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41.
This paper presents a new fully differential CMOS class AB transmitter for 10 Gb/s serial links. The transmitter consists of a fully differential multiplexer, a rail-to-rail configured pre-amplification stage, and a push-pull output stage. The multiplexer achieves a high multiplexing speed by using modified pseudo-NMOS logic where pull-up networks are replaced with self-biased active inductors. The rail-to-rail configured pre-amplification stage with active inductors amplifies the signals from the multiplexer. The fully differential output current is generated by a class AB output stage operated in a push-pull mode. High data rates of the transmitter are obtained by ensuring that the transistors in both the pre-amplification and output stages are always in saturation and the voltage swing of all critical nodes is small. The fully differential configuration of the transmitter effectively suppresses common-mode disturbances, particularly those coupled from the power and ground rails, the electro-magnetic interference exerted from channels to neighboring devices is also minimized. The transmitter minimizes switching noise by drawing a constant current from the supply voltage. The transmitter has been implemented in TSMC 0.18 μm 1.8 V 6-metal CMOS technology and analyzed using Spectre from Cadence Design Systems with BSIM3.3 device models. Simulation results demonstrate that the transmitter provides a 5 mA peak-to-peak differential output current with 100 ps eye-width and >5 mA eye-height at 10 Gb/s. The transmitter consumes 18 mW with a total transistor area of 100 μm2 approximately. Jean Jiang received the B.Eng. degree in Electrical Engineering from Wuhan University of Technology, Wuhan, China in 1995, and the M.A.Sc. degree in Electrical and Computer Engineering from Ryerson University, Toronto, Ontario, Canada in 2004. From 1999 to 2001, she worked for Ericsson Global IT Services where she was a technical staff to maintain computer networks. From 2002 to 2004, she was a research assistant and a M.A.Sc. student with the Microsystem Research Laboratory in the Department of Electrical and Computer Engineering at Ryerson University. She is now with Intel Corp., CA. as an IC design engineer. Her research interests are in analog CMOS circuit design for high-speed data communications. Jean Jiang was awarded the Ontario Graduate Scholarship in 2003–2005 for academic excellence. Fei Yuan received the B.Eng. degree in electrical engineering from Shandong University, Jinan, China in 1985, the M.A.Sc. degree in chemical engineering and Ph.D. degree in electrical engineering from University of Waterloo, Waterloo, Ontario, Canada in 1995 and 1999, respectively. During 1985–1989, he was a Lecturer in the Department of Electrical Engineering, Changzhou Institute of Technology, Jiangsu, China. In 1989 he was a Visiting Professor at Humber College of Applied Arts and Technology, Toronto, Ontario, Canada, and Lambton College of Applied Arts and Technology, Sarnia, Ontario, Canada. He was with Paton Controls Limited, Sarnia, Ontario, Canada as a Controls Engineer during 1989–1994. Since 1999 he has been with the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada, where he is currently an Associate Professor and the Associate Chair for Undergraduate Studies and Faculty Affairs. He is the co-author of the book Computer Methods for Analysis of Mixed-Mode Switching Circuits (Springer-Verlag, 2004, with Ajoy Opal). Dr. Yuan received the Ryerson Research Chair award from Ryerson University in Jan. 2005, the Research Excellence Award from the Faculty of Engineering and Applied Science of Ryerson University in 2004, the post-graduate scholarship from Natural Science and Engineering Research Council of Canada during 1997–1998, and the Teaching Excellence Award from Changzhou Institute of Technology in 1988. Dr. Yuan is a senior member of IEEE and a registered professional engineer in the province of Ontario, Canada.  相似文献   
42.
The interfacial electronic structure between oxide thin films and organic semiconductors remains a key parameter for optimum functionality and performance of next‐generation organic/hybrid electronics. By tailoring defect concentrations in transparent conductive ZnO films, we demonstrate the importance of controlling the electron transfer barrier at the interface with organic acceptor molecules such as C60. A combination of electron spectroscopy, density functional theory computations, and device characterization is used to determine band alignment and electron injection barriers. Extensive experimental and first principles calculations reveal the controllable formation of hybridized interface states and charge transfer between shallow donor defects in the oxide layer and the molecular adsorbate. Importantly, it is shown that removal of shallow donor intragap states causes a larger barrier for electron injection. Thus, hybrid interface states constitute an important gateway for nearly barrier‐free charge carrier injection. These findings open new avenues to understand and tailor interfaces between organic semiconductors and transparent oxides, of critical importance for novel optoelectronic devices and applications in energy‐conversion and sensor technologies.  相似文献   
43.
