60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin ...60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin film with the largest UV cut-off wavelength. The sample films with CeO2：TiO2=60：40 were heated at 773 K, 873 K, 973 K for 30 min. These films are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and X-ray photoelectron spectroscopy and spectrometer （XPS）. XRD analysis proves that the addition of TiO2 to CeO2 changed the crystalline state of CeO2. But the UV absorption effect of CeO2-TiO2 films with CeO2 crystallite phase is inferior to that of the amorphous phase CeO2-TiO2 films. XPS analysis also indicates that the amorphous phase CeO2-TiO2 films have the most Ce3＋ content in these films. Amorphous phase and crystalline phase of the CeO2-TiO2 films have different effects on UV absorption of the thin films.展开更多
The nanometer yellow iron oxide was prepared by oxidizing Fe（OH）2 with air, which was verified with XRD and TEM. The result shows that nanometer yellow iron oxide is spindle-shaped and well-distributed with a long a...The nanometer yellow iron oxide was prepared by oxidizing Fe（OH）2 with air, which was verified with XRD and TEM. The result shows that nanometer yellow iron oxide is spindle-shaped and well-distributed with a long axis of 150-200 nm and short axis of 40-50 nm. Ultraviolet （UV） transmittance of the iron oxide shows the great effect of concentration on both transparency and UV ab- sorption, and it has been proven that iron oxide with a concentration of 0.025wt% is preferred. The spectrum of XRD indicates that it is goethite. When the yellow iron is dispersed in sol, given that the wavelength of UV is less than 300 nm, its UV absorption capacity is superior to those of ZnO and TiO2. The absorption capacity of the yellow iron is less than TiO2 and more than ZnO as the wavelength of UV is 300-400 nm.展开更多
Objective： The aim of our study was to discovery the different cell cycle arrest effect after different densities HeLa cells treated with Trichostatin A （TSA）. In addition, this study would find some important rela...Objective： The aim of our study was to discovery the different cell cycle arrest effect after different densities HeLa cells treated with Trichostatin A （TSA）. In addition, this study would find some important relationship between cycle arrest effect and UV absorption spectrum of cell. Methods： 0.2 IJM TSA was applied to act on HeLa cells of different density. Then, the cycle arrest effect and UV absorption spectrum of cells were investigated, which provide support to analyze the effect of TSA on cancer cells. Results： Cell cycle arrest effect in G0/G1 of the lower density cells was more obvious than that in other groups. The other discovery in this work was that the cellular UV absorption value was higher when the density of cultured cell was lower. Conclusion： This experiment would guide the clinical study on early or late stage cancer patients in the future. On the other hand, this work indicates when cells were arrested in G0/G1 phase, the cellular absorption value increased at the same time, so UV absorption spectrum could characterize the change of cell cycle.展开更多
In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plas...In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge（DBD）for applications in plasma medicine.The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen.One of the emitted wavelengths is an important resonance wavelength of nitric oxide（λ = 226.2 nm）.By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength,and measuring the change in intensity by the absorbing plasma,the concentration of nitric oxide inside the plasma can be calculated.The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm,so that a distance of about 10 cm to the respiratory tract is enough to conform to the VDI Guideline 2310.展开更多
Twenty five samples of 4,4'-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, aceto...Twenty five samples of 4,4'-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, acetonitrile and ethanol, in which 242 experimental data were recorded. The effects of substituents and solvents on the energy of their UV absorption max wavelengths were discussed. The research results showed: the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was mainly affected by their intramolecular structure (substituent effect) in a given solvent, that is, the energy is dominated by both of excited-state substituent parameter o-~c and polar substituent constant crp. While their energy was dominated by the substituent effect and solvent effect in different kinds of solvents. An equation quantifying the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was developed. In addition, it is found that the n-octanol/water partition coefficient (logP) is more effective than the solvatochromic dye (ET(30)) in scaling the solvent effect. The equation employed the parameter logP has a better correlation and more specific physical meaning. Further, the energies of UV absorption max wavelengths of some reported compounds were predicted by the obtained equation, which are in agreement with their experimental values.展开更多
Due to the complexity of the structure within melanin and synthetic polymers(i.e.,polydopamine,PDA),it is a challenge to regulate the ultraviolet(UV)absorption.In nature,melanocytes can biosynthesize more pheomelanins...Due to the complexity of the structure within melanin and synthetic polymers(i.e.,polydopamine,PDA),it is a challenge to regulate the ultraviolet(UV)absorption.In nature,melanocytes can biosynthesize more pheomelanins than eumelanins via protein and gene overexpression for photoprotection when the UV irradiation is enhanced.During this biosynthetic pathway,L-cystine,transported by xCT gene,can be involved to form a new monomer structure incorporating a benzothiazole group,finally resulting in the formation of UV absorption-enhanced pheomelanin.Inspired by this,we have proposed a facile strategy to regulate the UV absorption of PDA by introducing the benzimidazole(BI)unit through the thiol-Michael addition reaction during the polymerization process.It was further found that the introduction of BI units not only significantly increased the content of chromophores and auxochromes,but also effectively restricted the red-shift of the absorption spectrum via interrupting the conjugated microstructure within PDA,both of which contribute to UV absorption enhancement.These UV absorption-enhanced PDA nanoparticles could be used to fabricate bio-inspired sunscreens for efficient sun protection.This work will provide a facile strategy to regulate UV absorption of melanin-like materials and open new horizons for the design and construction of bioinspired sunscreens.