Effect of Ultraviolet Aging on the Bonding and Tensile Properties of Polymer-Cement Composite

In this paper,the specimens of polymer-cement composites after 1 d,7 d,15 d,and 30 d aging without aging and UV aging are subjected to fixed extension test and tensile test.By observing the mode of the composite in the fixed-elongation test,and measuring the elastic recovery rate,tensile strength,elongation at break,peak tensile strain,tensile toughness and pre-peak tensile toughness of the composite,the effects of UV aging on the bonding and the tensile properties of the composite were studied.And combining with scanning electron microscopy experiments,the micro-mechanism of the effect of ultraviolet aging on the properties of composite was analyzed.The results showed that the composite had a good bonding property,and no damage was observed after UV aging for 30 days.The UV aging increased the elastic recovery rate and peak tensile within a certain range.The elastic recovery rate and peak tensile strain of the composite increased by 6.60%and 23.55%respectively after UV aging for 15 days.Therefore,the UV aging could enhance the tensile property and the tensile energy consumption performance of the composite.The tensile strength of the composite increased by 65.36%after UV aging for 30 days.The tensile toughness and pre-peak tensile toughness of the composite were increased by 43.29%and 101.83%respectively after UV aging for 15 days.The elongation at break of composite decreased continuously after UV aging due to the photo-oxygen reaction,as well as secondary hydration reaction and cross-linking curing reaction of cement.

Evaluation of the in vitro antimicrobial properties of ultraviolet A/riboflavin mediated crosslinking on Candida albicans and Fusarium solani

AIMTo evaluate the antimicrobial properties of ultraviolet A (UVA) (365 nm)/riboflavin against Candida albicans and Fusarium solani.

Promising Ultraviolet Absorbers——Novel Guanine Analogs Having Significantly Improved Ultraviolet Absorption Capacity and Dissipating the Energy of Absorbed Photons by Nonradiative Decay Mechanism

Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight guanine analogs[N-2-（2＇-nitrobenzoyl）-guanine, N-2-（3＇-nitrohenzoyl）-guanine, N-2-（4＇-nitrobenzoyl）-guanine, N-2-（2＇-hydroxybenzoyl）-guanine, N-2-（4＇-methoxylbenzoyl）-guanine, N-2-（4＇-chloricbenzoyl）-guanine, N-2-（4＇- me- thylicbenzoyl）-guanine and N-2-（3＇,5＇-dinitrobenzoyl）-guanine] with different substituted benzoyls, except N-2-（4＇-chloricbenzoyl）-guanine, were newly synthesized. In contrast with guanine, they exhibit wider ultraviolet absorbent range, higher molar extinction coefficient and lower fluorescence intensity.

Ultraviolet and mid-infrared continuum generation by cross-phase modulation between red-shifted solitons and blue-shifted dispersive waves in a photonic crystal fiber

Using a photonic crystal fiber with a zero dispersion wavelength of the fundamelItal mode at 780 nm designed and fabricated in our lab, the ultraviolet and mid-infrared continua are generated by cross-phase modulation between red-shift solitons and blue-shift dispersive waves. The dependences of continuum on the pump power and wavelength are investigated. With the pump working at 820 nm, when the pump power increases froul 300 to 500 mW, the bandwidths of ultraviolet and mid-infrared continua change from 80 to 140 nm and 100 to 200 nm, respectively. The wavelength of ultraviolet continuum is below 246 nm, and the wavelength of mid-infrared continuum exceeds 2500 nm. Moreover, the influences of pump power on wavelength and conversion efficiency of different parts of continua are also demonstrated.

STUDIES ON THE EFFECT OF DISSOLVED IONS ON SCO DEPRESSING PROPERTY USING ULTRAVIOLET ABSORPTION SPECTRA

SCO is a selective dolomite deperessant in the flotation system of collophane and dolomite. However,experi-ments confirmed that reverse phenomenon would occur for some phosphatic mines. In order to explain the SCO depress-ing mechanism i this paper describes studying results on the ef-fect of dissolved ions on SCO depressing property using ul-traviolet absorption spectra. It is found that the effect of dis-solved ions, especially Mg2+ ?on the SCO adsorption property is strong. When Mg2+ concentration is low,dolomite adsorbs SCO and is depressed. When Mgz+ concentration is more than 90g/t in pulp.SCO adsorption capacity on colophane is obvi-ously greater than that on dolomite,which results in the de-pression of collophane. The adsorption results are consistent with flotation results.

