For a commtative ring R and an injective cogenerator E in the category of R-modules, we characterize QF rings, IF rings and semihereditary rings by using the properties of the dual modules with respect to E.
A module pair (C, T) over an Artin algebra A is called a tilting pair if both C and T are selforthogonal modules and the conditions T e ada C and C ∈ add T hold. The duality on a tilting pair is investigated to dis...A module pair (C, T) over an Artin algebra A is called a tilting pair if both C and T are selforthogonal modules and the conditions T e ada C and C ∈ add T hold. The duality on a tilting pair is investigated to discuss the condition under which the dual of a tilting pair is also a tilting pair. A necessary and sufficient condition of (D(7), D(C) ) being an n-tilting pair over an Artin algebra for an n-tilting pair ( C, 7) is given. And, a necessary and sufficient condition of ( T^*, C^* ) being an ntilting pair over a selfinjective Artin algebra for an n-tilting pair (C, 7) is also given.展开更多
The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits s...The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current(SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarizationmodulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state(RS), which is formed by the double ferroelectric layer Ba TiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory(RRAM) devices based on ferroelectric materials.展开更多
In this paper,a novel dual flux modulation(DFM)machine with consequent-pole spoke-array permanent magnets(PMs)in both stator and rotor is proposed to achieve a larger torque density than regular flux modulation machin...In this paper,a novel dual flux modulation(DFM)machine with consequent-pole spoke-array permanent magnets(PMs)in both stator and rotor is proposed to achieve a larger torque density than regular flux modulation machines.The stator has two portions of PMs,one is set next to the stator slot with circumferential magnetization,and the other is inserted between the stator yoke and flux bridge with radial magnetization.The rotor has consequent-pole spoke-array PMs and alternative flux bridges.The proposed DFMPM machine can be regarded as the combination of the flux switching PM(FSPM)machine and vernier PM(VPM)machine.First,the structure and operational principle are introduced.Then,the proposed 12-stator-slot/10-rotor-tooth dual flux modulation permanent magnet(DFMPM)machine is compared with the FSPM machine and VPM machine in terms of flux lines distribution,back-electromotive force(EMF),cogging torque and average torque.Finally,the four proposed DFMPM machines are optimized for maximum average torque and minimum ripple torque considering the effects of split ratio,slot opening ratio,PM depth,PM angle and iron angle.展开更多
In this paper, we characterize the structure of group graded primitive rings having minimal graded one-sided ideals in terms of graded dual modules. We also show that two structure representations of this class of gra...In this paper, we characterize the structure of group graded primitive rings having minimal graded one-sided ideals in terms of graded dual modules. We also show that two structure representations of this class of graded primitive rings are both in a sense uniquely determined by the graded primitive rings considered.展开更多
The concepts of strongly lifting modules and strongly dual Rickart modules are introduced and their properties are studied and relations between them are given in this paper. It is shown that a strongly lifting module...The concepts of strongly lifting modules and strongly dual Rickart modules are introduced and their properties are studied and relations between them are given in this paper. It is shown that a strongly lifting module has the strongly summand sum property and the generalized Hopfian property, and a ring R is a strongly regular ring if and only if RR is a strongly dual Rickart module, if and only if aR is a fully invariant direct summand of RR for every a∈R.展开更多
A new scheme is offered for minimizing carrier Rayleigh backscattering(CRB) in single feeder fiber based wavelength division multiplexed passive optical network(WDM-PON). The proposed scheme is based on single side ba...A new scheme is offered for minimizing carrier Rayleigh backscattering(CRB) in single feeder fiber based wavelength division multiplexed passive optical network(WDM-PON). The proposed scheme is based on single side band carrier suppressed(SSBCS) signal, both at network and receiver sides, used for the first time at optical line terminal(OLT) and optical network unit(ONU) sides. We use dual-drive Mach-zehnder modulator(DD-MZM) for generating SSB-CS signals, which decreases the expense per bit in full transmission. SSB-CS mitigates CRB, both at OLT and ONU sides, because of having no chance of reflections from the carrier. Since no extra dedicated RF or laser source is used at ONU side, we thus achieve cost effective colorless WDM-PON system. Suppressed signals from four channels, each of 10 Gbps, are multiplexed before injecting into the fiber span of 25 km at OLT. At ONU side, half of the downlink power is used for re-modulating the data signal. The simulation results show an errorfree transmission. Moreover, the detailed power budget calculations show that the proposed scheme can be sought out for splitting ratio up to 128. Hence it offers enough system's margin for unseen losses.展开更多
