Determination of Total Lignanoids in Tangjiangshenkang Granules by Two-Wavelength Ultraviolet Spectrophotometry

[Objectives] To establish a determination method for the content of total lignanoids in Tangjiangshenkang granules. [Methods] Two-wavelength ultraviolet spectrophotometry (TWBS) was used to scan arctiin control solution, chlorogenic acid control solution and Tangjiangshenkang granule test solution in the range of 200-400 nm. In the ultraviolet scanning diagram of arctiin reference solution, the maximum absorption wavelength of 280 nm was determined as the determination wavelength λ 1, the detection wavelength in the ultraviolet scanning diagram of chlorogenic acid reference solution ( λ 1=280 nm) was determined, and 350 nm was the reference wavelength λ 2;the content of total lignosides in Tangjiangshenkang granules was determined with arctiin as the reference substance. [Results] The precision, accuracy, and durability of this method were fine. The concentration of arctiin was linearly correlated with the absorbance difference in the range of 0.007 95-0.071 55 mg/mL ( r =0. 999 9). The average recovery of arctiin was 100.8%, and the RSD value was 1.04% ( n =6). Calculated as arctiin, three batches of Tangjiangshenkang granules contain no less than 20% of total lignosides. [Conclusions] The method has the advantages of simple operation, good accuracy, precision and reliable stability. It can be used as the content determination and quality control method of total lignosides in Tangjiangshenkang granules.

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.

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.

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.

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.

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.

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.

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.

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.

ULTRAVIOLET SPECTROPHOTOMETRY OF MULTI-COMPONENT MIXTURES USING ARTIFICIAL NEURAL NETWORKS

Three—layer back—propagation neural networks were used for processing the information provided by the ultraviolet spectra of five—component mixtures, affecting the simultaneous determination of the components with satisfactory results.

Realization of high-efficiency AlGaN deep ultraviolet light-emitting diodes with polarization-induced doping of the p-AlGaN hole injection layer

We investigate the polarization-induced doping in the gradient variation of Al composition in the pAl_(0.75)Ga_(0.25)N/Al_xGa_(1-x)N hole injection layer(HIL)for deep ultraviolet light-emitting diodes(DUV-LEDs)with an ultrathin p-GaN(4 nm)ohmic contact layer capable of emitting 277 nm.The experimental results show that the external quantum efficiency(EQE)and wall plug efficiency(WPE)of the structure graded from 0.75 to 0.55 in the HIL reach 5.49%and 5.04%,which are improved significantly by 182%and 209%,respectively,compared with the structure graded from 0.75 to 0.45,exhibiting a tremendous improvement.Both theoretical speculations and simulation results support that the larger the difference between 0.75 and x in the HIL,the higher the hole concentration that should be induced;thus,the DUV-LED has a higher internal quantum efficiency(IQE).Meanwhile,as the value of x decreases,the absorption of the DUV light emitted from the active region by the HIL is enhanced,reducing the light extraction efficiency(LEE).The IQE and LEE together affect the EQE performance of DUV-LEDs.To trade off the contradiction between the enhanced IQE and decreased LEE caused by the decrease in Al composition,the Al composition in the HIL was optimized through theoretical calculations and experiments.

High performance solar-blind deep ultraviolet photodetectors viaβ-phase(In_(0.09)Ga_(0.91))_(2)O_(3)single crystalline film

We successfully fabricate a high performanceβ-phase(In_(0.09)Ga_(0.91))_(2)O_(3)single-crystalline film deep ultraviolet(DUV)solar-blind photodetector.The 2-inches high crystalline quality film is hetero-grown on the sapphire substrates using the plasma-assisted molecular beam epitaxy(PA-MBE).The smooth InGaO single crystalline film is used to construct the solar-blind DUV detector,which utilized an interdigitated Ti/Au electrode with a metal-semiconductor-metal structure.The device exhibits a low dark current of 40 pA(0 V),while its UV photon responsivity exceeds 450 A/W(50 V)at the peak wavelength of 232 nm with illumination intensity of 0.21 m W/cm^(2)and the UV/VIS rejection ratio(R232 nm/R380 nm)exceeds 4×10^(4).Furthermore,the devices demonstrate ultrafast transient characteristics for DUV signals,with fast-rising and fast-falling times of 80 ns and 420 ns,respectively.This excellent temporal dynamic behavior can be attributed to indium doping can adjust the electronic structure of Ga_(2)O_(3)alloys to enhance the performance of InGaO solar-blind detectors.Additionally,a two-dimensional DUV scanning image is captured using the InGaO photodetector as a sensor in an imaging system.Our results pave the way for future applications of two-dimensional array DUV photodetectors based on the large-scale InGaO heteroepitaxially grown alloy wide bandgap semiconductor films.

