不同强度UVA对银杏杂交子代生理生化的影响

【目的】探究不同强度UVA对银杏杂交子代可溶性糖、可溶性蛋白、抗氧化酶活性、黄酮代谢相关酶活性以及总黄酮含量的影响,得出提高银杏总黄酮含量的最佳光质处理,为银杏的栽培与选育提供理论依据。【方法】以二年生银杏杂交子代实生苗为试验材料,设置不同强度的紫外光UVA(395~405 nm)处理,在相同强度的白光(300μmol·m^(2)·s^(-1))下分别添加2、4、6根UVA紫外灯,紫外光强为20μmol·m^(-2)·s^(-1)(UVA-2)、40μmol·m^(-2)·s^(-1)(UVA-4)、60μmol·m^(-2)·s^(-1)(UVA-6),以白光(300μmol·m^(2)·s^(-1))做为对照(CK)。【结果】不同强度UVA处理对银杏杂交子代各项生理指标都存在显著影响,随着UVA强度的增加,银杏杂交子代可溶性糖和可溶性蛋白含量呈现逐渐上升的趋势。金叶银杏SOD、POD、PAL、C4H、4CL酶活性随着UVA强度的增加呈现先增加后减小的趋势,绿叶银杏SOD酶活性随着UVA强度的增加而增加,而POD、PAL、C4H、4CL酶活性呈现先增后减的趋势。银杏杂交子代总黄酮含量、DPPH和ABTS自由基清除率呈现先增后减的趋势,在UVA-4处理20 d时达到最大,绿叶银杏总黄酮含量最高,为28.65 mg·g^(-1),比CK处理高56.3%。除了SOD和POD外,金叶银杏其他生理指标都低于绿叶银杏。相关性结果表明,银杏各生理指标间都呈现极显著正相关。多因素方差分析发现叶色、处理时间以及UVA强度对银杏各项生理指标都存在极显著影响,并且UVA强度和处理时间两者的交互效应对抗氧化酶活性、黄酮代谢相关酶活性、黄酮含量以及DPPH、ABTS自由基清除率存在极显著影响。【结论】不同强度UVA处理对银杏杂交子代各指标存都在显著影响,40μmol·m^(-2)·s^(-1)的UVA处理20 d绿叶银杏总黄酮含量最高。

UVA紫外光在植物工厂生菜生产中的适量试用研究

本文研究了在植物工厂中使用不同剂量的UVA紫外光对生菜的生长、品质和贮藏的影响。以白光为基础增加不同剂量的UVA紫外光模拟太阳光,制成了植物工厂生菜光照专用的LED灯管。试验选用了意大利生菜作为测试品种,控制植物工厂内的生长条件和采后贮藏条件,测试UVA紫外光对生菜生长、品质和贮藏的影响;结果表明,UVA紫外光照射对生菜生生长、品质和贮藏具有剂量饱和效应,只有适量的UVA紫外光照射可以促进生菜的生长,改善生菜品质,延晚贮藏的叶色褐变以及养分流失。这为植物工厂的光能高效利用提供理论依据,为生菜的优质高效生产和贮藏提供技术支持。

UVA增强型棒状TiO_(2)复合材料的制备及紫外屏蔽性能研究

在低温水解条件下制备了一种长波紫外线(UVA)增强型棒状金红石TiO_(2),将Al(OH)_(3)均匀包覆在TiO_(2)表面,然后使用月桂酰赖氨酸(LL)对TiO_(2)/Al(OH)_(3)进行表面改性,最后在TiO_(2)/Al(OH)_(3)/LL表面包覆一层天然防晒剂白藜芦醇(RES),得到TiO_(2)/Al(OH)_(3)/LL/RES(TALR)复合材料。采用X射线衍射仪、傅里叶变换红外光谱仪、透射电子显微镜、扫描电子显微镜和热重分析仪等对样品的结构、形貌及热稳定性进行表征。结果表明:Al(OH)_(3)以非晶态形式均匀包覆在棒状金红石TiO_(2)表面,适宜包覆量为10%(质量分数);棒状TiO_(2)在中波紫外线(UVB)范围具有优异的紫外屏蔽能力,对UVA仍有令人满意的吸收效果;改性剂LL的最佳包覆量为12%,RES的最佳包覆量为15%(均为质量分数)。抗氧化实验及防晒指数测试结果表明,TALR复合材料具有良好的自由基清除能力和优异的紫外屏蔽效果。

