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On U_(S)-admitting Reflections of T_(0) Spaces
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作者 Liqun LIN Jinbo YANG 《Journal of Mathematical Research with Applications》 2025年第6期800-812,共13页
U_(S)-admitting spaces,which were introduced by Heckmann,enjoy many nice properties similar to those of the extensively studied well-filtered spaces.In this paper,we present a direct construction of the U_(S)-admittin... U_(S)-admitting spaces,which were introduced by Heckmann,enjoy many nice properties similar to those of the extensively studied well-filtered spaces.In this paper,we present a direct construction of the U_(S)-admitting reflections by using U_(S)-admitting determined sets. 展开更多
关键词 well-filtered space reflective subcategory sober space U_(S)-admitting space
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Total score of the computer vision syndrome questionnaire predicts refractive errors and binocular vision anomalies
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作者 Mosaad Alhassan Tasneem Samman +5 位作者 Hatoun Badukhen Muhamad Alrashed Balsam Alabdulkader Essam Almutleb Tahani Alqahtani Ali Almustanyir 《International Journal of Ophthalmology(English edition)》 2026年第1期90-96,共7页
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
关键词 computer vision syndrome refractive errors ACCOMMODATION VERGENCE binocular vision SYMPTOMS
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Metacognition Inspired Reflective Chain-of-Thought for Knowledge-Based VQA
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作者 Zhongfan Sun Kan Guo +1 位作者 Yongli Hu Yong Zhang 《Computers, Materials & Continua》 2026年第4期1909-1933,共25页
Knowledge-based VisualQuestion Answering(VQA)requires the integration of visual information with external knowledge reasoning.Existing approaches typically retrieve information from external corpora and rely on pretra... Knowledge-based VisualQuestion Answering(VQA)requires the integration of visual information with external knowledge reasoning.Existing approaches typically retrieve information from external corpora and rely on pretrained language models for reasoning.However,their performance is often hindered by the limited capabilities of retrievers and the constrained size of knowledge bases.Moreover,relying on image captions to bridge the modal gap between visual and language modalities can lead to the omission of critical visual details.To address these limitations,we propose the Reflective Chain-of-Thought(ReCoT)method,a simple yet effective framework inspired by metacognition theory.ReCoT effectively activates the reasoning capabilities ofMultimodal Large LanguageModels(MLLMs),providing essential visual and knowledge cues required to solve complex visual questions.It simulates a metacognitive reasoning process that encompasses monitoring,reflection,and correction.Specifically,in the initial generation stage,an MLLM produces a preliminary answer that serves as the model’s initial cognitive output.During the reflective reasoning stage,this answer is critically examined to generate a reflective rationale that integrates key visual evidence and relevant knowledge.In the final refinement stage,a smaller language model leverages this rationale to revise the initial prediction,resulting in amore accurate final answer.By harnessing the strengths ofMLLMs in visual and knowledge grounding,ReCoT enables smaller language models to reason effectively without dependence on image captions or external knowledge bases.Experimental results demonstrate that ReCoT achieves substantial performance improvements,outperforming state-of-the-art methods by 2.26%on OK-VQA and 5.8%on A-OKVQA. 展开更多
关键词 Knowledge-based VQA METACOGNITION reflective chain-of-thought answer refinement
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Postoperative effective lens position and refraction changes with three different types of intraocular lens
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作者 Xi-Xia Ding Lin-Feng Xiang +5 位作者 Wen-Tao Tong Dan-Dan Wang Hong-FangZhang Ping-Jun Chang Fu-Man Yang Yun-E Zhao 《International Journal of Ophthalmology(English edition)》 2026年第2期260-265,共6页
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
关键词 effective lens position refractION intraocular lens swept-source optical coherence tomography
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Highly sensitive,multi-stage,and mid-infrared refractive index sensor based on photonic spin Hall effect
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作者 Jiaye Ding Chenglong Wang +2 位作者 Shengli Liu Peng Dong Jie Cheng 《Chinese Physics B》 2026年第1期432-438,共7页
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
关键词 refractive index(RI)sensor photonic spin Hall effect MID-IR MULTI-STAGE
