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Topological Tail Pressure for Asymptotically Sub-additive Continuous Potentials
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作者 DING DAN-DAN MA XIAN-FENG +1 位作者 CHEN ER-CAI Lei Feng-chun 《Communications in Mathematical Research》 CSCD 2017年第4期327-339,共13页
We define the topological tail pressure and the conditional pressure for asymptotically sub-additive continuous potentials on topological dynamical systems and obtain a variational principle for the topological tail p... We define the topological tail pressure and the conditional pressure for asymptotically sub-additive continuous potentials on topological dynamical systems and obtain a variational principle for the topological tail pressure without any additional assumptions. 展开更多
关键词 asymptotically sub-additive potential tail pressure entropy structure variational principle
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Mass Increase with Strong and Gravitational Potentials, and Mass Defect with Electromagnetic Potential
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作者 Hany Ali Hussein 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1079-1094,共16页
The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons,... The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons, & mesons) and their components (quarks), mass difference between nucleus and its individual components (protons and neutrons), massless of gamma photons, abnormal masses of mesons and bosons, and the excess in galaxy masses (dark matter). Also, this proposal shows the exact relation between mass and energy: Strong Potential=−3.04mc2| Electric Potential |=−5.57×10−3mc2Gravitational Potential=−1.22×10−7mc2where m represents the excess in mass due to strong potential, or gravitational potential and represents the decrease in mass due to electromagnetic potential. Released energy here equals potential energy and doesn’t equal decrease in mass using the formula E = mc2. Released energy is transferred to heat, photons, kinetic energy… Finally, proposal will try to describe the relation between photon energy and mass of its components using the general equation of kinetic energy: Photon Energy=1/2mc2m is the sum of the individual masses of its components, while the total mass of photon is zero. 展开更多
关键词 Mass Defect Dark Matter PHOTON Gamma Photon Strong potential Gravitational potential Electromagnetic potential QUARKS Mesons BOSONS Deuterium Proton Neutron
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Median Nerve Somatosensory Evoked Potentials in Patients with Chiari Malformation
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作者 Mustafa Harun Sahin Gonul Vural +1 位作者 Serdar Barakli Sadiye Gumusyayla 《World Journal of Neuroscience》 CAS 2024年第1期24-32,共9页
Abnormal SEP reflects dysfunction of the medial lemniscus and posterior cervical cord. These structures are likely to be affected in Chiari malformation. Therefore, SEP abnormalities may provide valuable information i... Abnormal SEP reflects dysfunction of the medial lemniscus and posterior cervical cord. These structures are likely to be affected in Chiari malformation. Therefore, SEP abnormalities may provide valuable information in patients with CM. However, the consistency of SEP abnormality or normality with the damage is a matter of research. Knowing whether median nerve somatosensory evoked potential (SEP) is useful in revealing subclinical damage in patients with Chiari malformation is important in the treatment and follow-up plan of the disease. The aim of this study was to investigate the relationship between median nerve SEP values and the severity of cerebellar ectopia in patients with Chiari type 1 malformation. Median nerve SEP values were obtained from 30 healthy individuals and 146 individuals with Chiari malformation. The cerebellar ectopia degree and McRae line length were measured. SEP values were not significantly different between groups. The McRae line was found to be significantly shorter in the control group than in the Chiari malformation group (p = 0.031). There was no correlation between the degree of cerebellar ectopia and the length of the McRae line (r = 0.002, p = 0.979). Neither cerebellar ectopy degree nor McRae line length had a relationship with SEP values (r = -0.153, p = 0.066;r = -0.056, p = 0.500, respectively). There was no difference in cerebellar ectopy degree or SEP values between the groups with cerebellar ectopy with and without a syrinx (p = 0.899;p = 0.080, respectively). Likewise, McRae line length was not found to be related to the presence of a syrinx (p = 0.139). Median nerve SEP examination was not beneficial for diagnosing asymptomatic-oligosymptomatic Chiari malformation as a subclinical injury, whether accompanied by syringomyelia or not. 展开更多
关键词 Chiari Malformation Cerebellar Ectopy Somatosensory Evoked potential
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A robust method for evaluating the potentials of 15-minute cities:Implications for sustainable urban futures
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作者 Jianying Wang Mei-Po Kwan +1 位作者 Gezhi Xiu Fangxu Deng 《Geography and Sustainability》 CSCD 2024年第4期597-606,共10页