展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible spectrum.However,their intrinsically weak light absorption and t...Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible spectrum.However,their intrinsically weak light absorption and the low photoluminescence quantum yield(PLQY)restrict their performance and potential use,especially in ultraviolet(UV)wavelength light ranges.Quantum dots(QD)derived from 2D materials(2D/QD)provide efficient light absorption and emission of which energy can be tuned for desirable light wavelength.In this study,we greatly enhanced the photon absorption and PLQY of monolayer(1L)tungsten disulfide(WS_(2))in the UV range via hybridization with 2D/QD,particularly titanium nitride MXene QD(Ti_(2)N MQD)and graphitic carbon nitride QD(GCNQD).With the hybridization of MQD or GCNQD,1LWS_(2)showed a maximum PL enhancement by 15 times with 300 nm wavelength excitation,while no noticeable enhancement was observed when the excitation photon energy was less than the bandgap of the QD,indicating that UV absorption by the QD played a crucial role in enhancing the light emission of 1L-WS_(2)in our 0D/2D hybrid system.Our findings present a convenient method for enhancing the photo-response of 1L-WS_(2)to UV light and offer exciting possibilities for harvesting UV energy using 1L-TMD.展开更多
Background:Long-term exposure to sunlight can lead to inflammatory responses,skin photoaging and cancers.Plant extracts can serve as effective biological UV(ultraviolet)filters for their UV absorption capacity.Red ric...Background:Long-term exposure to sunlight can lead to inflammatory responses,skin photoaging and cancers.Plant extracts can serve as effective biological UV(ultraviolet)filters for their UV absorption capacity.Red rice extract is rich in phenolic acids,flavonoids,anthocyanins and procyanins has the potential as a biological UV filter.Aims:This study aims to evaluate the potential of red rice extract as a biological UV filter.Forthurmore,exploring the ability of red rice extract to enhance SPF performance and serve as a potential substitute for chemical UV filters.Methods:Using UV absorption spectroscopy,the UV absorption performance of red rice extract was compared with that of three known UV filters.Additionally,using the Folin-Ciocalteu reagent to test the total phenolic acids content of red rice extract and the antioxidant capacity of red rice extract was verified through a 2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical clearance assay,confirming its potential as a biological UV filter.Subsequently,the photoprotective enhancement effects of red rice extract in sunscreen formulations were explored by testing the SPF value with UV2000S.Results:Experiments conducted by adding different concentrations of red rice extract to sunscreen formulations demonstrated that its photoprotective enhancement effects were positively correlated with its concentration.The addition of 1%red rice extract to both oil-in-water(O/W)and water-in-oil(W/O)sunscreen formulations demonstrated good photoprotective enhancement effects,with SPF values increasing by over 10%.Further experiments showed that 1%,3%,and 5%red rice extract could replace approximately 12.82%,19.05%,and 26.09%of traditional UV filters in sunscreen formulations,achieving similar SPF values.Conclusions:These findings suggest that red rice extract is a promising biological UV filter,capable of enhancing SPF values and serving as a viable alternative for traditional UV filters.Red rice extract can be used in sunscreen products and provide photoprotection benefit.展开更多
A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coeffici...A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coefficient was 0.9805, and the standard deviation was only 672.27 cm^-1. The results imply that the excited-state substituent constant can be used productively for research on UV energy of 1,4-disubstituted benzenes. The present method provides a new avenue to study the UV absorption spectra of aromatic systems with the excited-state substituent constant, and it is helpful to understand the effect of substituent electrostatic effects on the chemical and physical properties of conjugated compounds with multiple substituents in excited state.展开更多
Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when...Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when heat treatment temperature is 450℃,and at 800℃,TiO_2 particle size is of below 100 nm and rutile structure is presented.In the range of 360 nm～400 nm the transmittance of TiO_2 sol increases with the increasing of the concentration of Ti(OC_4H_9)_4 in ethanol solution. The transmittance of TiO_2 films with various number of the layer is measured to be 0% below 320 nm,and the three-layer TiO_2 film is of the best UV resistance in the range of 320 nm～400 nm.展开更多
Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by th...Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by the conventional hydrothermal method.Both two compounds endow short ultraviolet(UV)absorption edges(281 nm and 278 nm,respectively)and large birefringence(0.171@546 nm and 0.174@546 nm,respectively),which means that they are promising short-wave UV optical materials.Interestingly,though both of the two compounds exhibit similar 1D chained structures,and possess the same functional moieties including SbO4 seesaws and SO4 tetrahedral groups,they exhibit significantly opposite macroscopic symmetries,i.e.,compound 1 crystallizes in a centrosymmetric(CS)manner(P2_(1)/n)and compound 2 in a noncentrosymmetric(NCS)manner(P2_(1)2_(1)2_(1)),due to the size of cations[r(Rb+)=1.56 A˚,r(Cs+)=1.67 A˚]affects the orientation of SCALP of the adjacent Sb^(3+).展开更多
