The Elephant Whisperer By Lawrence Anthony & Graham Spence Thomas Dunne Books when South African conservationist Lawrence Anthony was asked to accept a herd of "rogue" wild elephants on his Thula Thula g...The Elephant Whisperer By Lawrence Anthony & Graham Spence Thomas Dunne Books when South African conservationist Lawrence Anthony was asked to accept a herd of "rogue" wild elephants on his Thula Thula game reserve in Zululand.展开更多
Highly matched and precisely locked to the absorption lines of rubidium(Rb)atoms,780 nm lasers play a crucial role in fields such as quantum computing,precision measurements,and high-sensitivity sensing,with clear req...Highly matched and precisely locked to the absorption lines of rubidium(Rb)atoms,780 nm lasers play a crucial role in fields such as quantum computing,precision measurements,and high-sensitivity sensing,with clear requirements for strong coherence and fast tunability.In this paper,based on the self-injection locking and ultra-high quality factor whispering gallery mode(WGM)cavity,a 780 nm narrow linewidth(23.8 kHz)tunable laser with a single longitudinal mode output is verified.More importantly,benefiting from the optimized combined coupling coefficient K and via the lithium niobate electro-optic effect,the laser frequency detuning is ef⁃fectively improved,with the experimental tuning range reaching 110 pm and the tuning efficiency of 6.4 pm/V.This work provides a high-performance design solution for fast-tunable narrow-linewidth lasers for applications in the near-infrared range,which is expected to play an essential role in the future.展开更多
Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microca...Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microcavity-coupled fiber taper such as too fragile,unstable performance due to open coupling,poor portability and repeatability,while overcoming the poor performance of low refractive index sensing in general full-package fiber sensors.The sensor only needs a very small amount of liquid sample(about 1.8 nL).The proposed sensor combines the excellent performance of full package,optofluidics and WGM resonator.The resonant characteristics and sensing performance of the sensor are analyzed and discussed by the theoretical simulation.The simulation results indicate that the sensor has a wide refractive index sensing range(1.330-1.700)and good performance.The resonance wavelength shift has a good linear relationship with the liquid refractive index variation.In the low refractive index region,the sensitivity is 222.5-247.5 nm/RIU,Q-factor is 1.03×10^(3) and the detection limit is 3.64×10^(-4) RIU.In the medium and high refractive index regions,the sensitivity is 564.4-846.2 nm/RIU,Q-factor is up to 8.62×10^(4),and the detection limit can be as low as 1.29×10^(-6) RIU.The sensor exhibits a high sensitivity,a high Q-factor and a very low detection limit.展开更多
Microsphere and microcylinder-assisted microscopy(MAM)has grown steadily over the last decade and is still an intensively studied optical far-field imaging technique that promises to overcome the fundamental lateral r...Microsphere and microcylinder-assisted microscopy(MAM)has grown steadily over the last decade and is still an intensively studied optical far-field imaging technique that promises to overcome the fundamental lateral resolution limit of microscopy.However,the physical effects leading to resolution enhancement are still frequently debated.In addition,various configurations of MAM operating in transmission mode as well as reflection mode are examined,and the results are sometimes generalized.We present a rigorous simulation model of MAM and introduce a way to quantify the resolution enhancement.The lateral resolution is compared for microscope arrangements in reflection and transmission modes.Furthermore,we discuss different physical effects with respect to their contribution to resolution enhancement.The results indicate that the effects impacting the resolution in MAM strongly depend on the arrangement of the microscope and the measurement object.As a highlight,we outline that evanescent waves in combination with whispering gallery modes also improve the imaging capabilities,enabling super-resolution under certain circumstances.This result is contrary to the conclusions drawn from previous studies,where phase objects have been analyzed,and thus further emphasizes the complexity of the physical mechanisms underlying MAM.展开更多
This paper presents a biosensor utilizing a whispering gallery mode(WGM)resonator characterized by azimuthal symmetry and crescent-shaped coatings of silver.The study investigates the impact of the coupling gap on the...This paper presents a biosensor utilizing a whispering gallery mode(WGM)resonator characterized by azimuthal symmetry and crescent-shaped coatings of silver.The study investigates the impact of the coupling gap on the extinction ratio and Q-factor of the setup.The resonator is coated with silver in crescent shapes,ranging from 40 nm to 65 nm in thickness.Coupling is achieved with a silica waveguide,simulating the tapered fiber coupling method.Notably,the resonator exhibits a maximum sensitivity of 220 nm/RIU when coated with 55-nm-thick silver in conjunction with a 4-nm-thick layer of thiol-tethered deoxyribonucleic acid(DNA).This biosensor holds promise for biomolecule detection applications.展开更多
