In conjunction with association rules for data mining, the connections between testing indices and strong and weak association rules were determined, and new derivative rules were obtained by further reasoning. Associ...In conjunction with association rules for data mining, the connections between testing indices and strong and weak association rules were determined, and new derivative rules were obtained by further reasoning. Association rules were used to analyze correlation and check consistency between indices. This study shows that the judgment obtained by weak association rules or non-association rules is more accurate and more credible than that obtained by strong association rules. When the testing grades of two indices in the weak association rules are inconsistent, the testing grades of indices are more likely to be erroneous, and the mistakes are often caused by human factors. Clustering data mining technology was used to analyze the reliability of a diagnosis, or to perform health diagnosis directly. Analysis showed that the clustering results are related to the indices selected, and that if the indices selected are more significant, the characteristics of clustering results are also more significant, and the analysis or diagnosis is more credible. The indices and diagnosis analysis function produced by this study provide a necessary theoretical foundation and new ideas for the development of hydraulic metal structure health diagnosis technology.展开更多
This paper presents a terahertz（THz）band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype.This iris inductive window coupled waveguide filter was designed by using 8 resonan...This paper presents a terahertz（THz）band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype.This iris inductive window coupled waveguide filter was designed by using 8 resonant cavities with a center frequency of 345 GHz and a 7% bandwidth.The final design fulfills the desired specifications and presents the minimum insertion loss of 1.55 d B and the return loss of less than 15 d B at 345 GHz.The stop-band rejection is50 d B off the center frequency about 30 GHz,which means it has a good performance of high stop-band suppression.Compared with the recent development of THz filters,this filter possesses the characteristic of simple structure and is easy to machining.展开更多
In recent years, China has stepped up its efforts to open its economy to the outside world, thus effectively promoting the sound development of the social economy and creating a good foundation for the development and...In recent years, China has stepped up its efforts to open its economy to the outside world, thus effectively promoting the sound development of the social economy and creating a good foundation for the development and expansion of the field of science and technology. As a result, a large number of new technologies have been developed and widely used by people in many fields with good results. Especially in the civil engineering industry, the continuous improvement of engineering construction technology has laid a solid foundation for the continuous improvement of civil engineering construction quality. At present, China's urbanization construction has been widely implemented, and the number of civil construction projects in various regions has gradually increased, which makes people put forward higher requirements on the construction technology level of construction projects. Steel structure is an important part in civil engineering projects. The construction effect of steel structure is often closely related to the construction quality of civil engineering projects, and it is also an important foundation for the sustainable and stable development of civil engineering industry. In view of this, this article mainly focuses on the comprehensive and in-depth research and analysis of steel structure construction technology in civil engineering construction, hoping to be helpful for the future good development of the civil engineering industry in our country.展开更多
This paper briefs the current clean production and consumption levels of coal in China and the pollution harmbrought to the atmospheric environment, present status and orientation of clean coal technology development ...This paper briefs the current clean production and consumption levels of coal in China and the pollution harmbrought to the atmospheric environment, present status and orientation of clean coal technology development in Chinacoal industry, progress and perspective of clean coal power generation technology in China, as well as application andmarket of flue gas desulphurization technology in coal-fired power plants.[展开更多
