We show that the torsion module Tor_(j)^(R)(R/a,H_(a)^(i)(X))is in a Serre subcategory for the bounded below R-complex X.In addition,we prove the isomorphism Tor_(s-t)^(R)(R/a,X)≅Tor_(s)^(R)(R/a,H_(a)^(t)(X))in some c...We show that the torsion module Tor_(j)^(R)(R/a,H_(a)^(i)(X))is in a Serre subcategory for the bounded below R-complex X.In addition,we prove the isomorphism Tor_(s-t)^(R)(R/a,X)≅Tor_(s)^(R)(R/a,H_(a)^(t)(X))in some case.As an application,the Betti number of a complex X in a prime ideal p can be computed by the Betti number of the local cohomology modules of X in p.展开更多
运用Mawhin重合度理论,讨论一类半直线上三阶多点边值问题(q(t)x″(t))′=f(t,x(t),x′(t),x″(t)),a.e.t∈[0,+∞);■(η■在dim Ker L=2共振情形下的可解性,获得了该边值问题至少存在一个解的充分条件.这里f:[0,1]×R^(3)→R满足L...运用Mawhin重合度理论,讨论一类半直线上三阶多点边值问题(q(t)x″(t))′=f(t,x(t),x′(t),x″(t)),a.e.t∈[0,+∞);■(η■在dim Ker L=2共振情形下的可解性,获得了该边值问题至少存在一个解的充分条件.这里f:[0,1]×R^(3)→R满足L^(1)[0,+∞)-Carathéodory条件,αi,βj∈R(1≤i≤m,1≤j≤n),0<ξ_(1)<ξ_(2)<…<ξ_(m)<+∞,0<η_(1)<η_(2)<…<η_(n)<+∞(m,n∈Z+),q(t)>0,q(t)∈C[0,+∞)∩C^(2)(0,+∞),1/q(t)∈L^(1)[0,+∞).展开更多
为了提高星地系统的资源利用率和用户公平性,提出一种无线携能(simultaneous wireless information and power transfer,SWIPT)非正交多址接入(non-orthogonal multiple access,NOMA)技术辅助星地系统的传输方案.首先,在非理想信道状态...为了提高星地系统的资源利用率和用户公平性,提出一种无线携能(simultaneous wireless information and power transfer,SWIPT)非正交多址接入(non-orthogonal multiple access,NOMA)技术辅助星地系统的传输方案.首先,在非理想信道状态信息(channel state information,CSI)条件下研究了系统的中断性能,并推导了中断概率表达式.其次,通过分析渐近中断概率,发现由于存在非理想CSI导致中断概率在高信噪比区域出现了错误平层.此外,还研究了不同程度的信道估计误差和阴影衰落对系统吞吐量和能量效率的影响.最后,通过数值仿真结果验证了理论推导的正确性和SWIPT NOMA技术引入星地系统所获得的性能增益.展开更多
基金Natural Science Foundation of Gansu Province(23JRRA866)Higher Education Innovation Fund of Gansu Provincial Department of Education(2025A-132)+1 种基金University-level Scientific Research and Innovation Project of Gansu University of Political Science and Law(GZF2024XQN16)Youth Foundation of Lanzhou Jiaotong University(2023023)。
文摘We show that the torsion module Tor_(j)^(R)(R/a,H_(a)^(i)(X))is in a Serre subcategory for the bounded below R-complex X.In addition,we prove the isomorphism Tor_(s-t)^(R)(R/a,X)≅Tor_(s)^(R)(R/a,H_(a)^(t)(X))in some case.As an application,the Betti number of a complex X in a prime ideal p can be computed by the Betti number of the local cohomology modules of X in p.
文摘运用Mawhin重合度理论,讨论一类半直线上三阶多点边值问题(q(t)x″(t))′=f(t,x(t),x′(t),x″(t)),a.e.t∈[0,+∞);■(η■在dim Ker L=2共振情形下的可解性,获得了该边值问题至少存在一个解的充分条件.这里f:[0,1]×R^(3)→R满足L^(1)[0,+∞)-Carathéodory条件,αi,βj∈R(1≤i≤m,1≤j≤n),0<ξ_(1)<ξ_(2)<…<ξ_(m)<+∞,0<η_(1)<η_(2)<…<η_(n)<+∞(m,n∈Z+),q(t)>0,q(t)∈C[0,+∞)∩C^(2)(0,+∞),1/q(t)∈L^(1)[0,+∞).
文摘为了提高星地系统的资源利用率和用户公平性,提出一种无线携能(simultaneous wireless information and power transfer,SWIPT)非正交多址接入(non-orthogonal multiple access,NOMA)技术辅助星地系统的传输方案.首先,在非理想信道状态信息(channel state information,CSI)条件下研究了系统的中断性能,并推导了中断概率表达式.其次,通过分析渐近中断概率,发现由于存在非理想CSI导致中断概率在高信噪比区域出现了错误平层.此外,还研究了不同程度的信道估计误差和阴影衰落对系统吞吐量和能量效率的影响.最后,通过数值仿真结果验证了理论推导的正确性和SWIPT NOMA技术引入星地系统所获得的性能增益.
