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国内盾构开舱技术现状与风险管控 被引量:9
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作者 于宝敏 季玉国 《隧道建设(中英文)》 北大核心 2018年第4期165-175,共11页
盾构在长距离掘进后,由于隧道地质的复杂性和工程的特殊性,不可避免地发生刀具磨损和刀盘损坏等现象,此时必须停机进行开舱检修,因此对盾构开舱技术以及刀盘、刀具的修复技术进行研究和总结至关重要。针对盾构开舱以及刀盘、刀具修复难... 盾构在长距离掘进后,由于隧道地质的复杂性和工程的特殊性,不可避免地发生刀具磨损和刀盘损坏等现象,此时必须停机进行开舱检修,因此对盾构开舱技术以及刀盘、刀具的修复技术进行研究和总结至关重要。针对盾构开舱以及刀盘、刀具修复难题,通过实践经验对国内盾构开舱技术现状、开舱的目的和风险进行总结;并以南京扬子江隧道饱和带压换刀作业和地铁盾构开舱为例,分别从两大盾构类型(泥水盾构和土压盾构)对常压开舱和带压开舱技术以及盾构开舱的辅助措施进行分析,详细介绍常压开舱和带压开舱的适用范围、开舱条件、工作原理、作业流程以及开舱的关键技术等。最后,分别以某地铁盾构隧道和南京扬子江隧道的动火修复作业为例,对常压和高压状态下的刀盘动火修复技术进行详细介绍。经过实践总结与分析可知:1)目前国内关于盾构开舱高压下作业的培训及认证体系还不完善,专业队伍比较缺乏,安全生产许可证和业绩评定体系尚不够健全,带压换刀作业手册和管理尚不规范成熟,盾构动火作业的安全形势依然很严峻;2)盾构开舱风险较大,因此应严格加强盾构开舱的风险防范,并应根据具体施工情况尽量做到主动开舱,避免被动开舱;3)目前虽然已成功地在某些工程完成了盾构开舱及刀盘、刀具修复作业,但盾构开舱技术的相关管理体系亟需构建,新技术的开发异常紧迫,因此加强技术交流、加快新技术的研发是一项长期的工作。 展开更多
关键词 盾构开舱 刀具检查 刀具更换 舱内动火作业 风险管控
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完全正则半群的可裂子半群
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作者 余保民 朱天民 《重庆理工大学学报(自然科学)》 CAS 北大核心 2019年第9期233-236,共4页
研究了完全正则半群的可裂子半群。首先利用完全正则半群的结构和性质,研究了完全正则半群的满足条件a1a2a3∈{a1,a2,a3}的子半群的性质,给出了这一类子半群的刻画;在此基础上,结合完全单半群的性质,给出了可裂子半群的刻画。
关键词 完全正则半群 完全单半群 可裂半群 幂等元
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Computable upper bounds for the adiabatic approximation errors 被引量:2
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作者 yu baomin CAO HuaiXin +1 位作者 GUO ZhiHua WANG WenHua 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第11期2031-2038,共8页
For a given Hermitian Hamiltonian H(s)(s∈[0,1])with eigenvalues Ek(s)and the corresponding eigenstates|Ek(s)(1 k N),adiabatic evolution described by the dilated Hamiltonian HT(t):=H(t/T)(t∈[0,T])starting from any fi... For a given Hermitian Hamiltonian H(s)(s∈[0,1])with eigenvalues Ek(s)and the corresponding eigenstates|Ek(s)(1 k N),adiabatic evolution described by the dilated Hamiltonian HT(t):=H(t/T)(t∈[0,T])starting from any fixed eigenstate|En(0)is discussed in this paper.Under the gap-condition that|Ek(s)-En(s)|λ>0 for all s∈[0,1]and all k n,computable upper bounds for the adiabatic approximation errors between the exact solution|ψT(t)and the adiabatic approximation solution|ψadi T(t)to the Schr¨odinger equation i|˙ψT(t)=HT(t)|ψT(t)with the initial condition|ψT(0)=|En(0)are given in terms of fidelity and distance,respectively.As an application,it is proved that when the total evolving time T goes to infinity,|ψT(t)-|ψadi T(t)converges uniformly to zero,which implies that|ψT(t)≈|ψadi T(t)for all t∈[0,T]provided that T is large enough. 展开更多
关键词 adiabatic bounds Hamiltonian fidelity Hermitian dilated numerically exact initially coherent
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An upper bound for the generalized adiabatic approximation error with a superposition initial state
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作者 WANG WenHua CAO HuaiXin +1 位作者 LU Ling yu baomin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第3期1-7,共7页
The classical adiabatic approximation theory gives an adiabatic approximate solution to the Schr6dinger equation (SE) by choosing a single eigenstate of the Hamiltonian as the initial state. The superposition princi... The classical adiabatic approximation theory gives an adiabatic approximate solution to the Schr6dinger equation (SE) by choosing a single eigenstate of the Hamiltonian as the initial state. The superposition principle of quantum states enables us to mathematically discuss the exact solution to the SE starting from a superposition of two different eigenstates of the time-dependent Hamiltonian H(0). Also, we can construct an approximate solution to the SE in terms of the corresponding instantaneous eigenstates of H(t). On the other hand, any physical experiment may bring errors so that the initial state (input state) may be a superposition of different eigenstates, not just at the desired eigenstate. In this paper, we consider the generalized adiabatic evolution of a quantum system starting from a superposition of two different eigenstates of the Hamiltonian at t = 0. A generalized adiabatic approximate solution (GAAS) is constructed and an upper bound for the generalized adiabatic approximation error is given. As an application, the fidelity of the exact solution and the GAAS is estimated. 展开更多
关键词 upper bound ERROR quantum adiabatic approximation
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