On the Development of Spatial/Temporal Solar UV Irradiation Maps: A Case Study in Pernambuco State (Northeast of Brazil)

This work summarizes recently published information on the solar UV broadband irradiation of Pernambuco, Northeast of Brazil. We describe the spatial and temporal distribution of solar UV radiation and its relationship with climatic and geographical conditions. Statistical experimental correlation between solar total irradiation and UV broadband obtained for 03 locations was generalized by the use of Koppen-Geiger Climatic criterium, which was used for mapping the spatial/temporal distribution of broadband UV. The climatological solar radiations used in the correlations were obtained by modeling through satellite and previously verified with terrestrial data. We present one map with the location of the recording stations where the statistical correlations were measured, one annual and 12 monthly contour maps describing monthly daily solar UV radiation levels throughout the territory of Pernambuco. The solar UV irradiation (“broadband”) annual-average daily value in the State of Pernambuco varied from 226 to 268 Wh/m2. Seasonal variation of solar UV irradiation in the State of Pernambuco follows, in general and as expected, the climate, relief and seasons of the year. The highest value of monthly solar UV irradiation was observed in the central south region of the state, more precisely in Belém do São Francisco, Floresta, Ibimirim and Buíque in the month of December (summer), with 311.8 Wh/m2. The lower value was found in the south Agreste region, in Garanhuns and Caruaru, in the month of June (winter), with 162.2 Wh/m2.

UV-C照射对鲜切豇豆的保鲜效果研究

为探究短波紫外线(UV-C)照射对鲜切豇豆的保鲜效果,在预试验结果的基础上,分别采用0、0.5 kJ/m^(2)的UV-C处理豇豆,然后将其置于4℃条件下贮藏,定期测定相关指标。结果表明:采用0.5 kJ/m^(2)UV-C照射可以维持鲜切豇豆较高的VC、可溶性固形物、可溶性蛋白和叶绿素含量,减少鲜切豇豆丙二醛(MDA)的积累,同时还能保持鲜切豇豆较高的总酚、类黄酮含量,并提高抗氧化酶的活性,包括过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX),一定程度上稳定多酚氧化酶(PPO)的活性。综合来说,0.5 kJ/m^(2)UV-C处理可用于鲜切豇豆的贮藏保鲜。

Red-mud treatment using oxalic acid by UV irradiation assistance

Red-mud is the residue from the Bayer process, in which the iron minerals should be removed before red-mud is used to produce refractory materials. The iron minerals in red-mud were extracted by oxalic acid solution. The content of Fe （calculated in Fe203） in red-mud was reduced from 17.6% to less than 1% after being treated by 1 mol/L oxalic acid solution at 75 ℃ for 2 h. The Fe（Ⅲ） oxalate solution obtained was then irradiated by UV light, resulting in the precipitation of Fe（Ⅱ） oxalate. Under UV photocatalysis, more than 90% of Fe（Ⅲ） oxalate in the extracted solution was transformed into the precipitation of Fe（Ⅱ） oxalate crystallite （fl-FeC2O4·2H2O）. The filtrate from the Fe（Ⅱ） oxalate precipitate filtration could be reused in the next cycle. The mechanism ofUV photocatalysis precipitation was also discussed.

UV-C与柠檬酸处理对采后香蕉贮藏品质的影响

香蕉是富含营养物质且具有重要经济价值的热带水果,也是中国南方四大水果之一。香蕉是一种典型的呼吸跃变型果实,采后乙烯的大量释放使香蕉在贮藏过程中加快成熟和衰老,影响香蕉贮藏保鲜及经济价值。因此有必要研究提高香蕉采后贮藏品质的技术方法,为实践应用提供理论依据。本研究以采后香蕉为材料,分别通过UV-C辐照、柠檬酸浸泡以及二者的复合处理3种方法处理香蕉,在温度为(20±2)℃、湿度为60%~70%的条件下黑暗贮藏12 d,分别于贮藏期的第1、6、9、12天对各组进行随机取样,通过测定硬度、失重率、可滴定酸含量、可溶性固形物含量等生理和品质指标,研究不同处理方法对采后香蕉贮藏品质的影响。结果表明:3.96×10^(-2)KJ/m^(2)UV-C辐照和复合处理(3.96×10^(-2)KJ/m^(2)UV-C辐照+2.0%柠檬酸)对香蕉的保鲜效果明显优于柠檬酸处理,表现为显著抑制果实硬度的下降,延缓失重率的增加,抑制可溶性固形物含量的增加和可滴定酸含量的下降,维持果实糖酸比。在贮藏结束时,与CK相比,UV-C辐照和复合处理的香蕉硬度分别增加9.09%和13.63%,失重率分别减少22.00%和11.43%,糖酸比分别减少40.00%和42.30%。此外,UV-C辐照和复合处理有效抑制了香蕉黄酮类物质、酚类物质和维生素C含量的下降,提高了果实DPPH自由基清除率和抗氧化能力。在贮藏结束时,与CK相比,UV-C辐照和复合处理的维生素C含量分别增加了0.82%和1.27%,总多酚含量分别增加了25.92%和41.65%,总黄酮含量均增加了约30.00%,DPPH自由基清除率分别增加了13.98%和36.59%。综上所述,UV-C辐照和复合处理均可提高采后香蕉贮藏品质,延长其货架期。因此,可以选用该方法作为绿色、安全有效的香蕉采后保鲜技术。

