Sc_(2)O_(3),as a host for solid-state laser gain materials,has advantage of high thermal conductivity and easy matching with activating ions,which is promising in high-power laser applications.Currently,Yb-doped Sc_(2...Sc_(2)O_(3),as a host for solid-state laser gain materials,has advantage of high thermal conductivity and easy matching with activating ions,which is promising in high-power laser applications.Currently,Yb-doped Sc_(2)O_(3) ceramics have been fabricated at very high sintering temperatures,but their optical quality and sintering process still need further improvement.In this work,5%Yb:Sc_(2)O_(3)(in mass)nano-powders were obtained by co-precipitation,and then transparent ceramics were fabricated by vacuum pre-sintering and hot isostatic pressing(HIP)post-treatment.The cubic Yb:Sc_(2)O_(3) nano-powders with good dispersity and an average crystallite of 29 nm were obtained.Influence of pre-sintering temperatures(1500-1700℃)on densification process,microstructure changes,and optical transmittance of Yb:Sc_(2)O_(3) ceramics was detected.Experimental data revealed that all samples have a uniform microstructure,while the average grain sizes increase with the increase of the sintering temperatures.Impressively,the optimum in-line transmittance of Yb:Sc_(2)O_(3) ceramics,pre-sintered at 1550℃after HIP post-treatment,reaches 78.1%(theoretical value of 80%)at 1100 nm.Spectroscopic properties of the Yb:Sc_(2)O_(3) ceramics reveal that the minimum population inversion parameterβ2 and the luminescence decay time of 5%Yb:Sc_(2)O_(3) ceramics are 0.041 and 0.49 ms,respectively,which demonstrate that the optical quality of the Yb:Sc_(2)O_(3) has been improved.Meanwhile,their best vacuum sintering temperature can be controlled down to a lower temperature(1550℃).In conclusion,Yb:Sc_(2)O_(3) nano-powders are successfully synthesized by co-precipitation method,and good optical quality transparent ceramics are fabricated by vacuum pre-sintering at 1550℃and HIP post-treatment.展开更多
Copper nitride （Cu3N） films were prepared by reactive radio frequency magnetron sputtering at various nitrogen partial pressures, and the films were annealed at different temperatures. The crystal structure of the f...Copper nitride （Cu3N） films were prepared by reactive radio frequency magnetron sputtering at various nitrogen partial pressures, and the films were annealed at different temperatures. The crystal structure of the films was identified by X-ray diffraction technique. The Cu3N films have a cubic anti-ReO3 structure, and lattice constant is 0.3855 nm. With increasing nitrogen partial pressure, the Cu3N films are strongly textured with the crystal direction [100]. The atomic force microscope images show that the films presence a smooth and compact morphology with nanocrystallites of about 70 nm in size. The films were further characterized by UV-visible spectrometer, and the optical band gap of the films was calculated from the Tauc equation. The typical value of optical band gap of the films is about 1.75 eV, and it increases with increasing nitrogen partial pressure. The thermal property of the films was measured by thermogravimetry, and the decomposition temperature of the films was about 530 K.展开更多
AIM: To study the optical property and biocompatibility of a tissue engineering cornea. METHODS: The cross-linker of N- (3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride (EDC)/ N-Hydroxysuccinimide (NHS) wa...AIM: To study the optical property and biocompatibility of a tissue engineering cornea. METHODS: The cross-linker of N- (3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride (EDC)/ N-Hydroxysuccinimide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing. RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.展开更多
A key question of the backward integration algorithm to lidar equation is how to determine the far-endboundary value. This paper develops a Constraint Inversion Algorithm (CIA) for deriving the value andthen the aeros...A key question of the backward integration algorithm to lidar equation is how to determine the far-endboundary value. This paper develops a Constraint Inversion Algorithm (CIA) for deriving the value andthen the aerosol extinction profile from lidar signals, which uses the ground-level horizontal lidar signals asthe constraint information. The smaller the wavelength is, the more sensitive to the variation of aerosol extinction to backscatter ratio solved by CIA. According to the property an algorithm is further proposed tosimultaneously retrieve the aerosol extinction profile, the size distribution and the imaginary part of its reflective index from the multi-wavelength lidar observations. CIA is tested in the inversion simulations withsatisfactory result.展开更多
SnO2 hollow microspheres were fabricated via a hydrothermal synthesis method assisting by the complex surfactant system of polyacrylamide and polyethylene glycol.Observation by field emission scanning electron microsc...SnO2 hollow microspheres were fabricated via a hydrothermal synthesis method assisting by the complex surfactant system of polyacrylamide and polyethylene glycol.Observation by field emission scanning electron microscopy （FESEM） showed the SnO2 hollow spheres were composed of nanoparticles.The growth mechanism for the formation of hollow spheres was proposed.UV spectroscopy and photoluminescence （PL） were used to investigate the optical properties of the products.The PL result showed that four peaks,containing the emission from recombination of free excitons,were observed in the photoluminescence spectrum.展开更多
