This paper presents a method for retrieving optical parameters from volcanic sulfate aerosols from the AHI radiometer on board the Himawari-8 satellite.The proposed method is based on optical models for various mixtur...This paper presents a method for retrieving optical parameters from volcanic sulfate aerosols from the AHI radiometer on board the Himawari-8 satellite.The proposed method is based on optical models for various mixtures of aerosol components from volcanic clouds,including ash particles,ice crystals,water drops,and sulfate aerosol droplets.The application of multi-component optical models of various aerosol compositions allows for the optical thickness and mass loading of sulfate aerosol to be estimated in the sulfuric cloud formed after the Karymsky volcano eruption on 3 November 2021.A comprehensive analysis of the brightness temperatures of the sulfuric cloud in the infrared bands was performed,which revealed that the cloud was composed of a mixture of sulfate aerosol and water droplets.Using models of various aerosol compositions allows for the satellite-based estimation of optical parameters not only for sulfate aerosol but also for the whole aerosol mixture.展开更多
The energetics, electronic structures, and optical properties of several neutral vacancies for γ-Si3N4 are studied based on density function theory within the generalized gradient approximation. The binding and forma...The energetics, electronic structures, and optical properties of several neutral vacancies for γ-Si3N4 are studied based on density function theory within the generalized gradient approximation. The binding and formation energies of nitrogen vacancy are smaller than that of silicon vacancies, implying that nitrogen vacancy can be easily formed in γ-Si3N4.Corresponding density of states of different point vacancies is analyzed. We concluded that the neutral silicon vacancies introduce the p-type carriers into the system, whereas single nitrogen vacancy leads to an n-type semiconductor. The results show indirect semiconductor of nitrogen vacancy for γ-Si3N4. The effects of optical properties are discussed on single vacancies for γ-Si3N4. For silicon vacancies, the materials have much higher static dielectric constants than these of nitrogen vacancy and perfect γ-Si3N4. The single nitrogen vacancy for γ-Si3N4 has no effects on absorption and reflection in visible and infrared light. For silicon vacancy, it is significantly increased.展开更多
本文基于密度泛函理论(DFT)的第一性原理计算了W、Mn、V、Ti替位掺杂二维MoSi_(2)N_(4)后的几何结构、电子结构以及光学性质的变化.电子结构分析表明W、Mn、W、Ti替位掺杂二维MoSi_(2)N_(4)后的禁带宽度分别为1.806 e V、1.003 e V、1.2...本文基于密度泛函理论(DFT)的第一性原理计算了W、Mn、V、Ti替位掺杂二维MoSi_(2)N_(4)后的几何结构、电子结构以及光学性质的变化.电子结构分析表明W、Mn、W、Ti替位掺杂二维MoSi_(2)N_(4)后的禁带宽度分别为1.806 e V、1.003 e V、1.218 e V和1.373 e V;四种过渡金属掺杂后MoSi_(2)N_(4)的带隙类型没有发生改变,均为间接带隙半导体;W掺杂后的杂质能级靠近价带顶,费米能级靠近价带顶,为p型半导体,杂质能级为受主能级;Mn掺杂后的杂质能级靠近导带底,费米能级靠近导带底,为n型半导体;V和Ti掺杂后杂质能级位于费米能级附近,为复合中心;光学性质分析表明,在2 e V~4 e V的能量区间内,W掺杂结构的吸收波长为336 nm,体系发生红移;Mn、V和Ti替位掺杂后的吸收波长分别为320 nm、358 nm和338 nm,且掺杂体系均发生蓝移.展开更多
Neuromyelitis optica is an inflammatory demyelinating disease of the central nervous system that differs from multiple sclerosis.Over the past 20 years,the search for biomarke rs for neuromyelitis optica has been ongo...Neuromyelitis optica is an inflammatory demyelinating disease of the central nervous system that differs from multiple sclerosis.Over the past 20 years,the search for biomarke rs for neuromyelitis optica has been ongoing.Here,we used a bibliometric approach to analyze the main research focus in the field of biomarkers for neuromyelitis optica.Research in this area is consistently increasing,with China and the United States leading the way on the number of studies conducted.The Mayo Clinic is a highly reputable institution in the United States,and was identified as the most authoritative institution in this field.Furthermore,Professor Wingerchuk from the Mayo Clinic was the most authoritative expe rt in this field.Keyword analysis revealed that the terms "neuro myelitis optica"(261 times), "multiple sclerosis"(220 times), "neuromyelitis optica spectrum disorder"(132 times), "aquaporin4"(99 times),and "optical neuritis"(87 times) were the most frequently used keywords in literature related to this field.Comprehensive