Low-voltage direct current(DC)microgrids have recently emerged as a promising and viable alternative to traditional alternating cur-rent(AC)microgrids,offering numerous advantages.Consequently,researchers are explorin...Low-voltage direct current(DC)microgrids have recently emerged as a promising and viable alternative to traditional alternating cur-rent(AC)microgrids,offering numerous advantages.Consequently,researchers are exploring the potential of DC microgrids across var-ious configurations.However,despite the sustainability and accuracy offered by DC microgrids,they pose various challenges when integrated into modern power distribution systems.Among these challenges,fault diagnosis holds significant importance.Rapid fault detection in DC microgrids is essential to maintain stability and ensure an uninterrupted power supply to critical loads.A primary chal-lenge is the lack of standards and guidelines for the protection and safety of DC microgrids,including fault detection,location,and clear-ing procedures for both grid-connected and islanded modes.In response,this study presents a brief overview of various approaches for protecting DC microgrids.展开更多
This paper systematically categorizes the primary composition of star anise(Illicium verum),including volatile oils,flavonoids,phenolic acids,and sesquiterpene lactones,and further analyzes the pharmacological activit...This paper systematically categorizes the primary composition of star anise(Illicium verum),including volatile oils,flavonoids,phenolic acids,and sesquiterpene lactones,and further analyzes the pharmacological activities,such as antibacterial,analgesic,anti-inflammatory,and antioxidant effects.Additionally,it summarizes key aspects of extraction techniques,analytical methods,and fresh material processing technologies.The objective is to provide a robust foundation for enhancing research methods and technological standards related to star anise,thereby improving resource utilization efficiency and facilitating its industrial applications.展开更多
Based on the dual source cumulative rotation technique in the time-domain proposed by Zeng and MacBeth(1993),a new algebraic processing technique for extracting shear-wave splitting parameters from multi-component V...Based on the dual source cumulative rotation technique in the time-domain proposed by Zeng and MacBeth(1993),a new algebraic processing technique for extracting shear-wave splitting parameters from multi-component VSP data in frequency-dependent medium has been developed.By using this dual source cumulative rotation technique in the frequency-domain(DCTF),anisotropic parameters,including polarization direction of the shear-waves and timedelay between the fast and slow shear-waves,can be estimated for each frequency component in the frequency domain.It avoids the possible error which comes from using a narrow-band filter in the current commonly used method.By using synthetic seismograms,the feasibility and validity of the technique was tested and a comparison with the currently used method was also given.The results demonstrate that the shear-wave splitting parameters frequency dependence can be extracted directly from four-component seismic data using the DCTF.In the presence of larger scale fractures,substantial frequency dependence would be found in the seismic frequency range,which implies that dispersion would occur at seismic frequencies.Our study shows that shear-wave anisotropy decreases as frequency increases.展开更多
This study was conducted to investigate the recipe and process of instant pickle by multiple steps with dry daylily as a raw material, and an orthogonal test was adopted to obtain the optimal recipe and process. The p...This study was conducted to investigate the recipe and process of instant pickle by multiple steps with dry daylily as a raw material, and an orthogonal test was adopted to obtain the optimal recipe and process. The pickling process of the instant flavored daylily was conducted at an optimal crisp-keeping Ca Cl2 concentration at 0.050%, cooking time of 5 min, pickling time of 6 h and a salt concentration of 4%. The effects of various factors on product taste were in order of salt concentrationcooking timepickling timeCa Cl2 concentration.The obtained product has the characteristics of strong fragrance, crisp delicious taste and unique flavor with stomachic effect.展开更多
Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This r...Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This review mainly summarized the research reports on short process forming techniques for brazing and soldering materials.Firstly,the traditional process and its shortcomings were presented.Secondly,the latest research of short process forming technologies,such as continuous casting technique,atomization powder technique,solder ball forming technique,and rapid solidification technique,was summarized,and the traditional forming performance of several brazing and soldering materials was introduced.Finally,the current restrictions and research trends of short process forming technique for brazing and solder materials were put forward,providing theoretical guidance and reference for related research and technique development in brazing and soldering field.展开更多
