Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as ...Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV light was affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly.Different affiliation methods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature(Tg) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.展开更多
Digital twin(DT)framework is introduced in the context of application for power grid online analysis.In the development process of a new power grid real-time online analysis system,an online analysis digital twin(OADT...Digital twin(DT)framework is introduced in the context of application for power grid online analysis.In the development process of a new power grid real-time online analysis system,an online analysis digital twin(OADT)has been implemented to realize the new online analysis architecture.The OADT approach is presented and its prominent features are discussed.The presentation,discussion,and performance testing are based on a large-scale grid network model(40K+buses),exported directly from the EMS system of an actual power grid.A plan to apply the OADT approach to digitize power grid dispatching rules is also outlined.展开更多
The unprecedented operational complexity and se-curity risks in operating the Chinese UHV AC/DC power grid calls for a new generation of real-time(sec-order)online analysis systems to provide decision support.Our rece...The unprecedented operational complexity and se-curity risks in operating the Chinese UHV AC/DC power grid calls for a new generation of real-time(sec-order)online analysis systems to provide decision support.Our recent Digital Twin based online analysis research and development work to address the needs is presented.In addition,a high-level solution architec-ture for the future real-time online analysis systems is proposed for realizing:a)The delay of the virtual model to mirror the physical power grid is in sub-sec range;b)The downstream online analysis applications could have sec-order responsiveness.展开更多
The automation of traditional Chinese medicine(TCM)pharmaceuticals has driven the development of process analysis from offline to online.Most of common online process analytical technologies are based on spectroscopy,...The automation of traditional Chinese medicine(TCM)pharmaceuticals has driven the development of process analysis from offline to online.Most of common online process analytical technologies are based on spectroscopy,making the identification and quantification of specific ingredients still a challenge.Herein,we developed a quality control(QC)system for monitoring TCM pharmaceuticals based on paper spray ionization miniature mass spectrometry(mini-MS).It enabled real-time online qualitative and quantitative detection of target ingredients in herbal extracts using mini-MS without chromatographic separation for the first time.Dynamic changes of alkaloids in Aconiti Lateralis Radix Praeparata(Fuzi)during decoction were used as examples,and the scientific principle of Fuzi compatibility was also investigated.Finally,the system was verified to work stably at the hourly level for pilot-scale extraction.This mini-MS based online analytical system is expected to be further developed for QC applications in a wider range of pharmaceutical processes.展开更多
The fast-growing demand of computational fluid dynamics（CFD） application for computing resources stimulates the development of high performance computing（HPC） and meanwhile raises new requirements for the technolo...The fast-growing demand of computational fluid dynamics（CFD） application for computing resources stimulates the development of high performance computing（HPC） and meanwhile raises new requirements for the technology of parallel application performance monitor and analysis.In response to large-scale and long-time running for the application of CFD,online and scalable performance analysis technology is required to optimize the parallel programs as well as to improve their operational efficiency.As a result,this research implements a scalable infrastructure for online performance analysis on CFD application with homogeneous or heterogeneous system.The infrastructure is part of the parallel application performance monitor and analysis system（PAPMAS） and is composed of two modules which are scalable data transmission module and data storage module.The paper analyzes and elaborates this infrastructure in detail with respect to its design and implementation.Furthermore,some experiments are carried out to verify the rationality and high efficiency of this infrastructure that could be adopted to meet the practical needs.展开更多
Background:The small nematode Caenorhabditis elegans(C.elegans)is an excellent model organism for studying the molecular and cellular basis of nervous system function.Since it has a nervous system containing only 302 ...Background:The small nematode Caenorhabditis elegans(C.elegans)is an excellent model organism for studying the molecular and cellular basis of nervous system function.Since it has a nervous system containing only 302 neurons and the precise position of each of these neurons is known,the little worm gives us a shortcut to understand how different behaviors are modulated by the nervous system.However,to study the relationship between genes and behavior in the nematode,it is inconvenient and a cost of time to analyze the locomotion difference between the mutants and the wild type worm.As a matter of fact,we need an automated behavior analysis system to accelerate the research.展开更多
Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it ...Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it is necessary for the quality of hydrogen to adhere to the standards set by ISO 14687:2019,which sets maximum limits for 14 impurities in hydrogen,aiming to prevent any degradation of fuel cell performance.Ammonia(NH_(3))is a prominent pollutant in fuel cells,and accurate measurements of its concentration are crucial for hydrogen fuel cell quantity.In this study,a novel detection platform was developed for determining NH_(3)in real hydrogen samples.The online analysis platform integrates a self-developed online dilution module with a Fourier transform infrared spectrometer(ODM-FTIR).The ODM-FTIR can be operated fully automatically with remote operation.Under the optimum conditions,this method achieved a wide linear range between(50∼1000)nmol/mol.The limit of detection(LOD)was as low as 2 nmol/mol with a relative standard deviation(RSD,n=7)of 3.6%at a content of 50 nmol/mol.To ensure that the quality of the hydrogen products meets the requirement of proton exchange membrane fuel cell vehicles(PEMFCV),the developed ODM-FTIR system was applied to monitor the NH_(3)content in Chengdu Hydrogen Energy Co.,Ltd.for 21 days during Chengdu 2021 FISU World University Games.The proposed method retains several unique advantages,including a low detection limit,excellent repeatability,high accuracy,high speed,good stability,and calibration flexibility.It is an effective analytical method for accurately quantifying NH_(3)in hydrogen,especially suitable for online analysis.It also provides a new idea for the analysis of other impurity components in hydrogen.展开更多
The adsorption behavior of butyl xanthate on the surface of lead oxide was investigated using continuous online in situ attenuated total reflectance Fourier transform infrared（ATR-FTIR） spectroscopy technique and tw...The adsorption behavior of butyl xanthate on the surface of lead oxide was investigated using continuous online in situ attenuated total reflectance Fourier transform infrared（ATR-FTIR） spectroscopy technique and two dimensional（2D） correlation analysis.The adsorbed layer studied was prepared by coating α-PbO particles onto the surfaces of the ZnSe crystal.The appearance of spectral peaks at 1203 cm^-1,1033 cm^-1 and their red shift indicated the formation and aggregation of xanthate at the surface of α-PbO.According to 1R intensity changes after rinsing with deionized water and a NaOH solution,the adsorption was proved to be a chemisorption type.The competition between xanthate and OH^- for the surfaces leads to desorption of xanthate at higher pH.The technique of 2D correlation ATR-FTIR spectroscopy was used to evaluate the changing order of spectral intensities in the adsorption process,and the results indicated that xanthate micelles were formed at the surfaces.The adsorption kinetics of butyl xanthate was found to be a pseudo-second-order reaction model and the adsorption capacity of butyl xanthate at α-PbO was as high as 281 mg g^-1 after 150 min.展开更多
Based on the analysis of the unique shapes and writing styles of Uyghur characters,we design a framework for prototype character recognition system and carry out a systematic theoretical and experimental research on i...Based on the analysis of the unique shapes and writing styles of Uyghur characters,we design a framework for prototype character recognition system and carry out a systematic theoretical and experimental research on its modules.In the preprocessing procedure,we use the linear and nonlinear normalization based on dot density method.Both structural and statistical features are extracted due to the fact that there are some very similar characters in Uyghur literature.In clustering analysis,we adopt the dynamic clustering algorithm based on the minimum spanning tree（MST）,and use the k-nearest neighbor matching classification as classifier.The testing results of prototype system show that the recognition rates for characters of the four different types（independent,suffix,intermediate,and initial type） are 74.67%,70.42%,63.33%,and 72.02%,respectively;the recognition rates for the case of five candidates for those characters are 94.34%,94.19%,93.15%,and 95.86%,respectively.The ideas and methods used in this paper have some commonality and usefulness for the recognition of other characters that belong to Altaic languages family.展开更多
Raw materials have a signcant influence on the qu.ality of the final refractory products, as the crude ore often comes for processing with significant variations in chemical and mineralogical composition. Therefore, i...Raw materials have a signcant influence on the qu.ality of the final refractory products, as the crude ore often comes for processing with significant variations in chemical and mineralogical composition. Therefore, it is necessary to guarantee the stable quality of raw materials with pre-assigned qualitative factors. It is possible to solve these problems by separating raw materials by grades, including the rejection of the portions of material unsuitable for specific application, and by reasonable control of the processing parameters based on real-time infirmation about chemical composition of raw materials. This can be effectively achieved by MAYA laser ele- mental analyzers based on LIBS. Being applied in ex traction, beneficiation and processing of the mineral raw materials, LIBS analyzers can be used for automatic sor ting ＂ the ore extracted or crushed and automatic dosage of components to stabilize the composition of raw material mixtures.展开更多
The public content increasingly available on the Internet, especially in online forums, enables researchers to study society in new ways. However, qualitative analysis of online forums is very time consuming and most ...The public content increasingly available on the Internet, especially in online forums, enables researchers to study society in new ways. However, qualitative analysis of online forums is very time consuming and most content is not related to researchers’ interest. Consequently, analysts face the following problem: how to efficiently explore and select the content to be analyzed? This article introduces a new process to support analysts in solving this problem. This process is based on unsupervised machine learning techniques like hierarchical clustering and term co-occurrence network. A tool that helps to apply the proposed process was created to provide consolidated and structured results. This includes measurements and a content exploration interface.展开更多
The current DSA system used in the dispatching control centers in China is a near real-time analysis system with response speed in the order of minutes.Based on a review of the state-of-the-art in online analysis and ...The current DSA system used in the dispatching control centers in China is a near real-time analysis system with response speed in the order of minutes.Based on a review of the state-of-the-art in online analysis and discussion of distributed data processing and computation architecture patterns,a new online analysis architecture is proposed.The primary goal of the new architecture is to increase the online analysis response speed to the order of seconds.A reference implementation of the proposed online analysis architecture to validate the feasibility of implementing the architecture and some performance testing results are presented.展开更多