analysis of the classical literature showed that the majority of publications provide conclusive research evidence supporting the use of aquaporin-4-IgG and neuromyelitis optica-IgG to effectively diagnose and differentiate neuromyelitis optica from multiple sclerosis.Furthermore,aquaporin-4-IgG has emerged as a highly specific diagnostic biomarker for neuromyelitis optica spectrum disorder.Myelin oligodendrocyte glycoprotein-IgG is a diagnostic biomarke r for myelin oligodendrocyte glycoprotein antibody-associated disease.Recent biomarkers for neuromyelitis optica in clude cerebrospinal fluid immunological biomarkers such as glial fibrillary acidic protein,serum astrocyte damage biomarkers like FAM19A5,serum albumin,and gammaaminobutyric acid.The latest prospective clinical trials are exploring the potential of these biomarkers.Preliminary results indicate that glial fibrillary acidic protein is emerging as a promising candidate biomarker for neuromyelitis optica spectrum disorder.The ultimate goal of future research is to identify non-invasive biomarkers with high sensitivity,specificity,and safety for the accurate diagnosis of neuro myelitis optica.展开更多
A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichl...A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.展开更多
Nickel molybdate(NiMoO4)nanoparticles(NPs)were synthesized by sol-gel method.Utilizing water as solvent providescrystalline nanostructures.These nanocrystals were structurally characterized by X-ray diffraction,energy...Nickel molybdate(NiMoO4)nanoparticles(NPs)were synthesized by sol-gel method.Utilizing water as solvent providescrystalline nanostructures.These nanocrystals were structurally characterized by X-ray diffraction,energy dispersive X-ray analysis(EDX),and Fourier transform infrared spectra.Compositional stoichiometry was confirmed by EDX technique.The size and shapewere observed by scanning electron microscopy(SEM)and transmission electron microscope(TEM).It was found that the obtainedNPs were pure and single phase crystalline with monoclinic structure.The optical properties were studied by ultraviolet-visiblediffuse reflectance spectroscopy(UV-Vis-DRS)and photoluminescence(PL)measurements at room temperature.The magneticproperties were studied by vibrating sample magnetometer(VSM)and results showed superparamagnetic behavior of the obtainednanoparticles.Photocatalytic activity of NiMoO4was studied.The photocatalytic activity of NiMoO4was enhanced with the additionof TiO2.The catalysts NiMoO4,TiO2and NiMoO4-TiO2nanocomposites(NC)were tested for photocatalytic degradation(PCD)of4-chlorophenol(4-CP).It was found that PCD efficiency of NiMoO4-TiO2NC was higher than that of pure NiMoO4and TiO2.展开更多
The electronic structures, the effective masses, and optical properties of spinel CdCr_2S_4 are studied by using the fullpotential linearized augmented planewave method and a modified Becke–Johnson exchange functiona...The electronic structures, the effective masses, and optical properties of spinel CdCr_2S_4 are studied by using the fullpotential linearized augmented planewave method and a modified Becke–Johnson exchange functional within the densityfunctional theory. Most importantly, the effects of the spin–orbit coupling（SOC） on the electronic structures and carrier effective masses are investigated. The calculated band structure shows a direct band gap. The electronic effective mass and the hole effective mass are analytically determined by reproducing the calculated band structures near the BZ center.SOC substantially changes the valence band top and the hole effective masses. In addition, we calculated the corresponding optical properties of the spinel structure CdCr_2S_4. These should be useful to deeply understand spinel CdCr_2S_4 as a ferromagnetic semiconductor for possible semiconductor spintronic applications.展开更多
High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared...High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.展开更多
