Background:Human skin is affected by ultraviolet rays on a daily basis,and excessive ultraviolet radiation(UVR)can lead to sunburn erythema,tanning,photoaging,and skin tumors.The combination of Astragali Radix(AR)and ...Background:Human skin is affected by ultraviolet rays on a daily basis,and excessive ultraviolet radiation(UVR)can lead to sunburn erythema,tanning,photoaging,and skin tumors.The combination of Astragali Radix(AR)and Anemarrhenae Rhizoma(AAR)is a common pairing in traditional Chinese medicine(TCM).According to earlier studies,they possess properties capable of alleviating the adverse impacts of UVR on the skin.However,the specific actions and underlying mechanisms require further investigation.The study aims to analyze the efficacy of AR-AAR in preventing UVR-induced skin damage and to clarify the associated molecular mechanisms.Methods:Potential signaling pathways by which AR and AAR may protect against UVR-induced skin damage were identified with network pharmacology,molecular docking techniques and molecular dynamics(MD)simulation.Except the normal group,the back skin of SD rats was exposed to 1.1 mW/cm^(2) UVA combined with 0.1 mW/cm^(2) UVB daily,and the UVR skin damage model was established.Morphological features of skin tissues of different groups were discovered through Hematoxylin and Eosin(HE)staining,Masson staining,Weigert staining.ELISA was utilized to measure the levels of reactive oxygen species(ROS),Interleukin 6(IL-6),Interleukin 1β(IL-1β)and Tumor necrosis factos-α(TNF-α)in skin tissues.RT-PCR and Western blot were employed to quantify the mRNA and protein contents of PI3K,AKT,and MMP-9.Results:Network pharmacology analysis predicts that AR-AAR may improve skin damage induced by UVR through the PI3K/AKT signaling pathway.Histological staining shows that AR-AAR can significantly reduce inflammatory infiltration and fibrosis in damaged skin.Treatment with AR-AAR(2:1)significantly reduced the expression levels of IL-1β,IL-6,TNF-αand ROS in UVR-damaged rat skin.After treatment with AR-AAR(2:1),not only did the relative mRNA expression levels of PI3K and AKT and the protein expression levels of PI3K,AKT,P-PI3K,and P-AKT increase,but the mRNA and protein expression levels of MMP-9 decreased.Conclusion:The study indicate that the AR-AAR combination and its active components may mitigate UVR skin damage by modulating the PI3K/AKT signaling pathway.展开更多
BACKGROUND Empathetic psychological care improves mood and enhances the quality of life in critically ill patients.AIM To study the impact of combining 222-nm ultraviolet(UV)disinfection with empathetic psychological ...BACKGROUND Empathetic psychological care improves mood and enhances the quality of life in critically ill patients.AIM To study the impact of combining 222-nm ultraviolet(UV)disinfection with empathetic psychological care on emotional states,nosocomial infection rates,and quality of life in critically ill patients.METHODS A total of 202 critically ill patients admitted to Beijing Ditan Hospital(December 2023 to May 2024)were randomly assigned to control(Ctrl,n=101)or observation groups(Obs,n=101).The Ctrl group received 222-nm UV disinfection and routine care,while the Obs group received 222-nm UV disinfection with empathetic psychological care.Emotional states[Self-Rating Anxiety Scale(SAS),Self-Rating Depression Scale(SDS)],hospital infection rates,quality of life(36-Item Short Form Health Survey),and patient satisfaction were evaluated.RESULTS At baseline,there were no significant differences in SAS and SDS scores between the groups(P>0.05).Following care,both groups demonstrated reductions in SAS and SDS scores,with the Obs group exhibiting a significantly greater reduction(P<0.05).The Obs group also experienced a significantly lower overall hospital infection rate(P<0.05).Similarly,while baseline 36-Item Short Form Health Survey scores did not differ significantly between the groups(P>0.05),post-care scores improved in both groups,with a greater improvement observed in the Obs group(P<0.05).Additionally,the Obs group reported higher patient satisfaction ratings(P<0.05).CONCLUSION The combination of 222-nm UV disinfection and empathetic psychological care improves emotional states,reduces hospital infection rates,enhances the quality of life,and increases patient satisfaction among critically ill patients.展开更多
During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other pollutants.In this ...During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other pollutants.In this study,the impact of chlorination and UV modification on the physicochemical properties of polystyrene(PS)and polyvinyl chloride(PVC)were investigated,and the adsorption behavior of pefloxacin(PEF)before and after modificationwas examined.The effect of pH,ionic strength,dissolved organicmatter,heavymetal ions and other water environmental conditions on adsorption behavior was revealed.The results showed that PS had a higher adsorption capacity of PEF than PVC,and the modification increased the presence of O-containing functional groups in the MPs,thereby enhancing the adsorption capacity of both materials.Chlorination had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period,leading to better adsorption performance of chlorination.The optimal pH for adsorption was found to be 6,and NaCl,sodium alginate and Cu2+would inhibit adsorption to varying degrees,among which the inhibition caused by pH was the strongest.Chlorination and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by MPs.The main mechanisms of adsorption involved electrostatic interaction and hydrogen bonding.The study clarified the effects of modification on the physicochemical properties of MPs,providing reference for subsequent biotoxicity analysis and environmental protection studies.展开更多
