Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao)...Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization.展开更多
Pseudocapacitive materials that store charges via reversible surface or near-surface faradaic reactions are capable of overcoming the capacity limitations of electrical double-layer capacitors.Revealing the structure...Pseudocapacitive materials that store charges via reversible surface or near-surface faradaic reactions are capable of overcoming the capacity limitations of electrical double-layer capacitors.Revealing the structure–activity relationship between the microstructural features of pseudocapacitive materials and their electrochemical performance on the atomic scale is the key to build high-performance capacitor-type devices containing ideal pseudocapacitance effect.Currently,the high brightness(flux),and spectral and coherent nature of synchrotron X-ray analytical techniques make it a powerful tool for probing the structure–property relationship of pseudocapacitive materials.Herein,we report a comprehensive and systematic review of four typical characterization techniques(synchrotron X-ray diffraction,pair distribution function[PDF]analysis,soft X-ray absorption spectroscopy,and hard X-ray absorption spectroscopy)for the study of pseudocapacitance mechanisms.In addition,we offered significant insights for understanding and identifying pseudocapacitance mechanisms(surface redox pseudocapacitance,intercalation pseudocapacitance,and the extrinsic pseudocapacitance phenomenon in battery materials)by combining in situ hard XAS and electrochemical analyses.Finally,a perspective for further depth of understanding into the pseudocapacitance mechanism using synchrotron X-ray analytical techniques is proposed.展开更多
There are many well-known analytical methods for determination of iron（Ⅱ） and iron（Ⅲ）. Among these methods： Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometr...There are many well-known analytical methods for determination of iron（Ⅱ） and iron（Ⅲ）. Among these methods： Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometric methods. In present study, two batch spectrophotometric, atomic absorption spectrometric and biolabo kit methods have been used for determination of iron（Ⅱ）, iron（Ⅲ） and total iron. The present methods have the advantages of high sensitivity, low cost reagent, low operation cost, simplicity, speed and their applications for determination of iron（Ⅱ） and iron（Ⅲ） in some serum samples of normal human and fl-thalasemia patients in Erbil city. For the first time especially in Erbil city attempts were made to use zero, first and second derivative spectra to identify the serum samples of some β-thallasemia patients from the normal human serum samples due to the appearance and resolution of peaks in both cases.展开更多
The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic p...The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic pollutants (EOPs) are among the biggest contributors to this burden. Herein we reviewed literature published for the period 2000–2023 on selected LOPs and EOPs in indoor dust and outdoor air in Africa to understand the occurrence, associated human health risks and common analytical techniques used to identify and quantify these contaminants. The findings revealed generally lower contamination levels for most pollutants than that in most regions outside Africa except for PCBs in outdoor air and OCPs in indoor settled dust. Apart from a few studies for polychlorinated biphenyls (PCBs), most studies reported hazard index (HI) values less than 1 for outdoor air and indoor dust exposure, which suggested negligible non-carcinogenic risks in children and adults. Gas Chromatography and mass spectrometry were the most frequently used analytical techniques for both air and dust probably due to their sensitivity and selectivity in detecting chemical traces at the pg m^(−3) and ng g^(−1) levels. Although the current contamination levels are generally low, their synergistic and cumulative effects may in the long run affect the environment and human health. There is also a paucity of data on most contaminants, especially for PCNs, and PFASs in both outdoor air and dust. Coordinated efforts are needed to limit the trade, importation, and disposal of products containing LOPs and EOPs in Africa.展开更多
The plant is a rich repository of useful secondary metabolites with profound medicinal potential.Saponins,one type of bioactive compound,are amphitheatric glycosides with one and more hydrophilic sugar and hydrophobic...The plant is a rich repository of useful secondary metabolites with profound medicinal potential.Saponins,one type of bioactive compound,are amphitheatric glycosides with one and more hydrophilic sugar and hydrophobic steroidal and terpenoid part.The former is known as steroidal saponin,and the latter is called terpenoid saponins.Steroidal saponin is mostly distributed among monocotyledon families such as Asparagaceae,Amaryllidaceae,Dioscoreaceae,Smilacaceae,and Liliaceae.Even though it is unusual,it could also be detected to some extent by dicotyledonous angiosperms,such as Plantaginaceae,Zygophyllaceae,Fabaceae,Asteraceae,and Solanaceae.It exhibits diverse pharmacological ability including antimicrobic,anti‑inflammatory,cAMP phosphodiesterase inhibitory,antiadipogenic,bactericide,cardioprotective,antitumor,antidiabetic,cytotoxic activity,antifungal,antiviral,antioxidant,and hepatoprotective.Steroidal saponin timosaponin AIII from Anemarrhena asphodeloides has been found to possess antitumor activity.Diosgenin,another steroidal sapogenin,has the potential of preventing neurological diseases by affecting different signaling pathways,increasing bone formation,and increasing antithrombotic activity.Spicatoside A from Liriope platyphylla possesses anti‑inflammatory,antiasthma,and antiosteoclastogenic activities.TTB2 from Trillium tschonoskii exhibits anticancer potential.The cell cycle arrest and ROS‑dependent autophagy are induced by polyphyllin I.These diverse biological activities of steroidal saponins are attributed to the variability of their structural features.Analysis of steroidal saponins in plant materials mainly utilizes classically and advances thin layer chromatography(TLC)on normal and reverses‑phase(high‑performance thin‑layer chromatography,densitometric TLC),gas chromatography,LC,UPLC,ultra‑high‑performance liquid chromatography(HPLC),supercritical fluid chromatography,and HPLC coupled to ultraviolet detector and diode array detector.HPLC coupled with MS and Nuclear magnetic resonance is used for online identification of separated saponins.The present review aims to furnish a comprehensive account of the recent advances in analytical methods of determination and medicinal applications of steroidal saponins.展开更多
