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On the functions of astrocyte-mediated neuronal slow inward currents 被引量:2
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作者 Balázs Pál 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第12期2602-2612,共11页
Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events a... Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocytic contribution) as ischemic currents and spreading depolarization also have a well-known pathophysiological role in worsening consequences of stroke,traumatic brain injury,or epilepsy.One might assume that slow inward currents occurring with low frequency under physiological conditions might contribute to synaptic plasticity and memory formation.However,to state this,more experimental evidence from greater neuronal networks or the level of the individual is needed.In this review,I aimed to summarize findings on slow inward currents and to speculate on the potential functions of it. 展开更多
关键词 ASTROCYTE cortical spreading depolarization gliotransmission GLUTAMATE neural synchronization NMDA receptor paroxysmal depolarizational shift slow inward current
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Altered synaptic currents,mitophagy,mitochondrial dynamics in Alzheimer's disease models and therapeutic potential of Dengzhan Shengmai capsules intervention 被引量:1
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作者 Binbin Zhao Dongfeng Wei +12 位作者 Qinghua Long Qingjie Chen Fushun Wang Linlin Chen Zefei Li Tong Li Tao Ma Wei Liu Linshuang Wang Caishui Yang Xiaxia Zhang Ping Wang Zhanjun Zhang 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第3期348-370,共23页
Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these patholog... Emerging research suggests a potential association of progression of Alzheimer's disease(AD)with alterations in synaptic currents and mitochondrial dynamics.However,the specific associations between these pathological changes remain unclear.In this study,we utilized Aβ42-induced AD rats and primary neural cells as in vivo and in vitro models.The investigations included behavioural tests,brain magnetic resonance imaging(MRI),liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)analysis,Nissl staining,thioflavin-S staining,enzyme-linked immunosorbent assay,Golgi-Cox staining,transmission electron microscopy(TEM),immunofluorescence staining,proteomics,adenosine triphosphate(ATP)detection,mitochondrial membrane potential(MMP)and reactive oxygen species(ROS)assessment,mitochondrial morphology analysis,electrophysiological studies,Western blotting,and molecular docking.The results revealed changes in synaptic currents,mitophagy,and mitochondrial dynamics in the AD models.Remarkably,intervention with Dengzhan Shengmai(DZSM)capsules emerged as a pivotal element in this investigation.Aβ42-induced synaptic dysfunction was significantly mitigated by DZSM intervention,which notably amplified the frequency and amplitude of synaptic transmission.The cognitive impairment observed in AD rats was ameliorated and accompanied by robust protection against structural damage in key brain regions,including the hippocampal CA3,primary cingular cortex,prelimbic system,and dysgranular insular cortex.DZSM intervention led to increased IDE levels,augmented long-term potential(LTP)amplitude,and enhanced dendritic spine density and length.Moreover,DZSM intervention led to favourable changes in mitochondrial parameters,including ROS expression,MMP and ATP contents,and mitochondrial morphology.In conclusion,our findings delved into the realm of altered synaptic currents,mitophagy,and mitochondrial dynamics in AD,concurrently highlighting the therapeutic potential of DZSM intervention. 展开更多
关键词 Alzheimer's disease Synaptic currents MITOPHAGY Mitochondrial fusion and fission Dengzhan Shengmai capsules
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Science Letters:Multi-frequency proportional-resonant (MFPR) current controller for PWM VSC under unbalanced supply conditions 被引量:14
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作者 HU Jia-bing HE Yi-kang 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第10期1527-1531,共5页
This letter presents a multi-frequency proportional-resonant (MFPR) current controller developed for PWM voltage source converter (VSC) under the unbalanced supply voltage conditions. The delta operator is used in... This letter presents a multi-frequency proportional-resonant (MFPR) current controller developed for PWM voltage source converter (VSC) under the unbalanced supply voltage conditions. The delta operator is used in place of the shift operator for the implementation of MFPR by using a low-cost fixed-point DSE The experimental results with an alternative control strategy validated the feasibility of the proposed MFPR current controller for the PWM VSC during voltage unbalance. 展开更多