This paper describes what is thought to be the first generation of a continuous wave deep ultraviolet laser at 275 nm by efficient frequency doubling of a blue-diode-pumped Pr:YLF laser at 550 nm.By employing a novel ...This paper describes what is thought to be the first generation of a continuous wave deep ultraviolet laser at 275 nm by efficient frequency doubling of a blue-diode-pumped Pr:YLF laser at 550 nm.By employing a novel fast-axis collimated blue semiconductor laser as the pump source,combined with a folded cavity and innovation coating technology,and utilizing a Brewster-cut BBO crystal for intracavity frequency doubling,TEM00 mode deep UV laser radiation at 275 nm with an output power of 351 mW is obtained.This marks the first report of achieving 275 nm laser generation based on Pr:LiYF4 to date.展开更多
Sulfates are always promising short-wave ultraviolet(UV)nonlinear optical(NLO)candidates,if their birefringence could be greatly improved.Here,in terms of the insufficient birefringence,the unity of heteroleptic tetra...Sulfates are always promising short-wave ultraviolet(UV)nonlinear optical(NLO)candidates,if their birefringence could be greatly improved.Here,in terms of the insufficient birefringence,the unity of heteroleptic tetrahedral groups and triangular ones was proposed and implemented.Thus,a new semiorganic crystal,[C(NH_(2))_(3)]S_(3)O_(6)(G_(2)S_(3)O_(6)),was obtained,which is composed of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]+groups.It exhibits excellent optical properties with a short absorption cutoff edge of 218 nm,a strong NLO response of 1.4×KH_(2)PO_(4),and more especially,a large birefringence of 0.097@546 nm.This birefringence leap makes the G_(2)S_(3)O_(6) crystal achieve a phase-matching behavior under a 532 nm laser.Thus,the synergy of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]~+groups results in excellent optical performances.This finding opens a new horizon for exploring novel UV NLO crystals.展开更多
Amorphous InGaZnO(IGZO)is a potential candidate for integrated circuits based on thin-film transistors(TFTs)owing to its low-temperature processability and high mobility.Amorphous InGaMgO/InGaZnO(IGMO/IGZO)heterojunct...Amorphous InGaZnO(IGZO)is a potential candidate for integrated circuits based on thin-film transistors(TFTs)owing to its low-temperature processability and high mobility.Amorphous InGaMgO/InGaZnO(IGMO/IGZO)heterojunction was deposited and TFTs based on IGMO/IGZO heterojunction were fabricated in this report.The energy band at the IGMO/IGZO heterojunction was characterized,and the potential well at the interface of IGZO is critical to the enhanced ultraviolet detection of the IGMO/IGZO heterojunction.Furthermore,the TFTs based on IGMO/IGZO heterojunction exhibited a high responsivity of 3.8×10^(3) A/W and a large detectivity of 5.2×10^(14) Jones under 350-nm ultraviolet illumination,which will also benefit for fabrication of monolithic ultraviolet sensing chip.展开更多
Wireless ultraviolet (UV) has strong scattering characteristics and can communicate through non-direct vision.When UV signals are transmitted in the atmosphere,they are affected by the absorption and scattering effect...Wireless ultraviolet (UV) has strong scattering characteristics and can communicate through non-direct vision.When UV signals are transmitted in the atmosphere,they are affected by the absorption and scattering effects of atmospheric particles and atmospheric turbulence,resulting in attenuation of UV signal energy and reduced reliability of the communication system.This paper focuses on the channel model of UV non-direct-view single scattering communication,and simulates and analyzes the communication characteristics of UV light in atmospheric turbulence and mixed aerosol environment under horizontal,vertical and oblique range communication scenarios.The results show that at equal relative humidity,the wireless UV non-directive scattering communication performance for vertical communication scenarios is more affected by the mixed aerosol environment and the communication performance is worse.展开更多
Self-powered photoelectrochemical-type(PEC)ultraviolet photodetectors(UV PDs)have been rapidly developed owing to their low-cost fabrication and good photodetection.However,achieving high-performance and selfpowered P...Self-powered photoelectrochemical-type(PEC)ultraviolet photodetectors(UV PDs)have been rapidly developed owing to their low-cost fabrication and good photodetection.However,achieving high-performance and selfpowered PEC UV PDs based on an individual material is still challenging.Therefore,developing more wide bandgap semiconductors for high-performance PEC UV PDs is attractive.Here,we demonstrate that ZnAl-LDH is suitable for self-powered PEC UV PDs with high responsivity and excellent wavelength selectivity for the first time.The responsivity is 29.25 mA/W(254 nm irradiation)and the UV/visible rejection ratio is 1037,surpassing most PEC UV PDs.Furthermore,the PEC UV PDs have fast response,good stability,and underwater optical communication capability.This work offers more chances for the development of high-performance PEC UV PDs and demonstrates the potential application of ZnAl-LDH in underwater optoelectronic devices.展开更多