The‘15-minute city’(15minC)concept,which aspires to bring essential services within reach via a 15-minute walk for all residents,represents a pivotal paradigm shift in sustainable urban development.However,the achie... The‘15-minute city’(15minC)concept,which aspires to bring essential services within reach via a 15-minute walk for all residents,represents a pivotal paradigm shift in sustainable urban development.However,the achievability of this concept for different cities varies considerably across diverse population distributions,urban contexts,and development priorities.In this study,we propose a robust method for evaluating a city’s 15minC potential-a city’s capability to achieve widespread 15-minute accessibility while maintaining an optimal balance between resource efficiency and resident accessibility.We employ the Location Set Covering Problem optimization model to analyze the resources required to achieve full coverage of 15-minute accessibility and the knee point detection algorithm to assess a city’s 15minC potential.Across 23 major Chinese cities,our method exhibits a sharp sensitivity to delineate distinct 15minC potentials.It reveals that cities’current 15minC development level doesn’t align with their inherent potential uniformly.Key determinants include how well current facility locations match population centers and the population density in remote areas.Further,reducing facility constructions by twothirds has only a marginal impact on accessibility,emphasizing the need for tailored,data-driven planning in effective and sustainable urban development based on the distinct potentials of cities.Our approach prioritizes resource efficiency,minimizing the inefficient use of facilities that serve only a small portion of residents while maximizing the benefits of the 15minC and therefore has significant implications for a sustainable urban future. 展开更多
关键词 15-Minute city Development potential SUSTAINABILITY Efficiency
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Thermal conductivity of GeTe crystals based on machine learning potentials
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作者 张健 张昊春 +1 位作者 李伟峰 张刚 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期104-107,共4页
GeTe has attracted extensive research interest for thermoelectric applications.In this paper,we first train a neuroevolution potential(NEP)based on a dataset constructed by ab initio molecular dynamics,with the Gaussi... GeTe has attracted extensive research interest for thermoelectric applications.In this paper,we first train a neuroevolution potential(NEP)based on a dataset constructed by ab initio molecular dynamics,with the Gaussian approximation potential(GAP)as a reference.The phonon density of states is then calculated by two machine learning potentials and compared with density functional theory results,with the GAP potential having higher accuracy.Next,the thermal conductivity of a GeTe crystal at 300 K is calculated by the equilibrium molecular dynamics method using both machine learning potentials,and both of them are in good agreement with the experimental results;however,the calculation speed when using the NEP potential is about 500 times faster than when using the GAP potential.Finally,the lattice thermal conductivity in the range of 300 K-600 K is calculated using the NEP potential.The lattice thermal conductivity decreases as the temperature increases due to the phonon anharmonic effect.This study provides a theoretical tool for the study of the thermal conductivity of GeTe. 展开更多
关键词 machine learning potentials thermal conductivity molecular dynamics
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Quantum-mechanical understanding on structure dependence of image potentials of single-walled boron nitride nanotubes
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作者 Yu Zhang Zhiman Zhang +2 位作者 Weiliang Wang Shaolin Zhang Haiming Huang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第12期467-475,共9页
The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays,molecule-based sensors,and so forth.To... The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays,molecule-based sensors,and so forth.To achieve a comprehensive understanding of surface potentials at the nano-emitters during the tunneling process,in this study we systematically investigated the image potentials of single-walled boron nitride nanotubes with different edges,diameters and lengths in the frame of a composite first-principles calculation.The image potentials of zigzag single-walled boron nitride nanotubes are found to be dependent on the non-equivalent sides.Only the image potentials of isolated armchair single-walled boron nitride nanotube can be well fitted with the image potential of an ideal metal sphere of a size comparable to the tube diameter.On the contrary,the image potentials of zigzag and grounded armchair single-walled boron nitride nanotubes exhibit a strong length-dependence characteristic and are significantly different from that of an ideal metal sphere,which originates from the significant axial symmetry breaking of induced charge at the tip for the long tube.The correlation between the testing electron and electronic structure of single-walled boron nitride nanotube has also been discussed. 展开更多
