Quantification of six bioactive compounds in Zhenqi Fuzheng preparation by high-performance liquid chromatography coupled with diode array detector and evaporative light scattering detector

A simple and accurate high-performance liquid chromatography（HPLC）coupled with diode array detector（DAD）and evaporative light scattering detector（ELSD）was established for the determination of six bioactive compounds in Zhenqi Fuzheng preparation（ZFP）.The monitoring wavelengths were 254,275 and 328 nm.Under the optimum conditions,good separation was achieved,and the assay was fully validated in respect of precision,repeatability and accuracy.The proposed method was successfully applied to quantify the six ingredients in 31 batches of ZFP samples and evaluate the variation by hierarchical cluster analysis（HCA）,which demonstrated significant variations on the content of these compounds in the samples from different manufacturers with different preparation procedures.The developed HPLC method can be used as a valid analytical method to evaluate the intrinsic quality of this preparation.

Determination of AF and AFG in Red Ginseng by High Performance Liquid Chromatography with Evaporative Light Scattering Detector (HPLC-ELSD)

[Objective]The paper was to establish a method for determining AF and AFG in red ginseng.[Method]A new simple,rapid and sensitive method for simultaneous determination of two amadori compounds,arginyl-fructose(AF)and arginyl-fructosyl-glucose(AFG),in extracts of three kinds of ginseng preparations was developed and validated using high performance liquid chromatography with evaporative light scattering detector(HPLC-ELSD).Two target analytes were efficiently separated by Prevail CTM18 column(4.6 mm×250 mm,5μm)at the flow rate of 0.8 mL/min within 15 min of single chromatographic run.[Result]Under optimized conditions,the detection limits were 0.015 and 0.02 mg/mL for AF and AFG,respectively.Calibration curves of peak area for two analytes were linear over three orders of magnitude with the correlation coefficients greater than 0.999.The average recoveries,precision,reproducibility and stability for two analytes(AF and AFG)were 99.5% and 100.9%,0.43% and 0.47%,0.46% and 0.43%,0.41% and 0.49%,respectively.[Conclusion]This method was successfully applied for quantifying AF and AFG in red ginseng and the method was efficient,sensitive and accurate.

HPLC Analysis of Egg Yolk Phosphatidylcholine by Evaporative Light Scattering Detector

Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).

Determination of azithromycin in raw materials and pharmaceutical formulations by HPLC coupled with an evaporative light scattering detector

A simple high-performance liquid chromatography(HPLC)method coupled with an evaporative light scattering detector(ELSD)was developed for the determination of azithromycin in raw materials and pharmaceutical formulations(injections,capsules and tablets)without any pretreatment or derivatization step.Azithromycin,degradation products and formulation ingredients were separated efficiently by using the mobile phase consisted of ammonium acetate(0.05 M,pH 8.0)and acetonitrile(60:40,v/v)in an isocratic mode at 0.8 ml/min flow rate.Parameters of ELSD were 60
C for evaporation temperature and 50 psi for pressure of carrier gas(air).A logarithmic calibration curve was obtained from 50.93 to 509.30 mg/ml(r¼0.9996)for azithromycin,with the limit of detection(LOD)of 6.75 mg/ml(S/n¼3)and the limit of quantification of 22.50 mg/ml(S/n¼10).The developed method was validated and applied with satisfactory accuracy and precision for the determination of azithromycin in raw materials and pharmaceutical formulations(recovery 99e102%,RSD<1.2%,n¼3).No significant difference(t-test)was found between the results of the developed HPLCeELSD method and the HPLCeUV or microbiological method.

Technique of Position Sensitive Detector with Alternating Light Source

The signal processing circuits of position sensitive detector(PSD) with alternating light source are presented.The measuring device of PSD with alternating light source can effectively eliminate the interference made by light noise signal.