This study examines diffuse ultraviolet(UV)emissions in the PHOENIX_00 region near galaxy clusters using GALEX deep observations.In the far-UV(FUV)and near-UV(NUV),we detected backgrounds of 125-200 and225-350 photon ...This study examines diffuse ultraviolet(UV)emissions in the PHOENIX_00 region near galaxy clusters using GALEX deep observations.In the far-UV(FUV)and near-UV(NUV),we detected backgrounds of 125-200 and225-350 photon units(PU),with scatters of±16 and±22 PU,respectively.A moderate FUV-NUV correlation and FUV/NUV ratio below unity indicate FUV-dominated emission and little molecular hydrogen fluorescence or hot-line contributions.Dust influences the FUV background more strongly than the NUV,and UV band emissions correlate more strongly at Galactic latitudes|gb|>71°.29.Infrared(IR)color ratios IR_(60)/IR_(100)(≈0.34±0.03)indicate homogeneous large-grain temperatures and depletion of small grains and PAHs,while IR60/IR25 below 3 indicates AGN activity in the region.The non-zero offsets of IR-UV plots 89 PU(FUV)and199 PU(NUV)indicate the region s baseline illumination and extragalactic radiation.Approximately 11%of the FUV offset and 23%of the NUV offset come from extragalactic background light,while the rest comes from dust-scattered starlight.Finally,our research shows that the interstellar radiation field directly affects the UV background,with the strength inversely proportional to local dust content.展开更多
Grapevine(Vitis vinifera L.)is one of the main crops worldwide,and ultraviolet-B(UV-B,280-315 nm)radiation is emerging as a promising technical tool to enhance secondary metabolites that can contribute to the quality ...Grapevine(Vitis vinifera L.)is one of the main crops worldwide,and ultraviolet-B(UV-B,280-315 nm)radiation is emerging as a promising technical tool to enhance secondary metabolites that can contribute to the quality and health-promoting properties of both grapes and the resulting wines.However,few studies have assessed the effectiveness of UV-B supplements under field conditions.Here,we compared the effects of two different field UV-B treatments(a single supplement applied at pre-harvest,and a double supplement applied at both veraison and pre-harvest)on the phenolic composition of Tempranillo grape skins and the resulting wines.The double supplement induced stronger changes than the single supplement,with responses being more pronounced in grape skins than in wines.In skins,UV-B supplements significantly increased flavonols,phenolic acids,and flavanols,consistent with previous reports highlighting flavonols as the most reliable UV-B-responsive compounds in grape skins.In wines,the clearest responses were increases in anthocyanins and color intensity.Overall,UV-B supplements improved grape and wine quality,although skin responses were only partially transmitted to the wines.Moreover,wine responses were more unpredictable than skin responses,likely reflecting not only the UV-B-induced changes in grape skins but also the complex chemical interactions among phenolic compounds(and also with other metabolites)during vinification.Further experimentation,particularly in the long term,is required to optimize the application of UV-B supplements as a viticultural and enological practice.展开更多
[Objectives] To identify Pyrostegia venusta (Ker-Gawler.) Miers by microscope and ultraviolet spectrum. [Methods] The paraffin section, slide section and freehand section were used to make the cross section of the ste...[Objectives] To identify Pyrostegia venusta (Ker-Gawler.) Miers by microscope and ultraviolet spectrum. [Methods] The paraffin section, slide section and freehand section were used to make the cross section of the stem and leaf, and the surface of the leaf and the powder of the root, stem and leaf were made by the conventional method, which were observed under the optical microscope. Ultraviolet-visible spectrum identification was carried out according to a conventional method. [Results] The microscopic identification and ultraviolet-visible absorption characteristics of P. venusta (Ker-Gawler) Miers were described in detail. [Conclusions] This study is expected to provide a reference for the identification of P. venusta(KerGawler)Miers and the establishment of the related quality standard.展开更多
As a new layered semiconductor material,Bi_(2)SeO_(5) has shown potential in the field of ultraviolet electronic devices in recent years because of its unique crystal structure and wide band gap.In this paper,the crys...As a new layered semiconductor material,Bi_(2)SeO_(5) has shown potential in the field of ultraviolet electronic devices in recent years because of its unique crystal structure and wide band gap.In this paper,the crystal structure,electronic structure,and thermodynamic stability of Bi_(2)SeO_(5) are studied based on first-principles calculations.The ultraviolet luminescence property of BiSe defect is predicated from defect property,which provides theoretical basis for experimental design of high-performance Bi2SeO5 photoelectric devices.展开更多
