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Resonantly enhanced second-and third-harmonic generation in dielectric nonlinear metasurfaces 被引量:1
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作者 Ji Tong Wang Pavel Tonkaev +5 位作者 Kirill Koshelev Fangxing Lai Sergey Kruk Qinghai Song Yuri Kivshar Nicolae C.Panoiu 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第5期5-19,共15页
Nonlinear dielectric metasurfaces provide a promising approach to control and manipulate frequency conversion optical processes at the nanoscale,thus facilitating both advances in fundamental research and the developm... Nonlinear dielectric metasurfaces provide a promising approach to control and manipulate frequency conversion optical processes at the nanoscale,thus facilitating both advances in fundamental research and the development of new practical applications in photonics,lasing,and sensing.Here,we employ symmetry-broken metasurfaces made of centrosymmetric amorphous silicon for resonantly enhanced second-and third-order nonlinear optical response.Exploiting the rich physics of optical quasi-bound states in the continuum and guided mode resonances,we comprehensively study through rigorous numerical calculations the relative contribution of surface and bulk effects to second-harmonic generation(SHG)and the bulk contribution to third-harmonic generation(THG) from the meta-atoms.Next,we experimentally achieve optical resonances with high quality factors,which greatly boosts light-matter interaction,resulting in about 550 times SHG enhancement and nearly 5000-fold increase of THG.A good agreement between theoretical predictions and experimental measurements is observed.To gain deeper insights into the physics of the investigated nonlinear optical processes,we further numerically study the relation between nonlinear emission and the structural asymmetry of the metasurface and reveal that the generated harmonic signals arising from linear sharp resonances are highly dependent on the asymmetry of the meta-atoms.Our work suggests a fruitful strategy to enhance the harmonic generation and effectively control different orders of harmonics in all-dielectric metasurfaces,enabling the development of efficient active photonic nanodevices. 展开更多
关键词 second-harmonic generation third-harmonic generation bound state in the continuum guided mode resonance all-dielectric metasurfaces nonlinear optics
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Two Distinct Charge Orders in Infinite-Layer PrNiO_(2+δ) Revealed by Resonant X-Ray Diffraction
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作者 Xiaolin Ren Ronny Sutarto +9 位作者 Qiang Gao Qisi Wang Jiarui Li Yao Wang Tao Xiang Jiangping Hu J.Chang Riccardo Comin X.J.Zhou Zhihai Zhu 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第11期154-169,共16页
Research of infinite-layer nickelates has unveiled a broken translation symmetry,which has sparked significant interest in its root,its relationship to superconductivity,and its comparison to charge order in cuprates.... Research of infinite-layer nickelates has unveiled a broken translation symmetry,which has sparked significant interest in its root,its relationship to superconductivity,and its comparison to charge order in cuprates.In this study,resonant x-ray scattering measurements were performed on thin films of infinite-layer PrNiO_(2+δ).The results show significant differences in the superlattice reflection at the Ni L_(3) absorption edge compared to that at the Pr M_(5) resonance in their dependence on energy,temperature,and local symmetry.These differences point to two distinct charge orders,although they share the same in-plane wavevectors.It is suggested that these dissimilarities could be linked to the excess oxygen dopants,given that the resonant reflections were observed in an incompletely reduced PrNiO_(2+δ)film.Furthermore,azimuthal analysis indicates that the oxygen ligands likely play a crucial role in the charge modulation revealed at the Ni L_(3) resonance. 展开更多
关键词 film. resonant CHARGE
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High-Q resonant terahertz metasurfaces
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作者 Manukumara Manjappa Yuri Kivshar 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第4期1-3,共3页