240 nm AlGaN-based deep ultraviolet micro-LEDs:size effect versus edge effect

240 nm AlGaN-based micro-LEDs with different sizes are designed and fabricated.Then,the external quantum efficiency(EQE)and light extraction efficiency(LEE)are systematically investigated by comparing size and edge effects.Here,it is revealed that the peak optical output power increases by 81.83%with the size shrinking from 50.0 to 25.0μm.Thereinto,the LEE increases by 26.21%and the LEE enhancement mainly comes from the sidewall light extraction.Most notably,transversemagnetic(TM)mode light intensifies faster as the size shrinks due to the tilted mesa side-wall and Al reflector design.However,when it turns to 12.5μm sized micro-LEDs,the output power is lower than 25.0μm sized ones.The underlying mechanism is that even though protected by SiO2 passivation,the edge effect which leads to current leakage and Shockley-Read-Hall(SRH)recombination deteriorates rapidly with the size further shrinking.Moreover,the ratio of the p-contact area to mesa area is much lower,which deteriorates the p-type current spreading at the mesa edge.These findings show a role of thumb for the design of high efficiency micro-LEDs with wavelength below 250 nm,which will pave the way for wide applications of deep ultraviolet(DUV)micro-LEDs.

Ultraviolet‑Irradiated All‑Organic Nanocomposites with Polymer Dots for High‑Temperature Capacitive Energy Storage

Polymer dielectrics capable of operating efficiently at high electric fields and elevated temperatures are urgently demanded by next-generation electronics and electrical power systems.While inorganic fillers have been extensively utilized to improved high-temperature capacitive performance of dielectric polymers,the presence of thermodynamically incompatible organic and inorganic components may lead to concern about the long-term stability and also complicate film processing.Herein,zero-dimensional polymer dots with high electron affinity are introduced into photoactive allyl-containing poly(aryl ether sulfone)to form the all-organic polymer composites for hightemperature capacitive energy storage.Upon ultraviolet irradiation,the crosslinked polymer composites with polymer dots are efficient in suppressing electrical conduction at high electric fields and elevated temperatures,which significantly reduces the high-field energy loss of the composites at 200℃.Accordingly,the ultraviolet-irradiated composite film exhibits a discharged energy density of 4.2 J cm^(−3)at 200℃.Along with outstanding cyclic stability of capacitive performance at 200℃,this work provides a promising class of dielectric materials for robust high-performance all-organic dielectric nanocomposites.

High-speed performance self-powered short wave ultraviolet radiation detectors based onκ(ε)-Ga_(2)O_(3)

High-speed solar-blind short wavelength ultraviolet radiation detectors based onκ(ε)-Ga_(2)O_(3)layers with Pt contacts were demonstrated and their properties were studied in detail.Theκ(ε)-Ga_(2)O_(3)layers were deposited by the halide vapor phase epitaxy on patterned GaN templates with sapphire substrates.The spectral dependencies of the photoelectric properties of struc-tures were analyzed in the wavelength interval 200-370 nm.The maximum photo to dark current ratio,responsivity,detectiv-ity and external quantum efficiency of structures were determined as:180.86 arb.un.,3.57 A/W,1.78×10^(12) Hz^(0.5)∙cm·W^(-1) and 2193.6%,respectively,at a wavelength of 200 nm and an applied voltage of 1 V.The enhancement of the photoresponse was caused by the decrease in the Schottky barrier at the Pt/κ(ε)-Ga_(2)O_(3)interface under ultraviolet exposure.The detectors demon-strated could functionalize in self-powered mode due to built-in electric field at the Pt/κ(ε)-Ga_(2)O_(3)interface.The responsivity and external quantum efficiency of the structures at a wavelength of 254 nm and zero applied voltage were 0.9 mA/W and 0.46%,respectively.The rise and decay times in self-powered mode did not exceed 100 ms.