The development of high-performance dual-band photodetectors(PDs)capable of simultaneous deep ultraviolet(DUV)and infrared(IR)detection is critical for advanced optoelectronic applications,particularly in missile warn...The development of high-performance dual-band photodetectors(PDs)capable of simultaneous deep ultraviolet(DUV)and infrared(IR)detection is critical for advanced optoelectronic applications,particularly in missile warning and target identification systems.Conventional UV/IR PDs often suffer from UV(320-400 nm)noise interference and limited responsivity due to the use of narrow-bandgap semiconductors and self-powered operation modes.To address these challenges,high-quality β-Ga_(2)O_(3)thin films were epitaxially grown on c-plane sapphire via metalorganic chemical vapor deposition(MOCVD),exhibiting excellent crystallinity and surface morphology.Unlike conventional heterojunctions(β-Ga_(2)O_(3)/graphene or β-Ga_(2)O_(3)/TMDs),the β-Ga_(2)O_(3)/BP structure leverages BP's tunable bandgap and high carrier mobility while maintaining strong type-Ⅱ band alignment,thereby facilitating efficient charge separation under both UV and IR illumination.We present a high-sensitivity dual-band PD based on a β-Ga_(2)O_(3)/black phosphorus(BP)pn heterojunction.The ultrawide bandgap of β-Ga_(2)O_(3)enables selective detection of DUV light while effectively suppressing interference from long-wave ultraviolet(UVA,320-400 nm),whereas BP provides a layer-dependent infrared(IR)response.Photocurrent analysis reveals distinct carrier transport mechanisms,with electrons dominating under UV illumination and holes contributing predominantly under IR exposure.A systematic investigation of the bias-dependent photoresponse demonstrates that the responsivity increases significantly at higher voltages.Under a 7 V bias,the device exhibits a high responsivity of 4.63×10^(-2)mA/W at 254 nm and 2.35×10^(-3)mA/W at 850 nm.This work not only provides a viable strategy for developing high-performance dual-band PDs but also advances the understanding of heterojunction-based optoelectronic devices for military and sensing applications.展开更多
This review describes the effects of ultraviolet-B （UV-B） radiation on plant growth and development, photosynthesis and photosynthetic pigments and UV-B absorbing compounds. Moreover, plant ecosystem level responses...This review describes the effects of ultraviolet-B （UV-B） radiation on plant growth and development, photosynthesis and photosynthetic pigments and UV-B absorbing compounds. Moreover, plant ecosystem level responses to elevated UV-B radiation and interactions of UV-B radiation with abiotic and biotic factors were also involved. Results collected in this review suggest that approximately two-thirds terrestrial plant species are significantly affected by increase in UV-B radiation, The majority of evidences indicate that elevated UV-B radiation is usually detrimental but there exists tremendous variability in the sensitivity of species to UV-B radiation, and sensitivity also differs among cultivars of the same species.展开更多
Ultraviolet （UV） aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene r...Ultraviolet （UV） aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene rubber （SBR） asphalts with different contents of three anti-UV-aging agents including nano-TiO2, CeO2 and carbon black are performed. Common indices, which include retained penetration after thin film oven tests （TFOT） and softening point, and strategic highway research program （SHRP） indices of aged asphalts are evaluated. Infrared absorption spectral analysis is performed on asphalt specimens with 0. 8% carbon black which have been aged for different aging times （500, 1000 and 1 500 h）. By grey incidence analysis, the optimal contents of anti-UV-aging agents are determined. The results show that TiO2 and CeO2 are not only good UV absorbing or shielding agents, but also strong oxidants. Carbon black is a good anti-UV-aging agent, and its optimal content is about 0. 8% of asphalt weight. UV aging of asphalt mainly occurs in the early stages of aging. The longer the aging time, the more severe the aging of asphalt.展开更多
A promising method to improve the attosecond pulse intensity has been theoretically pre- sented by properly adding an ultraviolet pulse into the orthogonal two-color field. The results show that by properly adding a 1...A promising method to improve the attosecond pulse intensity has been theoretically pre- sented by properly adding an ultraviolet pulse into the orthogonal two-color field. The results show that by properly adding a 125 nm ultraviolet pulse to the orthogonal two-color field, not only the harmonic yield is enhanced by 2 orders of magnitude compared with the original orthogonal two-color field case, but also the single short quantum path, which is selected to contribute to the harmonic spectrum, results in an ultrabroad 152 eV bandwidth. Moreover, by optimizing the laser parameters, we find that the harmonic enhancement is not very sen- sitive to the pulse duration and the polarized angle of the assisted ultraviolet pulse, which is much better for experimental realization. As a result, an isolated pulse with duration of 38 as can be obtained, which is 2 orders of magnitude improvement in comparison with the original two-color orthogonal field case.展开更多
基金supported by the Shaanxi Qinchuang Yuan“scientist+engineer”team construction(No.2023KXJ-080)Shaanxi Chiral Drug Engineering Technology Research Center(Department of Science and Technology of Shaanxi Province.No.[2011]-251).