Understanding the interactions of nanomaterials(NMs) with biomolecules, organelles, cells, and organic tissues at the nano-bio interface can offer important information for their uptake, distribution, translocation, m...Understanding the interactions of nanomaterials(NMs) with biomolecules, organelles, cells, and organic tissues at the nano-bio interface can offer important information for their uptake, distribution, translocation, metabolism and degradation in vitro and in vivo, which can help to precisely tune and design "smart" NMs for biomedical applications. However, probing the interactions at the nano-bio interface, which generally requires dedicated analytical methods and tools, is remarkably complicated due to the dynamically changed nature of the nano-bio interface. Because of the advantages of high spatial resolution, high sensitivity, excellent accuracy, low matrix effects and non-destructiveness, synchrotron radiation(SR)-based analytical techniques have become extremely valuable tools. Herein, we present a comprehensive overview of SR-based techniques for the visualized study of NMs at cellular and subcellular interfaces and their transformation in vitro; the exploration of biodistribution, translocation, metabolism and degradation of NMs in vivo; and clarification of the molecular mechanisms of NMs' reactions with biomolecules. Rapid development of advanced light source means that in situ, real-time analysis of NMs at the nano-bio interface will be achieved.展开更多
Diosgenin is a steroidal sapogenin found in plants such as Dioscorea nipponoca,Solanum incanum,Solanum xanthocarpum and Trigonella foenum graecum.Diosgenin,biologically active phytochemicals have been used for the tre...Diosgenin is a steroidal sapogenin found in plants such as Dioscorea nipponoca,Solanum incanum,Solanum xanthocarpum and Trigonella foenum graecum.Diosgenin,biologically active phytochemicals have been used for the treatment of various types of disorder such as leukemia,inflammation,hypercholesterolemia and cancer.It is also able to prevent bone loss to the same extent as that of oestrogen.It is a typical initial intermediate for synthesis of steroidal compounds,oral contraceptives and sex hormones.Dioscorea,Costus and Trigonella are mainly used for the production of diosgenin.On the basis of literature survey it divulges that diosgenin has very impressive pharmacological profile and could be used as a medicine for the treatment of different types of disorders in the future.Thus,the present work aims to provide collective information in concern with its pharmacological activity and phytoanalytical techniques.This review will be beneficial to researches for the development of an alternative method for the treatment of innumerable diseases from diosgenin.展开更多
With the air gap magnetic field distribution of surface mounted permanent magnet （PM） motors obtained using an analytical technique, the instantaneous electromagnetic torque and its corresponding components are inve...With the air gap magnetic field distribution of surface mounted permanent magnet （PM） motors obtained using an analytical technique, the instantaneous electromagnetic torque and its corresponding components are investigated with the Maxwell stress tensor method. Accurate results can easily be achieved using the proposed method without using the tedious finite element analysis （FEA）. In this paper, the electromagnetic torque of a surface mounted PM motor with two phases energized is decomposed into four torque components. This technique is useful not only for the design and optimization of the permanent magnet motor, but also for the choice of control strategy.展开更多
Corrosion is a pervasive phenomenon affecting materials across a multitude of scales,from the atomic to the macroscopic.This review paper presents a comprehensive examination of the methodologies employed in the analy...Corrosion is a pervasive phenomenon affecting materials across a multitude of scales,from the atomic to the macroscopic.This review paper presents a comprehensive examination of the methodologies employed in the analysis of magnesium corrosion,including electrochemical,non-electrochemical and analytical approaches,emphasizing the need for a diverse array of analytical tools to understand the complex interplay between corrosion,microstructure,and the dissolution mechanisms of magnesium alloys.The research showcases the utility of specific tools like SEM/EDS and SKPFM for targeted site analysis,while XPS and FTIR provide a broader perspective on specimen surfaces.The paper also discusses the value of in-situ analysis techniques,which allow for the real-time observation of corrosion processes,offering a dynamic view of the emergence and evolution of corrosion products.These in-situ methods stand in contrast to ex-situ analyses,which only permit post-experimental evaluation.By highlighting the capabilities of various analytical tools,from those that reveal surface layer details to those that probe deeper structures,and from those that detect primary elements to those that trace minute quantities of impurities,this study underscores the intricate nature of corrosion and the critical role of advanced analytical techniques in fostering a deeper understanding of material degradation.The findings advocate for the increased application of in-situ analysis in magnesium corrosion research,as it provides a more immediate and accurate depiction of corrosion dynamics,potentially leading to more effective corrosion prevention and control strategies.展开更多