Under the background of increasingly scarce ore worldwide and increasingly fierce market competition,developing the mining industry could be strongly restricted.Intelligent ore sorting equipment not only improves ore ...Under the background of increasingly scarce ore worldwide and increasingly fierce market competition,developing the mining industry could be strongly restricted.Intelligent ore sorting equipment not only improves ore use and enhances the economic benefits of enterprises but also increases the ore grade and lessens the grinding cost and tailings production.However,long-term research on intelligent ore sorting equipment found that the factors affecting sorting efficiency mainly include ore information identification technology,equipment sorting actuator,and information processing algorithm.The high precision,strong anti-interference capability,and high speed of these factors guarantee the separation efficiency of intelligent ore sorting equipment.Color ore sorter,X-ray ore transmission sorter,dual-energy X-ray transmission ore sorter,X-ray fluorescence ore sorter,and near-infrared ore sorter have been successfully developed in accordance with the different characteristics of minerals while ensuring the accuracy of equipment sorting and improving the equipment sorting efficiency.With the continuous improvement of mine automation level,the application of online element rapid analysis technology with high speed,high precision,and strong anti-interference capability in intelligent ore sorting equipment will become an inevitable trend of equipment development in the future.Laser-induced breakdown spectroscopy,transientγneutron activation analysis,online Fourier transform infrared spectroscopy,and nuclear magnetic resonance techniques will promote the development of ore sorting equipment.In addition,the improvement and joint application of additional high-speed and high-precision operation algorithms(such as peak area,principal component analysis,artificial neural network,partial least squares,and Monte Carlo library least squares methods)are an essential part of the development of intelligent ore sorting equipment in the future.展开更多
This paper analyzes 1,662 travelogues about the Wulong tourism destination from the Mafengwo platform using literature research and network text analysis.The goal is to identify the driving factors affecting Wulong’s...This paper analyzes 1,662 travelogues about the Wulong tourism destination from the Mafengwo platform using literature research and network text analysis.The goal is to identify the driving factors affecting Wulong’s tourism service experience and suggest improvements.By extracting high-frequency words and analyzing emotions from the travelogues,tourists’conceptions and perceptions were identified and the factors affecting the tourism service experience in Wulong were summarized into six categories:tourism resource attractions,tourism transportation,tourism facilities and digital services,cultural charms,special cuisines,and environmental ambiance.Tourists’emotional perceptions of Wulong are primarily positive,with negative perceptions mainly related to unsatisfactory tourism facilities and digital services in the Wulong scenic area.This study helps the Wulong tourist destination understand the issues and deficiencies in tourists’service experiences,providing significant guidance for improving service quality and offering data support for service marketing and optimization.展开更多
Large-scale public buildings have high energy density, which on average consume 5 to 15 times more electricity than residential buildings. In Beijing, those public buildings account for about ten percent of the total ...Large-scale public buildings have high energy density, which on average consume 5 to 15 times more electricity than residential buildings. In Beijing, those public buildings account for about ten percent of the total building area, but their energy consumption （except heating） amounts to more than thirty percent of the total. Few electric meters are installed in those public buildings, however, making it more difficult to monitor how the energy is used.展开更多
Chemical component analysis is a critical challenge in Chinese herbal medicine research,involving the qualitative and quantitative identification of complex constituents in traditional Chinese medicine(TCM).However,tr...Chemical component analysis is a critical challenge in Chinese herbal medicine research,involving the qualitative and quantitative identification of complex constituents in traditional Chinese medicine(TCM).However,traditional analytical methods are insufficient for efficient and comprehensive analysis of complex composition of TCM.Limitations exist in sample preparation,instrumental technology,data processing,and activity-related quality marker research.Recent advancements have significantly improved analytical precision,enabling more comprehensive profiling of TCM components.New pretreatment methods improve extraction efficiency and detection sensitivity,while novel instrumental technologies,such as mass spectrometry imaging,preserve spatial information lost in homogenization.AI enhances data interpretation,improving accuracy and efficiency.Online activity analysis links chemical composition with bioactivity,overcoming the limitations of purely chemical profiling and enabling a more comprehensive evaluation of TCM efficacy.This perspective provides an overview of the development trends in component analysis,aiming to advance the field and support TCM modernization.展开更多