In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers a...In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers as they directly affect the regular service for the users.Therefore,monitoring the health status of pavement before irreversible damage occurs is essential for timely maintenance,which in turn ensures public transportation safety.Many pavement damages can be detected and analyzed by monitoring the structure dynamic responses and evaluating road surface conditions.Advanced technologies can be employed for the collection and analysis of such data,including various intrusive sensing techniques,image processing techniques,and machine learning methods.This review summarizes the state-ofthe-art of these three technologies in pavement engineering in recent years and suggests possible developments for future pavement monitoring and analysis based on these approaches.展开更多
[Objectives]To optimize the processing technology of baked Rheum tanguticum carbon.[Methods]Firstly,the baking temperature and baking time were investigated by single factor,and the content of 5-hydroxymethylfurfural(...[Objectives]To optimize the processing technology of baked Rheum tanguticum carbon.[Methods]Firstly,the baking temperature and baking time were investigated by single factor,and the content of 5-hydroxymethylfurfural(5-HMF)was determined by HPLC.The main influencing factors of baking effect were baking temperature,baking time and tablet specifications.The L 9(34)orthogonal design experiment was carried out to optimize the processing technique of R.tanguticum carbon.[Results]The optimum processing technique was as follows:small-sized tablets,controlled oven baking temperature at(210±2)℃,and baking time of 20 min.[Conclusions]The optimum processing technique of R.tanguticum carbon is reasonable and feasible.Thus,this experiment can provide a certain reference for processing method and quality control of R.tanguticum carbon.展开更多
Phosphatidylserine(PS)is the part of cell structure in the body and has many beneficial functions especially in brain-related aging diseases.Although daily foods can provide PS to human body,the amount is very limited...Phosphatidylserine(PS)is the part of cell structure in the body and has many beneficial functions especially in brain-related aging diseases.Although daily foods can provide PS to human body,the amount is very limited due to its poverty in most foods.To overcome the issue,numerous studies based on PS have been reported to develop PS-related supplements.In this review,PS was comprehensively and critically reviewed from the view of resources,functions,processing techniques,patents,and prospects.For resources,animal,plant,and microorganism origins were all covered with their differences in composition profiles.For functions,benefits regarding memory,cognitive enhancement,exercise performance,reducing Alzheimer’s disease,and attention-deficit hyperactivity disorder symptoms were covered as well as the functional differences among animal-,plant-,and microorganism-based PS-related supplements.For processing techniques,traditional extracting methods from animal,plant,and microorganism tissues were comparatively discussed with enzymatic synthesis based on different reaction systems.Finally,patents of PS-related supplements were evaluated as well as their applications.This review could provide scientific and valuable support for PS industry.展开更多
[Objectives]Effects of different processing techniques on the total alkaloid content in Toddalia asiatica Lam.were investigated by ultraviolet spectrophotometry.[Methods]T.asiatica was processed by the water washing m...[Objectives]Effects of different processing techniques on the total alkaloid content in Toddalia asiatica Lam.were investigated by ultraviolet spectrophotometry.[Methods]T.asiatica was processed by the water washing method,water boiling method,water steaming method,wine steaming method and wine processing method,and the total alkaloid content was determined by ultraviolet spectrophotometry.[Results]Different processing methods can affect the total alkaloid content in the medicinal materials.Among them,the water steaming method and the wine processing method can increase the total alkaloid content of the medicinal materials,and the degree of improvement was higher in the water steaming method;and the water boiling method,water washing method and wine steaming method can reduce the total alkaloid content of the materials,and showed a reduction order of water boiling method>water washing method>wine steaming method.[Conclusions]The water steaming method and the wine processing method can increase the total alkaloid content in T.asiatica,and the water boiling method,water washing method and wine steaming method can reduce the total alkaloid content of the medicinal material.展开更多
This paper relates to the fabrication of aluminium matrix composites with various amounts of Al 2O 3 fiber and SiC whiskers by rheocasting, powder metallurgy process and liquid metal infiltration process. To analy...This paper relates to the fabrication of aluminium matrix composites with various amounts of Al 2O 3 fiber and SiC whiskers by rheocasting, powder metallurgy process and liquid metal infiltration process. To analyze wetting characteristics, the cross sections of composites are examined by scanning electron microscopy(SEM). The bending tests and microhardness tests are performed to evaluate mechanical properties of composites. The results show that the composites produced by liquid metal infiltration give better properties than those produced by rheocasting or powder metallurgy process, primarily due to the decrease of porosity and reinforcement cluster. For liquid metal infiltration composites, a good adhesion between the fiber and matrix is found. Three points bending test results show that there is an increase in flexural modulus with reinforcement contents. In addition, a series of microhardness tests are conducted to determine the effect of heat treatment on the mechanical property of Al 2O 3/Al composites.展开更多