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Quantifying the impact of dust retention on maize canopy spectral reflectance and vegetation indices in dust belt regions:A case study in southern Xinjiang,China
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作者 MA Baodong GAO Shuxian +2 位作者 KANG Ting CHE Defu SHU Yang 《Journal of Arid Land》 2026年第1期101-130,共30页
Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance... Sand dust belts span approximately one-fifth of the global land surface.In these regions,dust tends to settle on vegetation surfaces,altering the observed reflectance and affecting remote sensing detections.To enhance the accuracy of maize growth monitoring in dust-affected regions,this study aims to quantify the effect of sand dust retention on maize during the tasseling stage in the Kashgar Prefecture,Xinjiang Uygur Autonomous Region,China,by analyzing changes in canopy reflectance and vegetation indices.First,field sampling was conducted to measure the key canopy structure parameters and dust retention levels of maize,and laboratory spectral measurements were performed on leaf spectral properties under gradient dust retention.The measured data were then used to drive the LargE-Scale remote sensing data and image Simulation framework(LESS)model for simulating realistic maize canopy spectra across different dust levels,with validation against Sentinel-2 imagery.Second,on the basis of the simulated and satellite-derived spectra,the dust resistance of 36 common vegetation indices was systematically evaluated,and new robust dust-resistant indices were developed.The results showed that compared with dust-free maize,the canopy reflectance of dust-retained maize followed an increase–decrease–increase pattern,with critical turning points at 735 and 1325 nm.The maximum reflectance difference of–0.11755(change rate:29.002%)occurred within the 735–1325 nm range at 24 g/m^(2)dust retention,and the minimum reflectance difference of 0.04285(change rate:148.950%)was observed in the 350–735 nm range under the same dust retention level.Among the 36 vegetation indices,only the global environment monitoring index(GEMI)and the ratio of transformed chlorophyll absorption in reflectance index to optimized soil-adjusted vegetation index(TCARI/OSAVI)exhibited dust resistance,with GEMI being effective below 6 g/m^(2)and TCARI/OSAVI remaining stable across all levels(average ratio:0.970).The newly developed indices in this study,(RE3–RE2)/(NIR–RE2),(RE3–RE2)/(RE4–RE2),and(NIR–RE2)/(RE4–RE2),retained values within the predefined dust-resistant range over the full dust retention levels of 0–24 g/m^(2),thus showing a more stable dust resistance compared with the commonly used 36 vegetation indices.Specially,(RE3–RE2)/(RE4–RE2)performed the most robustly in Sentinel-2 imagery,that is,58.020%of pixels were within the dust-resistant range,and an average ratio of 0.937 was obtained for the original-spectra index.This study provides a scientific basis for crop monitoring and management in dust-affected regions. 展开更多
关键词 sand dust retention canopy spectral reflectance LargE-Scale remote sensing data and image Simulation framework(LESS)model dust-resistant vegetation indices tasseling-stage maize Sentinel-2 imagery
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Reflections on Non-English Major Postgraduate English Teaching Reform 被引量:2
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作者 郁仲莉 《Sino-US English Teaching》 2006年第8期12-15,31,共5页
This paper presents some reflections on non-English major postgraduate English teaching reform. The author points out some understandings on the English proficiency of non-English major postgraduate students and curri... This paper presents some reflections on non-English major postgraduate English teaching reform. The author points out some understandings on the English proficiency of non-English major postgraduate students and curriculum changes in the reform. The author thinks that postgraduate English teaching reform is a systematic project, with a goal to meet the practical needs of postgraduate students and improve their ability to use English in their study and work. Hence, every effort of the reform should be made to satisfy the practical needs of the students and to make their English study contribute to their achievements in their own subject area. 展开更多
关键词 reflectION non-English major postgraduate English teaching reform
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Reflection and refraction of attenuated waves at boundary of elastic solid and porous solid saturated with two immiscible viscous fluids 被引量:4
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作者 M.KUMAR R.SAINI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2012年第6期797-816,共20页