Dond function basis sets have been used to calculate the molecular nonlinear optical properties which include hyperpolarizability βo , polarizability ao , and dipole moment μo for six molecules. The calculations at ...Dond function basis sets have been used to calculate the molecular nonlinear optical properties which include hyperpolarizability βo , polarizability ao , and dipole moment μo for six molecules. The calculations at the fourth-order Moller-Plesset approximation (MP4) have recovered more than 90% of the experimental values βo , comparecl to that as low as 75% by the other authors. The calculated values of αo and iuo are also in good agreement with those of experiments and superior to that from other work. It is shown that the bond functions improve the calculated results at SCF level and especially at the level of the correction of electronic correlation (MP2 and MP4).展开更多
Third-order nonlinear optical (NLO) materials have broad application prospects in high-density data storage, optical computer, modern laser technology, and other high-tech industries. The structures and frequencies of...Third-order nonlinear optical (NLO) materials have broad application prospects in high-density data storage, optical computer, modern laser technology, and other high-tech industries. The structures and frequencies of Dinaphtho[2,3-b:2’,3’-d]thiophene-5,7,12,13-tetraone (DNTTRA) and its 36 derivatives containing azobenzene were calculated by using density functional theory B3LYP and M06-2X methods at 6-311++g(d, p) level, respectively. Besides, the atomic charges of natural bond orbitals (NBO) were analyzed. The frontier orbitals and electron absorption spectra of A-G5 molecule were calculated by TD-DFT (TD-B3LYP/6-311++g(d, p) and TD-M06-2X/6-311++g(d, p)). The NLO properties were calculated by effective finite field FF method and self-compiled program. The results show that 36 molecules of these six series are D-π-A-π-D structures. The third-order NLO coefficients γ (second-order hyperpolarizability) of the D series molecules are the largest among the six series, reaching 10<sup>7</sup> atomic units (10<sup><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">-</span>33</sup> esu) of order of magnitude, showing good third-order NLO properties. Last, the third-order NLO properties of the azobenzene ring can be improved by introducing strong electron donor groups (e.g. -N(CH<sub>3</sub>)<sub>2</sub> or -NHCH<sub>3</sub>) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.展开更多
Nanostructural zinc oxide films have been synthesized via vapor phase growthby heating pure zinc powder.Scanning electron microscopy(SEM)images and X-ray diffraction(XRD)results showed that four kinds of morphologies ...Nanostructural zinc oxide films have been synthesized via vapor phase growthby heating pure zinc powder.Scanning electron microscopy(SEM)images and X-ray diffraction(XRD)results showed that four kinds of morphologies ZnO nanostructures namely nanowires,well-alignednanorods,nanofeathers and hexagonal nano-rods were formed and all of wurtzite structural crystals.The results indicated that the temperature and substrate play an important role in the formation ofdifferent morphologies of ZnO nanostructures.The photoluminescence(PL)measurement was carried outfor the well-aligned nanorods ZnO sample and blue emission peaks at 420 and 444 nm have beenobserved at room temperature.And the blue emission mechanism is discussed.展开更多
A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene] (POPNBE), was synthesized by a five-step reaction. As a result of introducing a long acyl to pyrrole at 3-position, the poly...A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene] (POPNBE), was synthesized by a five-step reaction. As a result of introducing a long acyl to pyrrole at 3-position, the polymer can be easily solved in polar solvents and be processed into films. The chemical structures of the intermediates and POPNBE were characterized by FTIR, 1H NMR, and UV-Vis-NIR spectrometries. The absorption band in the range of 400-600 nm in the UV-Vis-NIR spectrum is due to the π-π * band gap transition. The optical band gap of POPNBE obtained from the optical absorption is about 1.72 eV. The resonant third-order nonlinear optical property of POPNBE at 532 nm was studied by using the degenerate four-wave mixing(DFWM) technique. The resonant third-order nonlinear optical susceptibility of POPNBE is about 3.42×10 -8 esu.展开更多
Forty para-disubstituted benzylidene-aniline derivatives were synthesized,and their second harmonic generation(SHG)efficiency was measured by the Kurtz powder technique.The effect of the electronic property and the po...Forty para-disubstituted benzylidene-aniline derivatives were synthesized,and their second harmonic generation(SHG)efficiency was measured by the Kurtz powder technique.The effect of the electronic property and the position of the substituents on powder SHG efficiency was studied.展开更多
