The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps...The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic material.Based on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are investigated.For verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is constructed.Compared with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA results.The experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.展开更多
The maintenance of cellular phosphate(Pi)homeostasis is of great importance in living organisms.The SPX domain-containing protein 1(SPX1)proteins from both Arabidopsis and rice have been proposed to act as sensors of ...The maintenance of cellular phosphate(Pi)homeostasis is of great importance in living organisms.The SPX domain-containing protein 1(SPX1)proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status.The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants,however,remains to be identified,as Pi itself does not bind to the SPX domain.Here,we report the identification of the inositol pyrophosphate lnsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis.Polyacrylamide gel electrophoresis profiling of InsPs revealed that lnsP8 level positively correlates with cellular Pi concentration.We demonstrated that the homologs of diphosphoinositol pentaki-sphosphate kinase(PPIP5K),VIH1 and VIH2,function redundantly to synthesize lnsP8,and that the vih1 vih2 double mutant overaccumulates Pi.SPX1 directly interacts with PHR1,the central regulator of Pi starvation responses,to inhibit its function under Pi-replete conditions.However,this interaction is compromised in the vih1 vih2 double mutant,resulting in the constitutive induction of Pi starvation-induced genes,indicating that plant cells cannot sense cellular Pi status without lnsP8.Furthermore,we showed that lnsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1.Collectively,our study suggests that lnsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.展开更多
基金co-supported by the National Natural Science Foundation of China(No.51975275)Primary Research&Development Plan of Jiangsu Province,China(No.BE2021034)Postgraduate Research&Practice Innovation Program of NUAA,China(No.xcxjh20210502).
文摘The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic material.Based on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are investigated.For verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is constructed.Compared with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA results.The experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.
文摘The maintenance of cellular phosphate(Pi)homeostasis is of great importance in living organisms.The SPX domain-containing protein 1(SPX1)proteins from both Arabidopsis and rice have been proposed to act as sensors of Pi status.The molecular signal indicating the cellular Pi status and regulating Pi homeostasis in plants,however,remains to be identified,as Pi itself does not bind to the SPX domain.Here,we report the identification of the inositol pyrophosphate lnsP8 as a signaling molecule that regulates Pi homeostasis in Arabidopsis.Polyacrylamide gel electrophoresis profiling of InsPs revealed that lnsP8 level positively correlates with cellular Pi concentration.We demonstrated that the homologs of diphosphoinositol pentaki-sphosphate kinase(PPIP5K),VIH1 and VIH2,function redundantly to synthesize lnsP8,and that the vih1 vih2 double mutant overaccumulates Pi.SPX1 directly interacts with PHR1,the central regulator of Pi starvation responses,to inhibit its function under Pi-replete conditions.However,this interaction is compromised in the vih1 vih2 double mutant,resulting in the constitutive induction of Pi starvation-induced genes,indicating that plant cells cannot sense cellular Pi status without lnsP8.Furthermore,we showed that lnsP8 could directly bind to the SPX domain of SPX1 and is essential for the interaction between SPX1 and PHR1.Collectively,our study suggests that lnsP8 is the intracellular Pi signaling molecule serving as the ligand of SPX1 for controlling Pi homeostasis in plants.