Influences of UV-C Irradiation on Seed Germination and Seedling Growth of Winter Wheat

[Objective] This study aimed to investigate the influences of UV-C irradiation on seed germination and seedling growth of winter wheat. [Method] Winter wheat cul- tivar Liaoda 02 was selected as the experimental material and irradiated with UV-C for 1 h,to compare the dynamic changes of seed germination rate under different treatment time and the changes of gibberellin （GA） content and a-amylase activity during the germination process after UV-C irradiation. Wheat seeds irradiated with UV-C for 1 h were sown, the emergence number, growth speed, fluorescence param- eter, reflectance spectrum, relative conductivity and other related physiological indica- tors of seedlings were determined. [Result] The results showed that the germination rate of dry and wet winter wheat seeds irradiated with UV-C for 1 h was improved, compared with the untreated seeds. After soaked for 6, 8, 10 and 12 h, dry seeds irradiated with UV-C for 1 h showed higher GA content and higher a-amylase activity than the control. In addition, UV-C-irradiated dry seeds also showed faster emergence speed and plant growth speed within the first six days after emergence and greater plant height than the control. The flavonoid content in leaves of the treatment group was also increased compared with the control, while the maximal photochemical effi- ciency （Fv/Fm）, photo-chemical reflectance index （PRI）, chlorophyll and carotenoid content were rarely influenced. In conclusion, UV-C irradiation could improve the ger- mination rate of dry seeds and wet seeds soaked for a certain time, especially for wet seeds soaked for 1 h. Furthermore, UV-C-irradiated seeds showed improved ger- mination speed and plant growth. [Conclusion] This study laid the foundation for ex- ploring the effect mechanism of ultraviolet rays on seed generation.

TOPCon太阳电池的UV辐照衰减特性及抗UV辐照方式研究

对TOPCon太阳电池在不同紫外线(UV)辐照条件下的电性能衰减特性进行了研究,并对提高此类太阳电池抗UV辐照的方式进行了分析。研究结果表明:1)当UV辐照总量达到30 kWh/m2时,在太阳电池背面未盖光伏镀膜玻璃的情况下,TOPCon太阳电池的光电转换效率衰减幅度仅为0.2%左右;相同UV辐照总量下,在太阳电池正面未盖光伏镀膜玻璃情况下,此类太阳电池的光电转换效率衰减幅度却为5.4%~8.3%,表明太阳电池正面和背面的衰减机理可能存在差异,而UV辐照衰减更倾向于对太阳电池正面产生影响,分析原因在于太阳电池正面和背面的钝化方式有所不同,导致正面更容易受到UV辐照衰减的影响。2)在AlOx层厚度保持不变的情况下,当UV辐照总量为50 kWh/m2时,随着Si Nx层折射率从2.00增至2.20,TOPCon太阳电池的光电转换效率衰减幅度从4.03%降至1.22%,这是因为随着SiNx层折射率增加,短路电流、开路电压及填充因子的稳定性得到提升,从而实现了较低的光电转换效率衰减。3)在SiNx层折射率保持2.20不变的情况下,当UV辐照总量为50 kWh/m2时,随着Al Ox层厚度从3.0 nm增至4.8 nm,TOPCon太阳电池的光电转换效率衰减幅度从0.59%降至0.10%,这说明增加AlOx层厚度也可以有效提高太阳电池的抗UV辐照能力。4)提高SiNx层折射率和增加Al Ox层厚度相结合的方式对提高TOPCon太阳电池抗UV辐照能力有较为显著的效果。

Effect of Postharvest UV-C Irradiation on Phenolic Compound Content and Antioxidant Activity of Tomato Fruit During Storage