关键词 boron nitride nanotubes quantum chemistry image potentials structure dependence
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Clinical characteristics and analysis of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss in different ages
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作者 Yan-Zhuo Zhang Ya-Bo Wang +6 位作者 Jing-Lei Fang Yue-Tang Wang Gui-Fang Li Ran-Ran Liu Shu-Jing Shi Chun-Hua Wang Yong-Tao Tian 《World Journal of Clinical Cases》 SCIE 2024年第19期3760-3766,共7页
BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studi... BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studies analyzing vestibularevoked myogenic potentials(VEMPs)in SSHL patients across various age groups.AIM To investigate vestibular condition in SSHL patients across various age demographics.METHODS Clinical data of 84 SSHL patients were investigated retrospectively.Audiometry,cervical vestibular evoked myogenic potentials(c-VEMPs),and ocular vestibular evoked myogenic potentials(o-VEMPs)were conducted on these patients.Parameters assessed included the latencies of P1 and N1 waves,as well as the amplitudes of P1–N1 waves.Moreover,the study evaluated the influence of factors such as sex,affected side,configuration of hearing loss,and presence of accompanying vertigo.RESULTS Among the 84 SSHL patients,no significant differences were observed among the three groups in terms of gender,affected side,and the presence or absence of vertigo.Group II(aged 41–60 years)had the highest number of SSHL cases.The rates of absent o-VEMPs in the affected ears were 20.83%,31.58%,and 22.72%for the three age groups,respectively,with no statistically significant difference among them.The rates of absent c-VEMPs in the affected ears were 8.3%,34.21%,and 18.18%for the three age groups,respectively,with significant differences.In the unaffected ears,there were differences observed in the extraction rates of o-VEMPs in the unaffected ears among the age groups.In the three age groups,no significant differences were noted in the three age groups in the latencies of P1 and N1 waves or in the amplitude of N1–P1 waves for c-VEMPs and o-VEMPs,either on the affected side or on the unaffected side,across the three age groups.CONCLUSION The extraction rate of VEMPs is more valuable than parameters.Regardless of the presence of vertigo,vestibular organs are involved in SSHL.Notably,SSHL patients aged 41–60 appear more susceptible to damage to the inferior vestibular nerve and saccule. 展开更多
关键词 Sudden sensorineural hearing loss Cervical vestibular evoked myogenic potential Ocular vestibular evoked myogenic potential VERTIGO Pure tone audiometry
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Tetrathiafulvalene esters with high redox potentials and improved solubilities for non-aqueous redox flow battery applications
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作者 Weikang Hu Jiaqi Xu +3 位作者 Nanjie Chen Zongcai Deng Yuekun Lai Dongyang Chen 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第5期899-908,共10页
The exploitation of high performance redox-active substances is critically important for the development of non-aqueous redoxflow batteries.Herein,three tetrathiofulvalene(TTF)derivatives with different substitution gr... The exploitation of high performance redox-active substances is critically important for the development of non-aqueous redoxflow batteries.Herein,three tetrathiofulvalene(TTF)derivatives with different substitution groups,namely TTF diethyl ester(TTFDE),TTF tetramethyl ester(TTFTM),and TTF tetraethyl ester(TTFTE),are prepared and their energy storage properties are evaluated.It has been found that the redox potential and solubility of these TTF derivatives in conventional carbonate electrolytes increases with the number of ester groups.The battery with a catholyte of 0.2 mol L^(-1) of TTFTE delivers a specific capacity of more than 10 Ah L^(-1) at the current density of 0.5 C with two discharge voltage platforms locating at as high as 3.85 and 3.60 V vs.Li/Liþ.Its capacity retention can be improved from 2.34 Ah L^(-1) to 3.60 Ah L^(-1) after 100 cycles by the use of an anion exchange membrane to block the crossover of TTF species.The excellent cycling stability of the TIF esters is supported by their well-delocalized electrons,as revealed by the density function theory calculations.Therefore,the introduction of more and larger electron-withdrawing groups is a promising strategy to simultaneously increase the redox-potential and solubility of redox-active ma-terials for non-aqueous redoxflow batteries. 展开更多
关键词 Non-aqueous redox flow batteries Tetrathiofulvarene Redox potential SOLUBILITY Substituent effect
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The Aharonov-Bohm Effect: An Exploration of Quantum Interference and Electromagnetic Potentials
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作者 Bahman Zohuri 《Journal of Energy and Power Engineering》 CAS 2024年第3期79-87,共9页
