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Effect of focused ultrasound stimulation at different ultrasonic power levels on the local field potential power spectrum

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Chinese Physics B 2015年第8期24卷 646-650页

作者：袁毅路承彪李小俚 Institute of Electrical Engineering Yanshan University State Key laboratory of Cognitive Neuroscience and Learning & IDG/Mc Govern Institute for Brain Research Beijing Normal University Center for Collaboration and Innovation in Brain and Learning sciences Beijing Normal University

Local field potential(LFP) signals of the rat hippocampus were recorded under noninvasive focused ultrasound stimulation(FUS) with different ultrasonic powers. The LFP mean absolute power was calculated with the Welch algorithm at the delta, theta, alpha, beta, and gamma frequency bands. The experimental results demonstrate that the LFP mean absolute power at different frequency bands increases as the ultrasound power increases.

关键词： focused ultrasound stimulation local field potential power spectrum

Automatic Suppression of White Noise and Repetitive Pulses Interference in On-site Partial Discharge Monitoring

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Automatic Suppression of White Noise and Repetitive Pulses I...

11th International Conference on Electrical Machines and Systems

作者： Yuan Wan Zhaohui Li Mingjun Liu Yong Xu College of Hydroelectric and information Engineering Huazhong University of science and technology China

＜正＞The on-site partial discharge（PD）monitoring is the most powerful method to detect insulation faults in electrical power components,but it is often severely affected by external *** paper designs two algorithms for automatic detection and suppression of white noise interferences（WNI）and repetitive pulse interferences（RPI）in PD monitoring separately. The first algorithm for WNI suppression is based upon wavelet transform（WT）,and it solves the issues of mother wavelet selection,decomposition level determination and threshold selection during WT *** second one makes full use of the differences between PD pulses and RPI in pulse waveform and phase distribution,it takes three key steps including identifying pulses,clustering the similar pulses and analyzing pulse-phase histograms to separate *** of the two algorithms can be used in on-site PD monitoring.

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Predictive Fusion Weighted Method Based on Multisensor Time-Delay Network

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Predictive Fusion Weighted Method Based on Multisensor Time-...

第二十七届中国控制会议

作者： Liu Xikui,Li yan College of information & Engineering,Shandong University of science and technology,Qingdao 266510,P.R.China

Because the existing fusion methods based on network-delay often use the traditional synchronous fusion algorithms directly,it inevitably induces some problems,such as information delay,resource free,and bad real-time performance etc..Aiming at above problems this paper combined the predictive estimate with the technology of sequential weighted fusion at the basis of the existing ***,a new multisensor predictive weighted fusion method which could adapt to networkdelay was *** new method can not only avoid the disadvantages existing in the current data fusion method founded on network delay but also gain the better real-time predictive *** presents the process to deduce the sequential predictive weighted method based on ***,the computer simulation and theoretical analysis are used to show the practicability and advantage of the proposed fusion method.

关键词： Network-delay Multisensor system Linear unbiased estimate Optimal Predictive weighted fusion

EFFECT OF CURRENT SWEEP RATE ON CRITICAL CURRENT OF SUPERCONDUCTING Ag-Bi2223. TAPES

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南京大学学报(自然科学) 1999年第1期 124-125页

作者： Ding Qi Ding Shiying ( national laboratory of Solid State Microstrudures and Deprartment of Physics, Nanjing University, 210093. Nanjing, PRC)

Ｉｎｏｒｄｅｒｔｏｅｓｔａｂｌｉｓｈａｒｅｌｉａｂｌｅｓｔａｎｄａｒｄｍｅａｓｕｒｅｍｅｎｔｐｒｏｃｅｄｕｒｅｄｅｔｅｒｍｉｎｉｎｇｃｒｉｔｉｃａｌｃｕｒ－ｒｅｎｔ（Ｉｃ）ｆｏｒａｓｕｐｅｒｃｏｎｄｕｃｔｉｎｇｍａｔ... 详细信息

Ｉｎｏｒｄｅｒｔｏｅｓｔａｂｌｉｓｈａｒｅｌｉａｂｌｅｓｔａｎｄａｒｄｍｅａｓｕｒｅｍｅｎｔｐｒｏｃｅｄｕｒｅｄｅｔｅｒｍｉｎｉｎｇｃｒｉｔｉｃａｌｃｕｒ－ｒｅｎｔ（Ｉｃ）ｆｏｒａｓｕｐｅｒｃｏｎｄｕｃｔｉｎｇｍａｔｅｒｌａｌ，ａｌｏｔｏｆｅｆｏｒｔ...