Effect of Ultraviolet Radiation on Hsp70 Protein Expression in HaCaT Cells

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

Low-Voltage IGZO Field-Effect Ultraviolet Photodiode

In the era of Internet of Things(Io Ts),an energy-efficient ultraviolet(UV)photodetector(PD)is highly desirable considering the massive usage scenarios such as environmental sterilization,fire alarm and corona discharge monitoring.So far,common self-powered UV PDs are mainly based on metal-semiconductor heterostructures or p–n heterojunctions,where the limited intrinsic built-in electric field restricts further enhancement of the photoresponsivity.In this work,an extremely low-voltage field-effect UV PD is proposed using a gatedrain shorted amorphous IGZO(a-IGZO)thin film transistor(TFT)architecture.A combined investigation of the experimental measurements and technology computer-aided design(TCAD)simulations suggests that the reverse current(ⅠR)of field-effect diode(FED)is highly related with the threshold voltage(Vth)of the parental TFT,implying an enhancement-mode TFT is preferable to fabricate the field-effect UV PD with low dark current.Driven by a low bias of-0.1 V,decent UV response has been realized including large UV/visible(R_(300)/R_(550))rejection ratio(1.9×10^(3)),low dark current(1.15×10^(-12)A)as well as high photo-to-dark current ratio(PDCR,~10^(3))and responsivity(1.89 A/W).This field-effect photodiode provides a new platform to construct UV PDs with well-balanced photoresponse performance at a low bias,which is attractive for designs of large-scale smart sensor networks with high energy efficiency.

Ultraviolet Photodetector based on Sr_(2)Nb_(3)O_(10) Perovskite Nanosheets

Liquid-phase exfoliation was employed to synthesize Sr_(2)Nb_(3)O_(10) perovskite nanosheets with thicknesses down to 1.76 nm.Transmission electron microscopy(TEM),atomic force microscope(AFM),X-ray photoelectron spectrometer(XPS),and other characterization techniques were used to evaluate the atomic structure and chemical composition of the exfoliated nanosheets.A UV photodetector based on individual Sr_(2)Nb_(3)O_(10) nanosheets was prepared to demonstrate the application of an ultraviolet(UV) photodetector.The UV photodetector exhibited outstanding photocurrent and responsivity with a responsivity of 3×10^(5) A·W^(-1) at 5 V bias under 280 nm illumination,a photocurrent of 60 nA,and an on/off ratio of 3×10^(2).

Wavelength calibration and spectral analysis of vacuum ultraviolet spectroscopy in EAST

A vacuum ultraviolet(VUV)spectroscopy with a focal length of 1 m has been engineered specifically for observing edge impurity emissions in Experimental Advanced Superconducting Tokamak(EAST).In this study,wavelength calibration for the VUV spectroscopy is achieved utilizing a zinc lamp.The grating angle and charge-coupled device(CCD)position are carefully calibrated for different wavelength positions.The wavelength calibration of the VUV spectroscopy is crucial for improving the accuracy of impurity spectral data,and is required to identify more impurity spectral lines for impurity transport research.Impurity spectra of EAST plasmas have also been obtained in the wavelength range of 50–300 nm with relatively high spectral resolution.It is found that the impurity emissions in the edge region are still dominated by low-Z impurities,such as carbon,oxygen,and nitrogen,albeit with the application of fulltungsten divertors on the EAST tokamak.

Effect of combination of ultraviolet radiation and biocide on fungal-induced corrosion of high-strength 7075 aluminum alloy

The effect of ultraviolet(UV)radiation and biocide benzalkonium chloride(BKC)on fungal-induced corrosion of AA7075 induced by Aspergillus terreus(A.terreus)was deeply studied using analysis of biological activity,surface analysis,and electrochemical measurements.Results demonstrated that the planktonic and sessile spore concentrations decline by more than two orders of magnitude when UV radiation and BKC are combinedly used compared with the control.UV radiation can inhibit the biological activity of A.terreus and influence the stability of passive film of AA7075.Except for direct disinfection,the physical adsorption of BKC on the specimen can effectively inhibit the attachment of A.terreus.The combination of UV radiation and BKC can much more effectively inhibit the corrosion of AA,especially pitting corrosion,due to their synergistic effect.The combined application of UV radiation and BKC can be a good method to effectively inhibit fungal-induced corrosion.