关键词 PWM VSC multi-frequency proportional-resonant (MFPR) Voltage unbalance
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Probabilistic Calculation of Tidal Currents forWind Powered Systems Using PSO Improved LHS
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作者 Hongsheng Su Shilin Song Xingsheng Wang 《Energy Engineering》 EI 2024年第11期3289-3303,共15页
This paper introduces the Particle SwarmOptimization(PSO)algorithmto enhance the LatinHypercube Sampling(LHS)process.The key objective is to mitigate the issues of lengthy computation times and low computational accur... This paper introduces the Particle SwarmOptimization(PSO)algorithmto enhance the LatinHypercube Sampling(LHS)process.The key objective is to mitigate the issues of lengthy computation times and low computational accuracy typically encountered when applying Monte Carlo Simulation(MCS)to LHS for probabilistic trend calculations.The PSOmethod optimizes sample distribution,enhances global search capabilities,and significantly boosts computational efficiency.To validate its effectiveness,the proposed method was applied to IEEE34 and IEEE-118 node systems containing wind power.The performance was then compared with Latin Hypercubic Important Sampling(LHIS),which integrates significant sampling with theMonte Carlomethod.The comparison results indicate that the PSO-enhanced method significantly improves the uniformity and representativeness of the sampling.This enhancement leads to a reduction in data errors and an improvement in both computational accuracy and convergence speed. 展开更多
关键词 Latin hypercube sampling Monte Carlo simulation probabilistic currents particle swarm algorithm significant sampling
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Suppressing Leakage Currents and Improving Performance of Indoor Organic Photovoltaic Devices
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作者 WANG Xiang GAO Jiaxin +2 位作者 LI Zheng WANG Ming TANG Zheng 《Journal of Donghua University(English Edition)》 CAS 2024年第4期388-397,共10页
Organic photovoltaic(OPV) devices hold great promise for indoor light harvesting,offering a theoretical upper limit of power conversion efficiency that surpasses that of other photovoltaic technologies.However,the pre... Organic photovoltaic(OPV) devices hold great promise for indoor light harvesting,offering a theoretical upper limit of power conversion efficiency that surpasses that of other photovoltaic technologies.However,the presence of high leakage currents in OPV devices commonly constrains their effective performance under indoor conditions.In this study,we identified that the origin of the high leakage currents in OPV devices lay in pinhole defects present within the active layer(AL).By integrating an automated spin-coating strategy with sequential deposition processes,we achieved the compactness of the AL and minimized the occurrence of pinhole defects therein.Experimental findings demonstrated that with an increase in the number of deposition cycles,the density of pinhole defects in the AL underwent a marked reduction.Consequently,the leakage current experienced a substantial decrease by several orders of magnitude which achieved through well-calibrated AL deposition procedures.This enabled a twofold enhancement in the power conversion efficiency(PCE) of the OPV devices under conditions of indoor illumination. 展开更多
关键词 organic photovoltaic(OPV) indoor light harvesting pinhole defect leakage current shunt resistance
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Observation of Arctic surface currents using data from a surface drifting buoy
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作者 Hongxia Chen Lina Lin +7 位作者 Long Fan Wangxiao Yang Yinke Dou Bingrui Li Yan He Bin Kong Guangyu Zuo Na Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第1期70-79,共10页
During the 10th Chinese Arctic scientific expedition carried out in the summer of 2019,the surface current in the high-latitude areas of the Arctic Ocean was observed using a self-developed surface drifting buoy,which... During the 10th Chinese Arctic scientific expedition carried out in the summer of 2019,the surface current in the high-latitude areas of the Arctic Ocean was observed using a self-developed surface drifting buoy,which was initially deployed in the Chukchi Sea.The buoy traversed the Chukchi Sea,Chukchi Abyssal Plain,Mendeleev Ridge,Makarov Basin,and Canada Basin over a period of 632 d.After returning to the Mendeleev Ridge,it continued to drift toward the pole.Overall,the track of the