In photonics, the quest for high-quality (high Q) resonances driven by the physics of bound states in the continuum (BIC)1,2has motivated researchers to explore innovative avenues for realizing groundbreaking applicat... In photonics, the quest for high-quality (high Q) resonances driven by the physics of bound states in the continuum (BIC)1,2has motivated researchers to explore innovative avenues for realizing groundbreaking applications in lasing3, sensing4and nonlinear photonics5. A conventional strategy to harness the properties of BICs involves breaking the symmetry of resonators in a uniform lattice, allowing uncoupled modes to interact with free space that opens a leaky channel in the form of socalled (quasi) q BIC6modes. 展开更多
关键词 BREAKING resonant SYMMETRY
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Polariton lasing in Mie-resonant perovskite nanocavity
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作者 Mikhail A.Masharin Daria Khmelevskaia +12 位作者 Valeriy I.Kondratiev Daria I.Markina Anton D.Utyushev Dmitriy M.Dolgintsev Alexey D.Dmitriev Vanik A.Shahnazaryan Anatoly P.Pushkarev Furkan Isik Ivan V.Iorsh Ivan A.Shelykh Hilmi V.Demir Anton K.Samusev Sergey V.Makarov 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第4期27-42,共16页
Deeply subwavelength lasers(or nanolasers)are highly demanded for compact on-chip bioimaging and sensing at the nanoscale.One of the main obstacles for the development of single-particle nanolasers with all three dime... Deeply subwavelength lasers(or nanolasers)are highly demanded for compact on-chip bioimaging and sensing at the nanoscale.One of the main obstacles for the development of single-particle nanolasers with all three dimensions shorter than the emitting wavelength in the visible range is the high lasing thresholds and the resulting overheating.Here we ex-ploit exciton-polariton condensation and mirror-image Mie modes in a cuboid CsPbBr3 nanoparticle to achieve coherent emission at the visible wavelength of around 0.53μm from its ultra-small(≈0.007μm3 or≈λ3/20)semiconductor nanocav-ity.The polaritonic nature of the emission from the nanocavity localized in all three dimensions is proven by direct com-parison with corresponding one-dimensional and two-dimensional waveguiding systems with similar material parameters.Such a deeply subwavelength nanolaser is enabled not only by the high values for exciton binding energy(≈35 meV),re-fractive index(>2.5 at low temperature),and luminescence quantum yield of CsPbBr3,but also by the optimization of po-laritons condensation on the Mie resonances with quality factors improved by the metallic substrate.Moreover,the key parameters for optimal lasing conditions are intermode free spectral range and phonons spectrum in CsPbBr3,which govern polaritons condensation path.Such chemically synthesized colloidal CsPbBr3 nanolasers can be potentially de-posited on arbitrary surfaces,which makes them a versatile tool for integration with various on-chip systems. 展开更多
关键词 nanolaser PEROVSKITE POLARITON Mie resonance EXCITON-POLARITON
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Seismic evaluation of frequency influence and resonant behavior for lead rubber bearing isolated rigid rectangular liquid tanks
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作者 Jyoti Ranjan Barik Kishore Chandra Biswal 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第4期973-994,共22页
The seismic behavior of a partially filled rigid rectangular liquid tank is investigated under short-and longduration ground motions.A finite element model is developed to analyze the liquid domain by using four-noded... The seismic behavior of a partially filled rigid rectangular liquid tank is investigated under short-and longduration ground motions.A finite element model is developed to analyze the liquid domain by using four-noded quadrilateral elements.The competency of the model is verified with the available results.Parametric studies are conducted for the dynamic parameters of the base-isolated tank,using a lead rubber bearing to evaluate the optimum damping and time period of the isolator.The application of base isolation has reduced the total and impulsive hydrodynamic components of pressure by 80 to 90 percent,and base shear by 15 to 95 percent,depending upon the frequency content and duration of the considered earthquakes.The sloshing amplitude of the base-isolated tank is reduced by 18 to 94 percent for most of the short-duration earthquakes,while it is increased by 17 to 60 percent for the majority of the long-duration earthquakes.Furthermore,resonance studies are carried out through a long-duration harmonic excitation to obtain the dynamic behavior of non-isolated and isolated tanks,using a nonlinear sloshing model.The seismic responses of the base-isolated tank are obtained as higher when the excitation frequency matches the fundamental sloshing frequency rather than the isolator frequency. 展开更多