Using monochromatic light to measure attenuation length of liquid scintillator solvent LAB

Linear alkylbenzene(LAB) will be used as solvent for the liquid scintillator in the central detector of Jiangmen Underground Neutrino Observatory. The sheer size of the detector imposes significant challenges and the necessity to further improve the optical transparency of high-quality LAB. In order to study high optical transparencies, we continuously improve our measurement setup and use monochromatic light to measure the attenuation lengths of LAB samples. Moreover, the effects of organic impurities on LAB samples are studied to understand their interaction mechanisms and further improve the optical transparency of LAB.

Simulation study on performance optimization of a prototype scintillation detector for the GRANDProto35 experiment

As a proposed detector,the giant radio array for neutrino detection(GRAND)is primarily designed to discover and study the origin of ultra-high-energy cosmic rays,with ultra-high-energy neutrinos presenting the main method for detecting ultra-high-energy cosmic rays and their sources.The main principle is to detect radio emissions generated by ultra-high-energy neutrinos interacting with the atmosphere as they travel.GRAND is the largest neutrino detection array to be built in China.GRANDProto35,as the first stage of the GRAND experiment,is a coincidence array composed of radio antennas and a scintillation detector,the latter of which,as a traditional detector,is used to perform cross-validation with radio detection,thus verifying the radio detection efficiency and enabling study of the background exclusion method.This study focused on the implementation of the optimization simulation and experimental testing of the performance of the prototype scintillation detector used in GRANDProto35.A package based on GEANT4 was used to simulate the details of the scintillation detector,including the optical properties of its materials,the height of the light guide box,and position inhomogeneity.The surface of the scintillator and the reflective materials used in the detector was optimized,and the influence of light guide heights and position inhomogeneity on the energy and time resolutions of the detector was studied.According to the simulation study,the number of scintillator photoelectrons increased when changing from the polished surface to the ground surface,with the appropriate design height for the light guide box being 50 cm and the appropriate design area for the scintillator being 0.5 m^(2).The performance of the detector was tested in detail through a coincidence experiment,and the test results showed that the number of photoelectrons collected in the detector was$84 with a time resolution of~1 ns,indicating good performance.The simulation results were consistent with those obtained from the tests,which also verified the reliability of the simulation software.These studies provided a full understanding of the performance of the scintillation detector and guidance for the subsequent operation and analysis of the GRANDProto35 experimental array.

CsI-bowl:an ancillary detector for exit channel selection inγ-ray spectroscopy experiments

A particle detector array designed for light-charged particles, known as the CsI-bowl, was built for exit channel selection for in-beam γ-ray spectroscopy experiments. This device is composed of 64 CsI(Tl) detectors, organized in a structure reminiscent of a tea-bowl. High quantum efficiency photodiodes, characterized by their minimal mass, were employed to collect scintillation light. Its design, construction, particle identification resolution, and its effectiveness in relation to exit channel selection are described in this paper. In source tests, the optimal figure of merit for the identification of α-particles and γ-rays using the charge comparison method was found to be 3.3 and 12.1 for CsI detectors coupled to photodiodes and avalanche photodiodes, respectively. The CsI-bowl demonstrated effectiveness in identifying particles, specifically the emission of protons and α-particles in the58Ni(19F, xpyn) fusion–evaporation reaction, thereby enabling the selection of the desired exit channels.

Two annular CsI(Tl) detector arrays for the charged particle telescopes

In this study,we constructed two annular detector arrays comprising 24 wedge-shaped CsI(Tl) crystals,and tested them using anαsource and radioactive beams of ^(14-16) Con a CD_2 target.We compared the properties of a CsI(Tl) crystal encapsulated with various reflectors,revealing that using the 80-μm-thick ESR film to pack the CsI(Tl) crystal yielded the largest light output with the smallest non-uniformity in light output (ΔLO).For the 24 CsI(Tl) detectors with the 80-μm-thick ESR films,the average energy resolution improved as the average light output increased;however,it deteriorated as theΔLO value increased.To form two annular Si-CsI(Tl) telescopes for identifying the light-charged particles,theΔLO value and energy resolution of each CsI(Tl) detector were maintained under 20%and 7.7%,respectively.These telescopes were tested for the first time in a direct nuclear reaction experiment using ^(14-16) C+d.The results demonstrated that the Z=1 and Z=2 charged particles were adequately discriminated by the telescopes using the standardΔE-E method.