Chaotic microcavities play a crucial role in several research areas,including the study of unidirectional microlasers,nonlinear optics,sensing,quantum chaos,and non-Hermitian physics.To date,most theoretical and exper...Chaotic microcavities play a crucial role in several research areas,including the study of unidirectional microlasers,nonlinear optics,sensing,quantum chaos,and non-Hermitian physics.To date,most theoretical and experimental explorations have focused on two-dimensional(2D)chaotic dielectric microcavities,but there have been minimal studies on three-dimensional(3D)ones because precise geometrical information of a 3D microcavity can be difficult to obtain.Here,we image 3D microcavities with submicron resolution using X-ray microcomputed tomography(μCT),enabling nondestructive imaging that preserves the sample for subsequent use.By analyzing the ray dynamics of a typical deformed microsphere,we demonstrate that a sufficient deformation along all three dimensions can lead to chaotic ray trajectories over extended time scales.Notably,using the X-rayμCT reconstruction results,the phase space chaotic ray dynamics of a deformed microsphere are accurately established.X-rayμCT could become a unique platform for the characterization of such deformed 3D microcavities by providing a precise means for determining the degree of deformation necessary for potential applications in ray chaos and quantum chaos.展开更多
A machine learning based speech enhancement method is proposed to improve the intelligibility of whispered speech. A binary mask estimated by a two-class support vector machine （SVM） classifier is used to synthesize...A machine learning based speech enhancement method is proposed to improve the intelligibility of whispered speech. A binary mask estimated by a two-class support vector machine （SVM） classifier is used to synthesize the enhanced whisper. A novel noise robust feature called Gammatone feature cosine coefficients （GFCCs） extracted by an auditory periphery model is derived and used for the binary mask estimation. The intelligibility performance of the proposed method is evaluated and compared with the traditional speech enhancement methods. Objective and subjective evaluation results indicate that the proposed method can effectively improve the intelligibility of whispered speech which is contaminated by noise. Compared with the power subtract algorithm and the log-MMSE algorithm, both of which do not improve the intelligibility in lower signal-to-noise ratio （SNR） environments, the proposed method has good performance in improving the intelligibility of noisy whisper. Additionally, the intelligibility of the enhanced whispered speech using the proposed method also outperforms that of the corresponding unprocessed noisy whispered speech.展开更多
Some factors influencing the intelligibility of the enhanced whisper in the joint time-frequency domain are evaluated. Specifically, both the spectrum density and different regions of the enhanced spectrum are analyze...Some factors influencing the intelligibility of the enhanced whisper in the joint time-frequency domain are evaluated. Specifically, both the spectrum density and different regions of the enhanced spectrum are analyzed. Experimental results show that for a spectrum of some density, the joint time-frequency gain-modification based speech enhancement algorithm achieves significant improvement in intelligibility. Additionally, the spectrum region where the estimated spectrum is smaller than the clean spectrum, is the most important region contributing to intelligibility improvement for the enhanced whisper. The spectrum region where the estimated spectrum is larger than twice the size of the clean spectrum is detrimental to speech intelligibility perception within the whisper context.展开更多
The cognitive performance-based dimensional emotion recognition in whispered speech is studied.First,the whispered speech emotion databases and data collection methods are compared, and the character of emotion expres...The cognitive performance-based dimensional emotion recognition in whispered speech is studied.First,the whispered speech emotion databases and data collection methods are compared, and the character of emotion expression in whispered speech is studied,especially the basic types of emotions.Secondly,the emotion features for whispered speech is analyzed,and by reviewing the latest references,the related valence features and the arousal features are provided. The effectiveness of valence and arousal features in whispered speech emotion classification is studied.Finally,the Gaussian mixture model is studied and applied to whispered speech emotion recognition. The cognitive performance is also considered in emotion recognition so that the recognition errors of whispered speech emotion can be corrected.Based on the cognitive scores,the emotion recognition results can be improved.The results show that the formant features are not significantly related to arousal dimension,while the short-term energy features are related to the emotion changes in arousal dimension.Using the cognitive scores,the recognition results can be improved.展开更多