buoy reflected the characteristics of the transpolar drift and Chukchi Slope Current,as well as the inertial flow,cross-ridge surface flow,and even the surface disorganized flow for some time intervals.The results showed that:(1)the transpolar drift mainly occurs in the Chukchi Abyssal Plain,Mendeleev Ridge,and western Canada Basin to the east of the ridge where sea ice concentration is high,and the average northward flow velocity in the region between 79.41°N and 86.32°N was 5.1 cm/s;(2)the average surface velocity of the Chukchi Slope Current was 13.5 cm/s,and while this current moves westward along the continental slope,it also extends northwestward across the continental slope and flows to the deep sea;and(3)when sea ice concentration was less than 50%,the inertial flow was more significant(the maximum observed inertial flow was 26 cm/s,and the radius of the inertia circle was 3.6 km). 展开更多
关键词 Chinese National Arctic Research Expedition(CHINARE) surface drifting buoy transpolar drift Chukchi Slope current inertial flow
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Absolute Wall Thickness Measurement of Conducting Plates Using Pulsed Eddy Currents
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作者 Victor-O. de Haan Riccardo Scottini 《Journal of Electromagnetic Analysis and Applications》 2024年第3期25-41,共17页
The method using pulsed eddy currents to determine the thickness of a conduction plate is extended to enable the simultaneous measurement of the plate thickness and material properties. For optimal performance, a prob... The method using pulsed eddy currents to determine the thickness of a conduction plate is extended to enable the simultaneous measurement of the plate thickness and material properties. For optimal performance, a probe must be designed depending on the thickness range that should be accessible. The need for a calibration of the material properties of a conducting plate to enable the measurement of its thickness has been removed. All that is needed is a probe with known dimensions and suitable hardware to create a current pulse and measure a transient magnetic induction. 展开更多
关键词 Pulsed Eddy currents Wall Thickness Absolute and Relative Measurements
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Inspection of aluminum alloys by a multi-frequency eddy current method 被引量:1
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作者 A.V.EGOROV V.V.POLYAKOV +4 位作者 D.S.SALITA E.A.KOLUBAEV S.G.PSAKHIE A.G.CHERNYAVSKII I.V.VOROBEI 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2015年第2期99-103,共5页
The paper proposes an experimental method of material inspection,which is based on digital processing of multi-frequency eddy current measurement data.The influences of various factors(conductivity,the gap between the... The paper proposes an experimental method of material inspection,which is based on digital processing of multi-frequency eddy current measurement data.The influences of various factors(conductivity,the gap between the sample surface and the sensor,the thickness of the sample) on the obtained hodographs are examined by taking the aluminum alloys for example,and the possibility of separation of various factors is analyzed.The results obtained are indicative of how much promise the proposed method offers for the inspection and testing of products made of aluminum alloys. 展开更多
关键词 铝合金 涡流法 检查 多频 数字处理 测量数据 电导率 传感器
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Morphology and Frictional Characteristics Under Electrical Currents of Al_2O_3/Cu Composites Prepared by Internal Oxidation 被引量:7
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作者 刘瑞华 宋克兴 +3 位作者 贾淑果 徐晓峰 郜建新 国秀花 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第3期281-288,共8页
Two Al2O3/Cu composites containing 0.24 wt.% Al2O3 and 0.60 wt.% Al2O3 separately are prepared by internal oxidation. Effects of sliding speed and pressure on the frictional characteristics of the composites and coppe... Two Al2O3/Cu composites containing 0.24 wt.% Al2O3 and 0.60 wt.% Al2O3 separately are prepared by internal oxidation. Effects of sliding speed and pressure on the frictional characteristics of the composites and copper against brass are investigated and compared. The changes in morphology of the sliding surface and subsurface are examined with scanning electron microscope (SEM) and energy dispersive X-ray spectrum (EDS). The results show that the wear resistance of the Al2O3/Cu composites is superior to that of copper under the same conditions, Under a given electrical current, the wear rate of Al2O3/Cu composites decreases as the Al2O3-content increases, However, the wear rates of the Al2O3/Cu composites and copper increase as the sliding speed and pressure increase under dry sliding condition. The main wear mechanisms for Al2O3/Cu composites are of abrasion and adhesion; for copper, it is adhesion, although wear by oxidation and electrical erosion can also be observed as the speed and pressure rise. 展开更多