关键词： V I curve I c d I /d t superconducting Ag Bi 2223.tape

Intelligent Control System of Water Level for Boiler Drum Based on OPC and MATLAB

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Intelligent Control System of Water Level for Boiler Drum Ba...

第三十届中国控制会议

作者： WU Mingliang~1,WU Mingyong~2,HUANG Jiankang~3.SHAO Ling~3.1.Electromechanical Academy,Lanzhou University of technology,Lanzhou 73.050,P.R.China 2.Peili Oil Academy of Engineering,Lanzhou City Academy,Lanzhou 73.050,P.R.China 3.Key laboratory of Non-ferrous Metal Alloys and Processing under the management for Ministry of Education,Lanzhou University of technology,Lanzhou 73.050,P.R.China

＜正＞WinCC configuration software and OPC technology as a breakthrough,communication integration of MATLAB and WinCC is *** real-time data exchange problem among different monitoring systems is solved based on OPC *** combine with strong engineering calculation ability of MATLAB and characteristics of real-time data collection for Siemens configuration software *** simulation results show that OPC is the communication interface between the Client MATLAB and Server *** can preferably realizes seamless transmission and experimental test of fuzzy self-adaptive PID intelligent control algorithm for boiler drum water level,and better satisfy real-time data,high efficiency requirements of process control for the boiler.

关键词： OPC technology MATLAB WinCC Real-Time Data Exchange Fuzzy Self-Adaptive PID

The transition to overshielding after sharp and gradual interplanetary magnetic field northward turning

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The transition to overshielding after sharp and gradual inte...

中国科学院地质与地球物理研究所第11届（2011年度）学术年会

作者： Yong Wei,Weixing Wan,Zuyin Pu,Minghua Hong,Qiugang Zong, Jianpeng Guo,Biqiang Zhao,and Zhipeng Ren 1 beijing national Observatory of Space Environment,Institute of Geology and Geophysics,Chinese Academy of sciences,beijing,China. 2 School of Earth and Space sciences,Peking University,beijing, China. 3.SIGMA Weather Group,State Key laboratory of Space Weather, CSSAR,Chinese Academy of sciences,beijing,China.

[1]Overshielding is referred to a shielding status,during which the dawnward shielding electric field dominates over the duskward penetration electric field in the inner magnetosphere,typically appearing when the interplanetary magnetic field(IMF) suddenly turns northward after a prolonged southward *** is expected that the transition to overshielding after IMF northward turning can be affected by the shape of northward turning(sharp or gradual).Moreover,the initial shielding status(undershielding or goodshielding) prior to the transition may also have influence on the *** we analyze two groups of cases,in which the transitions appear after sharp(duration less than 5 min) and gradual(duration more than 3. min) northward *** group includes two cases,in which the transition initiated from undershielding and *** cases show that(1) the beginning of the transition to overshielding coincides with shaip IMF northward turning but appears in the midst of gradual IMF northward turning;(2) the transition from goodshielding to overshielding is always associated with convection electric field drop and/or polar cap shrinkage,regardless of the shape of IMF northward turning;and(3. the typical solar wind condition in which the IMF suddenly turns northward after a prolonged southward orientation is neither a necessary condition nor a sufficient condition for ***,we will discuss the effect of substorm processes on overshielding.

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GNSS浮标海面高测量中海浪的影响分析

测绘科学技术学报 2018年第1期35卷 12-16页

作者：管斌孙中苗刘晓刚秦显平信息工程大学河南郑州450001 地理信息工程国家重点实验室陕西西安710054 西安测绘研究所陕西西安710054

以骑浪式浮标为对象,研究了海浪对于GNSS浮标测量海面高的影响。以单向规则波的形态简化模拟了海浪以及GNSS浮标随海浪的运动过程。在某固定海况条件下,比较了浮标天线参考点高不同时海面高测量误差;在浮标天线参考点高固定的条件下,比... 详细信息

