The complication of adulterated ingredients in processed food items is widely observed in the food industry and remains a continuous disquiet for end users. This problem may affect consumers’ spiritual beliefs, likew...The complication of adulterated ingredients in processed food items is widely observed in the food industry and remains a continuous disquiet for end users. This problem may affect consumers’ spiritual beliefs, likewise with their fitness and diet. Hence commercial foods should be scrutinized for the precision of the avowed ingredients. This study is dedicated to developing a Fluorescent light Spectroscope to identify the pork adulteration. A simple way of DNA extraction process has been introduced to make the system more convenient. The spectral bands linked with pork fat (PF), beef fat (BF) and their combinations in different food formulation were skimmed, and recognized by correlating them to those spectroscopically illustrative to clean Pork or PF and other different items. Every material has the properties to absorb some light of specific wavelength, and our activity is to determine thus wavelength range at which are absorbed or make any change by the target material. The findings have revealed that spectroscopy can be used as one of the procedures to detect and quantify of pork in different foods and beverages formulation for Halal verification purposes. Special laborious procedures and equipment both are essential for the existing testing methods named RT-PCR (Reverse transcription-polymerase chain reaction) and ELISA (enzyme-linked immunosorbent assay). Most of the food processors and dealers are not skillful to conduct sufficient testing for their products with all these sample preparation, extraction, analysis, and obtaining results which can be overcome by our proposed setup.展开更多
A multi Fiber Spectroscope at Kiso Observatory is under consideration as our next instrument. In this paper we report an overview of our instrument and a scientific target of survey project. We are going to attach mul...A multi Fiber Spectroscope at Kiso Observatory is under consideration as our next instrument. In this paper we report an overview of our instrument and a scientific target of survey project. We are going to attach multi fiber system at the prime focus of Kiso 150m Schmidt telescope. This telescope has some advantage for our project. First, the effciency in survey for the objects, which number density is 0 1 to 10/degree 2, is higher than other multi object system due to the wide field of view (6 °×6 °). Second, an optics of telescope is well matched to fiber numerical aperture (NA) at an input end of fiber. Moreover, taking a focal ratio degradation (FRD) and scrambling property into account, since the light from object does not move at the entrance slit of spectroscope, we could get spectroscopic data stably with this system. We select a fiber with 100μm core which corresponding to 6 arcsec on focal plane, that is matched with a typical seeing (3 arcsec) at Kiso Observatory and set 150 fibers to one field. For efficient observations, it is necessary to arrange fibers accurately within an accuracy of ±25μm on the curved focal plane during a typical exposure time (1 hour). Therefore we examine a particular positioner specialized for curved surface. We also develop a spectroscope that is suited for a fast focal ratio and proceed with making its design. One of our main key projects with this system is a non biased survey for solar neighbour stars. We are now establishing a new metallicity determination method that easily and reliably measures a metallicity from low dispersion spectra. (see Itoh it et al. 1998) As we consider our main target as Galactic objects and low resolution (R is around 1000), we could observe a star with 17 mag at V band (1 hour exposure).展开更多
As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such ...As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such as lower photoluminescence quantum yield(PLQY),complex synthetic pathways,uncontrollable emission spectra,and insufficient photostability.In this study,CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra.Then their ensemble spectroscopic properties during nucleation formation,alloying,and ZnS shell growth processes were systematically investigated.PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In,Zn^(2+)doping and ZnS shell growth.In particular,CuInZnS@ZnS QDs possess a significantly long emission lifetime(up to 750 ns),high PLQY(up to 85%),and excellent crystallinity.Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model.By controlling the stoichiometric ratio of Cu/In,two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects.Therefore,this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.展开更多
Unlike primary metabolites,secondary metabolites serve critical ecological functions,including plant protection,stress tolerance,and symbiosis.This review focuses on extracting,separating,and identifying the major cla...Unlike primary metabolites,secondary metabolites serve critical ecological functions,including plant protection,stress tolerance,and symbiosis.This review focuses on extracting,separating,and identifying the major classes of secondary metabolites,including alkaloids,terpenoids,phenolics,glycosides,saponins,and coumarins.It describes optimized methods regarding plant selection,extraction by solvents,and purification of the metabolites,highlighting the latest advancements in chromatographic and spectroscopic techniques.The review also describes some of the most important problems,such as the instability of the compounds or diversity of the structures,and discusses emerging technologies that solve these issues.Moreover,it examines the secondary roles of these metabolites in medicine,such as anticancer and antimicrobial drugs,sustainable agriculture biopesticides,and environmental ecology-also known as allelopathy and bioindicators.It combines traditional ethnobotanical approaches with contem-porary science,demonstrating the vital need to protect biodiversity in key ecosystems such as tropical rainforests,mountain regions,coral reefs,and arid zones as a foundation for anticipatory bio-discoveries.It organizes the methodological frameworks and outlines the steps needed to enhance the extraction of bioactive compounds from natural sources.展开更多
To ensure the safety and efficacy of Chinese herbs,it is of great significance to conduct rapid quality detection of Chinese herbs at every link of their supply chain.Spectroscopic technology can reflect the overall c...To ensure the safety and efficacy of Chinese herbs,it is of great significance to conduct rapid quality detection of Chinese herbs at every link of their supply chain.Spectroscopic technology can reflect the overall chemical composition and structural characteristics of Chinese herbs,with the multi-component and multitarget characteristics of Chinese herbs.This review took the genus Paris as an example,and applications of spectroscopic technology with machine learning(ML)in supply chain of the genus Paris from seeds to medicinal materials were introduced.The specific contents included the confirmation of germplasm resources,identification of growth years,cultivar,geographical origin,and original processing and processing methods.The potential application of spectroscopic technology in genus Paris was pointed out,and the prospects of combining spectroscopic technology with blockchain were proposed.The summary and prospects presented in this paper will be beneficial to the quality control of the genus Paris in all links of its supply chain,so as to rationally use the genus Paris resources and ensure the safety and efficacy of medication.展开更多
Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In ...Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In this study,we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7,synthesized via thermal injection and atomic layer(c-ALD)deposition techniques.Through a combination of spectroscopic ellipsometry(SE)and first-principles calculations,we demonstrate the significant tunability of the bandgap,refractive index,and extinction coefficient,driven by quantum confinement effects.Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases.Furthermore,by employing a detailed analysis of the absorption spectra,accounting for exciton localization and asymmetric broadening,we precisely capture the relationship between monolayer number and exciton binding energy.These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.展开更多
Phytochemical investigation of the branches of Viburnum awabuki K.Koch led to the isolation of thirteen known compounds,including five lignans(1-5),one phytosterol(6),two phenylpropanoids(7-8),one chromone derivative(...Phytochemical investigation of the branches of Viburnum awabuki K.Koch led to the isolation of thirteen known compounds,including five lignans(1-5),one phytosterol(6),two phenylpropanoids(7-8),one chromone derivative(9),three pentacyclic triterpenoids(10-12),and one glyceride(13).The structures of these compounds were elucidated through extensive spectroscopic analyses and comparison of experimental data with literature data.Additionally,the chemotaxonomic significance of the isolated secondary metabolites was also discussed.展开更多
The interstellar medium molecule thiocarbonyl thioketen,H_(2)CCS,has several stable isomers and has received considerable attention of as-tronomical observation in recent years.The positions of H,C,and S atoms of thre...The interstellar medium molecule thiocarbonyl thioketen,H_(2)CCS,has several stable isomers and has received considerable attention of as-tronomical observation in recent years.The positions of H,C,and S atoms of three isomers lead to di-verse dipole moments and spectro-scopic constants.The anharmonic force field and spectroscopic con-stants of thiocarbonyl thioketen and its isomers are calculated using MP2,B3LYP,and CCSD(T)methods employing correlation consistent basis sets.Molecule structures,rotational spectroscopic constants,and fundamental frequencies are compared with the available experimental data for thiocarbonyl thioketen.Ro-vibrational interaction constants,anharmonic constants,cubic and quartic force constants are predicted for thiocarbonyl thioketen.In addition,some rotational and vibrational spectroscopic parameters are predict-ed with the same level of theory for thioacetylene,HCCSH,and thiirene,(CH)_(2)S.The predic-tions of these spectroscopic constants are expected to guide the future astronomical observa-tion and high resolution experimental work for C_(2)H_(2)S isomers.展开更多
Lithium-sulfur battery(LSB)has attracted worldwide attention owing to its overwhelmingly high theoretical energy density of 2600Wh/kg due to the unique 16-electron electrochemical conversion reaction of elemental sulf...Lithium-sulfur battery(LSB)has attracted worldwide attention owing to its overwhelmingly high theoretical energy density of 2600Wh/kg due to the unique 16-electron electrochemical conversion reaction of elemental sulfur(S_(8))[1].However,the electrochemical conversion reaction of S_(8) is an exceedingly complex process that involves the generation of multiple intermediates(e.g.,lithium polysulfides(LiPSs))and multiphase transitions[1,2].Currently,the mechanistic investigations of the electrochemical conversion reaction of S_(8) upon discharging a LSB cell heavily rely on electrochemical titration and spectroscopic techniques[3].Nevertheless,the considerable complexity and intrinsic instability of the LSB system present substantial obstacles to obtaining accurate information for all sulfur-containing species,which significantly obstructs in-depth elucidation of the fundamental discharge mechanism of LSB[3,4].展开更多
The spectroscopic and transition properties of strontium chloride(SrCl)are investigated based on the theoretical approach of ab initio quantum chemistry.The calculation accuracy is improved by introducing Davidson cor...The spectroscopic and transition properties of strontium chloride(SrCl)are investigated based on the theoretical approach of ab initio quantum chemistry.The calculation accuracy is improved by introducing Davidson correction,core-valence correlation(CV),the scalar relativistic and spin–orbit coupling(SOC)effects.The results show that the spectroscopic constants of X^(2)S^(+)and A^(2)∏states are consistent with the experimental results.The spectroscopic and molecular constants of most highly excited electronic states are reported for the first time.The permanent dipole moment(PDMs)and the spin–orbit(SO)matrix element have a sudden change for the avoidance of crossing.The potential energy curves(PECs)of the 14 L–S states split into 30Ωstates.The splitting energy of A^(2)∏is 290.76 cm^(-1),which has a little difference from the experimental value 295.597 cm^(-1).Finally,the transition properties are given,including transition dipole moment(TDMs),Franck–Canton factor(FCFs)and radiation lifetime.It is found that the calculated radiation lifetime is in the order of 10 ns.The research will provide a theoretical reference for the feasibility of laser cooling of SrCl molecule.The dataset that supported the findings of this study is available in Science Data Bank,with the link https://www.doi.org/10.57760/sciencedb.j00113.00218.展开更多
We present a comprehensive mid-infrared spectroscopic survey of 124 Herbig Ae/Be stars using newly processed Spitzer/IRS spectra from the newly released CASSISjuice database.Based on prominent dust and molecular signa...We present a comprehensive mid-infrared spectroscopic survey of 124 Herbig Ae/Be stars using newly processed Spitzer/IRS spectra from the newly released CASSISjuice database.Based on prominent dust and molecular signatures(polycyclic aromatic hydrocarbons(PAHs),silicates,and hydrogenated amorphous carbons),we classify the stars into five groups.Our analysis reveals that 64%of the spectra show PAH emission,with detections peaking in the stellar effective temperature range 7000–11,000 K(B9–A5).Silicate features appear in 50%of the sample and likewise diminish at higher temperatures.Additionally,we find that future PAH studies can focus on Herbig Ae/Be stars with a spectral index n_(2−24)>−1 and flared morphologies to maximize PAH detections.The 6.2μm PAH band is the most frequently observed in our sample,shifting blueward with increasing stellar temperature,and this is the largest sample yet used to test that peak shift.The weaker 6.0μm feature does not shift with 6.2μm,implying a distinct origin of C=O(carbonyl)or olefinic C=C stretching relative to C–C vibrations.We examined the 11.0/11.2μm PAH ratio using high-resolution Spitzer spectra for the first time in a sample of Herbig Ae/Be stars,finding a range of ionization conditions.This study provides a strong foundation for future JWST observations of intermediate-mass pre-main-sequence stars.展开更多