Previous studies have demonstrated that intermediate-volatility and semivolatile organic compounds(I/SVOCs) are important precursors of secondary organic aerosols. Motor vehicles are important sources of atmospheric I...Previous studies have demonstrated that intermediate-volatility and semivolatile organic compounds(I/SVOCs) are important precursors of secondary organic aerosols. Motor vehicles are important sources of atmospheric I/SVOC emissions. In this paper, existing test methods for motor vehicle I/SVOCs are summarized, the advantages and disadvantages of various sampling methods and analytical techniques are compared, and the main factors influencing motor vehicle I/SVOC emissions are analyzed. The results show that the onboard test method compensates for the shortcomings of the bench test method, reflects the emission characteristics of I/SVOCs on actual roads, and has great application potential. The identification capability of traditional gas chromatography-mass spectrometry for I/SVOCs is very limited, whereas the high sensitivity and species identification capability of comprehensive two-dimensional gas chromatography provide obvious advantages in the study of I/SVOC samples. Motor vehicle I/SVOC emissions are influenced by many factors. The individual and combined effects of different factors remain uncertain, so the importance of control variables must be more notably emphasized in future studies of influencing factors. In this paper, a systematic review is offered that could serve as a valuable reference for future research on motor vehicle I/SVOC emissions and contribute to mitigating fine particulate matter pollution.展开更多
The quality of r-hGH has been appraised by various analytical techniques in-cluding SDS-PAGE, IEF. HPSEC, RP-HPLC, ELISA. Dot-immunobinding assay, DIG labeling DNAhybridization and bioassay The results shouwed that th...The quality of r-hGH has been appraised by various analytical techniques in-cluding SDS-PAGE, IEF. HPSEC, RP-HPLC, ELISA. Dot-immunobinding assay, DIG labeling DNAhybridization and bioassay The results shouwed that the quality of the domestic products of r-hGHreached the international level.展开更多
Design and modification of interfaces have been the main strategies in developing perovskite solar cells(PSCs). Among the interfacial treatments, dipole molecules have emerged as a practical approach to improve the ef...Design and modification of interfaces have been the main strategies in developing perovskite solar cells(PSCs). Among the interfacial treatments, dipole molecules have emerged as a practical approach to improve the efficiency and stability of PSCs due to their unique and versatile abilities to control the interfacial properties. Despite extensive applications in conventional semiconductors, working principles and design of interfacial dipoles in the performance/stability enhancement of PSCs are lacking an insightful elucidation. In this review, we first discuss the fundamental properties of electric dipoles and the specific roles of interfacial dipoles in PSCs. Then we systematically summarize the recent progress of dipole materials in several key interfaces to achieve efficient and stable PSCs. In addition to such discussions, we also dive into reliable analytical techniques to support the characterization of interfacial dipoles in PSCs. Finally, we highlight future directions and potential avenues for research in the development of dipolar materials through tailored molecular designs. Our review sheds light on the importance of continued efforts in this exciting emerging field, which holds great potential for the development of high-performance and stable PSCs as commercially demanded.展开更多
The widespread presence of per-and polyfluoroalkyl substances(PFAS)in the environment poses a serious threat due to their persistent nature and harmful effects on human health and ecosystems.In this context,there is a...The widespread presence of per-and polyfluoroalkyl substances(PFAS)in the environment poses a serious threat due to their persistent nature and harmful effects on human health and ecosystems.In this context,there is an imperative need for developing and improving methods to identify and eliminate these contaminants.Different detection techniques that are being used for PFAS detection are discussed.The details of detection mechanism of these techniques,their limitations and future areas of research for their optimization and improvement in detection efficiencies are also discussed in this review.Besides,this article provides a baseline for anticipating the advanced treatment technologies for PFAS in drinking water.We focus on the effectiveness of different removal techniques(physical,biological and chemical advancements)for eliminating various types of short and long chain PFAS.More so,the methods for the removal of PFAS are also explained with their limitations and future outlooks.Their pros and cons and limitations that need to be overcome and could be the potential future research.We included the recent literature and encompassed the information of PFAS related to guidelines,analytical techniques to determine PFAS and treatment or removal technologies.Conclusively,this study suggests that a combination of treatment methods will likely be necessary for effective PFAS remediation in water.展开更多
A new analytical method is proposed for the determination of heroin based on a sequential perturbation caused by trace amounts of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction between hydrogen peroxide and sodiu...A new analytical method is proposed for the determination of heroin based on a sequential perturbation caused by trace amounts of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium with the aid of a continuous-flow stirred tank reactor(CSTR). The method relies on the linear relationship between the change in oscillation period of the system and the concentration of heroin, with a detecting limit of 4.0×10^(-7) mol/L. The calibration curve fits a linear equation very well when the concentration of heroin is in the range of 2.0×10^(-6)_1.2×10^(-5) mol/L(r=0.9971). This method features good precision(RSD=0.98%). The influences of temperature, injection point, flow rate and reaction variables on the oscillation period were investigated in detail and a possible mechanism of the performance of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction system is also discussed. The proposed method opens a new avenue for the determination of heroin.展开更多