Mature-green tomato fruit （Solanum lycopersicum cv. Zhenfen 202） were exposed to different UV-C irradiation at 2, 4, 8, and 16 kJ m-2 and then stored under the dark at 14°C and 95% relative humidity （RH） for 35 d. Of these four doses, UV-C irradiation at 4 and 8 kJ m-2 significantly increased total phenolic contents in present tomato fruit by 21.2 and 20.2%, respectively. Furthermore, UV-C irradiation at 4 or 8 kJ m-2 promoted the accumulation of total flavonoids and increased the antioxidant activity. 2 or 16 kJ m-2 UV-C irradiation also enhanced antioxidant activity, but to a lesser extent. Seven phenolic compounds, viz., gallic acid, （＋）-catechin, chlorogenic acid, cafferic acid, syringic acid, p-coumaric acid, and quercetin in tomato fruit were identified and quantified by HPLC. Gallic acid was the major phenolic compound in tomato fruit and significantly correlated with antioxidant activity. 4 or 8 kJ m-2 UV-C irradiation significantly increased the contents of gallic acid, chlorogenic acid, syringic acid, p-coumaric acid, and quercetin. The optimum dose of UV-C irradiation in terms of increased phenolic compound content and enhanced Antioxidant activity was determined to be 4 or 8 kJ m-2.

Photochemical behavior of benzo[a]pyrene on soil surfaces under UV light irradiation

The rates of photodegradation and photocatalysis of benzo [a]pyrene （BaP） on soil surfaces under UV light have been studied. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃ . The rates of BaP photodegradation at different soil particle size followed the order： less than 1 mm〉less than 0.45 mm〉less than 0.25 mm. When the soil depth increased from 1 mm to 4 ram, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 （0.5%, 1%, 2%, and 3% （wt）） or Fe203 （2%, 5%, 7%, and 10% （wt）） did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.

Physicochemical properties of lacquer berries and decolorization of lacquer wax by physical adsorption and UV irradiation

Physicochemical properties of No.1 - No.6 lacquer berries were investigated from different origins. The Japan Showafuku (No.1) was the best cultivar of Rhus succedaneum, the size of the berry of it was near 3 -?4 folds, which was bigger than the Chinese cultivars (No.4 - No.6) of Rhus vernicifera et al. It had more than 5% ~ 10% of lacquer wax in pericard, and contained less than 6% - 8% of lacquer oil in seed. No.1 had lower acid value (A.V) and iodine value (I.V);the key factors for this were cultivar and its growing environment. The principal constituents of lacquer waxes of No.1?- No.6 were triglycerides of fatty acids with total saturated fatty acids (TSFA) of 75% - 82.7%, total unsaturated fatty acids (TUSFA) of 15.1% - 20%, and total dibasic acids (TDBA) of 5%. The CIEL a b system and Hunter whiteness formula were used to evaluate the bleaching effect on lacquer wax by physical adsorption and ultraviolet (UV) irradiation. The optimal conditions of physical decoloration were determined for activated carbon: kieselguhr = 3:2 (g/g) as adsorbent, a ratio of 1:20 (g/mL) for lacquer wax to petroleum ether, bleaching 30 min at 80?C. UV light achieved a good bleaching effect irradiated at 60?C for 60 hrs. UV irradiation definitely changed relative contents of fatty acids, TUSFA and TDBA decreased from 19.617% to 11.022% and 4.379% to 2.017% respectively, while TSFA could be raised from 76.462% to 86.077%, however, the mechanism of UV irradiation was still unclear and should be investigated in the future.

Electrochemical biosensing for dsDNA damage induced by PbSe quantum dots under UV irradiation

An electrochemical sensor for the detection of the natural double-stranded DNA(dsDNA) damage induced by PbSe quantum dots(QDs) under UV irradiation was developed.The biosensing membranes were prepared by successively assembling 3- mercaptopropionic acid,polycationic poly(diallyldimethyl ammonium) and dsDNA on the surface of the gold electrode.Damage of dsDNA was fulfilled by immersing the sensing membrane electrode in PbSe QDs suspension and illuminating it with an UV lamp. Cyclic voltammetry was utilized to detect dsDNA damage with Co(phen)_3^(3+) as the electroactive probe.The UV irradiation,Pb^(2+) ions liberated from the PbSe QDs under the UV irradiation and the reactive oxygen species(ROS) generated in the presence of the PbSe QDs also under the UV irradiation were the three factors of inducing the dsDNA damage.The synergistic effect of the three factors might dramatically enhance the damage of dsDNA.This electrochemical sensor provided a simple method for detecting DNA damage,and may be used for investigating the DNA damage induced by other QDs.