BACKGROUND Radionuclides produce Cherenkov radiation(CR),which can potentially activate photosensitizers(PSs)in phototherapy.Several groups have studied Cherenkov energy transfer to PSs using optical imaging;however,c...BACKGROUND Radionuclides produce Cherenkov radiation(CR),which can potentially activate photosensitizers(PSs)in phototherapy.Several groups have studied Cherenkov energy transfer to PSs using optical imaging;however,cost-effectively identifying whether PSs are excited by radionuclide-derived CR and detecting fluorescence emission from excited PSs remain a challenge.Many laboratories face the need for expensive dedicated equipment.AIM To cost-effectively confirm whether PSs are excited by radionuclide-derived CR and distinguish fluorescence emission from excited PSs.METHODS The absorbance and fluorescence spectra of PSs were measured using a microplate reader and fluorescence spectrometer to examine the photo-physical properties of PSs.To mitigate the need for expensive dedicated equipment and achieve the aim of the study,we developed a method that utilizes a chargecoupled device optical imaging system and appropriate long-pass filters of different wavelengths(manual sequential application of long-pass filters of 515,580,645,700,750,and 800 nm).Tetrakis(4-carboxyphenyl)porphyrin(TCPP)was utilized as a model PS.Different doses of copper-64(^(64)CuCl_(2))(4,2,and 1 mCi)were used as CR-producing radionuclides.Imaging and data acquisition were performed 0.5 h after sample preparation.Differential image analysis was conducted by using ImageJ software(National Institutes of Health)to visually evaluate TCPP fluorescence.RESULTS The maximum absorbance of TCPP was at 390-430 nm,and the emission peak was at 670 nm.The CR and CRinduced TCPP emissions were observed using the optical imaging system and the high-transmittance long-pass filters described above.The emission spectra of TCPP with a peak in the 645-700 nm window were obtained by calculation and subtraction based on the serial signal intensity(total flux)difference between^(64)CuCl_(2)+TCPP and^(64)CuCl_(2).Moreover,the differential fluorescence images of TCPP were obtained by subtracting the^(64)CuCl_(2)image from the^(64)CuCl_(2)+TCPP image.The experimental results considering different^(64)CuCl_(2)doses showed a dosedependent trend.These results demonstrate that a bioluminescence imaging device coupled with different longpass filters and subtraction image processing can confirm the emission spectra and differential fluorescence images of CR-induced TCPP.CONCLUSION This simple method identifies the PS fluorescence emission generated by radionuclide-derived CR and can contribute to accelerating the development of Cherenkov energy transfer imaging and the discovery of new PSs.展开更多
We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho：GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.0...We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho：GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.05 W, corresponding to a slope efficiency of 74.6%. The ZGP-OPO laser produces 4.2 ns mid-infrared pulses at a pulse repetition rate of 5 kHz. In addition, we obtain 0.8 um of tunable range for the signal wave and 2.1 um of tunable range for the idler wave.展开更多
The electronic structure and optical properties of novel Na-hP4 high pressure phase at different pressures(260,320,400 and 600 GPa)were investigated by the density functional theory(DFT)with the generalized gradient a...The electronic structure and optical properties of novel Na-hP4 high pressure phase at different pressures(260,320,400 and 600 GPa)were investigated by the density functional theory(DFT)with the generalized gradient approximation(GGA)for the exchange and correlation energy.The band structure along the higher symmetry axes in the Brillouin zone,the density of states(DOS) and the partial density of states(PDOS)were presented.The band gap increases and the energy band expands to some extent with the pressure increasing.The dielectric function,reflectivity,energy-loss function,optical absorption coefficient,optical conductivity, refractive index and extinction coefficient were calculated for discussing the optical properties of Na-hP4 high pressure phase at different pressures.展开更多
基金The studies were carried out using the resources of the Center for Shared Use of Scientific Equipment“Center for Processing and Storage of Scientific Data of the Far Eastern Branch of the Russian Academy of Sciences”(Sorokin et al.,2017)(Project No.075-15-2021-663).