The optimization of the Earth-moon trajectory using solar electric propulsion is presented. A feasible method is proposed to optimize the transfer trajectory starting from a low Earth circular orbit （500 km altitude...The optimization of the Earth-moon trajectory using solar electric propulsion is presented. A feasible method is proposed to optimize the transfer trajectory starting from a low Earth circular orbit （500 km altitude） to a low lunar circular orbit （200 km altitude）. Due to the use of low-thrust solar electric propulsion, the entire transfer trajectory consists of hundreds or even thousands of orbital revolutions around the Earth and the moon. The Earth-orbit ascending （from low Earth orbit to high Earth orbit） and lunar descending （from high lunar orbit to low lunar orbit） trajectories in the presence of J2 perturbations and shadowing effect are computed by an analytic orbital averaging technique. A direct/indirect method is used to optimize the control steering for the trans-lunar trajectory segment, a segment from a high Earth orbit to a high lunar orbit, with a fixed thrust-coast-thrust engine sequence. For the trans-lunar trajectory segment, the equations of motion are expressed in the inertial coordinates about the Earth and the moon using a set of nonsingular equinoctial elements inclusive of the gravitational forces of the sun, the Earth, and the moon. By way of the analytic orbital averaging technique and the direct/indirect method, the Earth-moon transfer problem is converted to a parameter optimization problem, and the entire transfer trajectory is formulated and optimized in the form of a single nonlinear optimization problem with a small number of variables and constraints. Finally, an example of an Earth-moon transfer trajectory using solar electric propulsion is demonstrated.展开更多
Object correlation and maneuver detection are persistent problems in space surveillance and maintenance of a space object catalog. We integrate these two prob- lems into one interrelated problem, and consider them sim...Object correlation and maneuver detection are persistent problems in space surveillance and maintenance of a space object catalog. We integrate these two prob- lems into one interrelated problem, and consider them simultaneously under a sce- nario where space objects only perform a single in-track orbital maneuver during the time intervals between observations. We mathematically formulate this integrated sce- nario as a maximum a posteriori （MAP） estimation. In this work, we propose a novel approach to solve the MAP estimation. More precisely, the corresponding posterior probability of an orbital maneuver and a joint association event can be approximated by the Joint Probabilistic Data Association （JPDA） algorithm. Subsequently, the ma- neuvering parameters are estimated by optimally solving the constrained non-linear least squares iterative process based on the second-order cone programming （SOCP） algorithm. The desired solution is derived according to the MAP criterions. The per- formance and advantages of the proposed approach have been shown by both theoret- ical analysis and simulation results. We hope that our work will stimulate future work on space surveillance and maintenance of a space object catalog.展开更多
Lunar Penetrating Radar （LPR） onboard the rover that is part of the Chang＇e-3 （CE-3） mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness o...Lunar Penetrating Radar （LPR） onboard the rover that is part of the Chang＇e-3 （CE-3） mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetra- tion depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm.展开更多
This study deals with the features of the mass and heat transport mechanism by adopting a modified version of Fourier and Fick’s model known as the CattaneoChristov double diffusive theory.The time-dependent magnetoh...This study deals with the features of the mass and heat transport mechanism by adopting a modified version of Fourier and Fick’s model known as the CattaneoChristov double diffusive theory.The time-dependent magnetohydrodynamic(MHD)flow of the Eyring-Powell liquid across an oscillatory stretchable curved sheet in the presence of Fourier and Fick’s model is investigated.The acquired set of flow equations is transformed into the form of nonlinear partial differential equations(PDEs)by applying appropriate similarity variables.A convergent series solution to the developed nonlinear equations is accomplished with the help of an analytical approach,i.e.,the homotopy analysis method(HAM).The consequences of diverse parameters,including the dimensionless EyringPowell liquid parameter,the radius of curvature,the Schmidt/Prandtl numbers,the ratio of the oscillatory frequency of the sheet to its stretchable rate constant,the mass and thermal relaxation variables involved in the flow,and the heat and mass properties,are displayed through graphs and tables.It is noted from this study that the amplitude of the pressure distribution rises for the high parametric values of the Eyring-Powell parameter.展开更多
In this paper, the basic ideas of a new analytic technique, namely the Homotopy Analysis Method (HAM), are described. Different from perturbation methods, the validity of the HAM is independent on whether or not there...In this paper, the basic ideas of a new analytic technique, namely the Homotopy Analysis Method (HAM), are described. Different from perturbation methods, the validity of the HAM is independent on whether or not there exist small parameters in considered nonlinear equations. Therefore, it provides us with a powerful analytic tool for strongly nonlinear problems. A typical nonlinear problem is used as an example to verify the validity and the great potential of the HAM.展开更多
The comparative analysis of modem mathematical models for 3D problems in electron optics is presented. The new approach to solve the electron optics problems in three dimensions is presented. It is based on the princi...The comparative analysis of modem mathematical models for 3D problems in electron optics is presented. The new approach to solve the electron optics problems in three dimensions is presented. It is based on the principal ray method suggested by G. Grinberg in 1948. That perspective approach was not realized before for full three-dimensional electron optic systems, probably because of the complexity of its mathematical apparatus. We describe the analytical technique of the BEM （boundary element method） for the field evaluation, and 3rd order aberration expansion for the trajectory analysis. The first version of such computer code ＂OPTICS-3＂ and some results of numerical simulations with this code were presented.展开更多
文摘Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization.
