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Electrodeposition of Gold to Conformally Fill High-Aspect-Ratio Nanometric Silicon Grating Trenches: A Comparison of Pulsed and Direct Current Protocols 被引量:2
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作者 Sami Znati Nicholas Chedid +3 位作者 Houxun Miao Lei Chen Eric E. Bennett Han Wen 《Journal of Surface Engineered Materials and Advanced Technology》 2015年第4期207-213,共7页
Filling high-aspect-ratio trenches with gold is a frequent requirement in the fabrication of X-ray optics as well as micro-electronic components and other fabrication processes. Conformal electrodeposition of gold in ... Filling high-aspect-ratio trenches with gold is a frequent requirement in the fabrication of X-ray optics as well as micro-electronic components and other fabrication processes. Conformal electrodeposition of gold in sub-micron-width silicon trenches with an aspect ratio greater than 35 over a grating area of several square centimeters is challenging and has not been described in the literature previously. A comparison of pulsed plating and constant current plating led to a gold electroplating protocol that reliably filled trenches for such structures. 展开更多
关键词 PULSED ELECTROPLATING Gold ELECTROPLATING High Aspect Ratio TRENCHES Gold Electrodepostion Di-rect current Electrodeposition PULSED vs. Direct current ELECTROPLATING Atomic LAYER Deposition Platinum Seed LAYER Silicon TRENCH Gratings TRENCH FILLING Grating FILLING ALD Adhesive LAYER
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Purification,application and current market trend of natural graphite:A review 被引量:19
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作者 Allah D.Jara Amha Betemariam +1 位作者 Girma Woldetinsae Jung Yong Kim 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2019年第5期671-689,共19页
Graphite has a stacked planar sp2-hybridized C6 ring structure,displaying a polymorphism with rhombohedral,hexagonal,and turbostratic.Based on its structure-property relationship,it affords a variety of technologicall... Graphite has a stacked planar sp2-hybridized C6 ring structure,displaying a polymorphism with rhombohedral,hexagonal,and turbostratic.Based on its structure-property relationship,it affords a variety of technologically innovative applications or performances in industries,such as lithium-ion batteries,fuel cells,two dimensional graphene,water purification,electronics,fiber optics,spintronics,refractories,electrical products,electric vehicles,etc.The monetary value of graphite depends largely on carbon content and flake size.However,the physical separation of graphite from its ore body is known to be very expensive,energy intensive and time-consuming.Hence,this study extensively describes a current purification method for producing high-quality graphite material with impurities reaching about 10–100 mg/kg,attracting a lot of end users.It also describes the potential applications of graphite materials and identifies the future scope of a new market,depending on material purity.Finally,the current and future graphite-mining countries are investigated in details. 展开更多
关键词 GRAPHITE PURIFICATION GRAPHENE LITHIUM-ION BATTERY market Technology
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Exact Traveling Wave Solutions of Nano-Ionic Solitons and Nano-Ionic Current of MTs Using the exp(-φ (ξ ))-Expansion Method
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作者 Emad H. M. Zahran 《Advances in Nanoparticles》 2015年第2期25-36,共12页
In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to... In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to be special values, the solitary wave solutions are derived from the exact traveling wave solutions. The validity and reliability of the method are tested by its applications to Nano-ionic solitons wave’s propagation along microtubules in living cells and Nano-ionic currents of MTs which play an important role in biology. 展开更多
关键词 The exp(-φ (ξ )) -Expansion Method Nano-Solitons of IONIC Waves Propagation along Microtubules in Living Cells Nano-Ionic currents of MTS Traveling WAVE SOLUTIONS KINK and Anti KINK WAVE SOLUTIONS
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The Classical Hall Effect in Multiply-Connected Plane Regions Part II: Spiral Current Streamlines
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作者 Udo Ausserlechner 《Journal of Applied Mathematics and Physics》 2019年第10期2231-2264,共34页