The rapid developing of the fourth generation(4G)wireless communications has aroused tremendous demands for high speed data transmission due to the dissemination of various types of the intelligent user terminals as w...The rapid developing of the fourth generation(4G)wireless communications has aroused tremendous demands for high speed data transmission due to the dissemination of various types of the intelligent user terminals as well as the wireless multi-media services.It is predicted that the network throughput will increase展开更多
As a production quality index of hematite grinding process,particle size(PS)is hard to be measured in real time.To achieve the PS estimation,this paper proposes a novel data driven model of PS using stochastic configu...As a production quality index of hematite grinding process,particle size(PS)is hard to be measured in real time.To achieve the PS estimation,this paper proposes a novel data driven model of PS using stochastic configuration network(SCN)with robust technique,namely,robust SCN(RSCN).Firstly,this paper proves the universal approximation property of RSCN with weighted least squares technique.Secondly,three robust algorithms are presented by employing M-estimation with Huber loss function,M-estimation with interquartile range(IQR)and nonparametric kernel density estimation(NKDE)function respectively to set the penalty weight.Comparison experiments are first carried out based on the UCI standard data sets to verify the effectiveness of these methods,and then the data-driven PS model based on the robust algorithms are established and verified.Experimental results show that the RSCN has an excellent performance for the PS estimation.展开更多
The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling diges...The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery.展开更多
1.Introduction Various geological phenomena on the surface and in the interior of the Earth,as well as their associated physical and chemical pro-cesses,are closely correlated with the action of in situ rock stress[1-...1.Introduction Various geological phenomena on the surface and in the interior of the Earth,as well as their associated physical and chemical pro-cesses,are closely correlated with the action of in situ rock stress[1-5].Understanding the rock stress state at great depths is not only an indispensable foundation for solving scientific problems associated with geology,geophysics,and geodynamics-such as plate-driving mechanisms,the earth’s energy equilibrium,earth-quake mechanisms,and tectonic activities-but also a necessary prerequisite for the evaluation,exploitation,and disposal of deep energy and resources,such as coal and metal minerals.Due to the complexity and uncertainty of the origin of in situ rock stress,it is a difficult quantity to evaluate,in comparison with other rock properties.Currently,reliable information on the stress state in a region can only be determined through field stress measurement.Therefore,a variety of stress measurement techniques have been developed and applied worldwide to provide information on crus-tal contemporary stress at specific depth ranges[6].展开更多
Network maintenance strategy selection is a multi-objective decision making topic. It mostly depends on the uncertainty and fuzziness of decision makers and conditions. In this paper, based on analytic hierarchy proce...Network maintenance strategy selection is a multi-objective decision making topic. It mostly depends on the uncertainty and fuzziness of decision makers and conditions. In this paper, based on analytic hierarchy process(AHP) and technique for order preference by similarity to ideal solution(TOPSIS), TOPSIS partial order method is proposed to choose the optimal maintenance strategy. This method uses AHP to determine the weights of evaluation indexes. The optimal maintenance strategy choice is given as an example to demonstrate the effectiveness of the method.展开更多
Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic...Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.展开更多
The increasing demand for high-resolution solar observations has driven the development of advanced data processing and enhancement techniques for ground-based solar telescopes.This study focuses on developing a pytho...The increasing demand for high-resolution solar observations has driven the development of advanced data processing and enhancement techniques for ground-based solar telescopes.This study focuses on developing a python-based package(GT-scopy)for data processing and enhancing for giant solar telescopes,with application to the 1.6 m Goode Solar Telescope(GST)at Big Bear Solar Observatory.The objective is to develop a modern data processing software for refining existing data acquisition,processing,and enhancement methodologies to achieve atmospheric effect removal and accurate alignment at the sub-pixel level,particularly within the processing levels 1.0-1.5.In this research,we implemented an integrated and comprehensive data processing procedure that includes image de-rotation,zone-of-interest selection,coarse alignment,correction for atmospheric distortions,and fine alignment at the sub-pixel level with an advanced algorithm.The results demonstrate a significant improvement in image quality,with enhanced visibility of fine solar structures both in sunspots and quiet-Sun regions.The enhanced data processing package developed in this study significantly improves the utility of data obtained from the GST,paving the way for more precise solar research and contributing to a better understanding of solar dynamics.This package can be adapted for other ground-based solar telescopes,such as the Daniel K.Inouye Solar Telescope(DKIST),the European Solar Telescope(EST),and the 8 m Chinese Giant Solar Telescope,potentially benefiting the broader solar physics community.展开更多