The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,ev... The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,even in regions where the magnetic field B is zero.This effect demonstrates that quantum particles are influenced not only by the fields directly present but also by the potentials associated with those fields.In the AB effect,an electron beam is split into two paths,with one path encircling a solenoid and the other bypassing it.Despite the absence of a magnetic field in the regions traversed by the beams,the vector potential A associated with the magnetic flux Φ through the solenoid induces a phase shift in the electron’s wave function.This phase shift,quantified by △φ=qΦ/hc,manifests as a change in the interference pattern observed in the detection screen.The phenomenon underscores the principle of gauge invariance in QED(quantum electrodynamics),where physical observables remain invariant under local gauge transformations of the vector and scalar potentials.This reinforces the notion that the vector potential A has a profound impact on quantum systems,beyond its classical role.This article outlines the AB effect,including its theoretical framework,experimental observations,and implications.The focus on the role of the vector potential in quantum mechanics provides a comprehensive understanding of this important phenomenon. 展开更多
关键词 AB effect vector potential(A) magnetic flux(Φ) quantum phase shift gauge invariance electromagnetic potentials interference pattern scalar fields longitudinal waves QED
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Masseter Vestibular evoked myogenic potentials: A new tool to assess the vestibulomasseteric reflex pathway
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作者 Aishwarya Nagarajan Sujeet Kumar Sinha 《Journal of Otology》 CAS CSCD 2024年第1期46-54,共9页
Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also ... Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also reviews the contemporary researches involving the clinical applications of the mVEMP. Conclusions: Masseter VEMP is an evolving yet clinically promising neuro-otology test tool that has recently gained more research interest and is considered an additional tool to diagnose various vestibular disorders. Masseter VEMP assesses the functional integrity of the acoustic-masseteric and vestibulo-masseteric reflex pathways. The mVEMP could be used as a complementary test to evaluate the same peripheral generator as the cervical VEMP but a different central pathway i.e., vestibulo-trigeminal pathway. Various research studies that have experimented on parameters such as the effect of different electrode montages(zygomatic vs mandibular configurations), stimulation rates, filter settings and stimuli used to evoke mVEMP have been discussed in this article that could assist in the optimization of a comprehensive clinical protocol. The latency and the amplitude of mVEMP waveforms serve as significant parameters in differentiating normals from those of the clinical populations. Along with the cVEMPs and oVEMPs, mVEMP might help diagnose brainstem lesions in REM Sleep behaviour disorders, Multiple Sclerosis and Parkinson's disease. However, further studies are required to probe in this area of research. 展开更多
关键词 Masseter vestibular evoked myogenic potentials(mVEMP) Vestibulo-masseteric pathway Acoustic-masseteric pathway
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Mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration
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作者 JoséM.Izquierdo 《Neural Regeneration Research》 SCIE CAS 2025年第3期805-807,共3页
The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of previously replication-competent cells. 展开更多
关键词 LATIN potentiAL lasting
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Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
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作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation potential function Variational method Normalized solution
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Entrepreneurship training:its influences on innovation potentials among nursing students
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作者 Asmaa Abdel Rahman Abdel Rahman Dalia Abdallah Abdelatief 《Frontiers of Nursing》 2024年第1期85-98,共14页
Objective:To evaluate the influences of entrepreneurship training on the innovation potential among nursing students.Methods:A quasi-experimental design was utilized to conduct this study.The study was conducted in th... Objective:To evaluate the influences of entrepreneurship training on the innovation potential among nursing students.Methods:A quasi-experimental design was utilized to conduct this study.The study was conducted in the classroom at the faculty of nursing,and the“i Hub”center at Ain Shams University(ASU)in Cairo,Egypt.A purposive sample of 42 nursing students who participated in the“Ain Shams University-innovate”competition from the Faculty of Nursing of ASU were included in this study.Data collection tools included(1)Nursing students'innovation skills assessment questionnaire and(2)Innovative projects evaluation tool.Results:There was a statistically significant difference between the mean scores of nursing students'total innovation skills pre-and post-implementation of entrepreneurship training,where P-value<0.05.Conclusions:The results of the current study support the research hypothesis because the implementation of entrepreneurship training positively affects nursing students'innovation potential.Developing entrepreneurship education in nursing and integrating it into nursing programs will stimulate creativity,innovation,and entrepreneurship among nursing students and health care services. 展开更多