Multiply-connected Hall plates show different phenomena than singly connected Hall plates. In part I (published in Journal of Applied Physics and Mathematics), we discussed topologies where a stream function can be de... Multiply-connected Hall plates show different phenomena than singly connected Hall plates. In part I (published in Journal of Applied Physics and Mathematics), we discussed topologies where a stream function can be defined, with special reference to Hall/Anti-Hall bar configurations. In part II, we focus on topologies where no conventional stream function can be defined, like Corbino disks. If current is injected and extracted at different boundaries of a multiply-connected conductive region, the current density shows spiral streamlines at strong magnetic field. Spiral streamlines also appear in simply-connected Hall plates when current contacts are located in their interior instead of their boundary, particularly if the contacts are very small. Spiral streamlines and circulating current are studied for two complementary planar device geometries: either all boundaries are conducting or all boundaries are insulating. The latter case means point current contacts and it can be treated similarly to singly connected Hall plates with peripheral contacts through the definition of a so-called loop stream function. This function also establishes a relation between Hall plates with complementary boundary conditions. The theory is explained by examples. 展开更多
关键词 Circulating current Corbino Disk Corbino Images Corbinotron Doubly CONNECTED Hall Plate Loop current Multiply CONNECTED Non-Peripheral Contacts Reverse Magnetic Field RECIPROCITY SPIRAL STREAMLINES Stream Function
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Exact Traveling Wave Solutions for Nano-Solitons of Ionic Waves Propagation along Microtubules in Living Cells and Nano-Ionic Currents of MTs
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作者 Emad H. M. Zahran 《World Journal of Nano Science and Engineering》 2015年第3期78-87,共10页
In this work, the extended Jacobian elliptic function expansion method is used as the first time to evaluate the exact traveling wave solutions of nonlinear evolution equations. The validity and reliability of the met... In this work, the extended Jacobian elliptic function expansion method is used as the first time to evaluate the exact traveling wave solutions of nonlinear evolution equations. The validity and reliability of the method are tested by its applications to nano-solitons of ionic waves propagation along microtubules in living cells and nano-ionic currents of MTs which play an important role in biology. 展开更多
关键词 Extended Jacobian Elliptic Function Expansion Method Nano-Solitons of IONIC WAVES PROPAGATION ALONG MICROTUBULES in Living Cells Nano-Ionic currents of MTS Traveling Wave Solutions
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A Mathematical Model for Magnetohydrodynamic Convection Flow in a Rotating Horizontal Channel with Inclined Magnetic Field, Magnetic Induction and Hall Current Effects
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作者 Swapan Kumar Ghosh Osman Anwar Bég Abdul Aziz 《World Journal of Mechanics》 2011年第3期137-154,共18页
Closed-form and asymptotic solutions are derived for the steady, fully-developed hydromagnetic free and forced convection flow in a rotating horizontal parallel-plate channel under the action of an inclined magnetic f... Closed-form and asymptotic solutions are derived for the steady, fully-developed hydromagnetic free and forced convection flow in a rotating horizontal parallel-plate channel under the action of an inclined magnetic field and constant pressure gradient along the longitudinal axis of the channel. The magnetic field is strong enough to generate Hall current effects and the magnetic Reynolds number of sufficient magnitude that induced magnetic field effects are also present. Secondary flow is present owing to the Hall current effect. The channel plates are also taken to be electrically-conducting. The conservation equations are formulated in an (x, y, z) coordinate system and non-dimensionalized using appropriate transformations. The resulting non-dimensional coupled ordinary differential equations for primary and secondary velocity components and primary and secondary induced magnetic field components and transformed boundary conditions are shown to be controlled by the dimensionless pressure gradient parameter (px), Hartmann number (M2), Grashof number (G), Hall current parameter (m), rotational parameter (K2), magnetic field inclination (&#920), and the electrical conductance ratios of the upper (&#9201) and lower (&#9202) plates. Solutions are derived using the method of complex variables. Asymptotic solutions are also presented for very high rotation parameter and Hartmann number of order equal to unity, for which Ekman-Hartmann boundary layers are identified at the plates. A parametric study of the evolution of velocity and induced magnetic field distributions is undertaken. It is shown that generally increasing Hall current effect (m) serves to accentuate the secondary (cross) flow but oppose the primary flow. An increase in rotational parameter (K2) is also found to counteract primary flow intensity. An elevation in the Grashof number i.e. free convection parameter (G) is shown to aid the secondary induced magnetic field component (Hz);however there is a decrease in magnitudes of the primary induced magnetic field component (Hx) with increasing Grashof number. Increasing inclination of the applied magnetic field (&#920, is also found to oppose the primary flow (u1) but conversely to strongly assist the secondary flow (w1). Both critical primary (Gcx) and secondary (Gcz)Grashof numbers are shown to be reduced with increasing inclination of the magnetic field (&#920), increasing Hall parameter (m) and rotational parameter (K2). Applications of the study arise in rotating MHD induction power generators and also astrophysical flows. 展开更多