关键词 Al2O3/Cu composite internal oxidation friction and wear surface morphology current carder
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An Analysis of Observed Ocean Currents Data and Numerical Simulation in the Offshore Area of Jiaonan 被引量:3
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作者 刘伟峰 孙英兰 张学庆 《Marine Science Bulletin》 CAS 2006年第2期1-11,共11页
Based on the diurnal consecutively observed data in the offshore area of Jiaonan in 2005, the paper tries to make a preliminary analysis of the specificity of ocean currents, tidal current property and residual curren... Based on the diurnal consecutively observed data in the offshore area of Jiaonan in 2005, the paper tries to make a preliminary analysis of the specificity of ocean currents, tidal current property and residual current property in the area in observing dates. Then on the basis of observed data analysis and by employing the split-step method, the paper conducts a numerical simulation of the tidal current field, which can show the M2 tidal constituent tidal wave system, current ellipse distribution, maximum current velocity distribution and time-dependent current field. The calculated results agree well with the observed data, which can on the one hand reflect the basic specificities of temporal and spatial distribution of the M2 tidal constituent current field to some extent, and, on the other hand, offer more information about the hydrodynamic condition. So the paper would provide a scientific basis for the making of sea environment protection plans in the offshore area of Jiaonan under certain conditions. 展开更多
关键词 ocean currents observed data numerical calculation Jiaonan
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Ocean surface currents retrieval based on the satellite remote sensing data 被引量:1
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作者 安玉柱 陈奕德 +2 位作者 张韧 王辉赞 陈建 《Marine Science Bulletin》 CAS 2013年第2期46-58,共13页
The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, ... The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, a global weekly 0.5°×0.5°ocean surface current product was obtained over the period 2000 - 2008 by combining the geostrophic currents estimated from sea surface height with Ekman current estimated from the wind stress. Particularly, weight functions were introduced when calculating the Ekman currents to eliminate the discontinuity near 25°S and 25°N. These satellite-derived currents have been compared with TAO current meter and the SCUD product, respectively. The comparison showed that satellite-derived currents not only could capture the characteristics of ocean surface currents but also had high accuracy and reliability. The result showed that this innovatory method was effective. 展开更多
关键词 satellite altimeter data QuikSCAT wind field surface geostrophic current Ekman current
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A study of impact of the reclamation and artificial island projects on tidal currents and sediment concentration in radial sand ridge field of the South Yellow Sea 被引量:3
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作者 赵强 何琴燕 +1 位作者 杨耀芳 黄秀清 《Marine Science Bulletin》 CAS 2015年第1期71-85,共15页
The two-dimensional hydrodynamic model, MIKE21, is applied to simulate the tidal currents and sediment concentration in the radial sand ridges of the South Yellow Sea. Results are in accordance with in situ observatio... The two-dimensional hydrodynamic model, MIKE21, is applied to simulate the tidal currents and sediment concentration in the radial sand ridges of the South Yellow Sea. Results are in accordance with in situ observations. Then the variations of tidal currents and suspended sediment concentration caused by reclamation and artificial islands projects are simulated. The results show that the impacts are limited around the project areas. After the projects, the fan-shaped, Jianggang centered tidal current pattern would be replaced by a pattern which is formed by two tidal paths. One locates at the Xiyang channel in north-south direction, and the other locates at the Huangshayang channel in east-west direction. The reclamation of Tiaozini separates the waters into south portion and north portion. The changes of sediment concentrations coincide with those of currents. Both the sediment concentrations and tidal currents increase at the northwest of Dongsha and the south of Gaoni, while both decrease at the north and south of Tiaozini, and the east and southwest of Dongsha. 展开更多