关键词 entrepreneurship training innovation potentials nursing students creative skills energy/motivation
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Understanding the local structure and thermophysical behavior of Mg-La liquid alloys via machine learning potential
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作者 Jia Zhao Taixi Feng Guimin Lu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第2期439-449,共11页
The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La a... The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic(DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained deep potential(DP) model was thoroughly evaluated through several aspects, including root-mean-square errors(RMSEs), energy and force data, and structural information comparison results;the results indicate the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80at% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated,which provides new guidance for related studies. 展开更多
关键词 magnesium-lanthanum liquid alloys local structure macroscopic properties thermodynamic behavior deep potential mo-lecular dynamic simulation
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SUB-ADDITIVE PRESSURE ON A BOREL SET
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作者 陈阳洋 赵云 郑文巧 《Acta Mathematica Scientia》 SCIE CSCD 2015年第5期1203-1213,共11页
The goal of this paper is to investigate topological conditional pressure of a continuous transformation as defined for sub-additive potentials. This study presents a vari- ational inequality for sub-additive topologi... The goal of this paper is to investigate topological conditional pressure of a continuous transformation as defined for sub-additive potentials. This study presents a vari- ational inequality for sub-additive topological conditional pressure on a closed subset, which is the other form of the variational principle for the sub-additive topological pressure pre- sented by Cao, Feng, and Huang in [9]. Moreover, under some additional assumptions, this result can be generalized to the non-compact case. 展开更多
关键词 sub-additive potentials topological pressure conditional entropy VARIATIONALINEQUALITY
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Dependent mechanism of Chinese prepositions processing in the brain:evidence from event-related potentials
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作者 方环海 张荣萍 +3 位作者 方环非 高明阳 郑敏 孙潇羽 《Neuroscience Bulletin》 SCIE CAS CSCD 2007年第5期282-286,共5页
Objective To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and "... Objective To compare the event-related potentials (ERPs) waves of verbs and prepositions in the brain. Methods We recorded ERPs in the brain while participants judged the legality of the collocation for verbs and "preposition". Results Both verbs and prepositions elicited a negativity at the frontal site in 230-330 ms and 350-500 ms window. No difference was seen in 230-330 ms and 350-500 ms window; In difference waves, a negativity was elicited in the left and fight hemisphere at about 270-400 ms and 470-600 ms window for both open and closed-class words. Conclusion These may demonstrate that prepositions in modem Chinese are probably not a separate class from verbs and that N280 may be not a specific component for only prepositions (or closed-class words). 展开更多
关键词 CHINESE PREPOSITIONS VERBS event-related potentials difference waves
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Growth and crystallization behaviors of anodic oxide films on sputter-deposited titanium at very low potentials
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作者 邢俊恒 夏正斌 +2 位作者 李辉 王莹莹 钟理 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第11期3286-3292,共7页
Growth and crystallization of titanium anodized films were studied by performing the anodization of the sputter-deposited titanium samples under cyclic voltammetry (CV) mode at very low potentials. The surface featu... Growth and crystallization of titanium anodized films were studied by performing the anodization of the sputter-deposited titanium samples under cyclic voltammetry (CV) mode at very low potentials. The surface features, crystalline behaviors and chemical compositions of the formed anodic oxide layers were detected by AFM, SE and XPS. It was found that the structure of the titanium anodized films is crystalline, even though the maximum oxidation potential ((Pmax) is very low (as low as 1000 mY). Both enlarging the applied voltage and reducing the potential scanning rate are beneficial for the growth and crystallization of titanium oxide films. It was thought that the internal compressive stress, other than the local joule heating accepted for many researchers, is the main force of stimulating the crystallization of anodic titanium oxide films at very low potentials. 展开更多
关键词 anodization sputter-deposited titanium crystallization low potential cyclic voltammetry (CV)
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Nitrification potentials of Chinese tea orchard soils and their adjacent wasteland and forest soils 被引量:12