关键词 lead rubber bearing frequency domain resonant inputs long-duration excitation
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Comparison of transport coefficients before and after density pump-out induced by resonant magnetic perturbation using a BOUT++ six-field model on the EAST tokamak
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作者 邓成成 刘子奚 +22 位作者 夏天阳 刘彦君 厉鹏程 龙飞飞 高翔 王守信 李国强 刘海庆 臧庆 李玖瑛 杨康宁 吴茗甫 尹晓宇 李弘 谢锦林 兰涛 毛文哲 刘阿娣 周楚 丁卫星 庄革 刘万东 the EAST Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期111-119,共9页
Many experiments have demonstrated that resonant magnetic perturbation(RMP) can affect the turbulent transport at the edge of the tokamak. Through the Experimental Advanced Superconducting Tokamak(EAST) density modula... Many experiments have demonstrated that resonant magnetic perturbation(RMP) can affect the turbulent transport at the edge of the tokamak. Through the Experimental Advanced Superconducting Tokamak(EAST) density modulation experiment, the particle transport coefficients were calculated using the experimental data, and the result shows that the particle transport coefficients increase with RMP. In this study, the six-field two-fluid model in BOUT++ is used to simulate the transport before and after density pump-out induced by RMP,respectively referred as the case without RMP and the case with RMP. In the linear simulations,the instabilities generally decreases for cases with RMP. In the nonlinear simulation, ELM only appears in the case without RMP. Additionally, the particle transport coefficient was analyzed,and the result shows that the particle transport coefficient becomes larger for the case with RMP,which is consistent with the experimental conclusion. Moreover, its magnitude is comparable to the results calculated from experimental data. 展开更多
关键词 BOUT++ resonant magnetic perturbation(RMP) transport coefficients
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Investigation on the roles of equilibrium toroidal rotation during edge-localized mode mitigated by resonant magnetic perturbations
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作者 董良康 陈少永 +3 位作者 牟茂淋 罗杨 秦晨晨 唐昌建 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第1期16-33,共18页
The effects of equilibrium toroidal rotation during edge-localized mode(ELM)mitigated by resonant magnetic perturbation(RMP)are studied with the experimental equilibria of the EAST tokamak based on the four-field mode... The effects of equilibrium toroidal rotation during edge-localized mode(ELM)mitigated by resonant magnetic perturbation(RMP)are studied with the experimental equilibria of the EAST tokamak based on the four-field model in the BOUT++code.As the two main parameters to determine the toroidal rotation profiles,the rotation shear and magnitudes were separately scanned to investigate their roles in the impact of RMPs on peeling-ballooning(P-B)modes.On one hand,the results show that strong toroidal rotation shear is favorable for the enhancement of the self-generated E×B shearing rate<ω_(E×B)>with RMPs,leading to significant ELM mitigation with RMP in the stronger toroidal rotation shear region.On the other hand,toroidal rotation magnitudes may affect ELM mitigation by changing the penetration of the RMPs,more precisely the resonant components.RMPs can lead to a reduction in the pedestal energy loss by enhancing the multimode coupling in the turbulence transport phase.The shielding effects on RMPs increase with the toroidal rotation magnitude,leading to the enhancement of the multimode coupling with RMPs to be significantly weakened.Hence,the reduction in pedestal energy loss by RMPs decreased with the rotation magnitude.In brief,the results show that toroidal rotation plays a dual role in ELM mitigation with RMP by changing the shielding effects of plasma by rotation magnitude and affecting<ω_(E×B)>by rotation shear.In the high toroidal rotation region,toroidal rotation shear is usually strong and hence plays a dominant role in the influence of RMP on P-B modes,whereas in the low rotation region,toroidal rotation shear is weak and has negligible impact on P-B modes,and the rotation magnitude plays a dominant role in the influence of RMPs on the P-B modes by changing the field penetration.Therefore,the dual role of toroidal rotation leads to stronger ELM mitigation with RMP,which may be achieved both in the low toroidal rotation region and the relatively high rotation region that has strong rotational shear. 展开更多
