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Deflagration and detonation induced by shock wave focusing at different Mach numbers

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Chinese Journal of Aeronautics 2024年第2期37卷 249-258页

作者： Zezhong YANG jun CHENG bo ZHANG School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Shock wave focusing is an effective way to create a hot spot or a high-pressure and hightemperature region at a certain place,showing its unique usage in detonation initiation,which is beneficial for the development of detonation-based *** flame propagation behavior after the autoignition induced by shock wave focusing is crucial to the formation and self-sustaining of the detonation *** this study,wedge reflectors with two different angles(60°and 90°)and a planar reflector are employed,and the Mach number of incident shock waves ranging from 2.0 to 2.8 is utilized to trigger different flame propagation *** pressure transducers and the high-speed schlieren imaging system are both employed to investigate the shock-shock collision and ignition *** results reveal a total of four flame propagation modes:deflagration,DDT(Deflagration-to-Detonation Transition),unsteady detonation,and direct *** detonation wave formed in the DDT and unsteady detonation mode is only approximately 75%-85%of the Chapman-Jouguet(C-J)speed;meanwhile,the directly induced detonation wave speed is close to the C-J *** waves,which are strong evidence for the existence of detonation waves,are discovered in *** usage of wedge reflectors significantly reduces the initial pressure difference ratio needed for direct detonation *** also provide a practical method for differentiating between detonation and deflagration modes,which involves contrasting the speed of the reflected shock wave with the speed of the theoretically nonreactive reflected shock *** findings should serve as a reference for the detonation initiation technique in advanced detonation propulsion engines.

关键词： Deflagration Detonation Hydrogen Ignition Shock wave focusing

Charmless Hadronic Decays B→VV in the Topcolor－Assisted Technicolor Model

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Communications in Theoretical Physics 2003年第1X期40卷 77-84页

作者： XIAOZhen-jun GUOLi-bo DepartmentofPhysics NanjingNormalUniversityNanjing210097China

Based, on the effective Hamiltonian with the generalized factorization approach, we calculate the branching ratios and CP asymmetries of B→VV decays in the Topcolor-assisted Technicolor (TC2) model. Within the considered parameter space we find that: (a) for the pengunin-domdnated B→K^+φ and K^0φ decays, the new physics enhancements to the branching ratios are around 40%; (b) the measured branching branching ratios of B→K^+φ and K^φ decays prefer the range of 3bout half of the Belle's measurement; and (d) for most B→VV decays, the new physics corrections on their CP asymmetries are generally small or moderate in magnittude and insensitive to the variation of m* and Nc^eff.

关键词： B介子介子衰退分支比不对称 QCD 强相互作用

降雨诱发国道G326顺层滑坡破坏与运动过程研究

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三峡大学学报（自然科学版） 2025年第1期47卷 44-49页

作者：刘仕洪宋琨郭磊曹俊姜波贵州省铜仁公路管理局贵州铜仁554200 三峡大学防灾减灾湖北省重点实验室湖北宜昌443002 贵州省交通规划勘察设计研究院股份有限公司贵阳550081

贵州省国道G326松桃县甘龙镇石板村田堡组顺层滑坡是2020年强降雨诱发的滑坡灾害.在对滑坡变形破坏特征调查的基础上,分析了强降雨诱发滑坡滑动破坏的成因.采用物质点法(materialpointmethod,MPM)进行了滑坡运动过程的模拟,揭示了滑坡... 详细信息

贵州省国道G326松桃县甘龙镇石板村田堡组顺层滑坡是2020年强降雨诱发的滑坡灾害.在对滑坡变形破坏特征调查的基础上,分析了强降雨诱发滑坡滑动破坏的成因.采用物质点法(materialpointmethod,MPM)进行了滑坡运动过程的模拟,揭示了滑坡运动的速度和冲击荷载等变化规律.结果表明:国道G326滑坡是受2020年7月8日的强降雨诱发的中型顺层岩质滑坡,在8日4时的小时降雨量为96.2mm后约3h发生整体滑移破坏;物质点法能够较真实地模拟滑坡的运动、堆积过程,模拟的堆积体形态与滑坡破坏调查情况基本一致;滑坡岩土体的最大滑动速度为27m/s,最大滑动动能为1.8×109J(15s左右),最大冲击力为37.98×106kN,位于距滑坡后缘约230m处.该研究对国道G326沿线类似滑坡灾害的风险防控具有参考价值和工程借鉴意义.

关键词：降雨滑坡顺层滑动运动过程模拟物质点法冲击荷载

Active faults and seismogenic models for the Urumqi city,Xinjiang Autonomous Region, China

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Earthquake Science 2016年第3期29卷 173-184页

作者： Yingzhen Li Yang Yu jun Shen bo Shao Gao Qi Mei deng Institute of Disaster Prevention