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作者 XUE Dong GAO Yangmei +1 位作者 YAO Huaiying HUANG Changyong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第9期1225-1229,共5页
To investigate the nitrifying activities of different soil types, soil samples collected from 8-, 50- and 90-year old tea orchards, the adjacent wasteland, and 90-year old forest were measured for their nitrification ... To investigate the nitrifying activities of different soil types, soil samples collected from 8-, 50- and 90-year old tea orchards, the adjacent wasteland, and 90-year old forest were measured for their nitrification potentials using the conventional soil incubation and the liquid incubation method. Among different soil types, the nitrification potential of soil in tea orchards was higher than that of wasteland and forest soils. The slurry shaken liquid incubation method was confirmed to be more accurate and have reliable results than the soil incubation. Interestingly, experimental result revealed that the generally applied pH value of 7.2 for the liquid media was not the optimal pH for these acid soils with a strong buffer capacity. This suggested that tea orchard soils may have nitrifiers requiring pHneutral condition for the best activity. Our data also showed that treatment with the commonly used nitrogen fertilizer urea significantly improved nitrification potential of the soils; such enhancement effect was stronger on all of three tea orchard soils than on wasteland and forest soils, and also stronger on the younger (8- and 50-year old) tea orchard soils than on the older one (90-year old). 展开更多
关键词 tea orchard WASTELAND forest nitrification potential UREA
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Substituent Effects on Reduction Potentials of Meta-substituted and Para-substituted Benzylideneanilines 被引量:1
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作者 王琳艳 曹朝暾 曹晨忠 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第2期260-264,I0002,共6页
Effects of meta-substituent of 3,4'/4,3'/3,3'-substituted benzylideneanilines (XBAYs) on the electrochemical reduction potentials (E(Red)) were investigated, in which 49 samples of target compounds were synth... Effects of meta-substituent of 3,4'/4,3'/3,3'-substituted benzylideneanilines (XBAYs) on the electrochemical reduction potentials (E(Red)) were investigated, in which 49 samples of target compounds were synthesized, and their reduction potentials were measured by cyclic voltammetry. The substituent effects on the E(Red) of target compounds were analyzed and an optimality equation with four parameters (Hammett constant a of X, Hammett constant a of Y, excited-state substituent constant σexCC of X, and the substituent specific cross-interaction effect △σexCC2 between X and Y) was obtained. The results show that the factors affecting the E(Red) of 3,4'/4,31/3,3P-substituted XBAYs are different from those of 4,4'-substituted XBAYs. For 3,4'/4,3'/3,3'-substituted XBAYs, σ(X) and σ(Y) must be employed, and the contribution of △σexCC2 is important and not negligible. Compared with 4,4'-substituted XBAYs, X group contributes less to 3,4'/4,3'/3,3'-substituted XBAYs, while Y group contributes more to them. Additionally, it was observed that either para-substituted XBAYs or meta-substituted XBAYs, the substituent effects of X are larger than those of Y on the E(Red) of substituted XBAYs. 展开更多
关键词 3 4r/4 3'/3 3'-substituted benzylideneanilines Substituent effects Electro-chemical reduction potentials Cyclic voltammetry Excited-state substituent constant
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Observing the steady-state visual evoked potentials with a compact quad-channel spin exchange relaxation-free magnetometer 被引量:5
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作者 Peng-Cheng Du Jian-Jun Li +4 位作者 Si-Jia Yang Xu-Tong Wang Yan Zhuo Fan Wang Ru-Quan Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第4期141-144,共4页
We observed the steady-state visually evoked potential(SSVEP) from a healthy subject using a compact quad-channel potassium spin exchange relaxation-free(SERF) optically pumped magnetometer(OPM). To this end, 30 s of ... We observed the steady-state visually evoked potential(SSVEP) from a healthy subject using a compact quad-channel potassium spin exchange relaxation-free(SERF) optically pumped magnetometer(OPM). To this end, 30 s of data were collected, and SSVEP-related magnetic responses with signal intensity ranging from 150 fT to 300 f T were observed for all four channels. The corresponding signal to noise ratio(SNR) was in the range of 3.5–5.5. We then used different channels to operate the sensor as a gradiometer. In the specific case of detecting SSVEP, we noticed that the short channel separation distance led to a strongly diminished gradiometer signal. Although not optimal for the case of SSVEP detection, this set-up can prove to be highly useful for other magnetoencephalography(MEG) paradigms that require good noise cancellation.Considering its compactness, low cost, and good performance, the K-SERF sensor has great potential for biomagnetic field measurements and brain-computer interfaces(BCI). 展开更多
关键词 optically pumped MAGNETOMETERS steady-state visually EVOKED potentials MAGNETOENCEPHALOGRAPHY
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