During the total solar eclipse of 2013 November 3, a fiber-based spectrometer captured the flash spectrum within the wavelength range of 5162–5325Å, with the field-of-view positioned approximately 0.04 R⊙above ...During the total solar eclipse of 2013 November 3, a fiber-based spectrometer captured the flash spectrum within the wavelength range of 5162–5325Å, with the field-of-view positioned approximately 0.04 R⊙above the east limb, near the second-contact point. This placement near the innermost corona, together with the nearby Baily's beads, enabled the detection of emission lines from the photosphere, lower chromosphere, and corona in the same spectral frame. The higher field-of-view made the coronal line Fe XIV 5303Åmore visible, while the reduced intensity of photospheric and lower chromospheric light, caused by terrestrial scattering, also influenced the observed spectrum. Meanwhile, we selected 18 flash emission lines to measure the ratio of the relative line height of the flash emission line to the relative line depth of the corresponding solar absorption line. This ratio serves as a diagnostic of the source function, minimizing opacity effects. Comparison of disk and flash spectra shows that this ratio increases for spectral lines at greater formation heights, being strongest for chromospheric lines(particularly Fe II), moderate for photospheric low-FIP lines, and weakest for photospheric neutral lines. This trend suggests a rising source function with formation height, potentially linked to increasing electron temperatures or influenced by factors observed in flash spectra near active regions as reported in earlier studies.展开更多
Slitless spectroscopy onboard space telescopes is a powerful tool to detect emission-line objects such as emissionline galaxies(ELGs)and quasars.In this work,we present a study of ELGs observed with slitless spectrosc...Slitless spectroscopy onboard space telescopes is a powerful tool to detect emission-line objects such as emissionline galaxies(ELGs)and quasars.In this work,we present a study of ELGs observed with slitless spectroscopy by the Hubble Space Telescope(HST)in a deep field of~44 arcmin^(2).This is one of the deepest HST fields with a wealth of imaging and spectral data.In particular,previous VLT/MUSE observations have covered this field and identified a large number of ELGs.We reduce the HST spectra using the latest pipeline with a forward modeling algorithm and construct a sample of ELGs.By comparing with the MUSE spectra,we characterize our ELG detection in the HST spectra,including the impact of the line flux,line width,signal-to-noise ratio,etc.We find that the morphological broadening may affect the detection of ELGs,such that more compact sources are easier to be detected in slitless spectra.We discuss its implications to future slitless spectroscopic surveys that will be carried out by the China Space Station Telescope(CSST)and find that the CSST slitless spectroscopy has a capability comparable to that of HST in terms of the detection of emission lines.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
The Glauber/eikonal model is a widely used tool for studying intermediate-and high-energy nuclear reactions.When calculating the Glauber/eikonal model phase shift functions,the optical limit approximation(OLA)is often...The Glauber/eikonal model is a widely used tool for studying intermediate-and high-energy nuclear reactions.When calculating the Glauber/eikonal model phase shift functions,the optical limit approximation(OLA)is often used.The OLA neglects the multiple scattering of the constituent nucleons in the projectile and target nuclei.However,the nucleon-target version of the Glauber model(the NTG model)proposed by Abu-Ibrahim and Suzuki includes multiple scattering effects between the projectile nucleons and target nuclei.The NTG model was found to improve the description of the elastic scattering angular distributions and total reaction cross sections of some light heavy-ion systems with respect to the OLA.In this work,we study the single-nucleon removal reactions(SNRRs)induced by carbon isotopes on ^(12)C and ^(9)Be targets using both the NTG model and the OLA.Reduction factors(RFs)of the single-nucleon spectroscopic factors were obtained by comparing the experimental and theoretical SNRR cross sections.On average,the RFs obtained with the NTG model were smaller than those obtained using the OLA by 7.8%,in which the average difference in one-neutron removal was 10.6% and that in one-proton removal was 4.2%.However,the RFs were still strongly dependent on the neutron-proton asymmetryΔS of the projectile nuclei,even when the NTG model was used.展开更多
The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution.To advance this research,countries have made significant investments in constructing large lowfreq...The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution.To advance this research,countries have made significant investments in constructing large lowfrequency radio telescope arrays,such as the Low Frequency Array and the Square Kilometre Array Phase 1 Low Frequency.These instruments are pivotal for radio astronomy research.However,challenges such as ionospheric plasma interference,ambient radio noise,and instrument-related effects have become increasingly prominent,posing major obstacles in cosmology research.To address these issues,this paper proposes an efficient signal processing method that combines wavelet transform and mathematical morphology.The method involves the following steps:Background Subtraction:Background interference in radio observation signals is eliminated.Wavelet Transform:The signal,after removing background noise,undergoes a two-dimensional discrete wavelet transform.Threshold processing is then applied to the wavelet coefficients to effectively remove interference components.Wavelet Inversion:The processed signal is reconstructed using wavelet inversion.Mathematical Morphology:The reconstructed signal is further optimized using mathematical morphology to refine the results.Experimental verification was conducted using solar observation data from the Xinjiang Observatory and the Yunnan Observatory.The results demonstrate that this method successfully removes interference signals while preserving useful signals,thus improving the accuracy of radio astronomy observations and reducing the impact of radio frequency interference.展开更多
