期刊文献+
共找到746篇文章
< 1 2 38 >
每页显示 20 50 100
The fitting of a dipolar magnetic field by a dipole model
1
作者 ZhaoJin Rong Yong Wei +8 位作者 Fei He Lucy Klinger YanYan Yang JiaWei Gao Zhen Shi HuaPei Wang ShuHui Cai HuaFeng Qin RiXiang Zhu 《Earth and Planetary Physics》 2025年第6期1125-1134,共10页
Many planets,including the Earth,possess a global dipolar magnetic field.To diagnose the interior source of the dipolar field,researchers usually adopt a dipole model consisting of six parameters to fit the observed d... Many planets,including the Earth,possess a global dipolar magnetic field.To diagnose the interior source of the dipolar field,researchers usually adopt a dipole model consisting of six parameters to fit the observed dataset of the magnetic field.However,the simultaneous fitting of these parameters often leads to multiple local optimal parameter sets.To address this fitting dilemma,Rong ZJ et al.(2021)recently developed a current loop model.This technique can successively separate and invert the loop parameters.Here,we further show how this technique can be reduced and modified to fit a dipole model.Applications of this reduced technique to the International Geomagnetic Reference Field model and the Martian crustal field model highlight its unique ability to diagnose both the planetary global dipolar field and the local crustal field anomaly,a capability that sets it apart from existing methods.The potential impact of this technique on geomagnetism and planetary magnetism is significant,given its unique ability to diagnose both the planetary global dipolar field and the local crustal field anomaly. 展开更多
关键词 geomagnetic field magnetic dipole INVERSION dipolar magnetic field magnetic anomaly crustal magnetic field magnetic sources eccentic dipole
在线阅读 下载PDF
The lifespan mechanism of dipole eddies to the east of Vietnam and their intrinsic connections
2
作者 Yang JIN Meibing JIN +1 位作者 Changming DONG Dongxiao WANG 《Journal of Oceanology and Limnology》 2025年第5期1375-1388,共14页
A cyclonic eddy(CE)is often accompanied by an anticyclonic eddy(AE)to the east of Vietnam in the South China Sea(SCS)in summer,but the dipole lifetime and the intrinsic connection between CE and AE are still understud... A cyclonic eddy(CE)is often accompanied by an anticyclonic eddy(AE)to the east of Vietnam in the South China Sea(SCS)in summer,but the dipole lifetime and the intrinsic connection between CE and AE are still understudied.Data from 1993-2021 reveal that the dipole lifetime are significantly correlated with the wind direction and speed in the dipole region.Higher wind speed was found to be associated with more eastward wind direction and tends to longer dipole lifetime.The wind stress work(WW)on the eddy is much stronger in the eastward jet region than in the CE and AE regions.Comparing of results of 12 higher and lower wind speed years reveal that higher wind can produce stronger mean current,WW and barotropic instability(T4)that further enhances eddy kinetic energy(EKE)and dipole lifetime.The correlations between the dipole CE and AE characteristics are insignificant on interannual scales and mostly insignificant on seasonal scales in the surface layer but significant on seasonal scales in the subsurface layers.In addition,the daily mean vertical profiles(0-500 m)of EKE,vorticity and total deformation rate(TD)between CE and AE remain significantly correlated throughout the dipole’s lifetime,which can be a useful criterion for judging if two eddies are a dipole. 展开更多
关键词 South China Sea(SCS) dipole eddy dipole lifetime wind stress work
在线阅读 下载PDF
Defect Dipole Thermal-stability to the Electro-mechanical Properties of Fe Doped PZT Ceramics
3
作者 SUN Yuxuan WANG Zheng +5 位作者 SHI Xue SHI Ying DU Wentong MAN Zhenyong ZHENG Liaoying LI Guorong 《无机材料学报》 北大核心 2025年第5期545-551,I0009-I0010,共9页
The accepted doping ion in Ti^(4+)-site of PbZr_(y)Ti_(1–y)O_(3)(PZT)-based piezoelectric ceramics is a well-known method to increase mechanical quality factor(Q_(m)),since the acceptor coupled by oxygen vacancy beco... The accepted doping ion in Ti^(4+)-site of PbZr_(y)Ti_(1–y)O_(3)(PZT)-based piezoelectric ceramics is a well-known method to increase mechanical quality factor(Q_(m)),since the acceptor coupled by oxygen vacancy becomes defect dipole,which prevents the domain rotation.In this field,a serious problem is that generally,Qm decreases as the temperature(T)increases,since the oxygen vacancies are decoupled from the defect dipoles.In this work,Q_(m) of