Electronic absorption bands of conjugated linear carbon chain molecules, namely polyynes H(C≡C)nH (n=5-7), are exploited to devise light-polarizing films applicable to the UV. Laser ablated polyynes are separated in ...Electronic absorption bands of conjugated linear carbon chain molecules, namely polyynes H(C≡C)nH (n=5-7), are exploited to devise light-polarizing films applicable to the UV. Laser ablated polyynes are separated in size and dispersed in a film of polyvinyl alcohol (PVA), which is stretched to align the trapped linear polyyne molecules inside. As a nature of the structural anisotropy, transition dipole of the UV absorption for polyyne molecules is in parallel with the molecular axis and the absorption occurs only for the electromagnetic wave having the amplitude of its electric vector along the molecular axis. Aligned and fixed orientationally in the solid PVA film, polyyne molecules act as selective absorbers of one of the polarization components of incident light at particular wavelength. Using a light source of linearly polarized UV light, whose direction of polarization is rotatable, angular dependence of the absorption intensity is investigated for the stretched PVA film containing aligned polyyne molecules and analyzed in terms of an order parameter in the theory of linear dichroism.展开更多
Finding suitable strategies to effectively enhance the optical properties of materials are the goal being pursued by researchers.Herein,cation-anion synergetic interactions strategy was proposed to develop two novel o...Finding suitable strategies to effectively enhance the optical properties of materials are the goal being pursued by researchers.Herein,cation-anion synergetic interactions strategy was proposed to develop two novel organic-inorganic hybrid antimony-based optical materials,(C_(3)H_(5)N_(2))Sb F_(2)SO_(4)(I)and(C_(5)H_(6)N)Sb F_(2)SO_(4)(Ⅱ),which were obtained by introducing Sb^(3+)cation containing stereochemically active lone-pair(SCALP)and organicπ-conjugated cations into sulphate system.The synergistic interactions of the organicπ-conjugated cations,the inorganic[SbO_(2)F_(2)]^(3-)seesaw anions and the[SO_(4)]^(2-)distorted tetrahedra anions make their ultraviolet(UV)absorption edges approach 297 and 283 nm,respectively,and raise their birefringence up to 0.193@546 nm and 0.179@546 nm,respectively.Interestingly,although the two compounds have the same stoichiometric ratio and similar one-dimensional(1D)chain structure,they show opposite macroscopic symmetry,where the NCS compound(Ⅱ)exhibits a large secondharmonic generation(SHG)response(1.6 times that of KH_(2)PO_(4)).The two reported compounds are found to be promising UV optical materials in the experimental tests.展开更多
This study reports the synthesis of oleic acid sterol ester with liquid crystalline properties and its enhanced stability and UV-blocking performance through microencapsulation.Oleic acid sterol ester was synthesized ...This study reports the synthesis of oleic acid sterol ester with liquid crystalline properties and its enhanced stability and UV-blocking performance through microencapsulation.Oleic acid sterol ester was synthesized via the esterification of phytosterol and oleic acid,whose structure was characterized using Fourier-transform infrared spectroscopy(FTIR)and mass spectrometry(MS).Its liquid crystalline behavior was confirmed via the polarized optical microscopy(POM),thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),wide-angle X-ray scattering(WAXS),and small-angle X-ray scattering(SAXS).UV absorption tests were conducted to assess the UV-blocking performance of the oleic acid sterol ester liquid crystals.To improve the stability of its liquid crystalline structure,the oleic acid sterol ester was encapsulated into microcapsules through the emulsion polymerization.SPF measurements were performed on the sunscreen formulations containing liquid crystal microcapsules.The oleic acid sterol ester displayed cholesteric liquid crystalline behavior and strong UVA absorption,which indicates its suitability as a natural UV absorber.Microencapsulation further enhanced its stability and UV-blocking properties.SPF testing showed that the formulations with microcapsules achieved an SPF value of 7.01,which surpasses the nano titanium dioxide(SPF=6.23)and significantly outperform the unencapsulated liquid crystal formulations(SPF=2.65).This study highlights the potential of microencapsulated oleic acid sterol ester as a novel UV absorber in the sunscreen formulations,offers the enhanced stability and effective UV protection,and showcases its application potential in the innovative cosmetic products.展开更多
The binding of nicotine to bovine serum albumin (BSA) was studied by UV absorption. fluorescence, and H-1 NMR methods. With the addition of nicotine, the absorption band of BSA at about 210 nm decreased gradually, mov...The binding of nicotine to bovine serum albumin (BSA) was studied by UV absorption. fluorescence, and H-1 NMR methods. With the addition of nicotine, the absorption band of BSA at about 210 nm decreased gradually, moved to longer wavelengths, and narrowed. BSA fluorescence of tryptophan residue was quenched by nicotine. The H-1 NMR peaks of nicotine moved to downfield by the addition of BSA. The experimental results showed that nicotine was capable of binding with BSA to form a 1:1 complex. BSA's high selectivity for nicotine binding suggests a unique role for this protein in the detoxification and/or transport of nicotine.展开更多