Single voltage vectors applied in the conventional model predictive torque control(MPTC)for multiphase motors do not only suffer from serious torque and stator flux ripples but also cause the large harmonic current.To...Single voltage vectors applied in the conventional model predictive torque control(MPTC)for multiphase motors do not only suffer from serious torque and stator flux ripples but also cause the large harmonic current.To address the aforementioned challenges,an MPTC using a modified dual virtual vector modulation method is proposed to improve the operational performance of a dual three-phase permanent magnet synchronous motor.Virtual voltage vectors are synthesized as the candidate control set to restrain the harmonic current.A transformation method is introduced to consider both the stator flux and torque in the duty cycle modulation.The torque and stator flux ripples are simultaneously reduced by addressing the limitations of nonuniform units.Furthermore,the null voltage vector is then inserted to expand the modulation range and improve the steady-state performance.Moreover,the sawtooth carrier is adopted to address the challenge of the asymmetric switch sequence caused by the modified modulation.Finally,the experimental results are presented to verify the effectiveness and superiority of the proposed MPTC method.展开更多
Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most prevalent chronic liver disease globally,with only one Food and Drug Administration(FDA)-approved drug for its treatment.Given MASLD's com...Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most prevalent chronic liver disease globally,with only one Food and Drug Administration(FDA)-approved drug for its treatment.Given MASLD's complex pathophysiology,ther-apies that simultaneously target multiple pathways are highly desirable.One promising approach is dual-modulation of the famesoid X receptor(FXR),which regulates lipid and bile acid metabolism.However,FXR agonists alone are insufficient due to their limited anti-inflammatory effects.This study aimed to dto identify natural products capable of both FXR activation and inflammation inhibition to provide a comprehensive therapeutic approach for MASLD.Potential FXR ligands from the Natural Product Library were predicted via virtual screening using the Protein Preparation Wizard module in Schrodinger(2018)for molecular docking.Direct binding and regulation of candidate compounds on FXR were analyzed using surface plasmon resonance(SPR)binding assay,reporter gene ana-lysis,and reverse transcription-polymerase chain reaction(RT-PCR).The anti-inflammatory properties of these compounds were eval-uated in AML12 cells treated with tumor necrosis factor-alpha(TNF-α).Dual-function compounds with FXR agonism and inflamma-tion inhibition were further identified in cells transfected with Fxr siRNA and treated with TNF-α.The effects of these dual-function compounds on lipid accumulation and inflammation were evaluated in cells treated with palmitic acid.Results revealed that 17 natural products were predicted via computational molecular docking as potential FXR agonists,with 15 exhibiting a strong affinity for FXR recombinant protein.Nine isoflavone compounds significantly enhanced FXR reporter luciferase activity and the mRNA expressions of Shp and Ostb.Structure-activity relationship analysis indicated that introducing isopropyl or methoxy groups at the C7 position or a methoxy group at the C6 position could enhance the agonistic efficacy of isoflavones.Three compounds(2,6,and 8)were identified as dual-function natural products functioning as FXR agonists and inflammatory inhibitors,while one compound(12)acted as an FXR agonist to inhibit inflammation.These natural products protected hepatocytes against palmitic acid-induced lipid accumulation and in-flammation.In conclusion,compounds 2,6,and 8(genistein,biochanin A,and 7-methoxyisoflavone,respectively)were identified as dual-function bioactive products that transactivate FXR and inhibit inflammation,serving as potential candidates or lead compounds for MASLD therapy.展开更多
基金Supported by National Natural Science Foundation of China (10001017)Scientific Research Foundation for Returned Overseas Chi
文摘For a commtative ring R and an injective cogenerator E in the category of R-modules, we characterize QF rings, IF rings and semihereditary rings by using the properties of the dual modules with respect to E.
