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Now showing items 129 - 144 of 152

  • Pulse width modulated buck-boost five-level current source inverters

    D. M. Vilathgamuwa   F. Blaabjerg   P. C. Loh   F. Gao  

    This paper presents new five-level current source inverters (CSIs) with voltage/current buck-boost capability. Being different from the existing multilevel CSI; the proposed CSIs were first designed to regulate the flowing path of dc input current by controlling two additional active switches; resulting in the natural balance of input current. For maintaining the normalized volt-sec average unchanged; the alternative phase opposition disposition (APOD) modulation scheme with typical gating signal mapping technique from voltage source inverter (VSI) to CSI can be assumed to control the five-level buck-boost CSIs. Next by observing the hidden current charging path during inductive charging interval under APOD modulation; it is noted that the buck-boost five-level CSI can then be further modified with lesser active component without degrading output performance. To verify the theoretical findings; Matlab simulations with PSIM coupler were performed before constructed laboratory prototypes were tested; whose captured results are presented for visual confirmation.
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  • Cochlear implantation using a custom guide catheter in 14 patients with incomplete partition type III

    H. Tian   L. Wang   F. Gao   W. Liang   K.A. Peng  

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  • Strain-controlled fatigue properties of Ti3Al based alloy : Cao, J., Sun, F., Cao, C. and Gao, Y. Xiyou Jinshu Cailiao yu Gongcheng (Rare Metal Materials and Engineering) (1996) 25, 17–20

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  • Effect of TiNi in dry sliding wear of laser melt deposited Ti2Ni/TiNi alloys

    F. Gao   H.M. Wang  

    Wear resistant TiNi-based intermetallic alloys reinforced by isolated irregular Ti 2Ni particles were fabricated by a laser melt deposition process. The alloy Ti50Ni50 included Ti 2Ni and B2 TiNi, while the alloy Ti53.8Ni46.2 consisted of Ti 2Ni and martensitic TiNi. Wear resistance of the alloys was evaluated on a block-on-wheel dry sliding wear tester at room temperature under loads of 98 N, 147 N and 196 N. The Ti 2Ni/TiNi intermetallic alloys exhibited high wear resistance. The intermetallic alloy Ti50Ni50 showed less plastic deformation than Ti53.8Ni46.2 owing to the pseudoelasticity of Ti50Ni50, while wear mass loss of Ti53.8Ni46.2 was slightly higher than Ti50Ni50 because Ti53.8Ni46.2 had more Ti 2Ni reinforcing phase that enhanced the Ti 2Ni/TiNi intermetallic alloys wear resistance at high contact stress. [All rights reserved Elsevier].
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  • Mapping daily evapotranspiration at field scales over rainfed and irrigated agricultural areas using remote sensing data fusion