High-speed visible light communication based on micro-LED:A technology with wide applications in next generation communication

The evolution of next-generation cellular networks is aimed at creating faster,more reliable solutions.Both the next-generation 6G network and the metaverse require high transmission speeds.Visible light communication(VLC)is deemed an important ancillary technology to wireless communication.It has shown potential for a wide range of applications in next-generation communication.Micro light-emitting diodes(μLEDs)are ideal light sources for high-speed VLC,owing to their high modulation bandwidths.In this review,an overview ofμLEDs for VLC is presented.Methods to improve the modulation bandwidth are discussed in terms of epitaxy optimization,crystal orientation,and active region structure.Moreover,electroluminescent white LEDs,photoluminescent white LEDs based on phosphor or quantum-dot color conversion,andμLED-based detectors for VLC are introduced.Finally,the latest high-speed VLC applications and the application prospects of VLC in 6G are introduced,including underwater VLC and artificial intelligence-based VLC systems.

The intensity detection of single-photon detectors based on photon counting probability density statistics

Single-photon detectors possess the ultra-high sensitivity, but they cannot directly respond to signal intensity. Conven- tional methods adopt sampling gates with fixed width and count the triggered number of sampling gates, which is capable of obtaining photon counting probability to estimate the echo signal intensity. In this paper, we not only count the number of triggered sampling gates, but also record the triggered time position of photon counting pulses. The photon counting probability density distribution is obtained through the statistics of a series of the triggered time positions. Then Minimum Variance Unbiased Estimation （MVUE） method is used to estimate the echo signal intensity. Compared with conventional methods, this method can improve the estimation accuracy of echo signal intensity due to the acquisition of more detected information. Finally, a proof-of-principle laboratory system is established. The estimation accuracy of echo signal intensity is discussed and a high accuracy intensity image is acquired under low-light level environments.

Organic bulk heterojunction enabled with nanocapsules of hydrate vanadium pentaoxide layer for high responsivity self-powered photodetector

This article demonstrates the fabrication of organic-based devices using a low-cost solution-processable technique.A blended heterojunction of chlorine substituted 2D-conjugated polymer PBDB-T-2Cl,and PC71BM supported nanocapsules hy-drate vanadium penta oxides(HVO)as hole transport layer(HTL)based photodetector fabricated on an ITO coated glass sub-strate under ambient condition.The device forms an excellent organic junction diode with a good rectification ratio of~200.The device has also shown excellent photodetection properties under photoconductive mode(at reverse bias)and zero bias for green light wavelength.A very high responsivity of~6500 mA/W and high external quantum efficiency(EQE)of 1400%have been reported in the article.The proposed organic photodetector exhibits an excellent response and recovery time of~30 and~40 ms,respectively.

高效液相色谱-蒸发光散射法测定油莎豆块茎发育过程中的水溶性糖

基于高效液相色谱-蒸发光散射法(HPLC-ELSD)建立油莎豆块茎发育过程中水溶性糖(果糖、葡萄糖、蔗糖)含量的检测方法。以乙腈∶水(体积比75∶25)为流动相,流速为1.0 mL/min,并将蒸发光散射检测器条件优化为氮气压力206.8 kPa、漂移管温度65℃。结果表明:3种水溶性糖在0.10~20.0 mg/mL质量浓度范围内线性关系良好(r>0.999),检出限为0.04~0.10 g/100 g,回收率为96.0%~100.2%,相对标准偏差(RSD)为1.00%~7.32%(n=6)。在油莎豆块茎发育过程中,其果糖含量为0.376~0.692 g/100 g,葡萄糖含量为0.366~0.787 g/100 g,两者呈显著正相关(P<0.01);蔗糖含量为5.49~24.2 g/100 g,呈先降低后总体升高的趋势。所建方法灵敏度高、重现性好,适用于油莎豆块茎发育过程中水溶性糖的测定。