Pb_(0.95)Sr_(0.05)(Zr_(0.53)Ti_(0.47))O_(3)(PSZT)ceramics doped by 0.40%Fe_(2)O_(3)(in mole)abnormally increases as T increases,of which the Qm and piezoelectric coefficient(d_(33))at room temperature and Curie temperature(TC)are 507,292 pC/N,and 345℃,respectively.The maximum Qm of 824 was achieved in the range of 120–160℃,which is 62.52%higher than that at room temperature,while the dynamic piezoelectric constant(d_(31))was just slightly decreased by 3.85%.X-ray diffraction(XRD)and piezoresponse force microscopy results show that the interplanar spacing and the fine domains form as temperature increases,and the thermally stimulated depolarization current shows that the defect dipoles are stable even the temperature up to 240℃.It can be deduced that the aggregation of oxygen vacancies near the fine domains and defect dipole can be stable up to 240℃,which pins domain rotation,resulting in the enhanced Q_(m) with the increasing temperature.These results give a potential path to design high Q_(m) at high temperature. 展开更多
关键词 defect dipole temperature characteristic oxygen vacancy electro-mechanical property mechanical quality factor hardening doping
在线阅读 下载PDF
Duality and stability analysis of biomagnetic fluid flow and heat transfer with magnetic particles along a shrinking cylinder in presence of magnetic dipole
4
作者 Jahangir Alam M.G.Murtaza +1 位作者 Efstratios Tzirtzilakis Mohammad Ferdows 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期581-601,共21页
In the present study,we concentrate on finding the dual solutions of biomagnetic fluid namely blood flow and heat transfer along with magnetic particles over a two dimensional shrinking cylinder in the presence of a m... In the present study,we concentrate on finding the dual solutions of biomagnetic fluid namely blood flow and heat transfer along with magnetic particles over a two dimensional shrinking cylinder in the presence of a magnetic dipole.To make the results physically realistic,stability analysis is also carried out in this study so that we realized which solution is stable and which is not.The governing partial equations are converted into ordinary differential equations by using similarity transformations and the numerical solution is calculated by applying bvp4c function technique in MATLAB software.The effects of different physical parameters are plotted graphically and discussed according to the outcomes of results.From the present study we observe that ferromagnetic interaction parameter had a great influenced on fluid velocity and temperature distributions.It is also found from the current analysis that the first and second solutions of shrinking cylinder obtained only when we applied particular ranges values of suction parameter.The most important characteristics part of study is to analyze the skin friction coefficient and rate of heat transfer which also covered in this analysis.It reveals that both skin friction coefficient and rate of heat transfer are reduced with rising values of ferromagnetic number.A comparison has also been made to make the solution feasible. 展开更多
关键词 dual solutions stability analysis biomagnetic fluid BLOOD magnetic particles shrinking cylinder magnetic dipole
在线阅读 下载PDF
Tuning intramolecular dipole interactions in dinuclear single-molecule magnetic complexes of Er(Ⅲ)with monosubstituted cyclooctatetraenide ligands
5
作者 Qiwei Chen Yousong Ding +2 位作者 Xiaofei Zhu Bingwu Wang Zhiping Zheng 《Journal of Rare Earths》 2025年第6期1213-1219,I0005,共8页
Manipulating magnetic couplings in molecular magnets is of great importance in improving the mag-netic properties of such materials.It has been proved that by adjusting the strength of magnetic cou-plings and the arra... Manipulating magnetic couplings in molecular magnets is of great importance in improving the mag-netic properties of such materials.It has been proved that by adjusting the strength of magnetic cou-plings and the arrangement of the intermolecular magnetic dipoles,magnetic blocking can be significantly enhanced.Herein manipulating the intramolecular dipole interactions by ligand modifica-tion was attempted with the use of three closely related dinuclear Er(Ⅲ)complexes of a common chemical formula of[(COT^(R))Er(μ-CI)(THF)]_(2)(COT^(R)is monosubstituted cyclooctatetraenide dianions with R=diphenylmethylsilyl(Ph_(2)MeS)for 1,triethylsilyl(TES)for 2,and triisopropylsilyl(TIPS)for 3).Each of these complexes features a centrosymmetric dinuclear core unit with their component Er(Ⅲ)ions doubly bridged by two chloro ligands