In the mass tourism era,the rising demand for personalized and high-quality experiences necessitates a distinct urban tourism image.This study examined tourists’perceptions of Harbin during non-ice and snow seasons u...In the mass tourism era,the rising demand for personalized and high-quality experiences necessitates a distinct urban tourism image.This study examined tourists’perceptions of Harbin during non-ice and snow seasons using network text analysis within the“cognitive-emotional-overall”framework and a ROST content mining tool.Our analysis of travelogues revealed that Harbin is seen as an exotic,culturally rich destination,yet tourists have limited awareness of its natural resources.While overall emotional responses from tourists were positive,facilities and services received some criticism.The views of tourists were primarily focused on popular urban sites,highlighting the need for diversification.This study contributes to the theoretical discussion on the formation of the city’s tourism image and suggests strategies that will allow Harbin to transition from a season-specific tourism model to a year-round tourism model,thereby enhancing its four-season destination brand in terms of infrastructure,industry innovation and market management.展开更多
Based on the cognitive-affective theoretical model of tourism destination image perception,this study utilizes big data mining technology to obtain Weibo comment texts from Shanghai Citywalk tourists.It then systemati...Based on the cognitive-affective theoretical model of tourism destination image perception,this study utilizes big data mining technology to obtain Weibo comment texts from Shanghai Citywalk tourists.It then systematically explores the characteristics of their tourism destination image perception through content analysis.The key findings are as follows:(1)At the cognitive image level,the attractions chosen by tourists for Citywalk form a“dual-core and multi-axis”network structure,with a preference for characteristic blocks that integrate cultural landscapes and local life scenes.The perception of the tourism environment exhibits multi-sensory interaction characteristics,which are instantaneously influenced by weather conditions.The preferred mode of transportation is the low-carbon combination of“subway+slow travel”.Furthermore,catering is deeply integrated with urban leisure,and accommodation services adequately meet short-term needs.(2)In terms of emotional image,positive emotions are dominant,primarily fueled by urban vitality,cultural collisions,and immersive experiences.Conversely,negative experiences mainly arise from crowds,high consumption costs,and adverse weather conditions.(3)The overall image perception is highly positive,evidenced by a significant willingness to revisit and recommend.However,optimization is needed concerning spatial carrying capacity and consumption affordability.Finally,the study actionable suggestions for optimizing the image of Shanghai’s Citywalk tourism destinations,thereby providing a theoretical foundation for urban micro-tourism design,promoting the development of Shanghai’s all-for-one tourism,and contributing to the establishment of a destination shared harmoniously by both residents and visitors.展开更多
The major hindrances in the energy system are ecological consciousness, lack of clean and sustainableenergy management, insufficient energy distribution–transmission–optimization, expensive power transfercosts, and ...The major hindrances in the energy system are ecological consciousness, lack of clean and sustainableenergy management, insufficient energy distribution–transmission–optimization, expensive power transfercosts, and increased customer knowledge of energy charges. Thus why, universal access to the grid with highcybersecurity, and reliability is needed to solve all these challenges. The digital twin concept turns a newdimension of technology into the world. Electric Digital Twin grid can perform online analysis of the grid inreal-time and integrates all the past and present data and express the current grid status to the producers andconsumers and also predicts the future grid status. Thus, the power grid transmission loss and location of theoverheated line and power connection missing can be detected in addition decision-making and self-healingcan possible. The future prediction saves the power grid from small to long accidents such as power outagesand even blackout problems. The whole consumers and nation feel relief from these types of accidents andsaves from large economic and business loss. The blockchain-enabled digital twin grid provides high securityfor the grid from cyberattacks. The paper conveys the framework of the electric digital twin grid and theconcept of the DT grid processing and the way of serving the producer, prosumers, consumers even the wholenation in infrastructure, education, research, economic, business, and political development.展开更多
Video surveillance applications need video data center to provide elastic virtual machine （VM） provisioning. However, the workloads of the VMs are hardly to be predicted for online video surveillance service. The un...Video surveillance applications need video data center to provide elastic virtual machine （VM） provisioning. However, the workloads of the VMs are hardly to be predicted for online video surveillance service. The unknown arrival workloads easily lead to workload skew among VMs. In this paper, we study how to balance the workload skew on online video surveillance system. First, we design the system framework for online surveillance service which con- sists of video capturing and analysis tasks. Second, we propose StreamTune, an online resource scheduling approach for workload balancing, to deal with irregular video analysis workload with the minimum number of VMs. We aim at timely balancing the workload skew on video analyzers without depending on any workload prediction method. Furthermore, we evaluate the performance of the proposed approach using a traffic surveillance application. The experimental results show that our approach is well adaptive to the variation of workload and achieves workload balance with less VMs.展开更多
基金Supported by the National Science and Technology Key Supporting Project(2013BAF08B05)the National Natural Science Foundation of China(21176137)
文摘Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV light was affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly.Different affiliation methods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature(Tg) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.
