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Improved organic pollutants removal and simultaneous electricity production via integrating Fenton process and dual rotating disk photocatalytic fuel cell system using bamboo charcoal cathode
摘要： A coupling system combining Fenton process with dual rotating disk photocatalytic fuel cell (PFC) was developed to improve methyl orange (MO) removal and simultaneous electricity production, in which the (NH4)3PO4 modified bamboo charcoal (BC) was acted as cathode catalyst. Due to the existence of the N and P containing functional groups on the BC catalyst and the rotating electrode, the hybrid system could efficiently reduce oxygen to generate some hydroxyl radical and related species for MO removal. Therefore, Fenton-PFC-BC with rotation system showed a superior MO removal efficiency of 85%, 2.4 times higher than that in the traditional Fenton-PFC-Pt with aeration system. The radicals inhibition assays and hydrogen peroxide quantitative studies revealed that HO%, h+ and %O2- were primarily responsible for MO degradation. Furthermore, the MO removal performance for Fenton-PFC-BC with rotation system was investigated at different parameters (such as rotating speed, BC loading, pH and ferrous ion concentration) to obtain optimal operation conditions. Results of energy analysis and reusability experiment showed that the proposed Fenton-PFC-BC with rotation system provided a cost-effective and stable method for the organic degradation and energy recovery.
关键词： Bamboo charcoal,Fenton,Dual rotating disk photocatalytic fuel cell
更新于2025-09-23 15:23:52
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Ultrashort Impulse Radiation from Plane Disk with Uniform Current Distribution
摘要： The problem of transient radiation from plane disk with uniform current distribution solved by Evolutionary Equation method in Time Domain. The solution for all components of electromagnetic field is received by means of Riemann function method for Klein-Gordon equation for time dependence of current in form of Heaviside function. Using Duhamel integral the generalization of the solution for arbitrary time dependence is obtained. Amplitude and energy characteristics of radiated field are investigated for different observation distances and angles as well as time shapes of exciting current. The solution for an arbitrary time dependence of plane disk radiation is used to investigate the applicability of impulse radiation in radio communication and radar problems.
关键词： plane disk radiation,impulse communication,time domain,ultrawideband ultrashort pulse (UWB-SP),Duhamel integral,electromagnetic missile
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - The Quasi-Fractal Microstrip Antenna
摘要： The results of study of integral characteristics of quasi-fractal circular-patch monopole antennas are presented. They are obtained by using the Finite Element Method (FEM). The spectral characteristics, matching characteristics with external circuits, the pattern characteristics are presented. The results obtained show that quasi-fractal monopole microstrip resonators can be successfully used to provide the necessary integral parameters and to form the required parameters of radiated fields.
关键词： fractal,disk monopole,pattern characteristic,microstrip,spectrum
更新于2025-09-23 15:21:21
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Retinal Nerve Fiber Layer Measures and Cognitive Function in the EPIC-Norfolk Cohort Study
摘要： PURPOSE. We examined the relationship between retinal nerve fiber layer (RNFL) thickness and cognitive function in a population of older British adults. METHODS. Participants of the European Prospective Investigation of Cancer (EPIC) Norfolk cohort study underwent ophthalmic and cognitive assessment. Measurements of RNFL thickness were made using the Heidelberg Retina Tomograph (HRT). Cognitive testing included a short form of the Mini-Mental State Examination (SF-MMSE), an animal naming task, a letter cancellation task, the Hopkins Verbal Learning Test (HVLT), the National Adult Reading Test (NART), and the Paired Associates Learning Test. Multivariable linear regression models were used to assess associations of RNFL thickness with cognitive test scores, adjusted for age, sex, education level, social class, visual acuity, axial length, and history of cataract surgery. RESULTS. Data were available from 5563 participants with a mean age of 67 years. A thicker HRT-derived RNFL thickness was associated with better scores for the SF-MMSE (0.06; 95% confidence interval [CI], [0.02, 0.10], P ? 0.005), HVLT (0.16, 95% CI [0.03, 0.29]; P ? 0.014), and NART ((cid:2)0.24, 95% CI [(cid:2)0.46, (cid:2)0.02], P ? 0.035). The associations of RNFL thickness with SF-MMSE and HVLT remained significant following further adjustment for NART. CONCLUSIONS. We found a significant association between HRT-derived RNFL thickness and scores from cognitive tests assessing global function, recognition, learning, episodic memory, and premorbid intelligence. However, the associations were weak and not currently of predictive value. Further research is required to confirm and clarify the nature of these associations, and identify biological mechanisms.
关键词： epidemiology,retina,cognition,optic disk,biological markers
更新于2025-09-23 15:21:01
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Green Higha??Power Disk Lasers and Industrial Applications
摘要： In the publicly-funded ProLasKu project, the laser manufacturer Trumpf has developed a high-power laser with a wavelength of 515 nm. Substantial progress in the industrial applications of green lasers has been achieved in a cooperation between the Technical University of Munich and the companies Siemens and Continental. In addition, a camera-based system for process monitoring and quality assurance in real-time based on image processing methods has been developed.