CdS films were prepared with chemical pyrolysis deposition (CPD) at 450℃ during film growth, and these CdS films were also annealed at different temperature from 200-500℃.The optical property of the CdS films before...CdS films were prepared with chemical pyrolysis deposition (CPD) at 450℃ during film growth, and these CdS films were also annealed at different temperature from 200-500℃.The optical property of the CdS films before and after annealing was investigated at different measuring temperature from 10K to 300K. Optical absorption spectra show that the absorption edge is towards the shorter wavelengths, and the energy band gaps deduced from the plots of (α·hν) 2 vs. hν are increased when the measuring temperature is decreased. The optical behaviors of the CdS films annealed at a certain temperature seem to have the similar tendency at different measuring temperature. Based on dE- ex/dT curve dependent on annealing temperature, some phenomena related microstructure in CdS films could be found.展开更多
The chiral sulfide Y4InSbS9 has been prepared from stoichiometric elements at 1223 K in an evacuated silica tube. It crystallizes in the chiral tetragonal space group P43212 with a = 9.8784（3）, c = 27.3106（16） A, ...The chiral sulfide Y4InSbS9 has been prepared from stoichiometric elements at 1223 K in an evacuated silica tube. It crystallizes in the chiral tetragonal space group P43212 with a = 9.8784（3）, c = 27.3106（16） A, V = 2665.04（19） A^3, Z = 8, Mr = 880.75, Dc = 4.390 g/cm^3, μ = 22.285 mm^–1, F（000） = 3200, the final R = 0.0302 and wR = 0.0669 for 2961 observed reflections with I 〉 2σ（I）. The structure features infinite helical chains of [In2Sb2S（11）^10–]∞ propagating along the c direction and they are separated by isolated Y^3＋ cations and S2– anions. UV/Vis diffuse reflectance spectroscopy study shows that its optical gap is around 1.94 eV. Density functional theory（DFT） study indicates an indirect band gap with an electronic transfer excitation of S 3p to Y 5d orbital electrons.展开更多
A novel Schiff base ligand (HL) derived from S-methyldithiocabazate and pmethoxylbenzaldehyde was prepared and characterized. The Schiff base ligand acts as a single negatively charged bidentate ligand fondng D-M-D ty...A novel Schiff base ligand (HL) derived from S-methyldithiocabazate and pmethoxylbenzaldehyde was prepared and characterized. The Schiff base ligand acts as a single negatively charged bidentate ligand fondng D-M-D type comPlex (D=donor, M=metal). Single crystal X-ray diffraction analysis of the copper(Ⅱ) complex established that the geometry around Cu (Ⅱ) is square-planar with two equivalent M-N and M-S bonds. The two phenyl rings and the coordinated plane are almost in one plane fotheng an electronic delocalization system. Their thirdorder response was also studied.展开更多
The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first...The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first-principles calculation.The calculation results indicate that(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO is a direct bandgap semiconductor with a bandgap of 1.1 eV.The Fermi surface is asymmetric and exhibits spin splitting phenomenon.The new type of dilute magnetic semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO exhibits significant light loss around 70 eV,with light reflection gradually increasing after 30 eV,and light absorption mainly occurring around 8-30 eV.These results also provide a basis for the discovery of more types of 1111 phase new dilute magnetic semiconductors in the future.展开更多
The phase diagram, growth and optical property of LaBWO6 crystal are reported. LaBWO6 crystal melts congruently at 1078 ℃. Based on the pseudo-ternary phase diagram of LaBWO6-（Li2WO4/LiF） -B203, the LaBWO6 crystals...The phase diagram, growth and optical property of LaBWO6 crystal are reported. LaBWO6 crystal melts congruently at 1078 ℃. Based on the pseudo-ternary phase diagram of LaBWO6-（Li2WO4/LiF） -B203, the LaBWO6 crystals have been firstly grown by the flux method. LaBWO6 crystal crystallizes in the orthorhombic system, space group P222 with a = 4.1, b = 10.31 and c = 21.71 A. LaBWO6 Crystal exhibits high transparency in a range from 327 to 1100 nm. The absorption edge of the crystal in the UV range is at 293 nm. The SHG efficient of LaBWO6 crystal is 0.3 times as large as that of the KDP crystal.展开更多
The influence of various alumina additions on the optical property of zirconia/alumina composite ceramics was investigated. The relative sintered densities, transmittances, color and the microstructure of the composit...The influence of various alumina additions on the optical property of zirconia/alumina composite ceramics was investigated. The relative sintered densities, transmittances, color and the microstructure of the composite ceramics were studied. The experimental results showed that the relative sintered densities and transmittances decreased with alumina addition. The lightness increased obviously but the chroma change was small. Pure zirconia nanopowders sintered densely could obtain the relatively high transmittance, while the transmittance and the lightness of slight addition changed significantly. The zirconia/alumina composite ceramics with alumina addition less than 7.5wt% could achieve the relatively stable and reliable optical properties.展开更多
Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior a...Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior and mechanical property of molecular crystals simultaneously via supramolecular salt strategy is rarely reported,which is very important to improve their photophysical behavior and softness for the fabrication of flexible light-emitting device.Herein,supramolecular salt approach has been successfully applied to synthesize two elastic organic fluorescent crystals(CMOH-Py-Cl and CMOH-Py-Br)derived from non-emissive and brittle pyridine-substituted coumarin derivative(CMOH-Py).Their elastic properties can be attributed to the prevalent presence of numerous weak interactions introduced by halogen atoms,which are beneficial to the absorption and release of mechanical energy.Furthermore,density functional theory(DFT)calculations demonstrated a narrowing of the HOMO-LUMO energy gaps from CMOH-Py to CMOH-Py-Cl/CMOH-Py-Br via supramolecular salt approach.Finally,the application of flexible crystal materials in the field of optical waveguides has been investigated.The transformation of crystals in terms of photophysical and mechanical properties,achieved by the supramolecular salt approach,offers novel insights into the design and construction of flexible crystalline materials,providing a new path for the development of next-generation smart materials.展开更多
In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural a...In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural and anthropogenic effects on marine aerosols optical properties,as well as the applicability of multi-satellite products and IMPROVE equation.The averaged aerosol optical depth(AOD500 nm)was 0.31±0.16 andÅngström exponent440–675 nm was 0.29±0.30.In offshore China,significant anthropogenic emissions affected the marine environment.In remote WPO,dust aerosols transported from northern China,Siberia,Central Asia,and those settling from the upper troposphere originating from north Africa,Arabian peninsula,and western India,were dominant.The spatial trends of AOD were opposite in the mid-latitude and southern seas of WPO.The highest AOD,0.32±0.23,appeared along the coast of South Asia at mid-latitude,decreasing from offshore seas to remote oceans.In low-latitude and equatorial seas,AOD significantly increased from coast to remote oceans.Ångström exponent dropped significantly from the coast to remote oceans as anthropogenic influence diminished across the entire WPO.Correlation analysis showed that both MODIS-C6 and Himawari AOD prod-ucts showed similar applicability in coastal urban areas,while Himawari AOD is highly recommended for coastal background and marine environment due to its finer resolution.The extinction coefficient derived from PM_(2.5) chemical compositions using IMPROVE algorithm exhibited a significant correlation(R^(2)=0.58)with the con-currently measured AOD in the absence of long-distance transport,suggesting that the IMPROVE is a reasonable proxy of the columnar average of marine aerosol extinctions free from transport influences.展开更多
Cu_(x)Ta_(2-x)O_(5) compositions were investigated for advanced thermoelectric and optical applications,using both simulations and experimental approaches.Density functional theory calculations were performed before t...Cu_(x)Ta_(2-x)O_(5) compositions were investigated for advanced thermoelectric and optical applications,using both simulations and experimental approaches.Density functional theory calculations were performed before the experimental observations to predict the trends of various parameters.Crystal structure analysis confirmed the presence of the orthorhombic Ta_(2)O_(5) phase in all the compositions.The composition and morphology demonstrated impurity-free contents with uniform and crack-free surfaces.Thermoelectric analysis depicted a decrease in Seebeck coefficient from 3.66??V·K^(-1)to 1.91??V·K^(-1)and an increase in the value of specific heat from 0.73 J·K^(-1)·kg^(-1)to 11.6 J·K^(-1)·kg^(-1)upon Cu incorporation in structure.The bandgap was found to reduce from 2.61 to 1.38 e V with Cu-induced electronic states.The real epsilon and static refractive index increased from 3.75 to 4.57 and from 1.93 to 2.11,respectively,with increment in Cu content.The enhanced parameters,focusing on the thermoelectric and optical responses,make these compositions potential candidates for advanced optoelectronic applications.展开更多
The electronic structures and optical properties of intrinsic SnO2, Zn-doped SnO2, SnO2 with Sn va- cancy （Vsn） and Zn-doped SnO2 with Sn vacancy are explored by using first-principles calculations. Zn-doped SnO2 is...The electronic structures and optical properties of intrinsic SnO2, Zn-doped SnO2, SnO2 with Sn va- cancy （Vsn） and Zn-doped SnO2 with Sn vacancy are explored by using first-principles calculations. Zn-doped SnO2 is a p-type semiconductor material, whose Fermi level shifts into the valence band when Zn atoms substitute Sn atoms, and the unoccupied states on the top of the valence band come from Zn 3d and O 2p states. Sn vacancies increase the relative hole number of Zn-doped SnO2, which results in a possible increase in the conductivity of Zn-doped SnO2. The Zn-doped SnO2 shows distinct visible light absorption, the increased absorption can be seen apparently with the presence of Sn vacancies in the crystal, and the blue-shift of optical spectra can be observed.展开更多
基金National Key R&D Program of China(2023YFE3812005)International Partnership Program of Chinese Academy of Sciences(121631KYSB20200039)+1 种基金National Center for Research and Development(WPC2/1/SCAPOL/2021)Chinese Academy of Sciences President’s International Fellowship Initiative(2024VEA0005,2024VEA0014)。