关键词 edge-localized mode peeling–ballooning modes resonant magnetic perturbation toroidal rotation plasma response TOKAMAK
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基于Self-Attention-BiLSTM网络的西瓜种苗叶片氮磷钾含量高光谱检测方法
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作者 徐胜勇 刘政义 +3 位作者 黄远 曾雨 别之龙 董万静 《农业机械学报》 EI CAS CSCD 北大核心 2024年第8期243-252,共10页
元素含量无损检测技术可以为植物生长发育的环境精准调控提供关键实时数据。以西瓜苗为例,提出了一种基于图谱特征融合的氮磷钾含量深度学习检测方法。首先,使用高光谱仪拍摄西瓜苗叶片的高光谱图像,使用连续流动化学分析仪测定叶片的3... 元素含量无损检测技术可以为植物生长发育的环境精准调控提供关键实时数据。以西瓜苗为例,提出了一种基于图谱特征融合的氮磷钾含量深度学习检测方法。首先,使用高光谱仪拍摄西瓜苗叶片的高光谱图像,使用连续流动化学分析仪测定叶片的3种元素含量。然后,采用基线偏移校正(BOC)叠加高斯平滑滤波(GF)的光谱预处理方法和随机森林算法(RF)建立预测模型,基于竞争性自适应重加权采样(CARS)和连续投影算法(SPA)2种算法初步筛选出特征波长,再综合考虑波长数和建模精度设计了一种最优波长评价方法,将波长数进一步减少到3~4个。最后,提取使用U-Net网络分割的彩色图像颜色和纹理特征,和光谱反射率特征一起作为输入,基于自注意力机制-双向长短时记忆(Self-Attention-BiLSTM)网络构建了3种元素含量的预测模型。实验结果表明,氮磷钾含量预测的R2分别为0.961、0.954、0.958,RMSE分别为0.294%、0.262%、0.196%,实现了很好的建模效果。使用该模型对另2个品种西瓜进行测试,R2超过0.899、RMSE小于0.498%,表明该模型具有很好的泛化性。该高光谱建模方法使用少量波长光谱即实现了高精度检测,在精度和效率上达成了很好的平衡,为后续便携式高光谱检测装备开发奠定了理论基础。 展开更多
关键词 西瓜苗叶片 元素含量 无损检测 自注意力机制 双向长短时记忆网络 高光谱
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Staging liver fibrosis with various diffusion-weighted magnetic resonance imaging models 被引量:1
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作者 Yan-Li Jiang Juan Li +6 位作者 Peng-Fei Zhang Feng-Xian Fan Jie Zou Pin Yang Peng-Fei Wang Shao-Yu Wang Jing Zhang 《World Journal of Gastroenterology》 SCIE CAS 2024年第9期1164-1176,共13页
BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diff... BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one cohort.AIM To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic performances.METHODS This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy participants.All participants underwent multi-b value DWI.The main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and compared.RESULTS CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis stages.The areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was similar.The combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver disease.The combined index of CTRW parameters had the highest AUC. 展开更多
关键词 Liver fibrosis Magnetic resonance imaging Diffusion-weighted magnetic resonance Liver biopsy Significant fibrosis
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Preoperative prediction of perineural invasion of rectal cancer based on a magnetic resonance imaging radiomics model:A dual-center study 被引量:2
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作者 Yan Liu Bai-Jin-Tao Sun +3 位作者 Chuan Zhang Bing Li Xiao-Xuan Yu Yong Du 《World Journal of Gastroenterology》 SCIE CAS 2024年第16期2233-2248,共16页
BACKGROUND Perineural invasion(PNI)has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer(RC).Preoperative prediction of PNI status is helpful for indivi... BACKGROUND Perineural invasion(PNI)has been used as an important pathological indicator and independent prognostic factor for patients with rectal cancer(RC).Preoperative prediction of PNI status is helpful for individualized treatment of RC.Recently,several radiomics studies have been used to predict the PNI status in RC,demonstrating a good predictive effect,but the results lacked generalizability.The preoperative prediction of PNI status is still challenging and needs further study.AIM To establish and validate an optimal radiomics model for predicting PNI status preoperatively in RC patients.METHODS This retrospective study enrolled 244 postoperative patients with pathologically confirmed RC from two independent centers.The patients underwent preoperative high-resolution magnetic resonance imaging(MRI)between May 2019 and August 2022.Quantitative radiomics features were extracted and selected from oblique axial T2-weighted imaging(T2WI)and contrast-enhanced T1WI(T1CE)sequences.The radiomics signatures were constructed using logistic regression analysis and the predictive potential of various sequences was compared(T2WI,T1CE and T2WI+T1CE fusion sequences).A clinical-radiomics(CR)model