关键词 HYDROMAGNETIC Flow HALL current Electrical CONDUCTANCE Free And Forced Convection Critical Grashof Number Rotation Complex Variables Asymptotic Analysis Ekman-Hartmann Boundary Layers ASTRONAUTICS
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Temperature Effects on the Electrical Performance of Large Area Multicrystalline Silicon Solar Cells Using the Current Shunt Measuring Technique 被引量:1
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作者 Hala Mohamed Abdel Mageed Ahmed Faheem Zobaa +2 位作者 Mohamed Helmy Abdel Raouf Abla Hosni Abd El-Rahman Mohamed Mamdouh Abdel Aziz 《Engineering(科研)》 2010年第11期888-894,共7页
The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shun... The temperature effects on the electrical performance of a large area multicrystalline silicon solar cell with back-contact technology have been studied in a desert area under ambient conditions using the current shunt measuring technique. Therefore, most of the problems encountered with traditional measuring techniques are avoided. The temperature dependency of the current shunt from 5oC up to 50oC has been investigated. Its temperature coefficient proves to be negligible which means that the temperature dependency of the solar cell is completely independent of the current shunt. The solar module installed in a tilted position at the optimum angle of the location, has been tested in two different seasons (winter and summer). The obtained solar cell short circuit current, open circuit voltage and output power are correlated with the measured incident radiation in both seasons and all results are discussed. 展开更多
关键词 Large Area MULTICRYSTALLINE Silicon Solar Cell current SHUNT Measuring Technique Temperature Effects SHORT CIRCUIT current Open CIRCUIT Voltage Accumulated Power INCIDENT Radiation
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On the functions of astrocyte-mediated neuronal slow inward currents
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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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The Forward and Inverse Problem Based on Magneto-Acoustic Tomography with Current Injection
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作者 Hui Xia Guoqiang Liu +3 位作者 Xin Huang Liang Guo Yanjiu Yang Minhua Lu 《Journal of Biomedical Science and Engineering》 2017年第5期97-105,共9页
The Magneto-acoustic Tomography with Current Injection (MAT-CI) is a new biological electrical impedance imaging technique that combines Electrical Impedance Tomography (EIT) with Ultrasonic Imaging (UI), which posses... The Magneto-acoustic Tomography with Current Injection (MAT-CI) is a new biological electrical impedance imaging technique that combines Electrical Impedance Tomography (EIT) with Ultrasonic Imaging (UI), which possesses the non-invasive and high-contrast of the EIT and the high-resolution of the UI. The MAT-CI is expected to acquire high quality image and embraces a wide application. Its principle is to put the conductive sample in the Static Magnetic Field(SMF) and inject a time-varying current, during which the SMF and the current interact and generate the Lorentz Force that inspire ultrasonic signal received by the ultrasonic transducers positioned around the sample. And then according to related reconstruction algorithm and ultrasonic signal, electrical conductivity image is obtained. In this paper, a forward problem mathematical model of the MAT-CI has been set up to deduce the theoretical equation of the electromagnetic field and solve the sound source distribution by Green’s function. Secondly, a sound field restoration by Wiener filtering and reconstruction of current density by time-rotating method have deduced the Laplace’s equation that caters to the current density to further acquire the electrical conductivity distribution image of the sample through iteration method. In the end, double-loop coils experiments have been conducted to verify its feasibility. 展开更多
关键词 Magneto-Acoustic Tomography With current Injection Axial SYMMETRY Model the FORWARD and Inverse Problem of Electromagnetic Field RECONSTRUCTION IMAGE RECONSTRUCTION Electrical Conductivity IMAGE
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Seasonal Difference of the Deep Currents in the Luzon Strait during October 2008-January 2009 and July-August 2009
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作者 Yaochu Yuan Weibing Guan +2 位作者 Chenghao Yang Yu-Heng Tseng Huiqun Wang 《Atmospheric and Climate Sciences》 2019年第3期284-297,共14页