基金This work was supported by National Natural Science Foundation of China under the Grant U1766214.
文摘Digital twin(DT)framework is introduced in the context of application for power grid online analysis.In the development process of a new power grid real-time online analysis system,an online analysis digital twin(OADT)has been implemented to realize the new online analysis architecture.The OADT approach is presented and its prominent features are discussed.The presentation,discussion,and performance testing are based on a large-scale grid network model(40K+buses),exported directly from the EMS system of an actual power grid.A plan to apply the OADT approach to digitize power grid dispatching rules is also outlined.
基金This work was supported by National Natural Science Foundation of China under the Grant U1766214.
文摘The unprecedented operational complexity and se-curity risks in operating the Chinese UHV AC/DC power grid calls for a new generation of real-time(sec-order)online analysis systems to provide decision support.Our recent Digital Twin based online analysis research and development work to address the needs is presented.In addition,a high-level solution architec-ture for the future real-time online analysis systems is proposed for realizing:a)The delay of the virtual model to mirror the physical power grid is in sub-sec range;b)The downstream online analysis applications could have sec-order responsiveness.
基金supported by Ministry of Science and Technology of the People's Republic of China(Grant No.:2022YFC3502300)Beijing Natural Science Foundation(Grant No.:L222150)+2 种基金the National Natural Science Foundation of China(Grant No.:82072247)the second batch of“Ten thousand plan”National High Level Talents Special Support Plan(Grant No.:W02020052)Beijing University of Chinese Medicine(Grant Nos.:XJYS21005,JY21024,MSGZF-202001,2022-syjs-05,and 2022-syjs-10).
文摘The automation of traditional Chinese medicine(TCM)pharmaceuticals has driven the development of process analysis from offline to online.Most of common online process analytical technologies are based on spectroscopy,making the identification and quantification of specific ingredients still a challenge.Herein,we developed a quality control(QC)system for monitoring TCM pharmaceuticals based on paper spray ionization miniature mass spectrometry(mini-MS).It enabled real-time online qualitative and quantitative detection of target ingredients in herbal extracts using mini-MS without chromatographic separation for the first time.Dynamic changes of alkaloids in Aconiti Lateralis Radix Praeparata(Fuzi)during decoction were used as examples,and the scientific principle of Fuzi compatibility was also investigated.Finally,the system was verified to work stably at the hourly level for pilot-scale extraction.This mini-MS based online analytical system is expected to be further developed for QC applications in a wider range of pharmaceutical processes.
基金Aeronautical Science Foundation of China(2010ZA04001)National Natural Science Foundation of China (61073013,90818024)
文摘The fast-growing demand of computational fluid dynamics（CFD） application for computing resources stimulates the development of high performance computing（HPC） and meanwhile raises new requirements for the technology of parallel application performance monitor and analysis.In response to large-scale and long-time running for the application of CFD,online and scalable performance analysis technology is required to optimize the parallel programs as well as to improve their operational efficiency.As a result,this research implements a scalable infrastructure for online performance analysis on CFD application with homogeneous or heterogeneous system.The infrastructure is part of the parallel application performance monitor and analysis system（PAPMAS） and is composed of two modules which are scalable data transmission module and data storage module.The paper analyzes and elaborates this infrastructure in detail with respect to its design and implementation.Furthermore,some experiments are carried out to verify the rationality and high efficiency of this infrastructure that could be adopted to meet the practical needs.
文摘Background:The small nematode Caenorhabditis elegans(C.elegans)is an excellent model organism for studying the molecular and cellular basis of nervous system function.Since it has a nervous system containing only 302 neurons and the precise position of each of these neurons is known,the little worm gives us a shortcut to understand how different behaviors are modulated by the nervous system.However,to study the relationship between genes and behavior in the nematode,it is inconvenient and a cost of time to analyze the locomotion difference between the mutants and the wild type worm.As a matter of fact,we need an automated behavior analysis system to accelerate the research.
基金financial support by Sichuan Science and Technology,China(No.2023YFG0070).