The propagation of elastic waves is studied in a porous solid saturated with two immiscible viscous fluids. The propagation of three longitudinal waves is represented through three scalar potential functions. The lone... The propagation of elastic waves is studied in a porous solid saturated with two immiscible viscous fluids. The propagation of three longitudinal waves is represented through three scalar potential functions. The lone transverse wave is presented by a vector potential function. The displacements of particles in different phases of the aggregate are defined in terms of these potential functions. It is shown that there exist three longitudinal waves and one transverse wave. The phenomena of reflection and refraction due to longitudinal and transverse waves at a plane interface between an elastic solid half-space and a porous solid half-space saturated with two immiscible viscous fluids are investigated. For the presence of viscosity in pore-fluids, the waves refracted to the porous medium attenuate in the direction normal to the interface. The ratios of the amplitudes of the reflected and refracted waves to that of the incident wave are calculated as a non- singular system of linear algebraic equations. These amplitude ratios are used to further calculate the shares of different scattered waves in the energy of the incident wave. The modulus of the amplitude and the energy ratios with the angle of incidence are computed for a particular numerical model. The conservation of the energy across the interface is verified. The effects of variations in non-wet saturation of pores and frequencies on the energy partition are depicted graphically and discussed, 展开更多
关键词 dissipative porous solid immiscible viscous fluid elastic wave propagation attenuation reflection and refraction coefficients
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Reflection and refraction of plane waves at the boundary of an elastic solid and double-porosity dual-permeability materials 被引量:2
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作者 M.Kumar M.S.Barak M.Kumari 《Petroleum Science》 SCIE CAS CSCD 2019年第2期298-317,共20页
Phenomena of reflection and refraction of plane harmonic waves at a plane interface between an elastic solid and doubleporosity dual-permeability material are investigated. The elastic solid behaves non-dissipatively,... Phenomena of reflection and refraction of plane harmonic waves at a plane interface between an elastic solid and doubleporosity dual-permeability material are investigated. The elastic solid behaves non-dissipatively, while double-porosity dual-permeability materials behave dissipatively to wave propagation due to the presence of viscosity in pore fluids. All the waves(i.e., incident and reflected) in an elastic medium are considered as homogeneous(i.e., having the same directions of propagation and attenuation), while all the refracted waves in double-porosity dual-permeability materials are inhomogeneous(i.e., having different directions of propagation and attenuation). The coefficients of reflection and refraction for a given incident wave are obtained as a non-singular system of linear equations. The energy shares of reflected and refracted waves are obtained in the form of an energy matrix. A numerical example is considered to calculate the partition of incident energy among various reflected and refracted waves. The effect of incident direction on the partition of the incident energy is analyzed with a change in wave frequency, wave-induced fluid-flow, pore-fluid viscosity and double-porosity structure.It has been confirmed from numerical interpretation that during the reflection/refraction process, conservation of incident energy is obtained at each angle of incidence. 展开更多
关键词 Plane harmonic wave Double-porosity dual-permeability reflection/refraction coefficients Energy SHARE Elastic solid
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Reflections on Communicative Language Teaching Approach Based on Observation of Management Course
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作者 侯香勤 《大学英语教学与研究》 2014年第3期11-13,共3页
Communicative language teaching approach is effective in cultivating students' communicative competence. It has changed the way of teaching as well as learning. This paper, based on class observation of one semest... Communicative language teaching approach is effective in cultivating students' communicative competence. It has changed the way of teaching as well as learning. This paper, based on class observation of one semester's "management"course,reflects on the teaching approach employed by the teacher, discusses its benefits and problems within the class, and explores the underlying principles of the approach adopted. 展开更多
关键词 大学 英语学习 学习方法 阅读知识 阅读材料
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REFLECTION AND REFRACTION OF STRESS WAVES AT A STRUCTURAL WEAKNESS PLANE IN ROCK MASS 被引量:4
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作者 Li Xibing Lai Haihui Gu Desheng 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 1992年第1期11-18,共8页
