Various specific laser irradiance distribution outputs are needed in many applications. To fulfill this need, a detailed step-by-step design procedure for split refracting system is proposed for three types of laser b...Various specific laser irradiance distribution outputs are needed in many applications. To fulfill this need, a detailed step-by-step design procedure for split refracting system is proposed for three types of laser beams transformation: 1) Annular-uniform-to-uniform;2) Annular-Gaussian-to-uniform;and 3) Gaussian-to-uniform to obtain the required laser irradiance distributions. Mathematical expressions of the two Plano-aspheric surfaces are derived for each type. The proposed designs take into account few important parameters such as the system length, the surfaces radii of curvature, the annular beam starting cone angle, and the beams power ratio. Further, the proposed designs are much better than the ones, which were previously展开更多
The limitation of paraxial condition of paraboloid refracting system in performing fractional Fourier transform acts like an aperture, which makes the system different from ideal systems. With aperture expanded as the...The limitation of paraxial condition of paraboloid refracting system in performing fractional Fourier transform acts like an aperture, which makes the system different from ideal systems. With aperture expanded as the sum of finite complex Gaussian terms, a more practical approximate analytical solution of fractional Fourier transform of Gaussian beam in an apertured paraboloid refracting system is obtained and also numerical investigation is presented. Complicated and practical fractional Fourier transform systems can be constructed by cascading several apertured paraboloid refracting systems which are the simplest and the most basic units for performing more precise transform.展开更多
To address the temperature cross-talk issue in detecting heavy metal ions in natural waters, a highly-integrated and fully fiber-optic metal ion sensing system capable of temperature-concentration decoupling measureme...To address the temperature cross-talk issue in detecting heavy metal ions in natural waters, a highly-integrated and fully fiber-optic metal ion sensing system capable of temperature-concentration decoupling measurement has been designed. This system integrates a fluidic detection structure assisted by side-polished fibers(SPFs) with a Sagnac interferometer.展开更多
AIM:To evaluate the efficacy of the total computer vision syndrome questionnaire(CVS-Q)score as a predictive tool for identifying individuals with symptomatic binocular vision anomalies and refractive errors.METHODS:A...AIM:To evaluate the efficacy of the total computer vision syndrome questionnaire(CVS-Q)score as a predictive tool for identifying individuals with symptomatic binocular vision anomalies and refractive errors.METHODS:A total of 141 healthy computer users underwent comprehensive clinical visual function assessments,including evaluations of refractive errors,accommodation(amplitude of accommodation,positive relative accommodation,negative relative accommodation,accommodative accuracy,and accommodative facility),and vergence(phoria,positive and negative fusional vergence,near point of convergence,and vergence facility).Total CVS-Q scores were recorded to explore potential associations between symptom scores and the aforementioned clinical visual function parameters.RESULTS:The cohort included 54 males(38.3%)with a mean age of 23.9±0.58y and 87 age-matched females(61.7%)with a mean age of 23.9±0.53y.The multiple regression model was statistically significant[R²=0.60,F=13.28,degrees of freedom(DF=17122,P<0.001].This indicates that 60%of the variance in total CVS-Q scores(reflecting reported symptoms)could be explained by four clinical measurements:amplitude of accommodation,positive relative accommodation,exophoria at distance and near,and positive fusional vergence at near.CONCLUSION:The total CVS-Q score is a valid and reliable tool for predicting the presence of various nonstrabismic binocular vision anomalies and refractive errors in symptomatic computer users.展开更多
AIM:To ascertain the pattern of ocular morbidity in a population of primary school children in rural Kenya as it is a prerequisite for planning effective preventive and therapeutic strategies.METHODS:A cross-sectional...AIM:To ascertain the pattern of ocular morbidity in a population of primary school children in rural Kenya as it is a prerequisite for planning effective preventive and therapeutic strategies.METHODS:A cross-sectional survey of ocular symptoms and clinical eye examinations were performed in a sample of 35 rural primary schools in the semi-arid region of Kajiado West sub-county in S.W.Kenya,amongst a seminomadic tribe(Maasai).Students in Grades 1-8 were included.Visual acuity was measured using the Snellen“tumbling E”chart at 6 m.Children with symptoms of refractive error underwent non-cycloplegic refraction.RESULTS:A total of 2036 children(1084 males)between the ages of 4-20y were examined.Conjunctival actinic changes were present in 22%(442/2036).Nine cases were seen with a potential squamous carcinoma.No overt classical ocular signs of vitamin A deficiency were noted,although 181(8.9%)children complained of nyctalopia.Three hundred thirty-six(16.5%)children had a visual acuity worse than 6/12 in either eye,were unable to read N10 near text at 40 cm or had symptoms suggestive of refractive error.Refractive data led to an estimate of hyperopia of+1.00 D or more in 3.9%and of myopia of-0.50 D or more in either eye in 3.0%of the study population.CONCLUSION:Solar exposure-and dust-related conjunctival pathology is common.As this may develop into potentially sight-or even life-threatening conditions,it warrants further study,and preventive strategies may be needed.Complaints of nyctalopia were common and could suggest vitamin A deficiency.The prevalence of refractive errors is low in this rural African population.展开更多