基金financialy supported by National Key R&D Program of China(2022YFB2402600)the National Natural Science Foundation of China(22279166)+1 种基金the Research Start-up Funds from Sun Yat-Sen University(200306)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(22qntd0101 and 22dfx01)
文摘Pseudocapacitive materials that store charges via reversible surface or near-surface faradaic reactions are capable of overcoming the capacity limitations of electrical double-layer capacitors.Revealing the structure–activity relationship between the microstructural features of pseudocapacitive materials and their electrochemical performance on the atomic scale is the key to build high-performance capacitor-type devices containing ideal pseudocapacitance effect.Currently,the high brightness(flux),and spectral and coherent nature of synchrotron X-ray analytical techniques make it a powerful tool for probing the structure–property relationship of pseudocapacitive materials.Herein,we report a comprehensive and systematic review of four typical characterization techniques(synchrotron X-ray diffraction,pair distribution function[PDF]analysis,soft X-ray absorption spectroscopy,and hard X-ray absorption spectroscopy)for the study of pseudocapacitance mechanisms.In addition,we offered significant insights for understanding and identifying pseudocapacitance mechanisms(surface redox pseudocapacitance,intercalation pseudocapacitance,and the extrinsic pseudocapacitance phenomenon in battery materials)by combining in situ hard XAS and electrochemical analyses.Finally,a perspective for further depth of understanding into the pseudocapacitance mechanism using synchrotron X-ray analytical techniques is proposed.
文摘There are many well-known analytical methods for determination of iron（Ⅱ） and iron（Ⅲ）. Among these methods： Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometric methods. In present study, two batch spectrophotometric, atomic absorption spectrometric and biolabo kit methods have been used for determination of iron（Ⅱ）, iron（Ⅲ） and total iron. The present methods have the advantages of high sensitivity, low cost reagent, low operation cost, simplicity, speed and their applications for determination of iron（Ⅱ） and iron（Ⅲ） in some serum samples of normal human and fl-thalasemia patients in Erbil city. For the first time especially in Erbil city attempts were made to use zero, first and second derivative spectra to identify the serum samples of some β-thallasemia patients from the normal human serum samples due to the appearance and resolution of peaks in both cases.
文摘The World Health Organisation reported that over 20 % of the global disease burden and deaths are caused by environmental factors such as air and dust pollution. Legacy organic pollutants (LOPs) and emerging organic pollutants (EOPs) are among the biggest contributors to this burden. Herein we reviewed literature published for the period 2000–2023 on selected LOPs and EOPs in indoor dust and outdoor air in Africa to understand the occurrence, associated human health risks and common analytical techniques used to identify and quantify these contaminants. The findings revealed generally lower contamination levels for most pollutants than that in most regions outside Africa except for PCBs in outdoor air and OCPs in indoor settled dust. Apart from a few studies for polychlorinated biphenyls (PCBs), most studies reported hazard index (HI) values less than 1 for outdoor air and indoor dust exposure, which suggested negligible non-carcinogenic risks in children and adults. Gas Chromatography and mass spectrometry were the most frequently used analytical techniques for both air and dust probably due to their sensitivity and selectivity in detecting chemical traces at the pg m^(−3) and ng g^(−1) levels. Although the current contamination levels are generally low, their synergistic and cumulative effects may in the long run affect the environment and human health. There is also a paucity of data on most contaminants, especially for PCNs, and PFASs in both outdoor air and dust. Coordinated efforts are needed to limit the trade, importation, and disposal of products containing LOPs and EOPs in Africa.