文摘Fuel cell electric vehicles hold great promise for a diverse range of applications in reducing greenhouse gas emissions.In power fuel cell systems,hydrogen fuel serves as an energy vector.To ensure its suitability,it is necessary for the quality of hydrogen to adhere to the standards set by ISO 14687:2019,which sets maximum limits for 14 impurities in hydrogen,aiming to prevent any degradation of fuel cell performance.Ammonia(NH_(3))is a prominent pollutant in fuel cells,and accurate measurements of its concentration are crucial for hydrogen fuel cell quantity.In this study,a novel detection platform was developed for determining NH_(3)in real hydrogen samples.The online analysis platform integrates a self-developed online dilution module with a Fourier transform infrared spectrometer(ODM-FTIR).The ODM-FTIR can be operated fully automatically with remote operation.Under the optimum conditions,this method achieved a wide linear range between(50∼1000)nmol/mol.The limit of detection(LOD)was as low as 2 nmol/mol with a relative standard deviation(RSD,n=7)of 3.6%at a content of 50 nmol/mol.To ensure that the quality of the hydrogen products meets the requirement of proton exchange membrane fuel cell vehicles(PEMFCV),the developed ODM-FTIR system was applied to monitor the NH_(3)content in Chengdu Hydrogen Energy Co.,Ltd.for 21 days during Chengdu 2021 FISU World University Games.The proposed method retains several unique advantages,including a low detection limit,excellent repeatability,high accuracy,high speed,good stability,and calibration flexibility.It is an effective analytical method for accurately quantifying NH_(3)in hydrogen,especially suitable for online analysis.It also provides a new idea for the analysis of other impurity components in hydrogen.
基金supported by the National Nature Science Foundation of China(Nos.51274104,50874052)National Key Basic Research Program of China(973,No.2011CB933700)
文摘The adsorption behavior of butyl xanthate on the surface of lead oxide was investigated using continuous online in situ attenuated total reflectance Fourier transform infrared（ATR-FTIR） spectroscopy technique and two dimensional（2D） correlation analysis.The adsorbed layer studied was prepared by coating α-PbO particles onto the surfaces of the ZnSe crystal.The appearance of spectral peaks at 1203 cm^-1,1033 cm^-1 and their red shift indicated the formation and aggregation of xanthate at the surface of α-PbO.According to 1R intensity changes after rinsing with deionized water and a NaOH solution,the adsorption was proved to be a chemisorption type.The competition between xanthate and OH^- for the surfaces leads to desorption of xanthate at higher pH.The technique of 2D correlation ATR-FTIR spectroscopy was used to evaluate the changing order of spectral intensities in the adsorption process,and the results indicated that xanthate micelles were formed at the surfaces.The adsorption kinetics of butyl xanthate was found to be a pseudo-second-order reaction model and the adsorption capacity of butyl xanthate at α-PbO was as high as 281 mg g^-1 after 150 min.
基金Supported by the National Natural Science Foundation of China (61065001)
文摘Based on the analysis of the unique shapes and writing styles of Uyghur characters,we design a framework for prototype character recognition system and carry out a systematic theoretical and experimental research on its modules.In the preprocessing procedure,we use the linear and nonlinear normalization based on dot density method.Both structural and statistical features are extracted due to the fact that there are some very similar characters in Uyghur literature.In clustering analysis,we adopt the dynamic clustering algorithm based on the minimum spanning tree（MST）,and use the k-nearest neighbor matching classification as classifier.The testing results of prototype system show that the recognition rates for characters of the four different types（independent,suffix,intermediate,and initial type） are 74.67%,70.42%,63.33%,and 72.02%,respectively;the recognition rates for the case of five candidates for those characters are 94.34%,94.19%,93.15%,and 95.86%,respectively.The ideas and methods used in this paper have some commonality and usefulness for the recognition of other characters that belong to Altaic languages family.
文摘Raw materials have a signcant influence on the qu.ality of the final refractory products, as the crude ore often comes for processing with significant variations in chemical and mineralogical composition. Therefore, it is necessary to guarantee the stable quality of raw materials with pre-assigned qualitative factors. It is possible to solve these problems by separating raw materials by grades, including the rejection of the portions of material unsuitable for specific application, and by reasonable control of the processing parameters based on real-time infirmation about chemical composition of raw materials. This can be effectively achieved by MAYA laser ele- mental analyzers based on LIBS. Being applied in ex traction, beneficiation and processing of the mineral raw materials, LIBS analyzers can be used for automatic sor ting ＂ the ore extracted or crushed and automatic dosage of components to stabilize the composition of raw material mixtures.
基金sponsored by CNPq(Brazilian Council for Research and Development),process 142620/2009-2FAPESP(State of Sao Paulo Research Foundation),process 2010/20564-8 and 2011/19850-9.