文摘This paper presents a method for retrieving optical parameters from volcanic sulfate aerosols from the AHI radiometer on board the Himawari-8 satellite.The proposed method is based on optical models for various mixtures of aerosol components from volcanic clouds,including ash particles,ice crystals,water drops,and sulfate aerosol droplets.The application of multi-component optical models of various aerosol compositions allows for the optical thickness and mass loading of sulfate aerosol to be estimated in the sulfuric cloud formed after the Karymsky volcano eruption on 3 November 2021.A comprehensive analysis of the brightness temperatures of the sulfuric cloud in the infrared bands was performed,which revealed that the cloud was composed of a mixture of sulfate aerosol and water droplets.Using models of various aerosol compositions allows for the satellite-based estimation of optical parameters not only for sulfate aerosol but also for the whole aerosol mixture.
文摘The energetics, electronic structures, and optical properties of several neutral vacancies for γ-Si3N4 are studied based on density function theory within the generalized gradient approximation. The binding and formation energies of nitrogen vacancy are smaller than that of silicon vacancies, implying that nitrogen vacancy can be easily formed in γ-Si3N4.Corresponding density of states of different point vacancies is analyzed. We concluded that the neutral silicon vacancies introduce the p-type carriers into the system, whereas single nitrogen vacancy leads to an n-type semiconductor. The results show indirect semiconductor of nitrogen vacancy for γ-Si3N4. The effects of optical properties are discussed on single vacancies for γ-Si3N4. For silicon vacancies, the materials have much higher static dielectric constants than these of nitrogen vacancy and perfect γ-Si3N4. The single nitrogen vacancy for γ-Si3N4 has no effects on absorption and reflection in visible and infrared light. For silicon vacancy, it is significantly increased.
文摘本文基于密度泛函理论(DFT)的第一性原理计算了W、Mn、V、Ti替位掺杂二维MoSi_(2)N_(4)后的几何结构、电子结构以及光学性质的变化.电子结构分析表明W、Mn、W、Ti替位掺杂二维MoSi_(2)N_(4)后的禁带宽度分别为1.806 e V、1.003 e V、1.218 e V和1.373 e V;四种过渡金属掺杂后MoSi_(2)N_(4)的带隙类型没有发生改变,均为间接带隙半导体;W掺杂后的杂质能级靠近价带顶,费米能级靠近价带顶,为p型半导体,杂质能级为受主能级;Mn掺杂后的杂质能级靠近导带底,费米能级靠近导带底,为n型半导体;V和Ti掺杂后杂质能级位于费米能级附近,为复合中心;光学性质分析表明,在2 e V~4 e V的能量区间内,W掺杂结构的吸收波长为336 nm,体系发生红移;Mn、V和Ti替位掺杂后的吸收波长分别为320 nm、358 nm和338 nm,且掺杂体系均发生蓝移.
文摘Neuromyelitis optica is an inflammatory demyelinating disease of the central nervous system that differs from multiple sclerosis.Over the past 20 years,the search for biomarke rs for neuromyelitis optica has been ongoing.Here,we used a bibliometric approach to analyze the main research focus in the field of biomarkers for neuromyelitis optica.Research in this area is consistently increasing,with China and the United States leading the way on the number of studies conducted.The Mayo Clinic is a highly reputable institution in the United States,and was identified as the most authoritative institution in this field.Furthermore,Professor Wingerchuk from the Mayo Clinic was the most authoritative expe rt in this field.Keyword analysis revealed that the terms "neuro myelitis optica"(261 times), "multiple sclerosis"(220 times), "neuromyelitis optica spectrum disorder"(132 times), "aquaporin4"(99 times),and "optical neuritis"(87 times) were the most frequently used keywords in literature related to this field.Comprehensive analysis of the classical literature showed that the majority of publications provide conclusive research evidence supporting the use of aquaporin-4-IgG and neuromyelitis optica-IgG to effectively diagnose and differentiate neuromyelitis optica from multiple sclerosis.Furthermore,aquaporin-4-IgG has emerged as a highly specific diagnostic biomarker for neuromyelitis optica spectrum disorder.Myelin oligodendrocyte glycoprotein-IgG is a diagnostic biomarke r for myelin oligodendrocyte glycoprotein antibody-associated disease.Recent biomarkers for neuromyelitis optica in clude cerebrospinal fluid immunological biomarkers such as glial fibrillary acidic protein,serum astrocyte damage biomarkers like FAM19A5,serum albumin,and gammaaminobutyric acid.The latest prospective clinical trials are exploring the potential of these biomarkers.Preliminary results indicate that glial fibrillary acidic protein is emerging as a promising candidate biomarker for neuromyelitis optica spectrum disorder.The ultimate goal of future research is to identify non-invasive biomarkers with high sensitivity,specificity,and safety for the accurate diagnosis of neuro myelitis optica.