As part of the LAMOST medium-resolution spectroscopic survey,the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas.This su...As part of the LAMOST medium-resolution spectroscopic survey,the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas.This survey plans to obtain the spectroscopic parameters such as radial velocity and metal abundances of member stars and provide data support for further study on the chemical and dynamical characteristics and evolution of open clusters in combination with Gaia data.We have completed the observations on ten open cluster fields and obtained 235184 medium-resolution spectra of 133792 stars.Based on the data analyzed of LAMOST DR11v1.1,for some clusters of particular concern,it is found that the sampling ratio of members stars with Gmag<15 mag can reach 70%,which indicates that the LAMOST-MRS-O has reached our initial design goal.展开更多
The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristi...The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristics of bound and continuum states in dense matter are modeled by a valence-band-like structure in a generalized ion-sphere approach with states that are either bound,free,or mixed.The self-consistent combination of this model with the Dirac wave equations of multielectron bound states allows one to fully respect the Pauli principle and to take into account the exact nonlocal exchange terms.The generalized method allows very high precision without implication of calibration shifts and scaling parameters and therefore has predictive power.This leads to new insights in the analysis of various data.The simple ionization model representing the K-edge is generalized to excitation–ionization phenomena resulting in an advanced interpretation of ionization depression data in near-solid-density plasmas.The model predicts scaling relations along the isoelectronic sequences and the existence of bound M-states that are in excellent agreement with experimental data,whereas other methods have failed.The application to unexplained data from compound materials also gives good agreement without the need to invoke any additional assumptions in the generalized model,whereas other methods have lacked consistency.展开更多
AR Aur A+B is a close binary of astrophysical interest because dissimilar surface compositions are reported between similar late B-type dwarfs.A new spectroscopic study on this system was carried out based on the dise...AR Aur A+B is a close binary of astrophysical interest because dissimilar surface compositions are reported between similar late B-type dwarfs.A new spectroscopic study on this system was carried out based on the disentangled spectra,in order to determine their atmospheric parameters and elemental abundances.The effective temperature and microturbulence(determined from the equivalent widths of Fe II lines)turned out to be(11,150 K,0.9 km s^(-1))and(10,650 K,0.1 km s^(-1))for A and B,respectively.The chemical abundances of 28 elements were then derived while taking into account the non-LTE effect for Z≤15 elements(Z:atomic number).The following trends were elucidated for[X/H](abundance of X relative to the Sun):(1)Qualitatively,[X/H]shows a rough global tendency to increase with Z,with the gradient steeper for A than for B.(2)However,considerable dispersion is involved for A,since prominently large peculiarities are seen in specific elements reflecting the characteristics of HgMn stars(e.g.,very deficient N,Al,Sc,Ni;markedly overabundant P,Mn).(3)In contrast,the Z-dependence of[X/H]for B tends to be nearly linear with only a small dispersion.These observational facts may serve as a key to understanding the critical condition for the emergence of the chemical anomaly.展开更多
The inner Milky Way disk globular cluster NGC 6362 appears to exhibit tidal tails composed of stars that have proper motions and positions in the color–magnitude diagram similar to those of cluster stars. Because rec...The inner Milky Way disk globular cluster NGC 6362 appears to exhibit tidal tails composed of stars that have proper motions and positions in the color–magnitude diagram similar to those of cluster stars. Because recent results seem also to show that these stars are distributed across the regions least affected by interstellar absorption and reproduce the observed composite star field density map, we carried out a detailed spectroscopic analysis of a number of chemical element abundances of tidal tail star candidates in order to investigate the relationship between them and NGC 6362. From European Southern Observatory's VLT@FLAMES spectra we found that the red giant branch stars selected as the cluster's tidal tail stars neither have overall metallicities nor abundances of Mg, Ca, Sc, Ti, Cr, Ni and Ba similar to the cluster's ones. Moreover, they are mainly alike to stars that belong to the Milky Way thick disk, some of them could be part of the thin disk and a minor percentage could belong to the Milky Way halo star population. On the other hand, since the resulting radial velocities do not exhibit a distribution function similar to that of the cluster's stars, we concluded that looking for kinematic properties similar to those of the cluster would not seem to be as suitable of an approach for selecting the cluster's tidal tail stars as previously thought.展开更多
文摘The complication of adulterated ingredients in processed food items is widely observed in the food industry and remains a continuous disquiet for end users. This problem may affect consumers’ spiritual beliefs, likewise with their fitness and diet. Hence commercial foods should be scrutinized for the precision of the avowed ingredients. This study is dedicated to developing a Fluorescent light Spectroscope to identify the pork adulteration. A simple way of DNA extraction process has been introduced to make the system more convenient. The spectral bands linked with pork fat (PF), beef fat (BF) and their combinations in different food formulation were skimmed, and recognized by correlating them to those spectroscopically illustrative to clean Pork or PF and other different items. Every material has the properties to absorb some light of specific wavelength, and our activity is to determine thus wavelength range at which are absorbed or make any change by the target material. The findings have revealed that spectroscopy can be used as one of the procedures to detect and quantify of pork in different foods and beverages formulation for Halal verification purposes. Special laborious procedures and equipment both are essential for the existing testing methods named RT-PCR (Reverse transcription-polymerase chain reaction) and ELISA (enzyme-linked immunosorbent assay). Most of the food processors and dealers are not skillful to conduct sufficient testing for their products with all these sample preparation, extraction, analysis, and obtaining results which can be overcome by our proposed setup.