文摘The public content increasingly available on the Internet, especially in online forums, enables researchers to study society in new ways. However, qualitative analysis of online forums is very time consuming and most content is not related to researchers’ interest. Consequently, analysts face the following problem: how to efficiently explore and select the content to be analyzed? This article introduces a new process to support analysts in solving this problem. This process is based on unsupervised machine learning techniques like hierarchical clustering and term co-occurrence network. A tool that helps to apply the proposed process was created to provide consolidated and structured results. This includes measurements and a content exploration interface.
基金This work was supported by the State Grid of China under the“Thousand Talents Plan”special research grant(5206001600A3).
文摘The current DSA system used in the dispatching control centers in China is a near real-time analysis system with response speed in the order of minutes.Based on a review of the state-of-the-art in online analysis and discussion of distributed data processing and computation architecture patterns,a new online analysis architecture is proposed.The primary goal of the new architecture is to increase the online analysis response speed to the order of seconds.A reference implementation of the proposed online analysis architecture to validate the feasibility of implementing the architecture and some performance testing results are presented.
基金supported by the National Science and Technology Support Program of China(No.2012BAC11B07)the Jiangxi Science and Technology Innovation Base Plan(No.20212BCD42017)。
文摘Under the background of increasingly scarce ore worldwide and increasingly fierce market competition,developing the mining industry could be strongly restricted.Intelligent ore sorting equipment not only improves ore use and enhances the economic benefits of enterprises but also increases the ore grade and lessens the grinding cost and tailings production.However,long-term research on intelligent ore sorting equipment found that the factors affecting sorting efficiency mainly include ore information identification technology,equipment sorting actuator,and information processing algorithm.The high precision,strong anti-interference capability,and high speed of these factors guarantee the separation efficiency of intelligent ore sorting equipment.Color ore sorter,X-ray ore transmission sorter,dual-energy X-ray transmission ore sorter,X-ray fluorescence ore sorter,and near-infrared ore sorter have been successfully developed in accordance with the different characteristics of minerals while ensuring the accuracy of equipment sorting and improving the equipment sorting efficiency.With the continuous improvement of mine automation level,the application of online element rapid analysis technology with high speed,high precision,and strong anti-interference capability in intelligent ore sorting equipment will become an inevitable trend of equipment development in the future.Laser-induced breakdown spectroscopy,transientγneutron activation analysis,online Fourier transform infrared spectroscopy,and nuclear magnetic resonance techniques will promote the development of ore sorting equipment.In addition,the improvement and joint application of additional high-speed and high-precision operation algorithms(such as peak area,principal component analysis,artificial neural network,partial least squares,and Monte Carlo library least squares methods)are an essential part of the development of intelligent ore sorting equipment in the future.
基金Master’s Degree Innovation Project of Chongqing University of Science and Technology“Research on the Emotional Value of Tourists in Ethnic Tourism Sites:The Case of Yotkan Old Town”(Project No.YKJCX2320907).
文摘This paper analyzes 1,662 travelogues about the Wulong tourism destination from the Mafengwo platform using literature research and network text analysis.The goal is to identify the driving factors affecting Wulong’s tourism service experience and suggest improvements.By extracting high-frequency words and analyzing emotions from the travelogues,tourists’conceptions and perceptions were identified and the factors affecting the tourism service experience in Wulong were summarized into six categories:tourism resource attractions,tourism transportation,tourism facilities and digital services,cultural charms,special cuisines,and environmental ambiance.Tourists’emotional perceptions of Wulong are primarily positive,with negative perceptions mainly related to unsatisfactory tourism facilities and digital services in the Wulong scenic area.This study helps the Wulong tourist destination understand the issues and deficiencies in tourists’service experiences,providing significant guidance for improving service quality and offering data support for service marketing and optimization.
文摘Large-scale public buildings have high energy density, which on average consume 5 to 15 times more electricity than residential buildings. In Beijing, those public buildings account for about ten percent of the total building area, but their energy consumption （except heating） amounts to more than thirty percent of the total. Few electric meters are installed in those public buildings, however, making it more difficult to monitor how the energy is used.
基金supported by the National Natural Science Foundation of China(No.82461160264,82474056,82404854)the grant from Science and Technology Commission of Shanghai Municipality(No.21S21902400)+3 种基金Shanghai Municipal Health Commission(No.2022XD037)Shanghai Magnolia Talent Plan Pujiang Project(No.23PJD113)the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2023ZD502605)the Science and Technology Development Fund,Macao SAR(No.0151/2024/AFJ)。
文摘Chemical component analysis is a critical challenge in Chinese herbal medicine research,involving the qualitative and quantitative identification of complex constituents in traditional Chinese medicine(TCM).However,traditional analytical methods are insufficient for efficient and comprehensive analysis of complex composition of TCM.Limitations exist in sample preparation,instrumental technology,data processing,and activity-related quality marker research.Recent advancements have significantly improved analytical precision,enabling more comprehensive profiling of TCM components.New pretreatment methods improve extraction efficiency and detection sensitivity,while novel instrumental technologies,such as mass spectrometry imaging,preserve spatial information lost in homogenization.AI enhances data interpretation,improving accuracy and efficiency.Online activity analysis links chemical composition with bioactivity,overcoming the limitations of purely chemical profiling and enabling a more comprehensive evaluation of TCM efficacy.This perspective provides an overview of the development trends in component analysis,aiming to advance the field and support TCM modernization.
