The channel lateral pocket or halo region of NMOSFET characterized by interface state R G current of a forward gated diode has been investigated numerically for the first time.The result of numerical analysis demons...The channel lateral pocket or halo region of NMOSFET characterized by interface state R G current of a forward gated diode has been investigated numerically for the first time.The result of numerical analysis demonstrates that the effective surface doping concentration and the interface state density of the pocket or halo region are interface states R G current peak position dependent and amplitude dependent,respectively.It can be expressed quantitatively according to the device physics knowledge,thus,the direct characterization of the interface state density and the effective surface doping concentration of the pocket or halo becomes very easy.展开更多
Vascular anomalies constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the practice of medicine. The clinical presentations are extremely protean and can range from an a...Vascular anomalies constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the practice of medicine. The clinical presentations are extremely protean and can range from an asymptomatic birthmark to fulminant。展开更多
The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, t...The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, the state of the cenotic populations of the species was assessed, during the 2012-2018 years studied 15 cenopopulations different ecological-phytocenotic conditions in Uzbekistan.展开更多
This paper studies two-dimensional analysis of the surface state effect on current gain for a 4H-SiC bipolar junction transistor (BJT). Simulation results indicate the mechanism of current gain degradation, which is...This paper studies two-dimensional analysis of the surface state effect on current gain for a 4H-SiC bipolar junction transistor (BJT). Simulation results indicate the mechanism of current gain degradation, which is surface Fermi level pinning leading to a strong downward bending of the energy bands to form the channel of surface electron recombination current. The experimental results are well-matched with the simulation, which is modeled by exponential distributions of the interface state density replacing the single interface state trap. Furthermore, the simulation reveals that the oxide quality of the base emitter junction interface is very important for 4H-SiC BJT performance.展开更多
The boost converter feeding a constant power load (CPL) is a non-minimum phase system that is prone to the destabilizing effects of the negative incremental resistance of the CPL and presents a major challenge in the ...The boost converter feeding a constant power load (CPL) is a non-minimum phase system that is prone to the destabilizing effects of the negative incremental resistance of the CPL and presents a major challenge in the design of stabilizing controllers. A PWM-based current-sensorless robust sliding mode controller is developed that requires only the measurement of the output voltage. An extended state observer is developed to estimate a lumped uncertainty signal that comprises the uncertain load power and the input voltage, the converter parasitics, the component uncertainties and the estimation of the derivative of the output voltage needed in the implementation of the controller. A linear sliding surface is used to derive the controller, which is simple in its design and yet exhibits excellent features in terms of robustness to external disturbances, parameter uncertainties, and parasitics despite the absence of the inductor’s current feedback. The robustness of the controller is validated by computer simulations.展开更多
The purposes of this study are to assess the COVID-19 pandemic’s impacts on the dairy industries in China and the United States and to derive policy recommendations for enhancing the diary industries’resilience to p...The purposes of this study are to assess the COVID-19 pandemic’s impacts on the dairy industries in China and the United States and to derive policy recommendations for enhancing the diary industries’resilience to pandemics and other market shocks.Specifically,data from the two nations are used to analyze and compare the mechanisms through which the pandemic has affected their dairy industries and to discuss potential lessons from their experiences.The findings suggest that this pandemic has heavily affected the dairy industries in both China and the United States through similar mechanisms,such as decreased farmgate milk prices,disruption and difficulties of moving milk within the supply chains,worker shortages,increased production costs,and lack of operating capital.There were also significant differences in the affecting mechanisms between the two nations,including transportation difficulties from widespread road closures and significant reduction in holiday sales of dairy products in China,and the shutdown of many dairy processors in the United States due to the closing of schools,restaurants,and hotels.While government financial reliefs are highly needed to help many dairy farms and processors survive this pandemic in the short term,the dairy industries and governments need to work together to develop long-term strategies and policies to balance the industries’efficiency and flexibility,product specialization and diversification,supply chain integration and local food systems,and market mechanisms and policy regulations and interventions.展开更多