文摘A multi Fiber Spectroscope at Kiso Observatory is under consideration as our next instrument. In this paper we report an overview of our instrument and a scientific target of survey project. We are going to attach multi fiber system at the prime focus of Kiso 150m Schmidt telescope. This telescope has some advantage for our project. First, the effciency in survey for the objects, which number density is 0 1 to 10/degree 2, is higher than other multi object system due to the wide field of view (6 °×6 °). Second, an optics of telescope is well matched to fiber numerical aperture (NA) at an input end of fiber. Moreover, taking a focal ratio degradation (FRD) and scrambling property into account, since the light from object does not move at the entrance slit of spectroscope, we could get spectroscopic data stably with this system. We select a fiber with 100μm core which corresponding to 6 arcsec on focal plane, that is matched with a typical seeing (3 arcsec) at Kiso Observatory and set 150 fibers to one field. For efficient observations, it is necessary to arrange fibers accurately within an accuracy of ±25μm on the curved focal plane during a typical exposure time (1 hour). Therefore we examine a particular positioner specialized for curved surface. We also develop a spectroscope that is suited for a fast focal ratio and proceed with making its design. One of our main key projects with this system is a non biased survey for solar neighbour stars. We are now establishing a new metallicity determination method that easily and reliably measures a metallicity from low dispersion spectra. (see Itoh it et al. 1998) As we consider our main target as Galactic objects and low resolution (R is around 1000), we could observe a star with 17 mag at V band (1 hour exposure).
基金Fund Project for Transformation of Scientific and Technological Achievements of Jiangsu Province of China(BA2023020)。
文摘As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such as lower photoluminescence quantum yield(PLQY),complex synthetic pathways,uncontrollable emission spectra,and insufficient photostability.In this study,CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra.Then their ensemble spectroscopic properties during nucleation formation,alloying,and ZnS shell growth processes were systematically investigated.PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In,Zn^(2+)doping and ZnS shell growth.In particular,CuInZnS@ZnS QDs possess a significantly long emission lifetime(up to 750 ns),high PLQY(up to 85%),and excellent crystallinity.Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model.By controlling the stoichiometric ratio of Cu/In,two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects.Therefore,this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.
文摘Unlike primary metabolites,secondary metabolites serve critical ecological functions,including plant protection,stress tolerance,and symbiosis.This review focuses on extracting,separating,and identifying the major classes of secondary metabolites,including alkaloids,terpenoids,phenolics,glycosides,saponins,and coumarins.It describes optimized methods regarding plant selection,extraction by solvents,and purification of the metabolites,highlighting the latest advancements in chromatographic and spectroscopic techniques.The review also describes some of the most important problems,such as the instability of the compounds or diversity of the structures,and discusses emerging technologies that solve these issues.Moreover,it examines the secondary roles of these metabolites in medicine,such as anticancer and antimicrobial drugs,sustainable agriculture biopesticides,and environmental ecology-also known as allelopathy and bioindicators.It combines traditional ethnobotanical approaches with contem-porary science,demonstrating the vital need to protect biodiversity in key ecosystems such as tropical rainforests,mountain regions,coral reefs,and arid zones as a foundation for anticipatory bio-discoveries.It organizes the methodological frameworks and outlines the steps needed to enhance the extraction of bioactive compounds from natural sources.
基金funded by the Special Program for the Major Science and Technology Projects of Yunnan Province,China(Grant No.:202202AE090001).
文摘To ensure the safety and efficacy of Chinese herbs,it is of great significance to conduct rapid quality detection of Chinese herbs at every link of their supply chain.Spectroscopic technology can reflect the overall chemical composition and structural characteristics of Chinese herbs,with the multi-component and multitarget characteristics of Chinese herbs.This review took the genus Paris as an example,and applications of spectroscopic technology with machine learning(ML)in supply chain of the genus Paris from seeds to medicinal materials were introduced.The specific contents included the confirmation of germplasm resources,identification of growth years,cultivar,geographical origin,and original processing and processing methods.The potential application of spectroscopic technology in genus Paris was pointed out,and the prospects of combining spectroscopic technology with blockchain were proposed.The summary and prospects presented in this paper will be beneficial to the quality control of the genus Paris in all links of its supply chain,so as to rationally use the genus Paris resources and ensure the safety and efficacy of medication.