was established by combining the radiomics features and clinical risk factors.The internal and external validation groups were used to validate the proposed models.The area under the receiver operating characteristic curve(AUC),DeLong test,net reclassification improvement(NRI),integrated discrimination improvement(IDI),calibration curve,and decision curve analysis(DCA)were used to evaluate the model performance.RESULTS Among the radiomics models,the T2WI+T1CE fusion sequences model showed the best predictive performance,in the training and internal validation groups,the AUCs of the fusion sequence model were 0.839[95%confidence interval(CI):0.757-0.921]and 0.787(95%CI:0.650-0.923),which were higher than those of the T2WI and T1CE sequence models.The CR model constructed by combining clinical risk factors had the best predictive performance.In the training and internal and external validation groups,the AUCs of the CR model were 0.889(95%CI:0.824-0.954),0.889(95%CI:0.803-0.976)and 0.894(95%CI:0.814-0.974).Delong test,NRI,and IDI showed that the CR model had significant differences from other models(P<0.05).Calibration curves demonstrated good agreement,and DCA revealed significant benefits of the CR model.CONCLUSION The CR model based on preoperative MRI radiomics features and clinical risk factors can preoperatively predict the PNI status of RC noninvasively,which facilitates individualized treatment of RC patients. 展开更多
关键词 Rectal cancer Perineural invasion Magnetic resonance imaging Radiomics NOMOGRAM
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Resonant Charge Transport Assisted by the Molecular Vibration in Single-Molecule Junction from Time-Domain ab initio Nonadiabatic Molecular Dynamics Simulations
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作者 田韫哲 郑奇靖 赵瑾 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第12期92-97,共6页
Using ab initio nonadiabatic molecular dynamics simulation, we study the time-dependent charge transport dynamics in a single-molecule junction formed by gold(Au) electrodes and a single benzene-1,4-dithiol(BDT)molecu... Using ab initio nonadiabatic molecular dynamics simulation, we study the time-dependent charge transport dynamics in a single-molecule junction formed by gold(Au) electrodes and a single benzene-1,4-dithiol(BDT)molecule. Two different types of charge transport channels are found in the simulation. One is the routine nonresonant charge transfer path, which occurs in several picoseconds. The other is activated when the electronic state of the electrodes and that of the molecule get close in energy, which is referred to as the resonant charge transport. More strikingly, the resonant charge transfer occurs in an ultrafast manner within 100 fs, which notably increases the conductance of the device. Further analysis shows that the resonant charge transport is directly assisted by the B_(2) and A1 molecular vibration modes. Our study provides atomic insights into the time-dependent charge transport dynamics in single-molecule junctions, which is important for designing highly efficient single-molecule devices. 展开更多
关键词 charge resonant Molecular
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Resonant Auger Scattering by Attosecond X-Ray Pulses
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作者 南全伟 王超 +6 位作者 余心悦 赵曦 程勇军 宫毛毛 刘小井 Victor Kimberg 张松斌 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第9期38-42,共5页
As x-ray probe pulses approach the subfemtosecond range,conventional x-ray photoelectron spectroscopy(XPS)is expected to experience a reduction in spectral resolution due to the effects of the pulse broadening.However... As x-ray probe pulses approach the subfemtosecond range,conventional x-ray photoelectron spectroscopy(XPS)is expected to experience a reduction in spectral resolution due to the effects of the pulse broadening.However,in the case of resonant x-ray photoemission,also known as resonant Auger scattering(RAS),the spectroscopic technique maintains spectral resolution when an x-ray pulse is precisely tuned to a core-excited state.We present theoretical simulations of XPS and RAS spectra on a showcased CO molecule using ultrashort x-ray pulses,revealing significantly enhanced resolution in the RAS spectra compared to XPS,even in the subfemtosecond regime.These findings provide a novel perspective on potential utilization of attosecond x-ray pulses,capitalizing on the well-established advantages of detecting electron signals for tracking electronic and molecular dynamics. 展开更多