BACKGROUND:On July 21, 2009, the Medical Council of India officially recognized the specialty of emergency medicine in India. The city of Chennai with over six and a half million people is the fourth largest on the s...BACKGROUND:On July 21, 2009, the Medical Council of India officially recognized the specialty of emergency medicine in India. The city of Chennai with over six and a half million people is the fourth largest on the subcontinent and has already been a prominent city of interest in the specialty's development. However, there is no standardization of the resources found in the city's emergency departments. This study was to survey the equipment, training, and certification of Chennai area emergency departments and their staff. METHODS:We conducted a cross-sectional survey of emergency department staff from 38 Chennai area hospitals. The survey instrument contained 44 questions pertaining to hospital demographics, staff training and certification, and ED equipment and supplies. The items on the survey were specifically chosen to represent only the most basic and common resources necessary to practise emergency medicine. RESULTS: The survey found a majority of hospitals are privately operated but there is a wide range in terms of size and volume of patients. A minority of both doctors and nurses are certified in BLS, ACLS, PALS, and ATLS. While almost all departments surveyed had the basic code medications, a number of basic equipment items were lacking from a large percentage of the EDs surveyed. CONCLUSION:The newly established EP community in Chennai will have the responsibility to establish standards for both training and resources so that the specialty may grow and provide a higher standard of emergency care moving into the future.展开更多
Mining industry has significantly contributed to the prosperity of the nation with economic growth, whereas mining operation has caused Acid Mine Drainage (AMD) with the abandonment of mines. As some researchers sugge...Mining industry has significantly contributed to the prosperity of the nation with economic growth, whereas mining operation has caused Acid Mine Drainage (AMD) with the abandonment of mines. As some researchers suggest, the history of AMD is, generally, affected by the change in not only mining industry but also in social and economic conditions. Thus, historical analysis is an effective way to find the key factors of AMD. In this study, in order to find the key factors of AMD, we examine the history of the United States (U.S.) and South Africa, where their economy had been developed owing to the large-scale mining, based on the findings in the previous studies. The results indicated that the abandoned mines due to the economic depression triggered AMD in the U.S. and South Africa. While the U.S. had progressively adopted anti-AMD methods in terms of prevention, prediction, and remediation (PPR) as a comprehensive approach, especially since the 1970s onwards because of the rise of environmental consciousness as well as strict regulations, South Africa is at the early stage of implementing the regulations following PPR. The public attention should be directed to environmental conservation in addition to the implementation of the regulations in South Africa. The improvement in socio-economic conditions is, additionally, necessary for the rise of environmental consciousness in South Africa in the light of the three pillars of sustainable development: social, economic, and environmental elements.展开更多
1.Introduction In recent years,China's semiconductor equipment industry has made considerable progress,some key equipment have been developed,achieving a revolutionary breakthrough.Meanwhile,a great number of dome...1.Introduction In recent years,China's semiconductor equipment industry has made considerable progress,some key equipment have been developed,achieving a revolutionary breakthrough.Meanwhile,a great number of domestic equipment have been applied to large mass production lines,indicating new progress in industrialization.From the policy perspective,the state has continuously introduced policies to support the localization of the semiconductor industry,and has invested more than 100 billion yuan to boost the development of the semiconductor industry chain since 2014.展开更多
The principle of minimum dissipation rate is applied to tokamak plasmas with energy and helicity balances imposed as two constraints. The analytical solution on toroidal current distribution are derived from the resul...The principle of minimum dissipation rate is applied to tokamak plasmas with energy and helicity balances imposed as two constraints. The analytical solution on toroidal current distribution are derived from the resulting Euler-Lagrangian equation. Three typical forms of current profiles are found for low-aspect-ratio tokamaks like NSTX. One of them decreases with r on equatorial plane, the second peaks in the inner half part on equatorial plane and the third may have a hole or reverse in the central part.展开更多
The Chinese Proficiency Test(HSK)is a standardized test on Chinese language skills which has been widely introduced both in and outside China and has been playing an important role in the spread of Chinese learning al...The Chinese Proficiency Test(HSK)is a standardized test on Chinese language skills which has been widely introduced both in and outside China and has been playing an important role in the spread of Chinese learning all over the world.In 2003 Bulgaria hosted a beginner level HSK exam,which made it the first location to hold a Chinese language proficiency test on the Balkan Peninsula and ever since it has been very successful.The current paper provides a research on the current state of the Chinese Proficiency Test(HSK)аt the Confucius Institute in Sofia,Bulgaria,analyzes the factors related to the promotion of the Chinese Proficiency Test(HSK)and on this basis presents a few feasible recommendations to the benefit of the Chinese Proficiency Test(HSK).展开更多