This paper provides a comprehensive introduction to the mini-Si Tian Real-time Image Processing pipeline(STRIP)and evaluates its operational performance.The STRIP pipeline is specifically designed for real-time alert ...This paper provides a comprehensive introduction to the mini-Si Tian Real-time Image Processing pipeline(STRIP)and evaluates its operational performance.The STRIP pipeline is specifically designed for real-time alert triggering and light curve generation for transient sources.By applying the STRIP pipeline to both simulated and real observational data of the Mini-Si Tian survey,it successfully identified various types of variable sources,including stellar flares,supernovae,variable stars,and asteroids,while meeting requirements of reduction speed within 5 minutes.For the real observational data set,the pipeline detected one flare event,127 variable stars,and14 asteroids from three monitored sky regions.Additionally,two data sets were generated:one,a real-bogus training data set comprising 218,818 training samples,and the other,a variable star light curve data set with 421instances.These data sets will be used to train machine learning algorithms,which are planned for future integration into STRIP.展开更多
As a pathfinder of the SiTian project,the Mini-SiTian(MST)Array,employed three commercial CMOS cameras,represents a next-generation,cost-effective optical time-domain survey project.This paper focuses primarily on the...As a pathfinder of the SiTian project,the Mini-SiTian(MST)Array,employed three commercial CMOS cameras,represents a next-generation,cost-effective optical time-domain survey project.This paper focuses primarily on the precise data processing pipeline designed for wide-field,CMOS-based devices,including the removal of instrumental effects,astrometry,photometry,and flux calibration.When applying this pipeline to approximately3000 observations taken in the Field 02(f02)region by MST,the results demonstrate a remarkable astrometric precision of approximately 70–80 mas(about 0.1 pixel),an impressive calibration accuracy of approximately1 mmag in the MST zero points,and a photometric accuracy of about 4 mmag for bright stars.Our studies demonstrate that MST CMOS can achieve photometric accuracy comparable to that of CCDs,highlighting the feasibility of large-scale CMOS-based optical time-domain surveys and their potential applications for cost optimization in future large-scale time-domain surveys,like the SiTian project.展开更多
Power converters are essential components in modern life,being widely used in industry,automation,transportation,and household appliances.In many critical applications,their failure can lead not only to financial loss...Power converters are essential components in modern life,being widely used in industry,automation,transportation,and household appliances.In many critical applications,their failure can lead not only to financial losses due to operational downtime but also to serious risks to human safety.The capacitors forming the output filter,typically aluminumelectrolytic capacitors(AECs),are among the most critical and susceptible components in power converters.The electrolyte in AECs often evaporates over time,causing the internal resistance to rise and the capacitance to drop,ultimately leading to component failure.Detecting this fault requires measuring the current in the capacitor,rendering the method invasive and frequently impractical due to spatial constraints or operational limitations imposed by the integration of a current sensor in the capacitor branch.This article proposes the implementation of an online noninvasive fault diagnosis technique for estimating the Equivalent Series Resistance(ESR)and Capacitance(C)values of the capacitor,employing a combination of signal processing techniques(SPT)and machine learning(ML)algorithms.This solution relies solely on the converter’s input and output signals,therefore making it a non-invasive approach.The ML algorithm used was linear regression,applied to 27 attributes,21 of which were generated through feature engineering to enhance the model’s performance.The proposed solution demonstrates an R^(2) score greater than 0.99 in the estimation of both ESR and C.展开更多
文摘Low-voltage direct current(DC)microgrids have recently emerged as a promising and viable alternative to traditional alternating cur-rent(AC)microgrids,offering numerous advantages.Consequently,researchers are exploring the potential of DC microgrids across var-ious configurations.However,despite the sustainability and accuracy offered by DC microgrids,they pose various challenges when integrated into modern power distribution systems.Among these challenges,fault diagnosis holds significant importance.Rapid fault detection in DC microgrids is essential to maintain stability and ensure an uninterrupted power supply to critical loads.A primary chal-lenge is the lack of standards and guidelines for the protection and safety of DC microgrids,including fault detection,location,and clear-ing procedures for both grid-connected and islanded modes.In response,this study presents a brief overview of various approaches for protecting DC microgrids.