基金supported by the National Natural Science Foundation of China(62205180)the Natural Science Foundation of Shandong Province(ZR2022QF029)the Taishan Scholar Program of Shandong Province(Young Scientist).
文摘Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In this study,we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7,synthesized via thermal injection and atomic layer(c-ALD)deposition techniques.Through a combination of spectroscopic ellipsometry(SE)and first-principles calculations,we demonstrate the significant tunability of the bandgap,refractive index,and extinction coefficient,driven by quantum confinement effects.Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases.Furthermore,by employing a detailed analysis of the absorption spectra,accounting for exciton localization and asymmetric broadening,we precisely capture the relationship between monolayer number and exciton binding energy.These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.
基金supported by the National Natural Science Foundation of China(No.32370425).
文摘Phytochemical investigation of the branches of Viburnum awabuki K.Koch led to the isolation of thirteen known compounds,including five lignans(1-5),one phytosterol(6),two phenylpropanoids(7-8),one chromone derivative(9),three pentacyclic triterpenoids(10-12),and one glyceride(13).The structures of these compounds were elucidated through extensive spectroscopic analyses and comparison of experimental data with literature data.Additionally,the chemotaxonomic significance of the isolated secondary metabolites was also discussed.
基金supported by the Natural Science Foundation of Inner Mongolia(No.2020MS01023).
文摘The interstellar medium molecule thiocarbonyl thioketen,H_(2)CCS,has several stable isomers and has received considerable attention of as-tronomical observation in recent years.The positions of H,C,and S atoms of three isomers lead to di-verse dipole moments and spectro-scopic constants.The anharmonic force field and spectroscopic con-stants of thiocarbonyl thioketen and its isomers are calculated using MP2,B3LYP,and CCSD(T)methods employing correlation consistent basis sets.Molecule structures,rotational spectroscopic constants,and fundamental frequencies are compared with the available experimental data for thiocarbonyl thioketen.Ro-vibrational interaction constants,anharmonic constants,cubic and quartic force constants are predicted for thiocarbonyl thioketen.In addition,some rotational and vibrational spectroscopic parameters are predict-ed with the same level of theory for thioacetylene,HCCSH,and thiirene,(CH)_(2)S.The predic-tions of these spectroscopic constants are expected to guide the future astronomical observa-tion and high resolution experimental work for C_(2)H_(2)S isomers.
文摘Lithium-sulfur battery(LSB)has attracted worldwide attention owing to its overwhelmingly high theoretical energy density of 2600Wh/kg due to the unique 16-electron electrochemical conversion reaction of elemental sulfur(S_(8))[1].However,the electrochemical conversion reaction of S_(8) is an exceedingly complex process that involves the generation of multiple intermediates(e.g.,lithium polysulfides(LiPSs))and multiphase transitions[1,2].Currently,the mechanistic investigations of the electrochemical conversion reaction of S_(8) upon discharging a LSB cell heavily rely on electrochemical titration and spectroscopic techniques[3].Nevertheless,the considerable complexity and intrinsic instability of the LSB system present substantial obstacles to obtaining accurate information for all sulfur-containing species,which significantly obstructs in-depth elucidation of the fundamental discharge mechanism of LSB[3,4].
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11564019,11147158,and 12464032)the Department of Education Foundation of Jiangxi Province of China(Grant No.GJJ2401520).
文摘The spectroscopic and transition properties of strontium chloride(SrCl)are investigated based on the theoretical approach of ab initio quantum chemistry.The calculation accuracy is improved by introducing Davidson correction,core-valence correlation(CV),the scalar relativistic and spin–orbit coupling(SOC)effects.The results show that the spectroscopic constants of X^(2)S^(+)and A^(2)∏states are consistent with the experimental results.The spectroscopic and molecular constants of most highly excited electronic states are reported for the first time.The permanent dipole moment(PDMs)and the spin–orbit(SO)matrix element have a sudden change for the avoidance of crossing.The potential energy curves(PECs)of the 14 L–S states split into 30Ωstates.The splitting energy of A^(2)∏is 290.76 cm^(-1),which has a little difference from the experimental value 295.597 cm^(-1).Finally,the transition properties are given,including transition dipole moment(TDMs),Franck–Canton factor(FCFs)and radiation lifetime.It is found that the calculated radiation lifetime is in the order of 10 ns.The research will provide a theoretical reference for the feasibility of laser cooling of SrCl molecule.The dataset that supported the findings of this study is available in Science Data Bank,with the link https://www.doi.org/10.57760/sciencedb.j00113.00218.
基金financial support from CHRIST(Deemed to be University,Bangalore)through the SEED money projects(No:SMSS-2335,11/2023&SMSS-2220,12/2022)by the SERB project(CRG/2023/005271).
