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oe1(光电查) - 科学论文

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出版时间
  • 2019
  • 2017
研究主题
  • Phased-array
  • Ultrasound-guided high-intensity focused ultrasound (USgHIFU)
  • Targeting accuracy
  • Calibration
  • cryostat
  • low intensity low temperature
  • space solar cells
  • LILT
  • solar cell characterization
  • FSO Communication System
应用领域
  • Optoelectronic Information Science and Engineering
  • Electrical Engineering and Automation
机构单位
  • Galgotias College of Engineering and Technology
  • Shanghai Jiao Tong University
  • Fraunhofer Institute for Solar Energy Systems ISE
270 条数据
?? 中文（中国） ▾

  • ultra-fine tuning

    摘要： Researchers from Xi’an University of Technology in China, alongside researchers from the ENSEIRB and the IERF in France, propose an auto-tuning network for a phased-array high intensity focused ultrasound (HIFU) system based on a variable synchronous switched capacitor. The novel system is capable of automatically compensating for the reactive power and impedance drifts, caused by temperature fluctuations and manufacturing errors, in circuit transducers and complies with magnetic resonance imaging (MRI) compatibility regulations.

    关键词： phased-array,variable synchronous switched capacitor,high-intensity focused ultrasound,HIFU,Auto-tuning network,MRI compatibility

    更新于2025-09-23 15:21:01

  • Image quality assessment method based on relation intensity and details similarity

    摘要： In this paper, we present an e?ective quality assessment method based on the relation intensity ratio and detail similarity for image quality assessment (IQA) with the full reference image, which ?rst allows us to compute the nonlinear gradient magnitude with Gaussian smoothing of the reference and distorted images and construct the relation intensity ratio and detail similarity between them. Next, the ?nal IQA map is formed by linearly combining the relation intensity ratio with the detail similarity. Finally, we adopt a new pooling strategy which e?ectively integrates the mean and standard deviation of the ?nal IQA map to accurately predict image quality. Experiments based on two publicly available databases show that the proposed method can provide accurate predictions compared with most state-of-the-art IQA methods.

    关键词： detail similarity,relation intensity ratio,Image quality assessment

    更新于2025-09-23 15:21:01

  • Optical thermometry through infrared excited green upconversion of KLa(MoO4)2:Yb3+/Er3+ Phosphor

    摘要： A series of KLa(MoO4)2:Yb3+/Er3+ phosphor was synthesized by a simple hydrothermal method. Under the excitation of 980 nm laser, the phosphor show intense green bands peaked at 525 and 550 nm and a negligible 658 nm red emission (4F9/2→4I15/2), respectively. The optical temperature sensing properties of the phosphor through the fluorescence intensity ratio (FIR) method were discussed by analyzing intensities ratio of 2H11/2 and 4S3/2 emission around the range of 303–423 K. The maximum sensor sensitivity derived from the FIR of the upconversion(UC) green emissions was approximately 0.0105 K-1. This indicates that the phosphor can be used as an excellent material for optical temperature sensing.

    关键词： fluorescence intensity ratio,upconversion,optical temperature sensing

    更新于2025-09-23 15:21:01

  • Accurate measurements of line strengths and air-broadening coefficients in methane around 1.66?μm using cavity ring down spectroscopy

    摘要： Accurate measurements of line strengths and air-broadening coefficients for 10 lines of 12CH4 mostly from the band (2ν2 + ν3) and 2 lines of 13CH4 from the band (2ν3) around 1.66 μm were performed using cavity ring down spectroscopy. Spectra of mixtures of 12CH4 in air with well-defined mole fractions of methane were recorded at pressures between 10 and 90 mbar at 296 K. The values of the line strength for 12CH4 lines were obtained with the uncertainty 1% and 2%, respectively. The uncertainties of the values of the air-broadening coefficient varied from 2 to 5% depending on the line. The values of the line strength and air-broadening coefficient for two methane isotopes obtained in this work were compared with the corresponding values from different experimental studies, as well as with the data given in HITRAN 2016 database.

    关键词： Line intensity measurements,Cavity ring down spectroscopy,Methane,Infrared,Air-broadening coefficients

    更新于2025-09-23 15:21:01

  • Interventional Oncology (Principles and Practice of Image-Guided Cancer Therapy) || Principles of high-intensity focused ultrasound

    摘要： High-intensity focused ultrasound (HIFU), also known as focused ultrasound (US), is a non-invasive image-guided therapy which has been primarily employed in the clinical realm for non-invasive thermal ablation of benign and malignant neoplasms. Real-time imaging guidance, treatment monitoring, and therapy control are achieved with either US or magnetic resonance imaging (MRI) guidance. HIFU clinical experience has been described in the treatment of leiomyomata (uterine fibroids), prostate (benign prostatic hypertrophy and cancer), breast, hepatic, renal, pancreatic, brain, and bone tumors, although for most of these tumors, relatively small numbers of treated patients have been described and widespread adoption of HIFU thermoablation remains limited. Ongoing technical challenges include the feasibility of treating large tumors within a finite treatment time, treating tumors prone to motion, and accessing targets when the acoustic window is restricted by intervening anatomy (e.g., ribs, bowel).

