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Effect of quercetin on chronic enhancement of spatial learning and memory of mice

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Science china(Life Sciences) 2006年第6期49卷 583-590页

作者： LIU Jiancai1,YU Huqing2 & NING Xinbao1 1. State Key Laboratory of Modern Acoustics,department of Electronics Science and engineering,institute of Biological Medical Electronic engineering,nanjing University,nanjing 210093,china 2. department of Biology Science and technology,nanjing University,nanjing 210093,china State Key Laboratory of Modern Acoustics Department of Electronics Science and Engineering Institute of Biological Medical Electronic Engineering Nanjing University Nanjing 210093 China department of Biology Science and technology Nanjing University Nanjing 210093 China

In this study we evaluated the effect of quercetin on D-galactose-induced aged mice using the Morris water maze (MWM) test. Based on the free radical theory of aging, experiments were performed to study the possible biochemical mechanisms of glutathione (GSH) level; hydroxyl radical (OH ) in the hippocampus; cerebral cortex; the brain tissue enzyme activity of the mice. The results indicated that quercetin can enhance the exploratory behavior, spatial learning; memory of the mice. The effects relate with enhancing the brain functions; inhibiting oxidative stress by quercetin,; relate with increasing the GSH level; decreasing the OH content. These findings suggest that quercetin can work as a possible natural anti-aging pharmaceutical product.

关键词： quercetin aging learning memory free radical reactive oxygen species (ROS) glutathione (GSH)

Cooperative Spectrum Sensing in Cognitive Radio Using Bayesian Updating with Multiple Observations

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Journal of Electronic Science and technology 2019年第3期17卷 252-259页

作者： Yung-Fa Huang Jyu-Wei Wang the department of Information and communication engineering Chaoyang University of TechnologyTaichung 41368 the department of Photonics and communication engineering Asia UniversityTaichung 41354

We study cooperative spectrum sensing in cognitive radio (CR) networks using the hidden Markov model (HMM) for opportunistic spectrum access (OSA). We assume that the primary channel operates in a time division multiple address (TDMA) manner. Thus, spectrum sensing is operating in a slot-by-slot basis. In contrast to the conventional Bayesian updating using only one observation, in this work, we propose to perform the update in a concatenated fashion with all the observations available from the secondary users (SUs). In the proposed scheme, a predefined threshold on the belief is used for determining the channel activity. With the threshold, the proposed scheme is more flexible in the system operation than the simple majority vote scheme, in which no such threshold is available. We compare, by simulations, the performance of the proposed concatenated update scheme with that of the majority vote scheme and show that the probabilities of correctly detecting a busy state and an idle state are about 1 as the number of SUs is as large as 15, so the effects of the further increase in the number of SUs are limited.

关键词： Bayesian updating cognitive radio(CR) cooperative sensing hidden Markov model(HMM)

High Temperature Deformation of Al_2O_3/Cu Composites

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Journal of Materials Science & technology 2001年第3期17卷 325-328页

作者： Jianjun WU. Yun ZHANG, Yanfei JIANG and Meiyun XUE department of Material Science and engineering, Hebei University of technology, Tianjin 300130, china Tingquan LEI School of Materials Science and engineering, Harbin institute of technology, Uarbin 15000 Hebei Univ Technol Dept Mat Sci & Engn Tianjin 300130 Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150006 Peoples R China

This work concerns with the high temperature deformation of internally oxidized Al2O3/Cu composites. The investigation revealed that dispersive alumina can obstruct dislocation sliding and define the subgrain size thereby improve significantly the strength of the materials at high temperature. The sliding of dislocations is a main deformation mechanism in the given temperature range. The sliding of grain boundary and diffusive creep play important roles at high temperature and low strain rate. The dispersoids can raise the recrystallization temperature to higher than 1223 K. Dynamic recovery is a main softening way under the experimental conditions. Higher deformation rate and lower deformation temperature imply a higher flow stress.

关键词： High Temperature Deformation of Al2O3/Cu Composites Cu Al

RESEARCH ON BEHAVIORS OF ELECTRORHEOLOGICAL FLUID-BASED SEMIACTIVE ROBOT FINGERTIPS

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Chinese Journal of Mechanical engineering 1998年第2期11卷 17-22,29页

作者： Yue Hong Li Tiejun department of Mechanical engineering, Hebei University of technology Peng Yuqing Cai Hegao Hebei University of technology Harbin institute of technology Hebei Univ of technology China

A new design of robot gripper with electrorheological fluid (ERF) semiactive tips is described. There are two remarkable properties using this fingertip. One is the higher lifting capability at little grasp force, which can realize stable grasp. Another is the damping controllable which can be used for controlling contact forces. A viscoelastic plastic model for normal direction of the fingertip is proposed to explore the contact behavior. The electric field strength is induced into the dynamic model of contact transition for simulations. The simulation results and conclusions are given.

