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排序方式: 共有121条查询结果,搜索用时 15 毫秒
1.
Valery Agoshkov Paola Gervasio Alfio Quarteroni 《Mediterranean Journal of Mathematics》2006,3(2):147-176
New domain decomposition methods (DDM) based on optimal control approach are introduced for the coupling of first and second
order equations on overlapping subdomains. Several cost functionals and control functions are proposed. Uniqueness and existence
results are proved for the coupled problem, and the convergence of iterative processes is analyzed.
The work was supported by the Russian Foundation for Basic Research (04-01-00615) and it was partly carried out while the
first author was visiting the IACS at EPFL. 相似文献
2.
Ultraviolet (UV) reflection in the urban constructed environment is not well understood for topical issues such as measuring and modeling the received UV exposure due to that UV reflection for outdoor workers. Both predominantly specular and diffuse reflecting surface types have been identified and investigated for the erythemal UV reflection ratio variation due to solar zenith angle and orientation. This paper presents relationships between erythemal UV reflection ratios measured for non‐horizontal and horizontal surfaces, with predominantly specular surface types indicating stronger relationships with solar zenith angles than diffuse reflecting surfaces types. Erythemal UV exposures caused by the same reflecting surface types at three inclinations are also investigated. Non‐horizontal surfaces can increase erythemal UV exposures compared to erythemal UV exposures received from the same horizontal surface by factors of 1.07–1.46 for specific body sites and by 1.01–1.70 for averages of group body sites for zinc aluminium coated steel sheeting. 相似文献
3.
Nathan J. Downs Peter W. Schouten Alfio V. Parisi 《Photochemistry and photobiology》2013,89(5):1234-1243
Fringing coral reefs provide a unique opportunity to study shallow aquatic ecosystems. A fringing coral reef system located in close proximity to a developed region was considered in this study. In such an environment, the rate of decay of dissolved organic matter is high and the penetration of higher energy ultraviolet‐B (UVB) extends a greater influence on species diversity, particularly upon shallow benthic communities. Results from a 9 month subsurface UVB exposure measurement campaign performed at a site located on the southern Queensland coast (Hervey Bay, 25°S) are presented in this research. For this, a novel dosimetric technique was utilized to measure long‐term subsurface UVB exposures. The resultant data set includes exposure measurements made during the significant La Niña event of late 2010 which resulted in unprecedented high sea surface temperatures and severe flooding across eastern Australia, impacting upon the lagoon regions of the Great Barrier Reef and Queensland's southern estuaries, including the study site. The influence of season, diurnal tidal variation, cloud cover and solar zenith angle were analyzed over the campaign period. Mean minimum daylight water depth was found to be the most significant factor influencing subsurface UVB. 相似文献
4.
Mustapha A. A. Jebar Nathan J. Downs Alfio V. Parisi Joanna Turner 《Photochemistry and photobiology》2021,97(1):192-197
This research presents a novel methodology for deriving the total daily broadband solar UVA (320–400 nm) received by school teachers during their working day from Ozone Monitoring Instrument (OMI) satellite solar noon UVA irradiance measurements for a Queensland subtropical site (27.5°S, 152°E). Daily UVA exposures are weighted to the anatomical human cheek (anterior infra‐orbital region) for teachers wearing and not wearing broad‐brimmed hats. The method utilizes the OMI UVA irradiance data collected daily at high temporal resolution over 2005 to 2016 to derive the total daily UVA exposure to a horizontal plane. These horizontal plane exposures are scaled by factors to take into account the timing of outdoor activity. The relationship between exposures to a horizontal plane and those to a vertical plane and the protection provided by a broad‐brimmed hat was assessed to evaluate the total daily UVA exposures to the cheek for classroom and physical education teaching staff expected to be outside at different periods of the day. The developed method enables the total daily UVA exposure to specific anatomical sites to be evaluated from the satellite solar noon irradiance at locations that do not have access to surface‐based instrumentation capable of recording in the solar UVA waveband. 相似文献
5.
Alfio Bonanno Giampiero Esposito Claudio Rubano Paolo Scudellaro 《General Relativity and Gravitation》2007,39(2):189-209
In the framework of renormalization-group improved cosmologies, we use the Noether symmetry approach to get exact and general
integration of the matter-dominated cosmological equations. This is performed by using an expression of Λ = Λ (G) determined by the method itself. We also work out a comparison between such a model and the concordance ΛCDM model as to
the magnitude–redshift relationship, hence showing that no appreciable differences occur. 相似文献
6.