Objectives: The study aimed to determine the most appropriate hearing screening test to identify disabling hearing loss for adults aged 65 years or older.Methods: This study included 577 older adults. Four hearing scr...Objectives: The study aimed to determine the most appropriate hearing screening test to identify disabling hearing loss for adults aged 65 years or older.Methods: This study included 577 older adults. Four hearing screening tests were considered in the study, including the Hearing Handicap Inventory for Elderly Screening(HHIE-s), three single question tests, the whisper test, and the finger rub test. The sensitivity and specificity of these tests referenced to the hearing threshold of disabling hearing loss were estimated.Results: Among all tests, only the single self-perception question(0.7064 for sensitivity;0.7225 for specificity) and whisper test(0.7833 for sensitivity;0.7708 for specificity) could obtain both sensitivity and specificity higher than 70% for adults aged ≥65 years.Conclusion: Overall, we suggest using the whisper test to identify disabling hearing loss(>40 dB HL at the better ear) for adults aged 65 years or older. However, if the conditions do not permit, the single selfperception question is also acceptable. Moreover, HHIE-s might not be a good test to detect disabling hearing loss for adults aged 80 years or older.展开更多
Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the s...Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the solid immersion mechanism into the slab superlens and the cylindrical superlens. The proposed solid immersion slab superlens(SISSL) and the solid immersion cylindrical superlens(SICSL) can improve the resolution by converting evanescent wave to propagating wave using high refractive index materials. From the perspective of applications, the cylindrical superlens with finite cross section and the ability of magnification or demagnification has more advantages than the slab superlens. Therefore,we focus on demonstrating analytically the super-resolution imaging of SICSL. Due to the impedance mismatching caused by solid immersion mechanism, the whispering gallery modes(WGMs) are excited between SICSL and the air interface.We clarify the excitation conditions of WGMs and analyze their influence on the imaging quality of SICSL. The SISSL and SICSL may pave a way to apply in lithography technique and real-time biomolecular imaging in future.展开更多
文摘The Elephant Whisperer By Lawrence Anthony & Graham Spence Thomas Dunne Books when South African conservationist Lawrence Anthony was asked to accept a herd of "rogue" wild elephants on his Thula Thula game reserve in Zululand.
基金Supported by the General Program of National Natural Science Foundation of China(62373331)the Joint Funds of the National Natural Science Foundation of China(U21A20141)+1 种基金the Innovative Research Group Project of the National Natural Science Foundation of China(51821003)the Natural Science Foundation of Shanxi Province(202403021211095).
文摘Highly matched and precisely locked to the absorption lines of rubidium(Rb)atoms,780 nm lasers play a crucial role in fields such as quantum computing,precision measurements,and high-sensitivity sensing,with clear requirements for strong coherence and fast tunability.In this paper,based on the self-injection locking and ultra-high quality factor whispering gallery mode(WGM)cavity,a 780 nm narrow linewidth(23.8 kHz)tunable laser with a single longitudinal mode output is verified.More importantly,benefiting from the optimized combined coupling coefficient K and via the lithium niobate electro-optic effect,the laser frequency detuning is ef⁃fectively improved,with the experimental tuning range reaching 110 pm and the tuning efficiency of 6.4 pm/V.This work provides a high-performance design solution for fast-tunable narrow-linewidth lasers for applications in the near-infrared range,which is expected to play an essential role in the future.
基金supported by the National Natural Science Foundation of China(No.12174199)the Wanjing Horizontal Research and Development Fund for Nature(No.HJ1060319960015).
文摘Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microcavity-coupled fiber taper such as too fragile,unstable performance due to open coupling,poor portability and repeatability,while overcoming the poor performance of low refractive index sensing in general full-package fiber sensors.The sensor only needs a very small amount of liquid sample(about 1.8 nL).The proposed sensor combines the excellent performance of full package,optofluidics and WGM resonator.The resonant characteristics and sensing performance of the sensor are analyzed and discussed by the theoretical simulation.The simulation results indicate that the sensor has a wide refractive index sensing range(1.330-1.700)and good performance.The resonance wavelength shift has a good linear relationship with the liquid refractive index variation.In the low refractive index region,the sensitivity is 222.5-247.5 nm/RIU,Q-factor is 1.03×10^(3) and the detection limit is 3.64×10^(-4) RIU.In the medium and high refractive index regions,the sensitivity is 564.4-846.2 nm/RIU,Q-factor is up to 8.62×10^(4),and the detection limit can be as low as 1.29×10^(-6) RIU.The sensor exhibits a high sensitivity,a high Q-factor and a very low detection limit.