文摘Background:Human skin is affected by ultraviolet rays on a daily basis,and excessive ultraviolet radiation(UVR)can lead to sunburn erythema,tanning,photoaging,and skin tumors.The combination of Astragali Radix(AR)and Anemarrhenae Rhizoma(AAR)is a common pairing in traditional Chinese medicine(TCM).According to earlier studies,they possess properties capable of alleviating the adverse impacts of UVR on the skin.However,the specific actions and underlying mechanisms require further investigation.The study aims to analyze the efficacy of AR-AAR in preventing UVR-induced skin damage and to clarify the associated molecular mechanisms.Methods:Potential signaling pathways by which AR and AAR may protect against UVR-induced skin damage were identified with network pharmacology,molecular docking techniques and molecular dynamics(MD)simulation.Except the normal group,the back skin of SD rats was exposed to 1.1 mW/cm^(2) UVA combined with 0.1 mW/cm^(2) UVB daily,and the UVR skin damage model was established.Morphological features of skin tissues of different groups were discovered through Hematoxylin and Eosin(HE)staining,Masson staining,Weigert staining.ELISA was utilized to measure the levels of reactive oxygen species(ROS),Interleukin 6(IL-6),Interleukin 1β(IL-1β)and Tumor necrosis factos-α(TNF-α)in skin tissues.RT-PCR and Western blot were employed to quantify the mRNA and protein contents of PI3K,AKT,and MMP-9.Results:Network pharmacology analysis predicts that AR-AAR may improve skin damage induced by UVR through the PI3K/AKT signaling pathway.Histological staining shows that AR-AAR can significantly reduce inflammatory infiltration and fibrosis in damaged skin.Treatment with AR-AAR(2:1)significantly reduced the expression levels of IL-1β,IL-6,TNF-αand ROS in UVR-damaged rat skin.After treatment with AR-AAR(2:1),not only did the relative mRNA expression levels of PI3K and AKT and the protein expression levels of PI3K,AKT,P-PI3K,and P-AKT increase,but the mRNA and protein expression levels of MMP-9 decreased.Conclusion:The study indicate that the AR-AAR combination and its active components may mitigate UVR skin damage by modulating the PI3K/AKT signaling pathway.
基金Supported by Beijing Ditan Hospital Affiliated to Capital Medical University“Sailing Plan”,No.DTQH-202405.
文摘BACKGROUND Empathetic psychological care improves mood and enhances the quality of life in critically ill patients.AIM To study the impact of combining 222-nm ultraviolet(UV)disinfection with empathetic psychological care on emotional states,nosocomial infection rates,and quality of life in critically ill patients.METHODS A total of 202 critically ill patients admitted to Beijing Ditan Hospital(December 2023 to May 2024)were randomly assigned to control(Ctrl,n=101)or observation groups(Obs,n=101).The Ctrl group received 222-nm UV disinfection and routine care,while the Obs group received 222-nm UV disinfection with empathetic psychological care.Emotional states[Self-Rating Anxiety Scale(SAS),Self-Rating Depression Scale(SDS)],hospital infection rates,quality of life(36-Item Short Form Health Survey),and patient satisfaction were evaluated.RESULTS At baseline,there were no significant differences in SAS and SDS scores between the groups(P>0.05).Following care,both groups demonstrated reductions in SAS and SDS scores,with the Obs group exhibiting a significantly greater reduction(P<0.05).The Obs group also experienced a significantly lower overall hospital infection rate(P<0.05).Similarly,while baseline 36-Item Short Form Health Survey scores did not differ significantly between the groups(P>0.05),post-care scores improved in both groups,with a greater improvement observed in the Obs group(P<0.05).Additionally,the Obs group reported higher patient satisfaction ratings(P<0.05).CONCLUSION The combination of 222-nm UV disinfection and empathetic psychological care improves emotional states,reduces hospital infection rates,enhances the quality of life,and increases patient satisfaction among critically ill patients.
基金supported by the Shanxi Scholarship Council of China(No.2023-054)the Applied Basic Research Project of Shanxi Province,China(No.20210302123121)the National Natural Science Foundation of China(No.52170045).
