ultraviolet

摘要： Aircraft paint must not just look good. It must be able to stand up to the stressors of high ultraviolet levels during flight, along with frequent and significant temperature and humidity changes, which can promote corrosion.

摘要： Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global investment in the manufacturing infrastructure associated with In Ga N material that has become the second most important semiconductor material after Si in the late 2010s[1,2].

摘要： Hideki Hirayama received his Ph.D.from Tokyo Institute of Technology in 1994.He joined RIKEN from 1994 and he was appointed Chief Scientist and Director of Quantum Optodevice Laboratory since 2012.His research interests include crystal growth of wide bandgap AlN-based nitride semiconductors and development of deep-UV emitters.Ultraviolet(UV)radiation,which is an important component of solar radiation,can be divided into three bands,comprising the UV-A band(320-400 nm),the UV-B band(280-320 nm),and the UV-C band(100-280 nm).UV radiation affects not only the survival and continuing development of humankind,but also has a variety of important applications,including high-resolution light sources,phototherapy,disinfection,sterilization,deodorization,organic decomposition,photo catalysis,gas sensing,optical dialysis dosage monitoring,and the identification of hazardous biological agents[1].

摘要： Progress in the design and fabrication of ultraviolet and deep-ultraviolet groupⅢ–nitride optoelectronic devices,based on aluminum gallium nitride and boron nitride and their alloys,and the heterogeneous integration with two-dimensional and oxide-based materials is reviewed.We emphasize wide-bandgap nitride compound semiconductors(i.e.,(B,Al,Ga)N)as the deep-ultraviolet materials of interest,and two-dimensional materials,namely graphene,two-dimensional boron nitride,and two-dimensional transition metal dichalcogenides,along with gallium oxide,as the hybrid integrated materials.We examine their crystallographic properties and elaborate on the challenges that hinder the realization of efficient and reliable ultraviolet and deep-ultraviolet devices.In this article we provide an overview of aluminum nitride,sapphire,and gallium oxide as platforms for deep-ultraviolet optoelectronic devices,in which we criticize the status of sapphire as a platform for efficient deep-ultraviolet devices and detail advancements in device growth and fabrication on aluminum nitride and gallium oxide substrates.A critical review of the current status of deep-ultraviolet light emission and detection materials and devices is provided.

摘要： In recent years,because of their small size,high efficiency and environment-friendly advantages,Ⅲ-nitride based ultraviolet(UV)light-emitting diodes(LEDs)have been widely used in many areas to substitute for mercury lamps,such as in 3D printing,curing and sterilization.Ⅲ-nitride alloys cover the whole UV spectrum which is comprised of UV-A(320–400 nm),UV-B(280–320 nm)and UV-C(200–280 nm)by controlling Al/Ga/In content.In addition,Ⅲ-nitride based UV laser diodes(LDs)also have some potential applications in the case of high-power-density,narrow-spectrum,good-directional lighting.However,Ⅲ-nitride based UV laser diodes still have many challenges such as poor crystal quality and low hole concentration in p-type AlGaN.

摘要： AIM To assess the role of narrow band ultraviolet B(UVB) as a treatment option in peritoneal dialysis patients with refractory uremic pruritus.METHODS In this retrospective study, 29 adult patients with end stage renal failure on peritoneal dialysis, and who had refractory uremic pruritus, were given narrow band UVB radiation as an add-on therapy to standard care for a duration of 12 wk. The response to the pruritus was assessed both weekly and at the end of the study period using a visual analogue score(VAS).RESULTS The average VAS score at the end of the study was 3.14 ± 1.59, which was significant compared to the baseline value of 7.75 ± 1.02(P < 0.05). Improvements in symptoms were noted in 19 out of 21(90.4%) patients. However, relapse occurred in six out of the 19 patients who responded. The dropout rate was high during the study period(33.3%).CONCLUSION Narrow band UVB is effective as an add-on therapy in peritoneal dialysis patients with refractory uremic pruritus. However, the present regime is cumbersome and patient compliance is poor.

摘要： We produced Wood-Polymer Composites (WPCs) with phenolic resin (PR) filled with saw dust (SD) and rice husks (RH) in a PR:fillerratio of 60:40 wt.%. RH and SD were grinded and sieved into particles μm. The aim of this research work was to evaluate sawdust and rice husks as fillers for sustainable phenolic resin based WPCs. Therefore, we investigated the thermal stability of PR/RH and PR/SD WPCs then we studied and compared the tensile, flexural properties of PR/SD and PR/RH WPCs samples, as well as their dimensional stability after water absorption test. Furthermore, through ultraviolet light exposure, we evaluated the effects of photo-oxidation on the water stability and mechanical properties of PR/RH and PR/SD WPCs samples compared to unexposed ones. PR filled with SD presented better mechanical properties compared to PR/RH WPCs samples. However, PR/RH WPCs showed good mechanical properties, and better thermal resistance and better water repulsion capabilities compared to PR/SD WPCs samples. Although, long time UV exposure ended up lowering considerably the mechanical properties and water resistance of PR/SD and PR/RH WPCs, both RH and SD offer great added value as fillers for PR based WPCs;SD having better interactions with PR matrix compared to RH.

摘要： The present study showed that avian influenza virus (AIV) occurred in the regions with rice and wheat productions under low ultraviolet (UV) radiation while there were negligible AIV outbreaks in the regions with a high rate of skin cancer due to extensive UV radiation. It is therefore proposed that having artificial UV radiation with poultry farmhouses is a simple solution to suppress AIV outbreaks. AIV outbreaks can be predicted a few months in advance by remote sensing satellite parameters such as Cosmos (minimum sunspot number, 10.7 cm solar flux, high UV radiation), Poles (CO2, O3 hole deterioration, hydroxyl layer temperature, ice-melting, chlorophyll or algae, krill, penguin, guillemot), and Continents (migratory birds, desert dust, low UV radiation, waters, fish, rice and wheat, climate). Since there was an abrupt 2% rise of global CO2 emissions in 2017, while the minimum sunspot number is simultaneously reached at the end of 2018, there can be an extensive UV radiation for mutant AIV in the Poles to have the highest degree of damage by AIV in regions such as U.S., East Asia, China, South Korea, Japan, west Africa, and Europe from November of 2018 till April of 2019.

摘要： Reactive oxygen species(ROS)level is elevated when ionizing radiation interacts with water molecules,which produces additional ROS via radiolysis of water molecules.To prevent excessive generation of ROS during radiation exposure,addition of antioxidants has been shown to protect cells from the harmful effects of ionizing radiation both in vitro and in vivo.Several enzymes contribute to the ROS generation in vivo,including NADPH oxidase.Environmental stress factors such as nutrient stress,heavy metals,and ultraviolet radiation could activate NADPH oxidase to produce ROS.