Core indicators of China’s natural gas industry in 2016In 2016,China produced 132.82 bcm of natural gas and 1.61bcm of coal-to-gas,production amounts that were 1.5%and 15.8%higher than those of the previous year,resp...Core indicators of China’s natural gas industry in 2016In 2016,China produced 132.82 bcm of natural gas and 1.61bcm of coal-to-gas,production amounts that were 1.5%and 15.8%higher than those of the previous year,respectively.The imported gas volume was 38.34bcm through pipeline(up 9.0%from the previous year)and 33.74 bcm via LNG facilities(up 30.6%from展开更多
An announcement was made on November 4, 1994, on making the China National Nonferrous Industry Corporation one of the three State holding corporations for experiment at a national conference on experimenting on modern...An announcement was made on November 4, 1994, on making the China National Nonferrous Industry Corporation one of the three State holding corporations for experiment at a national conference on experimenting on modern enterprises sponsored by the State Council. The appearance of State holding corporations is the result of China’s deepening economic restructuring and an important and integral part of deepening enterprise reform.展开更多
China has many lakes, marshlands and rivers. Due to their uneven geographical distribution and varied degrees of salinity, their exploitable freshwater resources are limited. In the wake of the highspeed growth of nat...China has many lakes, marshlands and rivers. Due to their uneven geographical distribution and varied degrees of salinity, their exploitable freshwater resources are limited. In the wake of the highspeed growth of national economy in recent years, human infringement upon their natural settings has been increasingly intense, leading to the degeneration of China's lacustrine ecosystems and the degradation of their surrounding environments. Lakes are shrinking and becoming more saline. In arid and semi-arid inland areas, some of them have even disappeared. In addition, lake water pollution and eutrophication in densely populated areas are getting worse, resulting in serious water shortages in some places. Silt deposition in lake basins, water surface shrinkage caused by hectic and irrational reclamation for farmland, the prevalence of flooding and water-logging calamities and ecosystem depletion caused by predatory exploitation of fishery resources, all of these have become restrictive factors in regional sustainable development. The author of this article suggests measures for the protection and sustainable exploitation of limnetic settings in China.展开更多
Based on the review of the papers and other related material submitted to the conference, the status quo and developmental trends of geocryology is briefly discussed.
The paper viewed the current problem that state-owned enterprises in northeast industry base hadn't technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction f...The paper viewed the current problem that state-owned enterprises in northeast industry base hadn't technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction from abroad. Operational evaluation method and index criteria system of enterprises technology innovation ability were put forward in this paper, different enterprises may revise the model according to their actual situations to evaluate the enterprise technological innovation ability scientifically and quickly. The findings will be helpful to correlative departments to formulate the related policies and also has important theoretical and practical value in technological innovation project of enterprise.展开更多
Objective: To investigate the research hotspots and development trends of Chinese geriatric medicine by analyzing the high-frequency keywords, core authors, research institutions and their collaborations in papers pub...Objective: To investigate the research hotspots and development trends of Chinese geriatric medicine by analyzing the high-frequency keywords, core authors, research institutions and their collaborations in papers published in the Chinese Journal of Geriatrics.Methods: Bibliometric methods and information visualization software(CiteSpace Ⅲ) were used to analyze the following 3 aspects: keywords, institutions and authors.Results: Overall, the number of papers published in the Chinese Journal of Geriatrics grew between 1994 and 2015. The top 3 institutions with the greatest numbers of published papers were Beijing Hospital,People's Liberation Army General Hospital and the Second Xiangya Hospital of Central South University.The authors with high productivity were Pulin Yu, Jianye Wang and Xiaoying Li. The terms "Diabetes","hypertension" and "myocardial infarction" were hotspot words that drew sustained attention in this field.Conclusions: Research on geriatric medicine is growing steadily in China. Hospitals and teaching hospitals are major contributors to publications. The collaboration of authors is more common within the same institutions or in the same regions. Clinical research is still the focus of current research. In the future, basic research should be strengthened, and collaborations between different institutions and regions should be promoted to achieve coordinated and integrated development in Chinese geriatric medicine.展开更多