Based on direct current measurements from two separated cruises in October 2008-January 2009 and July-August 2009, we obtained a valuable deep current observation of the Luzon Strait (LS). Rectified wavelet power spec... Based on direct current measurements from two separated cruises in October 2008-January 2009 and July-August 2009, we obtained a valuable deep current observation of the Luzon Strait (LS). Rectified wavelet power spectra analysis (RWPSA) and the geostrophic current calculation are used to study the deep current. We find that the deep current differs in different seasons. The current is strongest in autumn (October-November) and weaker in summer (July-August) and in winter (December-January). The cyclonic and anti-cyclonic meander with different subtidal current directions plays an important role in the seasonal difference of the deep current in the LS. The observed seasonal difference of the deep current in the LS is connected with the deep current observed at the western boundary of the northern Philippine Basin and is also linked with the overflow near the central Bashi Channel and Luzon Trough. The RWPSA of the long observation suggests the dominant periods of 8 d, 19 d in the deep current. The dynamical cause of the resulting velocity distribution at 1850 and 1760 m is the pressure field and bottom topography steering. The observed deep current agrees well with the geostrophic current calculation. 展开更多
关键词 LUZON STRAIT Long Measurement of DEEP currentS SEASONAL DIFFERENCE Rectified Wavelet Power Spectra Analysis Dynamical Cause of Resulting DEEP current Distribution
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Harnessing the Market Potential of the Bamboo Industry in Central Luzon, Philippines: An Analysis of the Internal and External Environment
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作者 Edgelly Galvez Vitug Sarah Calma Alvarez 《Open Journal of Ecology》 2024年第5期395-418,共24页
The bamboo industry in Central Luzon holds significant promise for economic development and environmental sustainability. This study aims to analyze the internal and external factors influencing the bamboo industry in... The bamboo industry in Central Luzon holds significant promise for economic development and environmental sustainability. This study aims to analyze the internal and external factors influencing the bamboo industry in the region through SWOT and PESTLE analyses. Based on a focus group discussion involving key industry players, the study explores the industry’s strengths, weaknesses, opportunities, and threats, as well as political, economic, social, technological, legal, and environmental factors. Findings reveal the importance of comprehensive strategies that address political stability, economic growth, consumer awareness, technological advancement, legal compliance, and environmental sustainability. Recommendations include capacity-building for production and marketing, the establishment of bamboo treatment facilities, and advocacy for supportive policies. By addressing these factors, the bamboo industry in Central Luzon can realize its potential for socio-economic development and environmental stewardship. 展开更多
关键词 BAMBOO SWOT Analysis PESTLE Analysis Business Environment Value Addition SUSTAINABILITY market Potential
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The Essence of Optimism of The Economists and Investors with Regard to the Economy of Russia
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作者 Tenkovskaya Lyudmila Igorevna 《Journal of Economic Science Research》 2019年第4期1-9,共9页
The gross domestic product of Russia,expressed in US dollars,indicates problems in the Russian economy associated with the decline in oil prices on the world energy market and the consequences of the sanctions of the ... The gross domestic product of Russia,expressed in US dollars,indicates problems in the Russian economy associated with the decline in oil prices on the world energy market and the consequences of the sanctions of the United States and the European Union against Russia.The crisis situation of the Russian economy has a negative impact on the income of the population of country,represented mainly by wages.However,an economist or investor may be optimistic about Russian economic development in the medium term.This optimism is related to the economic policy of the United States.The expansion of the United States economy within the global space,based on economic growth,requires maintaining inflation within the target level and weakening the US dollar.These tasks are solved with the help of soft monetary policy of the US Federal Reserve System.The reduction of interest rates by the US Federal Reserve System against the background of inflation of the target level and the devaluation of the US dollar will contribute to economic growth in the United States,because it will lead