The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurem...The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of the^(232)Th(n,f)cross sec-tion relative to^(235)U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source(Back-n).The fission event-neutron energy spectra of^(232)Th and^(235)U fission cells were measured in the single-bunch mode.Corrected 232Th/235U fission cross-sectional ratios were obtained,and the measurement uncertainties were 2.5–3.7%for energies in the 2–20 MeV range and 3.6–6.2%for energies in the 20–200 MeV range.The^(232)Th(n,f)cross section was obtained by introducing the standard cross section of^(235)U(n,f).The results were compared with those of previous theoreti-cal calculations,measurements,and evaluations.The measured 232Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty,and 232Th fission resonances were observed in the 1–3 MeV range.The present results provide^(232)Th(n,f)cross-sectional data for the evaluation and design of Th/U cycle nuclear systems.展开更多
IEEE802.16e is the major global cellular wireless standard that enables low-cost mobile Internet application. However, existing handover process system still has latency affects time-sensitive applications. In this pa...IEEE802.16e is the major global cellular wireless standard that enables low-cost mobile Internet application. However, existing handover process system still has latency affects time-sensitive applications. In this paper, the handover procedures of 802.16e and Fast Handover for Hierarchical MIPv6 (F-HMIPv6) are reconstructed to achieve a better transmission performance. The concept of cross layer design is adopted to refine the existing handover procedure specified in 802.16e MAC layer and F-HMIPv6. More specifically, layer2 and layer3 signaling messages for handover are analyzed and combined/interleaved to optimize the handover performance. Extensive simulations show that the proposed scheme in this paper is superior to the other scheme proposed by IETF.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11675155,11790321,and 12075216)the National Key Research and Development Plan(No.2016YFA0401603).
文摘The ^(232)Th(n,f)cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle.Using the time-of-flight method and a multi-cell fast-fission ionization chamber,a novel measurement of the^(232)Th(n,f)cross sec-tion relative to^(235)U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source(Back-n).The fission event-neutron energy spectra of^(232)Th and^(235)U fission cells were measured in the single-bunch mode.Corrected 232Th/235U fission cross-sectional ratios were obtained,and the measurement uncertainties were 2.5–3.7%for energies in the 2–20 MeV range and 3.6–6.2%for energies in the 20–200 MeV range.The^(232)Th(n,f)cross section was obtained by introducing the standard cross section of^(235)U(n,f).The results were compared with those of previous theoreti-cal calculations,measurements,and evaluations.The measured 232Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty,and 232Th fission resonances were observed in the 1–3 MeV range.The present results provide^(232)Th(n,f)cross-sectional data for the evaluation and design of Th/U cycle nuclear systems.
文摘IEEE802.16e is the major global cellular wireless standard that enables low-cost mobile Internet application. However, existing handover process system still has latency affects time-sensitive applications. In this paper, the handover procedures of 802.16e and Fast Handover for Hierarchical MIPv6 (F-HMIPv6) are reconstructed to achieve a better transmission performance. The concept of cross layer design is adopted to refine the existing handover procedure specified in 802.16e MAC layer and F-HMIPv6. More specifically, layer2 and layer3 signaling messages for handover are analyzed and combined/interleaved to optimize the handover performance. Extensive simulations show that the proposed scheme in this paper is superior to the other scheme proposed by IETF.