Two anti-2,4-bis（3-R-phenyl）pentane-2,4-diols （1, R = Me; 2, R = SMe） have been synthesized and were characterized by X-ray diffraction, IR and UV spectra. X-ray diffractions indicate that intra- and intermolecula...Two anti-2,4-bis（3-R-phenyl）pentane-2,4-diols （1, R = Me; 2, R = SMe） have been synthesized and were characterized by X-ray diffraction, IR and UV spectra. X-ray diffractions indicate that intra- and intermolecular hydrogen bonding interactions form one-dimensional （ID） ribbons. The adjacent infinite I D ribbons result in 3D supramolecular structures. The dihedral angles between every two benzene rings in the two diols are 31.61（12） and 31.80（7）°, respectively. UV absorption spectra of the title compounds were recorded in MeOH, C2H5OH, CH3CN, n-BuOH and cyclohexane solvents with different dielectric constants.展开更多
A new coordination compound, Ni（C6H12N4）2SO4.4H20（NSH-HMTA） （HMTA, hexamethylenetetramine, C6H12N4）, has been synthesized and its single crystals were obtained. NSH-HMTA belongs to the triclinic system, space gr...A new coordination compound, Ni（C6H12N4）2SO4.4H20（NSH-HMTA） （HMTA, hexamethylenetetramine, C6H12N4）, has been synthesized and its single crystals were obtained. NSH-HMTA belongs to the triclinic system, space group Pi with a = 9.2534（6）, b = 13.3131（2）, c = 16.0373（2） A, α = 65.981（6）, β = 89.792（3）, γ = 89.677（4）°, Mr= 880.2, Z = 2, V= 1804.6（3） A3, μ = 1.254 mm-1, F（000） = 932, R = 0.0555 （1 〉 2σ（I）） and wR = 0.1908 for 19343 observed reflections. HMTA substitutes for water molecules are located at the para-positions, forming a stretching octahedral nickel ion unit. Thermo-gravimetric analysis shows that the dehydration temperature of NSH-HMTA is about 92℃. The characteristic UV peaks are approximately 10 nm red-shifted by the absorption of octahedral HMTA complex ion units.展开更多
A series ofπ-conjugated compounds ending with 9,9-diethyl-1-phenyl-1,9-dihydrofluoreno[2,3-d]imidazole were conveniently synthesized by condensation of the key intermediate9,9-diethyl-N^(2)-phenyl-9H-fluorene-2,3-dia...A series ofπ-conjugated compounds ending with 9,9-diethyl-1-phenyl-1,9-dihydrofluoreno[2,3-d]imidazole were conveniently synthesized by condensation of the key intermediate9,9-diethyl-N^(2)-phenyl-9H-fluorene-2,3-diamine with the corresponding symmetric aryl phthalaldehydes under very mild conditions.The structures of these compounds were confirmed by^(1)H NMR,^(13)C NMR,and HRMS.Their UV-Vis spectroscopy data,fluorescent spectroscopy data,and further details of the electronic properties from cyclic voltammetry measurements and theoretical calculations were studied.Most compounds possess good fluorescence-emitting ability with quantum yield of fluorescence values in the region of 0.36-0.92 and display emission within 449-513 nm depending on the molecular nature.展开更多
Zinc oxide nanometer powders were prepared by the sol-gel process.The sol and the powders characteristic of absorbing ultraviolet light is detected by the ultraviolet spectrometer.The results indicate the concentratio...Zinc oxide nanometer powders were prepared by the sol-gel process.The sol and the powders characteristic of absorbing ultraviolet light is detected by the ultraviolet spectrometer.The results indicate the concentration of zinc acetate dihydrate in isopropyl alcohol solution and the final pH value of the aqueous sol have effect on the UV absorption of the sol. The nanometer zinc oxide has strong absorption at 200 nm～360 nm,and over 90% ultraviolet in the range of 200 nm～360 nm wavelength are absorbed.The characteristic of absorbing ultraviolet light of zinc oxide increases as the particle size of zinc oxide decreases.展开更多
Dual fluorescence and UV absorption of 2′-ethylhexyl 4-（N,N-dimethylamino）benzoate （EHDMAB） were investigated in cationic, non-ionic and anionic micelles. When EHDMAB was solubilized in different micelles, the UV...Dual fluorescence and UV absorption of 2′-ethylhexyl 4-（N,N-dimethylamino）benzoate （EHDMAB） were investigated in cationic, non-ionic and anionic micelles. When EHDMAB was solubilized in different micelles, the UV absorption of EHDMAB was enhanced. Twisted intramolecular charge transfer （TICT） emission with longer wavelength was observed in ionic micelles, whereas TICT emission with shorter wavelength was obtained in non-ionic micelles. In particular, dual fluorescence of EHDMAB was significantly quenched by the positively charged pyridinium ions arranged in the Stern layer of cationic micelles. UV radiation absorbed mainly decays via TICT emission and radiationless deactivation. The dimethylamino group of EHDMAB experiences different polar environments in ionic and non-ionic micelles according to the polarity dependence of TICT emission of EHDMAB in organic solvents. In terms of the molecular structures and sizes of EHDMAB and surfactants, each individual EHDMAB molecule should be buried in micelles with its dimethylamino group toward the polar head groups of different micelles and with its 2′-ethylhexyl chain toward the hydrophobic micellar core. Dynamic fluorescence quenching measurements of EHDMAB provide further support for the location of EHDMAB in different micelles.展开更多
基金the National Natural Science Foundation of China(No.51032005)the Fundamental Research Funds for the Central Universities(Wuhan University of Technology)+1 种基金the China Postdoctoral Science Foundation(No.2012M511285)the Fund for the Young Innovative Team(Hubei University of Education)(No.2012KQ05)
文摘60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin film with the largest UV cut-off wavelength. The sample films with CeO2：TiO2=60：40 were heated at 773 K, 873 K, 973 K for 30 min. These films are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and X-ray photoelectron spectroscopy and spectrometer （XPS）. XRD analysis proves that the addition of TiO2 to CeO2 changed the crystalline state of CeO2. But the UV absorption effect of CeO2-TiO2 films with CeO2 crystallite phase is inferior to that of the amorphous phase CeO2-TiO2 films. XPS analysis also indicates that the amorphous phase CeO2-TiO2 films have the most Ce3＋ content in these films. Amorphous phase and crystalline phase of the CeO2-TiO2 films have different effects on UV absorption of the thin films.