文摘During thewater treatment process,chlorination and ultraviolet(UV)sterilization can modify microplastics(MPs)and alter their physicochemical properties,causing various changes between MPs and other pollutants.In this study,the impact of chlorination and UV modification on the physicochemical properties of polystyrene(PS)and polyvinyl chloride(PVC)were investigated,and the adsorption behavior of pefloxacin(PEF)before and after modificationwas examined.The effect of pH,ionic strength,dissolved organicmatter,heavymetal ions and other water environmental conditions on adsorption behavior was revealed.The results showed that PS had a higher adsorption capacity of PEF than PVC,and the modification increased the presence of O-containing functional groups in the MPs,thereby enhancing the adsorption capacity of both materials.Chlorination had a more significant impact on the physicochemical properties of MPs compared to UV irradiation within the same time period,leading to better adsorption performance of chlorination.The optimal pH for adsorption was found to be 6,and NaCl,sodium alginate and Cu2+would inhibit adsorption to varying degrees,among which the inhibition caused by pH was the strongest.Chlorination and UV modification would weaken the inhibitory effect of environmental factors on the adsorption of PEF by MPs.The main mechanisms of adsorption involved electrostatic interaction and hydrogen bonding.The study clarified the effects of modification on the physicochemical properties of MPs,providing reference for subsequent biotoxicity analysis and environmental protection studies.
文摘This paper describes what is thought to be the first generation of a continuous wave deep ultraviolet laser at 275 nm by efficient frequency doubling of a blue-diode-pumped Pr:YLF laser at 550 nm.By employing a novel fast-axis collimated blue semiconductor laser as the pump source,combined with a folded cavity and innovation coating technology,and utilizing a Brewster-cut BBO crystal for intracavity frequency doubling,TEM00 mode deep UV laser radiation at 275 nm with an output power of 351 mW is obtained.This marks the first report of achieving 275 nm laser generation based on Pr:LiYF4 to date.
基金supported by the National Natural Science Foundation of China(Nos.52172009 and 12275274)the Science and Technology Project of Fujian Province(Nos.2021J01519 and 2021H0043)the Instrument Developing Project of Chinese Academy of Sciences(No.YJKYYQ20210033)。
文摘Sulfates are always promising short-wave ultraviolet(UV)nonlinear optical(NLO)candidates,if their birefringence could be greatly improved.Here,in terms of the insufficient birefringence,the unity of heteroleptic tetrahedral groups and triangular ones was proposed and implemented.Thus,a new semiorganic crystal,[C(NH_(2))_(3)]S_(3)O_(6)(G_(2)S_(3)O_(6)),was obtained,which is composed of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]+groups.It exhibits excellent optical properties with a short absorption cutoff edge of 218 nm,a strong NLO response of 1.4×KH_(2)PO_(4),and more especially,a large birefringence of 0.097@546 nm.This birefringence leap makes the G_(2)S_(3)O_(6) crystal achieve a phase-matching behavior under a 532 nm laser.Thus,the synergy of[S_(3)O_(6)]^(2-)and[C(NH_(2))_(3)]~+groups results in excellent optical performances.This finding opens a new horizon for exploring novel UV NLO crystals.
基金supported by the Regional Innovation and Development Joint Fund of the National Nature Science Foundation of China(Grant No.U21A2071).
文摘Amorphous InGaZnO(IGZO)is a potential candidate for integrated circuits based on thin-film transistors(TFTs)owing to its low-temperature processability and high mobility.Amorphous InGaMgO/InGaZnO(IGMO/IGZO)heterojunction was deposited and TFTs based on IGMO/IGZO heterojunction were fabricated in this report.The energy band at the IGMO/IGZO heterojunction was characterized,and the potential well at the interface of IGZO is critical to the enhanced ultraviolet detection of the IGMO/IGZO heterojunction.Furthermore,the TFTs based on IGMO/IGZO heterojunction exhibited a high responsivity of 3.8×10^(3) A/W and a large detectivity of 5.2×10^(14) Jones under 350-nm ultraviolet illumination,which will also benefit for fabrication of monolithic ultraviolet sensing chip.
基金supported by the National Natural Science Foundation of China (No.61971345)the Shaanxi Province Key R&D Program General Project (No.2021GY044)the Open Fund for Artificial Intelligence Key Laboratory of Sichuan Province (No.2022RYY01)。
文摘Wireless ultraviolet (UV) has strong scattering characteristics and can communicate through non-direct vision.When UV signals are transmitted in the atmosphere,they are affected by the absorption and scattering effects of atmospheric particles and atmospheric turbulence,resulting in attenuation of UV signal energy and reduced reliability of the communication system.This paper focuses on the channel model of UV non-direct-view single scattering communication,and simulates and analyzes the communication characteristics of UV light in atmospheric turbulence and mixed aerosol environment under horizontal,vertical and oblique range communication scenarios.The results show that at equal relative humidity,the wireless UV non-directive scattering communication performance for vertical communication scenarios is more affected by the mixed aerosol environment and the communication performance is worse.
