A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distri...A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distribution obtained through approximating the input output function of the SI circuit by conventional wavelet collocation method.In practical applications,the proposed method is a general purpose approach,by which both the small signal effect and the large signal effect are modeled in a unified formulation to ease the process of modeling and simulation.Compared with the published modeling approaches,the proposed nonlinear auto companding method works more efficiently not only in controlling the error distribution but also in reducing the modeling errors.To demonstrate the promising features of the proposed method,several SI circuits are employed as examples to be modeled and simulated.展开更多
Frame aggregation is a wireless link optimization mechanism that aims to reduce transmission overheads by sending multiple flames as the payload of a single MAC flame. It is considered as one of the most efficient met...Frame aggregation is a wireless link optimization mechanism that aims to reduce transmission overheads by sending multiple flames as the payload of a single MAC flame. It is considered as one of the most efficient methods to improve the wireless channel utilization and the throughput of wireless networks. The static assignment of frame aggregation parameters can result in delay penalties due to variations in traffic type. We propose a frame aggregation scheme which is based on dyn- amic pricing and queue scheduling for a multi- traffic scenario. The scheme adopts a dynamic differential pricing scheme for different types of traffic. Meanwhile, it polls buffer queues in accordance with the optimal aggregation wei- ght factors to maximise the network revenue. Simulation results indicate that the proposed frame aggregation scheme can effectively improve the network revenue and the average throughput, while guaranteeing the delay requirements of all types of traffic.展开更多
This paper deals with the influence of phase modulated synthetic jet on the aerodynamics of the hump in a closed test section Of the Eiffel-type wind tunnel. Three experimental methods of measurement techniques of thi...This paper deals with the influence of phase modulated synthetic jet on the aerodynamics of the hump in a closed test section Of the Eiffel-type wind tunnel. Three experimental methods of measurement techniques of this phenomenon were used： the pressure profile using the Kiel total pressure probe, the velocity profile using the CTA （constant temperature anemometry） probe and the visualization of the flow field using the hot film and the thermo camera, The experimental results with and without the influence of the synthetic jet were compared, as well the impact of the phase shift of the neighbouring synthetic jets. As a reference case, the flow around the hump without the influence of the synthetic jet was selected. The results of the measurement are presented in figures and compared.展开更多
With the emergence of the concept of cultural routes, researchers have increasingly turned their attention to the sustainable development of tourism along cultural routes. The needs for community participation and the...With the emergence of the concept of cultural routes, researchers have increasingly turned their attention to the sustainable development of tourism along cultural routes. The needs for community participation and the ongoing provision of benefits of stakeholders are characteristics of cultural routes. Therefore, the importance of cooperative relations and systematic development among stakeholders in tourism activities along cultural routes has become a subject of interest. This paper selects local government, tourism enterprises and local community residents, all of which play a key role in the Ancient Tea Horse Road cultural route in the south of Yunnan, as the main stakeholders. We use game theory to construct a model to trace interactions between local government and tourism enterprises, between tourism enterprises and community residents, and between local government and community residents. The paper then analyzes the different interests of the three parties and key factors that influence them in the game process. This provided a certain scientific basis for the win-win decisions regarding tourism development made by the three parties. Our results show that the final decision choices of the three parties depend on the initial payoff matrix of the game, and the influence of key parameters. When making decisions about tourism, the government should respect the wishes of local residents, strengthen protections of local traditions, manage the unreasonable behavior of tourism enterprises as they develop tourism, and develop appropriate penalties for violations of regulations. When tourism enterprises carry out tourism development, they should let community residents take the initiative and fully participate in tourism activities, and be sure that income from tourism is fed back to local residents, to ensure that tourism is mutually beneficial. The study shows that conflicts among the three parties originated mainly from differences in interests, but that the three parties also shared common interests. With a goal of coordinating interests, we can establish relevant mechanisms, follow the principle of interest realization, attach importance to supervision and management, strengthen community participation and decision-making, and realize win-win results for the three parties.展开更多