关键词： green high-power disk lasers,industrial applications,copper,laser beam welding,process efficiency
更新于2025-09-23 15:21:01
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Near-infrared scattered light properties of the HR?4796?A dust ring
摘要： Context. HR 4796 A is surrounded by a debris disc, observed in scattered light as an inclined ring with a high surface brightness. Past observations have raised several questions. First, a strong brightness asymmetry detected in polarised re?ected light has recently challenged our understanding of scattering by the dust particles in this system. Secondly, the morphology of the ring strongly suggests the presence of planets, although no planets have been detected to date. Aims. We aim here at measuring with high accuracy the morphology and photometry of the ring in scattered light, in order to derive the phase function of the dust and constrain its near-infrared spectral properties. We also want to constrain the presence of planets and set improved constraints on the origin of the observed ring morphology. Methods. We obtained high-angular resolution coronagraphic images of the circumstellar environment around HR 4796 A with VLT/SPHERE during the commissioning of the instrument in May 2014 and during guaranteed-time observations in February 2015. The observations reveal for the ?rst time the entire ring of dust, including the semi-minor axis that was previously hidden either behind the coronagraphic spot or in the speckle noise. Results. We determine empirically the scattering phase function of the dust in the H band from 13.6? to 166.6?. It shows a prominent peak of forward scattering, never detected before, for scattering angles below 30?. We analyse the re?ectance spectra of the disc from the 0.95 μm to 1.6 μm, con?rming the red colour of the dust, and derive detection limits on the presence of planetary mass objects. Conclusions. We con?rm which side of the disc is inclined towards the Earth. The analysis of the phase function, especially below 45?, suggests that the dust population is dominated by particles much larger than the observation wavelength, of about 20 μm. Compact Mie grains of this size are incompatible with the spectral energy distribution of the disc, however the observed rise in scattering e?ciency beyond 50? points towards aggregates which could reconcile both observables. We do not detect companions orbiting the star, but our high-contrast observations provide the most stringent constraints yet on the presence of planets responsible for the morphology of the dust.
关键词： planets and satellites: detection,planetary systems,scattering,instrumentation: high angular resolution,planet-disk interactions
更新于2025-09-23 15:21:01
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Mixed Oblique Derivative Problem for the Helmholtz Equation in a Half-Disk
摘要： A mixed oblique derivative boundary value problem is considered for the Helmholtz equation in a half-disk. We prove the unique solvability of this problem for sufficiently large values of the parameter occurring in the equation, the leading part of the inverse operator being constructed explicitly.
关键词： unique solvability,mixed oblique derivative problem,half-disk,Helmholtz equation
更新于2025-09-23 15:21:01
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Handbook of Exoplanets || HR8799: Imaging a System of Exoplanets
摘要： The HR 8799 planetary system is the most intriguing and spectacular system yet discovered by direct imaging. With four gas giant planets (5–7 MJ up) orbiting at wide separations (15–70 AU) from an unusual, young A star, HR 8799 serves as a Rosetta Stone for atmospheric and planet formation physics. With direct access to the light from the planets themselves, extensive photometric and spectroscopic studies of the system have been undertaken, painting a fascinating picture of cloud formation, nonequilibrium chemistry, and potential elemental abundance measurements that can constrain formation pathways. The dynamical structure of the system is complex, with the four massive planets likely stabilized through participation in mean-motion resonances. Two belts of debris flank the planets, with a warm belt analogous to the solar system asteroid belt and a wide, cold ring comparable to the Kuiper belt. HR 8799 will continue to be studied extensively from the ground and space in the coming years, with the exciting possibility that additional planets remain to be discovered in the system.
关键词： spectroscopy,exoplanets,dynamics,system architecture,planetary system,HR 8799,photometry,direct imaging,debris disk,atmospheric properties
更新于2025-09-23 15:21:01
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High-power operation of double-pass pumped Nd:YVO <sub/>4</sub> thin disk laser
摘要： A simple, compact, double-pass pumped Nd:YVO4 thin disk laser is demonstrated. Its continuous-wave performance with different Nd doping concentrations and thicknesses is investigated experimentally. The maximum output power of 17.7 W is achieved by employing a 0.5 at.% doped sample, corresponding to an optical-to-optical ef?ciency of 46% with respect to the absorbed pump power. In addition, a numerical analysis and an experimental study of the temperature distribution, and thermal lens effect of the Nd:YVO4 thin disk, are presented considering the in?uence of the energy transfer upconversion effect and the temperature dependence of the thermal conductivity tensor. The simulated results are in good agreement with the experimental results.
关键词： energy transfer upconversion effect,Nd:YVO4,thin disk laser,thermal lens effect
更新于2025-09-23 15:19:57
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Ytterbium laser system for studying parametric amplification of femtosecond pulses with a centre wavelength of a??2 ??m
摘要： A laser system is developed with an optical synchronisation of a femtosecond signal with a pump channel. The signal of a driving ytterbium fibre laser with a 60 MHz repetition rate of stretched femtosecond pulses is amplified in energy from several nanojoules to 0.4 mJ at a pulse repetition rate of 3 kHz in a wide-band amplifier and then is compressed in time to 250 fs. The obtained radiation is used for generating femtosecond laser pulses with a centre wavelength of ~2 mm, pulse energy of above 20 mJ, duration of several field oscillations, and phase stabilisation between the electromagnetic field and envelope. The other pulse of the driving fibre laser provides optical synchronisation and a minimal time delay and is directed to a regenerative Yb : YAG disk amplifier for amplification to an energy of 4 mJ at a pulse repetition rate of 3 kHz and duration of 20 ps. A multipass disk amplifier is developed for further increasing the energy of pump chirped pulses to an energy of 70 mJ at a pulse repetition rate of 10 Hz and duration of 400 ps for studying parametric amplification under sub-nanosecond pumping.
关键词： parametric amplification,Yb :YAG disk amplifier,ytterbium fibre laser,femtosecond pulses,pulse compression
更新于2025-09-23 15:19:57