Completely Green Synthesis of Ag Nanoparticles Stabilized by Soy Protein Isolate under UV Irradiation

A completely green pathway for the preparation of Ag nanoparticles was proposed, by using soy protein isolate （SPI） as stabilizer under UV irradiation and H2O as the environmentally benign solvent throughout the preparation. Transmission electronic microscopy （TEM） and zeta potential characterization results indicated that the Ag nanoparticles were stable and well dispersed with an average diameter about 13 nm, and X-ray diffraction （XRD） analysis of SPI/Ag composite nanoparticles confirmed the formation of metallic silver. UV-Vis spectrum showed that the Ag nanoparticles dispersion solution had the maximum absorbance at about 430 nm due to surface plasmon resonance of the Ag nanoparticles. Infrared spectroscopy confirmed that the polypeptide backbone of SPI was not cleaved during the conjugation process and that some active amino groups were oxidized. The SPI/Ag composite nanoparticles have excellent antibacterial activity against two representative bacteria, staphylococcus aureus （Gram positive） and escherichia coli （Gram negative） in the presence of SPI.

Effect of UV Irradiation on PAN Precursor Fibers and Stabilization Process

A low-cost rout for modification the polyacrylontrile（PAN） precursor fibers was developed.The approach involved pretreatment PAN precursor fibers with UV irradiation for various periods of time before the fibers were stabilized.The effect of UV irradiation on the chemical structure,orientation factor,density,crystallite size and morphology of the fibers in the process of stabilization was characterized by use of fourier transform infrared spectroscopy（FTIR）,float-sink procedure,X-ray diffraction（XRD）,scanning electron microscope（SEM）,respectively.The results showed that UV irradiation could increase the density of the fibers in stabilization process.FTIR analysis indicated that the cyclization of nitrile groups was initiated at room temperature by UV irradiation.The transformation of C≡N groups to C=N ones was accelerated in the process of stabilization.The orientation factor of irradiated fibers was also increased.The crystallite size was decreased at first and increased later,and the better irradiation time of UV was 3 min according to the XRD test.SEM analysis indicated that irradiation could decrease the internal and surface defects of the stabilized fibers treated at 300 ℃.

Protective Effect of Gelatin and Gelatin Hydrolysate from Salmon Skin on UV Irradiation-Induced Photoaging of Mice Skin

The objective of this study was to investigate the effect of gelatin(SG) isolated from salmon skin and its hydrolysate(SGH) on photoaging skin, and the mechanism responsible for anti-photoaging. The average molecular weights of SG and SGH were 65 k Da and 873 Da, respectively. The amino acid compositions of SG and SGH were similar. Both of them were abundant in hydrophobic amino acids. Twenty-five peptides were identified from SGH. SG and SGH could improve UV irradiation-induced pathological changes of macroscopical tissue texture and skin morphology. Hydroxyproline content is an indicator of matrix collagen content, SG and SGH could inhibit the decrease of hydroxyproline content in photoaging skin in a dose dependent manner. In addition, SG and SGH could alleviate UV irradiation-induced oxidative damages to skin by increasing the activities of total superoxide dismutase(T-SOD), glutathione peroxidase(GSH-Px) and catalase(CAT), increasing the content of glutathione(GSH) and decreasing the content of malonaldehyde(MDA). Moreover, SG and SGH could enhance immune regulation system by increasing the thymus index. Thus, the anti-photoaging mechanisms of SG and SGH were by inhibiting the depletion of antioxidant defense components, involving in the synthesis of collagen and enhancing the function of immune system. Besides, SGH showed a better result in protecting skin from photoaging than SG.

Solvent effects on gold nanoparticle formation from photochemical reduction of Au(Ⅲ)by UV irradiation

Colloidal gold nanoparticles(AuNPs) have attracted more and more attention in areas of materials science, biotechnology and organic chemistry due to their unique functions as molecular markers and their applications in diagnostic imaging and catalysis. The AuNP synthesis approaches have been well developed; however, the solvent effects have not been systematically studied yet.Here we analyzed and compared solvent effects on AuNP formation using UV irradiation of Au(Ⅲ) without adding any other ligands. By monitoring the surface plasmonresonance absorption of Au(Ⅲ)-containing solutions,results showed that both ketone and alcohol solvents can induce Au(Ⅲ) to form gold nanospheres; on the other hand, solvents like ACN and THF can induce Au(Ⅲ) to form nanostructures with longer dimensions. The possible mechanism was discussed, which could facilitate efficient photochemical synthesis of AuNPs and might apply to other metal NP synthesis.