Higher order harmonics suppression in extreme ultraviolet and soft x-ray

The extreme ultraviolet and soft x-ray sources are widely used in various domains. Suppressing higher order harmonics and improving spectral purity are significant. This paper describes a novel method of higher order harmonics suppression with single order diffraction gratings in extreme ultraviolet and soft x-ray. The principle of harmonic suppression with single order diffraction grating is described, and an extreme ultraviolet and soft x-ray non-harmonics grating monochromator is designed based on the single order diffraction grating. The performance is simulated by an optical design software. The emergent beams of a monochromator with different gratings are measured by a transmission grating spectrometer. The results show that the single order diffraction grating can suppress higher order harmonics effectively, and it is expected to be widely used in synchrotron radiation, diagnostics of laser induced plasma, and astrophysics.

Effect of a Single Threading Dislocation on Electrical and Single Photon Detection Characteristics of 4H-SiC Ultraviolet Avalanche Photodiodes

We fabricated 4H-SiC ultraviolet avalanche photodiode(APD)arrays and systematically investigated the effect of threading dislocations on electrical and single photon detection characteristics of 4H-SiC APDs.Based on a statistical correlation study of individual device performance and structural defect mapping revealed by molten KOH etching,it is determined with high confidence level that even a single threading dislocation within APD active region would lead to apparent device performance degradation,including increase of dark current near breakdown voltage,premature breakdown and reduction of single photon detection efficiency at fixed dark count rate.

Laboratory research on rheological behavior and characterization of ultraviolet aged asphalt

The influence of aging on the evolution of structural,morphological and rheological properties of neat asphalt was investigated by Fourier transform infrared(FTIR),atomic force microscopy(AFM) and dynamic shear rheometer(DSR),respectively.Asphalt was suffered under 20 W/m2 of UV radiant intensity and under the condition of aging time(0,48,96 and 144 h) with film thickness of 100 μm and film thickness of 50,100,200 and 500 μm after aging for 120 h,respectively,at certain UV radiant intensity 20 W/m2.Rheological results tested by DSR exhibit higher the complex shear(stiffness) modulus(G*) and lower phase angle(δ),compared to the virgin at the same test condition.The compositions analysis of asphalt before and after aging show an increase of carbonyl and sulfoxides,while a decrease of aromatic functional groups.With the increase of the component of asphaltene,obvious agglomerates of asphalten appear in neat asphalt surfaces after aging.

Preparation and Anti-ultraviolet Aging Performance of Organic Layered Double Hydroxides/Bitumen Composites

Layered double hydroxides(LDHs) with the physical property of high ultraviolet(UV)reflectance were used to enhance the anti-UV aging performance of bitumen. In view of the poor compatibility of LDHs with bitumen, three organic anions, namely, sodium dodecyl benzenesulfonate(SDBS), sodium dodecyl sulfate(SDS) and sodium dodecyl sulfonate(SDSO), were used as modifiers to prepare organic LDHs(OCLDHs) through regeneration process, and the crystal structure, chemical composition, morphological feature and UV shielding capability of synthesized OCLDHs were analyzed. Then the OCLDHs were added into bitumen to evaluate the storage stability and anti-UV aging property of OCLDHs/bitumen composites.The results show that the organic anions are inserted into the interlayers of LDHs, the intercalation expands the interlayer distance of LDHs, makes the particle shapes become more irregular and complicated, and enhances the absorption ability within the range from 200 to 300 nm while has little influence on the UV reflection ability.Result of high temperature storage stability indicates the organic modification ameliorates the compatibility of LDHs with bitumen. Compared with LDHs, OCLDHs decrease the deteriorations of bitumen’s properties during UV exposure test, exhibiting better effect in enhancing anti-UV aging performance of bitumen. Furthermore,among the three OCLDHs, LDHs intercalated by SDBS exhibit the most effective improvement due to the best compatibility with bitumen and comparatively good UV shielding effect.

Ground-based Observations of Ultraviolet and Total Solar Radiation in Shenyang,Northeast China

Objective This work explores the diurnal variation of Solar ultraviolet radiation （UVR） and total solar radiation （TSR） in northeast China,using daily observations of UVR and TSR in Shenyang.Methods UVR and TSR measurements were carried out from March 1st,2006 to December 31st,2009 in Shenyang,Liaoning province,China （41°51＇ N,123°27＇ E）.Results Both TSR and UVR showed seasonal variation,reaching the highest levels in summer and the lowest in winter.They showed the greatest fluctuation in summer and autumn.The irradiance of TSR and UVR on clear days around the equinoxes and solstices increased substantially compared with the mean seasonal irradiance,especially in autumn.The whole day accumulated dose of UVR in winter was far less than that during the middle part of a summer day （i.e.between 10：00 and 14：00）.It was also less than the accumulated summer dose of morning and afternoon （i.e.between 8：00 and 10：00 and 14：00 and 16：00）.Conclusion The instant irradiance and daily accumulated amount of UVR are low in Shenyang,especially in autumn and winter.Thus concern about the health effects arising because shortage of UVR in northeast China is warranted.