基金Supported by Project of Guangxi Zhuang Autonomous Region Administration of Traditional Chinese Medicine(GXZYA20230001)Research Fund Project of Guangxi Zhuang Autonomous Region Medicinal Botanical Garden(202304).
文摘This paper systematically categorizes the primary composition of star anise(Illicium verum),including volatile oils,flavonoids,phenolic acids,and sesquiterpene lactones,and further analyzes the pharmacological activities,such as antibacterial,analgesic,anti-inflammatory,and antioxidant effects.Additionally,it summarizes key aspects of extraction techniques,analytical methods,and fresh material processing technologies.The objective is to provide a robust foundation for enhancing research methods and technological standards related to star anise,thereby improving resource utilization efficiency and facilitating its industrial applications.
基金supported by the National Natural Science Foundation of China (No. 41004055)
文摘Based on the dual source cumulative rotation technique in the time-domain proposed by Zeng and MacBeth(1993),a new algebraic processing technique for extracting shear-wave splitting parameters from multi-component VSP data in frequency-dependent medium has been developed.By using this dual source cumulative rotation technique in the frequency-domain(DCTF),anisotropic parameters,including polarization direction of the shear-waves and timedelay between the fast and slow shear-waves,can be estimated for each frequency component in the frequency domain.It avoids the possible error which comes from using a narrow-band filter in the current commonly used method.By using synthetic seismograms,the feasibility and validity of the technique was tested and a comparison with the currently used method was also given.The results demonstrate that the shear-wave splitting parameters frequency dependence can be extracted directly from four-component seismic data using the DCTF.In the presence of larger scale fractures,substantial frequency dependence would be found in the seismic frequency range,which implies that dispersion would occur at seismic frequencies.Our study shows that shear-wave anisotropy decreases as frequency increases.
基金Supported by the Fund for Independent Innovation of Agricultural Sciences in Jiangsu Province(CX(12)3080)~~
文摘This study was conducted to investigate the recipe and process of instant pickle by multiple steps with dry daylily as a raw material, and an orthogonal test was adopted to obtain the optimal recipe and process. The pickling process of the instant flavored daylily was conducted at an optimal crisp-keeping Ca Cl2 concentration at 0.050%, cooking time of 5 min, pickling time of 6 h and a salt concentration of 4%. The effects of various factors on product taste were in order of salt concentrationcooking timepickling timeCa Cl2 concentration.The obtained product has the characteristics of strong fragrance, crisp delicious taste and unique flavor with stomachic effect.
基金National Key Research and Development Program(2021YFB3401101)。
文摘Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This review mainly summarized the research reports on short process forming techniques for brazing and soldering materials.Firstly,the traditional process and its shortcomings were presented.Secondly,the latest research of short process forming technologies,such as continuous casting technique,atomization powder technique,solder ball forming technique,and rapid solidification technique,was summarized,and the traditional forming performance of several brazing and soldering materials was introduced.Finally,the current restrictions and research trends of short process forming technique for brazing and solder materials were put forward,providing theoretical guidance and reference for related research and technique development in brazing and soldering field.
基金supported by the National Key R&D Program of China(2017YFF0205600)the International Research Cooperation Seed Fund of Beijing University of Technology(2018A08)+1 种基金Science and Technology Project of Beijing Municipal Commission of Transport(2018-kjc-01-213)the Construction of Service Capability of Scientific and Technological Innovation-Municipal Level of Fundamental Research Funds(Scientific Research Categories)of Beijing City(PXM2019_014204_500032).
文摘In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers as they directly affect the regular service for the users.Therefore,monitoring the health status of pavement before irreversible damage occurs is essential for timely maintenance,which in turn ensures public transportation safety.Many pavement damages can be detected and analyzed by monitoring the structure dynamic responses and evaluating road surface conditions.Advanced technologies can be employed for the collection and analysis of such data,including various intrusive sensing techniques,image processing techniques,and machine learning methods.This review summarizes the state-ofthe-art of these three technologies in pavement engineering in recent years and suggests possible developments for future pavement monitoring and analysis based on these approaches.