基金This work was financially supported by the Construct Plan of Cooperation Project from the Beijing Education Committee (No.XK100080432).
文摘The nanometer yellow iron oxide was prepared by oxidizing Fe（OH）2 with air, which was verified with XRD and TEM. The result shows that nanometer yellow iron oxide is spindle-shaped and well-distributed with a long axis of 150-200 nm and short axis of 40-50 nm. Ultraviolet （UV） transmittance of the iron oxide shows the great effect of concentration on both transparency and UV ab- sorption, and it has been proven that iron oxide with a concentration of 0.025wt% is preferred. The spectrum of XRD indicates that it is goethite. When the yellow iron is dispersed in sol, given that the wavelength of UV is less than 300 nm, its UV absorption capacity is superior to those of ZnO and TiO2. The absorption capacity of the yellow iron is less than TiO2 and more than ZnO as the wavelength of UV is 300-400 nm.
基金Supported by a grant from the Education Office of Henan Province in China (No.12A140013)
文摘Objective： The aim of our study was to discovery the different cell cycle arrest effect after different densities HeLa cells treated with Trichostatin A （TSA）. In addition, this study would find some important relationship between cycle arrest effect and UV absorption spectrum of cell. Methods： 0.2 IJM TSA was applied to act on HeLa cells of different density. Then, the cycle arrest effect and UV absorption spectrum of cells were investigated, which provide support to analyze the effect of TSA on cancer cells. Results： Cell cycle arrest effect in G0/G1 of the lower density cells was more obvious than that in other groups. The other discovery in this work was that the cellular UV absorption value was higher when the density of cultured cell was lower. Conclusion： This experiment would guide the clinical study on early or late stage cancer patients in the future. On the other hand, this work indicates when cells were arrested in G0/G1 phase, the cellular absorption value increased at the same time, so UV absorption spectrum could characterize the change of cell cycle.
文摘In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge（DBD）for applications in plasma medicine.The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen.One of the emitted wavelengths is an important resonance wavelength of nitric oxide（λ = 226.2 nm）.By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength,and measuring the change in intensity by the absorbing plasma,the concentration of nitric oxide inside the plasma can be calculated.The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm,so that a distance of about 10 cm to the respiratory tract is enough to conform to the VDI Guideline 2310.
基金financially supported by the National Natural Science Foundation of China (21072053 & 20772028) the Scientific Research Fund of Hunan Provincial Education Department (10K025)
文摘Twenty five samples of 4,4'-disubstituted stilbene derivatives were synthesized, and their UV absorption max wavelengths were determined in over 10 kinds of solvents including cyclohexane, ether, chloroform, acetonitrile and ethanol, in which 242 experimental data were recorded. The effects of substituents and solvents on the energy of their UV absorption max wavelengths were discussed. The research results showed: the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was mainly affected by their intramolecular structure (substituent effect) in a given solvent, that is, the energy is dominated by both of excited-state substituent parameter o-~c and polar substituent constant crp. While their energy was dominated by the substituent effect and solvent effect in different kinds of solvents. An equation quantifying the energy of UV absorption max wavelengths of 4,4'-disubstituted stilbenes was developed. In addition, it is found that the n-octanol/water partition coefficient (logP) is more effective than the solvatochromic dye (ET(30)) in scaling the solvent effect. The equation employed the parameter logP has a better correlation and more specific physical meaning. Further, the energies of UV absorption max wavelengths of some reported compounds were predicted by the obtained equation, which are in agreement with their experimental values.
基金supported by National Natural Science Foundation of China(grant nos.52225311 and 21975167)and the Fundamental Research Funds for Central Universities.