The oxygen reduction reaction (ORR) is the cornerstone reaction of the cathode in metal±air batteries;however,slow kinetics requires high-performance catalysts to promote the reaction.Polyphthalocyanine (PPc) has...The oxygen reduction reaction (ORR) is the cornerstone reaction of the cathode in metal±air batteries;however,slow kinetics requires high-performance catalysts to promote the reaction.Polyphthalocyanine (PPc) has a typical chemical cross-linking structure and uniformly dispersed metal active sites,but its poor activity and conductivity limit its applications as an ORR catalyst.Herein,a manageable and convenient strategy is proposed to synthesize ternary ORR catalysts through the low-temperature pyrolysis of Fe PPc.The optimal catalyst,Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5,exhibits excellent ORR activity in alkaline solution with a half-wave potential of 0.90 V,which is significantly higher than that of commercial 20%Pt/C (0.84 V).Electrochemical tests and extended X-ray absorption fine structure spectroscopy reveal that the superior ORR activity of Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 could be ascribed to the balance of its ternary components(i.e.,Fe_(3)O_(4),Fe_(3)N,and Fe-N;species).A Zn±air battery incorporating Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 as an air cathodic catalyst delivers a high open-circuit voltage and peak power density.During galvanostatic discharge,the battery demonstrates a specific capacity of 815.7 mA h g^(-1).The facile strategy of using PPc to develop high-performance composite electrocatalysts may be expanded to develop new types of catalysts in the energy field.展开更多
Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model o...Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model of metal hot-electron power generation is built.Free electron model of Sommerfeld is used to describe the movement of electrons in metal.According to the different width of potential barriers,two models are built.One assumes that electrons move from one metal to another mainly by moving over the potential barrier as the barrier is wide enough.The other assumes that the potential barrier is so narrow that electrons mainly move through the potential barrier by tunnel effect.The first model is analyzed and proved strictly,including the building of model,the calculation of open-circuit voltage and the drawing of volt-ampere characteristic curve.The second model is analysed simply.This paper shows that power generation by metal hot-electron is possible based on the theory and can provide reference for researching in power generation of metal hot-electron.展开更多
Histone modifications have been widely elucidated to play vital roles in gene regulation and cell identity. The Roadmap Epigenomics Consortium generated a reference catalog of several key histone modifications across ...Histone modifications have been widely elucidated to play vital roles in gene regulation and cell identity. The Roadmap Epigenomics Consortium generated a reference catalog of several key histone modifications across 〉lOOs of human cell types and tissues. Decoding these epJgenomes into functional regulatory elements is a challenging task in computational biology. To this end, we adopted a differential chromatin modification analysis framework to comprehensively determine and characterize cell type-specific regulatory elements （CSREs） and their histone modification codes in the human epigenomes of five histone modifications across 127 tissues or cell types. The CSREs show significant relevance with cell type-specific biological functions and diseases and cell identity. Clustering of CSREs with their specificity signals reveals distinct histone codes, demonstrating the diversity of functional roles of CSREs within the same cell or tissue. Last but not least, dynamics of CSREs from close cell types or tissues can give a detailed view of developmental processes such as normal tissue development and cancer occurrence.展开更多
文摘A wavelet collocation method with nonlinear auto companding is proposed for behavioral modeling of switched current circuits.The companding function is automatically constructed according to the initial error distribution obtained through approximating the input output function of the SI circuit by conventional wavelet collocation method.In practical applications,the proposed method is a general purpose approach,by which both the small signal effect and the large signal effect are modeled in a unified formulation to ease the process of modeling and simulation.Compared with the published modeling approaches,the proposed nonlinear auto companding method works more efficiently not only in controlling the error distribution but also in reducing the modeling errors.To demonstrate the promising features of the proposed method,several SI circuits are employed as examples to be modeled and simulated.
基金the National Natural Science Foundation of Chinaunder Grants No.61072068,No.61201137the State Key Program of National Natural Science Foundation of China under Grant No.61231008the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MEST) under Grant No.2010-0018116
文摘Frame aggregation is a wireless link optimization mechanism that aims to reduce transmission overheads by sending multiple flames as the payload of a single MAC flame. It is considered as one of the most efficient methods to improve the wireless channel utilization and the throughput of wireless networks. The static assignment of frame aggregation parameters can result in delay penalties due to variations in traffic type. We propose a frame aggregation scheme which is based on dyn- amic pricing and queue scheduling for a multi- traffic scenario. The scheme adopts a dynamic differential pricing scheme for different types of traffic. Meanwhile, it polls buffer queues in accordance with the optimal aggregation wei- ght factors to maximise the network revenue. Simulation results indicate that the proposed frame aggregation scheme can effectively improve the network revenue and the average throughput, while guaranteeing the delay requirements of all types of traffic.
文摘This paper deals with the influence of phase modulated synthetic jet on the aerodynamics of the hump in a closed test section Of the Eiffel-type wind tunnel. Three experimental methods of measurement techniques of this phenomenon were used： the pressure profile using the Kiel total pressure probe, the velocity profile using the CTA （constant temperature anemometry） probe and the visualization of the flow field using the hot film and the thermo camera, The experimental results with and without the influence of the synthetic jet were compared, as well the impact of the phase shift of the neighbouring synthetic jets. As a reference case, the flow around the hump without the influence of the synthetic jet was selected. The results of the measurement are presented in figures and compared.