基金support from the Heilongjiang Provincial Natural Science Foundation of China(No.YQ2020E003).
文摘Self-powered photoelectrochemical-type(PEC)ultraviolet photodetectors(UV PDs)have been rapidly developed owing to their low-cost fabrication and good photodetection.However,achieving high-performance and selfpowered PEC UV PDs based on an individual material is still challenging.Therefore,developing more wide bandgap semiconductors for high-performance PEC UV PDs is attractive.Here,we demonstrate that ZnAl-LDH is suitable for self-powered PEC UV PDs with high responsivity and excellent wavelength selectivity for the first time.The responsivity is 29.25 mA/W(254 nm irradiation)and the UV/visible rejection ratio is 1037,surpassing most PEC UV PDs.Furthermore,the PEC UV PDs have fast response,good stability,and underwater optical communication capability.This work offers more chances for the development of high-performance PEC UV PDs and demonstrates the potential application of ZnAl-LDH in underwater optoelectronic devices.
文摘This study examines diffuse ultraviolet(UV)emissions in the PHOENIX_00 region near galaxy clusters using GALEX deep observations.In the far-UV(FUV)and near-UV(NUV),we detected backgrounds of 125-200 and225-350 photon units(PU),with scatters of±16 and±22 PU,respectively.A moderate FUV-NUV correlation and FUV/NUV ratio below unity indicate FUV-dominated emission and little molecular hydrogen fluorescence or hot-line contributions.Dust influences the FUV background more strongly than the NUV,and UV band emissions correlate more strongly at Galactic latitudes|gb|>71°.29.Infrared(IR)color ratios IR_(60)/IR_(100)(≈0.34±0.03)indicate homogeneous large-grain temperatures and depletion of small grains and PAHs,while IR60/IR25 below 3 indicates AGN activity in the region.The non-zero offsets of IR-UV plots 89 PU(FUV)and199 PU(NUV)indicate the region s baseline illumination and extragalactic radiation.Approximately 11%of the FUV offset and 23%of the NUV offset come from extragalactic background light,while the rest comes from dust-scattered starlight.Finally,our research shows that the interstellar radiation field directly affects the UV background,with the strength inversely proportional to local dust content.
基金the project PID2023-150695NB-I00,funded by MCIU/AEI/10.13039/501100011033/FEDER,UEAdditional funding from the Agencia de Desarrollo Economico de La Rioja(ADER,Government of La Rioja)through the Project S-UV-STAINABLE Rioja(2022-I-IDI-00064)is also acknowledged.
文摘Grapevine(Vitis vinifera L.)is one of the main crops worldwide,and ultraviolet-B(UV-B,280-315 nm)radiation is emerging as a promising technical tool to enhance secondary metabolites that can contribute to the quality and health-promoting properties of both grapes and the resulting wines.However,few studies have assessed the effectiveness of UV-B supplements under field conditions.Here,we compared the effects of two different field UV-B treatments(a single supplement applied at pre-harvest,and a double supplement applied at both veraison and pre-harvest)on the phenolic composition of Tempranillo grape skins and the resulting wines.The double supplement induced stronger changes than the single supplement,with responses being more pronounced in grape skins than in wines.In skins,UV-B supplements significantly increased flavonols,phenolic acids,and flavanols,consistent with previous reports highlighting flavonols as the most reliable UV-B-responsive compounds in grape skins.In wines,the clearest responses were increases in anthocyanins and color intensity.Overall,UV-B supplements improved grape and wine quality,although skin responses were only partially transmitted to the wines.Moreover,wine responses were more unpredictable than skin responses,likely reflecting not only the UV-B-induced changes in grape skins but also the complex chemical interactions among phenolic compounds(and also with other metabolites)during vinification.Further experimentation,particularly in the long term,is required to optimize the application of UV-B supplements as a viticultural and enological practice.
基金Supported by Scientific Research Program of Guangxi University of Chinese Medicine(P200246).
文摘[Objectives] To identify Pyrostegia venusta (Ker-Gawler.) Miers by microscope and ultraviolet spectrum. [Methods] The paraffin section, slide section and freehand section were used to make the cross section of the stem and leaf, and the surface of the leaf and the powder of the root, stem and leaf were made by the conventional method, which were observed under the optical microscope. Ultraviolet-visible spectrum identification was carried out according to a conventional method. [Results] The microscopic identification and ultraviolet-visible absorption characteristics of P. venusta (Ker-Gawler) Miers were described in detail. [Conclusions] This study is expected to provide a reference for the identification of P. venusta(KerGawler)Miers and the establishment of the related quality standard.
基金supported by the National Natural Science Foundation of China under Grant No.12404093the China Postdoctoral Science Foundation under Grant No.2021M702915.