to the depreciation of public debt,lower consumption of imports,increase in exports and trade balance,growth of production,income,consumption.The economic policy of the United States,which contributes to the devaluation of the US dollar,will also reduce the US dollar against the ruble.The optimistic view of investors-economists on the Russian economy is due to a significant strengthening of the ruble against the US dollar.Consequently,in the medium term,the gross domestic product and wages of citizens of Russia,expressed in US dollars,will significantly increase,and the purchasing power of the national currency of the country will also increase.This growth may continue until the next election of a new President of the United States in november 2020.After the election of the new President of the United States,there is a high probability of sanctions against Russia and of decline in oil prices in the world energy market in accordance with the future economic policy of the United States–two main reasons for the sharp strengthening of the US dollar against the ruble,which will cause a deeper economic crisis in Russia in the medium and long term. 展开更多
关键词 RUSSIA UNITED STATES US Federal Reserve System Gross domestic product Average monthly nominal wages Core price index of personal consumption expenditures Monetary policy DEVALUATION of the US dollar USD/RUB currency pair OIL prices World OIL market UNITED STATES sanctions against RUSSIA
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Transcranial Direct Current Stimulation: Effects on Motor and Non-Motor Symptoms of Parkinson’s Disease
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作者 Fayda Protásio Carlos Alberto Bezerra Tomaz +3 位作者 Joaquim Brasil-Neto Pedro Brandão Nasser Allam Maria Clotilde Henriques Tavares 《Journal of Behavioral and Brain Science》 2024年第5期135-160,共26页
Introduction: In the last thirty years, brain neuromodulation techniques have been used as an alternative to pharmacological treatment of neurological disorders. Parkinson’s disease (PD) is a neurodegenerative disord... Introduction: In the last thirty years, brain neuromodulation techniques have been used as an alternative to pharmacological treatment of neurological disorders. Parkinson’s disease (PD) is a neurodegenerative disorder leading to bradykinesia, rest tremor, postural changes, and non-motor symptoms such as depression, anxiety, sleep disorders, pain, and cognitive decline that compromises executive functions (EFs), responsible for the orderly execution of behaviors and tasks of daily life and intentional and directed actions. To this date, a few studies with transcranial direct current stimulation (tDCS) have shown beneficial effects in PD patients concerning specific motor and non-motor symptoms, targeting the motor cortex and/or prefrontal regions. Objective: The main objective of this study was to evaluate the effects of left prefrontal tDCS across a broad spectrum of motor and non-motor symptoms of PD using established validated scales. Method: Single-blind randomized clinical trial with 18 volunteers with PD, aged between 45 and 80 years (66.1 ± 9.65), who met inclusion and exclusion criteria. Participants were submitted to assessments of motor and non-motor functions employing psychometric scales and tests to evaluate EFs and were randomly divided into two groups: control (sham stimulation) and experimental (active stimulation). All participants were involved in three separate tDCS sessions. The anode was positioned over the left dorsolateral prefrontal cortex and the cathode over the right supraorbital region, with a direct current intensity of 2 mA, lasting 20 minutes. At the end of the three sessions, all participants were reassessed. Results: Significant effects of tDCS on non-motor functions were observed for cognition (verbal fluency of actions, clock copy test, appointment by visual confrontation, and verbal memory with immediate free recall) and subjective assessment of sleep quality (overall restlessness and discomfort in the arms and legs at night, leg and arm cramps at night and distressing dreams). There was also an improvement in the rate of errors and successes for congruent and incongruent stimuli of the Stroop Test. The beneficial effects on motor function were decreased rigidity, improved gait, and greater agility in the finger-tapping test. Conclusion: Three tDCS sessions showed positive results for participants with PD, producing significant improvements in various motor and non-motor functions, including sleep quality, cognition, and EFs. Additionally, the present results indicate that tDCS neuromodulation of the left dorsolateral prefrontal cortex region is feasible, safe, and provides significant objective benefits for PD patients. 展开更多
关键词 Parkinsons Disease NEUROMODULATION Transcranial Direct current StimulationtDCS Movement Disorders MOOD SLEEP COGNITION