文摘Sc_(2)O_(3),as a host for solid-state laser gain materials,has advantage of high thermal conductivity and easy matching with activating ions,which is promising in high-power laser applications.Currently,Yb-doped Sc_(2)O_(3) ceramics have been fabricated at very high sintering temperatures,but their optical quality and sintering process still need further improvement.In this work,5%Yb:Sc_(2)O_(3)(in mass)nano-powders were obtained by co-precipitation,and then transparent ceramics were fabricated by vacuum pre-sintering and hot isostatic pressing(HIP)post-treatment.The cubic Yb:Sc_(2)O_(3) nano-powders with good dispersity and an average crystallite of 29 nm were obtained.Influence of pre-sintering temperatures(1500-1700℃)on densification process,microstructure changes,and optical transmittance of Yb:Sc_(2)O_(3) ceramics was detected.Experimental data revealed that all samples have a uniform microstructure,while the average grain sizes increase with the increase of the sintering temperatures.Impressively,the optimum in-line transmittance of Yb:Sc_(2)O_(3) ceramics,pre-sintered at 1550℃after HIP post-treatment,reaches 78.1%(theoretical value of 80%)at 1100 nm.Spectroscopic properties of the Yb:Sc_(2)O_(3) ceramics reveal that the minimum population inversion parameterβ2 and the luminescence decay time of 5%Yb:Sc_(2)O_(3) ceramics are 0.041 and 0.49 ms,respectively,which demonstrate that the optical quality of the Yb:Sc_(2)O_(3) has been improved.Meanwhile,their best vacuum sintering temperature can be controlled down to a lower temperature(1550℃).In conclusion,Yb:Sc_(2)O_(3) nano-powders are successfully synthesized by co-precipitation method,and good optical quality transparent ceramics are fabricated by vacuum pre-sintering at 1550℃and HIP post-treatment.
基金supported by the National Natural Science Foundation of China (Garnt No. 11064003)the Guangxi Natural Science Foundation of China(2010GXNSFA013122)
文摘Copper nitride （Cu3N） films were prepared by reactive radio frequency magnetron sputtering at various nitrogen partial pressures, and the films were annealed at different temperatures. The crystal structure of the films was identified by X-ray diffraction technique. The Cu3N films have a cubic anti-ReO3 structure, and lattice constant is 0.3855 nm. With increasing nitrogen partial pressure, the Cu3N films are strongly textured with the crystal direction [100]. The atomic force microscope images show that the films presence a smooth and compact morphology with nanocrystallites of about 70 nm in size. The films were further characterized by UV-visible spectrometer, and the optical band gap of the films was calculated from the Tauc equation. The typical value of optical band gap of the films is about 1.75 eV, and it increases with increasing nitrogen partial pressure. The thermal property of the films was measured by thermogravimetry, and the decomposition temperature of the films was about 530 K.
基金Scientific and Technological Research Projects of Educational Committee of Liaoning Province of China(No.2008S243)
文摘AIM: To study the optical property and biocompatibility of a tissue engineering cornea. METHODS: The cross-linker of N- (3-Dimethylaminoropyl)-N'ethylcarbodiimide hydrochloride (EDC)/ N-Hydroxysuccinimide (NHS) was mixed with Type I collagen at 10% (weight/volume). The final solution was molded to the shape of a corneal contact lens. The collagen concentrations of 10%, 12.5%, 15%, 17.5% and 20% artificial corneas were tested by UV/vis-spectroscopy for their transparency compared with normal rat cornea. 10-0 sutures were knotted on the edges of substitute to measure the corneal buttons's mechanical properties. Normal rat corneal tissue primary culture on the collagen scaffold was observed in 4 weeks. Histopathologic examinations were performed after 4 weeks of in vitro culturing. RESULTS: The collagen scaffold appearance was similar to that of soft contact lens. With the increase of collagen concentration, the transparency of artificial corneal buttons was diminished, but the toughness of the scaffold was enhanced. The scaffold transparency in the 10% concentration collagen group resembled normal rat cornea. To knot and embed the scaffold under the microscope, 20% concentration collagen group was more effective during implantation than lower concentrations of collagen group. In the first 3 weeks, corneal cell proliferation was highly active. The shapes of cells that grew on the substitute had no significant difference when compared with the cells before they were moved to the scaffold. However, on the fortieth day, most cells detached from the scaffold and died. Histopathologic examination of the primary culture scaffold revealed well grown corneal cells tightly attached to the scaffold in the former culturing. CONCLUSION: Collagen scaffold can be molded to the shape of soft contact corneal lens with NHS/EDC. The biological stability and biocompatibility of collagen from animal species may be used as material in preparing to engineer artificial corneal scaffold.
文摘A key question of the backward integration algorithm to lidar equation is how to determine the far-endboundary value. This paper develops a Constraint Inversion Algorithm (CIA) for deriving the value andthen the aerosol extinction profile from lidar signals, which uses the ground-level horizontal lidar signals asthe constraint information. The smaller the wavelength is, the more sensitive to the variation of aerosol extinction to backscatter ratio solved by CIA. According to the property an algorithm is further proposed tosimultaneously retrieve the aerosol extinction profile, the size distribution and the imaginary part of its reflective index from the multi-wavelength lidar observations. CIA is tested in the inversion simulations withsatisfactory result.