In the case or wave interactions with structural weakness planes in rook mass the results of reflection and refraction of waves at entirely cohesive boundaries have been used all along.But,oblique incidences of compre... In the case or wave interactions with structural weakness planes in rook mass the results of reflection and refraction of waves at entirely cohesive boundaries have been used all along.But,oblique incidences of compressive stress waves at the structural weakness plane may result in relative slippage of rocks on both sides of the plane.The authors have derived the reflection and refraction coefficients for plane stress waves generated by blasting incidents on the structural weakness plane in rook mass according to its special boundary condition.The formula of energy dissipation and some computational results at the structural weakness plane are obtained.On the above basis,some problems about rook and soil engineering are discussed. 展开更多
关键词 refractION entirely OBLIQUE
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Reflections on Humanity from the Modern Vampirism 被引量:1
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作者 张志国 《海外英语》 2011年第10X期308-309,共2页
Vampirism is a very popular theme in modern novels, movies or other forms of literature genres. This paper tries to explore the development of vampirism literatures and by doing so makes some deep reflections on human... Vampirism is a very popular theme in modern novels, movies or other forms of literature genres. This paper tries to explore the development of vampirism literatures and by doing so makes some deep reflections on humanity from the modern vampirism. 展开更多
关键词 HUMANITY Vampirism reflections
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Refractive Outcomes Using the Lenstar Optical Low Coherence Reflectometry Biometer in Phacovitrectomy for Epiretrinal Membranes and Macular Holes 被引量:2
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作者 Mark A. P. Fajgenbaum Julian Robins Tom H. Williamson 《Open Journal of Ophthalmology》 2017年第3期216-224,共9页
Objective: To compare refractive outcomes using the Lenstar optical low-coherence reflectometry (OLCR) biometer in the following cases: phacovitrectomy for epiretinal membranes and macular holes (phacovitrectomy group... Objective: To compare refractive outcomes using the Lenstar optical low-coherence reflectometry (OLCR) biometer in the following cases: phacovitrectomy for epiretinal membranes and macular holes (phacovitrectomy group);sequential cataract surgery after prior vitrectomy (sequential-phaco group);routine cataract surgery (phaco-only group). Methods: This study was a retrospective, consecutive comparative series. Main outcomes were mean prediction error (ME) and mean absolute prediction error (MAE). Secondary out-come was the variance in prediction error. Results: ME was significantly more myopic in the phacovitrectomy group (-0.08 ± 0.77D, mean ± SD, p = 0.04) and the sequentialphaco group (-0.09 ± 0.51D, p = 0.01) compared to the phaco-only group (+0.24 ± 0.53D). MAEs were not statistically different across the 3 groups. The phacovitrectomy group had a wider variance in prediction errors compared to the phaco-only group (p = 0.03). Conclusions: There is a myopic shift of approximately -0.3D in both phacovitrectomy and sequential-phaco cases compared to phaco-only cases when using OLCR-based optical biometry. Phacovitrectomy outcomes are more variable compared to phaco-only eyes. 展开更多
关键词 refractive OUTCOMES Phacovitrectomy OPTICAL BIOMETRY LENSTAR OLCR
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High-accuracy self-mixing interferometer based on multiple reflections using a simple external reflecting mirror 被引量:2
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作者 WANG Xiu-lin1 WEI Zheng2 +1 位作者 WANG Rui2 HUANG Wen-cai2 《Optoelectronics Letters》 EI 2018年第3期161-163,共3页
A self-mixing interferometer(SMI)with resolution twenty times higher than that of a conventional interferometer is developed by multiple reflections.Only by employing a simple external reflecting mirror,the multiple-p... A self-mixing interferometer(SMI)with resolution twenty times higher than that of a conventional interferometer is developed by multiple reflections.Only by employing a simple external reflecting mirror,the multiple-pass optical configuration can be constructed.The advantage of the configuration is simple and easy to make the light re-injected back into the laser cavity.Theoretical analysis shows that the resolution of measurement is scalable by adjusting the number of reflections.The experiment shows that the proposed method has the optical resolution of approximateλ/40.The influence of displacement sensitivity gain(G)is further analyzed and discussed in practical experiments. 展开更多
关键词 HIGH-ACCURACY SELF-MIXING INTERFEROMETER mul-Liple reflections
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Reflections on Tools and Methods for Differentiated Assessments of Individual Scientists, Groups of Scientists and Scientific Journals 被引量:2