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group...AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.展开更多
Dear Editor,We present this case report which discusses a patient who underwent flap amputation after repeated attempts to resolve persistent and severe epithelial ingrowth following laser-assisted in situ keratomileu...Dear Editor,We present this case report which discusses a patient who underwent flap amputation after repeated attempts to resolve persistent and severe epithelial ingrowth following laser-assisted in situ keratomileusis(LASIK)surgery.Epithelial ingrowth is a known complication of LASIK surgery,typically manageable with minimal measures.However,severe cases may necessitate more aggressive interventions,such as flap amputation[1].LASIK is a widely performed refractive surgery with high success rates and excellent visual outcome[2].展开更多
Ocular biological characteristics and refractive errors in children with unilateral congenital ptosis Yu-Ying Sun,Bing-Ying Lin,Zhen Mao,Xuan-Wei Liang,Cui-Yu Zhang,Dan-Ping Huang,Yao Ni,Zuo-Hong Li Int J Ophthalmol 2...Ocular biological characteristics and refractive errors in children with unilateral congenital ptosis Yu-Ying Sun,Bing-Ying Lin,Zhen Mao,Xuan-Wei Liang,Cui-Yu Zhang,Dan-Ping Huang,Yao Ni,Zuo-Hong Li Int J Ophthalmol 2025;18(4):691-698.DOI:10.18240/ijo.2025.04.16 The author requests to change the authorship and affiliations as follows.展开更多
Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are id...Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are ideal candidates for GRIN metalenses.Digital light processing(DLP)3D printing provides a feasible and efficient approach for manufacturing ceramic GRIN metalenses.However,the scattering of ultraviolet(UV)light by ceramic particles in the slurry reduces the printing accuracy of DLP technology,making it difficult to achieve the intricate structural features required for GRIN metalenses in high-frequency communication.In this work,we propose an approach to improve printing accuracy by optimizing the ceramic slurry composition and implementing a dimensional compensation design strategy.Utilizing geometric optics and the S-parameter inversion method,we design a GRIN metalens consisting of two distinct types of subwavelength unit cells(Y-shaped and circular hole geometries)with a minimum feature size of 160μm.Through a refined slurry formulation and precise design parameter compensation,high-fidelity ceramic GRIN metalenses are successfully fabricated.The fabricated metalens exhibits a maximum gain enhancement of 18.4 dBi and a deflection angle of±30°over a bandwidth of 37.84% in the W-band(75-110 GHz).The highly directional far-field beam radiation and efficient beam steering capabilities highlight the potential of ceramic GRIN metalenses for applications in satellite communications,radar systems,and other high-frequency technologies.展开更多
Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)...Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.展开更多
Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such a...Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such ashigh-vacuum, high-pressure, and strong magnetic fields compared with the traditional electrical sensing technology.However, with the increasing application requirements, how to further improve the sensitivity of fiber-optic sensors,extend the detection limit and improve the maintenance-free capability has become one of the core issues of thecurrent research. This paper reviews the principle, preparation, and application of fiber-optic microstructured sensingbased on abrupt field type. It specifically outlines the development and applications of micro-nano optical fibers,photonic crystal optical fibers, optical fiber gratings and structured optical fibers, and lists the main preparationmethods of two types of micro-nano optical fibers from the basic theory of optical fiber microstructured sensordevices.展开更多
AIM:To evaluate the visual function and optical quality in adults aged 80y and older following the bilateral implantation of zonal refractive multifocal intraocular lens(IOL,LS-313 MF30).METHODS:A single-center,non-ra...AIM:To evaluate the visual function and optical quality in adults aged 80y and older following the bilateral implantation of zonal refractive multifocal intraocular lens(IOL,LS-313 MF30).METHODS:A single-center,non-randomized,prospective clinical trial was conducted,involving cataract patients aged 80 y and older.Patients received bilateral implantation of the LS-313 MF30 or CT Asphina 409MP,based on personal preference.Postoperative assessments included uncorrected and corrected visual acuity at distance,intermediate,and near ranges,as well as defocus curve.Subjective evaluations were performed using the visual function(VF-14)questionnaire,spectacle independence rates,and patient satisfaction surveys.Photic