Because of the end effect, a linear induction motor (LIM) runs in an asymmetrical state even though the winding of each phase is symmetric. Based on the basic principle of the LIM, a new approach was proposed to cal...Because of the end effect, a linear induction motor (LIM) runs in an asymmetrical state even though the winding of each phase is symmetric. Based on the basic principle of the LIM, a new approach was proposed to calculate the thrust of the LIM using the instantaneous current value. A three-phase LIM model with 12 slots and a singlelayer winding was designed to validate this method. The experiments show that when the current is small, the calculated results basically agree with the experiments. The agreement becomes worse with the increase of the current because of the saturation of the primary iron core. The proposed formula is suitable when the iron core of the LIM primary is in an unsaturated state.展开更多
With a new approach,the general current expressions of two typical second order catalytic reactions at microelectrodes are obtained.This allows the study of fast chemical reactions and systems where the reactants are ...With a new approach,the general current expressions of two typical second order catalytic reactions at microelectrodes are obtained.This allows the study of fast chemical reactions and systems where the reactants are present in similar concentrations.展开更多
文摘The channel lateral pocket or halo region of NMOSFET characterized by interface state R G current of a forward gated diode has been investigated numerically for the first time.The result of numerical analysis demonstrates that the effective surface doping concentration and the interface state density of the pocket or halo region are interface states R G current peak position dependent and amplitude dependent,respectively.It can be expressed quantitatively according to the device physics knowledge,thus,the direct characterization of the interface state density and the effective surface doping concentration of the pocket or halo becomes very easy.
文摘Vascular anomalies constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the practice of medicine. The clinical presentations are extremely protean and can range from an asymptomatic birthmark to fulminant。
文摘The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, the state of the cenotic populations of the species was assessed, during the 2012-2018 years studied 15 cenopopulations different ecological-phytocenotic conditions in Uzbekistan.
文摘This paper studies two-dimensional analysis of the surface state effect on current gain for a 4H-SiC bipolar junction transistor (BJT). Simulation results indicate the mechanism of current gain degradation, which is surface Fermi level pinning leading to a strong downward bending of the energy bands to form the channel of surface electron recombination current. The experimental results are well-matched with the simulation, which is modeled by exponential distributions of the interface state density replacing the single interface state trap. Furthermore, the simulation reveals that the oxide quality of the base emitter junction interface is very important for 4H-SiC BJT performance.
文摘The boost converter feeding a constant power load (CPL) is a non-minimum phase system that is prone to the destabilizing effects of the negative incremental resistance of the CPL and presents a major challenge in the design of stabilizing controllers. A PWM-based current-sensorless robust sliding mode controller is developed that requires only the measurement of the output voltage. An extended state observer is developed to estimate a lumped uncertainty signal that comprises the uncertain load power and the input voltage, the converter parasitics, the component uncertainties and the estimation of the derivative of the output voltage needed in the implementation of the controller. A linear sliding surface is used to derive the controller, which is simple in its design and yet exhibits excellent features in terms of robustness to external disturbances, parameter uncertainties, and parasitics despite the absence of the inductor’s current feedback. The robustness of the controller is validated by computer simulations.
基金The authors would like to thank the Vermont Agricultural Experiment Station at the University of Vermont,USA,and earmarked fund for China Agriculture Research System(CARS-36)for financial support of this study.
文摘The purposes of this study are to assess the COVID-19 pandemic’s impacts on the dairy industries in China and the United States and to derive policy recommendations for enhancing the diary industries’resilience to pandemics and other market shocks.Specifically,data from the two nations are used to analyze and compare the mechanisms through which the pandemic has affected their dairy industries and to discuss potential lessons from their experiences.The findings suggest that this pandemic has heavily affected the dairy industries in both China and the United States through similar mechanisms,such as decreased farmgate milk prices,disruption and difficulties of moving milk within the supply chains,worker shortages,increased production costs,and lack of operating capital.There were also significant differences in the affecting mechanisms between the two nations,including transportation difficulties from widespread road closures and significant reduction in holiday sales of dairy products in China,and the shutdown of many dairy processors in the United States due to the closing of schools,restaurants,and hotels.While government financial reliefs are highly needed to help many dairy farms and processors survive this pandemic in the short term,the dairy industries and governments need to work together to develop long-term strategies and policies to balance the industries’efficiency and flexibility,product specialization and diversification,supply chain integration and local food systems,and market mechanisms and policy regulations and interventions.