文摘We present a comprehensive mid-infrared spectroscopic survey of 124 Herbig Ae/Be stars using newly processed Spitzer/IRS spectra from the newly released CASSISjuice database.Based on prominent dust and molecular signatures(polycyclic aromatic hydrocarbons(PAHs),silicates,and hydrogenated amorphous carbons),we classify the stars into five groups.Our analysis reveals that 64%of the spectra show PAH emission,with detections peaking in the stellar effective temperature range 7000–11,000 K(B9–A5).Silicate features appear in 50%of the sample and likewise diminish at higher temperatures.Additionally,we find that future PAH studies can focus on Herbig Ae/Be stars with a spectral index n_(2−24)>−1 and flared morphologies to maximize PAH detections.The 6.2μm PAH band is the most frequently observed in our sample,shifting blueward with increasing stellar temperature,and this is the largest sample yet used to test that peak shift.The weaker 6.0μm feature does not shift with 6.2μm,implying a distinct origin of C=O(carbonyl)or olefinic C=C stretching relative to C–C vibrations.We examined the 11.0/11.2μm PAH ratio using high-resolution Spitzer spectra for the first time in a sample of Herbig Ae/Be stars,finding a range of ionization conditions.This study provides a strong foundation for future JWST observations of intermediate-mass pre-main-sequence stars.
基金supported by the National Natural Science Foundation of China(NSFC)under grant Nos.12473054 and 12127901the Strategic Priority Research Program of the Chinese Academy of Sciences under grant No.XDB0560000+1 种基金Yunnan Key Laboratory of Solar Physics and Space Science under No.202205AG070009Yunnan Fundamental Research Projects under No.202105AC160085.
文摘During the total solar eclipse of 2013 November 3, a fiber-based spectrometer captured the flash spectrum within the wavelength range of 5162–5325Å, with the field-of-view positioned approximately 0.04 R⊙above the east limb, near the second-contact point. This placement near the innermost corona, together with the nearby Baily's beads, enabled the detection of emission lines from the photosphere, lower chromosphere, and corona in the same spectral frame. The higher field-of-view made the coronal line Fe XIV 5303Åmore visible, while the reduced intensity of photospheric and lower chromospheric light, caused by terrestrial scattering, also influenced the observed spectrum. Meanwhile, we selected 18 flash emission lines to measure the ratio of the relative line height of the flash emission line to the relative line depth of the corresponding solar absorption line. This ratio serves as a diagnostic of the source function, minimizing opacity effects. Comparison of disk and flash spectra shows that this ratio increases for spectral lines at greater formation heights, being strongest for chromospheric lines(particularly Fe II), moderate for photospheric low-FIP lines, and weakest for photospheric neutral lines. This trend suggests a rising source function with formation height, potentially linked to increasing electron temperatures or influenced by factors observed in flash spectra near active regions as reported in earlier studies.
基金support from the National Key R&D Program of China(2022YFF0503401)the China Manned Space Project with No.CMS-CSST-2021-A05the National Natural Science Foundation of China(12225301)。
文摘Slitless spectroscopy onboard space telescopes is a powerful tool to detect emission-line objects such as emissionline galaxies(ELGs)and quasars.In this work,we present a study of ELGs observed with slitless spectroscopy by the Hubble Space Telescope(HST)in a deep field of~44 arcmin^(2).This is one of the deepest HST fields with a wealth of imaging and spectral data.In particular,previous VLT/MUSE observations have covered this field and identified a large number of ELGs.We reduce the HST spectra using the latest pipeline with a forward modeling algorithm and construct a sample of ELGs.By comparing with the MUSE spectra,we characterize our ELG detection in the HST spectra,including the impact of the line flux,line width,signal-to-noise ratio,etc.We find that the morphological broadening may affect the detection of ELGs,such that more compact sources are easier to be detected in slitless spectra.We discuss its implications to future slitless spectroscopic surveys that will be carried out by the China Space Station Telescope(CSST)and find that the CSST slitless spectroscopy has a capability comparable to that of HST in terms of the detection of emission lines.
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financially supported by the National Key R&D Program of China(No.2023YFA1606702)the National Natural Science Foundation of China(Nos.U2067205 and 12205098).
文摘The Glauber/eikonal model is a widely used tool for studying intermediate-and high-energy nuclear reactions.When calculating the Glauber/eikonal model phase shift functions,the optical limit approximation(OLA)is often used.The OLA neglects the multiple scattering of the constituent nucleons in the projectile and target nuclei.However,the nucleon-target version of the Glauber model(the NTG model)proposed by Abu-Ibrahim and Suzuki includes multiple scattering effects between the projectile nucleons and target nuclei.The NTG model was found to improve the description of the elastic scattering angular distributions and total reaction cross sections of some light heavy-ion systems with respect to the OLA.In this work,we study the single-nucleon removal reactions(SNRRs)induced by carbon isotopes on ^(12)C and ^(9)Be targets using both the NTG model and the OLA.Reduction factors(RFs)of the single-nucleon spectroscopic factors were obtained by comparing the experimental and theoretical SNRR cross sections.On average,the RFs obtained with the NTG model were smaller than those obtained using the OLA by 7.8%,in which the average difference in one-neutron removal was 10.6% and that in one-proton removal was 4.2%.However,the RFs were still strongly dependent on the neutron-proton asymmetryΔS of the projectile nuclei,even when the NTG model was used.