可见光载荷对云海背景下某型隐身飞机探测能力研究

为研究可见光探测器对某型隐身飞机探测能力,首先建立可见光波段云-海-大气耦合的多向吸收-散射模型;再通过对飞机蒙皮和尾焰几何截面在不同太阳入射角和卫星观测角度下的反射特性建模分析,计算到达探测器焦平面的目标以及背景的光谱能量分布,从而得到在给定光照条件下探测器极限信噪比和极限探测距离.最后模拟的仿真成像结果验证了分析模型的正确性和结论的可信度.分析结果表明,以云-海为地物观测背景时,云层的上行反射特性对飞机可探测性的影响最为显著;当太阳入射角小于60°时,飞机蒙皮的表面双向反射率(BRDF)明显高于海平面;太阳入射角大于60°时,云层和海平面对阳光的反射占据主导地位.

HPLC-ELSD同时测定腺梗豨莶草中6个二萜成分的含量

为了研究腺梗豨莶草中6个二萜成分(对映海松烯型二萜:奇任醇、Hythiemoside B和豨莶精醇;对映贝壳杉烷型二萜:对映-17,18-二羟基-贝壳杉烷-19-羧酸、对映-16β,17-二羟基-贝壳杉烷-19-羧酸和对映-16α氢-贝壳杉烷-17,19-二羧酸)的含量,本试验建立了高效液相色谱法-蒸发光散射检测器(HPLC-ELSD)同时测定二萜类化合物含量。样品粉碎过筛加甲醇和乙酸乙酯回流提取,蒸发减压除去溶剂,甲醇溶解,0.45μm滤膜滤过,取续滤液进行测定。色谱条件:色谱柱为Waters Symmetry Shield^(TM)RP18柱(250 mm×4.6 mm,5μm),流动相为0.3%甲酸水溶液-乙腈(v/v),梯度洗脱,流速为1.0 mL/min。蒸发光散射检测器漂移管温度为103℃,雾化气流速为3.0 L/min。应用该方法测定腺梗豨莶草样品不同部位中6个二萜类化合物的含量,同时比较叶、枝、茎中对映海松烯型二萜、对映贝壳杉型二萜和总二萜含量的差异。结果显示,6个二萜成分在其线性范围内线性关系良好(r≥0.9992);日内和日间精密度相对标准偏差(RSD)均小于3.5%;回收率介于96.5%~101.5%,RSD均小于2.3%;腺梗豨莶草不同部位(叶、枝、茎)的二萜类化合物含量差异较大。结果表明,本试验所建立的HPLC-ELSD方法简便、准确、重复性好,为腺梗豨莶草药材全面的质量评价和临床应用中最佳药用部位的选择提供了参考。

芪归养血颗粒质控标准研究

目的研究建立芪归养血颗粒质控的标准。方法采用薄层色谱法(TLC)对黄芪、淫羊藿、菟丝子进行定性鉴别,通过超高效液相色谱-蒸发光散射检测器(UPLC-ELSD)测定制剂中黄芪甲苷含量:色谱柱:Acclaim RSLC 120 C_(18)(100 mm×2.1 mm,2.2µm),ELSD,流动相为乙腈-水(32∶68),流速为0.4 ml/min;柱温30℃;进样体积为1μl。结果TLC能特异性鉴别黄芪、淫羊藿、菟丝子。黄芪甲苷的注射量与峰面积具有良好的线性关系,线性范围为0.0826~0.8260µg,r=0.9996;平均回收率为99.19%,相对标准偏差(RSD)为0.74%。结论采用TLC法和UPLC-ELSD检测对芪归养血颗粒分别进行了定性鉴别和定量分析,所建立的方法专属性强,结果准确,可作为芪归养血颗粒的质控方法进行应用。