关键词 DYNAMICS STATE resonant
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Development of a simple two-step lithography fabrication process for resonant tunneling diode using air-bridge technology
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作者 Swagata Samanta Jue Wang Edward Wasige 《Journal of Semiconductors》 EI CAS CSCD 2023年第11期79-82,共4页
This article reports on the development of a simple two-step lithography process for double barrier quantum well(DBQW)InGaAs/AlAs resonant tunneling diode(RTD)on a semi-insulating indium phosphide(InP)substrate using ... This article reports on the development of a simple two-step lithography process for double barrier quantum well(DBQW)InGaAs/AlAs resonant tunneling diode(RTD)on a semi-insulating indium phosphide(InP)substrate using an air-bridge technology.This approach minimizes processing steps,and therefore the processing time as well as the required resources.It is particularly suited for material qualification of new epitaxial layer designs.A DC performance comparison between the proposed process and the conventional process shows approximately the same results.We expect that this novel technique will aid in the recent and continuing rapid advances in RTD technology. 展开更多
关键词 AIR-BRIDGE indium phosphide MICROFABRICATION resonant tunneling diode
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Relaxation of Ne^(1+)1s^(0)2s^(2)2p^(6)np produced by resonant excitation of an ultraintense ultrafast x-ray pulse
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作者 闫杰 刘彦鹏 +4 位作者 侯永 高城 吴建华 曾交龙 袁建民 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期75-79,共5页
The creation and relaxation of double K-hole states 1s^(0)2s^(2)2p^(6)np(n≥3)of Ne^(1+)in the interaction with ultraintense ultrafast x-ray pulses are theoretically investigated.The x-ray photon energies are selected... The creation and relaxation of double K-hole states 1s^(0)2s^(2)2p^(6)np(n≥3)of Ne^(1+)in the interaction with ultraintense ultrafast x-ray pulses are theoretically investigated.The x-ray photon energies are selected so that x-rays first photoionize1s^(22)s^(22)p^(6) of a neon atom to create a single K-hole state of 1s2s^(22)p^(6) of Ne^(1+),which is further excited resonantly to double K-hole states of ls^(0)2s^(2)2p^(6)np(n≥3).A time-dependent rate equation is used to investigate the creation and relaxation processes of 1s^(0)2s^(2)2p^(6)np,where the primary microscopic atomic processes including photoexcitation,spontaneous radiation,photoionization and Auger decay are considered.The calculated Auger electron energy spectra are compared with recent experimental results,which shows good agreement.The relative intensity of Auger electrons is very sensitive to the photon energy and bandwidth of x-ray pulses,which could be used as a diagnostic tool for x-ray free electron laser and atom experiments. 展开更多
关键词 hollow atoms x-ray resonant excitation RELAXATION
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GaAs-based resonant tunneling diode:Device aspects from design,manufacturing,characterization and applications
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作者 Swagata Samanta 《Journal of Semiconductors》 EI CAS CSCD 2023年第10期26-35,共10页
This review article discusses the development of gallium arsenide(GaAs)-based resonant tunneling diodes(RTD)since the 1970s.To the best of my knowledge,this article is the first review of GaAs RTD technology which cov... This review article discusses the development of gallium arsenide(GaAs)-based resonant tunneling diodes(RTD)since the 1970s.To the best of my knowledge,this article is the first review of GaAs RTD technology which covers different epitaxialstructure design,fabrication techniques,and characterizations for various application areas.It is expected that the details presented here will help the readers to gain a perspective on the previous accomplishments,as well as have an outlook on the current trends and future developments in GaAs RTD research. 展开更多
关键词 gallium arsenide MICROFABRICATION resonant tunneling devices
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Magnetic resonance imaging of extraocular rectus muscles abnormalities in acute acquired concomitant esotropia 被引量:1