基金Funded by the Basic Research Program of Henan Province of China (No.102300410172)the Natural Science Program of Luoyang Institute of Science and Technology (No. 2009YZ04)+1 种基金the Program for Innovation Team of the Ministry of Education of China (PCSIRT0644)the National Natural Science Foundation of China (A3 Foresight Project No. 50821140308)
文摘SnO2 hollow microspheres were fabricated via a hydrothermal synthesis method assisting by the complex surfactant system of polyacrylamide and polyethylene glycol.Observation by field emission scanning electron microscopy （FESEM） showed the SnO2 hollow spheres were composed of nanoparticles.The growth mechanism for the formation of hollow spheres was proposed.UV spectroscopy and photoluminescence （PL） were used to investigate the optical properties of the products.The PL result showed that four peaks,containing the emission from recombination of free excitons,were observed in the photoluminescence spectrum.
文摘Dond function basis sets have been used to calculate the molecular nonlinear optical properties which include hyperpolarizability βo , polarizability ao , and dipole moment μo for six molecules. The calculations at the fourth-order Moller-Plesset approximation (MP4) have recovered more than 90% of the experimental values βo , comparecl to that as low as 75% by the other authors. The calculated values of αo and iuo are also in good agreement with those of experiments and superior to that from other work. It is shown that the bond functions improve the calculated results at SCF level and especially at the level of the correction of electronic correlation (MP2 and MP4).
文摘Third-order nonlinear optical (NLO) materials have broad application prospects in high-density data storage, optical computer, modern laser technology, and other high-tech industries. The structures and frequencies of Dinaphtho[2,3-b:2’,3’-d]thiophene-5,7,12,13-tetraone (DNTTRA) and its 36 derivatives containing azobenzene were calculated by using density functional theory B3LYP and M06-2X methods at 6-311++g(d, p) level, respectively. Besides, the atomic charges of natural bond orbitals (NBO) were analyzed. The frontier orbitals and electron absorption spectra of A-G5 molecule were calculated by TD-DFT (TD-B3LYP/6-311++g(d, p) and TD-M06-2X/6-311++g(d, p)). The NLO properties were calculated by effective finite field FF method and self-compiled program. The results show that 36 molecules of these six series are D-π-A-π-D structures. The third-order NLO coefficients γ (second-order hyperpolarizability) of the D series molecules are the largest among the six series, reaching 10<sup>7</sup> atomic units (10<sup><span style="color:#4F4F4F;font-family:-apple-system, " font-size:14px;white-space:normal;background-color:#ffffff;"="">-</span>33</sup> esu) of order of magnitude, showing good third-order NLO properties. Last, the third-order NLO properties of the azobenzene ring can be improved by introducing strong electron donor groups (e.g. -N(CH<sub>3</sub>)<sub>2</sub> or -NHCH<sub>3</sub>) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.
基金Supported by the National Natural Science Foundation of China(9975035)
文摘Nanostructural zinc oxide films have been synthesized via vapor phase growthby heating pure zinc powder.Scanning electron microscopy(SEM)images and X-ray diffraction(XRD)results showed that four kinds of morphologies ZnO nanostructures namely nanowires,well-alignednanorods,nanofeathers and hexagonal nano-rods were formed and all of wurtzite structural crystals.The results indicated that the temperature and substrate play an important role in the formation ofdifferent morphologies of ZnO nanostructures.The photoluminescence(PL)measurement was carried outfor the well-aligned nanorods ZnO sample and blue emission peaks at 420 and 444 nm have beenobserved at room temperature.And the blue emission mechanism is discussed.
文摘A novel soluble π-conjugated polymer, poly[(3-octanoylpyrrole-2,5-diyl)-p-nitrobenzylidene] (POPNBE), was synthesized by a five-step reaction. As a result of introducing a long acyl to pyrrole at 3-position, the polymer can be easily solved in polar solvents and be processed into films. The chemical structures of the intermediates and POPNBE were characterized by FTIR, 1H NMR, and UV-Vis-NIR spectrometries. The absorption band in the range of 400-600 nm in the UV-Vis-NIR spectrum is due to the π-π * band gap transition. The optical band gap of POPNBE obtained from the optical absorption is about 1.72 eV. The resonant third-order nonlinear optical property of POPNBE at 532 nm was studied by using the degenerate four-wave mixing(DFWM) technique. The resonant third-order nonlinear optical susceptibility of POPNBE is about 3.42×10 -8 esu.
文摘Forty para-disubstituted benzylidene-aniline derivatives were synthesized,and their second harmonic generation(SHG)efficiency was measured by the Kurtz powder technique.The effect of the electronic property and the position of the substituents on powder SHG efficiency was studied.