THE EFFECTS OF MAGNETIC FIELD ON GRAFT COPOLYMERIZATION OF METHYL METHACRYLATE ONTO POLYVINYL ALCOHOL IN THE PRESENCE OF BENZOPHENONE DURING UV IRRADIATION

The effects of magnetic field on the graft ratio and stereoregularity of grafts of PVA-g-MMA in the presence ofbenzophenone during UV irradiation are discussed. By means of IR, it was found that the graft ratio was increased with the increment of magnetic field strength. Furthermore, application of relative weak magnetic field of 0.4 Tesla had been shown to substantially enhance the stereo-regularity of graft copolymer. The maximum stereo-regularity appeared when the graft ratio approached to 85% with the magnetic field of 1.2 Tesla (T). The resistance to moisture and heat resistance of the grafted copolymer in the presence of magnetic field were also improved.

Degradation of Diclofenac in Molecularly Imprinted Polymer Submicron Particles by UV Light Irradiation and HCl Acid Treatment

A new molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP particles were evaluated by equilibrium binding experiments. DFC-MIP aqueous suspension and non-imprinted polymer (NIP) suspension were exposed to monochromatic UV light (253.7 nm) from low-pressure mercury lamps. UV-visible spectrophotometry (especially absorbance at 276 nm) showed that the DFC inside MIP particles degraded completely. After DFC-MIP suspension exposure to UV light the particles were completely regenerated after washing with water at least six times. The regenerated MIP particles rebounded considerable amount of DFC (approximately 88% removal of 44 ppm DFC). The stability of DFC was examined in the presence of various concentrations of hydrochloric acid (0.025 to 125 mM). Experimental results showed that degradation of DFC was efficient, depending on the acid concentration as well as the treatment time. However, there was no re-binding of DFC by the MIP particles after HCl treatment (and DDW washing) when exposed to DFC for 24 hours.

AN INVESTIGATION ON THE INTERACTION MECHANISM OF β-CAROTENE WITH HALOGEN ATOM PRODUCED IN HALOBENZENE BY UV IRRADIATION

ESR measurements using spin trapping technique were carried out for β-carotene-halobenzene system under UV light irradiation.The ESR spectra observed in the presence and in the absence of β-carotene are markedly different.The possible scheme of β-carotene interacting with halogen atom was proposed.

Evaluation of UV Optical Fibers Behavior under Neutron Irradiation

Degradation of UV transmitting optical fibers under nuclear reactor neutron exposure is reported. Four type of optical fibers (solarization resistant, H2-loaded;UV transmission standard OH;UV enhanced transmission, high OH, H2-loaded;high OH, deep UV enhanced) were exposed to neutron fluences up to 4 x 1017 n/cm2. The optical transmission was measured off-line over the 200 nm – 900 nm spectral range and the build-up of color centers was monitored.

Photochemical Reactions of Microcystin-LR Following Irradiation with UV Light

Photochemical reactions of microcystin-LR, a toxic compound produced by some blue green algae, were investigated. Ultraviolet absorption of microcystin-LR was assessed. Time-dependent density functional theory (TDDFT) calculations indicated that absorption peak at 238 nm was mainly due to excitation of electrons from the linear chain structure Adda of microcystin-LR. Irradiation of microcystin-LR with UV light resulted in the reduction of the 238 nm absorption peak and the appearance of a new peak at 300 nm. Density functional theory (DFT) and TDDFT calculations with a model molecule suggested that this 300 nm peak was due to tricyclo-Adda microcystin-LR, an intermediate in photochemical reactions of microcystin-LR. Analysis of the rate of this photochemical reaction showed that it was a first order reaction.

Chemical Dosimetry during Alpha Irradiation: A Specific System for UV-Vis <i>in Situ</i>Measurement

This paper is devoted to the study of the potentiality of the Fricke dosimeter for the characterization of the highly energetic (62.1 MeV) α particles beams generated by a new cyclotron facility, namely ARRONAX started in 2009. Such for this high energetic α beam, in situ dosimetry is performed in order to avoid radiation safety inconvenience and to earn run time of irradiation. Therefore, an in situ Fricke dosimetry protocol is developed and its reliability is checked by comparison with other experiments carried out by using the traditional method (ex situ Fricke dosimetry) within another cyclotron facility (CEMHTI) and by comparison with literature data. To author’s knowledge, it is the first time that Fricke dosimetry is performed during the α irradiation experiment. The results of these in situ dosimetry experiments show that the value of ferric ions radiolytic yield (G(Fe3+) = (11.7 ± 1.2) 10–7 mol?J–1) extrapolated from literature data can be used for this higher energy of α particles (Eα = 62.1 MeV).