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作者 Jia-Yu Chen Li-Rong Zhang +5 位作者 Jia-Wen Liu Jie Hao Hui-Xin Li Qiong-Yue Zhang Zhao-Hui Liu Jing Fu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第1期119-125,共7页
AIM:To investigate the difference of medial rectus(MR)and lateral rectus(LR)between acute acquired concomitant esotropia(AACE)and the healthy controls(HCs)detected by magnetic resonance imaging(MRI).METHODS:A case-con... AIM:To investigate the difference of medial rectus(MR)and lateral rectus(LR)between acute acquired concomitant esotropia(AACE)and the healthy controls(HCs)detected by magnetic resonance imaging(MRI).METHODS:A case-control study.Eighteen subjects with AACE and eighteen HCs were enrolled.MRI scanning data were conducted in target-controlled central gaze with a 3-Tesla magnetic resonance scanner.Extraocular muscles(EOMs)were scanned in contiguous image planes 2-mm thick spanning the EOM origins to the globe equator.To form posterior partial volumes(PPVs),the LR and MR cross-sections in the image planes 8,10,12,and 14 mm posterior to the globe were summed and multiplied by the 2-mm slice thickness.The data were classified according to the right eye,left eye,dominant eye,and non-dominant eye,and the differences in mean cross-sectional area,maximum cross-sectional area,and PPVs of the MR and LR muscle in the AACE group and HCs group were compared under the above classifications respectively.RESULTS:There were no significant differences between the two groups of demographic characteristics.The mean cross-sectional area of the LR muscle was significantly greater in the AACE group than that in the HCs group in the non-dominant eyes(P=0.028).The maximum cross-sectional area of the LR muscle both in the dominant and non-dominant eye of the AACE group was significantly greater than the HCs group(P=0.009,P=0.016).For the dominant eye,the PPVs of the LR muscle were significantly greater in the AACE than that in the HCs group(P=0.013),but not in the MR muscle(P=0.698).CONCLUSION:The size and volume of muscles dominant eyes of AACE subjects change significantly to overcome binocular diplopia.The LR muscle become larger to compensate for the enhanced convergence in the AACE. 展开更多
关键词 acute acquired concomitant esotropia magnetic resonance imaging extraocular muscles
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Non-volatile dynamically switchable color display via chalcogenide stepwise cavity resonators 被引量:1
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作者 Kuan Liu Zhenyuan Lin +2 位作者 Bing Han Minghui Hong Tun Cao 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第1期16-27,共12页
High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching... High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components. 展开更多
关键词 TUNABLE color displays Fabry-Pérot cavity resonators color printing chalcogenide materials
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Resonant perfect absorption of molybdenum disulfide beyond the bandgap
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作者 于昊 谢颖 +3 位作者 魏佳辉 张培晴 崔志英 于浩海 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期670-676,共7页
Light absorption and radiation are fundamental processes in optical science and engineering.Materials with perfect absorption properties play an important role in numerous optical applications.Following the meteoric r... Light absorption and radiation are fundamental processes in optical science and engineering.Materials with perfect absorption properties play an important role in numerous optical applications.Following the meteoric rise of MoS_(2)material,global opportunities and challenges coexist due to its extremely weak light-matter interaction capability beyond its energy band.In this work,we designed a kind of sandwich resonance structure and investigated MoS_(2)as a perfect absorber in the infrared spectrum that should be transparent according to the optical band theory.The infrared absorption properties of W or Au/MoS_(2)/Au models at 800 nm-2400 nm were systematic simulated.By optimizing the structural parameters,the resonant wavelength of perfect absorption can be modulated from 830 nm to 1700 nm with angle insensitivity and polar independence.Moreover,we discovered that the bandwidth of absorption exceeding 50%of the W-top model reaches500 nm,while that of the Au-top model is less than 100 nm,indicating that the top metal material has a great influence on the resonance absorption spectrum.Our work provides a practical route for enhancing and manipulating the light-matter interactions of low-dimensional materials beyond their own band gaps,which will be critical in the future design and implementation of optoelectronic devices and systems. 展开更多