以骑浪式浮标为对象,研究了海浪对于GNSS浮标测量海面高的影响。以单向规则波的形态简化模拟了海浪以及GNSS浮标随海浪的运动过程。在某固定海况条件下,比较了浮标天线参考点高不同时海面高测量误差;在浮标天线参考点高固定的条件下,比较了不同海况时海面高测量误差;给出了GNSS浮标在卫星高度计定标应用中的建议。结果表明:浮标测量海面高误差与天线参考点高成正比,海浪周期越长、波高越小时,测量误差越小;天线参考点高为5 cm,海浪振幅为1 m、周期为7 s、传播速度为5 m/s时,测量海面高平均比实际海面高低0.4 mm;相同浮标在小于3.4级的海况条件下,由海浪引起的海面高测量偏差约在1 mm以内,对于卫星高度计定标工作而言,该误差影响可以忽略。

关键词： GNSS浮标海面高天线参考点有效波高高度计定标

Micro-mechanisms of residual oil mobilization by viscoelastic fluids

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Petroleum science 2008年第1期5卷 56-61页

作者： Zhang Lijuan Yue Xiang＇an Guo Fenqiao Key laboratory of Petroleum Engineering Ministry of Education China University of Petroleum Beijing 102249 China Development Department Sinopec Exploration and Production Research Institute Beijing 100083 China

Four typical types of residual oil, residual oil trapped in dead ends, oil ganglia in pore throats, oil at pore corners and oil film adhered to pore walls, were studied. According to main pore structure characteristics and the fundamental morphological features of residual oil, four displacement models for residual oil were proposed, in which pore-scale flow behavior of viscoelastic fluid was analyzed by a numerical method and micro-mechanisms for mobilization of residual oil were discussed. Calculated results indicate that the viscoelastic effect enhances micro displacement efficiency and increases swept volume. For residual oil trapped in dead ends, the flow field of viscoelastic fluid is developed in dead ends more deeply, resulting in more contact with oil by the displacing fluid, and consequently increasing swept volume. In addition, intense viscoelastic vortex has great stress, under which residual oil becomes small oil ganglia, and finally be carried into main channels. For residual oil at pore throats, its displacement mechanisms are similar to the oil trapped in dead ends. Vortices are developed in the depths of the throats and oil ganglia become smaller. Besides, viscoelastic fluid causes higher pressure drop on oil ganglia, as a driving force, which can overcome capillary force, consequently, flow direction can be changed and the displacing fluid enter smaller throats. For oil at pore corners, viscoelastic fluid can enhance displacement efficiency as a result of greater velocity and stress near the corners. For residual oil adhered to pore wall, viscoelastic fluid can provide a greater displacing force on the interface between viscoelastic fluid and oil, thus, making it easier to exceed the minimum interfacial tension for mobilizing the oil film.

关键词： Viscoelastic chemical flooding displacement mechanism residual oil swept volume

Influence of Temperature on Sulfate Attack of Limestone Filler Cement Mortar

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Journal of Wuhan University of technology(Materials science) 2006年第Z1期21卷 80-85页

作者：高小建 School of Materials science and Engineering Harbin Institute of technology Harbin 150006 China Key laboratory of Silicate Materials science and Engineering Wuhan University of Technology Wuhan 430070 China

Mortar prisms were made with three different cementitious materials (with or without mineral admixture) plus 3.% mass of limestone filler. After 28 days of curing in water at room temperature, the mortars were submerged in 2% magnesium sulfate solution at different temperatures (5℃, 20℃and alternate temperature between 5℃and 20℃) for a year. The appearance and strength development were measured on these immersed prisms at intervals, and samples selected from the surface of prisms were examined by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results show that the influence of temperature on the resistance to sulfate attack of mortar is related to the binder compositions. A higher temperature leads to a quicker strength loss and appearance deterioration of the mortar without mineral admixture. For blended cements, a higher temperature is favorable for the pozzolanic reaction of mineral admixture and the overall deterioration of mortar is reduced with the increasing temperature. When the mineral admixture has a lower reactivity, such influence of temperature on the resistance to sulfate attack of mortar containing admixtures becomes greater. At the three different solution temperatures, two blended cements show significantly improved resistances to sulfate attack. After 1 year of exposure to magnesium sulfate solutions, the formation of thaumasite was checked in the OPC mortars at both 5℃and 20℃. It is concluded that the thaumasite formation is not limited to structures at low temperature (less than 15℃).

关键词： cement mortar limestone filler mineral admixture sulfate attack temperature thaumasite