phenomena such as glare,halos,and starbursts were also analyzed.RESULTS:The MF30 group(16 eyes from 8 participants,85.38±2.56 y)exhibited superior uncorrected and corrected intermediate and near visual acuity compared to the 409MP group(26 eyes from 13 participants,85.77±2.20 y),while distance visual acuity was comparable between groups.The defocus curve of the MF30 group revealed two peaks at 0.00 D and-3.00 D,indicating a broader depth of focus.Patients in the MF30 group reported higher rates of spectacle independence and greater satisfaction.While photic phenomena such as glare(28.6%vs 18.5%,P=0.584),starburst(9.5%vs 3.7%,P=0.567)and halos(23.8%vs 11.11%,P=0.438)were more prevalent in the MF30 group,they were generally mild and did not significantly impact daily activities.CONCLUSION:Zonal refractive multifocal IOLs provide elderly patients with improved distance and near vision,greater spectacle independence,and greater satisfaction.Although photic phenomena were slightly more frequent with MF30,they are generally reported as non-disruptive and do not affect their daily life compared to monofocal IOLs.展开更多
Traditional methods of residual stress measurement are generally destructive or semi-destructive, as well as expensive, time-consuming and complex to implement. With the new development of welded structure, traditiona...Traditional methods of residual stress measurement are generally destructive or semi-destructive, as well as expensive, time-consuming and complex to implement. With the new development of welded structure, traditional methods can not satisfy the need of full life task management. So the acoustical theory is introduced, since the ultrasonic technique provides a useful nondestructive tool in the evaluation of stresses. In this study an ultrasonic stress measurement experimental installation is established, which consists of a special transducer, a signal emission unit and a signal recipient processing unit. Longitudinal critically refracted wave is selected as the measurement wave mode. The supporting software is programmed by Labview software. The longitudinal residual stress and transverse residual stress of twin wire welded plate are measured by this installment, in which the measuring process is real-time, quick and nondestructive. The experiment results indicate that the system can satisfy the need of life evaluation for welded structure. The system is light and portable.展开更多
This paper presents a novel approach for assessing the precision of the wet refractivity field using BDS （BeiDou navigation satellite system） simulations only,GPS,and BDS＋GPS for the Shenzhen and Hongkong GNSS netw...This paper presents a novel approach for assessing the precision of the wet refractivity field using BDS （BeiDou navigation satellite system） simulations only,GPS,and BDS＋GPS for the Shenzhen and Hongkong GNSS network.The simulations are carried out by adding artificial noise to a real observation dataset.Instead of using the δ and σ parameters computed from slant wet delay,as in previous studies,we employ the Bias and RMS parameters,computed from the tomography results of total voxels,in order to obtain a more direct and comprehensive evaluation of the precision of the refractivity field determination.The results show that：（1） the precision of tropospheric wet refractivity estimated using BDS alone （only 9 satellites used） is basically comparable to that of GPS; （2） BDS＋GPS （as of current operation） may not be able to significantly improve the data＇s spatial density for the application of refractivity tomography; and （3） any slight increase in the precision of refractivity tomography,particularly in the lower atmosphere,bears great significance for any applications dependent on the Chinese operational meteorological service.展开更多
AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction ...AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction was performed on 125 eyes of 65 healthy adults(age 23.5±3.0 years) from October 2010 to January 2011 using retinoscopy,subjective refraction,autorefraction(Auto kerato refractometer TOPCON KR-8100,Japan) and a double pass system(Optical Quality Analysis System,OQAS,Visiometrics S.L.,Spain).Nine consecutive measurements with the double-pass system were performed on a subgroup of 22 eyes to assess repeatability.To evaluate the trueness of the OQAS instrument,the SE laboratory bias between the double pass system and the other techniques was calculated.RESULTS:The SE mean coefficient of repeatability obtained was 0.22D.Significant correlations could be established between the OQAS and the SE obtained with retinoscopy(r=0.956,P【0.001),subjective refraction(r=0.955,P【0.001) and autorefraction(r=0.957,P【0.001).The differences in SE between the double-pass system and the other techniques were significant(P【0.001),but lacked clinical relevance except for retinoscopy;Retinoscopy gave more hyperopic values than the double-pass system-0.51±0.50D as well as the subjective refraction-0.23±0.50D;More myopic values were achieved by means of autorefraction 0.24±0.49D. CONCLUSION:The double-pass system provides accurate and reliable estimates of the SE that can be used for clinical studies.This technique can determine the correct focus position to assess the ocular optical quality.However,it has a relatively small measuring range in comparison with autorefractors(-8.00 to +5.00D),and requires prior information on the refractive state of the patient.展开更多
