Recently,the memory elements-based circuits have been addressed frequently in the nonlinear circuit theory due to their unique behaviors.Thus,the modeling and characterizing of the mem-elements become essential.In thi...Recently,the memory elements-based circuits have been addressed frequently in the nonlinear circuit theory due to their unique behaviors.Thus,the modeling and characterizing of the mem-elements become essential.In this paper,the analysis of the multiple fractional-order voltage-controlled memcapacitors model in parallel connection is studied.Firstly,two fractional-order memcapacitors are connected in parallel,the equivalent model is derived,and the characteristic of the equivalent memcapacitor is analyzed in positive or negative connection.Then a new understanding manner according to different rate factor K and fractional orderαis derived to explain the equivalent modeling structure conveniently.Additionally,the negative order appears,which is a consequence of the combination of memcapacitors in different directions.Meanwhile,the equivalent parallel memcapacitance has been drawn to determine that multiple fractional-order memcapacitors could be calculated as one composite memcapacitor.Thus,an arbitrary fractional-order equivalent memcapacitor could be constructed by multiple fractional-order memcapacitors.展开更多
Abstract Abstract:We have demonstrated using vectorized parallel Lennard-Jones fluid program that vectorizing general-purpose parallel molecular package for simulating biomolecules which currently runs on the Connect...Abstract Abstract:We have demonstrated using vectorized parallel Lennard-Jones fluid program that vectorizing general-purpose parallel molecular package for simulating biomolecules which currently runs on the Connection Machine CM-5 using CMMD message passing would offer a significant improvement over 4 non-vectorized version. Our results indicate that the Lennard-Jones fluid program written in C*/CMNID is five times faster than the same program written in C/CMMD.展开更多
Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the...Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the cymbal hydrophone was improved. The single ceramic piezoelectric element was replaced with a double one, the radius of the ceramic piezoelectric element was reduced, and a parallel circuit was added. A static analysis of this new structure was developed, and then simulations were made of both the traditional and new hydrophone structure using finite element software. Tests were then conducted in a tank. The results showed that the improved hydrophone has reception in a wider frequency band, reception performance is stable within this frequency band, and sensitivity is still high.展开更多
New semiconductor materials offer several advantages for modern power systems,including low switching and conduction losses,excellent thermal conduction of a die,and high operation temperature.Avionics is one of the m...New semiconductor materials offer several advantages for modern power systems,including low switching and conduction losses,excellent thermal conduction of a die,and high operation temperature.Avionics is one of the main beneficiaries of the progress in power devices,as it enables more compact and lighter converters for future More Electrical Aircraft.However,these advancements also come with new challenges that must be addressed to avoid potentially dangerous situations and fully utilize the capabilities of fast SiC MOSFETs.One such challenge is the high drain voltage rate during the switching process,which leads to a significant injection of current into the gate circuit(crosstalk effect).This increased current injection increases the risk of shoot-through conduction and thermal runaway.Although preventive measures are well-known,they offer limited protection in the case of parallel MOSFET connections.Therefore,this paper considers crosstalk features for parallel MOSFET connections,such as parasitic inductance of gate driver trace and gate voltage distribution.A special model is proposed to predict the magnitude of induced gate voltage under different conditions considering the nonlinear behavior of the MOSFET reverse capacitance.A new clamp circuit with an individual low-inductance path for each parallel switch is also proposed to suppress the consequences of crosstalk.The modified circuit operates independently from the main gate driver circuit;therefore,it does not change the switching time and electromagnetic interference pattern of the inverter.The efficiency of the new gate driver is confirmed through simulation and experimental results.展开更多
In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connectio...In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connection and parallel connection） of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up.展开更多