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Experimental investigation on ablation characteristics of coated and uncoated steel under 30/80 μs impulse current
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作者 戴明秋 刘亚坤 +2 位作者 傅正财 刘娟 毕晓蕾 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第7期123-134,共12页
The ablation tests on coated and uncoated Q235 B steel sheets were conducted under 30/80 μs impulse current simulating the lightning first return stroke current, aimed at further understanding the ablation characteri... The ablation tests on coated and uncoated Q235 B steel sheets were conducted under 30/80 μs impulse current simulating the lightning first return stroke current, aimed at further understanding the ablation characteristics of steel and investigating the impact of anti-corrosion coating on these characteristics. Ablation characteristics were investigated through the macroscopic morphology and x-ray diffraction patterns on the surface of damaged zones, the microstructure and micro Vickers hardness on the cross-section of damaged zones, and the maximum rear-face temperature of sample sheets. It can be concluded that the ablation areas of uncoated sheet consist of the melted layer and the heat-affect layer. These ablation areas include not only the area ablated directly by the arc root, of which the depth is deeper, but also the area forming due to the splashing of molten steel, of which the depth is shallower and decreases when the area’s distance from the arc attachment point increases. For coated sheet, coating materials have decomposed and evaporated forming an ablation pit on the sheet surface, in which the steel surface is exposed, and zinc filler of coating primer has infused into the exposed surface. The ablation diameter of uncoated sheet relates to the amplitude of the 30/80 μs impulse current in quadratic function, while for coated sheet, the relation is linear. In general, under the 30/80 μs impulse current, the coating can decrease the energy injected from the arc to the steel sheet and reduce the melting and splashing of steel. As a result, the ablation severity of uncoated sheet is severer than that of coated sheet. 展开更多
关键词 arc ablation effect ANTI-CORROSION coating LIGHTNING first return stroke current 30/80 μs IMPULSE current Q235B STEEL microstructure x-ray diffraction
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Advancement in Wide Area Monitoring Protection and Control Using PMU’s Model in MATLAB/SIMULINK
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作者 Waheed Ur Rahman Muhammad Ali +7 位作者 Amjad Ullah Hafeez Ur Rahman Majid Iqbal Haseeb Ahmad Adnan Zeb Zeeshan Ali M. Ahsan Shahzad Beenish Taj 《Smart Grid and Renewable Energy》 2012年第4期294-307,共14页
A big step forward to improve power system monitoring and performance, continued load growth without a corresponding increase in transmission resources has resulted in reduced operational margins for many power system... A big step forward to improve power system monitoring and performance, continued load growth without a corresponding increase in transmission resources has resulted in reduced operational margins for many power systems worldwide and has led to operation of power systems closer to their stability limits and to power exchange in new patterns. These issues, as well as the on-going worldwide trend towards deregulation of the entire industry on the one hand and the increased need for accurate and better network monitoring on the other hand, force power utilities exposed to this pressure to demand new solutions for wide area monitoring, protection and control. Wide-area monitoring, protection, and control require communicating the specific-node information to a remote station but all information should be time synchronized so that to neutralize the time difference between information. It gives a complete simultaneous snap shot of the power system. The conventional system is not able to satisfy the time-synchronized requirement of power system. Phasor Measurement Unit (PMU) is enabler of time-synchronized measurement, it communicate the synchronized local information to remote station. 展开更多
关键词 WIDE Area MONITORING Protection and CONTROL (WAMPAC) Phasor Measurement uNit (PMU) WIDE Area MONITORING (WAM) Global Positioning System (GPS) WIDE Area CONTROLLER (WAC) Local Area CONTROLLER (LAC) Phase Angle MONITORING (PAM) Automatic Generation CONTROL (AGC) Circuit Breaker (CB) current TRANSFORMERS (CTs) Potential TRANSFORMERS (PTs)
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Improved Ladder Wave Modulation of Circulating Current Suppressing Control Strategy of MMC
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作者 Pinggang Song Yunfeng Li Lina Wang 《Energy and Power Engineering》 2013年第4期1176-1181,共6页