基金funded by the National Key Research and Development Program’s intergovernmental International Science and Technology Innovation Cooperation project,titled Remote Sensing and Radio Astronomy Observation of Space Weather in Low and Middle Latitudes(project number:2022YFE0140000)Supported by International Partnership Program of Chinese Academy of Sciences,grant No.114A11KYSB20200001。
文摘The 21 cm radiation of neutral hydrogen provides crucial information for studying the early universe and its evolution.To advance this research,countries have made significant investments in constructing large lowfrequency radio telescope arrays,such as the Low Frequency Array and the Square Kilometre Array Phase 1 Low Frequency.These instruments are pivotal for radio astronomy research.However,challenges such as ionospheric plasma interference,ambient radio noise,and instrument-related effects have become increasingly prominent,posing major obstacles in cosmology research.To address these issues,this paper proposes an efficient signal processing method that combines wavelet transform and mathematical morphology.The method involves the following steps:Background Subtraction:Background interference in radio observation signals is eliminated.Wavelet Transform:The signal,after removing background noise,undergoes a two-dimensional discrete wavelet transform.Threshold processing is then applied to the wavelet coefficients to effectively remove interference components.Wavelet Inversion:The processed signal is reconstructed using wavelet inversion.Mathematical Morphology:The reconstructed signal is further optimized using mathematical morphology to refine the results.Experimental verification was conducted using solar observation data from the Xinjiang Observatory and the Yunnan Observatory.The results demonstrate that this method successfully removes interference signals while preserving useful signals,thus improving the accuracy of radio astronomy observations and reducing the impact of radio frequency interference.
基金supported by the National Natural Science Foundation of China(NSFC)through grants 12090040,12090042,and 12073060the National Key R&D Program of China No.2019YFA0405501+2 种基金J.Z.acknowledges the Youth Innovation Promotion Association CASthe Science and Technology Commission of Shanghai Municipality(grant No.22dz1202400)the Program of Shanghai Academic/Technology Research Leader。
文摘As part of the LAMOST medium-resolution spectroscopic survey,the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas.This survey plans to obtain the spectroscopic parameters such as radial velocity and metal abundances of member stars and provide data support for further study on the chemical and dynamical characteristics and evolution of open clusters in combination with Gaia data.We have completed the observations on ten open cluster fields and obtained 235184 medium-resolution spectra of 133792 stars.Based on the data analyzed of LAMOST DR11v1.1,for some clusters of particular concern,it is found that the sampling ratio of members stars with Gmag<15 mag can reach 70%,which indicates that the LAMOST-MRS-O has reached our initial design goal.
基金supported by the NSFC under Grant Nos.11374315 and 12074395the Invited Scientist Program of CNRS at Ecole Polytechnique,Palaiseau,France。
文摘The capacity to predict X-ray transition and K-edge energies in dense finite-temperatur plasmas with high precision is of primary importance for atomic physics of matter under extreme conditions.The dual characteristics of bound and continuum states in dense matter are modeled by a valence-band-like structure in a generalized ion-sphere approach with states that are either bound,free,or mixed.The self-consistent combination of this model with the Dirac wave equations of multielectron bound states allows one to fully respect the Pauli principle and to take into account the exact nonlocal exchange terms.The generalized method allows very high precision without implication of calibration shifts and scaling parameters and therefore has predictive power.This leads to new insights in the analysis of various data.The simple ionization model representing the K-edge is generalized to excitation–ionization phenomena resulting in an advanced interpretation of ionization depression data in near-solid-density plasmas.The model predicts scaling relations along the isoelectronic sequences and the existence of bound M-states that are in excellent agreement with experimental data,whereas other methods have failed.The application to unexplained data from compound materials also gives good agreement without the need to invoke any additional assumptions in the generalized model,whereas other methods have lacked consistency.
文摘AR Aur A+B is a close binary of astrophysical interest because dissimilar surface compositions are reported between similar late B-type dwarfs.A new spectroscopic study on this system was carried out based on the disentangled spectra,in order to determine their atmospheric parameters and elemental abundances.The effective temperature and microturbulence(determined from the equivalent widths of Fe II lines)turned out to be(11,150 K,0.9 km s^(-1))and(10,650 K,0.1 km s^(-1))for A and B,respectively.The chemical abundances of 28 elements were then derived while taking into account the non-LTE effect for Z≤15 elements(Z:atomic number).The following trends were elucidated for[X/H](abundance of X relative to the Sun):(1)Qualitatively,[X/H]shows a rough global tendency to increase with Z,with the gradient steeper for A than for B.(2)However,considerable dispersion is involved for A,since prominently large peculiarities are seen in specific elements reflecting the characteristics of HgMn stars(e.g.,very deficient N,Al,Sc,Ni;markedly overabundant P,Mn).(3)In contrast,the Z-dependence of[X/H]for B tends to be nearly linear with only a small dispersion.These observational facts may serve as a key to understanding the critical condition for the emergence of the chemical anomaly.
基金Based on observations collected at the European Southern Observatory under ESO program(s)113.2661.001.
文摘The inner Milky Way disk globular cluster NGC 6362 appears to exhibit tidal tails composed of stars that have proper motions and positions in the color–magnitude diagram similar to those of cluster stars. Because recent results seem also to show that these stars are distributed across the regions least affected by interstellar absorption and reproduce the observed composite star field density map, we carried out a detailed spectroscopic analysis of a number of chemical element abundances of tidal tail star candidates in order to investigate the relationship between them and NGC 6362. From European Southern Observatory's VLT@FLAMES spectra we found that the red giant branch stars selected as the cluster's tidal tail stars neither have overall metallicities nor abundances of Mg, Ca, Sc, Ti, Cr, Ni and Ba similar to the cluster's ones. Moreover, they are mainly alike to stars that belong to the Milky Way thick disk, some of them could be part of the thin disk and a minor percentage could belong to the Milky Way halo star population. On the other hand, since the resulting radial velocities do not exhibit a distribution function similar to that of the cluster's stars, we concluded that looking for kinematic properties similar to those of the cluster would not seem to be as suitable of an approach for selecting the cluster's tidal tail stars as previously thought.