    关键词： image-guided therapy,thermal ablation,HIFU,High-intensity focused ultrasound,non-invasive therapy

    更新于2025-09-23 15:21:01

  • Short-Term Efficacy Comparison of High-Intensity and Low-Intensity Laser Therapy in the Treatment of Lateral Epicondylitis: A Randomized Double-Blind Clinical Study

    摘要： Objectives: This study aims to evaluate and compare the short-term efficacies of high-intensity laser therapy (HILT) and low-intensity laser therapy (LILT) in the treatment of lateral epicondylitis (LE). Patients and methods: Sixty patients (16 males, 44 females; mean age 44.2±9.3 years; range, 18 to 65 years) with unilateral elbow pain were randomized into two groups as 30 patients treated with HILT (9 males and 21 females) and 30 patients treated with LILT (7 males and 23 females). The HILT (1,064 nm) and LILT (904 nm) were administered three times a week for three weeks, and each treatment was combined with an epicondylitis bandage. A visual analog scale (VAS), quick Disabilities of the Arm, Shoulder, and Hand (QDASH) questionnaire, Medical Outcomes Study Questionnaire Short Form 36 Health Survey (SF-36), and hand grip strength test were used to evaluate the patients before and three weeks after treatment. Results: The two groups had similar demographic characteristics, including age, sex, occupation, and body mass index (p>0.05). There were no statistically significant differences between the two groups in terms of the pretreatment VAS, QDASH, hand grip strength, and SF-36 scores (p>0.05). After three weeks, both groups showed significant improvements in all of the parameters (p<0.05). However, in the HILT group, the QDASH, hand grip strength, and SF-36 physical component summary (PCS) scores showed superior improvement compared to the LILT group (p<0.05). Conclusion: Each treatment modality was found to be effective and safe for the short-term treatment of LE. However, the HILT exhibited more significant effects on the hand grip strength, QDASH, and SF-36 PCS scores than the LILT.

    关键词： Hand grip strength,low-intensity laser therapy,pain,high-intensity laser therapy,lateral epicondylitis

    更新于2025-09-23 15:19:57

  • Raman and infrared spectroscopic quantification of the carbonate concentration in K2CO3 aqueous solutions with water as an internal standard

    摘要： Carbonate-bearing fluids widely exist in different geological settings, and play important roles in transporting some elements such as the rare earth elements. They may be trapped as large or small fluid inclusions (with the size down to <1 μm sometimes), and record critical physical-chemical signals for the formations of their host minerals. Spectroscopic methods like Raman spectroscopy and infrared spectroscopy have been proposed as effective methods to quantify the carbonate concentrations of these fluid inclusions. Although they have some great technical advantages over the conventional microthermometry method, there are still some technical difficulties to overcome before they can be routinely used to solve relevant geological problems. The typical limitations include their interlaboratory difference and poor performance on micro fluid inclusions. This study prepared standard ion-distilled water and K2CO3 aqueous solutions at different molarities (from 0.5 to 5.5 mol/L), measured densities, collected Raman and infrared spectra, and explored correlations between the K2CO3 molarity and the spectroscopic features at ambient P-T conditions. The result confirms that the Raman O-H stretching mode can be used as an internal standard to determine the carbonate concentrations despite some significant differences among the correlations, established in different laboratories, between the relative Raman intensity of the C-O symmetric stretching mode and that of the O-H stretching mode. It further reveals that the interlaboratory difference can be readily removed by performing one high-quality calibration experiment, provided that later quantifying analyses are conducted using the same Raman spectrometer with the same analytical conditions. Our infrared absorption data were collected from thin fluid films (thickness less than ~2 μm) formed by pressing the prepared solutions in a Microcompression Cell with two diamond-II plates. The data show that both the O-H stretching mode and the O-H bending mode can be used as internal standards to determine the carbonate concentrations. Since the IR signals of the C-O antisymmetric stretching vibration of the CO3 2- ion, and the O-H stretching and bending vibrations from our thin films are very strong, their relative IR absorbance intensity, if well calibrated, can be used to investigate the micron-sized carbonate-bearing aqueous fluid inclusions. This study establishes the first calibration of this kind, which may have some applications. Additionally, our spectroscopic data suggest that as the K2CO3 concentration increases the aqueous solution forms more large water molecule clusters via more intense hydrogen-bonding. This process may significantly alter the physical and chemical behavior of the fluids.