基金Funded by the National Natural Science Foundation of China(No.61205062)the Scientific Research Foundation for Doctor of University(No.2019Y02)。
文摘A novel fiber optic sensor based on optical composite oxygen-sensitive film was developed for determination of 2,4-dichlorophenol(DCP).The optical composite oxygen-sensitive film consists of tris(2,2’-bipyridyl)dichloro ruthenium(II)hexahydrate(Ru(bpy)3Cl2)as the fluorescence indicator and iron(III)tetrasulfophthalocyanine(Fe(III)PcTs)as bionic enzyme.A lock-in amplifier was used for detecting the lifetime of the composite oxygen-sensitive film by measuring the phase delay of the sensor head.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions(i e,pH 6.0,25℃,Fe(III)PcTs concentration of 5.0×10^-5 mol/L),the linear detection range,detection limit and response time of the fiber optic sensor are 3.0×10^-7-9.0×10^-5 mol/L,4.8×10^-8 mol/L(S/N=3),and 220 s,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing DCP concentration in practical water samples.
基金support from the Caplin Point Laboratories Limited,Chennai,India
文摘Nickel molybdate(NiMoO4)nanoparticles(NPs)were synthesized by sol-gel method.Utilizing water as solvent providescrystalline nanostructures.These nanocrystals were structurally characterized by X-ray diffraction,energy dispersive X-ray analysis(EDX),and Fourier transform infrared spectra.Compositional stoichiometry was confirmed by EDX technique.The size and shapewere observed by scanning electron microscopy(SEM)and transmission electron microscope(TEM).It was found that the obtainedNPs were pure and single phase crystalline with monoclinic structure.The optical properties were studied by ultraviolet-visiblediffuse reflectance spectroscopy(UV-Vis-DRS)and photoluminescence(PL)measurements at room temperature.The magneticproperties were studied by vibrating sample magnetometer(VSM)and results showed superparamagnetic behavior of the obtainednanoparticles.Photocatalytic activity of NiMoO4was studied.The photocatalytic activity of NiMoO4was enhanced with the additionof TiO2.The catalysts NiMoO4,TiO2and NiMoO4-TiO2nanocomposites(NC)were tested for photocatalytic degradation(PCD)of4-chlorophenol(4-CP).It was found that PCD efficiency of NiMoO4-TiO2NC was higher than that of pure NiMoO4and TiO2.
基金Project supported by the Joint Fund of the National Natural Science Foundation of Chinathe China Academy of Engineering Physics(Grant Nos.U1430117and U1230201)
文摘The electronic structures, the effective masses, and optical properties of spinel CdCr_2S_4 are studied by using the fullpotential linearized augmented planewave method and a modified Becke–Johnson exchange functional within the densityfunctional theory. Most importantly, the effects of the spin–orbit coupling（SOC） on the electronic structures and carrier effective masses are investigated. The calculated band structure shows a direct band gap. The electronic effective mass and the hole effective mass are analytically determined by reproducing the calculated band structures near the BZ center.SOC substantially changes the valence band top and the hole effective masses. In addition, we calculated the corresponding optical properties of the spinel structure CdCr_2S_4. These should be useful to deeply understand spinel CdCr_2S_4 as a ferromagnetic semiconductor for possible semiconductor spintronic applications.
