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Two-layer Lagrange-based relay network topology and trajectory design for solar system explorations

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Science China(Information Sciences) 2024年第6期67卷 342-358页

作者： jun CAO Jian JIAO hao liu Rongxing LU Qinyu ZHANG Guangdong Provincial Key Laboratory of Aerospace Communication and Networking Technology Harbin Institute of Technology (Shenzhen) Faculty of Computer Science (FCS) University of New Brunswick

Exploration targeting outer planets and even the edge of the solar system is an emerging direction for the deep-space exploration in the next decades. To address this challenge, a novel two-layer Lagrangebased relay network topology is proposed in this study. Specifically, we utilize the Sun-Mars and Sun-Saturn Lagrange points(LPs) L4 and L5 to build a two-layer backbone relay network, which ensures continuous and high-efficiency communication capability for the exploration of the solar system. Furthermore, we utilize the planetary gravity assist and design the transfer trajectory of backbone relays with the help of planetary celestial body motion equations and Kepler's laws. Moreover, we conduct link budget analysis for multihop relay transmission under Gamma-Gamma distribution, shadowed Rician fading, and additive white Gaussian noise channels in several typical exploration scenarios and validate that the LP relays can effectively support future deep-space exploration missions.

关键词： deep-space communication Lagrangian points backbone relay network transfer trajectory relay selection

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龙滩碾压混凝土坝渗流场与应力场耦合分析

四川水力发电 2001年第B07期20卷 54-56,107页

作者：柴军瑞刘浩吾四川大学水电学院四川成都610065

结合龙滩碾压混凝土重力坝的渗透特性 ,考虑碾压混凝土层面渗流及其力学效应以及坝体应力状态对层面渗透性的影响 ,采用碾压混凝土坝渗流场与应力场耦合分析的数学模型及其有限元数值解法 ,对龙滩碾压混凝土重力坝进行了渗流场与应力场... 详细信息

结合龙滩碾压混凝土重力坝的渗透特性 ,考虑碾压混凝土层面渗流及其力学效应以及坝体应力状态对层面渗透性的影响 ,采用碾压混凝土坝渗流场与应力场耦合分析的数学模型及其有限元数值解法 ,对龙滩碾压混凝土重力坝进行了渗流场与应力场耦合分析。

关键词：碾压混凝土坝渗流场应力场耦合分析

Biholomorphic Mappings and the Extension Operators on New Hartogs Domains

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Acta Mathematica Sinica,English Series 2019年第5期35卷 671-689页

作者： Yan Yan CUI Chao jun WANG hao liu College of Mathematics and Statistics Zhoukou Normal University College of Mathematics and Information Science Hebei Normal University Institute of Contemporary Mathematics He’nan University

In this paper, we generalize the Roper–Suffridge operator on the extended Hartogs *** using the geometric properties and the growth theorems of subclasses of biholomorphic mappings,we obtain the generalized operators preserve the properties of parabolic and spirallike mappings of type β and order ρ, S*_Ω(β, A, B), almost starlike mapping of complex order λ on ΩN under different conditions, and thus we get the corresponding results on the unit ball B^n in C^n. The conclusions lead to some known results.

关键词： Biholomorphic mapping Roper-Suffridge operator Hartogs domain

Unequal Forced-Intra-Refresh for robust video streaming

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第10期7卷 1695-1701页

作者： liu hao ZHANG Wen-jun YANG Xiao-kang Institute of lmage Communication and Information Processing Shanghai Jiao Tong University Shanghai 200240 China

For video streaming over lossy channels, intra refresh can mitigate the error-propagation effect caused by packet losses Besides some intra-mode macroblocks （MBs） generated by the ＂Lagrangian rate-distortion＂ or ＂Sum of absolute difference＂ mode decision, the encoder or transcoder possibly needs to increase some ＂forced＂ intra-mode MBs for robust video streaming. Based on the error-propagation analysis in a group of pictures （GOP）, we propose an unequal Forced-Intra-Refresh （FIR） scheme to improve packet loss resilience of video streaming. According to a GOP-level error-propagation model, the proposed unequal FIR scheme can optimally increase the unequal number of forced intra-mode MBs for different frames in a GOP. Simulation results showed that the proposed scheme can effectively enhance the robustness of video streaming under different channel conditions, and achieve about 0. 1-0.9 dB gains over the average FIR scheme in H.264/AVC tools.

关键词： Video streaming Error propagation Intra refresh Packet loss resilience Group of pictures (GOP)

Generalized Quantum Two-Qutrit-State Splitting

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Communications in Theoretical Physics 2008年第10期50卷 873-878页

作者： YUAN hao liu Yi-Min ZHANG Zhan-jun School of Physics ＆ Material Science Anhui University Hefei 230039 China Department of Physics Shaoguan University Shaoguan 512005 China

A three-party scheme for splitting an arbitrary unknown two-qutrit state is proposed,where two non-maximally-entangled three-qutrit states are taken as the quantum channel among three *** the sender'shelp,if and only if both receivers collaborate together,they can securely share the quantum state in a probabilisticway by introducing an ancilla qutrit and performing appropriate unitary *** relation between the successprobability and coefficients characterizing the quantum channel is *** security of the present scheme is analyzedand ***,the generalization of the three-party scheme to more-party case is also sketched.