基于超快激光调制的纳秒脉冲X射线发射源

面向基础科学与空间应用研究领域对小型化超快脉冲X射线发射源的需求,设计并研制了基于激光调制光源与光电阴极X射线管的超快脉冲X射线发生器,解决了传统X射线调制发射装置重复频率低、时间稳定性差、脉冲特性差等应用难题.本文主要开展了脉冲X射线发生器的超快调制控制模块研究,并利用基于预调制的激光控制光源实现了高时间精度、高时间稳定度的超快时变光子信号以及纳秒脉冲X射线产生.理论方面,建立了脉冲X射线发生器时间响应模型,分析了出射脉冲X射线的时域时间特性.实验方面,搭建了基于超快闪烁体探测器的脉冲X射线时间特性实验测试系统,测试了激光控制光源及脉冲X射线发射源的时间特性参数.实验结果表明脉冲X射线发生器可同时实现高重频(12.5 MHz)、超快脉冲(4 ns)、高时间稳定度(400 ps)特性,且与所建立的理论模型高度符合.相比于传统X射线调制方案,脉冲时间参数指标得到了大幅提升、应用场景获得了极大拓展,本项研究有望为实现超高时间稳定性、超快脉冲X射线发射源提供新思路.

闪烁晶体几何形状、表面处理和单双面读出对伽马射线探测器光收集的影响

能量分辨率是闪烁体探测器的一个重要性能指标,特别是对于伽马能谱仪等伽马射线探测和识别领域。光收集是影响闪烁体探测器能量分辨率的一个重要因素,本工作利用Geant4工具包对闪烁体探测器中的光子传输进行了模拟,模拟了CsI(Na)晶体形状、表面处理和探测器的读出方式等对伽马射线探测器的光收集效率和光收集均匀性的影响。模拟结果表明,通过对圆柱、圆台、长方体和正方体等晶体形状的结果进行对比,圆台具有较高光收集效率和光收集均匀性;晶体表面研磨后具有更好的光收集特性;双面读出方式比单面读出方式的光收集性更高,能够提高10%~20%。为验证该模型的可靠性,搭建了实验平台进行实验验证工作,实验结果与蒙特卡罗模拟结果在2%范围内一致,该研究工作为优化伽马射线探测器以提高能量分辨率提供了关键设计依据。

超临界流体-蒸发光散射法测定常见油脂类药用辅料皂化后的脂肪酸组成及其在油脂鉴别中的应用

脂肪酸是油脂类药用辅料的重要组成成分,可直接反映油脂类药用辅料及制剂的质量和安全性。本研究利用超临界流体色谱-蒸发光散射检测器,建立了同时测定肉豆蔻酸、棕榈酸、硬脂酸、花生酸、二十二烷酸和木蜡酸6种脂肪酸的分析方法。为避免脂肪酸与酯相互转化而造成的脂肪酸种类与含量测定偏差,本方法采取先皂化后测定的方式,并系统优化了实验条件,实现了6种脂肪酸的定量分析。在优化的实验条件下,6种脂肪酸可在12 min内实现高效分离,并且在各自的质量浓度范围内线性关系良好,检出限和定量限分别为5~10 mg/L和10~25 mg/L,加标回收率为80.93%~111.66%。本文所建立方法灵敏,高效,重复性和稳定性好,满足油脂类药用辅料中脂肪酸的分析要求,并成功应用于5种常见油脂类药用辅料(玉米油、大豆油、椰子油、橄榄油、花生油)中6种脂肪酸的含量测定;同时结合主成分分析方法,实现了对不同油脂类药用辅料的准确判别,为油脂类药用辅料的快速鉴别和掺伪分析提供了有价值的参考。

高性能宽谱上转换成像发光二极管性能优化

高性能宽谱上转换成像器件在医疗、食品安全、无损检测和国家安全等领域中发挥着重要作用,但现有半导体上转换器件因探测范围窄、上转换效率低而受到限制。为实现更宽谱和高效的上转换,本文通过优化LED结构,显著提升了棘轮上转换器件的性能。改进后的LED发光效率提升了2个数量级,μA量级的驱动电流下即可开启发光,发光光谱更接近规则洛伦兹线型,器件整体面发光均匀性也显著提升。研究明确了性能优化原则,并为未来上转换器件的改进提供了参考方向。