Decarbonization and decontamination of the iron and steel industry(ISI),which contributes up to 15%to anthropogenic CO_(2) emissions(or carbon emissions)and significant proportions of air and water pollutant emissions...Decarbonization and decontamination of the iron and steel industry(ISI),which contributes up to 15%to anthropogenic CO_(2) emissions(or carbon emissions)and significant proportions of air and water pollutant emissions in China,are challenged by the huge demand for steel.Carbon and pollutants often share common emission sources,indicating that emission reduction could be achieved synergistically.Here,we explored the inherent potential of measures to adjust feedstock composition and technological structure and to control the size of the ISI to achieve carbon emission reduction(CER)and pollution emission reduction(PER).We investigated five typical pollutants in this study,namely,petroleum hydrocarbon pollutants and chemical oxygen demand in wastewater,particulate matter,SO_(2),and NO_(x) in off gases,and examined synergies between CER and PER by employing cross elasticity for the period between 2022 and 2035.The results suggest that a reduction of 8.7%-11.7%in carbon emissions and 20%-31%in pollution emissions(except for particulate matter emissions)could be achieved by 2025 under a high steel scrap ratio(SSR)scenario.Here,the SSR and electric arc furnace(EAF)ratio serve critical roles in enhancing synergies between CER and PER(which vary with the type of pollutant).However,subject to a limited volume of steel scrap,a focused increase in the EAF ratio with neglection of the available supply of steel scrap to EAF facilities would lead to an increase carbon and pollution emissions.Although CER can be achieved through SSR and EAF ratio optimization,only when the crude steel production growth rate remains below 2.2%can these optimization measures maintain the emissions in 2030 at a similar level to that in 2021.Therefore,the synergistic effects between PER and CER should be considered when formulating a development route for the ISI in the future.展开更多
Photonic crystals(PC)play an increasingly important role in anti-counterfeiting,sensors,displays,and other fields because they produce adjustable structural colors through optical manipulation of photonic stopbands.Fl...Photonic crystals(PC)play an increasingly important role in anti-counterfeiting,sensors,displays,and other fields because they produce adjustable structural colors through optical manipulation of photonic stopbands.Flexible structural color materials(FSCMs)eliminate the requirement that traditional structures rely on hard substrates and the problem of poor mechanical quality caused by the stiffness of the building blocks.At the same time,different production technologies and materials provide FSCMs with different abilities to change color in response to stimulation.Therefore,they have attracted extensive attention.This paper summarizes the preparation strategy and variable structural colors of FSCMs.First,a series of preparation strategies for integrating materials with PC are summarized,including the assembly of colloidal spheres on flexible substrates,polymers,direct assembly based on polymers,and 3D printing.Subsequently,the variable structural colors of FSCMs with different stimuli,such as chemical stimuli,temperature,humidity,and mechanical stress,are described in detail.Finally,several potential directions for FSCMs manufacturing and application are introduced,and its prospects and challenges are discussed.It is believed that it will be valuable to promote the use of flexible optical materials.展开更多
Based on patent cooperation data,this study used a range of city network analysis approaches in order to explore the structure of the Chinese city network which is driven by technological knowledge flows.The results r...Based on patent cooperation data,this study used a range of city network analysis approaches in order to explore the structure of the Chinese city network which is driven by technological knowledge flows.The results revealed the spatial structure,composition structure,hierarchical structure,group structure,and control structure of Chinese city network,as well as its dynamic factors.The major findings are:1) the spatial pattern presents a diamond structure,in which Wuhan is the central city;2) although the invention patent knowledge network is the main part of the broader inter-city innovative cooperation network,it is weaker than the utility model patent;3) as the senior level cities,Beijing,Shanghai and the cities in the Zhujiang(Pearl) River Delta Region show a strong capability of both spreading and controlling technological knowledge;4) whilst a national technology alliance has preliminarily formed,regional alliances have not been adequately established;5) even though the cooperation level amongst weak connection cities is not high,such cities still play an important role in the network as a result of their location within ′structural holes′ in the network;and 6) the major driving forces facilitating inter-city technological cooperation are geographical proximity,hierarchical proximity and technological proximity.展开更多
Management Information System provides an effective way for enterprises to improve their competitive abilities. It presents a framework for improving the management models through the design and implementation of effe...Management Information System provides an effective way for enterprises to improve their competitive abilities. It presents a framework for improving the management models through the design and implementation of effective and high-quality MIS. So it is very important to the modem management of corporations. ERP （Enterprise Resource Planning） system is one of the core parts of MIS, which solves the matter of management model mainly. ERP is a popular method enabling the business processes required to compete with the globalization. The thesis cites SAP R/3 to introduce the general structure and function of ERP. Global Enterprise Resource Planning Implementation is increasingly becoming the successful choice of MIS.展开更多