We present a detailed theoretical description of wave propagation in an acoustic gradient-index system with cylindrical symmetry and demonstrate its potential to numerically control acoustic waves in different ways.Th...We present a detailed theoretical description of wave propagation in an acoustic gradient-index system with cylindrical symmetry and demonstrate its potential to numerically control acoustic waves in different ways.The trajectory of an acoustic wave within the system is derived by employing the theory of geometric acoustics,and the validity of the theoretical descriptions is verified numerically by using the finite element method simulation.The results show that by tailoring the distribution function of the refractive index,the proposed system can yield a tunable manipulation of acoustic waves,such as acoustic bending,trapping,and absorbing.展开更多
The glass forming region of Bi2O3-B2O3-BaO ternary system was investigated. A serial of glass samples with high Bi2O3 content in Bi2O3-B2O3-BaO system were prepared by using conventional melting and quenching meld, an...The glass forming region of Bi2O3-B2O3-BaO ternary system was investigated. A serial of glass samples with high Bi2O3 content in Bi2O3-B2O3-BaO system were prepared by using conventional melting and quenching meld, and the refractive indexes and absorption spectra of samples were measured. It is found that the refractive index of samples as well as the UV absorption increase with the increase of BaO content. According to the Tauc law, optical band gap Eopg which is assumed to be the effective energy band gap Eg is calculated and decreases with the increasing BaO content, and the ratio of Eg/Eopg is 1.3.展开更多
The problems involving scattering and refracting of plane strain wave by a cylinder in fluidsaturated soils are studied in this paper. The theoretical solutions for the amplitudes of scattering and refracting are deri...The problems involving scattering and refracting of plane strain wave by a cylinder in fluidsaturated soils are studied in this paper. The theoretical solutions for the amplitudes of scattering and refracting are derived on the basis of modified Biot′s theory for twophase medium in engineering, in which the compressibility of soil grains and the viscous coupling effect between the skeletal frame and the pore fluid are taken into account. Moreover, the amplitude equations of potential function are presented when the fluidsaturated soil cylindrical inclusion is degenerated into cylindrical cavity, rigid cylinder, single phase elastic cylinder and single phase fluid cylinder.展开更多
The influence of solvent on the miscibility of polystyrene（PS） and poly（styrene-co-acrylonitrile）（PSAN） blends has been investigated viscometrically. The miscibility of different PS/PSAN blend（30/70, 50/50 and ...The influence of solvent on the miscibility of polystyrene（PS） and poly（styrene-co-acrylonitrile）（PSAN） blends has been investigated viscometrically. The miscibility of different PS/PSAN blend（30/70, 50/50 and 70/30） compositions in acetone and benzene at 20, 30, and 40 °C was investigated on the basis of the sign of Chee（ΔB and ）, and Sun’s（α） criteria. The values of these parameters were evaluated from the analyses of reduced viscosity data of binary（solvent/polymer） and ternary（solvent/polymer1/polymer2） polymer systems. These investigations indicated partial miscibility for both the blend systems. However, PS/PSAN/acetone blend system showed somewhat higher partial miscibility than the PS/PSAN/Benzene blend system highlighting the impact of solvent over the polymer-polymer interactions and hence their miscibility. The results obtained through viscometry were also corroborated by the refractive index and density results for the blends under study. The effect of temperature on miscibility in both the cases was almost negligible.展开更多
Dynamic nonlinearities of C70/toluene solution are measured and analysed by an improved picosecond timeresolved pump-probe system based on a nonlinear imaging technique with phase object. The photophysical parameters ...Dynamic nonlinearities of C70/toluene solution are measured and analysed by an improved picosecond timeresolved pump-probe system based on a nonlinear imaging technique with phase object. The photophysical parameters are determined by the five-level model, which is adopted to interpret the experimental data. The change of refraction index per unit density of the excited state obtained by a numerically simulation is a critical factor to determine the nonlinear behaviour of C70 in picosecond time regime.展开更多
文摘Various specific laser irradiance distribution outputs are needed in many applications. To fulfill this need, a detailed step-by-step design procedure for split refracting system is proposed for three types of laser beams transformation: 1) Annular-uniform-to-uniform;2) Annular-Gaussian-to-uniform;and 3) Gaussian-to-uniform to obtain the required laser irradiance distributions. Mathematical expressions of the two Plano-aspheric surfaces are derived for each type. The proposed designs take into account few important parameters such as the system length, the surfaces radii of curvature, the annular beam starting cone angle, and the beams power ratio. Further, the proposed designs are much better than the ones, which were previously
基金This work was supported by Ludong University Re-search Foundation under Grant No. 20042811.