and further coordinated with a capping substituted corR ligand and a coordinated THF molecule.Magnetic studies reveal that the complexes display similar ferromagnetic couplings with comparable single-molecule magnetic behaviors.The ferromagnetic couplings dominated by the intramolecular dipole interactions are found to be 0.7614,0.7380,and 0.5635 cm^(-1)for 1,2,and 3,respectively.The angles(θ)between the magnetic easy axes and the intramolecular Er-Er lines are 24.88(2)°,25.23(1),and 31.85(5),leading to transversal dipole fields of 0.0114,0.0113,and 0.0125 T for 1,2,and 3,respectively.Although the different ligand substitution generates a sizable difference of about 7 in theθangle,the resulting difference in the dipole interactions is not sufficiently strong to cause any significant differences in their magnetic properties.Further change in theθangles to the"side-by-side"(θ=90°)or"head-to-tail"(θ=0°)arrangement of the magnetic easy axes,achievable by rational mo-lecular design,is expected to lead to molecular magnetic materials with much enhanced properties. 展开更多
关键词 Single-molecule magnet dipole interaction Cyclooctatetraenide dianion Magnetic easy axe Ferromagnetic coupling RAREEARTHS
原文传递
Interannual variability of short rains in Tanzania and the influences from ENSO and the Indian Ocean Dipole
6
作者 Issa Rwambo Yi Fan +3 位作者 Peilong Yu Changyu Chu Matthews Nyasulu Philemon King'uza 《Atmospheric and Oceanic Science Letters》 2025年第6期43-48,共6页
Tanzania is mainly subject to a bimodal rainfall pattern,characterized by two distinct seasons:the long rains,occurring from March to May,and the short rains,which typically take place from October to December(OND).Sh... Tanzania is mainly subject to a bimodal rainfall pattern,characterized by two distinct seasons:the long rains,occurring from March to May,and the short rains,which typically take place from October to December(OND).Short rains are usually less intense but still significantly influence local agriculture.Therefore,with station-based observations and reanalysis data,the current paper examines the interannual variability of OND precipitation in Tanzania from 1993 to 2022 and explores the possible impacts from El Niño–Southern Oscillation(ENSO)and the Indian Ocean Dipole(IOD)as well as the mechanisms.It is found that the Tanzania OND precipitation is above(below)normal in 1997,2006,2011,and 2019(1993,1998,2005,and 2016).The composite difference between wet(dry)years and the climatology indicates that the anomalous lower-level convergence(divergence)and upward(downward)motion are the critical circulation characters for above(below)precipitation.Further analysis indicates ENSO and the IOD are the two main oceanic systems modulating OND precipitation in Tanzania.El Niño and a positive IOD could induce easterly anomalies and weaken the Walker circulation over the Indian Ocean,consequently leading to lower-level convergence in water vapor flux,upward anomalies,and more than normal precipitation in Tanzania.In contrast,La Niña and a negative IOD produce opposite circulation anomalies and less than normal precipitation over Tanzania.Moreover,through partial correlation and Generalized Equilibrium Feedback Analysis,the individual contributions of ENSO and the IOD to circulation are investigated.It is found that although both the IOD and ENSO impact the Walker circulation,the feedback to the IOD is stronger than ENSO.These results provide critical insights into the oceanic drivers and their mechanistic pathways underlying precipitation anomalies in Tanzania. 展开更多
关键词 ENSO Indian ocean dipole Tanzania PRECIPITATION Generalized equilibrium feedback assessment
在线阅读 下载PDF
Color dipole cross-section from unifying the color-dipole picture and improved saturation models
7
作者 G R Boroun 《Communications in Theoretical Physics》 2025年第5期60-67,共8页
We present an analysis of the color-dipole picture for determination of the gluon density at low-x which is obtained from the Altarelli-Martinelli equation by expansion at distinct points of expansion.The dipole cross... We present an analysis of the color-dipole picture for determination of the gluon density at low-x which is obtained from the Altarelli-Martinelli equation by expansion at distinct points of expansion.The dipole cross-sections with respect to the improved saturation model of Bartels–Golec-Biernat–Kowalski are obtained in a wide range of transverse sizes r and compared with the Golec-Biernat-Ẅu sthoff model.We find that the model gives a good description of the dipole cross-section at large r which confirms saturation and matches the perturbative QCD result at a small r due to the significant role of the running of the gluon distribution. 展开更多