文摘The plant is a rich repository of useful secondary metabolites with profound medicinal potential.Saponins,one type of bioactive compound,are amphitheatric glycosides with one and more hydrophilic sugar and hydrophobic steroidal and terpenoid part.The former is known as steroidal saponin,and the latter is called terpenoid saponins.Steroidal saponin is mostly distributed among monocotyledon families such as Asparagaceae,Amaryllidaceae,Dioscoreaceae,Smilacaceae,and Liliaceae.Even though it is unusual,it could also be detected to some extent by dicotyledonous angiosperms,such as Plantaginaceae,Zygophyllaceae,Fabaceae,Asteraceae,and Solanaceae.It exhibits diverse pharmacological ability including antimicrobic,anti‑inflammatory,cAMP phosphodiesterase inhibitory,antiadipogenic,bactericide,cardioprotective,antitumor,antidiabetic,cytotoxic activity,antifungal,antiviral,antioxidant,and hepatoprotective.Steroidal saponin timosaponin AIII from Anemarrhena asphodeloides has been found to possess antitumor activity.Diosgenin,another steroidal sapogenin,has the potential of preventing neurological diseases by affecting different signaling pathways,increasing bone formation,and increasing antithrombotic activity.Spicatoside A from Liriope platyphylla possesses anti‑inflammatory,antiasthma,and antiosteoclastogenic activities.TTB2 from Trillium tschonoskii exhibits anticancer potential.The cell cycle arrest and ROS‑dependent autophagy are induced by polyphyllin I.These diverse biological activities of steroidal saponins are attributed to the variability of their structural features.Analysis of steroidal saponins in plant materials mainly utilizes classically and advances thin layer chromatography(TLC)on normal and reverses‑phase(high‑performance thin‑layer chromatography,densitometric TLC),gas chromatography,LC,UPLC,ultra‑high‑performance liquid chromatography(HPLC),supercritical fluid chromatography,and HPLC coupled to ultraviolet detector and diode array detector.HPLC coupled with MS and Nuclear magnetic resonance is used for online identification of separated saponins.The present review aims to furnish a comprehensive account of the recent advances in analytical methods of determination and medicinal applications of steroidal saponins.
基金supported by the National Basic Research Program of China(2011CB933403)the State Key Program of National Natural Science Foundation of China(U1432245)the National Natural Science Foundation of China(11475195,11275214,11375211)
文摘Understanding the interactions of nanomaterials(NMs) with biomolecules, organelles, cells, and organic tissues at the nano-bio interface can offer important information for their uptake, distribution, translocation, metabolism and degradation in vitro and in vivo, which can help to precisely tune and design "smart" NMs for biomedical applications. However, probing the interactions at the nano-bio interface, which generally requires dedicated analytical methods and tools, is remarkably complicated due to the dynamically changed nature of the nano-bio interface. Because of the advantages of high spatial resolution, high sensitivity, excellent accuracy, low matrix effects and non-destructiveness, synchrotron radiation(SR)-based analytical techniques have become extremely valuable tools. Herein, we present a comprehensive overview of SR-based techniques for the visualized study of NMs at cellular and subcellular interfaces and their transformation in vitro; the exploration of biodistribution, translocation, metabolism and degradation of NMs in vivo; and clarification of the molecular mechanisms of NMs' reactions with biomolecules. Rapid development of advanced light source means that in situ, real-time analysis of NMs at the nano-bio interface will be achieved.
文摘Diosgenin is a steroidal sapogenin found in plants such as Dioscorea nipponoca,Solanum incanum,Solanum xanthocarpum and Trigonella foenum graecum.Diosgenin,biologically active phytochemicals have been used for the treatment of various types of disorder such as leukemia,inflammation,hypercholesterolemia and cancer.It is also able to prevent bone loss to the same extent as that of oestrogen.It is a typical initial intermediate for synthesis of steroidal compounds,oral contraceptives and sex hormones.Dioscorea,Costus and Trigonella are mainly used for the production of diosgenin.On the basis of literature survey it divulges that diosgenin has very impressive pharmacological profile and could be used as a medicine for the treatment of different types of disorders in the future.Thus,the present work aims to provide collective information in concern with its pharmacological activity and phytoanalytical techniques.This review will be beneficial to researches for the development of an alternative method for the treatment of innumerable diseases from diosgenin.
基金Project supported by the Science Foundation of Shanghai Municipal Commission of Education （Grant No.04AB30）
文摘With the air gap magnetic field distribution of surface mounted permanent magnet （PM） motors obtained using an analytical technique, the instantaneous electromagnetic torque and its corresponding components are investigated with the Maxwell stress tensor method. Accurate results can easily be achieved using the proposed method without using the tedious finite element analysis （FEA）. In this paper, the electromagnetic torque of a surface mounted PM motor with two phases energized is decomposed into four torque components. This technique is useful not only for the design and optimization of the permanent magnet motor, but also for the choice of control strategy.
文摘Corrosion is a pervasive phenomenon affecting materials across a multitude of scales,from the atomic to the macroscopic.This review paper presents a comprehensive examination of the methodologies employed in the analysis of magnesium corrosion,including electrochemical,non-electrochemical and analytical approaches,emphasizing the need for a diverse array of analytical tools to understand the complex interplay between corrosion,microstructure,and the dissolution mechanisms of magnesium alloys.The research showcases the utility of specific tools like SEM/EDS and SKPFM for targeted site analysis,while XPS and FTIR provide a broader perspective on specimen surfaces.The paper also discusses the value of in-situ analysis techniques,which allow for the real-time observation of corrosion processes,offering a dynamic view of the emergence and evolution of corrosion products.These in-situ methods stand in contrast to ex-situ analyses,which only permit post-experimental evaluation.By highlighting the capabilities of various analytical tools,from those that reveal surface layer details to those that probe deeper structures,and from those that detect primary elements to those that trace minute quantities of impurities,this study underscores the intricate nature of corrosion and the critical role of advanced analytical techniques in fostering a deeper understanding of material degradation.The findings advocate for the increased application of in-situ analysis in magnesium corrosion research,as it provides a more immediate and accurate depiction of corrosion dynamics,potentially leading to more effective corrosion prevention and control strategies.