文摘Due to the complexity of the structure within melanin and synthetic polymers(i.e.,polydopamine,PDA),it is a challenge to regulate the ultraviolet(UV)absorption.In nature,melanocytes can biosynthesize more pheomelanins than eumelanins via protein and gene overexpression for photoprotection when the UV irradiation is enhanced.During this biosynthetic pathway,L-cystine,transported by xCT gene,can be involved to form a new monomer structure incorporating a benzothiazole group,finally resulting in the formation of UV absorption-enhanced pheomelanin.Inspired by this,we have proposed a facile strategy to regulate the UV absorption of PDA by introducing the benzimidazole(BI)unit through the thiol-Michael addition reaction during the polymerization process.It was further found that the introduction of BI units not only significantly increased the content of chromophores and auxochromes,but also effectively restricted the red-shift of the absorption spectrum via interrupting the conjugated microstructure within PDA,both of which contribute to UV absorption enhancement.These UV absorption-enhanced PDA nanoparticles could be used to fabricate bio-inspired sunscreens for efficient sun protection.This work will provide a facile strategy to regulate UV absorption of melanin-like materials and open new horizons for the design and construction of bioinspired sunscreens.
基金supported by National Research Foundation of Korea (NRF)funded by the Ministry of Education (2021R1A6A1A03039696,2022R1A2C2009412)
文摘Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible spectrum.However,their intrinsically weak light absorption and the low photoluminescence quantum yield(PLQY)restrict their performance and potential use,especially in ultraviolet(UV)wavelength light ranges.Quantum dots(QD)derived from 2D materials(2D/QD)provide efficient light absorption and emission of which energy can be tuned for desirable light wavelength.In this study,we greatly enhanced the photon absorption and PLQY of monolayer(1L)tungsten disulfide(WS_(2))in the UV range via hybridization with 2D/QD,particularly titanium nitride MXene QD(Ti_(2)N MQD)and graphitic carbon nitride QD(GCNQD).With the hybridization of MQD or GCNQD,1LWS_(2)showed a maximum PL enhancement by 15 times with 300 nm wavelength excitation,while no noticeable enhancement was observed when the excitation photon energy was less than the bandgap of the QD,indicating that UV absorption by the QD played a crucial role in enhancing the light emission of 1L-WS_(2)in our 0D/2D hybrid system.Our findings present a convenient method for enhancing the photo-response of 1L-WS_(2)to UV light and offer exciting possibilities for harvesting UV energy using 1L-TMD.
基金support from Guangdong S&T programme[2024A0505050001].
文摘Background:Long-term exposure to sunlight can lead to inflammatory responses,skin photoaging and cancers.Plant extracts can serve as effective biological UV(ultraviolet)filters for their UV absorption capacity.Red rice extract is rich in phenolic acids,flavonoids,anthocyanins and procyanins has the potential as a biological UV filter.Aims:This study aims to evaluate the potential of red rice extract as a biological UV filter.Forthurmore,exploring the ability of red rice extract to enhance SPF performance and serve as a potential substitute for chemical UV filters.Methods:Using UV absorption spectroscopy,the UV absorption performance of red rice extract was compared with that of three known UV filters.Additionally,using the Folin-Ciocalteu reagent to test the total phenolic acids content of red rice extract and the antioxidant capacity of red rice extract was verified through a 2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical clearance assay,confirming its potential as a biological UV filter.Subsequently,the photoprotective enhancement effects of red rice extract in sunscreen formulations were explored by testing the SPF value with UV2000S.Results:Experiments conducted by adding different concentrations of red rice extract to sunscreen formulations demonstrated that its photoprotective enhancement effects were positively correlated with its concentration.The addition of 1%red rice extract to both oil-in-water(O/W)and water-in-oil(W/O)sunscreen formulations demonstrated good photoprotective enhancement effects,with SPF values increasing by over 10%.Further experiments showed that 1%,3%,and 5%red rice extract could replace approximately 12.82%,19.05%,and 26.09%of traditional UV filters in sunscreen formulations,achieving similar SPF values.Conclusions:These findings suggest that red rice extract is a promising biological UV filter,capable of enhancing SPF values and serving as a viable alternative for traditional UV filters.Red rice extract can be used in sunscreen products and provide photoprotection benefit.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20772028 and No.20472019）, the Natural Science Foundation of Hunan Province （No.06JJ2002）, and the Scientific Research Fund of Hunan Provincial Education Commission.
文摘A correlation equation between the UV absorption wavenumbers of 1,4-disubstituted benzenes and the excited-state substituent constant was obtained. For 80 sorts of 1,4- disubstituted benzenes, the correlation coefficient was 0.9805, and the standard deviation was only 672.27 cm^-1. The results imply that the excited-state substituent constant can be used productively for research on UV energy of 1,4-disubstituted benzenes. The present method provides a new avenue to study the UV absorption spectra of aromatic systems with the excited-state substituent constant, and it is helpful to understand the effect of substituent electrostatic effects on the chemical and physical properties of conjugated compounds with multiple substituents in excited state.
文摘Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when heat treatment temperature is 450℃,and at 800℃,TiO_2 particle size is of below 100 nm and rutile structure is presented.In the range of 360 nm～400 nm the transmittance of TiO_2 sol increases with the increasing of the concentration of Ti(OC_4H_9)_4 in ethanol solution. The transmittance of TiO_2 films with various number of the layer is measured to be 0% below 320 nm,and the three-layer TiO_2 film is of the best UV resistance in the range of 320 nm～400 nm.
基金the National Natural Science Foundation of China(Nos.22122106,22071158,21971171)the Fundamental Research Funds from Sichuan University(No.2021SCUNL101).