Rapid accuracy determining DNA purity and concentration in heavy oils by spectrophotometry methods

DNA analysis is the core of biotechnology applied in petroleum resources and engineering. Traditionally accurate determination of DNA purity and concentration by spectrometer is the first and critical step for downstream molecular biology research. In this study, three different spectrophotometry methods, BPM, NDTT and NPMTTZ were compared for their performance in determining DNA concentration and purity in 32 oil samples, and molecule methods like quantitative real-time PCR (qPCR) and high-throughput sequence were also performed to help assess the accuracy of the three methods in determining DNA concentration and purity. For ordinary heavy oil (OHO), extra heavy oil (EHO) and super heavy oil (SHO), the characteristics of high viscosity (η), density (ρ) and resin plus asphaltene content will affect the DNA extraction and UV determination. The DNA concentration was decreased as density increased: OHO (11.46 ± 18.34 ng/μL), EHO (6.68 ± 9.67 ng/μL) and SHO (6.20 ± 7.83 ng/μL), and the DNA purity was on the reverse: OHO (1.31 ± 0.27), EHO (1.54 ± 0.20), and SHO (1.83 ± 0.32). The results suggest that spectrophotometry such as BPM and NPMTTZ are qualitatively favorite methods as the quick non-consumable methods in determining DNA concentration and purity of medium oil and heavy oil.

A laser-produced plasma source based on thin-film Gd targets for next-generation extreme ultraviolet lithography

We have studied laser-produced plasma based on mass-limited thin-film Gd targets for beyond the current extreme ultraviolet(EUV)light source of 13.5 nm wavelength based on tin.The influences of the laser intensity on the emission spectra centered around 6.7 nm from thin-film Gd targets were first investigated.It is found that the conversion efficiency of the produced plasma is saturated when the laser intensity goes beyond 2×10^(11)W cm^(-2).We have systematically compared the emission spectra of the laser-produced plasma with the changes in the thicknesses of the thin-film Gd targets.It is proved that a minimum-mass target with a thickness of 400 nm is sufficient to provide the maximum conversion efficiency,which also implies that this thickness is the ablation depth for the targets.These findings should be helpful in the exploration of next-generation EUV sources,as the thin-film Gd targets will reduce the debris during the plasma generation process compared with the bulk targets.

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.

X-Ray and Ultraviolet Flares on AT Microscopii Observed by AstroSat

We present observations of the active M-dwarf binary AT Mic(dM4.5e+dM4.5e)obtained with the orbital observatory Astro Sat.During 20 ks of observations,in the far-ultraviolet(130-180 nm)and soft X-ray(0.3-7 keV)spectral ranges,we detected both quiescent emission and at least five flares on different components of the binary.The X-ray flares were typically longer than and delayed(by 5-6 minutes)with respect to their ultraviolet counterparts,in agreement with the Neupert effect.Using X-ray spectral fits,we estimated the parameters of the emitting plasma.The results indicate the presence of a hot multi-thermal corona with average temperatures in the range of~7-15 MK and emission measure of~(2.9-4.5)×10^(52)cm^(-3);both the temperature and the emission measure increased during the flares.The estimated abundance of heavy elements in the corona of AT Mic is considerably lower than at the Sun(~0.18-0.34 of the solar photospheric value);the coronal abundance increased during the flares due to chromospheric evaporation.The detected flares had the energies of~10^(31)-10^(32)erg;the energy-duration relations indicate the presence of magnetic fields stronger than in typical solar flares.

Retrieval and Regional Distribution Analysis of Ammonia,Sulfur Dioxide and Nitrogen Dioxide in the Urban Environment Using Ultraviolet DOAS Algorithm

Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.

Middle and near ultraviolet spectrograph of the Scientific Experimental system in Near SpacE(SENSE)

The Scientific Experimental system in Near SpacE(SENSE)consists of different types of instruments that will be installed on a balloon-based platform to characterize near-space environmental parameters.As one of the main scientific payloads,the middle and near ultraviolet spectrograph(MN-UVS)will provide full spectra coverage from middle ultraviolet(MUV,200−300 nm)to near ultraviolet(NUV,300−400 nm)with a spectral resolution of 2 nm.Its primary mission is to acquire data regarding the UV radiation background of the upper atmosphere.The MN-UVS is made up of six primary components:a fore-optical module,an imaging grating module,a UV intensified focal plane module,a titanium alloy frame,a spectrometer control module,and a data processing module.This paper presents in detail the engineering design of each functional unit of the MN-UVS,as well as the instrument’s radiometric calibration,wavelength calibration,impact test,and low-pressure discharge test.Furthermore,we are able to report ground test and flight test results of high quality,showing that the MN-UVS has a promising future in upcoming near-space applications.