文摘CdS films were prepared with chemical pyrolysis deposition (CPD) at 450℃ during film growth, and these CdS films were also annealed at different temperature from 200-500℃.The optical property of the CdS films before and after annealing was investigated at different measuring temperature from 10K to 300K. Optical absorption spectra show that the absorption edge is towards the shorter wavelengths, and the energy band gaps deduced from the plots of (α·hν) 2 vs. hν are increased when the measuring temperature is decreased. The optical behaviors of the CdS films annealed at a certain temperature seem to have the similar tendency at different measuring temperature. Based on dE- ex/dT curve dependent on annealing temperature, some phenomena related microstructure in CdS films could be found.
基金Supported by the National Natural Science Foundation of China(Nos.21201185 and 21661037)the Natural Science Foundation of Chongqing(Nos.cstc2013jcyjA50033 and cstc2015jcyjA0317)+2 种基金the Natural Science Foundation of Guizhou Province(Nos.JLKZS[2014]13 and[2014]42)the Project Foundation of Chongqing University of Education(No.16xjpt08)the Natural Science Foundation of State Key Laboratory of Structural Chemistry(No.20140004)
文摘The chiral sulfide Y4InSbS9 has been prepared from stoichiometric elements at 1223 K in an evacuated silica tube. It crystallizes in the chiral tetragonal space group P43212 with a = 9.8784（3）, c = 27.3106（16） A, V = 2665.04（19） A^3, Z = 8, Mr = 880.75, Dc = 4.390 g/cm^3, μ = 22.285 mm^–1, F（000） = 3200, the final R = 0.0302 and wR = 0.0669 for 2961 observed reflections with I 〉 2σ（I）. The structure features infinite helical chains of [In2Sb2S（11）^10–]∞ propagating along the c direction and they are separated by isolated Y^3＋ cations and S2– anions. UV/Vis diffuse reflectance spectroscopy study shows that its optical gap is around 1.94 eV. Density functional theory（DFT） study indicates an indirect band gap with an electronic transfer excitation of S 3p to Y 5d orbital electrons.
文摘A novel Schiff base ligand (HL) derived from S-methyldithiocabazate and pmethoxylbenzaldehyde was prepared and characterized. The Schiff base ligand acts as a single negatively charged bidentate ligand fondng D-M-D type comPlex (D=donor, M=metal). Single crystal X-ray diffraction analysis of the copper(Ⅱ) complex established that the geometry around Cu (Ⅱ) is square-planar with two equivalent M-N and M-S bonds. The two phenyl rings and the coordinated plane are almost in one plane fotheng an electronic delocalization system. Their thirdorder response was also studied.
文摘The band structure,DOSs,and optical properties of(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO,including dielectric function,absorption function,reflection function,and energy loss spectrum were studied by using the first-principles calculation.The calculation results indicate that(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO is a direct bandgap semiconductor with a bandgap of 1.1 eV.The Fermi surface is asymmetric and exhibits spin splitting phenomenon.The new type of dilute magnetic semiconductor(Y_(0.75)Ca_(0.25))(Cu_(0.75)Mn_(0.25))SO exhibits significant light loss around 70 eV,with light reflection gradually increasing after 30 eV,and light absorption mainly occurring around 8-30 eV.These results also provide a basis for the discovery of more types of 1111 phase new dilute magnetic semiconductors in the future.
基金Supported by the NNSFC (No.61275177)the NSF of Fujian Province (No.2012I0011)
文摘The phase diagram, growth and optical property of LaBWO6 crystal are reported. LaBWO6 crystal melts congruently at 1078 ℃. Based on the pseudo-ternary phase diagram of LaBWO6-（Li2WO4/LiF） -B203, the LaBWO6 crystals have been firstly grown by the flux method. LaBWO6 crystal crystallizes in the orthorhombic system, space group P222 with a = 4.1, b = 10.31 and c = 21.71 A. LaBWO6 Crystal exhibits high transparency in a range from 327 to 1100 nm. The absorption edge of the crystal in the UV range is at 293 nm. The SHG efficient of LaBWO6 crystal is 0.3 times as large as that of the KDP crystal.
基金Funded by the National High-Tech Research and Development Program of China (863 Program) (No. 2006AA03Z440)
文摘The influence of various alumina additions on the optical property of zirconia/alumina composite ceramics was investigated. The relative sintered densities, transmittances, color and the microstructure of the composite ceramics were studied. The experimental results showed that the relative sintered densities and transmittances decreased with alumina addition. The lightness increased obviously but the chroma change was small. Pure zirconia nanopowders sintered densely could obtain the relatively high transmittance, while the transmittance and the lightness of slight addition changed significantly. The zirconia/alumina composite ceramics with alumina addition less than 7.5wt% could achieve the relatively stable and reliable optical properties.
基金supported by the National Natural Science Foundation of China(Nos.22205105,61874053,22075136)National Key Basic Research Program of China(No.2020YFA0709900)Jiangsu Provincial Postgraduate Scientific Research Innovation Program(No.KYCX24_1649).