    关键词： Relative IR absorbance,K2CO3 concentration,Relative Raman intensity,Carbonate aqueous solution,Micro fluid inclusion

    更新于2025-09-23 15:19:57

  • Influence of target curvature on the characteristics of particle beams generated by laser ion acceleration with microstructured enhanced targets at ultra high intensity

    摘要： Following the advances in laser science that have been performed recently, the push to improve the quality of the laser generated particle beams has seen a lot of interest in the past decade. The work presented in this paper aims to study the role of target curvature using 2D PIC simulations to ascertain its influence on the angular spread and peak energy for the accelerated proton beam, and the characteristics of the gamma photons produced for potential usage as secondary sources. For the scope of this work we parametrically probed different curvature radii of a microstructured enhanced target impacted by a laser pulse with predetermined parameters. This paper continues past studies (Tatomirescu et al 2017 AIP Conf. Proc. 1796 020013; Tatomirescu et al 2017 AIP Conf. Proc. 1916 030002) and concentrates on determining the target curvature effect when using conical structures for pulse focusing. The results show promising enhanced focus of the accelerated particles and an enhancement of the peak energy of the accelerated particles.

    关键词： variable target curvature,particle-in-cell,ultra high intensity laser pulse,microstructured target

    更新于2025-09-23 15:19:57

  • [IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Wavelength-selective beam deflector based on Fano-resonant metasurface

    摘要： Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.

    关键词： Photoplethysmographic image,light intensity,light spectrum,low-cost camera

    更新于2025-09-23 15:19:57

  • Generation of kinetic Alfv??n wave and whistler waves by parametric decay of high power laser in lasera??plasma interaction

    摘要： In this paper, we report theoretical modeling for parametric decay instability of the high-intensity elliptically polarized laser beam [pump wave, (x0)]. A wave–wave interaction model is investigated, based on the decay of the high-intensity elliptically polarized laser (x0) into an oblique whistler wave (OWW, ex1T) and a kinetic Alfv(cid:2)en wave (KAW, ex2T). The importance of oblique whistler waves (OWWs, ex1T) and kinetic Alfv(cid:2)en waves (KAWs, ex2T) similar to solar wind spectra [Chatterjee et al., Nat. Commun. 8, 15970 (2017)] has been pointed out, as a means to understand the turbulent magnetic ?eld ampli?cation, implicating electron and ion dynamics [Chatterjee et al., Nat. Commun. 8, 15970 (2017); Tzeferacos et al., Nat. Commun. 9, 591 (2018); Meinecke et al., Proc. Natl. Acad. Sci. 112, 8211 (2015); Mondal et al., Proc. Natl. Acad. Sci. 109, 8011 (2012); Romagnani et al., Phys. Rev. Lett. 122, 025001 (2019); Perri et al., Phys. Rev. Lett. 109, 191101 (2012); and Adak et al., Phys. Rev. Lett. 114, 115001 (2015)]. In the nonlinear stage, the decay instability is expected to attain the turbulent state, via a cascade process or ?lamentation/modulation instability (oscillating two stream instability). Therefore, in the present paper, we have considered the ?rst part of this research, namely, the beating mechanism ex2 ? x0 (cid:2) x1T, induced due to the nonlinear interaction of elliptically polarized laser velocity and oblique whistler wave density perturbation. The nonlinear saturation will be conferred in future investigations. Besides turbulence, the relevance of the present work to terahertz radiation generation [Singh et al., Europhys. Lett. 104, 35002 (2013); Dewan et al., Phys. Plasmas 25, 103105 (2018); Singh et al., Phys. Plasmas 18, 022304 (2011); M. Singh and R. P. Sharma, Contrib. Plasma Phys. 53(7), 540–548 (2013); Adak et al., Phys. Rev. Lett. 114, 115001 (2015); G. Brodin and L. Sten?o, Contrib. Plasma Phys. 54, 623 (2014); L. Sten?o, Phys. Scr. T50, 15–19 (1994); Li et al., Phys. Rev. E 84, 036405 (2011); L. Sten?o, Phys. Scr. T107, 262 (2004); and R. Boyd, Nonlinear Optics, 3rd ed. (Elsevier, 2008), Chap. 2] and fast ignition laser fusion [Kumar et al., arXiv:1804.02200 (2018)] by ion heating has been emphasized. The coef?cients for the nonlinear coupling pertaining to this parametric decay process and the growth rate of the decay instability are investigated.

    关键词： high-intensity elliptically polarized laser beam,terahertz radiation,oblique whistler wave,kinetic Alfv(cid:2)en wave,parametric decay instability,fast ignition laser fusion

    更新于2025-09-23 15:19:57