    C. Cammalleri   M.C. Anderson   F. Gao   C.R. Hain   W.P. Kustas  

    Graphical abstract Highlights • A globally applicable ET MODIS/Lansat data fusion procedure was tested. • Differences in the performance on irrigated and rainfed fields were analyzed. • Accuracy of ET map is reduced when field size is smaller than MODIS pixel size. Abstract Continuous monitoring of daily evapotranspiration (ET) at field scale can be achieved by combining thermal infrared remote sensing data information from multiple satellite platforms, given that no single sensor currently exists today with the required spatiotemporal resolution. Here, an integrated approach to field-scale ET mapping is described, combining multi-scale surface energy balance evaluations and a data fusion methodology, namely the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), to optimally exploit spatiotemporal characteristics of image datasets collected by the Landsat and Moderate resolution Imaging Spectroradiometer (MODIS) sensors, as well as geostationary platforms. Performance of this methodology is evaluated over adjacent irrigated and rainfed fields, since mixed conditions are the most challenging for data fusion procedures, and in two different climatic regions: a semi-arid site in Bushland, TX and a temperate site in Mead, NE. Daytime-total ET estimates obtained for the Landsat overpass dates suggest that the intrinsic model accuracy is consistent across the different test sites (and on the order of 0.5 mmd −1 ) when contemporaneous Landsat imagery at 30-m resolution is available. Comparisons between tower observations and daily ET datastreams, reconstructed between overpasses by fusing Landsat and MODIS estimates, provide a means for assessing the strengths and limitations of the fused product. At the Mead site, the model performed similarly for both irrigated and rainfed fields, with an accuracy of about 0.9 mmd −1 . This similarity in performance is likely due to the relatively large size of the fields (≈50 ha), suggesting that the soil moisture dynamics of the irrigated fields are reasonably well captured at the 1-km MODIS thermal pixel scale. On the other hand, the accuracy of daily retrievals for irrigated fields at the Bushland site was lower than that for the rainfed field (errors of 1.5 and 1.0 mmd −1 , respectively), likely due to the inability of the model to capture ET spikes right after irrigation events for fields substantially smaller than MODIS data resolution. At this site, the irrigated fields were small (≈5 ha) compared to the MODIS pixel size, and sparsely distributed over the landscape, so sporadic contributions to ET from soil evaporation due to irrigation were not captured by the 1-km MODIS ET retrievals. However, due the semiarid environment at Bushland, these irrigation-induced spikes in soil evaporation are not long-lived and these underestimations generally affect the irrigation dates only and they do not seem to influence negatively the estimates at the seasonal scale. ET data fusion is expected to perform better over agricultural areas where irrigation is more spatially continuous, resulting in moisture fluxes that are more uniform at the MODIS pixel scale. Overall, the model accurately reproduces the ET temporal dynamics for all the experimental sites, and is able to capture the main differences that were observed between irrigated and rainfed fields at both daily and seasonal time scales.
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  • Isolation and characterization of a novel AP2/EREBP-type transcription factor OsAP211 inOryza sativa

    F. Gao   J. -M. Chen   A. -S. Xiong   R. -H. Peng   J. -G. Liu   B. Cai   Q. -H. Yao  

    AP2 (APETALA2)/EREBPs (ethylene responsive element binding proteins) are the primary members of a family of transcription factors and OsAP211 was isolated from Oryza sativa L using the yeast one-hybrid system. It can specifically bind to the promoter containing three tandem repeats of DRE core sequence: TACCGACAT and activate the transcription of the downstream lacZ gene in the yeast one-hybrid system. OsAP211 contained a single open reading frame of 225 amino acids and encoded a protein containing a conserved AP2/EREBP domain featuring the DREB family. The semi-quantitative RT-PCR (s-Q RT-PCR) analysis indicated OsAP211 was strongly induced by low temperatures but not by NaCl and drought. It accumulates primarily in shoot tips during the tillering stage and young spikes during the booting stage. OsAP211 might function as a DRE-binding transcription factor in stress signal transduction pathways in rice.
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  • 99/01782 Thermal reaction kinetics of coal series kaolinite: Gao, F. et al. Ranliao Huaxue Xuebao, 1998, 26, (2), 135–139. (In Chinese)

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  • Re: Non-invasive prenatal testing for trisomies 21, 18 and 13: clinical experience from 146958 pregnancies. H. Zhang, Y. Gao, F. Jiang, M. Fu, Y. Yuan, Y. Guo, Z. Zhu, M. Lin, Q. Liu, Z. Tian, H. Zhang, F. Chen, T. K. Lau, L. Zhao, X. Yi, Y. Yin and W. Wang. Ultrasound Obstet Gynecol 2015; 45: 530-538.