We have studied the characteristics of the active faults and seismicity in the vicinity of Urumqi city, the capital of Xinjiang Autonomous Region, China, and have proposed a seismogenic model for the assessment of earthquake hazard in this area. Our work is based on an integrated analysis of data from investigations of active faults at the surface, deep seismic reflection soundings, seismic profiles from petroleum exploration, observations of temporal seismic stations, and the precise location of small earthquakes. We have made a comparative study of typical seismogenic structures in the frontal area of the North Tianshan Mountains, where Urumqi city is situated, and have revealed the primary features of the thrust-fold- nappe structure there. We suggest that Urumqi city is comprised two zones of seismotectonics which are inter- preted as thrust-nappe structures. The first is the thrust nappe of the North Tianshan Mountains in the west, con- sisting of the lower （root） thrust fault, middle detachment, and upper fold-uplift at the front. Faults active in the Pleistocene are present in the lower and upper parts of this structure, and the detachment in the middle spreads toward the north. In the future, M7 earthquakes may occur at the root thrust fault, while the seismic risk of frontal fold-uplift at the front will not exceed M6.5. The second structure is the western flank of the arc-like bogda nappe in the east, which is also comprised a root thrust fault, middle detachment, and upper fold-uplift at the front, of which the nappe stretches toward the north; several active faults are also developed in it. The fault active in the Holocene is called the South Fukang fault. It is not in the urban area of Urumqi city. The other three faults are located in the urban area and were active in the late Pleistocene. In these cases, this section of the nappe structure near the city has an earthquake risk of M6.5-7, An earthquake Ms6.6, 60 km east to Urumqi city occurred along the

关键词： Urumqi Active fault Seismogenic structure Thrust Nappe

Local Stability to the Einstein-Euler System in Schwarzschild Space-time

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 352-367页

作者： jun WU bo-ling GUO Institute of Applied Physics and Computational Mathematics Beijing 100088China

We study the Schwarzschild spacetime solutions to the Einstein-Euler *** our analysis,we aim to show local stability under small *** resolve this problem,we use the Nash-Moser(-Hamilton)*** work was originally develop... 详细信息

关键词： schwarzschild metric local stability Nash-Moser(-Hamilton)theorem

Chaotic Synchronization Control based on Finite-time Sliding Model Controller 36

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Chaotic Synchronization Control based on Finite-time Sliding...

Enhanced oxidation resistance of low-carbon MgO-C refractories with ternary carbides:a review

第36届中国控制会议

作者： Gao jun-shan Lan-lan Shi deng Liwei Wu bo Academy of Automation Harbin university of science and technology

ISBN: (纸本)9781538629185

For the problem of the synchronization between two chaotic systems with external disturbances and nonlinear input,based on the Lyapunov’s stability theory and combined the finite time principle with control technology existed,a sliding mode controller was designed by a new type of sliding surface and the corresponding control rule of sliding mode selectivity to achieve the synchronization control of two chaotic systems and make the system reach and maintain the balance state in a limited ***,take Lorenz system and Liu system for example,some MATLAB simulation results verify the feasibility and effectiveness of the sliding mode controller design.

关键词： nonlinear control sliding mode controller finite-time control Lyapunov’s stability theory

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Journal of Iron and Steel Research International 2022年第7期29卷 1052-1062页

作者： Chao Yu bo Dong Yu-feng Chen Bei-yue Ma jun Ding Cheng-ji deng Hong-xi Zhu Jing-hui Di The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

The demand for low-carbon MgO–C refractories is ever growing to meet the development of advanced steelmaking technologies and efficient energy ***,to improve the oxidation resistance and inhibit the weakness of low-carbon MgO–C refractories,antioxidants are *** application of ternary carbides that focused on improving the oxidation performance of MgO–C refractories has been explored,and the ternary carbides including Al_(4)O_(4)C,Al8B_(4)C_(7),Al_(4)SiC_(4),Ti_(2)AlC,Ti_(3)AlC_(2),and Ti_(3)SiC_(2)have been proved *** crystal structure,physical properties,oxidation behavior,and synthesis of these ternary carbides were summarized,and their oxidation mechanism in assisting antioxidation of MgO–C refractories was *** addition,the potential aspects related to the usage and development of ternary carbides in low-carbon MgO–C refractories were proposed.

关键词： Low-carbon MgO–C refractory Ternary carbide MAX phase Oxidation mechanism Oxidation resistance

Current status of percutaneous coronary intervention of chronic total occlusion

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第8期13卷 589-602页

作者： jun-bo GE Department of Cardiology Zhongshan HospitalFudan UniversityShanghai 200032China

This paper describes the current status of percutaneous coronary intervention (PCI) for totally occluded coronary arteries. Chronic total occlusion is associated with 10%-20% of all PCI procedures. Results show that opening an occluded vessel, especially one supplying a considerable area of myocardium, may be beneficial for a patient's angina relief and heart function. We describe the devices used currently in re-canalization such as new wires, microcatheters (including Tonus and Cosair) and intravascular ultrasound guidance. Different techniques to improve the success rate and reduce complications are discussed in detail.

关键词： Percutaneous coronary intervention Chronic total occlusion Retrograde approach

Resource allocation with minimum transmit power in multicast OFDM systems

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Journal of Systems Engineering and Electronics 2010年第3期21卷 355-360页

作者： bo Wu jun Shen Haige Xiang School of Electronics Engineering and Computer Science Peking University Beijing 100871 R R. China

To minimize the total transmit power for multicast service in an orthogonal frequency division multiplexing（OFDM） downlink system,resource allocation algorithms that adaptively allocate subcarriers and bits are *** proposed algorithms select users with good channel conditions for each subcarrier to reduce the transmit power,while guaranteeing each user＇s instantaneous minimum rate *** resource allocation problem is first formulated as an integer programming（IP） problem,and then,a full search algorithm that achieves an optimal solution is *** reduce the computation load,a suboptimal algorithm is *** suboptimal algorithm decouples the joint resource allocation problem by separating subcarrier and bit ***-like algorithms are employed in both *** results illustrate that the proposed algorithms can significantly reduce the transmit power compared with the conventional multicast approach and the performance of the suboptimal algorithm is close to the optimum.

关键词： resource allocation multicast orthogonal frequency division multiplexing (OFDM) integer programming (IP) greedy algorithm.