基金The National Natural Science Foundation of China (No.10971024)the Specialized Research Fund for the Doctoral Program of Higher Education ( No. 200802860024)+1 种基金the Natural Science Foundation of Jiangsu Province ( No. BK2010393 )Scientific Research Foundation of Guangxi University ( No. XJZ100246)
文摘A module pair (C, T) over an Artin algebra A is called a tilting pair if both C and T are selforthogonal modules and the conditions T e ada C and C ∈ add T hold. The duality on a tilting pair is investigated to discuss the condition under which the dual of a tilting pair is also a tilting pair. A necessary and sufficient condition of (D(7), D(C) ) being an n-tilting pair over an Artin algebra for an n-tilting pair ( C, 7) is given. And, a necessary and sufficient condition of ( T^*, C^* ) being an ntilting pair over a selfinjective Artin algebra for an n-tilting pair (C, 7) is also given.
基金Project supported by the Scientific Research Program of Hunan Provincial Education Department,China(Grant No.18C0232)the International Cooperative Extension Program of Changsha University of Science and Technology,China(Grant No.2019IC35)
文摘The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide(FTO) substrate by the sol–gel method. The results indicate that the Pt/Ba TiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current(SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarizationmodulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state(RS), which is formed by the double ferroelectric layer Ba TiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory(RRAM) devices based on ferroelectric materials.
基金This work was supported by National Natural Science Foundation of China(NSFC)under Project Number 51520105010 and 51607079。
文摘In this paper,a novel dual flux modulation(DFM)machine with consequent-pole spoke-array permanent magnets(PMs)in both stator and rotor is proposed to achieve a larger torque density than regular flux modulation machines.The stator has two portions of PMs,one is set next to the stator slot with circumferential magnetization,and the other is inserted between the stator yoke and flux bridge with radial magnetization.The rotor has consequent-pole spoke-array PMs and alternative flux bridges.The proposed DFMPM machine can be regarded as the combination of the flux switching PM(FSPM)machine and vernier PM(VPM)machine.First,the structure and operational principle are introduced.Then,the proposed 12-stator-slot/10-rotor-tooth dual flux modulation permanent magnet(DFMPM)machine is compared with the FSPM machine and VPM machine in terms of flux lines distribution,back-electromotive force(EMF),cogging torque and average torque.Finally,the four proposed DFMPM machines are optimized for maximum average torque and minimum ripple torque considering the effects of split ratio,slot opening ratio,PM depth,PM angle and iron angle.
基金Foundation item:The NSF(993521738)of Liaoning Education Department
文摘In this paper, we characterize the structure of group graded primitive rings having minimal graded one-sided ideals in terms of graded dual modules. We also show that two structure representations of this class of graded primitive rings are both in a sense uniquely determined by the graded primitive rings considered.
基金Acknowledgements This work was supported by the Natural Science Foundation of Gansu Province (No. 1310RJZA029) and the Fundamental Research F~nds for the Universities in Gansu Province.
文摘The concepts of strongly lifting modules and strongly dual Rickart modules are introduced and their properties are studied and relations between them are given in this paper. It is shown that a strongly lifting module has the strongly summand sum property and the generalized Hopfian property, and a ring R is a strongly regular ring if and only if RR is a strongly dual Rickart module, if and only if aR is a fully invariant direct summand of RR for every a∈R.
基金financial supports from National High Technology 863 Program of China(No. 2013AA013403,2013AA013301/02,20 15AA015501/02)National NSFC(No. 61425022/61307086/ 61475024/6127515 8/61201151/61275074/61205066)+4 种基金NITC (No.2012DFG12110)Beijing Nova Program(No.Z141101001814048)Beijing Excellent Ph.D.Thesis Guidance Foundation (No.20121001302) are gratefully acknowledgedsupported by the Universities Ph.D.Special Research Funds (No.20120005110003/ 20120005120007)Fund of State Key Laboratory of IPOC (BUPT)
文摘A new scheme is offered for minimizing carrier Rayleigh backscattering(CRB) in single feeder fiber based wavelength division multiplexed passive optical network(WDM-PON). The proposed scheme is based on single side band carrier suppressed(SSBCS) signal, both at network and receiver sides, used for the first time at optical line terminal(OLT) and optical network unit(ONU) sides. We use dual-drive Mach-zehnder modulator(DD-MZM) for generating SSB-CS signals, which decreases the expense per bit in full transmission. SSB-CS mitigates CRB, both at OLT and ONU sides, because of having no chance of reflections from the carrier. Since no extra dedicated RF or laser source is used at ONU side, we thus achieve cost effective colorless WDM-PON system. Suppressed signals from four channels, each of 10 Gbps, are multiplexed before injecting into the fiber span of 25 km at OLT. At ONU side, half of the downlink power is used for re-modulating the data signal. The simulation results show an errorfree transmission. Moreover, the detailed power budget calculations show that the proposed scheme can be sought out for splitting ratio up to 128. Hence it offers enough system's margin for unseen losses.