关键词 radial sand ridges RECLAMATION artificial island tidal currents suspended sediment concentration numerical modeling
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Analysis of tidal and residual currents across semi-enclosed bay mouth based on shipboard ADCP measurements 被引量:1
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作者 李希彬 孙晓燕 姚志刚 《Marine Science Bulletin》 2012年第2期37-45,共9页
Based on 25 hours shipboard ADCP measurements across semi-enclosed bay mouth(Kemen Channel), time series of tidal currents over 12 sites, which distribute evenly along the transect, were constructed to improve our u... Based on 25 hours shipboard ADCP measurements across semi-enclosed bay mouth(Kemen Channel), time series of tidal currents over 12 sites, which distribute evenly along the transect, were constructed to improve our understanding of tidal characteristics and residuals in this region. The tidal currents in Kemen Channel were identified as the regular semidiurnal and reversing tidal flows, with its behaviour more like standing waves. Moreover, the flood currents in the lower layers were found to be ahead of that in the upper layers and vice versa for ebb tides. The major of tidal ellipse for M2 constituent was found to be larger close to the southern side of the channel, with its incline also increasing toward the south. The signs of M4 constituent were also found mainly nearby the end points of this transect, indicating the importance of nonlinearity in tidal dynamics due to the shallower topography. A two-layer structure was found for the residual currents in Kemen Channel, flowing northeastwardly out of the Bay in upper 20m and southwestwardly into the bay in the lowers. Besides approximate 4.81×10^8 m^3 water exchanges were determined between the Luoyuan Bay and outer seas by the calculation of tidal flux through Kemen Channel. 展开更多
关键词 shipboard ADCP tidal currents RESIDUALS tidal transport
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Direct Tunneling Currents Through Gate Dielectrics in Deep Submicron MOSFETs 被引量:2
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作者 侯永田 李名复 金鹰 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2002年第5期449-454,共6页
A direct tunneling model through gate dielectric s in CMOS devices in the frame of WKB approximation is reported.In the model,an im proved one-band effective mass approximation is used for the hole quantization, wher... A direct tunneling model through gate dielectric s in CMOS devices in the frame of WKB approximation is reported.In the model,an im proved one-band effective mass approximation is used for the hole quantization, where valence band mixing is taken into account.By comparing to the experiments, the model is demonstrated to be applicable to both electron and hole tunneling c urrents in CMOS devices.The effect of the dispersion in oxide energy gap on the tunneling current is also studied.This model can be further extended to study th e direct tunneling current in future high-k materials. 展开更多
关键词 MOSFET direct tunneling current quantum effec t gate dielectrics
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Variations in tidal currents and suspended sediment concentration of the upper part of the North Channel of Changjiang Estuary over the past 10 years 被引量:1
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作者 刘高伟 程和琴 +3 位作者 计娜 乔远英 胡浩 王冬梅 《Marine Science Bulletin》 CAS 2015年第2期9-24,共16页
The tidal current duration (TCD) and velocity (TCV) and suspended sediment concentration (SSC) were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the Nor... The tidal current duration (TCD) and velocity (TCV) and suspended sediment concentration (SSC) were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the North Channel of Changjiang Estuary. They were assimilated with the measured data in 2003, 2004, 2006 and 2007, using the tidal range's proportion conversion. Variations in TCD and TCV, preferential flow and SSC have been calculated. Influences of typical engineering projects such as Qingcaosha fresh water reservoir, Yangtze River Bridge, and land reclamation on the ebb and flood TCD, TCV and SSC in the North Channel for the last 10 years are discussed. The results show that: (1) currently, in the upper part of North Channel, the ebb tide dominates; after the construction of the typical projects, ebb TCD and TCV tends to be larger and the vertical average ebb and flood SSC decrease during the flood season while SSC increases during the dry season; (2) changes in the vertical average TCV are mainly contributed by seasonal runoff variation during the flood season, which is larger in the flood season than that in the dry season; the controlling parameters of increasing ebb TCD and TCV are those large-scale engineering projects in the North Channel; variation in SSC may result mainly from the reduction of basin annual sediment loads, large-scale nearshore projects and so on. 展开更多