Surface flashover is a gas-solid interface insulation failure that significantly jeopardises the secure operation of advanced electronic,electrical,and spacecraft applications.Despite the widespread application of num...Surface flashover is a gas-solid interface insulation failure that significantly jeopardises the secure operation of advanced electronic,electrical,and spacecraft applications.Despite the widespread application of numerous material modification and structure optimisation technologies aimed at enhancing surface flashover performance,the influence mechanisms of the present technologies have yet to be systematically discussed and summarised.This review aims to introduce various material modification technologies while demonstrating their influence mechanisms on flashover performances by establishing relationships among‘microscopic structure-mesoscopic charge transport-macroscopic insulation failure’.Moreover,it elucidates the effects of chemical structure on surface trap parameters and surface charge transport concerning flashover performance.The review categorises and presents structure optimisation technologies that govern electric field distribution.All identified technologies highlight that achieving a uniform tangential electric field and reducing the normal electric field can effectively enhance flashover performance.Finally,this review proposes recommendations encompassing mathematical,chemical,evaluation,and manufacturing technologies.This systematic summary of current technologies,their influence mechanisms,and associated advantages and disadvantages in improving surface insulation performance is anticipated to be a pivotal component in flashover and future dielectric theory.展开更多
Shanghai’s modern architectural heritage in the 19^(th) and early 20^(th) centuries is an essential aspect of modern Chinese architectural history because of its outstanding characteristics and well-preserved conditi...Shanghai’s modern architectural heritage in the 19^(th) and early 20^(th) centuries is an essential aspect of modern Chinese architectural history because of its outstanding characteristics and well-preserved conditions.Modern Shanghai architecture was transformed by the importation of Western structural technologies and materials in addition to their forms and institutions.After 100 years of development since 1843,there were over 100 important buildings in the Bund area by 1943.These buildings were built in different periods using the best available structural technologies.This study focuses on the technological dimension of modern Shanghai architecture.Based on an architectural survey and a literature investigation of the Bund buildings,this study explores the evolution of modern structural technologies in Shanghai by analysing the Bund buildings’key structural factors.The influences of the localisation and implementation of Western architecture’s building technologies in Shanghai were also analysed,including time of importation,characteristics and integration of local craftsmanship and materials.This study focuses on the method and analyses of architectural technology history from not only technological and historical perspectives,but also a social sciences perspective.展开更多
基金supported by the Key Program of the National Natural Science Foundation of China(Grant No.50539010)the Special Fund for Public Welfare Industry of the Ministry of Water Resources of China(Grant No.200801019)
文摘In conjunction with association rules for data mining, the connections between testing indices and strong and weak association rules were determined, and new derivative rules were obtained by further reasoning. Association rules were used to analyze correlation and check consistency between indices. This study shows that the judgment obtained by weak association rules or non-association rules is more accurate and more credible than that obtained by strong association rules. When the testing grades of two indices in the weak association rules are inconsistent, the testing grades of indices are more likely to be erroneous, and the mistakes are often caused by human factors. Clustering data mining technology was used to analyze the reliability of a diagnosis, or to perform health diagnosis directly. Analysis showed that the clustering results are related to the indices selected, and that if the indices selected are more significant, the characteristics of clustering results are also more significant, and the analysis or diagnosis is more credible. The indices and diagnosis analysis function produced by this study provide a necessary theoretical foundation and new ideas for the development of hydraulic metal structure health diagnosis technology.
基金supported by the National Natural Science Foundation of China under Grant No.61434006
文摘This paper presents a terahertz（THz）band-pass filter using ultra-precision machining technology based on Chebyshev filter prototype.This iris inductive window coupled waveguide filter was designed by using 8 resonant cavities with a center frequency of 345 GHz and a 7% bandwidth.The final design fulfills the desired specifications and presents the minimum insertion loss of 1.55 d B and the return loss of less than 15 d B at 345 GHz.The stop-band rejection is50 d B off the center frequency about 30 GHz,which means it has a good performance of high stop-band suppression.Compared with the recent development of THz filters,this filter possesses the characteristic of simple structure and is easy to machining.