关键词 multilayer MoS_(2) Fabry-Perot structure infrared absorption resonance enhancement
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Impact of resonant magnetic perturbation on blob motion and structure using a gas puff imaging diagnostic on the HL-2A tokamak
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作者 袁金榜 许敏 +6 位作者 余羿 袁博达 聂林 季小全 孙腾飞 王傲 李继全 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第9期34-41,共8页
The impact of resonant magnetic perturbation(RMP)on blob motion and structure in the SOL of the HL-2A tokamak is studied using a gas puff imaging diagnostic.Ellipse fitting is applied to study the structure and motion... The impact of resonant magnetic perturbation(RMP)on blob motion and structure in the SOL of the HL-2A tokamak is studied using a gas puff imaging diagnostic.Ellipse fitting is applied to study the structure and motion of blobs quantitatively.The radial locations,amplitudes and scale sizes of blobs are obtained based on the fitted ellipse.Furthermore,based on the measurement of blob location,the radial and poloidal velocities of blobs are calculated.With the application of RMP,the edge poloidal shear flow is significantly weakened and the wave number spectrum changes from quasisymmetric to significantly up-down asymmetric.The application of RMP also causes the detected blob location to be much further into the far scrape-off layer(SOL)and increases the blob amplitude.Blob poloidal velocity in the SOL is slowed.Larger-size and longer-lifetime blobs are observed with RMP.With the application of RMP,stronger-amplitude and larger-size blobs are detected in the far SOL and they may cause a more serious erosion problem to the first wall. 展开更多
关键词 resonance magnetic perturbations blob structure blob motion gas puff imaging
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High-grade pancreatic intraepithelial neoplasia diagnosed based on changes in magnetic resonance cholangiopancreatography findings:A case report 被引量:2
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作者 Nao Furuya Atsushi Yamaguchi +13 位作者 Naohiro Kato Syuhei Sugata Takuro Hamada Takeshi Mizumoto Yuzuru Tamaru Ryusaku Kusunoki Toshio Kuwai Hirotaka Kouno Kazuya Kuraoka Yoshiyuki Shibata Sho Tazuma Takeshi Sudo Hiroshi Kohno Shiro Oka 《World Journal of Clinical Cases》 SCIE 2024年第8期1487-1496,共10页
BACKGROUND High-grade pancreatic intraepithelial neoplasia(PanIN)exhibits no mass and is not detected by any examination modalities.However,it can be diagnosed by pancreatic juice cytology from indirect findings.Most ... BACKGROUND High-grade pancreatic intraepithelial neoplasia(PanIN)exhibits no mass and is not detected by any examination modalities.However,it can be diagnosed by pancreatic juice cytology from indirect findings.Most previous cases were diagnosed based on findings of a focal stricture of the main pancreatic duct(MPD)and caudal MPD dilatation and subsequent pancreatic juice cytology using endoscopic retrograde cholangiopancreatography(ERCP).We experienced a case of high-grade PanIN with an unclear MPD over a 20-mm range,but without caudal MPD dilatation on magnetic resonance cholangiopancreatography(MRCP).CASE SUMMARY A 60-year-old female patient underwent computed tomography for a follow-up of uterine cancer post-excision,which revealed pancreatic cysts.MRCP revealed an unclear MPD of the pancreatic body at a 20-mm length without caudal MPD dilatation.Thus,course observation was performed.After 24 mo,MRCP revealed an increased caudal MPD caliber and a larger pancreatic cyst.We performed ERCP and detected atypical cells suspected of adenocarcinoma by serial pancreatic juice aspiration cytology examination.We performed a distal pancreatectomy and obtained a histopathological diagnosis of high-grade PanIN.Pancreatic parenchyma invasion was not observed,and curative resection was achieved.CONCLUSION High-grade Pan-IN may cause MPD narrowing in a long range without caudal MPD dilatation. 展开更多
关键词 Pancreatic cancer Pancreatic intraepithelial neoplasm High-grade pancreatic intraepithelial neoplasm Magnetic resonance cholangiopancreatography Carcinoma in situ Case report
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