基金Supported by Major Project of Wuhan Municipal Health Commission(WZ19A01)
文摘[Objectives]To optimize the processing technology of baked Rheum tanguticum carbon.[Methods]Firstly,the baking temperature and baking time were investigated by single factor,and the content of 5-hydroxymethylfurfural(5-HMF)was determined by HPLC.The main influencing factors of baking effect were baking temperature,baking time and tablet specifications.The L 9(34)orthogonal design experiment was carried out to optimize the processing technique of R.tanguticum carbon.[Results]The optimum processing technique was as follows:small-sized tablets,controlled oven baking temperature at(210±2)℃,and baking time of 20 min.[Conclusions]The optimum processing technique of R.tanguticum carbon is reasonable and feasible.Thus,this experiment can provide a certain reference for processing method and quality control of R.tanguticum carbon.
基金financially supported by the Innovative Funds Plan of Henan University of Technology(2020ZKCJ10)Cultivation Programme for Young Backbone Teachers in Henan University of Technology.
文摘Phosphatidylserine(PS)is the part of cell structure in the body and has many beneficial functions especially in brain-related aging diseases.Although daily foods can provide PS to human body,the amount is very limited due to its poverty in most foods.To overcome the issue,numerous studies based on PS have been reported to develop PS-related supplements.In this review,PS was comprehensively and critically reviewed from the view of resources,functions,processing techniques,patents,and prospects.For resources,animal,plant,and microorganism origins were all covered with their differences in composition profiles.For functions,benefits regarding memory,cognitive enhancement,exercise performance,reducing Alzheimer’s disease,and attention-deficit hyperactivity disorder symptoms were covered as well as the functional differences among animal-,plant-,and microorganism-based PS-related supplements.For processing techniques,traditional extracting methods from animal,plant,and microorganism tissues were comparatively discussed with enzymatic synthesis based on different reaction systems.Finally,patents of PS-related supplements were evaluated as well as their applications.This review could provide scientific and valuable support for PS industry.
基金Supported by Key Laboratory for Basic and Applied Research of Zhuang Medical Prescriptions in Colleges and Universities in Guangxi(GJKY [2017]23zyfy201707)Guangxi Key Laboratory of Zhuang and Yao Medicine(GKZJ[2014]32)Collaborative Innovation Center for Zhuang and Yao Medicines(GJKY[2013]20)
文摘[Objectives]Effects of different processing techniques on the total alkaloid content in Toddalia asiatica Lam.were investigated by ultraviolet spectrophotometry.[Methods]T.asiatica was processed by the water washing method,water boiling method,water steaming method,wine steaming method and wine processing method,and the total alkaloid content was determined by ultraviolet spectrophotometry.[Results]Different processing methods can affect the total alkaloid content in the medicinal materials.Among them,the water steaming method and the wine processing method can increase the total alkaloid content of the medicinal materials,and the degree of improvement was higher in the water steaming method;and the water boiling method,water washing method and wine steaming method can reduce the total alkaloid content of the materials,and showed a reduction order of water boiling method>water washing method>wine steaming method.[Conclusions]The water steaming method and the wine processing method can increase the total alkaloid content in T.asiatica,and the water boiling method,water washing method and wine steaming method can reduce the total alkaloid content of the medicinal material.
文摘This paper relates to the fabrication of aluminium matrix composites with various amounts of Al 2O 3 fiber and SiC whiskers by rheocasting, powder metallurgy process and liquid metal infiltration process. To analyze wetting characteristics, the cross sections of composites are examined by scanning electron microscopy(SEM). The bending tests and microhardness tests are performed to evaluate mechanical properties of composites. The results show that the composites produced by liquid metal infiltration give better properties than those produced by rheocasting or powder metallurgy process, primarily due to the decrease of porosity and reinforcement cluster. For liquid metal infiltration composites, a good adhesion between the fiber and matrix is found. Three points bending test results show that there is an increase in flexural modulus with reinforcement contents. In addition, a series of microhardness tests are conducted to determine the effect of heat treatment on the mechanical property of Al 2O 3/Al composites.
