than in <it>G. sinense</it>. Palmitic acid, linoleic acid, oleic acid, stearic acid are main fatty acids in <it>Ganoderma </it>and their content had no significant difference between <it>G. lucidum </it>and <it>G. sinense</it>, which may contribute to their antitumoral proliferation effect.</p