Nitric oxide removal from flue gas coupled with the Fe^(Ⅱ)EDTA regeneration by ultraviolet irradiation

During wet complexation denitrification of flue gas,Fe^(Ⅱ)EDTA regeneration,also known as reducing Fe^(Ⅱ)EDTA and Fe^(Ⅱ)EDTA-nitric oxide(NO)to Fe^(Ⅱ)EDTA,is crucial.In this paper,ultraviolet(UV)light was used for the first time to reduce Fe^(Ⅱ)EDTA-NO.The experimental result demonstrated that Fe^(Ⅱ)EDTA-NO reduction rate increased with UV power increasing,elevated temperature,and initial Fe^(Ⅱ)EDTA-NO concentration decreasing.Fe^(Ⅱ)EDTA-NO reduction rate increased first and then decreased as pH value increased(2.0-10.0).Fe^(Ⅱ)EDTA-NO reduction with UV irradiation presented a first order reaction with respect to Fe^(Ⅱ)EDTA-NO.Compared with other Fe^(Ⅱ)EDTA regeneration methods,Fe^(Ⅱ)EDTA regeneration with UV show more superiority through comprehensive consideration of regeneration rate and procedure.Subsequently,NO absorption experiment by Fe^(Ⅱ)EDTA solution with UV irradiation confirmed that UV can significantly promote the NO removal performance of Fe^(Ⅱ)EDTA.Appropriate oxygen concentration(3%(vol))and acidic environment(pH=4)was favorable for NO removal.With UV power increasing as well as temperature decreasing,NO removal efficiency rose.In addition,the mechanism research indicates that NO from flue gas is mostly converted to NO_(2)-,NO_(3)-,NH_(4)^(+),N_(2),and N_(2)O with Fe^(Ⅱ)EDTA absorption liquid with UV irradiation.UV strengthens NO removal in Fe^(Ⅱ)EDTA absorption liquid by forming a synergistic effect of oxidation-reduction-complexation.Finally,compared with NO removal methods with Fe^(Ⅱ)EDTA,Fe^(Ⅱ)EDTA combined UV system shows prominent technology advantage in terms of economy and secondary pollution.

Optimization of extreme ultraviolet vortex beam based on high harmonic generation

In high harmonic generation(HHG),Laguerre–Gaussian(LG) beams are used to generate extreme ultraviolet(XUV)vortices with well-defined orbital angular momentum(OAM),which have potential applications in fields such as microscopy and spectroscopy.An experimental study on the HHG driven by vortex and Gaussian beams is conducted in this work.It is found that the intensity of vortex harmonics is positively correlated with the laser energy and gas pressure.The structure and intensity distribution of the vortex harmonics exhibit significant dependence on the relative position between the gas jet and the laser focus.The ring-like structures observed in the vortex harmonics,and the interference of quantum paths provide an explanation for the distinct structural characteristics.Moreover,by adjusting the relative position between the jet and laser focus,it is possible to discern the contributions from different quantum paths.The optimization of the HH vortex field is applicable to the XUV,which opens up a new way for exploiting the potential in optical spin or manipulating electrons by using the photon with tunable orbital angular momentum.