基金The Key Projects of Philosophy and Social Science Research Base in Yunnan Province (JD2019ZD03)The Ministry of Culture and Tourism of People’s Republic of China (WMYC20181-083)。
文摘With the emergence of the concept of cultural routes, researchers have increasingly turned their attention to the sustainable development of tourism along cultural routes. The needs for community participation and the ongoing provision of benefits of stakeholders are characteristics of cultural routes. Therefore, the importance of cooperative relations and systematic development among stakeholders in tourism activities along cultural routes has become a subject of interest. This paper selects local government, tourism enterprises and local community residents, all of which play a key role in the Ancient Tea Horse Road cultural route in the south of Yunnan, as the main stakeholders. We use game theory to construct a model to trace interactions between local government and tourism enterprises, between tourism enterprises and community residents, and between local government and community residents. The paper then analyzes the different interests of the three parties and key factors that influence them in the game process. This provided a certain scientific basis for the win-win decisions regarding tourism development made by the three parties. Our results show that the final decision choices of the three parties depend on the initial payoff matrix of the game, and the influence of key parameters. When making decisions about tourism, the government should respect the wishes of local residents, strengthen protections of local traditions, manage the unreasonable behavior of tourism enterprises as they develop tourism, and develop appropriate penalties for violations of regulations. When tourism enterprises carry out tourism development, they should let community residents take the initiative and fully participate in tourism activities, and be sure that income from tourism is fed back to local residents, to ensure that tourism is mutually beneficial. The study shows that conflicts among the three parties originated mainly from differences in interests, but that the three parties also shared common interests. With a goal of coordinating interests, we can establish relevant mechanisms, follow the principle of interest realization, attach importance to supervision and management, strengthen community participation and decision-making, and realize win-win results for the three parties.
基金financially supported by the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen (JCYJ20200109141640095 and JCYJ20190809115413414)the National Natural Science Foundation of China (21671096 and 21905180)+2 种基金the Natural Science Foundation of Guangdong Province (2018A030310225)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power (2018B030322001)support from the Center for Computational Science and Engineering and Core Research Facilities of SUSTech。
文摘The oxygen reduction reaction (ORR) is the cornerstone reaction of the cathode in metal±air batteries;however,slow kinetics requires high-performance catalysts to promote the reaction.Polyphthalocyanine (PPc) has a typical chemical cross-linking structure and uniformly dispersed metal active sites,but its poor activity and conductivity limit its applications as an ORR catalyst.Herein,a manageable and convenient strategy is proposed to synthesize ternary ORR catalysts through the low-temperature pyrolysis of Fe PPc.The optimal catalyst,Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5,exhibits excellent ORR activity in alkaline solution with a half-wave potential of 0.90 V,which is significantly higher than that of commercial 20%Pt/C (0.84 V).Electrochemical tests and extended X-ray absorption fine structure spectroscopy reveal that the superior ORR activity of Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 could be ascribed to the balance of its ternary components(i.e.,Fe_(3)O_(4),Fe_(3)N,and Fe-N;species).A Zn±air battery incorporating Fe_(3)O_(4)/Fe_(3)N/Fe-N-C@PC-2.5 as an air cathodic catalyst delivers a high open-circuit voltage and peak power density.During galvanostatic discharge,the battery demonstrates a specific capacity of 815.7 mA h g^(-1).The facile strategy of using PPc to develop high-performance composite electrocatalysts may be expanded to develop new types of catalysts in the energy field.
文摘Hot electron emission means that electrons move over potential barriers to come out of the metal when the metal is being heated.Obviously,voltage will generate between electrons and the metal.Based on this,the model of metal hot-electron power generation is built.Free electron model of Sommerfeld is used to describe the movement of electrons in metal.According to the different width of potential barriers,two models are built.One assumes that electrons move from one metal to another mainly by moving over the potential barrier as the barrier is wide enough.The other assumes that the potential barrier is so narrow that electrons mainly move through the potential barrier by tunnel effect.The first model is analyzed and proved strictly,including the building of model,the calculation of open-circuit voltage and the drawing of volt-ampere characteristic curve.The second model is analysed simply.This paper shows that power generation by metal hot-electron is possible based on the theory and can provide reference for researching in power generation of metal hot-electron.
文摘Histone modifications have been widely elucidated to play vital roles in gene regulation and cell identity. The Roadmap Epigenomics Consortium generated a reference catalog of several key histone modifications across 〉lOOs of human cell types and tissues. Decoding these epJgenomes into functional regulatory elements is a challenging task in computational biology. To this end, we adopted a differential chromatin modification analysis framework to comprehensively determine and characterize cell type-specific regulatory elements （CSREs） and their histone modification codes in the human epigenomes of five histone modifications across 127 tissues or cell types. The CSREs show significant relevance with cell type-specific biological functions and diseases and cell identity. Clustering of CSREs with their specificity signals reveals distinct histone codes, demonstrating the diversity of functional roles of CSREs within the same cell or tissue. Last but not least, dynamics of CSREs from close cell types or tissues can give a detailed view of developmental processes such as normal tissue development and cancer occurrence.
