In the future fifth generation(5G) systems,non-orthogonal multiple access(NOMA) is a promising technology that can greatly enhance the network capacity compared to orthogonal multiple access(OMA) .In this paper,we pro...In the future fifth generation(5G) systems,non-orthogonal multiple access(NOMA) is a promising technology that can greatly enhance the network capacity compared to orthogonal multiple access(OMA) .In this paper,we propose a novel random access(RA) and resource allocation scheme for the coexistence of NOMA-based and OMAbased machine-to-machine(M2M) communications,which aims at improving the number of successful data packet transmissions and guaranteeing the quality of service(Qo S) (e.g.,the minimum data rate requirement) for M2 M communications.The algorithm of joint user equipment(UE) paring and power allocation is proposed for the coexisting RA(i.e.,the coexistence of NOMA-based RA and OMA-based RA) .The resource allocation for the coexisting RA is investigated,thus improving the number of successful data packet transmissions by more efficiently using the radio resources.Simulation results demonstrate that the proposed RA and resource allocation scheme outperforms the conventional RA in terms of the number of successful data packet transmissions,thus is a promising technology in future M2 M communications.展开更多
The method in which a source is set on the surface and electric potential is received in the borehole is called surface-borehole electric potential technique. Technique of surface-borehole electric potential was emplo...The method in which a source is set on the surface and electric potential is received in the borehole is called surface-borehole electric potential technique. Technique of surface-borehole electric potential was employed to study electric response of layered formation. The electric potential was obtained by solving Poisson equation with finite difference method. In the course of calculation, forward modeling wilth finite difference method was realized by adopting bandwidth non-zero storage technique and the incomplete Cholesky conjugate gradient method. The results show that method of surface-borehole can acquire anomalous electric potential corresponding tc geo-electric layers. In addition, application of appropriate mathematical operator can improve the resolution. Moreover, overburden low resistivity layers have severe influence on measuring results of surface-borehole electric potential. However, bottom low resistivity layers play a positive role in the measurement.展开更多
PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying pie...PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying piezoelectric mechanisms is of great importance for its application.Herein,we reveal the quantified intrinsic and extrinsic contributions to the high electrostrain of the morphotropic composition with phase coexistence by employing the advanced in situ electrical biasing high-energy synchrotron X-ray diffraction combined with the STRAP(strain,texture,and Rietveld analysis for piezoceramics from diffraction)methodology.An electric field-induced phase transformation is observed between the coexisting tetragonal and rhombohedral phases.It is found that the tetragonal phase contributes most of the domain switching strain,while the predominant lattice strain is from the rhombohedral phase.With phase fraction changes,the quantitative results demonstrate that the fieldinduced electrostrain is mainly contributed by the intrinsic lattice strain.In contrast,the high irreversible domain switching strain dominates the large remanent strain.It implies that transforming the large remanent strain into reversible strain would be a strategic direction to improve the piezoelectric response.The present results provide a further understanding of the high piezoelectricity and could help to advance the application of PbTiO_(3)-BiScO_(3).展开更多
基金supported by the National Natural Science Foundation of China(61501056)National Science and Technology Major Project of China(No.2016ZX03001012)the Research Fund of ZTE Corporation
文摘In the future fifth generation(5G) systems,non-orthogonal multiple access(NOMA) is a promising technology that can greatly enhance the network capacity compared to orthogonal multiple access(OMA) .In this paper,we propose a novel random access(RA) and resource allocation scheme for the coexistence of NOMA-based and OMAbased machine-to-machine(M2M) communications,which aims at improving the number of successful data packet transmissions and guaranteeing the quality of service(Qo S) (e.g.,the minimum data rate requirement) for M2 M communications.The algorithm of joint user equipment(UE) paring and power allocation is proposed for the coexisting RA(i.e.,the coexistence of NOMA-based RA and OMA-based RA) .The resource allocation for the coexisting RA is investigated,thus improving the number of successful data packet transmissions by more efficiently using the radio resources.Simulation results demonstrate that the proposed RA and resource allocation scheme outperforms the conventional RA in terms of the number of successful data packet transmissions,thus is a promising technology in future M2 M communications.
基金Project supported by Global Center of Excellence in Novel Carbon Resource Sciences,Kyushu University,Japan
文摘The method in which a source is set on the surface and electric potential is received in the borehole is called surface-borehole electric potential technique. Technique of surface-borehole electric potential was employed to study electric response of layered formation. The electric potential was obtained by solving Poisson equation with finite difference method. In the course of calculation, forward modeling wilth finite difference method was realized by adopting bandwidth non-zero storage technique and the incomplete Cholesky conjugate gradient method. The results show that method of surface-borehole can acquire anomalous electric potential corresponding tc geo-electric layers. In addition, application of appropriate mathematical operator can improve the resolution. Moreover, overburden low resistivity layers have severe influence on measuring results of surface-borehole electric potential. However, bottom low resistivity layers play a positive role in the measurement.
基金supported by the National Natural Science Foundation of China(21825102,22075014 and 12004032)the Fundamental Research Funds for the Central Universities,China(06500162)+2 种基金the National Postdoctoral Program for Innovative Talents(BX20200044)German Research Society(DFG)(HI 1867/1-2)supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357.
文摘PbTiO_(3)-BiScO_(3) ceramics possess high piezoelectricity and high Curie temperature simultaneously,presenting a very promising candidate for high-temperature actuators and transducers.Figuring out the underlying piezoelectric mechanisms is of great importance for its application.Herein,we reveal the quantified intrinsic and extrinsic contributions to the high electrostrain of the morphotropic composition with phase coexistence by employing the advanced in situ electrical biasing high-energy synchrotron X-ray diffraction combined with the STRAP(strain,texture,and Rietveld analysis for piezoceramics from diffraction)methodology.An electric field-induced phase transformation is observed between the coexisting tetragonal and rhombohedral phases.It is found that the tetragonal phase contributes most of the domain switching strain,while the predominant lattice strain is from the rhombohedral phase.With phase fraction changes,the quantitative results demonstrate that the fieldinduced electrostrain is mainly contributed by the intrinsic lattice strain.In contrast,the high irreversible domain switching strain dominates the large remanent strain.It implies that transforming the large remanent strain into reversible strain would be a strategic direction to improve the piezoelectric response.The present results provide a further understanding of the high piezoelectricity and could help to advance the application of PbTiO_(3)-BiScO_(3).