文摘Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by the conventional hydrothermal method.Both two compounds endow short ultraviolet(UV)absorption edges(281 nm and 278 nm,respectively)and large birefringence(0.171@546 nm and 0.174@546 nm,respectively),which means that they are promising short-wave UV optical materials.Interestingly,though both of the two compounds exhibit similar 1D chained structures,and possess the same functional moieties including SbO4 seesaws and SO4 tetrahedral groups,they exhibit significantly opposite macroscopic symmetries,i.e.,compound 1 crystallizes in a centrosymmetric(CS)manner(P2_(1)/n)and compound 2 in a noncentrosymmetric(NCS)manner(P2_(1)2_(1)2_(1)),due to the size of cations[r(Rb+)=1.56 A˚,r(Cs+)=1.67 A˚]affects the orientation of SCALP of the adjacent Sb^(3+).
基金supported by the MEXT-Supported Program for the Strategic Research Foundation at Private Universities entitled Establishing a Best-Energy-Mix Research Center to Promote the Use of Solar Energy subsidized from the Ministry of Education, Culture, Sports, Science and Technology of Japan and Kindai University
文摘Electronic absorption bands of conjugated linear carbon chain molecules, namely polyynes H(C≡C)nH (n=5-7), are exploited to devise light-polarizing films applicable to the UV. Laser ablated polyynes are separated in size and dispersed in a film of polyvinyl alcohol (PVA), which is stretched to align the trapped linear polyyne molecules inside. As a nature of the structural anisotropy, transition dipole of the UV absorption for polyyne molecules is in parallel with the molecular axis and the absorption occurs only for the electromagnetic wave having the amplitude of its electric vector along the molecular axis. Aligned and fixed orientationally in the solid PVA film, polyyne molecules act as selective absorbers of one of the polarization components of incident light at particular wavelength. Using a light source of linearly polarized UV light, whose direction of polarization is rotatable, angular dependence of the absorption intensity is investigated for the stretched PVA film containing aligned polyyne molecules and analyzed in terms of an order parameter in the theory of linear dichroism.
基金supported by the National Natural Science Foundation of China(Nos.22122106,22071158,21971171,22305166)the Fundamental Research Funds from Sichuan University(No.2021SCUNL101)the Natural Science Foundation of Sichuan Province(No.2023NSFC1066)。
文摘Finding suitable strategies to effectively enhance the optical properties of materials are the goal being pursued by researchers.Herein,cation-anion synergetic interactions strategy was proposed to develop two novel organic-inorganic hybrid antimony-based optical materials,(C_(3)H_(5)N_(2))Sb F_(2)SO_(4)(I)and(C_(5)H_(6)N)Sb F_(2)SO_(4)(Ⅱ),which were obtained by introducing Sb^(3+)cation containing stereochemically active lone-pair(SCALP)and organicπ-conjugated cations into sulphate system.The synergistic interactions of the organicπ-conjugated cations,the inorganic[SbO_(2)F_(2)]^(3-)seesaw anions and the[SO_(4)]^(2-)distorted tetrahedra anions make their ultraviolet(UV)absorption edges approach 297 and 283 nm,respectively,and raise their birefringence up to 0.193@546 nm and 0.179@546 nm,respectively.Interestingly,although the two compounds have the same stoichiometric ratio and similar one-dimensional(1D)chain structure,they show opposite macroscopic symmetry,where the NCS compound(Ⅱ)exhibits a large secondharmonic generation(SHG)response(1.6 times that of KH_(2)PO_(4)).The two reported compounds are found to be promising UV optical materials in the experimental tests.
文摘This study reports the synthesis of oleic acid sterol ester with liquid crystalline properties and its enhanced stability and UV-blocking performance through microencapsulation.Oleic acid sterol ester was synthesized via the esterification of phytosterol and oleic acid,whose structure was characterized using Fourier-transform infrared spectroscopy(FTIR)and mass spectrometry(MS).Its liquid crystalline behavior was confirmed via the polarized optical microscopy(POM),thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),wide-angle X-ray scattering(WAXS),and small-angle X-ray scattering(SAXS).UV absorption tests were conducted to assess the UV-blocking performance of the oleic acid sterol ester liquid crystals.To improve the stability of its liquid crystalline structure,the oleic acid sterol ester was encapsulated into microcapsules through the emulsion polymerization.SPF measurements were performed on the sunscreen formulations containing liquid crystal microcapsules.The oleic acid sterol ester displayed cholesteric liquid crystalline behavior and strong UVA absorption,which indicates its suitability as a natural UV absorber.Microencapsulation further enhanced its stability and UV-blocking properties.SPF testing showed that the formulations with microcapsules achieved an SPF value of 7.01,which surpasses the nano titanium dioxide(SPF=6.23)and significantly outperform the unencapsulated liquid crystal formulations(SPF=2.65).This study highlights the potential of microencapsulated oleic acid sterol ester as a novel UV absorber in the sunscreen formulations,offers the enhanced stability and effective UV protection,and showcases its application potential in the innovative cosmetic products.
