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 compo...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.展开更多
[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 ...[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.展开更多
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,...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.展开更多
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 formulatio...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 60C 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.展开更多
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...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.展开更多
The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays a...The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.展开更多
Regional sustainable development necessitates a holistic understanding of spatiotemporal variations in ecosystem carbon storage(ECS),particularly in ecologically sensitive areas with arid and semi-arid climate.In this...Regional sustainable development necessitates a holistic understanding of spatiotemporal variations in ecosystem carbon storage(ECS),particularly in ecologically sensitive areas with arid and semi-arid climate.In this study,we calculated the ECS in the Ningxia Section of Yellow River Basin,China from 1985 to 2020 using the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model based on land use data.We further predicted the spatial distribution of ECS in 2050 under four land use scenarios:natural development scenario(NDS),ecological protection scenario(EPS),cultivated land protection scenario(CPS),and urban development scenario(UDS)using the patch-generating land use simulation(PLUS)model,and quantified the influences of natural and human factors on the spatial differentiation of ECS using the geographical detector(Geodetector).Results showed that the total ECS of the study area initially increased from 1985 until reaching a peak at 402.36×10^(6) t in 2010,followed by a decreasing trend to 2050.The spatial distribution of ECS was characterized by high values in the eastern and southern parts of the study area,and low values in the western and northern parts.Between 1985 and 2020,land use changes occurred mainly through the expansion of cultivated land,woodland,and construction land at the expense of unused land.The total ECS in 2050 under different land use scenarios(ranked as EPS>CPS>NDS>UDS)would be lower than that in 2020.Nighttime light was the largest contributor to the spatial differentiation of ECS,with soil type and annual mean temperature being the major natural driving factors.Findings of this study could provide guidance on the ecological construction and high-quality development in arid and semi-arid areas.展开更多
文摘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.
文摘[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.
基金supported by the Major program of Natural Science Foundation of Shandong Province(No.ZR2020ZD30)the National Natural Science Foundation of China(Nos.11775133,U2167202,U1432119).
文摘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.
基金National Natural Science Foundations of China(No.81173024)to professor Qiang Fu is gratefully acknowledged.The authors also thank Xi’an Insti-tute of Food and Drug Control for providing the facilities and necessary equipments.
文摘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 60C 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.
基金supported by the National Natural Science Foundation of China (Nos.12275007, U1867214, 11775004)the funding from the State Key Laboratory of Nuclear Physics and Technology,Peking University,China (No. NPT2021ZZ01)funding from heavy Ion Research Facility,Lanzhou,China (No. HIR2021PY002)。
文摘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.
基金This work was supported by the National Key Research and Development Program(Nos.2022YFB3503600 and 2021YFA0718500)Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDA15360102)National Natural Science Foundation of China(Nos.12273042 and 12075258).
文摘The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic X-rays.The nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton electrons.Despite the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 keV.The NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma rays.Furthermore,we explored the underlying causes of the observed nonlinearity in these crystals.This study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.
基金supported by the Innovation Projects for Overseas Returnees of Ningxia Hui Autonomous Region-Study on Multi-Scenario Land Use Optimization and Carbon Storage in the Ningxia Section of Yellow River Basin(202303)the National Natural Science Foundation of China(42067022,41761066)the Natural Science Foundation of Ningxia Hui Autonomous Region,China(2022AAC03024)。
文摘Regional sustainable development necessitates a holistic understanding of spatiotemporal variations in ecosystem carbon storage(ECS),particularly in ecologically sensitive areas with arid and semi-arid climate.In this study,we calculated the ECS in the Ningxia Section of Yellow River Basin,China from 1985 to 2020 using the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model based on land use data.We further predicted the spatial distribution of ECS in 2050 under four land use scenarios:natural development scenario(NDS),ecological protection scenario(EPS),cultivated land protection scenario(CPS),and urban development scenario(UDS)using the patch-generating land use simulation(PLUS)model,and quantified the influences of natural and human factors on the spatial differentiation of ECS using the geographical detector(Geodetector).Results showed that the total ECS of the study area initially increased from 1985 until reaching a peak at 402.36×10^(6) t in 2010,followed by a decreasing trend to 2050.The spatial distribution of ECS was characterized by high values in the eastern and southern parts of the study area,and low values in the western and northern parts.Between 1985 and 2020,land use changes occurred mainly through the expansion of cultivated land,woodland,and construction land at the expense of unused land.The total ECS in 2050 under different land use scenarios(ranked as EPS>CPS>NDS>UDS)would be lower than that in 2020.Nighttime light was the largest contributor to the spatial differentiation of ECS,with soil type and annual mean temperature being the major natural driving factors.Findings of this study could provide guidance on the ecological construction and high-quality development in arid and semi-arid areas.