关键词 color dipole model SATURATION gluon density LOW-X
原文传递
Intermediate-motivated charge transfer via alternate dipoles accelerating the deep redox of iodine/sulfur/molybdenum for high-performance multiple ion batteries
8
作者 Chao Chen Ruijie Li Yun Gong 《Journal of Energy Chemistry》 2025年第5期297-311,共15页
Sodium-sulfur and sodium-iodine batteries are attractive due to their low cost and high capacities.However,they suffer from polysulfide/polyiodide dissolution and fast capacity decay.To solve these issues,herein,an or... Sodium-sulfur and sodium-iodine batteries are attractive due to their low cost and high capacities.However,they suffer from polysulfide/polyiodide dissolution and fast capacity decay.To solve these issues,herein,an organic species-intercalated layered MoS_(2) with oxygen-dopant(Org-MoS_(2)) was designed for the iodine encapsulation.The chemically-bonded S^(2-) from the S-Mo-S layer can not only stabilize the in situ generated I^(+) intermediate to boost the redox kinetics and deep transformations of 2I^(-)←→I_(2)←→2I^(+),but also undergo the conversion of S^(2-)←→S^(δ-) in the high voltage range of 1.5-3.4 V without structural collapse and shuttle effect.That is owning to the I^(+)-induced local charge and the electron reservoir of multi-valent Mo,which facilitate effective charge transfer via alternate dipoles of I^(δ+)-^(δ-)S^(δ+)/^(δ-)O^(δ+)-^(δ-)Mo^(δ+)-^(δ-)S^(δ+) and promote the redox of I/S/Mo.Meanwhile,the incorporated organic species are transformed into an aromatic carbonaceous material with improved electron conductivity and thinner thickness in the cycling test accompanied by the exposure of more Mo-O-Mo linkages,resulting in an increasing ultrahigh capacity and outstanding long-term durability of Org-MoS_(2)@I_(2). 展开更多
关键词 INTERMEDIATE Alternate dipole Organic species-intercalated MoS_(2) Oxygen-doping Na-I_(2)battery
在线阅读 下载PDF
Accelerating lithium ion conduction via activated interfacial dipole layer for long-life and high-voltage solid-state lithium-metal battery
9
作者 Lv Xu Meng Yao +7 位作者 Liyu Du Yong Chen Yanqiang Wei Du Yuan Hao Wu Haitao Zhang Yun Zhang Guoxiu Wang 《Journal of Energy Chemistry》 2025年第9期92-100,I0004,共10页
The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SL... The absence of efficient ion transport pathways in composite solid-state electrolytes(CSEs)usually results in low ionic conductivity,which remains a great challenge for developing solid-state lithiummetal batteries(SLMBs).Herein,we report achieving accelerated Li^(+)conduction in CSEs by a novel activation of the interfacial dipole layer.Polycationic ionic liquids and polyacrylonitrile with highly polar functional groups(-C≡N)are utilized to modulate the interfacial dipole layer in MOF-based CSEs,facilitating long-range pathways for the connectivity of Li^(+)conduction and enhancing rapid transport kinetics.The as-synthesized CSEs exhibit a high ionic conductivity of 0.59 mS cm^(-1)and a lithium transfer number of 0.85.The assembled SLMBs(Li/CSE/LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2))delivered a high-capacity retention of 88.7%with a minimal discharge voltage attenuation of 17.1 mV after 500 cycles(0.03 mV per cycle)at0.5 C.This work offers an effective approach to creating interpenetrating lithium-ion transport pathways with rapid ion transport kinetics for solid-state electrolytes,thereby advancing the development of solidstate lithium metal batteries. 展开更多
关键词 Interfacial dipole layer High-voltage lithium-metal battery Composite solid electrolyte Lithium-ion conduction channels
在线阅读 下载PDF
ELLIPTIC EQUATION WITH CRITICAL EXPONENT AND DIPOLE POTENTIAL: EXISTENCE AND DECAY ESTIMATES
10
作者 Yu SU Zhisu LIU Senli LIU 《Acta Mathematica Scientia》 2025年第2期636-658,共23页
The paper is concerned with a class of elliptic equation with critical exponent and Dipole potential.More precisely,we make use of the refined Sobolev inequality with Morrey norm to obtain the existence and decay prop... The paper is concerned with a class of elliptic equation with critical exponent and Dipole potential.More precisely,we make use of the refined Sobolev inequality with Morrey norm to obtain the existence and decay properties of nonnegative radial ground state solutions. 展开更多
关键词 dipole potential decay estimation Hardy Sobolev critical exponent Henon Sobolev critical exponent