关键词 changes in tidal currents and suspended sediment concentration preferential flow data assimilation large-scale engineering projects Changjiang Estuary
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Three-dimensional numerical simulation of tides and tidal currents in the Lianzhou Bay and adjacent areas
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作者 宋德海 鲍献文 +1 位作者 张少峰 张春华 《Marine Science Bulletin》 CAS 2013年第1期1-15,共15页
A 3-D unstructured-grid, finite-volume coastal ocean model (FVCOM) was used to study the tides and tidal currents in the Lianzhou Bay and adjacent areas. The simulation results were in good agreement with observatio... A 3-D unstructured-grid, finite-volume coastal ocean model (FVCOM) was used to study the tides and tidal currents in the Lianzhou Bay and adjacent areas. The simulation results were in good agreement with observations. The co-tidal maps of K1 , O1 , and M2 indicated that K1 and O1 were mostly standing waves outside the Lianzhou Bay, while M2 had a largely propagating character. However, all three constituents became propagating waves when entering the Lianzhou Bay, due to the shallow waters. The tidal current ellipses showed the characters of K1 , O1 , and M2 constituents: K1 and O1 were rotating outside the bay, but rectilinear along the water channels inside the bay; M2 was mostly rectilinear over the whole area. The tidal-induced residual current shows the flow was divided into two branches by the Guantouling Peninsula: one turned to flow west; the other was blocked by the southern boundary of the peninsula, creating a clockwise circulation. In Lianzhou Bay, there were two circulation systems, a cyclonic one at the top of the bay and an anti-cyclonic at the mouth. 展开更多
关键词 Lianzhou Bay FVCOM tide tidal current residual tidal current
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The Theory of Field-Effect Transistors:XI. The Bipolar Electrochemical Currents(1-2-MOS-Gates on Thin-Thick Pure-Impure Base)
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作者 薩支唐 揭斌斌 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第3期397-409,共13页
The field-effect transistor is inherently bipolar, having simultaneously electron and hole surface and volume channels and currents. The channels and currents are controlled by one or more externally applied transvers... The field-effect transistor is inherently bipolar, having simultaneously electron and hole surface and volume channels and currents. The channels and currents are controlled by one or more externally applied transverse electric fields. It has been known as the unipolar field-effect transistor for 55-years since Shockley's 1952 invention,because the electron-current theory inevitably neglected the hole current from over-specified internal and boundary conditions, such as the electrical neutrality and the constant hole-electrochemical-potential, resulting in erroneous solutions of the internal and terminal electrical characteristics from the electron channel current alone, which are in gross error when the neglected hole current becomes comparable to the electron current, both in subthreshold and strong inversion. This report presents the general theory, that includes both electron and hole channels and currents. The rectangular ( x, y, z) parallelepiped transistors,uniform in the width direction (z-axis),with one or two MOS gates on thin and thick,and pure and impure base, are used to illustrate the two-dimensional effects and the correct internal and boundary conditions for the electric and the electron and hole electrochemical potentials. Complete analytical equations of the DC current-voltage characteristics of four common MOS transistor structures are derived without over-specification: the 1-gate on semi-infinite-thick impure-base (the traditional bulk transistor), the 1-gate on thin impure-silicon layer over oxide-insulated silicon bulk (SOI) ,the 1-gate on thin impure-silicon layer deposited on insulating glass (SOI TFT), and the 2-gates on thin pure-base (FinFETs). 展开更多
关键词 bipolar field-effect transistor theory MOS field-effect transistor simultaneous electron and hole surface and volume channels and currents surface potential two-section short-channel theory double-gate impure-base theory
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The spatio-temporal variation of wintertime subtidal currents in the western Taiwan Strait 被引量:6