基金supported by the National Natural Science Foundation of China(No.51772159)the Natural Science Foundation of Zhejiang Province(No.LZ17E020001)K.C.Wong Magna Fund in Ningbo University
文摘High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.
基金This study was reviewed and approved by the Institutional Review Board of National Institutes for Quantum Science and Technology,No.07-1064-28.No animals or animal-derived samples or patients or patient-derived samples were included in this study.
文摘BACKGROUND Radionuclides produce Cherenkov radiation(CR),which can potentially activate photosensitizers(PSs)in phototherapy.Several groups have studied Cherenkov energy transfer to PSs using optical imaging;however,cost-effectively identifying whether PSs are excited by radionuclide-derived CR and detecting fluorescence emission from excited PSs remain a challenge.Many laboratories face the need for expensive dedicated equipment.AIM To cost-effectively confirm whether PSs are excited by radionuclide-derived CR and distinguish fluorescence emission from excited PSs.METHODS The absorbance and fluorescence spectra of PSs were measured using a microplate reader and fluorescence spectrometer to examine the photo-physical properties of PSs.To mitigate the need for expensive dedicated equipment and achieve the aim of the study,we developed a method that utilizes a chargecoupled device optical imaging system and appropriate long-pass filters of different wavelengths(manual sequential application of long-pass filters of 515,580,645,700,750,and 800 nm).Tetrakis(4-carboxyphenyl)porphyrin(TCPP)was utilized as a model PS.Different doses of copper-64(^(64)CuCl_(2))(4,2,and 1 mCi)were used as CR-producing radionuclides.Imaging and data acquisition were performed 0.5 h after sample preparation.Differential image analysis was conducted by using ImageJ software(National Institutes of Health)to visually evaluate TCPP fluorescence.RESULTS The maximum absorbance of TCPP was at 390-430 nm,and the emission peak was at 670 nm.The CR and CRinduced TCPP emissions were observed using the optical imaging system and the high-transmittance long-pass filters described above.The emission spectra of TCPP with a peak in the 645-700 nm window were obtained by calculation and subtraction based on the serial signal intensity(total flux)difference between^(64)CuCl_(2)+TCPP and^(64)CuCl_(2).Moreover,the differential fluorescence images of TCPP were obtained by subtracting the^(64)CuCl_(2)image from the^(64)CuCl_(2)+TCPP image.The experimental results considering different^(64)CuCl_(2)doses showed a dosedependent trend.These results demonstrate that a bioluminescence imaging device coupled with different longpass filters and subtraction image processing can confirm the emission spectra and differential fluorescence images of CR-induced TCPP.CONCLUSION This simple method identifies the PS fluorescence emission generated by radionuclide-derived CR and can contribute to accelerating the development of Cherenkov energy transfer imaging and the discovery of new PSs.
基金Supported by the National Natural Science Foundation of China under Grant No 51572053
文摘We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho：GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.05 W, corresponding to a slope efficiency of 74.6%. The ZGP-OPO laser produces 4.2 ns mid-infrared pulses at a pulse repetition rate of 5 kHz. In addition, we obtain 0.8 um of tunable range for the signal wave and 2.1 um of tunable range for the idler wave.
基金Project(50474051) supported by the National Natural Science Foundation of China
文摘The electronic structure and optical properties of novel Na-hP4 high pressure phase at different pressures(260,320,400 and 600 GPa)were investigated by the density functional theory(DFT)with the generalized gradient approximation(GGA)for the exchange and correlation energy.The band structure along the higher symmetry axes in the Brillouin zone,the density of states(DOS) and the partial density of states(PDOS)were presented.The band gap increases and the energy band expands to some extent with the pressure increasing.The dielectric function,reflectivity,energy-loss function,optical absorption coefficient,optical conductivity, refractive index and extinction coefficient were calculated for discussing the optical properties of Na-hP4 high pressure phase at different pressures.