在线阅读 下载PDF
Density distribution of ground state of one-dimensional Bose gas with dipole interaction
11
作者 Shuchang Hao Yajiang Hao 《Chinese Physics B》 2025年第3期245-249,共5页
Using the Bose-Fermi mapping method,we obtain the exact ground state wavefunction of one-dimensional(1D)Bose gas with the zero-range dipolar interaction in the strongly repulsive contact interaction limit.Its ground s... Using the Bose-Fermi mapping method,we obtain the exact ground state wavefunction of one-dimensional(1D)Bose gas with the zero-range dipolar interaction in the strongly repulsive contact interaction limit.Its ground state density distributions for both repulsive and attractive dipole interactions are exhibited.It is shown that in the case of the finite dipole interaction the density profiles do not change obviously with the increase of dipole interaction and display the typical shell structure of Tonks-Girardeau gases.As the repulsive dipole interaction is greatly strong,the density decreases at the center of the trap and displays a sunken valley.As the attractive dipole interaction increases,the density displays more oscillations and sharp peaks appear in the strong attraction limit,which mainly originate from the atoms occupying the low single particle levels. 展开更多
关键词 Bose gas ONE-DIMENSIONAL dipole interaction
原文传递
Impact of the Winter Southern Indian Ocean Dipole on the Summer Precipitation Pattern of Southern Flood and Northern Drought in China
12
作者 KAN Zi-tong ZHAO Liang +3 位作者 LI Qing-quan SHEN Xin-yong DING Yi-hui LIU Yan-ju 《Journal of Tropical Meteorology》 2025年第3期257-270,共14页
This study explores the impact of winter sea surface temperature(SST)anomalies in the Southern Indian Ocean on summer precipitation patterns in China,utilizing data from reanalysis sources and Coupled Model Intercompa... This study explores the impact of winter sea surface temperature(SST)anomalies in the Southern Indian Ocean on summer precipitation patterns in China,utilizing data from reanalysis sources and Coupled Model Intercomparison Project Phase 6(CMIP6)models.The results reveal that the Southern Indian Ocean Dipole(SIOD),characterized by contrasting SST anomalies in the northeast and southwest regions,acts as a predictor for Chinese summer precipitation patterns,namely floods in the south and drought in the north.In a positive SIOD event,the southwestern Indian Ocean exhibits warmer SSTs,while the northeastern region remains cooler.A negative SIOD event shows the opposite pattern.During the positive phase of the SIOD,the winter SST distribution strengthens the 850-hPa cross-equatorial airflow,generating a robust low-level westerly jet that enhances water vapor transport to the Bay of Bengal(BoB).These air-sea interactions maintain lower SSTs in the northeastern region,which significantly increase the land-sea temperature contrast in the Northern Hemisphere during spring and summer.This strengthened thermal gradient intensifies the southwest monsoon,establishing a strong convergence zone near the South China Sea and amplifying monsoon-driven precipitation in South China.Additionally,CMIP6 models,such as NorESM2-LM and NorCPM1,which accurately simulate the SIOD pattern,effectively capture the seasonal response of cross-equatorial airflow driven by SST anomalies of Southern Indian Ocean.The result highlights the essential role of cross-equatorial airflow generated by the SIOD in forecasting crossseasonal precipitation patterns. 展开更多
关键词 Southern Indian Ocean dipole cross-equatorial airflow summer precipitation pattern in China South China Sea monsoon CMIP6
在线阅读 下载PDF
Asymmetric ruthenium-iron dipole enabling fast alkaline water splitting on ruthenium-doped iron-nickel layered double hydroxides
13
作者 Jiayang Li Gaowa Naren +7 位作者 Chunmei Tang Lixin Xing Ling Meng Ning Wang Ruiming Zhang Siyu Ye Liguang Wang Lei Du 《Materials Reports(Energy)》 2025年第3期87-94,共8页