文摘The rapid developing of the fourth generation(4G)wireless communications has aroused tremendous demands for high speed data transmission due to the dissemination of various types of the intelligent user terminals as well as the wireless multi-media services.It is predicted that the network throughput will increase
基金Projects(61603393,61741318)supported in part by the National Natural Science Foundation of ChinaProject(BK20160275)supported by the Natural Science Foundation of Jiangsu Province,China+1 种基金Project(2015M581885)supported by the Postdoctoral Science Foundation of ChinaProject(PAL-N201706)supported by the Open Project Foundation of State Key Laboratory of Synthetical Automation for Process Industries of Northeastern University,China
文摘As a production quality index of hematite grinding process,particle size(PS)is hard to be measured in real time.To achieve the PS estimation,this paper proposes a novel data driven model of PS using stochastic configuration network(SCN)with robust technique,namely,robust SCN(RSCN).Firstly,this paper proves the universal approximation property of RSCN with weighted least squares technique.Secondly,three robust algorithms are presented by employing M-estimation with Huber loss function,M-estimation with interquartile range(IQR)and nonparametric kernel density estimation(NKDE)function respectively to set the penalty weight.Comparison experiments are first carried out based on the UCI standard data sets to verify the effectiveness of these methods,and then the data-driven PS model based on the robust algorithms are established and verified.Experimental results show that the RSCN has an excellent performance for the PS estimation.
文摘The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery.
基金financially supported by the National Key Research and Development Program of China(2022YFC3004601)the National Natural Science Foundation of China(52204084)the Science,Technology and Innovation Project of Xiongan New Area(2023XAGG0061).
文摘1.Introduction Various geological phenomena on the surface and in the interior of the Earth,as well as their associated physical and chemical pro-cesses,are closely correlated with the action of in situ rock stress[1-5].Understanding the rock stress state at great depths is not only an indispensable foundation for solving scientific problems associated with geology,geophysics,and geodynamics-such as plate-driving mechanisms,the earth’s energy equilibrium,earth-quake mechanisms,and tectonic activities-but also a necessary prerequisite for the evaluation,exploitation,and disposal of deep energy and resources,such as coal and metal minerals.Due to the complexity and uncertainty of the origin of in situ rock stress,it is a difficult quantity to evaluate,in comparison with other rock properties.Currently,reliable information on the stress state in a region can only be determined through field stress measurement.Therefore,a variety of stress measurement techniques have been developed and applied worldwide to provide information on crus-tal contemporary stress at specific depth ranges[6].
基金the Weapons and Equipment Preresearch Fund(No.9140A27040414JB34079)the Specialized Research Fund for the Doctoral Program of the Military Education(No.2015JY354)
文摘Network maintenance strategy selection is a multi-objective decision making topic. It mostly depends on the uncertainty and fuzziness of decision makers and conditions. In this paper, based on analytic hierarchy process(AHP) and technique for order preference by similarity to ideal solution(TOPSIS), TOPSIS partial order method is proposed to choose the optimal maintenance strategy. This method uses AHP to determine the weights of evaluation indexes. The optimal maintenance strategy choice is given as an example to demonstrate the effectiveness of the method.
基金This work was supported by the Brain Korea 2lProject and the Grallt of Post-Doc Program, KyungpookNational University (1999).
文摘Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.
基金supported by the National Natural Science Foundation of China(NSFC,12173012 and 12473050)the Guangdong Natural Science Funds for Distinguished Young Scholars(2023B1515020049)+2 种基金the Shenzhen Science and Technology Project(JCYJ20240813104805008)the Shenzhen Key Laboratory Launching Project(No.ZDSYS20210702140800001)the Specialized Research Fund for State Key Laboratory of Solar Activity and Space Weather。
文摘The increasing demand for high-resolution solar observations has driven the development of advanced data processing and enhancement techniques for ground-based solar telescopes.This study focuses on developing a python-based package(GT-scopy)for data processing and enhancing for giant solar telescopes,with application to the 1.6 m Goode Solar Telescope(GST)at Big Bear Solar Observatory.The objective is to develop a modern data processing software for refining existing data acquisition,processing,and enhancement methodologies to achieve atmospheric effect removal and accurate alignment at the sub-pixel level,particularly within the processing levels 1.0-1.5.In this research,we implemented an integrated and comprehensive data processing procedure that includes image de-rotation,zone-of-interest selection,coarse alignment,correction for atmospheric distortions,and fine alignment at the sub-pixel level with an advanced algorithm.The results demonstrate a significant improvement in image quality,with enhanced visibility of fine solar structures both in sunspots and quiet-Sun regions.The enhanced data processing package developed in this study significantly improves the utility of data obtained from the GST,paving the way for more precise solar research and contributing to a better understanding of solar dynamics.This package can be adapted for other ground-based solar telescopes,such as the Daniel K.Inouye Solar Telescope(DKIST),the European Solar Telescope(EST),and the 8 m Chinese Giant Solar Telescope,potentially benefiting the broader solar physics community.