Molybdenum trioxide (MoO3) suffers from poor conductivity, a low rate capability, and unsatisfactory cycling stability in lithium‐ion batteries. The aliovalent ion doping may present an effective way to improve the electrochemical performances of MoO3. Here, it is shown, by first‐principle calculations, that doping MoO3 with V by 12.5% can modulate significantly electronic structure and provide a small diffusion barrier for enhancing the electrochemical performance of MoO3. The ultralong Mo0.88V0.12O2.94 nanostructures, which retain the h‐MoO3 structure and present an exceptionally high conductivity and fast ionic diffusion due to the substitution of V, facilitating lithiation/delithiation behavior, and induce a fine nanosized structure with a reduced volume change are prepared. As a result, the stress and strain are alleviated during the Li‐ion intercalation/deintercalation processes, improving the cycling stability and rate capability. Such a large improvement in the electrochemical properties can be ascribed to the stabilizing effect of V, the small migration energy barrier, and short diffusion path, which arise from the introduction of V into MoO3. The unique engineering strategy and facile synthesis route open up a new avenue in modifying and developing other species of electrode materials.  相似文献   
44.
Herein, the novel concept of a solid‐state electrode materials with ionic‐liquid (IL) properties is presented. These composite materials are a mixture of electroactive matter, an electronic conductor, a solid‐state ionic conductor and a polymeric binder. The approach of a solid‐state ionic conductor combines the high safety of an IL with the nanoconfinement of such a liquid in a mesoporous silica framework, an ionogel, thus leading to a solid with liquid‐like ionic properties. The same ionic conductor is also used as a solid‐state separator to evaluate the properties of our solid‐state electrode materials in all‐solid‐state batteries. Such a concept of a solid‐state electrode material contributes to addressing the challenge of energy storage, which is one of the major challenges of the 21st century. The ionogel, along with its processability, allows a single‐step preparation of the assembly of the solid‐state electrode and solid‐electrolyte separator and can be applied without specific adaptation to present, thick electrodes prepared by the widespread tape‐casting technique. The filling of the electrode porosity by an ionogel is shown by elemental mapping using scanning electron microscopy, and is subsequently confirmed by electrochemical measurements. The ionogel approach is successfully applied without specific adaptation to two state‐of‐the‐art, positive electroactive materials developed for future‐generation lithium‐ion batteries, namely LiFePO4 and LiNi1/3Mn1/3Co1/3O2.  相似文献   
45.
一种快速分层递阶DSmT近似推理融合方法(A)   总被引:6,自引:1,他引:6       下载免费PDF全文
 本文提出了一种分层递阶的DSmT快速近似推理融合方法,该方法针对超幂集空间中仅单子焦元具有信度赋值的情况,利用二叉树或三叉树分组技术对其刚性分组,与此同时,对每个信息源对应的各个分组焦元进行信度赋值求和,以便实现细粒度超幂集空间向粗粒度超幂集空间映射.然后运用DSmT组合规则和比例冲突分配规则对粗化超幂集空间的两个信息源进行融合,保存该融合结果作为父子之间节点连接权值,然后对每个分组焦元信度赋值归一化处理,通过设定树的深度,来确定分层递阶的次数.最后通过从多个角度比较新、老方法,从而充分地验证了新方法的优越性.  相似文献   
46.