基金supported by the German Research Foundation(DFG)(Grant Nos.LE 992/14-3 and LE 992/15-3).
文摘Microsphere and microcylinder-assisted microscopy(MAM)has grown steadily over the last decade and is still an intensively studied optical far-field imaging technique that promises to overcome the fundamental lateral resolution limit of microscopy.However,the physical effects leading to resolution enhancement are still frequently debated.In addition,various configurations of MAM operating in transmission mode as well as reflection mode are examined,and the results are sometimes generalized.We present a rigorous simulation model of MAM and introduce a way to quantify the resolution enhancement.The lateral resolution is compared for microscope arrangements in reflection and transmission modes.Furthermore,we discuss different physical effects with respect to their contribution to resolution enhancement.The results indicate that the effects impacting the resolution in MAM strongly depend on the arrangement of the microscope and the measurement object.As a highlight,we outline that evanescent waves in combination with whispering gallery modes also improve the imaging capabilities,enabling super-resolution under certain circumstances.This result is contrary to the conclusions drawn from previous studies,where phase objects have been analyzed,and thus further emphasizes the complexity of the physical mechanisms underlying MAM.
基金supported by the Airlangga University through Mandate Research Grant(Nos.216/UN3.15/PT/2022 and 217/UN3.15/PT/2022)。
文摘This paper presents a biosensor utilizing a whispering gallery mode(WGM)resonator characterized by azimuthal symmetry and crescent-shaped coatings of silver.The study investigates the impact of the coupling gap on the extinction ratio and Q-factor of the setup.The resonator is coated with silver in crescent shapes,ranging from 40 nm to 65 nm in thickness.Coupling is achieved with a silica waveguide,simulating the tapered fiber coupling method.Notably,the resonator exhibits a maximum sensitivity of 220 nm/RIU when coated with 55-nm-thick silver in conjunction with a 4-nm-thick layer of thiol-tethered deoxyribonucleic acid(DNA).This biosensor holds promise for biomolecule detection applications.
基金support from the Okinawa Institute of Science and Technology Graduate University(OIST),the China Scholarship Council(CSC)(Grant No.202306680004)the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Korean government(MSIT)(Grant Nos.RS-2024-00403036 and RS-202500521202)+2 种基金support from the Japan Society for the Promotion of Science(JSPS)KAKENHI through Grant-in-Aid for Scientific Research(C)(Grant No.23K04617)Grant-in-Aid for Early-Career Scientists(Grant No.22K14621)Grant-in-Aid for JSPS fellows(Grant No.25KJ2244)。
文摘Chaotic microcavities play a crucial role in several research areas,including the study of unidirectional microlasers,nonlinear optics,sensing,quantum chaos,and non-Hermitian physics.To date,most theoretical and experimental explorations have focused on two-dimensional(2D)chaotic dielectric microcavities,but there have been minimal studies on three-dimensional(3D)ones because precise geometrical information of a 3D microcavity can be difficult to obtain.Here,we image 3D microcavities with submicron resolution using X-ray microcomputed tomography(μCT),enabling nondestructive imaging that preserves the sample for subsequent use.By analyzing the ray dynamics of a typical deformed microsphere,we demonstrate that a sufficient deformation along all three dimensions can lead to chaotic ray trajectories over extended time scales.Notably,using the X-rayμCT reconstruction results,the phase space chaotic ray dynamics of a deformed microsphere are accurately established.X-rayμCT could become a unique platform for the characterization of such deformed 3D microcavities by providing a precise means for determining the degree of deformation necessary for potential applications in ray chaos and quantum chaos.
基金The National Natural Science Foundation of China (No.61231002,61273266,51075068,60872073,60975017, 61003131)the Ph.D.Programs Foundation of the Ministry of Education of China(No.20110092130004)+1 种基金the Science Foundation for Young Talents in the Educational Committee of Anhui Province(No. 2010SQRL018)the 211 Project of Anhui University(No.2009QN027B)
文摘A machine learning based speech enhancement method is proposed to improve the intelligibility of whispered speech. A binary mask estimated by a two-class support vector machine （SVM） classifier is used to synthesize the enhanced whisper. A novel noise robust feature called Gammatone feature cosine coefficients （GFCCs） extracted by an auditory periphery model is derived and used for the binary mask estimation. The intelligibility performance of the proposed method is evaluated and compared with the traditional speech enhancement methods. Objective and subjective evaluation results indicate that the proposed method can effectively improve the intelligibility of whispered speech which is contaminated by noise. Compared with the power subtract algorithm and the log-MMSE algorithm, both of which do not improve the intelligibility in lower signal-to-noise ratio （SNR） environments, the proposed method has good performance in improving the intelligibility of noisy whisper. Additionally, the intelligibility of the enhanced whispered speech using the proposed method also outperforms that of the corresponding unprocessed noisy whispered speech.