关键词： generalized quantum state splitting partially entangled state generalized Bell-state measurement single-qutrit projective measurement

Mid-Cretaceous Hainan back-arc basin:record of the sustained extension of South China margin

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Journal of Palaeogeography 2022年第4期11卷 584-600页

作者： Yan Chen jun Meng hao liu Tao liu Ze-Ying Zhao State Key Laboratory of Biogeology and Environmental Geology School of Earth Sciences and ResourcesChina University of Geosciences(Beijing)Beijing100083China School of Ocean Sciences China University of Geosciences(Beijing)Beijing100083China

The continued subduction of the Pacific oceanic lithosphere during the Jurassic-Cretaceous time formed a large magmatic province as“Basin and Range”at the South China ***,the timing and mechanisms of such a huge rifting and magmatism belt are still *** we present new petrological,sedimentological and geochemical analyses for the Cretaceous Lumuwan Formation and coeval intruded mafic dykes under the robust age constrain in Hainan *** results show that the midCretaceous Lumuwan Formation was a typical lacustrine stratigraphic sandwich that accumulated in an intracontinental back-arc extensional *** Hainan mafic dykes(~108-93 Ma)were probably sourced from asthenospheric and lithospheric mantle which were metasomatized by subducted oceanic sediments in a backarc extension of the continental *** timing of the NW-SE-directed back-arc extension in the Hainan Basin has been constrained as 108-93 Ma and played a significant role in the formation of Basin and Range-type tectonics and landscape evolution in the South China.

关键词： Mid-cretaceous Lumuwan Formation Mafic dykes Back-arc extension South China

Scheduling Semiconductor Wafer Fabrication Using a New Harmony Search Algorithm Based on Receipt Priority Interval

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Chinese Journal of Electronics 2016年第5期25卷 866-872页

作者： ZHANG Long liu Min hao Jinghua WANG Xionghai DONG jun College of Electrical Engineering Zhejiang University Department of Automation Tsinghua University

For the scheduling problem of Semiconductor wafer fabrication(SWF), a new Dispatching rule based on the load balance(DRLB) is proposed. Further, a new Harmony search(HS) algorithm based receipt priority interval(HS rpi) is presented to minimize the mean cycle time. A kind of chaotic sequence is used as the harmony vector. Then, a conversion method is designed to convert the real number harmony vector to the mixed vector representing the priorities of all receipts and the algorithm parameters. In order to increase the algorithm robustness and decrease the scale of the scheduling problem, based on receipt priority interval and DRLB, we give a special conversion method used to convert the above mixed vector to the solution of the scheduling problem of SWF. Computational simulations based on the practical instances validate the proposed algorithm.

关键词： Semiconductor wafer fabrication Harmony search algorithm Receipt priority interval Mean cycle time

Effect of Alloying Method on Microstructure and Wear Resistance of Fe-Cr-V-B Based Alloy

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Journal of Iron and Steel Research International 2016年第6期23卷 625-632页

作者： Yu MA Ying liu jun LI Hui ZHANG hao YANG School of Materials Science and Engineering Sichuan University

The microstructure and wear behavior of Fe-Cr-V-B based alloy was *** of the specimens was characterized by metallographic techniques and hardness *** analysis of alloy was performed by X-ray diffraction（XRD）,scanning electron microscopy（SEM）and energy dispersive spectroscopy（EDS）.The results showed that the microstructure of Fe-Cr-V-B based as-cast alloy containing 8.6mass% V was composed ofα-（Fe,Cr）solid solution,VC carbides,and V_3B_4 borides,whereas the as-cast alloy containing 24.8mass% Cr was composed ofα-（Fe,Cr）solid solution and V_3B_4borides;the eutectic V_3B_4 borides mainly comprise M2B-type borides（M presents Fe and Cr）.The existence of a large amount of V atoms affects the growth pattern of eutectic borides,which mainly display rod-like and grainy *** wear behavior of the experimental alloy has been investigated using pin-on-disk type friction and wear *** comparison of experimental results indicated that the relative wear resistance of the alloy containing 8.6mass% V after destabilization heat treatment in a conventional furnace at 1 373 K for 2hwas about six times higher than that of the high chromium（19mass%）cast iron.

关键词： eutectic chromium hardness dispersive vanadium annealed friction annealing coarsen precipitate

Research progress of catalysts for direct coal liquefaction

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Journal of Energy Chemistry 2025年第1期 481-497页

作者： Wei Song Penggao liu Xinyue Chen Ting Wang Chunrong He Rui hao Kaiyu liu State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of Chemistry Xinjiang University College of Chemistry and Chemical Engineering Henan Polytechnic University Hunan Provincial Key Laboratory of Chemical Power Sources College of Chemistry and Chemical Engineering Central South University

Coal direct liquefaction technology is a crucial contemporary coal chemical technology for efficient and clean use of coal resources. The development of direct coal liquefaction technology and the promotion of alternative energy sources are important measures to guarantee energy security and economic security. However, several challenges need to be addressed, including low conversion rate, inadequate oil yield, significant coking, demanding reaction conditions, and high energy consumption. Extensive research has been conducted on these issues, but further exploration is required in certain aspects such as pyrolysis of macromolecules during the liquefaction process, hydrogen activation, catalysts' performance and stability, solvent hydrogenation, as well as interactions between free radicals to understand their mechanisms better. This paper presents a comprehensive analysis of the design strategy for efficient catalysts in coal liquefaction, encompassing the mechanism of coal liquefaction, catalyst construction,and enhancement of catalytic conversion efficiency. It serves as a comprehensive guide for further research endeavors. Firstly, it systematically summarizes the conversion mechanism of direct coal liquefaction, provides detailed descriptions of various catalyst design strategies, and especially outlines the catalytic mechanism. Furthermore, it addresses the challenges and prospects associated with constructing efficient catalysts for direct coal liquefaction based on an understanding of their action mechanisms.

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