We present RERBEE (robust efficient registration via bifurcations and elongated elements), a novel feature-based registration algorithm able to correct local deformations in high-resolution ultra-wide field-of-view (UWFV) fluorescein angiogram (FA) sequences of the retina. The algorithm is able to cope with peripheral blurring, severe occlusions, presence of retinal pathologies and the change of image content due to the perfusion of the fluorescein dye in time. We have used the computational power of a graphics processor to increase the performance of the most computationally expensive parts of the algorithm by a factor of over × 1300, enabling the algorithm to register a pair of 3900 × 3072 UWFV FA images in 5-10 min instead of the 5-7 h required using only the CPU. We demonstrate accurate results on real data with 267 image pairs from a total of 277 (96.4%) graded as correctly registered by a clinician and 10 (3.6%) graded as correctly registered with minor errors but usable for clinical purposes. Quantitative comparison with state-of-the-art intensity-based and feature-based registration methods using synthetic data is also reported. We also show some potential usage of a correctly aligned sequence for vein/artery discrimination and automatic lesion detection.  相似文献   
47.
This paper reports on an analytical study of the performances of the ATM‐ABR service category in transporting TCP/IP flows over an ATM network. We explore the behavior of a TCP connection over an ATM‐ABR VC, in presence of exogenous non‐controlled traffic. This fluid analysis of the system allows the study of the interaction between the window‐based end‐to‐end flow control TCP protocol and the rate‐based flow control ABR mechanism, which is restricted to the ATM part of the network. The main aim of this study is to give performance evaluation formulae to model the behavior of such a TCP over ABR connection. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
48.
Domain switching pathways fundamentally control performance in ferroelectric thin film devices. In epitaxial bismuth ferrite (BiFeO3) films, the domain morphology is known to influence the multiferroic orders. While both striped and mosaic domains have been observed, the origins of the latter have remained unclear. Here, it is shown that domain morphology is defined by the strain profile across the film–substrate interface. In samples with mosaic domains, X‐ray diffraction analysis reveals strong strain gradients, while geometric phase analysis using scanning transmission electron microscopy finds that within 5 nm of the film–substrate interface, the out‐of‐plane strain shows an anomalous dip while the in‐plane strain is constant. Conversely, if uniform strain is maintained across the interface with zero strain gradient, striped domains are formed. Critically, an ex situ thermal treatment, which eliminates the interfacial strain gradient, converts the domains from mosaic to striped. The antiferromagnetic state of the BiFeO3 is also influenced by the domain structure, whereby the mosaic domains disrupt the long‐range spin cycloid. This work demonstrates that atomic scale tuning of interfacial strain gradients is a powerful route to manipulate the global multiferroic orders in epitaxial films.  相似文献   
49.
The coupling of the changes in bacterial quantitative and metabolic aspects during Microcystis aeruginosa bloom conditions together with several environmental parameters was studied in the hypereutrophic Villerest reservoir, France. Bacterial abundance varied from 5.20 to 21.28 × 106 bacteria-mL?1, while bacterial biomass ranged between 75 and 507 μg C mL?1. These results confirmed the highly eutrophic status of the Villerest reservoir. The relative quantitative importance of attached bacteria increased as Microcystis proliferated. Methyl-3H incorporation and D-(U-14C) glucose uptake varied from 8.99 to 60.57 × 106 cells-mL?1, and 0.016 to 1.587 μg CL?1 h?1, respectively. Correlations between several abiotic and biotic parameters showed that phytoplankton regulated bacterial growth by releasing organic carbon which is directly uptaken by heterotrophic bacteria. In the hypolimnion, the sedimentation of decaying algae represented a substantial substrate for bacterial growth.  相似文献   
50.
Model-based application development aims at increasing the application’s integrity by using models employed in clearly defined transformation steps leading to correct-by-construction artifacts. In this paper, we introduce a novel model-based approach for constructing correct distributed implementation of component-based models constrained by priorities. We argue that model-based methods are especially of interest in the context of distributed embedded systems due to their inherent complexity (e.g., caused by non-deterministic nature of distributed systems). Our method is designed based on three phases of transformation. The input is a model specified in terms of a set of behavioral components that interact through a set of high-level synchronization primitives (e.g., rendezvous and broadcasts) and priority rules for scheduling purposes. The first phase transforms the input model into a model that has no priorities. Then, the second phase transforms the deprioritized model into another model that resolves distributed conflicts by incorporating a solution to the committee coordination problem. Finally, the third phase generates distributed code using asynchronous point-to-point message passing primitives (e.g., TCP sockets). All transformations preserve the properties of their input model by ensuring observational equivalence. All the transformations are implemented and our experiments validate their effectiveness.  相似文献   
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