文摘The limitation of paraxial condition of paraboloid refracting system in performing fractional Fourier transform acts like an aperture, which makes the system different from ideal systems. With aperture expanded as the sum of finite complex Gaussian terms, a more practical approximate analytical solution of fractional Fourier transform of Gaussian beam in an apertured paraboloid refracting system is obtained and also numerical investigation is presented. Complicated and practical fractional Fourier transform systems can be constructed by cascading several apertured paraboloid refracting systems which are the simplest and the most basic units for performing more precise transform.
基金supported by the National Natural Science Foundation of China(Nos.61705027,62375031 and 52075131)the Chongqing Science and Technology Commission Basic Research Project(No.CSTC-2020jcyj-msxm0603)the Chongqing Municipal Education Commission Science and Technology Research Program(No.KJQN202000609)。
文摘To address the temperature cross-talk issue in detecting heavy metal ions in natural waters, a highly-integrated and fully fiber-optic metal ion sensing system capable of temperature-concentration decoupling measurement has been designed. This system integrates a fluidic detection structure assisted by side-polished fibers(SPFs) with a Sagnac interferometer.
基金Supported by Ongoing Research Funding Program(ORFFT-2025-054-1),King Saud University,Riyadh,Saudi Arabia.
文摘AIM:To evaluate the efficacy of the total computer vision syndrome questionnaire(CVS-Q)score as a predictive tool for identifying individuals with symptomatic binocular vision anomalies and refractive errors.METHODS:A total of 141 healthy computer users underwent comprehensive clinical visual function assessments,including evaluations of refractive errors,accommodation(amplitude of accommodation,positive relative accommodation,negative relative accommodation,accommodative accuracy,and accommodative facility),and vergence(phoria,positive and negative fusional vergence,near point of convergence,and vergence facility).Total CVS-Q scores were recorded to explore potential associations between symptom scores and the aforementioned clinical visual function parameters.RESULTS:The cohort included 54 males(38.3%)with a mean age of 23.9±0.58y and 87 age-matched females(61.7%)with a mean age of 23.9±0.53y.The multiple regression model was statistically significant[R²=0.60,F=13.28,degrees of freedom(DF=17122,P<0.001].This indicates that 60%of the variance in total CVS-Q scores(reflecting reported symptoms)could be explained by four clinical measurements:amplitude of accommodation,positive relative accommodation,exophoria at distance and near,and positive fusional vergence at near.CONCLUSION:The total CVS-Q score is a valid and reliable tool for predicting the presence of various nonstrabismic binocular vision anomalies and refractive errors in symptomatic computer users.
基金Supported by Vision International Eye Missions-USA,“One Drop for All”,Italy,and Private Donors in the Netherlands.
文摘AIM:To ascertain the pattern of ocular morbidity in a population of primary school children in rural Kenya as it is a prerequisite for planning effective preventive and therapeutic strategies.METHODS:A cross-sectional survey of ocular symptoms and clinical eye examinations were performed in a sample of 35 rural primary schools in the semi-arid region of Kajiado West sub-county in S.W.Kenya,amongst a seminomadic tribe(Maasai).Students in Grades 1-8 were included.Visual acuity was measured using the Snellen“tumbling E”chart at 6 m.Children with symptoms of refractive error underwent non-cycloplegic refraction.RESULTS:A total of 2036 children(1084 males)between the ages of 4-20y were examined.Conjunctival actinic changes were present in 22%(442/2036).Nine cases were seen with a potential squamous carcinoma.No overt classical ocular signs of vitamin A deficiency were noted,although 181(8.9%)children complained of nyctalopia.Three hundred thirty-six(16.5%)children had a visual acuity worse than 6/12 in either eye,were unable to read N10 near text at 40 cm or had symptoms suggestive of refractive error.Refractive data led to an estimate of hyperopia of+1.00 D or more in 3.9%and of myopia of-0.50 D or more in either eye in 3.0%of the study population.CONCLUSION:Solar exposure-and dust-related conjunctival pathology is common.As this may develop into potentially sight-or even life-threatening conditions,it warrants further study,and preventive strategies may be needed.Complaints of nyctalopia were common and could suggest vitamin A deficiency.The prevalence of refractive errors is low in this rural African population.
