To improve the reliability and accuracy of the global po- sitioning system （GPS）/micro electromechanical system （MEMS）- inertial navigation system （INS） integrated navigation system, this paper proposes two diff...To improve the reliability and accuracy of the global po- sitioning system （GPS）/micro electromechanical system （MEMS）- inertial navigation system （INS） integrated navigation system, this paper proposes two different methods. Based on wavelet threshold denoising and functional coefficient autoregressive （FAR） model- ing, a combined data processing method is presented for MEMS inertial sensor, and GPS attitude information is also introduced to improve the estimation accuracy of MEMS inertial sensor errors. Then the positioning accuracy during GPS signal short outage is enhanced. To improve the positioning accuracy when a GPS signal is blocked for long time and solve the problem of the tra- ditional adaptive neuro-fuzzy inference system （ANFIS） method with poor dynamic adaptation and large calculation amount, a self-constructive ANFIS （SCANFIS） combined with the extended Kalman filter （EKF） is proposed for MEMS-INS errors modeling and predicting. Experimental road test results validate the effi- ciency of the proposed methods.展开更多
Cubic boron nitride (c-BN) films were successfully grown on Si(100)substrates by a helicon wave plasma-assisted chemical vapor deposition technique.The lower limits of rf substrated bias voltage and plasma density for...Cubic boron nitride (c-BN) films were successfully grown on Si(100)substrates by a helicon wave plasma-assisted chemical vapor deposition technique.The lower limits of rf substrated bias voltage and plasma density for formation of a single phase c-BN film were 350V and 4.5×10￣(10) cm￣(3),respectively. The grown c-BN films demonstrated a poor adhesion to the substrates. A postannealing treatment at 800℃ C in N_2 atmosphere was found very effective in relieving the compressive stress in the films which were thereby stabilized to improve the adhesion.展开更多
The development of effcient and cheap bifunctional catalysts for oxygen reduction and oxygen evolution reactions,is vital for the design of rechargeable Zn-air batteries.Herein,a facile strategy to fabricate Co/Co_(9)...The development of effcient and cheap bifunctional catalysts for oxygen reduction and oxygen evolution reactions,is vital for the design of rechargeable Zn-air batteries.Herein,a facile strategy to fabricate Co/Co_(9)S_(8)nanoparticles-encapsulated in carbon nanotubes,on an N-doped porous graphene sheet(Co/Co_(9)S_(8)@CNTs)via pyrolysis of a mixture of Co(NO_(3))_(2),melamine and L-cysteine is reported,the compo sition can be facile controlled using the molar ratio of melamine and L-cysteine.By controlling the molar ratio of melamine and L-cysteine and the pyrolysis temperature,Co/Co_(9)S_(8)@CNTs obtained at 900℃(Co/Co_(9)S_(8)@CNTs-900)perform with high activities in oxygen reduction and oxygen evolution reactions,which promotes their application for rechargeable Zn-air batteries.Furthermore,the rechargeable Zn-air battery assembled with Co/Co_(9)S_(8)@CNTs-900 shows a high peak power density of 184.7 mW cm^(−2)and good long-term durability,holding great potential in practical applications.展开更多
We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-glu...We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.展开更多
基金supported by the National Natural Science Foundation of China (60902055)
文摘To improve the reliability and accuracy of the global po- sitioning system （GPS）/micro electromechanical system （MEMS）- inertial navigation system （INS） integrated navigation system, this paper proposes two different methods. Based on wavelet threshold denoising and functional coefficient autoregressive （FAR） model- ing, a combined data processing method is presented for MEMS inertial sensor, and GPS attitude information is also introduced to improve the estimation accuracy of MEMS inertial sensor errors. Then the positioning accuracy during GPS signal short outage is enhanced. To improve the positioning accuracy when a GPS signal is blocked for long time and solve the problem of the tra- ditional adaptive neuro-fuzzy inference system （ANFIS） method with poor dynamic adaptation and large calculation amount, a self-constructive ANFIS （SCANFIS） combined with the extended Kalman filter （EKF） is proposed for MEMS-INS errors modeling and predicting. Experimental road test results validate the effi- ciency of the proposed methods.
文摘Cubic boron nitride (c-BN) films were successfully grown on Si(100)substrates by a helicon wave plasma-assisted chemical vapor deposition technique.The lower limits of rf substrated bias voltage and plasma density for formation of a single phase c-BN film were 350V and 4.5×10￣(10) cm￣(3),respectively. The grown c-BN films demonstrated a poor adhesion to the substrates. A postannealing treatment at 800℃ C in N_2 atmosphere was found very effective in relieving the compressive stress in the films which were thereby stabilized to improve the adhesion.
基金supported by the National Natural Science Foundation of China(51673117,21805193,51574166,51602199)the Science and Technology Innovation Commission of Shenzhen(JCYJ20170817094628397,JCYJ20180305125319991,JCYJ20170818093832350,JCYJ2017-0818112409808,JSGG20170824112840518,JCYJ201805071847-11069,JCYJ20170818100112531,JCYJ20170818101016362,JCYJ20170817094628397)the Key R&D Program of Guangdong Province(2019B010929002,2019B010941001).
文摘The development of effcient and cheap bifunctional catalysts for oxygen reduction and oxygen evolution reactions,is vital for the design of rechargeable Zn-air batteries.Herein,a facile strategy to fabricate Co/Co_(9)S_(8)nanoparticles-encapsulated in carbon nanotubes,on an N-doped porous graphene sheet(Co/Co_(9)S_(8)@CNTs)via pyrolysis of a mixture of Co(NO_(3))_(2),melamine and L-cysteine is reported,the compo sition can be facile controlled using the molar ratio of melamine and L-cysteine.By controlling the molar ratio of melamine and L-cysteine and the pyrolysis temperature,Co/Co_(9)S_(8)@CNTs obtained at 900℃(Co/Co_(9)S_(8)@CNTs-900)perform with high activities in oxygen reduction and oxygen evolution reactions,which promotes their application for rechargeable Zn-air batteries.Furthermore,the rechargeable Zn-air battery assembled with Co/Co_(9)S_(8)@CNTs-900 shows a high peak power density of 184.7 mW cm^(−2)and good long-term durability,holding great potential in practical applications.
基金support by the NSFC(11875113)the Shanghai Municipality(KBH1512299)+5 种基金Fudan University(JJH1512105)supported by the Swedish Research Council,contract numbers 621-2013-428 and 2016-05996CONICYT grant MEC80170112(Chile)the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(668679)supported in part by the Ministry of Education,Youth and Sports of the Czech Republic,project LT17018the framework of COST Action CA15213 “Theory of hot matter and relativistic heavy-ion collisions”(THOR)
文摘We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.