Proton acceleration using high-intensity laser pulses, at 1016 W/cm2 was studied irradiating different types of thin metal and plastic targets having 1-micron thickness. The maximization of the proton energy process was investigated optimizing the laser parameters, the irradiation conditions and the target properties. Employing 600–700 J laser pulse energy, a focalization inducing self-focusing effects and using targets with optimized thickness, it was possible to accelerate protons up to energies of above 8 MeV. The time-of-flight diagnostics has allowed to monitor the plasma properties and to control the ion acceleration process. 相似文献
7.
In this research, the erythemally effective UV measured using miniaturized polysulphone dosimeters to over 1250 individual body sites and collected over a 4-year period is presented relative to the total exposed skin surface area (SSA) of a life-size manikin model. A new term is also introduced, the mean exposure fraction (MEF). The MEF is used to weight modeled or measured horizontal plane UV exposures to the total unprotected SSA of an individual and is defined as the ratio of exposure per unit area received by the unprotected skin surfaces of the body relative to the exposure received on a horizontal plane. The MEF has been calculated for a range of solar zenith angles (SZA) to provide a sunburning energy data set weighted to the actual SSA of a typically clothed individual. For this research, the MEF was determined as 0.15, 0.26 and 0.41 in the SZA ranges 0°-30°, 30°-50° and 50°-80° providing information that can be used in a variety of different ambient, latitudinal and seasonal climates where total human body UV exposure information is not available. 相似文献
8.
Nathan J. Downs Damien P. Igoe Alfio V. Parisi Olivia Taylor Shari L. Lazzaroni Alex Rawlings Daniel R. Garzn‐Chavez Simone L. Harrison 《Photochemistry and photobiology》2019,95(4):1083-1093
The risk of keratinocyte skin cancer, malignant melanoma and ultraviolet radiation (UVR)‐induced eye disease is disproportionately higher in Australia and New Zealand compared to equivalent northern hemisphere latitudes. While many teachers are aware of the importance of reinforcing sun safety messages to students, many may not be aware of the considerable personal exposure risk while performing outdoor duties in locations experiencing high to extreme ambient UVR year‐round. Personal erythemally effective exposure of classroom teachers in tropical Townsville (19.3°S) was measured to establish seasonal extremes in exposure behavior. Mean daily personal exposure was higher in winter (91.2 J m‐2, 0.91 Standard Erythema Dose [SED]) than summer (63.3 J m?2, 0.63 SED). The range of exposures represents personal exposures that approximate current national guidelines for Australian workers at the study latitude of approximately 1.2 SED (30 J m?2 effective to the International Commission on Non‐Ionizing Radiation Protection). Similar proportions of teachers spent more than 1 h outdoors per day in winter (28.6%) and summer (23.6%) as part of their teaching duties with seasonal differences having little effect on the time of exposure. Personal exposures for teachers peaked during both seasons near school meal break times at 11:00 am and 1:00 pm, respectively. 相似文献
9.
Giuliano Grandolini Adolfo Ricci Alfio Martani Franco Delle Monache 《Journal of heterocyclic chemistry》1966,3(3):302-310
The nuclear magnetic resonance spectra of forty-nine benzobisheterocyclic compounds, containing various heterocycles, were determined. The observed spectral data made possible the elucidation of the structure and also clarified the influences of the heterocyclic substituents and of heterocyclic rings on chemical shift values of the aromatic protons. 相似文献
10.
As part of a wider study into the use of smartphones as solar ultraviolet radiation monitors, this article characterizes the ultraviolet A (UVA; 320–400 nm) response of a consumer complementary metal oxide semiconductor (CMOS)‐based smartphone image sensor in a controlled laboratory environment. The CMOS image sensor in the camera possesses inherent sensitivity to UVA, and despite the attenuation due to the lens and neutral density and wavelength‐specific bandpass filters, the measured relative UVA irradiances relative to the incident irradiances range from 0.0065% at 380 nm to 0.0051% at 340 nm. In addition, the sensor demonstrates a predictable response to low‐intensity discrete UVA stimuli that can be modelled using the ratio of recorded digital values to the incident UVA irradiance for a given automatic exposure time, and resulting in measurement errors that are typically less than 5%. Our results support the idea that smartphones can be used for scientific monitoring of UVA radiation. 相似文献