This paper partitions the arm current of MMC into uncontrollable current and controllable current. The former is determined by the load that can’t be controlled by taking any control strategy. The later caused by the... This paper partitions the arm current of MMC into uncontrollable current and controllable current. The former is determined by the load that can’t be controlled by taking any control strategy. The later caused by the unbalanced total inserted voltage of three arms can be controlled by some improved algorithms. The conclusion based on the researching the essence of circulating current is reached that change the number of the inserted sub-modules in each phase can suppress the circulating current. Combined with the improved ladder wave modulation, a novel circulating current suppression strategy particularly for the inverter station is developed. The improved strategy can adapt to load changes and reduce the circulating current and output voltage THD of MMC ac terminals greatly without increasing any peripheral circuits. Finally, the simulation model of 100 submodules in each phase is constructed in MATLAB and the simulation results verify the correctness and effectiveness of the modified control algorithm. 展开更多
关键词 Modular MULTILEVEL Converter High Voltage Direct current Transmission CIRCULATING current Module CHANGING Selection Algorithm Double Frequency NEGATIVE Component
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An Empirical Assessment of the Impact of Nigerian all Share Index, Market Capitalization, and Number of Equities on Gross Domestic Product
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作者 Obubu Maxwell Obiora-Ilouno Happiness +1 位作者 Uzuke Chinwendu Alice Ikediuwa Udoka Chinedu 《Open Journal of Statistics》 2018年第3期584-602,共19页
A stock exchange is an exchange where stock brokers and traders can buy and sell shares of stock, bonds, and other securities. All listings are included in the Nigerian Stock Exchange All Shares index. In terms of mar... A stock exchange is an exchange where stock brokers and traders can buy and sell shares of stock, bonds, and other securities. All listings are included in the Nigerian Stock Exchange All Shares index. In terms of market capitalization, the Nigerian Stock Exchange is the third largest stock exchange in Africa. Objectives: The paper assesses the impact of Nigerian Stock Market (all share index, market capitalization, and number of equities) on Gross domestic product (Economic Growth). Materials and Methods: Regression analysis and ordinary least square technique were employed. Result and Discussion: The series was stationary at 1%, 5%, and 10% α level;the residuals were normally distributed but not serially correlated at 5% α level. All Share Index, Market Capitalization and Total Number of listed Equities have a joint and individual significant effect on Economic Growth (Gross Domestic Product) with Total Number of listed Equities having a negative (opposite) linear relationship with the Gross Domestic Product. The Durbin-Watson statistics (R2 = 0.9910 = 1.3686) suggest that the model is not spurious and it is devoid of positive and negative autocorrelation (DW = 1.3686 > dl = 1.07 and DW = 1.5033 ?-?du = 2.17). Therefore, it can produce meaningful result when used for forecasting a positive relationship between gross domestic product, all share index and market capitalization with a 99.1% R-square value. Significant Positive connection between all share index, market capitalization, the number of equities and gross domestic product suggests that government policies and bills aimed towards rapid development of the capital market should be initiated. 展开更多
关键词 NIGERIAN Stock market Gross Domestic Product market Capitalization ALL SHARE INDEX Augmented Dickey-Fuller TEST Breusch-Godfrey TEST Serial Correlation Lm TEST
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Cystic fibrosis transmembrane conductance regulator functional evaluations in a G542X+/-IVS8Tn:T7/9 patient with acute recurrent pancreatitis 被引量:2
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作者 Sara Caldrer Gabriella Bergamini +12 位作者 Angela Sandri Silvia Vercellone Luca Rodella Angelo Cerofolini Francesco Tomba Filippo Catalano Luca Frulloni Mario Buffelli Gloria Tridello Hugo de Jonge Baroukh Maurice Assael Claudio Sorio Paola Melotti 《World Journal of Clinical Cases》 SCIE 2019年第22期3757-3764,共8页
BACKGROUND Acute recurrent pancreatitis(ARP)is characterized by episodes of acute pancreatitis in an otherwise normal gland.When no cause of ARP is identifiable,the diagnosis of"idiopathic"ARP is given.Mutat... BACKGROUND Acute recurrent pancreatitis(ARP)is characterized by episodes of acute pancreatitis in an otherwise normal gland.When no cause of ARP is identifiable,the diagnosis of"idiopathic"ARP is given.Mutations in the cystic fibrosis transmembrane conductance regulator(CFTR)gene increase the risk of ARP by 3-to 4-times compared to the general population,while cystic fibrosis(CF)patients present with a 40-to 80-times higher risk of developing pancreatitis.CASE SUMMARY In non-classical CF or CFTR-related disorders,CFTR functional tests can help to ensure a proper diagnosis.We