基金The National Natural Science Foundation of China(No.61301295,61273266,61301219,61201326,61003131)the Natural Science Foundation of Anhui Province(No.1308085QF100,1408085MF113)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20130241)the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(No.12KJB510021)the Doctoral Fund of Anhui University
文摘Some factors influencing the intelligibility of the enhanced whisper in the joint time-frequency domain are evaluated. Specifically, both the spectrum density and different regions of the enhanced spectrum are analyzed. Experimental results show that for a spectrum of some density, the joint time-frequency gain-modification based speech enhancement algorithm achieves significant improvement in intelligibility. Additionally, the spectrum region where the estimated spectrum is smaller than the clean spectrum, is the most important region contributing to intelligibility improvement for the enhanced whisper. The spectrum region where the estimated spectrum is larger than twice the size of the clean spectrum is detrimental to speech intelligibility perception within the whisper context.
基金The National Natural Science Foundation of China(No.11401412)
文摘The cognitive performance-based dimensional emotion recognition in whispered speech is studied.First,the whispered speech emotion databases and data collection methods are compared, and the character of emotion expression in whispered speech is studied,especially the basic types of emotions.Secondly,the emotion features for whispered speech is analyzed,and by reviewing the latest references,the related valence features and the arousal features are provided. The effectiveness of valence and arousal features in whispered speech emotion classification is studied.Finally,the Gaussian mixture model is studied and applied to whispered speech emotion recognition. The cognitive performance is also considered in emotion recognition so that the recognition errors of whispered speech emotion can be corrected.Based on the cognitive scores,the emotion recognition results can be improved.The results show that the formant features are not significantly related to arousal dimension,while the short-term energy features are related to the emotion changes in arousal dimension.Using the cognitive scores,the recognition results can be improved.
文摘Objectives: The study aimed to determine the most appropriate hearing screening test to identify disabling hearing loss for adults aged 65 years or older.Methods: This study included 577 older adults. Four hearing screening tests were considered in the study, including the Hearing Handicap Inventory for Elderly Screening(HHIE-s), three single question tests, the whisper test, and the finger rub test. The sensitivity and specificity of these tests referenced to the hearing threshold of disabling hearing loss were estimated.Results: Among all tests, only the single self-perception question(0.7064 for sensitivity;0.7225 for specificity) and whisper test(0.7833 for sensitivity;0.7708 for specificity) could obtain both sensitivity and specificity higher than 70% for adults aged ≥65 years.Conclusion: Overall, we suggest using the whisper test to identify disabling hearing loss(>40 dB HL at the better ear) for adults aged 65 years or older. However, if the conditions do not permit, the single selfperception question is also acceptable. Moreover, HHIE-s might not be a good test to detect disabling hearing loss for adults aged 80 years or older.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2020YFA0710100)the National Natural Science Foundation of China (Grant Nos. 92050102 and 11874311)the Fundamental Research Funds for the Central Universities (Grant Nos. 20720220033 and 20720200074)。
文摘Super-resolution imaging with superlens has been one of the fundamental research topics. Unfortunately, the resolution of superlens is inevitably restrained by material loss. To address the problem, we introduce the solid immersion mechanism into the slab superlens and the cylindrical superlens. The proposed solid immersion slab superlens(SISSL) and the solid immersion cylindrical superlens(SICSL) can improve the resolution by converting evanescent wave to propagating wave using high refractive index materials. From the perspective of applications, the cylindrical superlens with finite cross section and the ability of magnification or demagnification has more advantages than the slab superlens. Therefore,we focus on demonstrating analytically the super-resolution imaging of SICSL. Due to the impedance mismatching caused by solid immersion mechanism, the whispering gallery modes(WGMs) are excited between SICSL and the air interface.We clarify the excitation conditions of WGMs and analyze their influence on the imaging quality of SICSL. The SISSL and SICSL may pave a way to apply in lithography technique and real-time biomolecular imaging in future.