文摘In recent years, China has stepped up its efforts to open its economy to the outside world, thus effectively promoting the sound development of the social economy and creating a good foundation for the development and expansion of the field of science and technology. As a result, a large number of new technologies have been developed and widely used by people in many fields with good results. Especially in the civil engineering industry, the continuous improvement of engineering construction technology has laid a solid foundation for the continuous improvement of civil engineering construction quality. At present, China's urbanization construction has been widely implemented, and the number of civil construction projects in various regions has gradually increased, which makes people put forward higher requirements on the construction technology level of construction projects. Steel structure is an important part in civil engineering projects. The construction effect of steel structure is often closely related to the construction quality of civil engineering projects, and it is also an important foundation for the sustainable and stable development of civil engineering industry. In view of this, this article mainly focuses on the comprehensive and in-depth research and analysis of steel structure construction technology in civil engineering construction, hoping to be helpful for the future good development of the civil engineering industry in our country.
文摘This paper briefs the current clean production and consumption levels of coal in China and the pollution harmbrought to the atmospheric environment, present status and orientation of clean coal technology development in Chinacoal industry, progress and perspective of clean coal power generation technology in China, as well as application andmarket of flue gas desulphurization technology in coal-fired power plants.[
基金supported by the National Key Research and Development Program of China(2019YFC1904800)the National Natural Science Foundation of China(72274105).
文摘Decarbonization and decontamination of the iron and steel industry(ISI),which contributes up to 15%to anthropogenic CO_(2) emissions(or carbon emissions)and significant proportions of air and water pollutant emissions in China,are challenged by the huge demand for steel.Carbon and pollutants often share common emission sources,indicating that emission reduction could be achieved synergistically.Here,we explored the inherent potential of measures to adjust feedstock composition and technological structure and to control the size of the ISI to achieve carbon emission reduction(CER)and pollution emission reduction(PER).We investigated five typical pollutants in this study,namely,petroleum hydrocarbon pollutants and chemical oxygen demand in wastewater,particulate matter,SO_(2),and NO_(x) in off gases,and examined synergies between CER and PER by employing cross elasticity for the period between 2022 and 2035.The results suggest that a reduction of 8.7%-11.7%in carbon emissions and 20%-31%in pollution emissions(except for particulate matter emissions)could be achieved by 2025 under a high steel scrap ratio(SSR)scenario.Here,the SSR and electric arc furnace(EAF)ratio serve critical roles in enhancing synergies between CER and PER(which vary with the type of pollutant).However,subject to a limited volume of steel scrap,a focused increase in the EAF ratio with neglection of the available supply of steel scrap to EAF facilities would lead to an increase carbon and pollution emissions.Although CER can be achieved through SSR and EAF ratio optimization,only when the crude steel production growth rate remains below 2.2%can these optimization measures maintain the emissions in 2030 at a similar level to that in 2021.Therefore,the synergistic effects between PER and CER should be considered when formulating a development route for the ISI in the future.
文摘Photonic crystals(PC)play an increasingly important role in anti-counterfeiting,sensors,displays,and other fields because they produce adjustable structural colors through optical manipulation of photonic stopbands.Flexible structural color materials(FSCMs)eliminate the requirement that traditional structures rely on hard substrates and the problem of poor mechanical quality caused by the stiffness of the building blocks.At the same time,different production technologies and materials provide FSCMs with different abilities to change color in response to stimulation.Therefore,they have attracted extensive attention.This paper summarizes the preparation strategy and variable structural colors of FSCMs.First,a series of preparation strategies for integrating materials with PC are summarized,including the assembly of colloidal spheres on flexible substrates,polymers,direct assembly based on polymers,and 3D printing.Subsequently,the variable structural colors of FSCMs with different stimuli,such as chemical stimuli,temperature,humidity,and mechanical stress,are described in detail.Finally,several potential directions for FSCMs manufacturing and application are introduced,and its prospects and challenges are discussed.It is believed that it will be valuable to promote the use of flexible optical materials.