文摘BACKGROUND:On July 21, 2009, the Medical Council of India officially recognized the specialty of emergency medicine in India. The city of Chennai with over six and a half million people is the fourth largest on the subcontinent and has already been a prominent city of interest in the specialty's development. However, there is no standardization of the resources found in the city's emergency departments. This study was to survey the equipment, training, and certification of Chennai area emergency departments and their staff. METHODS:We conducted a cross-sectional survey of emergency department staff from 38 Chennai area hospitals. The survey instrument contained 44 questions pertaining to hospital demographics, staff training and certification, and ED equipment and supplies. The items on the survey were specifically chosen to represent only the most basic and common resources necessary to practise emergency medicine. RESULTS: The survey found a majority of hospitals are privately operated but there is a wide range in terms of size and volume of patients. A minority of both doctors and nurses are certified in BLS, ACLS, PALS, and ATLS. While almost all departments surveyed had the basic code medications, a number of basic equipment items were lacking from a large percentage of the EDs surveyed. CONCLUSION:The newly established EP community in Chennai will have the responsibility to establish standards for both training and resources so that the specialty may grow and provide a higher standard of emergency care moving into the future.
文摘Mining industry has significantly contributed to the prosperity of the nation with economic growth, whereas mining operation has caused Acid Mine Drainage (AMD) with the abandonment of mines. As some researchers suggest, the history of AMD is, generally, affected by the change in not only mining industry but also in social and economic conditions. Thus, historical analysis is an effective way to find the key factors of AMD. In this study, in order to find the key factors of AMD, we examine the history of the United States (U.S.) and South Africa, where their economy had been developed owing to the large-scale mining, based on the findings in the previous studies. The results indicated that the abandoned mines due to the economic depression triggered AMD in the U.S. and South Africa. While the U.S. had progressively adopted anti-AMD methods in terms of prevention, prediction, and remediation (PPR) as a comprehensive approach, especially since the 1970s onwards because of the rise of environmental consciousness as well as strict regulations, South Africa is at the early stage of implementing the regulations following PPR. The public attention should be directed to environmental conservation in addition to the implementation of the regulations in South Africa. The improvement in socio-economic conditions is, additionally, necessary for the rise of environmental consciousness in South Africa in the light of the three pillars of sustainable development: social, economic, and environmental elements.
文摘1.Introduction In recent years,China's semiconductor equipment industry has made considerable progress,some key equipment have been developed,achieving a revolutionary breakthrough.Meanwhile,a great number of domestic equipment have been applied to large mass production lines,indicating new progress in industrialization.From the policy perspective,the state has continuously introduced policies to support the localization of the semiconductor industry,and has invested more than 100 billion yuan to boost the development of the semiconductor industry chain since 2014.
文摘The principle of minimum dissipation rate is applied to tokamak plasmas with energy and helicity balances imposed as two constraints. The analytical solution on toroidal current distribution are derived from the resulting Euler-Lagrangian equation. Three typical forms of current profiles are found for low-aspect-ratio tokamaks like NSTX. One of them decreases with r on equatorial plane, the second peaks in the inner half part on equatorial plane and the third may have a hole or reverse in the central part.
文摘The Chinese Proficiency Test(HSK)is a standardized test on Chinese language skills which has been widely introduced both in and outside China and has been playing an important role in the spread of Chinese learning all over the world.In 2003 Bulgaria hosted a beginner level HSK exam,which made it the first location to hold a Chinese language proficiency test on the Balkan Peninsula and ever since it has been very successful.The current paper provides a research on the current state of the Chinese Proficiency Test(HSK)аt the Confucius Institute in Sofia,Bulgaria,analyzes the factors related to the promotion of the Chinese Proficiency Test(HSK)and on this basis presents a few feasible recommendations to the benefit of the Chinese Proficiency Test(HSK).