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作者 Ronald Rousseau Xiaolin Zhang 《Journal of Data and Information Science》 CSCD 2019年第3期1-5,共5页
Requirements for research assessments There are huge differences in mission, emphasis, inherent capability, and targeted utilization of research among scientific institutions. Hence, when it comes to assessments, a on... Requirements for research assessments There are huge differences in mission, emphasis, inherent capability, and targeted utilization of research among scientific institutions. Hence, when it comes to assessments, a one-size-fits-all approach cannot meet the goal(s) of these assessments. Probably even larger differences exist between individuals, research teams and departments. 展开更多
关键词 reflections TOOLS and METHODS DIFFERENTIATED Assessments of INDIVIDUAL Scientists
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A Free Surface Frequency Domain Green Function with Viscous Dissipation and Partial Reflections from Side Walls 被引量:2
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作者 Hongde Qin Jing Shen Xiaobo Chen 《Journal of Marine Science and Application》 2011年第3期259-264,共6页
The free-surface Green function method is widely used in solving the radiation or diffraction problems caused by a ship or ocean structure oscillating on the waves. In the context of inviscid potential flow, hydrodyna... The free-surface Green function method is widely used in solving the radiation or diffraction problems caused by a ship or ocean structure oscillating on the waves. In the context of inviscid potential flow, hydrodynamic problems such as multi-body interaction and tank side wall effect cannot be properly dealt with based on the traditional free-surface frequency domain Green function method, in which the water viscosity is omitted and the energy dissipation effect is absent. In this paper, an open-sea Green function with viscous dissipation was presented within the theory ofvisco-potential flow. Then the tank Green function with a partial reflection from the side walls in wave tanks was formulated as a formal sum of open-sea Green functions representing the infinite images between two parallel side walls of the source in the tank. The new far-field characteristics of the tank Green function is vitally important fur improving the validity of side-wall effects evaluation, which can be used in supervising the tank model tests. 展开更多
关键词 Green function viscous dissipation side wall effect partial reflection
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Characteristics of seismic reflections in central region of the South China Sea and their geological significance 被引量:1
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作者 刘建华 金翔龙 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2000年第3期103-113,共11页
More than 4 000 km 48-channel seismic reflection data from the central region of the South China Sea have been interpreted. Five seismic interfaces have been distinguished, named T1, T2, T4, T6 and Tg respectively Mea... More than 4 000 km 48-channel seismic reflection data from the central region of the South China Sea have been interpreted. Five seismic interfaces have been distinguished, named T1, T2, T4, T6 and Tg respectively Meanwhile, five seismic sequences numbered I - V have been divided with the ages of Quaternary and Pliocene, Later Mocene, Earlier and Middle Miocene, Oligocene and Pre- Oligocene separately. Sequences I-II overlie all parts of the area. In the continental slope and island slope, Sequences III-V are mainly found in the grabens. Sequence III is found at moot profiles of the deep-sea basin, and Sequnce IV is seen not only at the margins of the east subbasin but also at the margins of the southwest subbasin. Strong reflection from Moho is found at most profiles of the deep-sea basin. The depth of Moho varies between 10 and 12 km, with a thickness of 6- 8 km for the crust. Calculated by age-basement depth correlation formula, the age of basaltic basement in the southwest subbasin is 51-39 Ma. It is indicated that the evolution of the southwest subbasin is simultaneous with or earlier than that of the east subbasin. 展开更多
关键词 Central region of the South China Sea seismic reflection evolution of the back-arc basin
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Structural Characteristics of the Basement beneath Qiangtang Basin in Qinghai-Tibet Plateau: Results of Interaction Interpretation from Seismic Reflection/Refraction Data
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作者 LI Qiusheng GAO Rui +9 位作者 FENG Shaoying LU Zhanwu HOU Hesheng GUAN Ye LI Pengwu WANG Haiyan YE Zhuo XIONG Xiaosong LIU Jinkai HE Rizheng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第2期358-377,共20页