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作者 SHEN Junqiang QIU Yun +2 位作者 GUO Xiaogang PAN Aijun ZHOU Xiwu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第11期4-13,共10页
A new data set of observations by six cruises of ship-mounted acoustic doppler current profiler(SADCP) and three 40 d long bottom-mounted ADCPs(BADCPs) is employed to reveal the spatiotemporal variability of tidal... A new data set of observations by six cruises of ship-mounted acoustic doppler current profiler(SADCP) and three 40 d long bottom-mounted ADCPs(BADCPs) is employed to reveal the spatiotemporal variability of tidal and subtidal currents in the western Taiwan Strait(TWS) during winter season. The results confirm the existence of intense cotidal lines for M2 tidal current, which is located north of 25°N. In this case, no existence of an amphidromic point can be identified. It is also revealed that the counter-wind current(CWC) can extend through the whole western TWS and even occupy the entire water column during winter monsoon relaxation. However,this CWC is observed to be thoroughly overwhelmed by the downwind China coastal current(CCC) during the two big monsoon bloom events in the winter of 2007, and the CCC consequently extends southward throughout the western TWS instead. Most importantly, the variation of the spatial extent for the CWC and the CCC in the western TWS is found to be well explained by the first two modes of the vector empirical orthogonal function(VEOF) analysis, that is, it is mainly controlled by a wind-driven quasi barotropic current as the first mode and slightly modulated by a relatively weak background current with a first-order baroclinic structure as the second mode. 展开更多
关键词 counter-wind current China coastal current M2 tidal current Taiwan Strait winter season
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Experi mental Study on Vortex-Induced Vibrations of Submarine Pipeline near Seabed Boundary in Ocean Currents 被引量:14
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作者 杨兵 高福平 +1 位作者 吴应湘 李东晖 《China Ocean Engineering》 SCIE EI 2006年第1期113-121,共9页
Unlike most previous studies on vortex-induced vibrations of a cylinder far from a boundary, this paper focuses on the influences of close proximity of a submarine pipeline to a rigid seabed boundary upon the dynamic ... Unlike most previous studies on vortex-induced vibrations of a cylinder far from a boundary, this paper focuses on the influences of close proximity of a submarine pipeline to a rigid seabed boundary upon the dynamic responses of the pipeline in ocean currents. The effects of gap-to-diameter ratio and those of the stability parameter on the amplitude and frequency responses of a pipeline are investigated experimentally with a novel hydro-elastic facility. A comparison is made between the present experimental results of the amplitude and frequency responses for the pipes with seabed boundary effects and those for wall-free cylinders given by Govardhan and Williamson (2000) and Anand (1985). The comparison shows that the close proximity of a pipeline to seabed has much influence on the vortex-induced vibrations of the pipeline. Both the width of the lock-in ranges in terms of Vr and the dimensionless amplitude ratio Amax/D become larger with the decrease of the gap-to-diameter ratio e/D, Moreover, the vibration of the pipeline becomes easier to occur and its amplitude response becomes more intensive with the decrease of the stability parameter, while tire pipeline frequency responses are affected slightly by the stability parameter. 展开更多
关键词 submarine pipeline vortex-induced vibrations ocean current SEABED
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Longshore Currents of Random Waves on Different Plane Beaches 被引量:6
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作者 邹志利 王淑平 +3 位作者 邱大洪 王艳 王风龙 董国海 《海洋工程:英文版》 2003年第2期265-276,共12页
Model tests and numerical calculation of longshore currents and wave heights produced by irregular waves on two beaches with slopes of 1:100 and 1:40 are studied. The cross-shore distributions of longshore current vel... Model tests and numerical calculation of longshore currents and wave heights produced by irregular waves on two beaches with slopes of 1:100 and 1:40 are studied. The cross-shore distributions of longshore current velocities and wave heights are given and the influences of wave heights, wave periods, and beach slopes on longshore currents are discussed. The discussion is also made on the influences of different eddy viscosity coefficients on the numerical results of longshore current velocities. 展开更多
关键词 coast current current coasts wave breaking
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