基金Supported by the Zhejiang Medical Health Science and Technology Project(No.2021KY217)the Basic Public Welfare Research Project of Wenzhou Municipal Science and Technology Bureau(No.2024Y1221).
文摘AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.
文摘Dear Editor,We present this case report which discusses a patient who underwent flap amputation after repeated attempts to resolve persistent and severe epithelial ingrowth following laser-assisted in situ keratomileusis(LASIK)surgery.Epithelial ingrowth is a known complication of LASIK surgery,typically manageable with minimal measures.However,severe cases may necessitate more aggressive interventions,such as flap amputation[1].LASIK is a widely performed refractive surgery with high success rates and excellent visual outcome[2].
文摘Ocular biological characteristics and refractive errors in children with unilateral congenital ptosis Yu-Ying Sun,Bing-Ying Lin,Zhen Mao,Xuan-Wei Liang,Cui-Yu Zhang,Dan-Ping Huang,Yao Ni,Zuo-Hong Li Int J Ophthalmol 2025;18(4):691-698.DOI:10.18240/ijo.2025.04.16 The author requests to change the authorship and affiliations as follows.
基金financial support by the National Key Research and Development Program of China(No.2023YFB4605400)the National Natural Science Foundation of China(No.12472152)the Department of Science and Technology of Guangdong Province(No.2019QN01Z438)。
文摘Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are ideal candidates for GRIN metalenses.Digital light processing(DLP)3D printing provides a feasible and efficient approach for manufacturing ceramic GRIN metalenses.However,the scattering of ultraviolet(UV)light by ceramic particles in the slurry reduces the printing accuracy of DLP technology,making it difficult to achieve the intricate structural features required for GRIN metalenses in high-frequency communication.In this work,we propose an approach to improve printing accuracy by optimizing the ceramic slurry composition and implementing a dimensional compensation design strategy.Utilizing geometric optics and the S-parameter inversion method,we design a GRIN metalens consisting of two distinct types of subwavelength unit cells(Y-shaped and circular hole geometries)with a minimum feature size of 160μm.Through a refined slurry formulation and precise design parameter compensation,high-fidelity ceramic GRIN metalenses are successfully fabricated.The fabricated metalens exhibits a maximum gain enhancement of 18.4 dBi and a deflection angle of±30°over a bandwidth of 37.84% in the W-band(75-110 GHz).The highly directional far-field beam radiation and efficient beam steering capabilities highlight the potential of ceramic GRIN metalenses for applications in satellite communications,radar systems,and other high-frequency technologies.
基金Project supported by the National Natural Science Foundation of China(Grant No.12175107)the Qing Lan Project of Jiangsu Province+2 种基金the Hua Li Talents Program of Nanjing University of PostsTelecommunications,Natural Science Foundation of Nanjing Vocational University of Industry Technology(Grant No.YK22-02-08)the Fund from the Research Center of Industrial Perception and Intelligent Manufacturing Equipment Engineering of Jiangsu Province,China(Grant No.ZK21-05-09)。
文摘Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.
基金support by National Natural Science Foundation of China (Nos. 51606158, 12104402)
文摘Fiber-optic sensing technology has the advantages of passivity, anti-electromagnetic interference, longdistancemeasurement, high sensitivity and high accuracy, small size, and adaptability to harsh environments such ashigh-vacuum, high-pressure, and strong magnetic fields compared with the traditional electrical sensing technology.However, with the increasing application requirements, how to further improve the sensitivity of fiber-optic sensors,extend the detection limit and improve the maintenance-free capability has become one of the core issues of thecurrent research. This paper reviews the principle, preparation, and application of fiber-optic microstructured sensingbased on abrupt field type. It specifically outlines the development and applications of micro-nano optical fibers,photonic crystal optical fibers, optical fiber gratings and structured optical fibers, and lists the main preparationmethods of two types of micro-nano optical fibers from the basic theory of optical fiber microstructured sensordevices.