基金Supported by the National Natural Science Foundation of China under Grant 51977099the Natural Science Foundation of Jiangsu Province under Grant BK20191225the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Single voltage vectors applied in the conventional model predictive torque control(MPTC)for multiphase motors do not only suffer from serious torque and stator flux ripples but also cause the large harmonic current.To address the aforementioned challenges,an MPTC using a modified dual virtual vector modulation method is proposed to improve the operational performance of a dual three-phase permanent magnet synchronous motor.Virtual voltage vectors are synthesized as the candidate control set to restrain the harmonic current.A transformation method is introduced to consider both the stator flux and torque in the duty cycle modulation.The torque and stator flux ripples are simultaneously reduced by addressing the limitations of nonuniform units.Furthermore,the null voltage vector is then inserted to expand the modulation range and improve the steady-state performance.Moreover,the sawtooth carrier is adopted to address the challenge of the asymmetric switch sequence caused by the modified modulation.Finally,the experimental results are presented to verify the effectiveness and superiority of the proposed MPTC method.
基金supported by the National Natural Science Foundation of China(Nos.81930109,82321005,82073926,82373946 and 82073928)the Major State Basic Research DevelopmentProgramofChina(Nos.2021YFA1301300and 2022YFA1303800)+3 种基金Overseas Expertise Introduction Project for Discipline Innovation(No.G20582017001)the Project of State Key Laboratory of Natural Medicines,China Pharmaceutical University(Nos.SKLNMZZ202202 and SKLNMZZ202402)the Fundamental Research Funds for the Central Universities(No.2632023TD10)the Project Program of Basic Science Research Center Base(Pharmaceutical Science)of Yantai University(No.Y202204).
文摘Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most prevalent chronic liver disease globally,with only one Food and Drug Administration(FDA)-approved drug for its treatment.Given MASLD's complex pathophysiology,ther-apies that simultaneously target multiple pathways are highly desirable.One promising approach is dual-modulation of the famesoid X receptor(FXR),which regulates lipid and bile acid metabolism.However,FXR agonists alone are insufficient due to their limited anti-inflammatory effects.This study aimed to dto identify natural products capable of both FXR activation and inflammation inhibition to provide a comprehensive therapeutic approach for MASLD.Potential FXR ligands from the Natural Product Library were predicted via virtual screening using the Protein Preparation Wizard module in Schrodinger(2018)for molecular docking.Direct binding and regulation of candidate compounds on FXR were analyzed using surface plasmon resonance(SPR)binding assay,reporter gene ana-lysis,and reverse transcription-polymerase chain reaction(RT-PCR).The anti-inflammatory properties of these compounds were eval-uated in AML12 cells treated with tumor necrosis factor-alpha(TNF-α).Dual-function compounds with FXR agonism and inflamma-tion inhibition were further identified in cells transfected with Fxr siRNA and treated with TNF-α.The effects of these dual-function compounds on lipid accumulation and inflammation were evaluated in cells treated with palmitic acid.Results revealed that 17 natural products were predicted via computational molecular docking as potential FXR agonists,with 15 exhibiting a strong affinity for FXR recombinant protein.Nine isoflavone compounds significantly enhanced FXR reporter luciferase activity and the mRNA expressions of Shp and Ostb.Structure-activity relationship analysis indicated that introducing isopropyl or methoxy groups at the C7 position or a methoxy group at the C6 position could enhance the agonistic efficacy of isoflavones.Three compounds(2,6,and 8)were identified as dual-function natural products functioning as FXR agonists and inflammatory inhibitors,while one compound(12)acted as an FXR agonist to inhibit inflammation.These natural products protected hepatocytes against palmitic acid-induced lipid accumulation and in-flammation.In conclusion,compounds 2,6,and 8(genistein,biochanin A,and 7-methoxyisoflavone,respectively)were identified as dual-function bioactive products that transactivate FXR and inhibit inflammation,serving as potential candidates or lead compounds for MASLD therapy.