Electrically driven water splitting is an efficient method for green hydrogen production;however,its practical application is substantially constrained by the kinetically sluggish anodic oxygen evolution reaction(OER)... Electrically driven water splitting is an efficient method for green hydrogen production;however,its practical application is substantially constrained by the kinetically sluggish anodic oxygen evolution reaction(OER).Ruthenium(Ru)and its oxides are widely recognized as highly active OER catalysts.Although Ru is significantly cheaper than iridium(Ir),further reducing its content remains desirable.Herein,atomically dispersed Ru is doped into iron-nickel layered double hydroxides(Ru-FeNi-LDH)to decrease the Ru usage.We found that the Ru doping limit is roughly 9 wt%,and the Ru doping content significantly alters the OER kinetics-note that the high Ru concentration remarkably damages the Ru-FeNi-LDH structure and leads to agglomeration formation.By optimizing the Ru doping content to 3.3 wt%,the Ru-FeNi-LDH presents a low overpotential of 230 mV to reach a current density of 10 mA cm^(-2) in 1 M KOH,which is far better than the reference FeNi-LDH(280 mV)and RuO_(2)(350 mV).In the overall water splitting test,the current density of 10 mA cm^(-2) can be reached at a low voltage of 1.52 V,with stable operation for 80 h.Interestingly,Ru and Fe form an asymmetric Ru-Fe dipole,which is likely doped together into the LDH because the content of Fe instead of Ni is dependent on Ru content in experimental results.The electron-deficient feature of the Ru-Fe dipole thus facilitates the OER process.This work demonstrates a dual-transition metal synergy,providing a design strategy for OER and related catalysts. 展开更多
关键词 Alkaline water splitting Oxygen evolution reaction(OER) Ruthenium-iron dipole Ruthenium-doped iron-nickel layered double hydroxides
在线阅读 下载PDF
Numerical Analysis of the Magnetic Dipole Effect on a Radiative Ferromagnetic Liquid Flowing over a Porous Stretched Sheet 被引量:5
14
作者 G.Dharmaiah F.Mebarek-Oudina +1 位作者 K.S.Balamurugan N.Vedavathi 《Fluid Dynamics & Materials Processing》 EI 2024年第2期293-310,共18页
The effects of a magnetic dipole on a nonlinear thermally radiative ferromagnetic liquidflowing over a stretched surface in the presence of Brownian motion and thermophoresis are investigated.By means of a similarity t... The effects of a magnetic dipole on a nonlinear thermally radiative ferromagnetic liquidflowing over a stretched surface in the presence of Brownian motion and thermophoresis are investigated.By means of a similarity transformation,ordinary differential equations are derived and solved afterwards using a numerical(the BVP4C)method.The impact of various parameters,namely the velocity,temperature,concentration,is presented graphically.It is shown that the nanoparticles properties,in conjunction with the magnetic dipole effect,can increase the thermal conductivity of the engineered nanofluid and,consequently,the heat transfer.Comparison with earlier studies indicates high accuracy and effectiveness of the numerical approach.An increase in the Brow-nian motion parameter and thermophoresis parameter enhances the concentration and the related boundary layer.The skin-friction rises when the viscosity parameter is increased.A larger value of the ferromagnetic para-meter results in a higher skin-friction and,vice versa,in a smaller Nusselt number. 展开更多
关键词 Brownian motion thermo-phoresis radiation magnetic dipole BVP4C NON-LINEAR
在线阅读 下载PDF
Terahertz toroidal dipole metamaterial sensors for detection of aflatoxin B1
15
作者 徐建伟 欧阳收剑 +4 位作者 段守鑫 邹林儿 叶丹妮 杨思嘉 邓晓华 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期672-676,共5页
Terahertz metamaterial biosensors have attracted significant attention in the biological field due to their advantages of label-free,real-time and in situ detection.In this paper,a highly sensitive metamaterial sensor... Terahertz metamaterial biosensors have attracted significant attention in the biological field due to their advantages of label-free,real-time and in situ detection.In this paper,a highly sensitive metamaterial sensor with semi-ring mirror symmetry based on toroidal dipole resonance is designed for a new metamaterial biosensor.It is shown that a refractive index sensitivity of 337.5 GHz per refractive index unit can be achieved under an analyte of saturated thickness near a 1.33 THz transmission dip.For biosensor samples where aflatoxin B1 is dropped on the metamaterial surface in our experiment,dip amplitudes of transmission varying from 0.1904 to 0.203 and 0.2093 are observed as aflatoxin B1 concentrations are altered from 0 to 0.001μg·ml-1 and to 0.01μg·ml-1,respectively.Furthermore,when aflatoxin B1 concentrations are 0.1μg·ml-1,1μg·ml-1,10μg·ml-1 and 100μg·ml-1,dip amplitudes of 0.2179,0.226,0.2384 and 0.2527 and dip redshifts of 10.1 GHz,20.1 GHz,27.7 GHz and 37.6 GHz are respectively observed.These results illustrate high-sensitivity,label-free detection of aflatoxin B1,enriching the applications of sensors in the terahertz domain. 展开更多