基金Natural Science Foundation of Fujian Province(No.2024J011611)Natural Science Foundation of Nanping City(No.N2021J020)。
文摘AIM:To evaluate the visual function and optical quality in adults aged 80y and older following the bilateral implantation of zonal refractive multifocal intraocular lens(IOL,LS-313 MF30).METHODS:A single-center,non-randomized,prospective clinical trial was conducted,involving cataract patients aged 80 y and older.Patients received bilateral implantation of the LS-313 MF30 or CT Asphina 409MP,based on personal preference.Postoperative assessments included uncorrected and corrected visual acuity at distance,intermediate,and near ranges,as well as defocus curve.Subjective evaluations were performed using the visual function(VF-14)questionnaire,spectacle independence rates,and patient satisfaction surveys.Photic phenomena such as glare,halos,and starbursts were also analyzed.RESULTS:The MF30 group(16 eyes from 8 participants,85.38±2.56 y)exhibited superior uncorrected and corrected intermediate and near visual acuity compared to the 409MP group(26 eyes from 13 participants,85.77±2.20 y),while distance visual acuity was comparable between groups.The defocus curve of the MF30 group revealed two peaks at 0.00 D and-3.00 D,indicating a broader depth of focus.Patients in the MF30 group reported higher rates of spectacle independence and greater satisfaction.While photic phenomena such as glare(28.6%vs 18.5%,P=0.584),starburst(9.5%vs 3.7%,P=0.567)and halos(23.8%vs 11.11%,P=0.438)were more prevalent in the MF30 group,they were generally mild and did not significantly impact daily activities.CONCLUSION:Zonal refractive multifocal IOLs provide elderly patients with improved distance and near vision,greater spectacle independence,and greater satisfaction.Although photic phenomena were slightly more frequent with MF30,they are generally reported as non-disruptive and do not affect their daily life compared to monofocal IOLs.
基金supported by China-Russia Government to Government Scientific and Technical Cooperation Foundation (No.2007DFR70070).
文摘Traditional methods of residual stress measurement are generally destructive or semi-destructive, as well as expensive, time-consuming and complex to implement. With the new development of welded structure, traditional methods can not satisfy the need of full life task management. So the acoustical theory is introduced, since the ultrasonic technique provides a useful nondestructive tool in the evaluation of stresses. In this study an ultrasonic stress measurement experimental installation is established, which consists of a special transducer, a signal emission unit and a signal recipient processing unit. Longitudinal critically refracted wave is selected as the measurement wave mode. The supporting software is programmed by Labview software. The longitudinal residual stress and transverse residual stress of twin wire welded plate are measured by this installment, in which the measuring process is real-time, quick and nondestructive. The experiment results indicate that the system can satisfy the need of life evaluation for welded structure. The system is light and portable.
基金supported by the National Basic ResearchDevelopment (973) Program of China (Grant No. 2012CB955903)+1 种基金the National Natural Science Foundation of China (Grant No. 20907047 and Grant No. 71373131)National Industry-specific Topics (Grant No.GYHY 201406078)
文摘This paper presents a novel approach for assessing the precision of the wet refractivity field using BDS （BeiDou navigation satellite system） simulations only,GPS,and BDS＋GPS for the Shenzhen and Hongkong GNSS network.The simulations are carried out by adding artificial noise to a real observation dataset.Instead of using the δ and σ parameters computed from slant wet delay,as in previous studies,we employ the Bias and RMS parameters,computed from the tomography results of total voxels,in order to obtain a more direct and comprehensive evaluation of the precision of the refractivity field determination.The results show that：（1） the precision of tropospheric wet refractivity estimated using BDS alone （only 9 satellites used） is basically comparable to that of GPS; （2） BDS＋GPS （as of current operation） may not be able to significantly improve the data＇s spatial density for the application of refractivity tomography; and （3） any slight increase in the precision of refractivity tomography,particularly in the lower atmosphere,bears great significance for any applications dependent on the Chinese operational meteorological service.
基金Spanish Ministry of Education and Science(No.DPI2008-06455-C02-01)European Union and the Spanish Agency for International Cooperation(AECI)(No.D/030286/10)
文摘AIM:To evaluate the accuracy of spherical equivalent(SE) estimates of a double-pass system and to compare it with retinoscopy,subjective refraction and a table mounted autorefractor.METHODS:Non-cycloplegic refraction was performed on 125 eyes of 65 healthy adults(age 23.5±3.0 years) from October 2010 to January 2011 using retinoscopy,subjective refraction,autorefraction(Auto kerato refractometer TOPCON KR-8100,Japan) and a double pass system(Optical Quality Analysis System,OQAS,Visiometrics S.L.,Spain).Nine consecutive measurements with the double-pass system were performed on a subgroup of 22 eyes to assess repeatability.To evaluate the trueness of the OQAS instrument,the SE laboratory bias between the double pass system and the other techniques was calculated.RESULTS:The SE mean coefficient of repeatability obtained was 0.22D.Significant correlations could be established between the OQAS and the SE obtained with retinoscopy(r=0.956,P【0.001),subjective refraction(r=0.955,P【0.001) and autorefraction(r=0.957,P【0.001).The differences in SE between the double-pass system and the other techniques were significant(P【0.001),but lacked clinical relevance except for retinoscopy;Retinoscopy gave more hyperopic values than the double-pass system-0.51±0.50D as well as the subjective refraction-0.23±0.50D;More myopic values were achieved by means of autorefraction 0.24±0.49D. CONCLUSION:The double-pass system provides accurate and reliable estimates of the SE that can be used for clinical studies.This technique can determine the correct focus position to assess the ocular optical quality.However,it has a relatively small measuring range in comparison with autorefractors(-8.00 to +5.00D),and requires prior information on the refractive state of the patient.