基金The National Natural Science Foundation of China Research Fund for Doctoral Program of Higher EducationProfessor Yuan Fa
文摘The binding of nicotine to bovine serum albumin (BSA) was studied by UV absorption. fluorescence, and H-1 NMR methods. With the addition of nicotine, the absorption band of BSA at about 210 nm decreased gradually, moved to longer wavelengths, and narrowed. BSA fluorescence of tryptophan residue was quenched by nicotine. The H-1 NMR peaks of nicotine moved to downfield by the addition of BSA. The experimental results showed that nicotine was capable of binding with BSA to form a 1:1 complex. BSA's high selectivity for nicotine binding suggests a unique role for this protein in the detoxification and/or transport of nicotine.
基金supported by NNSFC (21072053)the Scientific Research Fund of Hunan Provincial Education Department (10K025, 11C0527)+1 种基金the Open Foundation of Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of EducationHunan University of Science and Technology (No. LKF0901)
文摘Two anti-2,4-bis（3-R-phenyl）pentane-2,4-diols （1, R = Me; 2, R = SMe） have been synthesized and were characterized by X-ray diffraction, IR and UV spectra. X-ray diffractions indicate that intra- and intermolecular hydrogen bonding interactions form one-dimensional （ID） ribbons. The adjacent infinite I D ribbons result in 3D supramolecular structures. The dihedral angles between every two benzene rings in the two diols are 31.61（12） and 31.80（7）°, respectively. UV absorption spectra of the title compounds were recorded in MeOH, C2H5OH, CH3CN, n-BuOH and cyclohexane solvents with different dielectric constants.
基金Supported by Key Laboratory of Optoelectronic Materials Chemistry and Physics,Chinese Academy of Sciences
文摘A new coordination compound, Ni（C6H12N4）2SO4.4H20（NSH-HMTA） （HMTA, hexamethylenetetramine, C6H12N4）, has been synthesized and its single crystals were obtained. NSH-HMTA belongs to the triclinic system, space group Pi with a = 9.2534（6）, b = 13.3131（2）, c = 16.0373（2） A, α = 65.981（6）, β = 89.792（3）, γ = 89.677（4）°, Mr= 880.2, Z = 2, V= 1804.6（3） A3, μ = 1.254 mm-1, F（000） = 932, R = 0.0555 （1 〉 2σ（I）） and wR = 0.1908 for 19343 observed reflections. HMTA substitutes for water molecules are located at the para-positions, forming a stretching octahedral nickel ion unit. Thermo-gravimetric analysis shows that the dehydration temperature of NSH-HMTA is about 92℃. The characteristic UV peaks are approximately 10 nm red-shifted by the absorption of octahedral HMTA complex ion units.
基金Funded by the Natural Science Foundation of Shanghai City(No.19ZR1419700)。
文摘A series ofπ-conjugated compounds ending with 9,9-diethyl-1-phenyl-1,9-dihydrofluoreno[2,3-d]imidazole were conveniently synthesized by condensation of the key intermediate9,9-diethyl-N^(2)-phenyl-9H-fluorene-2,3-diamine with the corresponding symmetric aryl phthalaldehydes under very mild conditions.The structures of these compounds were confirmed by^(1)H NMR,^(13)C NMR,and HRMS.Their UV-Vis spectroscopy data,fluorescent spectroscopy data,and further details of the electronic properties from cyclic voltammetry measurements and theoretical calculations were studied.Most compounds possess good fluorescence-emitting ability with quantum yield of fluorescence values in the region of 0.36-0.92 and display emission within 449-513 nm depending on the molecular nature.
文摘Zinc oxide nanometer powders were prepared by the sol-gel process.The sol and the powders characteristic of absorbing ultraviolet light is detected by the ultraviolet spectrometer.The results indicate the concentration of zinc acetate dihydrate in isopropyl alcohol solution and the final pH value of the aqueous sol have effect on the UV absorption of the sol. The nanometer zinc oxide has strong absorption at 200 nm～360 nm,and over 90% ultraviolet in the range of 200 nm～360 nm wavelength are absorbed.The characteristic of absorbing ultraviolet light of zinc oxide increases as the particle size of zinc oxide decreases.
基金This work was supported by the National Natural Science Foundation of China （No.20335030） and the Innovation Foundation of Science and Technology （No.NWNU-KJCXGC-02-09）.
文摘Dual fluorescence and UV absorption of 2′-ethylhexyl 4-（N,N-dimethylamino）benzoate （EHDMAB） were investigated in cationic, non-ionic and anionic micelles. When EHDMAB was solubilized in different micelles, the UV absorption of EHDMAB was enhanced. Twisted intramolecular charge transfer （TICT） emission with longer wavelength was observed in ionic micelles, whereas TICT emission with shorter wavelength was obtained in non-ionic micelles. In particular, dual fluorescence of EHDMAB was significantly quenched by the positively charged pyridinium ions arranged in the Stern layer of cationic micelles. UV radiation absorbed mainly decays via TICT emission and radiationless deactivation. The dimethylamino group of EHDMAB experiences different polar environments in ionic and non-ionic micelles according to the polarity dependence of TICT emission of EHDMAB in organic solvents. In terms of the molecular structures and sizes of EHDMAB and surfactants, each individual EHDMAB molecule should be buried in micelles with its dimethylamino group toward the polar head groups of different micelles and with its 2′-ethylhexyl chain toward the hydrophobic micellar core. Dynamic fluorescence quenching measurements of EHDMAB provide further support for the location of EHDMAB in different micelles.