    Benn, P  

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  • Pharmacological characterization of α-MSH-derivatives

    W. Sihver   F. Gao   C. Jurischka   C. Haase-Kohn   J. Steinbach   D. Carta   C. Bolzati   A. Calderan   J. Pietzsch   H.J. Pietzsch  

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  • Virtual cell modelling and simulation software environment

    L.M. Loew   Y. Li   F. Gao   A. Lakshminarayana   F. Morgan   M.L. Blinov   B.M. Slepchenko   J.C. Schaff   I.I. Moraru  

    The Virtual Cell (VCell; http://vcell.org/) is a problem solving environment, built on a central database, for analysis, modelling and simulation of cell biological processes. VCell integrates a growing range of molecular mechanisms, including reaction kinetics, diffusion, flow, membrane transport, lateral membrane diffusion and electrophysiology, and can associate these with geometries derived from experimental microscope images. It has been developed and deployed as a web-based, distributed, client?server system, with more than a thousand world-wide users. VCell provides a separation of layers (core technologies and abstractions) representing biological models, physical mechanisms, geometry, mathematical models and numerical methods. This separation clarifies the impact of modelling decisions, assumptions and approximations. The result is a physically consistent, mathematically rigorous, spatial modelling and simulation framework. Users create biological models and VCell will automatically (i) generate the appropriate mathematical encoding for running a simulation and (ii) generate and compile the appropriate computer code. Both deterministic and stochastic algorithms are supported for describing and running non-spatial simulations; a full partial differential equation solver using the finite volume numerical algorithm is available for reaction?diffusion?advection simulations in complex cell geometries including 3D geometries derived from microscope images. Using the VCell database, models and model components can be reused and updated, as well as privately shared among collaborating groups, or published. Exchange of models with other tools is possible via import/export of SBML, CellML and MatLab formats. Furthermore, curation of models is facilitated by external database binding mechanisms for unique identification of components and by standardised annotations compliant with the MIRIAM standard. VCell is now open source, with its native model encoding language (VCML) being a public specification, which stands as the basis for a new generation of more customised, experiment-centric modelling tools using a new plug-in based platform.
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  • 231 Clinical pharmacodynamic assay development for the first in class investigational ubiquitin activating enzyme (UAE) inhibitor MLN7243

    B. Bahamón   F. Gao   B. Stringer   Y. Yang   J. Shi   K. Burke   J. Huck   T. Traore   D. Bowman   H. Danaee   M. Millhollen   M. Hyer   N. Bence   Y. Ishii  

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  • Gao Village: Rural Life in Modern Chinaby Mobo C. F. Gao

    Review by: Andrew Kipnis  

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  • Differentiation of pancreatic ductal adenocarcinoma from inflammatory mass: added value of magnetic resonance elastography

    Y. Liu   M. Wang   R. Ji   L. Cang   F. Gao   Y. Shi  

    Aim To examine whether incorporating magnetic resonance elastography (MRE) with contrast-enhanced computed tomography (CE-CT) or dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can provide a benefit in differentiating pancreatic ductal adenocarcinoma (PDAC) from inflammatory mass (IM). Materials and methods Thirty patients with IM and 56 patients with PDAC confirmed by histopathology were identified retrospectively via a prospectively maintained database. All patients underwent CE-CT or DCE-MRI together with dual-frequency MRE at 40 and 60 Hz. A five-point scale for likelihood of pancreatic malignancy was used by two experienced radiologists in consensus. Diagnostic accuracy of CE-CT/DCE-MRI, MRE, and their combination (modeled by logistic regression analysis) was estimated using receiver operating characteristic (ROC) analysis with a leave-one-out cross validation. Results Accuracies for determination of PDAC by 60-Hz MRE, 40-Hz MRE, CE-CT/DCE-MRI, and the combination of CE-CT or DCE-MRI and 60- and 40-Hz MRE, were 70.2%, 77.4%, 83.3%, 75%, and 92.9%, respectively. CE-CT or DCE-MRI combined with 40-Hz MRE significantly improved diagnostic performance versus CE-CT or DCE-MRI alone (area under the ROC curve [AUC]: 0.937 versus 0.783, p< 0.01) by increasing specificity (96.9% versus 62.1%, p= 0.002) without a significant loss of sensitivity (90.9% versus 94.6%, p =0.727), while combined CE-CT or DCE-MRI with 60-Hz MRE did not significantly change diagnostic performance versus CE-CT/DCE-MRI alone (AUC: 0.760 versus 0.783, p= 0.697). Conclusion Combined assessment by 40-Hz MRE with CE-CT/DCE-MRI may help to differentiate PDAC from IM in a relatively non-invasive fashion. Highlights • MRE is a feasible mode for differentiating the mechanical properties of pancreatic inflammatory masses and carcinomas. • Combined assessment with 40-Hz MRE and conventional contrast imaging significantly increased specificity for distinguishing pancreatic ductal adenocarcinomas from inflammatory masses when compared with conventional imaging alone. • MRE (40 Hz) can be recommended as a supplement to a routine clinical pancreatic imaging protocol.
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  • Nucleation of Cr precipitates in Fe–Cr alloy under irradiation