文摘In the mass tourism era,the rising demand for personalized and high-quality experiences necessitates a distinct urban tourism image.This study examined tourists’perceptions of Harbin during non-ice and snow seasons using network text analysis within the“cognitive-emotional-overall”framework and a ROST content mining tool.Our analysis of travelogues revealed that Harbin is seen as an exotic,culturally rich destination,yet tourists have limited awareness of its natural resources.While overall emotional responses from tourists were positive,facilities and services received some criticism.The views of tourists were primarily focused on popular urban sites,highlighting the need for diversification.This study contributes to the theoretical discussion on the formation of the city’s tourism image and suggests strategies that will allow Harbin to transition from a season-specific tourism model to a year-round tourism model,thereby enhancing its four-season destination brand in terms of infrastructure,industry innovation and market management.
基金The National Natural Science Foundation of China(42130510)。
文摘Based on the cognitive-affective theoretical model of tourism destination image perception,this study utilizes big data mining technology to obtain Weibo comment texts from Shanghai Citywalk tourists.It then systematically explores the characteristics of their tourism destination image perception through content analysis.The key findings are as follows:(1)At the cognitive image level,the attractions chosen by tourists for Citywalk form a“dual-core and multi-axis”network structure,with a preference for characteristic blocks that integrate cultural landscapes and local life scenes.The perception of the tourism environment exhibits multi-sensory interaction characteristics,which are instantaneously influenced by weather conditions.The preferred mode of transportation is the low-carbon combination of“subway+slow travel”.Furthermore,catering is deeply integrated with urban leisure,and accommodation services adequately meet short-term needs.(2)In terms of emotional image,positive emotions are dominant,primarily fueled by urban vitality,cultural collisions,and immersive experiences.Conversely,negative experiences mainly arise from crowds,high consumption costs,and adverse weather conditions.(3)The overall image perception is highly positive,evidenced by a significant willingness to revisit and recommend.However,optimization is needed concerning spatial carrying capacity and consumption affordability.Finally,the study actionable suggestions for optimizing the image of Shanghai’s Citywalk tourism destinations,thereby providing a theoretical foundation for urban micro-tourism design,promoting the development of Shanghai’s all-for-one tourism,and contributing to the establishment of a destination shared harmoniously by both residents and visitors.
文摘The major hindrances in the energy system are ecological consciousness, lack of clean and sustainableenergy management, insufficient energy distribution–transmission–optimization, expensive power transfercosts, and increased customer knowledge of energy charges. Thus why, universal access to the grid with highcybersecurity, and reliability is needed to solve all these challenges. The digital twin concept turns a newdimension of technology into the world. Electric Digital Twin grid can perform online analysis of the grid inreal-time and integrates all the past and present data and express the current grid status to the producers andconsumers and also predicts the future grid status. Thus, the power grid transmission loss and location of theoverheated line and power connection missing can be detected in addition decision-making and self-healingcan possible. The future prediction saves the power grid from small to long accidents such as power outagesand even blackout problems. The whole consumers and nation feel relief from these types of accidents andsaves from large economic and business loss. The blockchain-enabled digital twin grid provides high securityfor the grid from cyberattacks. The paper conveys the framework of the electric digital twin grid and theconcept of the DT grid processing and the way of serving the producer, prosumers, consumers even the wholenation in infrastructure, education, research, economic, business, and political development.
文摘Video surveillance applications need video data center to provide elastic virtual machine （VM） provisioning. However, the workloads of the VMs are hardly to be predicted for online video surveillance service. The unknown arrival workloads easily lead to workload skew among VMs. In this paper, we study how to balance the workload skew on online video surveillance system. First, we design the system framework for online surveillance service which con- sists of video capturing and analysis tasks. Second, we propose StreamTune, an online resource scheduling approach for workload balancing, to deal with irregular video analysis workload with the minimum number of VMs. We aim at timely balancing the workload skew on video analyzers without depending on any workload prediction method. Furthermore, we evaluate the performance of the proposed approach using a traffic surveillance application. The experimental results show that our approach is well adaptive to the variation of workload and achieves workload balance with less VMs.