This paper focuses on analyzing the composite dynamic behaviors of two meminductors in serial and parallel connec- tions with different polarities. Based on the constitutive relations, two time-integral-of-flux （TIF...This paper focuses on analyzing the composite dynamic behaviors of two meminductors in serial and parallel connec- tions with different polarities. Based on the constitutive relations, two time-integral-of-flux （TIF） controlled meminductors are adopted to theoretically demonstrate the variation of memductance in terms of TIF, charge, flux, and current. By uti- lizing a floating memristor-less meminductor emulator, the theoretical analysis reported in this paper is confirmed via a PSPICE simulation study and hardware experiment. Good agreement among theoretical analysis, simulation, and hardware validation confirms that dual meminductor circuits in composite connections behave as a new meminductor with higher complexity.展开更多
In this paper, by referring to the concept of coupled memristors （MRs） and considering the flux coupling connection, the constitutive relations for describing the coupled memcapacitors （MCs） are theoretically dedu...In this paper, by referring to the concept of coupled memristors （MRs） and considering the flux coupling connection, the constitutive relations for describing the coupled memcapacitors （MCs） are theoretically deduced. The dynamic behaviors of dual coupled MCs in serial and parallel connections are analyzed in terms of identical or opposite polarities for the first time. Based on the derived constitutive relations of the two coupled MCs, the modified relaxation oscillators （ROs） are obtained with the purpose of achieving controllable oscillation frequency and duty cycle. In consideration of different parameter configurations, the experimental investigation is carried out by using practical off-the-shelf circuit components to verify the correction of the theoretical calculation with numerical simulation of the coupled MCs and its application in ROs.展开更多
Hydrogen energy plays an important role in achieving carbon neutralization,and plasma induced hydrogen is an effective production method.One challenge is how to guarantee high efficiency operation with wide power outp...Hydrogen energy plays an important role in achieving carbon neutralization,and plasma induced hydrogen is an effective production method.One challenge is how to guarantee high efficiency operation with wide power output range of the RF inverter system used to generate the plasma.In this paper,a multi-module parallel topology of a high-frequency inverter is analyzed,in which the power combining network can maintain the soft switching characteristics of the inverter modules.A control method of"ON/OFF+phase shift"is adopted to broaden the output power range of the inverter.The equivalent impedances of different modules are analyzed in detail.A four-module 13.56 MHz high-frequency inverter prototype is built and tested.The results show that the inverter can operate at high efficiency and wide output power range with efficiency improved by at least 5%compared with the traditional parameter design method without considering the effect of paralleled modules.展开更多
基金the National Natural Science Foundation of China(Grant No.52077160).
文摘Recently,the memory elements-based circuits have been addressed frequently in the nonlinear circuit theory due to their unique behaviors.Thus,the modeling and characterizing of the mem-elements become essential.In this paper,the analysis of the multiple fractional-order voltage-controlled memcapacitors model in parallel connection is studied.Firstly,two fractional-order memcapacitors are connected in parallel,the equivalent model is derived,and the characteristic of the equivalent memcapacitor is analyzed in positive or negative connection.Then a new understanding manner according to different rate factor K and fractional orderαis derived to explain the equivalent modeling structure conveniently.Additionally,the negative order appears,which is a consequence of the combination of memcapacitors in different directions.Meanwhile,the equivalent parallel memcapacitance has been drawn to determine that multiple fractional-order memcapacitors could be calculated as one composite memcapacitor.Thus,an arbitrary fractional-order equivalent memcapacitor could be constructed by multiple fractional-order memcapacitors.
文摘Abstract Abstract:We have demonstrated using vectorized parallel Lennard-Jones fluid program that vectorizing general-purpose parallel molecular package for simulating biomolecules which currently runs on the Connection Machine CM-5 using CMMD message passing would offer a significant improvement over 4 non-vectorized version. Our results indicate that the Lennard-Jones fluid program written in C*/CMNID is five times faster than the same program written in C/CMMD.
文摘Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the cymbal hydrophone was improved. The single ceramic piezoelectric element was replaced with a double one, the radius of the ceramic piezoelectric element was reduced, and a parallel circuit was added. A static analysis of this new structure was developed, and then simulations were made of both the traditional and new hydrophone structure using finite element software. Tests were then conducted in a tank. The results showed that the improved hydrophone has reception in a wider frequency band, reception performance is stable within this frequency band, and sensitivity is still high.