关键词 TERAHERTZ METAMATERIAL toroidal dipole aflatoxin B1
原文传递
Dipole polarization modulating of vinylene-linked covalent organic frameworks for efficient photocatalytic hydrogen evolution
16
作者 Ming Wang Yaling Li +6 位作者 Dengxin Yan Hui Hu a Yujie Song Xiaofang Su Jiamin Sun Songtao Xiao Yanan Gao 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第10期103-112,共10页
Photocatalytic hydrogen(H_(2))evolution using covalent organic frameworks(COFs)is an attractive and promising avenue for exploration,but one of its big challenges is low photo-induced charge separation.In this study,w... Photocatalytic hydrogen(H_(2))evolution using covalent organic frameworks(COFs)is an attractive and promising avenue for exploration,but one of its big challenges is low photo-induced charge separation.In this study,we present a straightforward and facile dipole polarization engineering strategy to enhance charge separation efficiency,achieved through atomic modulation(O,S,and Se)of the COF monomer.Our findings demonstrate that incorporating atoms with varying electronegativities into the COF matrix significantly influences the local dipole moment,thereby affecting charge separation efficiency and photostability,which in turn affects the rates of photocatalytic H_(2) evolution.As a result,the newly developed TMT-BO-COF,which contains highly electronegative O atoms,exhibits the lowest exciton binding energy,the highest efficiency in charge separation and transportation,and the longest lifetime of the active charges.This leads to an impressive average H_(2) production rate of 23.7 mmol g^(−1) h^(−1),which is 2.5 and 24.5 times higher than that of TMT-BS-COF(containing S atoms)and TMT-BSe-COF(containing Se atoms),respectively.A novel photocatalytic hydrogen evolution mechanism based on proton-coupled electron transfer on N in the structure of triazine rings in vinylene-linked COFs is proposed by theoretical calculations.Our findings provide new insights into the design of highly photoactive organic framework materials for H_(2) evolution and beyond. 展开更多
关键词 Covalent organic framework Vinylene linkage ELECTRONEGATIVITY dipole polarization Photocatalytic hydrogen evolution
在线阅读 下载PDF
Enhancing Defect-Induced Dipole Polarization Strategy of SiC@MoO_(3)Nanocomposite Towards Electromagnetic Wave Absorption
17
作者 Ting Wang Wenxin Zhao +8 位作者 Yukun Miao Anguo Cui Chuanhui Gao Chang Wang Liying Yuan Zhongning Tian Alan Meng Zhenjiang Li Meng Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第12期406-426,共21页
Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic stru... Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic structures of the materials.However,achieving a comprehensive understanding of the relationship between micro-structures and electromagnetic wave absorption capabilities remains elusive,posing a substantial challenge to the advancement of TMOs absorbers.The current research describes a process for the deposition of a MoO_(3)layer onto SiC nanowires,achieved via electro-deposition followed by high-temperature calcination.Subsequently,intentional creation of oxygen vacancies within the MoO_(3)layer was carried out,facilitating the precise adjustment of electromagnetic properties to enhance the microwave absorption performance of the material.Remarkably,the SiC@MO-t4 sample exhibited an excellent minimum reflection loss of-50.49 dB at a matching thickness of 1.27 mm.Furthermore,the SiC@MO-t6 sample exhibited an effective absorption bandwidth of 8.72 GHz with a thickness of 2.81 mm,comprehensively covering the entire Ku band.These results not only highlight the pivotal role of defect engineering in the nuanced adjustment of electromagnetic properties but also provide valuable insight for the application of defect engineering methods in broadening the spectrum of electromagnetic wave absor ption effectiveness.SiC@MO-t samples with varying concentrations of oxygen vacancies were prepared through in-situ etching of the SiC@MoO_(3)nanocomposite.The presence of oxygen vacancies plays a crucial role in adjusting the band gap and local electron distribution,which in turn enhances conductivity loss and induced polarization loss capacity.This finding reveals a novel strategy for improving the absorption properties of electromagnetic waves through defect engineering. 展开更多
关键词 Defect engineering Oxygen vacancies SiC@MoO_(3)nanocomposite Electromagnetic wave absorption Induced dipole polarization
在线阅读 下载PDF
Characteristics and triggering mechanisms of early negative Indian Ocean Dipole