文摘As a new layered semiconductor material,Bi_(2)SeO_(5) has shown potential in the field of ultraviolet electronic devices in recent years because of its unique crystal structure and wide band gap.In this paper,the crystal structure,electronic structure,and thermodynamic stability of Bi_(2)SeO_(5) are studied based on first-principles calculations.The ultraviolet luminescence property of BiSe defect is predicated from defect property,which provides theoretical basis for experimental design of high-performance Bi2SeO5 photoelectric devices.
基金supported by the National Natural Science Foundation of China(Grant No.U22A2073)。
文摘The development of high-performance dual-band photodetectors(PDs)capable of simultaneous deep ultraviolet(DUV)and infrared(IR)detection is critical for advanced optoelectronic applications,particularly in missile warning and target identification systems.Conventional UV/IR PDs often suffer from UV(320-400 nm)noise interference and limited responsivity due to the use of narrow-bandgap semiconductors and self-powered operation modes.To address these challenges,high-quality β-Ga_(2)O_(3)thin films were epitaxially grown on c-plane sapphire via metalorganic chemical vapor deposition(MOCVD),exhibiting excellent crystallinity and surface morphology.Unlike conventional heterojunctions(β-Ga_(2)O_(3)/graphene or β-Ga_(2)O_(3)/TMDs),the β-Ga_(2)O_(3)/BP structure leverages BP's tunable bandgap and high carrier mobility while maintaining strong type-Ⅱ band alignment,thereby facilitating efficient charge separation under both UV and IR illumination.We present a high-sensitivity dual-band PD based on a β-Ga_(2)O_(3)/black phosphorus(BP)pn heterojunction.The ultrawide bandgap of β-Ga_(2)O_(3)enables selective detection of DUV light while effectively suppressing interference from long-wave ultraviolet(UVA,320-400 nm),whereas BP provides a layer-dependent infrared(IR)response.Photocurrent analysis reveals distinct carrier transport mechanisms,with electrons dominating under UV illumination and holes contributing predominantly under IR exposure.A systematic investigation of the bias-dependent photoresponse demonstrates that the responsivity increases significantly at higher voltages.Under a 7 V bias,the device exhibits a high responsivity of 4.63×10^(-2)mA/W at 254 nm and 2.35×10^(-3)mA/W at 850 nm.This work not only provides a viable strategy for developing high-performance dual-band PDs but also advances the understanding of heterojunction-based optoelectronic devices for military and sensing applications.
基金supported by the National NaturalScience Foundation of China (30700085)the National Basic Re-search Program of China (2009CB421101)
文摘This review describes the effects of ultraviolet-B （UV-B） radiation on plant growth and development, photosynthesis and photosynthetic pigments and UV-B absorbing compounds. Moreover, plant ecosystem level responses to elevated UV-B radiation and interactions of UV-B radiation with abiotic and biotic factors were also involved. Results collected in this review suggest that approximately two-thirds terrestrial plant species are significantly affected by increase in UV-B radiation, The majority of evidences indicate that elevated UV-B radiation is usually detrimental but there exists tremendous variability in the sensitivity of species to UV-B radiation, and sensitivity also differs among cultivars of the same species.
文摘Ultraviolet （UV） aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene rubber （SBR） asphalts with different contents of three anti-UV-aging agents including nano-TiO2, CeO2 and carbon black are performed. Common indices, which include retained penetration after thin film oven tests （TFOT） and softening point, and strategic highway research program （SHRP） indices of aged asphalts are evaluated. Infrared absorption spectral analysis is performed on asphalt specimens with 0. 8% carbon black which have been aged for different aging times （500, 1000 and 1 500 h）. By grey incidence analysis, the optimal contents of anti-UV-aging agents are determined. The results show that TiO2 and CeO2 are not only good UV absorbing or shielding agents, but also strong oxidants. Carbon black is a good anti-UV-aging agent, and its optimal content is about 0. 8% of asphalt weight. UV aging of asphalt mainly occurs in the early stages of aging. The longer the aging time, the more severe the aging of asphalt.
文摘A promising method to improve the attosecond pulse intensity has been theoretically pre- sented by properly adding an ultraviolet pulse into the orthogonal two-color field. The results show that by properly adding a 125 nm ultraviolet pulse to the orthogonal two-color field, not only the harmonic yield is enhanced by 2 orders of magnitude compared with the original orthogonal two-color field case, but also the single short quantum path, which is selected to contribute to the harmonic spectrum, results in an ultrabroad 152 eV bandwidth. Moreover, by optimizing the laser parameters, we find that the harmonic enhancement is not very sen- sitive to the pulse duration and the polarized angle of the assisted ultraviolet pulse, which is much better for experimental realization. As a result, an isolated pulse with duration of 38 as can be obtained, which is 2 orders of magnitude improvement in comparison with the original two-color orthogonal field case.