applied an individualized combination of standardized and new CFTR functional bioassays for a patient referred to the Verona CF Center for evaluation after several episodes of acute pancreatitis.The CFTR genotype was G542X+/-with IVS8Tn:T7/9 polymorphism.The sweat(Cl-)values were borderline.Intestinal current measurements were performed according to the European Cystic Fibrosis Society Standardized Operating Procedure.Recent nasal surgery for deviated septum did not allow for nasal potential difference measurements.Lung function and sputum cultures were normal;azoospermia was excluded.Pancreas divisum was excluded by imaging but hypoplasia of the left hepatic lobe was detected.Innovative tests applied in this case include sweat rate measurement by image analysis,CFTR function in monocytes evaluated using a membrane potential-sensitive fluorescent probe,and the intestinal organoids forskolin-induced swelling assay.CONCLUSION Combination of innovative CFTR functional assays might support a controversial diagnosis when CFTR-related disorders and/or non-classical CF are suspected. 展开更多
关键词 Recurrent acute PANCREATITIS CYSTIC FIBROSIS CYSTIC FIBROSIS transmembraneconductance regulator function Intestinal current ORGANOIDS SWEAT test Controversialdiagnosis Case report
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Influence of Current Density on the Photocatalytic Activity of Nd:TiO_(2) Coatings
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作者 施渊吉 ZHANG Zhen +2 位作者 DAI Yunzhong LI Jingxiao CHEN Zeyu 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期32-38,共7页
The Nd:TiO_(2 )PEO coatings were formed in a phosphate-based electrolyte with the addition of Nd_(2)O_(3 )under the current density of 150,200,250 and 300 m A/cm^(2).SEM results showed that the micropores decreased on... The Nd:TiO_(2 )PEO coatings were formed in a phosphate-based electrolyte with the addition of Nd_(2)O_(3 )under the current density of 150,200,250 and 300 m A/cm^(2).SEM results showed that the micropores decreased on quantity and increased on scale with the increasing current density.AFM results revealed that the roughness of the coatings increased with the increasing current density.Phase and composition analysis showed that the Nd:TiO_(2) coatings were mainly composed of anatase and rutile phase.And the anatase phase content has reached the maximum value at the current density of 250 m A/cm^(2).XPS results indicated that Ti2p spin-orbit components of the Nd:TiO_(2) coatings are shifted towards higher binding energy,compared with the pure TiO_(2) coating,suggesting that some of the Nd^(3+)ions are combined with TiO_(2) lattice and led to dislocation.Photocatalytic test showed that the photocatalytic activity of Nd:TiO_(2) coatings varied in the same pattern with the anatase content variation in Nd:TiO_(2) coatings.The photocatalytic experiment results show that the photocatalytic activity of Nd:TiO_(2) coatings can be greatly enhanced with moderate amount of Nd^(3+).However,excessive amount of Nd^(3+)does not have an effective impact on the photoctalytic activity improvement. 展开更多
关键词 PEO current density AFM XPS Nd:TiO_(2) PHOTOCATALYTIC
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Revisiting aluminum current collector in lithium-ion batteries:Corrosion and countermeasures
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作者 Shanglin Yang Jinyan Zhong +1 位作者 Songmei Li Bin Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期610-634,I0014,共26页
With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant attentions.While the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary m... With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant attentions.While the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary materials,such as current collector corrosion,should not be disregarded.Therefore,it is necessary to conduct a comprehensive review in this field.In this review,from the perspectives of electrochemistry and materials,we systematically summarize the corrosion behavior of aluminum cathode current collector and propose corresponding countermeasures.Firstly,the corrosion type is clarified based on the properties of passivation layers in different organic electrolyte components.Furthermore,a thoroughgoing analysis is presented to examine the impact of various factors on aluminum corrosion,including lithium salts,organic solvents,water impurities,and operating conditions.Subsequently,strategies for electrolyte and protection layer employed to suppress corrosion are discussed in detail.Lastly and most importantly,we provide insights and recommendations to prevent corrosion of current collectors,facilitate the development of advanced current collectors and the implementation of next-generation high-voltage stable LIBs. 展开更多
关键词 Lithium-ion battery Aluminum current collector CORROSION Electrochemical performance ELECTROLYTE Protective layer
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