基金supported by Natural Science Foundation of China with grant No.52250610219the Ningbo National Science Foundation grant 2023J025。
文摘New semiconductor materials offer several advantages for modern power systems,including low switching and conduction losses,excellent thermal conduction of a die,and high operation temperature.Avionics is one of the main beneficiaries of the progress in power devices,as it enables more compact and lighter converters for future More Electrical Aircraft.However,these advancements also come with new challenges that must be addressed to avoid potentially dangerous situations and fully utilize the capabilities of fast SiC MOSFETs.One such challenge is the high drain voltage rate during the switching process,which leads to a significant injection of current into the gate circuit(crosstalk effect).This increased current injection increases the risk of shoot-through conduction and thermal runaway.Although preventive measures are well-known,they offer limited protection in the case of parallel MOSFET connections.Therefore,this paper considers crosstalk features for parallel MOSFET connections,such as parasitic inductance of gate driver trace and gate voltage distribution.A special model is proposed to predict the magnitude of induced gate voltage under different conditions considering the nonlinear behavior of the MOSFET reverse capacitance.A new clamp circuit with an individual low-inductance path for each parallel switch is also proposed to suppress the consequences of crosstalk.The modified circuit operates independently from the main gate driver circuit;therefore,it does not change the switching time and electromagnetic interference pattern of the inverter.The efficiency of the new gate driver is confirmed through simulation and experimental results.
基金supported by the National Science and Technology Plan(Major Project of the Eleventh Five-Year Plan,Grant No.2006BAB04A13)
文摘In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connection and parallel connection） of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up.
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2013QNB28.)
文摘This paper focuses on analyzing the composite dynamic behaviors of two meminductors in serial and parallel connec- tions with different polarities. Based on the constitutive relations, two time-integral-of-flux （TIF） controlled meminductors are adopted to theoretically demonstrate the variation of memductance in terms of TIF, charge, flux, and current. By uti- lizing a floating memristor-less meminductor emulator, the theoretical analysis reported in this paper is confirmed via a PSPICE simulation study and hardware experiment. Good agreement among theoretical analysis, simulation, and hardware validation confirms that dual meminductor circuits in composite connections behave as a new meminductor with higher complexity.
基金Project supported by the Fundamental Research Funds for China Central Universities(Grant No.2015XKMS028)
文摘In this paper, by referring to the concept of coupled memristors （MRs） and considering the flux coupling connection, the constitutive relations for describing the coupled memcapacitors （MCs） are theoretically deduced. The dynamic behaviors of dual coupled MCs in serial and parallel connections are analyzed in terms of identical or opposite polarities for the first time. Based on the derived constitutive relations of the two coupled MCs, the modified relaxation oscillators （ROs） are obtained with the purpose of achieving controllable oscillation frequency and duty cycle. In consideration of different parameter configurations, the experimental investigation is carried out by using practical off-the-shelf circuit components to verify the correction of the theoretical calculation with numerical simulation of the coupled MCs and its application in ROs.
基金funded by National Natural Science Foundation of China under grant 52007041.
文摘Hydrogen energy plays an important role in achieving carbon neutralization,and plasma induced hydrogen is an effective production method.One challenge is how to guarantee high efficiency operation with wide power output range of the RF inverter system used to generate the plasma.In this paper,a multi-module parallel topology of a high-frequency inverter is analyzed,in which the power combining network can maintain the soft switching characteristics of the inverter modules.A control method of"ON/OFF+phase shift"is adopted to broaden the output power range of the inverter.The equivalent impedances of different modules are analyzed in detail.A four-module 13.56 MHz high-frequency inverter prototype is built and tested.The results show that the inverter can operate at high efficiency and wide output power range with efficiency improved by at least 5%compared with the traditional parameter design method without considering the effect of paralleled modules.