    Y.Y. Dai   L. Ao   Q.Q. Sun   L. Yang   J.L. Nie   S.M. Peng   X.G. Long   X.S. Zhou   X.T. Zu   L. Liu   X. Sun   D. Terentyev   F. Gao  

    Graphical abstract Highlights • MD and MMC methods are combined to study the nucleation of Cr precipitates. • The number of Frenkel pairs increases with increasing the overlapped cascades. • Cascade overlap could promote the formation of Cr precipitates in Fe–Cr alloys. • Cr, vacancy clusters in overlapped cascades enhance nucleation of Cr precipitates. Abstract The nucleation of Cr precipitates induced by overlapping of displacement cascades in Fe–Cr alloys has been investigated using the combination of molecular dynamics (MD) and Metropolis Monte Carlo (MMC) simulations. The results reveal that the number of Frenkel pairs increases with the increasing of overlapped cascades. Overlapping cascades could promote the formation of Cr precipitates in Fe–Cr alloys, as analyzed using short range order (SRO) parameters to quantify the degree of ordering and clustering of Cr atoms. In addition, the simulations using MMC approach show that the presence of small Cr clusters and vacancy clusters formed within cascade overlapped region enhance the nucleation of Cr precipitates, leading to the formation of large Cr dilute precipitates.
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  • Design and throughput analysis of an a backoff scheme for wireless LANs

    F. Li   B. Zhao   F. Gao   J. Fan  

    In order to improve the performance of IEEE 802.11 Distributed Coordination Function (DCF) scheme which is widely used for Ad Hoc networks and wireless LANs; a new adaptive minimum contention window binary exponential backoff algorithm (referred to as AWBEB algorithm) is proposed. Then we model the AWBEB algorithm scheme by bidimensional discrete-time Markov Chain; the transmission probability for a node and the stationary distribution probabilities of AWBEB algorithm are derived. The throughput and the saturation throughput of the proposed scheme are investigated by numerical analysis and simulation. The AWBEB algorithm operates closer to the theoretical limit quickly. The study results show that the system throughputs of AWBEB algorithm are better than that of DCF algorithm; and the results of AWBEB throughputs simulated by program agree with the calculation results preferably.
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  • Thermodynamic Calculation of Phase Equilibria and Its Applications in the Sn-Ag-Cu-Ni-Au System

    K. Ishida   X.J. Liu   C.P. Wang   F. Gao  

    Sn-Ag-Cu base solders are the most potential candidates to substitute of Sn-Pb eutectic solder. Gold (Au) coatings are used to protect conductor surface from oxidation and thereby to promote the solderability; and nickel (Ni) is often used as a diffusion barrier layer between lead-free solders and substrates to restrict the growing of intermetallic compound layers. And the gold and nickel also are added to the Pb-free solders to improve their performance. In the present work; the thermodynamic calculations of phase equilibria in the Sn-Ag-Cu-Ni-Au system were carried out using the CALPHAD method. Some examples of application are presented; and it is shown that the CALPHAD method is a good tool to design Pb-free solders and understand the interfacial reaction.
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