18
作者 Yue Fang Shuangwen Sun +2 位作者 Yongcan Zu Jianhu Wang Lin Feng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期59-65,共7页
Negative Indian Ocean Dipole(nIOD)can exert great impacts on global climate and can also strongly influence the climate in China.Early nIOD is a major type of nIOD,which can induce more pronounced climate anomalies in... Negative Indian Ocean Dipole(nIOD)can exert great impacts on global climate and can also strongly influence the climate in China.Early nIOD is a major type of nIOD,which can induce more pronounced climate anomalies in summer than La Niña-related nIOD.However,the characteristics and triggering mechanisms of early nIOD are unclear.Our results based on reanalysis datasets indicate that the early nIOD and La Niña-related nIOD are the two major types of nIOD,and the former accounts for over one third of all the nIOD events in the past six decades.These two types of nIODs are similar in their intensities,but are different in their spatial patterns and seasonal cycles.The early nIOD,which develops in spring and peaks in summer,is one season earlier than the La Niña-related nIOD.The spatial pattern of the wind anomaly associated with early nIOD exhibits a winter monsoon-like pattern,with strong westerly anomalies in the equatorial Indian Ocean and eastly anomalies in the northern Indian Ocean.Opposite to the triggering mechanism of early positve IOD,the early nIOD is induced by delayed Indian summer monsoon onset.The results of this study are helpful for improving the prediction skill of IOD and its climate impacts. 展开更多
关键词 Indian Ocean dipole(IOD) triggering mechanism Indian summer monsoon seasonal cycle negative IOD
在线阅读 下载PDF
Impact of a Magnetic Dipole on Heat Transfer in Non-Conducting Magnetic Fluid Flow over a Stretching Cylinder
19
作者 Anupam Bhandari 《Fluid Dynamics & Materials Processing》 EI 2024年第3期475-486,共12页
The thermal behavior of an electrically non-conducting magnetic liquid flowing over a stretching cylinder under the influence of a magnetic dipole is considered.The governing nonlinear differential equations are solve... The thermal behavior of an electrically non-conducting magnetic liquid flowing over a stretching cylinder under the influence of a magnetic dipole is considered.The governing nonlinear differential equations are solved numerically using a finite element approach,which is properly validated through comparison with earlier results available in the literature.The results for the velocity and temperature fields are provided for different values of the Reynolds number,ferromagnetic response number,Prandtl number,and viscous dissipation parameter.The influence of some physical parameters on skin friction and heat transfer on the walls of the cylinder is also investigated.The applicability of this research to heat control in electronic devices is discussed to a certain extent. 展开更多
关键词 FERROFLUID stretching cylinder finite element method heat transfer magnetic dipole
在线阅读 下载PDF
Theoretical investigation of excited dipole bound states of alkali-containing diatomic anions
20
作者 连艺 肖利丹 +2 位作者 边丽丽 徐海峰 闫冰 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期389-393,共5页
Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic st... Information about electronic excited states of molecular anions plays an important role in investigating electron attachment and detachment processes.Here we present a high-level theoretical study of the electronic structures of 12 alkali-metal-containing diatomic anions MX-(MX = LiH,LiF,LiCl,NaF,NaCl,NaBr,RbCl,KCl,KBr,RbI,KI and CsI).The equation-of-motion electron-attachment coupled-cluster singles and doubles(EOM-EA-CCSD) method is used to calculate the electron binding energies(EBEs) of 10 electronic excited states of each of the 12 molecule anions.With addition of different s-/p-/d-type diffusion functions in the basis set,we have identified possible excited dipole bound states(DBSs) of each anion.With the investigation of EBEs on the 12 MXs with dipole moment(DM) up to 12.1 D,we evaluate the dependence of the number of anionic excited DBSs on molecular DM.The results indicate that there are at least two or three DBSs of anions with a molecular DM larger than 7 D and a molecule with DM > 10 D can sustain a π-DBS of the anion.Our study has some implications for the excited DBS electronic states of alkali-metal-containing diatomic molecules. 展开更多
关键词 ANIONS dipole bound states alkali-metal-containing diatomic molecules
原文传递
上一页 1 2 38 下一页 到第
使用帮助 返回顶部