基金Under the auspices of Major Project of National Social Science Foundation of China(No.13&ZD027)National Natural Science Foundation of China(No.41201128,71433008)
文摘Based on patent cooperation data,this study used a range of city network analysis approaches in order to explore the structure of the Chinese city network which is driven by technological knowledge flows.The results revealed the spatial structure,composition structure,hierarchical structure,group structure,and control structure of Chinese city network,as well as its dynamic factors.The major findings are:1) the spatial pattern presents a diamond structure,in which Wuhan is the central city;2) although the invention patent knowledge network is the main part of the broader inter-city innovative cooperation network,it is weaker than the utility model patent;3) as the senior level cities,Beijing,Shanghai and the cities in the Zhujiang(Pearl) River Delta Region show a strong capability of both spreading and controlling technological knowledge;4) whilst a national technology alliance has preliminarily formed,regional alliances have not been adequately established;5) even though the cooperation level amongst weak connection cities is not high,such cities still play an important role in the network as a result of their location within ′structural holes′ in the network;and 6) the major driving forces facilitating inter-city technological cooperation are geographical proximity,hierarchical proximity and technological proximity.
文摘Management Information System provides an effective way for enterprises to improve their competitive abilities. It presents a framework for improving the management models through the design and implementation of effective and high-quality MIS. So it is very important to the modem management of corporations. ERP （Enterprise Resource Planning） system is one of the core parts of MIS, which solves the matter of management model mainly. ERP is a popular method enabling the business processes required to compete with the globalization. The thesis cites SAP R/3 to introduce the general structure and function of ERP. Global Enterprise Resource Planning Implementation is increasingly becoming the successful choice of MIS.
基金National Natural Science Foundation of China,Grant/Award Number:52307166Natural Science Foundation of Heilongjiang Province,Grant/Award Number:LH2023E085+1 种基金Natural Science Foundation of Shandong Province,Grant/Award Number:ZR2023QE072State Key Laboratory of Electrical Insulation and Power Equipment,Grant/Award Number:EIPE23206。
文摘Surface flashover is a gas-solid interface insulation failure that significantly jeopardises the secure operation of advanced electronic,electrical,and spacecraft applications.Despite the widespread application of numerous material modification and structure optimisation technologies aimed at enhancing surface flashover performance,the influence mechanisms of the present technologies have yet to be systematically discussed and summarised.This review aims to introduce various material modification technologies while demonstrating their influence mechanisms on flashover performances by establishing relationships among‘microscopic structure-mesoscopic charge transport-macroscopic insulation failure’.Moreover,it elucidates the effects of chemical structure on surface trap parameters and surface charge transport concerning flashover performance.The review categorises and presents structure optimisation technologies that govern electric field distribution.All identified technologies highlight that achieving a uniform tangential electric field and reducing the normal electric field can effectively enhance flashover performance.Finally,this review proposes recommendations encompassing mathematical,chemical,evaluation,and manufacturing technologies.This systematic summary of current technologies,their influence mechanisms,and associated advantages and disadvantages in improving surface insulation performance is anticipated to be a pivotal component in flashover and future dielectric theory.
文摘Shanghai’s modern architectural heritage in the 19^(th) and early 20^(th) centuries is an essential aspect of modern Chinese architectural history because of its outstanding characteristics and well-preserved conditions.Modern Shanghai architecture was transformed by the importation of Western structural technologies and materials in addition to their forms and institutions.After 100 years of development since 1843,there were over 100 important buildings in the Bund area by 1943.These buildings were built in different periods using the best available structural technologies.This study focuses on the technological dimension of modern Shanghai architecture.Based on an architectural survey and a literature investigation of the Bund buildings,this study explores the evolution of modern structural technologies in Shanghai by analysing the Bund buildings’key structural factors.The influences of the localisation and implementation of Western architecture’s building technologies in Shanghai were also analysed,including time of importation,characteristics and integration of local craftsmanship and materials.This study focuses on the method and analyses of architectural technology history from not only technological and historical perspectives,but also a social sciences perspective.