文摘Core indicators of China’s natural gas industry in 2016In 2016,China produced 132.82 bcm of natural gas and 1.61bcm of coal-to-gas,production amounts that were 1.5%and 15.8%higher than those of the previous year,respectively.The imported gas volume was 38.34bcm through pipeline(up 9.0%from the previous year)and 33.74 bcm via LNG facilities(up 30.6%from
文摘An announcement was made on November 4, 1994, on making the China National Nonferrous Industry Corporation one of the three State holding corporations for experiment at a national conference on experimenting on modern enterprises sponsored by the State Council. The appearance of State holding corporations is the result of China’s deepening economic restructuring and an important and integral part of deepening enterprise reform.
文摘China has many lakes, marshlands and rivers. Due to their uneven geographical distribution and varied degrees of salinity, their exploitable freshwater resources are limited. In the wake of the highspeed growth of national economy in recent years, human infringement upon their natural settings has been increasingly intense, leading to the degeneration of China's lacustrine ecosystems and the degradation of their surrounding environments. Lakes are shrinking and becoming more saline. In arid and semi-arid inland areas, some of them have even disappeared. In addition, lake water pollution and eutrophication in densely populated areas are getting worse, resulting in serious water shortages in some places. Silt deposition in lake basins, water surface shrinkage caused by hectic and irrational reclamation for farmland, the prevalence of flooding and water-logging calamities and ecosystem depletion caused by predatory exploitation of fishery resources, all of these have become restrictive factors in regional sustainable development. The author of this article suggests measures for the protection and sustainable exploitation of limnetic settings in China.
文摘Based on the review of the papers and other related material submitted to the conference, the status quo and developmental trends of geocryology is briefly discussed.
文摘The paper viewed the current problem that state-owned enterprises in northeast industry base hadn't technologies of their own intellectual property right, whose sources mainly depended on imitation and introduction from abroad. Operational evaluation method and index criteria system of enterprises technology innovation ability were put forward in this paper, different enterprises may revise the model according to their actual situations to evaluate the enterprise technological innovation ability scientifically and quickly. The findings will be helpful to correlative departments to formulate the related policies and also has important theoretical and practical value in technological innovation project of enterprise.
基金supported and funded by the National Natural Science Foundation of China(No.71403155)supported by the Shanxi Federation of Social Science Circles(No.SSKLZDKT2014084)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2017SY043)
文摘Objective: To investigate the research hotspots and development trends of Chinese geriatric medicine by analyzing the high-frequency keywords, core authors, research institutions and their collaborations in papers published in the Chinese Journal of Geriatrics.Methods: Bibliometric methods and information visualization software(CiteSpace Ⅲ) were used to analyze the following 3 aspects: keywords, institutions and authors.Results: Overall, the number of papers published in the Chinese Journal of Geriatrics grew between 1994 and 2015. The top 3 institutions with the greatest numbers of published papers were Beijing Hospital,People's Liberation Army General Hospital and the Second Xiangya Hospital of Central South University.The authors with high productivity were Pulin Yu, Jianye Wang and Xiaoying Li. The terms "Diabetes","hypertension" and "myocardial infarction" were hotspot words that drew sustained attention in this field.Conclusions: Research on geriatric medicine is growing steadily in China. Hospitals and teaching hospitals are major contributors to publications. The collaboration of authors is more common within the same institutions or in the same regions. Clinical research is still the focus of current research. In the future, basic research should be strengthened, and collaborations between different institutions and regions should be promoted to achieve coordinated and integrated development in Chinese geriatric medicine.
基金supported by the National Natural Science Foundation of China (Nos. 50588201,50672078, and 50872116)the National Basic Research Program (973 program, No. 2007CB616906)+1 种基金the Australian Research Council (Grant No. DP0559872 and DP0881739)the PCSIRT of the Ministry of Education of China (No. IRT0751)
文摘Because of the end effect, a linear induction motor (LIM) runs in an asymmetrical state even though the winding of each phase is symmetric. Based on the basic principle of the LIM, a new approach was proposed to calculate the thrust of the LIM using the instantaneous current value. A three-phase LIM model with 12 slots and a singlelayer winding was designed to validate this method. The experiments show that when the current is small, the calculated results basically agree with the experiments. The agreement becomes worse with the increase of the current because of the saturation of the primary iron core. The proposed formula is suitable when the iron core of the LIM primary is in an unsaturated state.
文摘With a new approach,the general current expressions of two typical second order catalytic reactions at microelectrodes are obtained.This allows the study of fast chemical reactions and systems where the reactants are present in similar concentrations.