文摘Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior and mechanical property of molecular crystals simultaneously via supramolecular salt strategy is rarely reported,which is very important to improve their photophysical behavior and softness for the fabrication of flexible light-emitting device.Herein,supramolecular salt approach has been successfully applied to synthesize two elastic organic fluorescent crystals(CMOH-Py-Cl and CMOH-Py-Br)derived from non-emissive and brittle pyridine-substituted coumarin derivative(CMOH-Py).Their elastic properties can be attributed to the prevalent presence of numerous weak interactions introduced by halogen atoms,which are beneficial to the absorption and release of mechanical energy.Furthermore,density functional theory(DFT)calculations demonstrated a narrowing of the HOMO-LUMO energy gaps from CMOH-Py to CMOH-Py-Cl/CMOH-Py-Br via supramolecular salt approach.Finally,the application of flexible crystal materials in the field of optical waveguides has been investigated.The transformation of crystals in terms of photophysical and mechanical properties,achieved by the supramolecular salt approach,offers novel insights into the design and construction of flexible crystalline materials,providing a new path for the development of next-generation smart materials.
基金supported by the CAS Strategic Priority Research Program(No.XDB0760102),the Ministry of Science and Technology of China(No.2022YFF0802501)the Major Science and Technology Infrastructure Maintenance and Transformation Project of the Chinese Academy of Sciences,Shanghai Science and Technology Innovation Action Plan-Phospherus Project(No.23YF1426200)the National Key Research and Development Program of China(No.2024YFE0212200).
文摘In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural and anthropogenic effects on marine aerosols optical properties,as well as the applicability of multi-satellite products and IMPROVE equation.The averaged aerosol optical depth(AOD500 nm)was 0.31±0.16 andÅngström exponent440–675 nm was 0.29±0.30.In offshore China,significant anthropogenic emissions affected the marine environment.In remote WPO,dust aerosols transported from northern China,Siberia,Central Asia,and those settling from the upper troposphere originating from north Africa,Arabian peninsula,and western India,were dominant.The spatial trends of AOD were opposite in the mid-latitude and southern seas of WPO.The highest AOD,0.32±0.23,appeared along the coast of South Asia at mid-latitude,decreasing from offshore seas to remote oceans.In low-latitude and equatorial seas,AOD significantly increased from coast to remote oceans.Ångström exponent dropped significantly from the coast to remote oceans as anthropogenic influence diminished across the entire WPO.Correlation analysis showed that both MODIS-C6 and Himawari AOD prod-ucts showed similar applicability in coastal urban areas,while Himawari AOD is highly recommended for coastal background and marine environment due to its finer resolution.The extinction coefficient derived from PM_(2.5) chemical compositions using IMPROVE algorithm exhibited a significant correlation(R^(2)=0.58)with the con-currently measured AOD in the absence of long-distance transport,suggesting that the IMPROVE is a reasonable proxy of the columnar average of marine aerosol extinctions free from transport influences.
基金the Deanship of Research and Graduate Studies at King Khalid University,Saudi Arabia,for funding this study through the Large Groups Project(Grant No.RGP2/2/47)the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through project number NBU-FFR-2025-1902-02。
文摘Cu_(x)Ta_(2-x)O_(5) compositions were investigated for advanced thermoelectric and optical applications,using both simulations and experimental approaches.Density functional theory calculations were performed before the experimental observations to predict the trends of various parameters.Crystal structure analysis confirmed the presence of the orthorhombic Ta_(2)O_(5) phase in all the compositions.The composition and morphology demonstrated impurity-free contents with uniform and crack-free surfaces.Thermoelectric analysis depicted a decrease in Seebeck coefficient from 3.66??V·K^(-1)to 1.91??V·K^(-1)and an increase in the value of specific heat from 0.73 J·K^(-1)·kg^(-1)to 11.6 J·K^(-1)·kg^(-1)upon Cu incorporation in structure.The bandgap was found to reduce from 2.61 to 1.38 e V with Cu-induced electronic states.The real epsilon and static refractive index increased from 3.75 to 4.57 and from 1.93 to 2.11,respectively,with increment in Cu content.The enhanced parameters,focusing on the thermoelectric and optical responses,make these compositions potential candidates for advanced optoelectronic applications.
基金supported by the National Natural Science Foundation of China(No.10974077)the Innovation Project of Shandong Graduate Education,China(No.SDYY13093)
文摘The electronic structures and optical properties of intrinsic SnO2, Zn-doped SnO2, SnO2 with Sn va- cancy （Vsn） and Zn-doped SnO2 with Sn vacancy are explored by using first-principles calculations. Zn-doped SnO2 is a p-type semiconductor material, whose Fermi level shifts into the valence band when Zn atoms substitute Sn atoms, and the unoccupied states on the top of the valence band come from Zn 3d and O 2p states. Sn vacancies increase the relative hole number of Zn-doped SnO2, which results in a possible increase in the conductivity of Zn-doped SnO2. The Zn-doped SnO2 shows distinct visible light absorption, the increased absorption can be seen apparently with the presence of Sn vacancies in the crystal, and the blue-shift of optical spectra can be observed.