基金supported by the Natural Science Foundation of Beijing Municipality (No.8222041)the National Key Research and Development Program of China (No.2022YFC3700604)。
文摘Previous studies have demonstrated that intermediate-volatility and semivolatile organic compounds(I/SVOCs) are important precursors of secondary organic aerosols. Motor vehicles are important sources of atmospheric I/SVOC emissions. In this paper, existing test methods for motor vehicle I/SVOCs are summarized, the advantages and disadvantages of various sampling methods and analytical techniques are compared, and the main factors influencing motor vehicle I/SVOC emissions are analyzed. The results show that the onboard test method compensates for the shortcomings of the bench test method, reflects the emission characteristics of I/SVOCs on actual roads, and has great application potential. The identification capability of traditional gas chromatography-mass spectrometry for I/SVOCs is very limited, whereas the high sensitivity and species identification capability of comprehensive two-dimensional gas chromatography provide obvious advantages in the study of I/SVOC samples. Motor vehicle I/SVOC emissions are influenced by many factors. The individual and combined effects of different factors remain uncertain, so the importance of control variables must be more notably emphasized in future studies of influencing factors. In this paper, a systematic review is offered that could serve as a valuable reference for future research on motor vehicle I/SVOC emissions and contribute to mitigating fine particulate matter pollution.
文摘The quality of r-hGH has been appraised by various analytical techniques in-cluding SDS-PAGE, IEF. HPSEC, RP-HPLC, ELISA. Dot-immunobinding assay, DIG labeling DNAhybridization and bioassay The results shouwed that the quality of the domestic products of r-hGHreached the international level.
基金supported by National Key Research and Development Program of China (2022YFB4200301)the Fundamental Research Funds for the Central Universities (ZYGX2022YGRH010)+1 种基金the National Natural Science Foundation of China (62274026, 52202216)Natural Science Foundation of Sichuan Province (2023NSFSC0962, 2022NSFSC1797)。
文摘Design and modification of interfaces have been the main strategies in developing perovskite solar cells(PSCs). Among the interfacial treatments, dipole molecules have emerged as a practical approach to improve the efficiency and stability of PSCs due to their unique and versatile abilities to control the interfacial properties. Despite extensive applications in conventional semiconductors, working principles and design of interfacial dipoles in the performance/stability enhancement of PSCs are lacking an insightful elucidation. In this review, we first discuss the fundamental properties of electric dipoles and the specific roles of interfacial dipoles in PSCs. Then we systematically summarize the recent progress of dipole materials in several key interfaces to achieve efficient and stable PSCs. In addition to such discussions, we also dive into reliable analytical techniques to support the characterization of interfacial dipoles in PSCs. Finally, we highlight future directions and potential avenues for research in the development of dipolar materials through tailored molecular designs. Our review sheds light on the importance of continued efforts in this exciting emerging field, which holds great potential for the development of high-performance and stable PSCs as commercially demanded.
文摘The widespread presence of per-and polyfluoroalkyl substances(PFAS)in the environment poses a serious threat due to their persistent nature and harmful effects on human health and ecosystems.In this context,there is an imperative need for developing and improving methods to identify and eliminate these contaminants.Different detection techniques that are being used for PFAS detection are discussed.The details of detection mechanism of these techniques,their limitations and future areas of research for their optimization and improvement in detection efficiencies are also discussed in this review.Besides,this article provides a baseline for anticipating the advanced treatment technologies for PFAS in drinking water.We focus on the effectiveness of different removal techniques(physical,biological and chemical advancements)for eliminating various types of short and long chain PFAS.More so,the methods for the removal of PFAS are also explained with their limitations and future outlooks.Their pros and cons and limitations that need to be overcome and could be the potential future research.We included the recent literature and encompassed the information of PFAS related to guidelines,analytical techniques to determine PFAS and treatment or removal technologies.Conclusively,this study suggests that a combination of treatment methods will likely be necessary for effective PFAS remediation in water.
基金Supported by the Project of International Cooperation between China and U kraine(No.0 4 3- 0 5 ) and the Project ofKJCXGC- 0 1Northwest Norm al U niversityChina
文摘A new analytical method is proposed for the determination of heroin based on a sequential perturbation caused by trace amounts of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction between hydrogen peroxide and sodium thiocyanate in an alkaline medium with the aid of a continuous-flow stirred tank reactor(CSTR). The method relies on the linear relationship between the change in oscillation period of the system and the concentration of heroin, with a detecting limit of 4.0×10^(-7) mol/L. The calibration curve fits a linear equation very well when the concentration of heroin is in the range of 2.0×10^(-6)_1.2×10^(-5) mol/L(r=0.9971). This method features good precision(RSD=0.98%). The influences of temperature, injection point, flow rate and reaction variables on the oscillation period were investigated in detail and a possible mechanism of the performance of heroin in the Cu(Ⅱ)-catalyzed oscillating reaction system is also discussed. The proposed method opens a new avenue for the determination of heroin.