Optimizing UVA and UVC synergy for effective control of harmful cyanobacterial blooms

Harmful cyanobacterial blooms(HCBs)pose a global ecological threat.Ultraviolet C(UVC)irradiation at 254 nm is a promising method for controlling cyanobacterial proliferation,but the growth suppression is temporary.Resuscitation remains a challenge with UVC application,necessitating alternative strategies for lethal effects.Here,we show synergistic inhibition of Microcystis aeruginosa using ultraviolet A(UVA)pre-irradiation before UVC.We find that low-dosage UVA pre-irradiation(1.5 J cm^(−2))combined with UVC(0.085 J cm^(−2))reduces 85%more cell densities compared to UVC alone(0.085 J cm^(−2))and triggers mazEF-mediated regulated cell death(RCD),which led to cell lysis,while high-dosage UVA pre-irradiations(7.5 and 14.7 J cm^(−2))increase cell densities by 75-155%.Our oxygen evolution tests and transcriptomic analysis indicate that UVA pre-irradiation damages photosystem I(PSI)and,when combined with UVC-induced PSII damage,synergistically inhibits photosynthesis.However,higher UVA dosages activate the SOS response,facilitating the repair of UVC-induced DNA damage.This study highlights the impact of UVA pre-irradiation on UVC suppression of cyanobacteria and proposes a practical strategy for improved HCBs control.

Summary of a Life in Observational Ultraviolet/Optical Astronomy

I reminisce on my early life in Section 1;on my education in Sections 2 and 3;on the years at Princeton as a research astronomer in Section 4;on the years on the faculty at Chicago in Section 5;on research on Diffuse Interstellar Bands(DIBs) in Section 6;on construction of the 3.5 m telescope at Apache Point Observatory(APO)in Section 7;on work on the Sloan Digital Sky Survey(SDSS) in Section 8;on work in public education in Chicago in Section 9;and on my travels in Section 10. My main science research is of an observational nature,concerning Galactic and intergalactic interstellar gas. Highlights for me included my work on the orbiting telescope Copernicus, including the discovery of interstellar deuterium;early observations of absorption associated with fivetimes ionized oxygen;and discoveries concerning the phases of gas in the local interstellar medium, based on previously unobservable interstellar UV spectral lines. With other instruments and collaborations, I extended interstellar UV studies to the intergalactic cool gas using quasi-stellar object QSO absorption lines redshifted to the optical part of the spectrum;provided a better definition of the emission and morphological character of the source of absorption lines in QSO spectra;and pursued the identification of the unidentified DIBs. For several of these topics, extensive collaborations with many scientists were essential over many years. The conclusions developed slowly, as I moved from being a graduate student at Chicago, to a research scientist position at Princeton and then to a faculty position at Chicago. At each stage of life, I was exposed to new technologies adaptable to my science and to subsequent projects. From high school days, I encountered several management opportunities which were formative. I have been extremely fortunate both in scientific mentors I had and in experimental opportunities I encountered.

Research on the Performance of Non-Line-of-Sight Ultraviolet Communication in Rain and Fog Environment

Wireless ultraviolet communication is a new type of communication mode. It refers to the transmission of information through the scattering of ultraviolet light by atmospheric particles and aerosol particles. The scattering characteristics can enable the wireless ultraviolet communication system to transmit ultraviolet light signals in a non-line-of-sight manner, which overcomes the weakness that other free space optical communications must work in a line-of-sight manner. Based on the basic theory of scattering and absorption in atmospheric optics, taking the ultraviolet light with a wavelength of 266 nm as an example, this paper introduces the classical model of non-line-of-sight single-scattering coplanarity based on the ellipsoid coordinate system. The model is used to simulate and analyze the relationship between the geometric parameters such as transmission distance, transceiver elevation angle and transceiver half-angle and the received optical power per unit area. The performance of non-line-of-sight ultraviolet communication system in rain and fog environment is discussed respectively. The results show that the transmission quality of non-line-of-sight ultraviolet atmospheric propagation is greatly affected by the communication distance. As the distance increases, the received light power per unit area gradually decreases. In addition, increasing the emission elevation angle, the receiving elevation angle and the receiving half angle is an important way to improve the system performance.