基金supported from the Strategic Pioneer Program of the Astronomy Large-Scale Scientific FacilityChinese Academy of Sciences and the Science and Education Integration Funding of University of Chinese Academy of Sciences+9 种基金the supports from the National Key Basic R&D Program of China via 2023YFA1608303the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0550103)the supports from the Strategic Priority Research Program of the Chinese Academy of Sciences under grant No.XDB0550000the National Natural Science Foundation of China(NSFC,grant Nos.12422303 and12261141690)the supports from the NSFC(grant No.12403024)supports from the NSFC through grant Nos.11988101 and 11933004the Postdoctoral Fellowship Program of CPSF under grant No.GZB20240731the Young Data Scientist Project of the National Astronomical Data Centerthe China Post-doctoral Science Foundation(No.2023M743447)supports from the New Cornerstone Science Foundation through the New Cornerstone Investigator Program and the XPLORER PRIZE。
文摘This paper provides a comprehensive introduction to the mini-Si Tian Real-time Image Processing pipeline(STRIP)and evaluates its operational performance.The STRIP pipeline is specifically designed for real-time alert triggering and light curve generation for transient sources.By applying the STRIP pipeline to both simulated and real observational data of the Mini-Si Tian survey,it successfully identified various types of variable sources,including stellar flares,supernovae,variable stars,and asteroids,while meeting requirements of reduction speed within 5 minutes.For the real observational data set,the pipeline detected one flare event,127 variable stars,and14 asteroids from three monitored sky regions.Additionally,two data sets were generated:one,a real-bogus training data set comprising 218,818 training samples,and the other,a variable star light curve data set with 421instances.These data sets will be used to train machine learning algorithms,which are planned for future integration into STRIP.
基金supported by the National Key Basic R&D Program of China via 2023YFA1608303the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0550103)+3 种基金the National Science Foundation of China 12422303,12403024,12222301,12173007,and 12261141690the Postdoctoral Fellowship Program of CPSF under grant Number GZB20240731the Young Data Scientist Project of the National Astronomical Data Center,and the China Post-doctoral Science Foundation No.2023M743447support from the NSFC through grant No.12303039 and No.12261141690.
文摘As a pathfinder of the SiTian project,the Mini-SiTian(MST)Array,employed three commercial CMOS cameras,represents a next-generation,cost-effective optical time-domain survey project.This paper focuses primarily on the precise data processing pipeline designed for wide-field,CMOS-based devices,including the removal of instrumental effects,astrometry,photometry,and flux calibration.When applying this pipeline to approximately3000 observations taken in the Field 02(f02)region by MST,the results demonstrate a remarkable astrometric precision of approximately 70–80 mas(about 0.1 pixel),an impressive calibration accuracy of approximately1 mmag in the MST zero points,and a photometric accuracy of about 4 mmag for bright stars.Our studies demonstrate that MST CMOS can achieve photometric accuracy comparable to that of CCDs,highlighting the feasibility of large-scale CMOS-based optical time-domain surveys and their potential applications for cost optimization in future large-scale time-domain surveys,like the SiTian project.
文摘Power converters are essential components in modern life,being widely used in industry,automation,transportation,and household appliances.In many critical applications,their failure can lead not only to financial losses due to operational downtime but also to serious risks to human safety.The capacitors forming the output filter,typically aluminumelectrolytic capacitors(AECs),are among the most critical and susceptible components in power converters.The electrolyte in AECs often evaporates over time,causing the internal resistance to rise and the capacitance to drop,ultimately leading to component failure.Detecting this fault requires measuring the current in the capacitor,rendering the method invasive and frequently impractical due to spatial constraints or operational limitations imposed by the integration of a current sensor in the capacitor branch.This article proposes the implementation of an online noninvasive fault diagnosis technique for estimating the Equivalent Series Resistance(ESR)and Capacitance(C)values of the capacitor,employing a combination of signal processing techniques(SPT)and machine learning(ML)algorithms.This solution relies solely on the converter’s input and output signals,therefore making it a non-invasive approach.The ML algorithm used was linear regression,applied to 27 attributes,21 of which were generated through feature engineering to enhance the model’s performance.The proposed solution demonstrates an R^(2) score greater than 0.99 in the estimation of both ESR and C.