基金National Natural Science Foundation of China (10603005)
文摘The optimization of the Earth-moon trajectory using solar electric propulsion is presented. A feasible method is proposed to optimize the transfer trajectory starting from a low Earth circular orbit （500 km altitude） to a low lunar circular orbit （200 km altitude）. Due to the use of low-thrust solar electric propulsion, the entire transfer trajectory consists of hundreds or even thousands of orbital revolutions around the Earth and the moon. The Earth-orbit ascending （from low Earth orbit to high Earth orbit） and lunar descending （from high lunar orbit to low lunar orbit） trajectories in the presence of J2 perturbations and shadowing effect are computed by an analytic orbital averaging technique. A direct/indirect method is used to optimize the control steering for the trans-lunar trajectory segment, a segment from a high Earth orbit to a high lunar orbit, with a fixed thrust-coast-thrust engine sequence. For the trans-lunar trajectory segment, the equations of motion are expressed in the inertial coordinates about the Earth and the moon using a set of nonsingular equinoctial elements inclusive of the gravitational forces of the sun, the Earth, and the moon. By way of the analytic orbital averaging technique and the direct/indirect method, the Earth-moon transfer problem is converted to a parameter optimization problem, and the entire transfer trajectory is formulated and optimized in the form of a single nonlinear optimization problem with a small number of variables and constraints. Finally, an example of an Earth-moon transfer trajectory using solar electric propulsion is demonstrated.
文摘Object correlation and maneuver detection are persistent problems in space surveillance and maintenance of a space object catalog. We integrate these two prob- lems into one interrelated problem, and consider them simultaneously under a sce- nario where space objects only perform a single in-track orbital maneuver during the time intervals between observations. We mathematically formulate this integrated sce- nario as a maximum a posteriori （MAP） estimation. In this work, we propose a novel approach to solve the MAP estimation. More precisely, the corresponding posterior probability of an orbital maneuver and a joint association event can be approximated by the Joint Probabilistic Data Association （JPDA） algorithm. Subsequently, the ma- neuvering parameters are estimated by optimally solving the constrained non-linear least squares iterative process based on the second-order cone programming （SOCP） algorithm. The desired solution is derived according to the MAP criterions. The per- formance and advantages of the proposed approach have been shown by both theoret- ical analysis and simulation results. We hope that our work will stimulate future work on space surveillance and maintenance of a space object catalog.
基金Supported by the National Natural Science Foundation of China
文摘Lunar Penetrating Radar （LPR） onboard the rover that is part of the Chang＇e-3 （CE-3） mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetra- tion depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm.
文摘This study deals with the features of the mass and heat transport mechanism by adopting a modified version of Fourier and Fick’s model known as the CattaneoChristov double diffusive theory.The time-dependent magnetohydrodynamic(MHD)flow of the Eyring-Powell liquid across an oscillatory stretchable curved sheet in the presence of Fourier and Fick’s model is investigated.The acquired set of flow equations is transformed into the form of nonlinear partial differential equations(PDEs)by applying appropriate similarity variables.A convergent series solution to the developed nonlinear equations is accomplished with the help of an analytical approach,i.e.,the homotopy analysis method(HAM).The consequences of diverse parameters,including the dimensionless EyringPowell liquid parameter,the radius of curvature,the Schmidt/Prandtl numbers,the ratio of the oscillatory frequency of the sheet to its stretchable rate constant,the mass and thermal relaxation variables involved in the flow,and the heat and mass properties,are displayed through graphs and tables.It is noted from this study that the amplitude of the pressure distribution rises for the high parametric values of the Eyring-Powell parameter.
文摘In this paper, the basic ideas of a new analytic technique, namely the Homotopy Analysis Method (HAM), are described. Different from perturbation methods, the validity of the HAM is independent on whether or not there exist small parameters in considered nonlinear equations. Therefore, it provides us with a powerful analytic tool for strongly nonlinear problems. A typical nonlinear problem is used as an example to verify the validity and the great potential of the HAM.
文摘The comparative analysis of modem mathematical models for 3D problems in electron optics is presented. The new approach to solve the electron optics problems in three dimensions is presented. It is based on the principal ray method suggested by G. Grinberg in 1948. That perspective approach was not realized before for full three-dimensional electron optic systems, probably because of the complexity of its mathematical apparatus. We describe the analytical technique of the BEM （boundary element method） for the field evaluation, and 3rd order aberration expansion for the trajectory analysis. The first version of such computer code ＂OPTICS-3＂ and some results of numerical simulations with this code were presented.