UVA补光时间对凡纳滨对虾肌肉主要营养成分影响研究

紫外光A波段(Ultraviolet A,UVA)是自然光的重要组成部分,具有一定的生态功能。本研究选取450尾体重为(9.56±0.10)g的凡纳滨对虾(Penaeus vannamei)以光周期为12L︰12D的全光谱LED灯[光强(1.00±0.02)W/m^(2)]作为背景光源,在不同UVA[光强(1.00±0.02)W/m2]补光时间(0 h,T_(0 h);2 h,T_(2 h);4 h,T_(4 h);8 h,T_(8 h);12 h,T_(12 h))下进行为期28 d的养殖实验。结果显示,在不同UVA补光时长下,对虾肌肉中水分和粗灰分含量无显著差异,T2 h和T4 h组的粗脂肪含量显著增加,T2 h组的粗蛋白显著高于T4 h组外的其他组(P<0.05),T8 h和T12 h组的粗脂肪显著低于其他各组(P<0.05),但两组间差异不显著;T2 h和T4 h组氨基酸总量、必需氨基酸含量和赖氨酸含量均显著高于其他组(P<0.05);凡纳滨对虾饱和脂肪酸(SFA)含量为27.85%~40.70%,单不饱和脂肪酸(MUFA)含量为10.63%~16.31%,多不饱和脂肪酸(PUFA)含量为38.81%~49.61%,其在T2 h和T4 h组显著高于其他各组(P<0.05),且在两组间无显著差异。综上所述,2~4 h的UVA补光时间能够改善凡纳滨对虾肌肉的营养成分。

查耳酮衍生物接枝改性的聚硅氧烷UVA滤光剂

制备了查耳酮衍生物(E)-3-(4-烯丙氧基)苯基-1-苯基丙-2-烯-1-酮(Blank-Cha),(E)-3-(4-烯丙氧基)苯基-1-(4-羟基苯基)丙-2-烯-1-酮(Oxhydryl-Cha)和(E)-3-(4-烯丙氧基)苯基-1-(4-甲氧基苯基)丙-2-烯-1-酮(Methoxy-Cha)。再通过硅氢加成反应将Methoxy-Cha接枝到含氢硅油链上,制备了聚硅氧烷UVA滤光剂(WPUF)。采用NMR、LC-MS及FTIR鉴定产物化学结构,通过UV吸收光谱测试了WPUF的性能,考察了不同取代基对查耳酮衍生物的UV吸收性能和细胞毒性的影响。结果表明,查耳酮衍生物和WPUF已成功制备。查耳酮衍生物摩尔吸光系数>10000 L/(mol·cm),Methoxy-Cha的细胞毒性最低;避光6个月和90℃加热12 h后WPUF的化学结构无变化,模拟阳光照射240 min后UVA吸收能力仅损失30.46%,且WPUF在质量浓度≤250 mg/L下未表现出细胞毒性。体外皮肤穿透实验显示,WPUF角质层平均渗透深度为11μm。体外测定WPUF的防晒指数为36.21,与商用防晒剂相当。

Enhanced Extreme Ultraviolet Free Induction Decay Emission Assisted by Attosecond Pulses

We demonstrate the extreme ultraviolet free induction decay emission that can be significantly enhanced by employing isolated attosecond pulses.The near infrared pulses are applied to excite the neon atoms into Rydberg states coherently,and isolated attosecond pulses are used to manipulate populations of the Rydberg states and the subsequent free induction decay process.The time resolved experimental measurement of dependence of the resonance emission yield would help to understand the buildup dynamics of population of excited states.The enhancement assisted by attosecond pulses can serve as a mechanism to develop high-flux extreme ultraviolet light sources.

Recent developments in deep-ultraviolet sterilization of human respiratory RNA viruses

Deep-ultraviolet(DUV)sterilization technology using DUV-LEDs has attracted considerable attention owing to its portability,eco-friendliness,high potency,and broad-spectrum sterilization.This study compiles the developments of recent DUV sterilization research.Recent works have investigated DUV sterilization from the perspective of device improvement and principle investigation:one employed a novel epitaxial structure to optimize the performance and fabrication cost of DUV-LEDs and realized potent virus disinfection effects for various respiratory RNA viruses,and another work explained the disinfection phenomenon of SARS-CoV-2 and its variants(Delta and Omicron)in a cryogenic environment.These studies have contributed significantly to the development of DUV sterilization.