Comprehensive Evaluation on Impacts of Diseases on Quality of Paris polyphylla var. chinensis Based on Ultraviolet and Infrared Spectra

[Objectives] The research aimed to evaluate impacts of diseases on quality of Paris polyphylla var. chinensis. [Methods]Ultraviolet spectrophotometry was used to determine and contrast content of total saponins in root,stem and leaf from healthy and diseased plants. Infrared characteristic absorption peaks of healthy and diseased plants were found by infrared fingerprint method for comparative analysis.[Results]Total saponins content in root sample J4 of healthy plant reached 4. 89% and was the highest,while it was 0. 13% in stem sample J11 of healthy plant and was the lowest. Total saponins content in root sample B1 of diseased plant was 1. 68% and was the highest,while it was 0. 1% in stem sample B7 of diseased plant and was the lowest. In healthy and diseased plants,total saponins content in root was significantly higher than that in stem and leaf. Content of total saponins in root from healthy plant was significantly higher than that from diseased plant,and there was little difference in stem and leaf of healthy and diseased plants. Root sample Jg of healthy plant had obvious C-O characteristic vibration of polysaccharides and glycosides and absorption peak of O-H bending vibration in steroidal saponin near 1 160. 02 cm-1,while diseased plant had no obvious absorption peak. Near 861. 97 and 768. 07 cm-1,root sample Jg of healthy plant had significant C-C stretching vibration in sugar ring and characteristic absorption peak of characteristic vibration of steroidal saponin,while root sample Bg of diseased plant had no obvious characteristic peak. [Conclusions] Diseases significantly affected composition and content of total saponins and steroidal saponins from P. polyphylla var. chinensis,further affecting quality of P. polyphylla var. chinensis.

Preparation and Characterization of Lignosulfonate Intercalated Layered Double Hydroxides and Their Application in Improving Ultraviolet Aging Resistance for Bitumen

In order to develop economically anti-ultraviolet(UV) aging additives to bitumen and extend the comprehensive utilization of lignin materials, lignosulfonate(LS) was selected to intercalate into layered double hydroxides(LDHs), then the LS intercalated LDHs(LS-LDHs) were applied to improve UV aging resistance of bitumen. With the characterization of X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, chemical analysis and scanning electron microscopy(SEM), LS was successfully intercalated into the galleries of LDHs. The ultraviolet and visible(UV-vis) absorbance curves showed LS-LDHs had excellent UV absorptive ability from 200 to 400 nm. Thermogravimetry and differential scanning calorimetry(TG-DSC) indicated LS-LDHs could have a good thermal stability during the processing of bitumen. Compared with the LDHs, the LS-LDHs exhibited better performance in UV aging resistance of bitumen.

Mutagenesis of T richoderma V iride by Ultraviolet and Plasma

Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet （UV） and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.

Three-Photon Resonant Third Harmonic Generation of H2 in Vacuum Ultraviolet and Extreme Ultraviolet Regions

Tunable coherent vacuum ultraviolet and extreme ultraviolet radiation have been produced in H2 by three-photon resonant third harmonic generation via B1 Σ_(u)^(+)(v’) ← X^(1) Σ_(g)^(+) (v = 0 ) and C^(1) IIu(v’) ← X^(1) Σ_(g)^(+) ( v = 0 ) transitions. Highly resolved third harmonic spectrum exhibits some distinct characteristics. Phase-matching effect of the nonlinear optical process is also discussed.

Feasibility of Extreme Ultraviolet Active Optical Clock

We propose an experimental scheme of vacuum ultraviolet(VUV)and extreme ultraviolet(XUV)optical frequency standards with noble gas atoms.Considering metastable state 3𝑃2 noble atoms pumped by a conventional discharging method,the atomic beam is collimated with transverse laser cooling at the metastable state and enters into the laser cavity in the proposed setup.Due to stimulated emission from the metasable state to the ground state inside the laser cavity consisting of VUV reflection coating mirrors,our calculations show that with enough population inversion to compensate for the cavity loss,an active optical frequency standard at VUV and XUV is feasible.