关键词： Robot Semiactive fingertip Electrorheological fluid Dynamic model Simulation

Synthesis of benzoxazine-based phenolic resin containing furan groups

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Chinese Chemical Letters 2010年第7期21卷 868-871页

作者： Sheng Fang Li School of Chemical and Material engineering,Huangshi institute of technology,Huangshi 435003,china [a] School of Chemical Material engineering Huangshi Institute of Technology Huangshi 435003 China

A novel benzoxazine-based phenolic resin containing furan groups（PFB） was synthesized via simple two-step reactions and the structure of PFB was confirmed by FTIR and ~1H NMR *** scanning calorimetry（DSC） showed that the polybenzoxazine cured from PFB had good heat resistance and lower polymerization temperature compared with that of benzoxazine-based phenolic resins.

关键词： Benzoxazine Phenolic resin Furan Phenol-furfural Performance enhancement

WATER TUNNEL EXPERIMENTAL INVESTIGATION ON THE DRAG REDUCTION CHARACTERISTICS OF THE TRAVELING WAVY WALL

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Journal of Hydrodynamics 2011年第1期23卷 65-70页

作者： YAO Yan LU Chuan-jing SI Ting ZHU Kun department of engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China Beijing Electromechanic engineering institute Beijing 100074 China State Key Laboratory of Ocean engineering Shanghai Jiao Tong University Shanghai 200030 China department of modem Mechanics University of Science and Technology of China Hefei 230027 China

Drag reduction experiment of the traveling wavy wall at high Reynolds number is conducted.A suit of traveling wavy wall device is *** drag forces of the traveling wavy wall with various wave speeds（c）are measured under different water speeds（U）in the K15 cavitation water tunnel and are compared with that of the flat *** results show that the mean drag force of the traveling wavy wall have decreased and then increased with oscillation frequency increasing at the same flow *** different flow speeds,when traveling wave wall reached to the minimum of drag force,the corresponding the ratio of the wall motion phase speed c to flow speed U,c /U is slightly *** the parameters of the experiment,whenc /U reaches a certain value,the drag force of the traveling wavy wall can be less than that of the flat *** drag reduction can be up to 42%.Furthermore,as the value ofc /U increases,the traveling wavy wall can restrain the separation and improve the quality of flow field.

关键词： flow control drag reduction traveling wavy wall water tunnel test

Second-order consensus in networks of dynamic agents with communication time-delays

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Journal of Systems engineering and Electronics 2010年第1期21卷 88-94页

作者： Bo Yang1,2, Huajing Fang3, and Hua Wang4 1. School of Navigation, Wuhan University of technology, Wuhan 430063, P. R. china 2. Wuhan Second Ship Design and Research institute, Wuhan 430064, P. R. china 3. department of Control Science and engineering, Huazhong University of Science and technology, Wuhan 430074, P. R. china 4. department of Aerospace and Mechanical engineering, Boston University, Boston MA02215, USA School of Navigation Wuhan University of Technology Wuhan 430063 P. R. China Wuhan Second Ship Design and Research institute Wuhan 430064 E R. China department of Control Science and engineering Huazhong University of Science and Technology Wuhan 430074 P. R. China department of Aerospace and Mechanical engineering Boston University Boston MA02215 USA

This paper proposes second-order consensus protocols with time-delays and gives the measure of the robustness of the protocols to the time-delay existing in the network of agents with second-order dynamics. By employing a frequency domain method, it is proven that the information states and their time derivatives of all the agents in the network achieve consensus asymptotically, respectively, for appropriate communication timedelay if the topology of weighted network is connected. Particularly, a tight upper bound on the communication time-delay that can be tolerated in the dynamic network is found. The consensus protocols are distributed in the sense that each agent only needs information from its neighboring agents, which reduces the complexity of connections between neighboring agents significantly. Numerical simulation results are provided to demonstrate the effectiveness and the sharpness of the theoretical results for second-order consensus in networks in the presence of communication time-delays.

关键词： second-order consensus protocols dynamic networks algebraic graph theory frequency domain analysis com-munication constraints.

On the tribological characteristics of dynamically loaded journal bearing with micropolar fluids

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Science china(Physics,Mechanics & Astronomy) 2004年第z1期47卷 45-50页

作者： WANG Xiaoli, WANG Kongying & ZHU KeqinSchool of Mechanical and Vehicular engineering, Beijing institute of technology, Beijing 100081, china department of engineering Mechanics, Tsinghua University, Beijing 100084, china Beijing Inst Technol Sch Mech & Vehicular Engn Beijing 100081 Peoples R China Tsing Hua Univ Dept Engn Mech Beijing 100084 Peoples R China

The addition of the additives to the lubricant oil to enhance the characteristics of the lubricant will influence the performance of the bearings. Based on the theory of micropolar fluids, the tribological characteristics of a dynamically-loaded journal bearing are numerically studied. Comparisons are made between the Newtonian fluids and the micropolar fluids. It is shown that for a dynamically-loaded journal bearing, the micropolar fluids yield an increase not only in the friction force, but also in the friction coefficient. In addition, the oil film pressure and the oil film thickness are obviously higher than that of Newtonian fluids.

关键词： micropolar fluids, dynamic loads journal bearing tribological characteristics.

A New Approach for Carrier Frequency Offset Estimation in OFDM communication System

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A New Approach for Carrier Frequency Offset Estimation in OF...