基金supported by the National Basic Research Program of China(Grant Nos.2010CB327803 and 2012CB921504)the National Natural Science Foundation of China(Grant Nos.11174138,11174139,11222442,81127901,and 11274168)+1 种基金NCET-12-0254the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘We present a detailed theoretical description of wave propagation in an acoustic gradient-index system with cylindrical symmetry and demonstrate its potential to numerically control acoustic waves in different ways.The trajectory of an acoustic wave within the system is derived by employing the theory of geometric acoustics,and the validity of the theoretical descriptions is verified numerically by using the finite element method simulation.The results show that by tailoring the distribution function of the refractive index,the proposed system can yield a tunable manipulation of acoustic waves,such as acoustic bending,trapping,and absorbing.
基金Funded by the National Natural Science Foundation of China (No.60677015)the Tackling Key Project of Science and Technology Department of Zhejiang Province (No. 2007C21122)+1 种基金the Natural Science Foundation of Ningbo (No. 2006A610020)sponsored by K C Wong Magna Fund in NingBo University
文摘The glass forming region of Bi2O3-B2O3-BaO ternary system was investigated. A serial of glass samples with high Bi2O3 content in Bi2O3-B2O3-BaO system were prepared by using conventional melting and quenching meld, and the refractive indexes and absorption spectra of samples were measured. It is found that the refractive index of samples as well as the UV absorption increase with the increase of BaO content. According to the Tauc law, optical band gap Eopg which is assumed to be the effective energy band gap Eg is calculated and decreases with the increasing BaO content, and the ratio of Eg/Eopg is 1.3.
文摘The problems involving scattering and refracting of plane strain wave by a cylinder in fluidsaturated soils are studied in this paper. The theoretical solutions for the amplitudes of scattering and refracting are derived on the basis of modified Biot′s theory for twophase medium in engineering, in which the compressibility of soil grains and the viscous coupling effect between the skeletal frame and the pore fluid are taken into account. Moreover, the amplitude equations of potential function are presented when the fluidsaturated soil cylindrical inclusion is degenerated into cylindrical cavity, rigid cylinder, single phase elastic cylinder and single phase fluid cylinder.
基金supported by the Higher Education Commission,Islamabad,Pakistan in the form of an Indigenous PhD Fellowship Phase-IV to Zafarullah Khan Marwat.Zafarullah Khan Marwat is also grateful to the Higher Education Department(Colleges)Peshawar Khyber Pakhtunkhwa for grant of study leave for PhD Studies
文摘The influence of solvent on the miscibility of polystyrene（PS） and poly（styrene-co-acrylonitrile）（PSAN） blends has been investigated viscometrically. The miscibility of different PS/PSAN blend（30/70, 50/50 and 70/30） compositions in acetone and benzene at 20, 30, and 40 °C was investigated on the basis of the sign of Chee（ΔB and ）, and Sun’s（α） criteria. The values of these parameters were evaluated from the analyses of reduced viscosity data of binary（solvent/polymer） and ternary（solvent/polymer1/polymer2） polymer systems. These investigations indicated partial miscibility for both the blend systems. However, PS/PSAN/acetone blend system showed somewhat higher partial miscibility than the PS/PSAN/Benzene blend system highlighting the impact of solvent over the polymer-polymer interactions and hence their miscibility. The results obtained through viscometry were also corroborated by the refractive index and density results for the blends under study. The effect of temperature on miscibility in both the cases was almost negligible.
基金Project supported by the National Natural Science Fundation of China(Grant No.90922007)
文摘Dynamic nonlinearities of C70/toluene solution are measured and analysed by an improved picosecond timeresolved pump-probe system based on a nonlinear imaging technique with phase object. The photophysical parameters are determined by the five-level model, which is adopted to interpret the experimental data. The change of refraction index per unit density of the excited state obtained by a numerically simulation is a critical factor to determine the nonlinear behaviour of C70 in picosecond time regime.