Lentinula edodes extract inhibits matrix metalloproteinase expression and increases typeⅠprocollagen expression via the p38 MAPK/c-Fos signaling pathway in ultraviolet A and B-irradiated HaCaT keratinocytes

Objective:To determine the effect of Lentinula edodes extract on ultraviolet(UV)A and UVB-induced changes in matrix metalloproteinase(MMP)and type I procollagen expression using human immortalized HaCaT keratinocytes.Methods:Lentinula edodes ethanol extract(LEE)was obtained by extraction with 80%ethanol for 4 h at 80℃.Effect of LEE on UVinduced alteration on the expression and production of MMPs and type I procollagen in keratinocytes was investigated using ELISA,RT-PCR,and Western blotting assay.To determine the underlying mechanism of LEE-mediated effects,mitogen-activated protein kinase(MAPK)and activator protein 1 signaling pathways were analysed by Western blotting assay.Results:LEE significantly inhibited the expression of MMP-1 and MMP-9 and increased the expression of type I procollagen in UVA and UVB-irradiated HaCaT keratinocytes.The phosphorylation levels of p38 were significantly inhibited by LEE whereas it did not affect c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation.Suppression of p38 phosphorylation was also accompanied by downregulation of UVA and UVB-induced increase in c-Fos.Conclusions:LEE effectively inhibits the expression of MMP-1 and MMP-9 and increases type I procollagen production through the p38 MAPK/c-Fos signaling pathway in UVA and UVB-irradiated HaCaT keratinocytes.This findings suggest that Lentinula edodes may be developed as a cosmetic material to suppress UV exposuremediated skin aging.

Deep-ultraviolet and visible dual-band photodetectors by integrating Chlorin e6 with Ga_(2)O_(3)

Gallium oxide(Ga_(2)O_(3))is a promising material for deep-ultraviolet(DUV)detection.In this work,Chlorin e6(Ce6)has been integrated with Ga_(2)O_(3)to achieve a DUV and visible dual-band photodetector,which can achieve multiple target information and improve the recognition rate.The photodetector shows two separate response bands at 268 nm and 456 nm.The DUV response band has a responsivity of 9.63 A/W with a full width at half maximum(FWHM)of 54.5 nm;the visible response band has a responsivity of 1.17 A/W with an FWHM of 45.3 nm.This work may provide a simple way to design and fabricate photodetectors with dual-band response.

Ultraviolet and visible upconversion dynamics in Er^3＋：YAlO3 under ^2H11/2 excitation

The luminescence of Er^3＋：YAlO3 in ultraviolet visible and infrared ranges under the 518 nm excitation of the multiples ^2H11/2 have been investigated. Ultraviolet （275 nm and 318 nm）, violet （405 nm and 413 nm） and blue （474 nm） upconversion and infrared downconversion luminescence has been observed. By means of measuring the fluorescence decay curves and using the theory of rate equations, the luminescence kinetics was studied in detail and the processes of energy transfer upconversion （ETU） and excitation state absorption （ESA） were proposed to explain the upconversion phenomena.

Study of blood fat concentration based on serum ultraviolet absorption spectra and neural network

Blood plays an important role in the clinical di-agnosis and treatment, the analysis of blood will be of very important practical significance. The experiment shows that the absorption spectra of blood are of serious noise in the wave band of 200 to 300 nm, which hides the useful spectral characteristics. The effective separation of the noise was achieved by db4 wavelet transform, and the signals of reconstruction have been obviously improved in the noise serious wave band, reflecting some useful information. The absorption peaks of different samples are displaced to some degrees. The correlation between absorbance at 278nm and blood fat concentration is no significant and random. Based on the evident correlation between serum absorption spectrum and blood fat con-centration in the wave band of 265 to 282nm, a neural network model was built to forecast the blood fat concentration, bringing a relatively good prediction. This provides a new spectral test method of blood fat concentration.

Effect of Ultraviolet Radiation on Hsp70 Protein Expression in HaCaT Cells

Ultraviolet radiation by its wavelength is divided into: UVA, UVB and UVC. Only UVA and UVB manage to penetrate the ozone layer, but due to anthropological activities, all of them are capable of interacting with humans to a greater or lesser extent, and can generate adverse effects such as cellular stress when interacting with intra-and extracellular biomolecules. The skin is the first organ in contact with UV radiation, and the stress it generates can be analyzed by the expression of a bioindicator of cellular damage such as Hsp70. Therefore, the objective of the project was: to determine the effect of UVA, UVB and UVC radiation on HaCaT epithelial cells, by analyzing the expression of Hsp70. Materials and methods: HaCaT cells were cultured in vitro, which were irradiated with UVA, UVB and UVC light at different doses, to subsequently determine the degree of Hsp70 expression by Immunodetection by PAGE-SDS and Western Blot. Results: Basal expression of Hsp70 was observed in no irradiated HaCaT cells. When HaCaT cells were irradiated with UVA, UVB, UVC, an increase in this Hsp70 protein was observed. With UVA, a higher degree of expression was observed at a time of 30 minutes of irradiation. With UVB the highest expression shifted to a time of 20 minutes. With UVC, overexpression was observed after 10 minutes. Conclusion: UV radiation generates cellular stress on HaCaT cells, evaluated by the stress bioindicator Hsp70. According to the wavelength of UV radiation, those that have a shorter wavelength have a greater potential for cellular damage, such as UVC.