The studies on configuration, character/property of the basement of Qiangtang basin is helpful for evaluating petroleum and nature gas resources as well as understanding the basin evolvement. Recently a moderate to hi... The studies on configuration, character/property of the basement of Qiangtang basin is helpful for evaluating petroleum and nature gas resources as well as understanding the basin evolvement. Recently a moderate to high-grade metamorphic gneiss rock was found underlying beneath very low metamorphic Ordovician strata in Mayer Kangri to the north of the central uplift. That fact actually proved existence of the crystalline basement just the distribution and structures of pre-Paleozoic crystalline basement still remain puzzle. In recent years a number of active sources deep seismic profiling, to aim at lithospheric structure of northern Tibet and petroleum resources of the Qiangtang basin, had been conducted that make it possible to image the structure of the basement of the Qiangtang. Near vertical reflection profiles, included those acquired previously and those during 2004 to 2008, have been utilized in this study. By through the interaction process and interpretation between the reflection profiles and the wide-angle profile, a model with the detailed structure and velocity distribution from surface to the depth of 20 km of Qiangtang basin has been imaged.Based on the results and discussions of this study, the preliminary conclusions are as follows: (1) The velocity structure section (~20 kin) that is interactively constrained by the refraction and reflection seismic data reveals that the sedimentary stratum gently lie until 10 km in the south Qiangtang basin. (2) The basement consists of fold basement (the upper) and crystalline basement (the lower).The fold basement buried at the average depth of 6 km with a velocity of 5.2-5.8 km/s. The shallowest appear at range of the central uplift. The crystalline basement is underlying beneath the fold basement at the average depth of 10 km with a velocity of 5.9-6.0 km/s except near Bangong-Nujiang suture. (3) The high-velocity body at the depth range of 3-6 km of the central uplift is considered as a fragment of the crystalline basement that perhaps was raised by Thermal or deformation. (4) The lower-consolidated fold basement show more affinity of Yangtze block but the crystalline basement seems more approximate to Lhasa terrene in geophysical nature. We have attempted to improve the resolution and reliability by interaction of the active seismic data and prove it effective to image complex basement structure. It will be a potential to process the piggy-back acquisition data and has wide prospects. 展开更多
关键词 seismic reflection seismic refraction basement structure Qiangtang basin Qinghai-TibetPlateau
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Reflection and refraction of waves in oscillatory media
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作者 顾国锋 吕耀平 唐国宁 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第5期168-171,共4页
This paper uses the two-dimensional Brusselator model to study reflection and refraction of chemical waves. It presents some boundary conditions of chemical waves, with which occurence of observed phenomena at interfa... This paper uses the two-dimensional Brusselator model to study reflection and refraction of chemical waves. It presents some boundary conditions of chemical waves, with which occurence of observed phenomena at interface as refraction and reflection of chemical waves can be interpreted. Moreover, the angle of reflection may be calculated by using the boundary conditions. It finds that reflection and refraction of chemical waves can occur simultaneously even if plane wave goes from a medium with higher speed to a medium with lower speed, provided the incident angle is larger than the critical angle. 展开更多
关键词 reflectION refractION chemical wave
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Reflection and Refraction of Gaussian Beam on Wavy Surface in Airborne Ocean Lidar
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作者 Yang Ke-cheng,Li Yi,Zhu Xiao,Li Zai-guang National Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2002年第2期207-211,共5页
According to the statistical description of direction distribution on wavy surface by Cox, we have set up a physical model of reflection and refraction of Gaussian beam on wavy surface, derived that a beam reflected a... According to the statistical description of direction distribution on wavy surface by Cox, we have set up a physical model of reflection and refraction of Gaussian beam on wavy surface, derived that a beam reflected and refracted by wavy surface is also a Gaussian beam when the incident beam is a Gaussian beam, and set up the relationship between Gaussian beam's light spot size and wind speed over sea surface. 展开更多
关键词 Key words laser wavy water surface reflectION refractION
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