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钨基氮化铀微球弥散燃料制备工艺及性能研究

原子能科学技术 2024年第S01期58卷 96-103页

作者：刘文涛杜江平赵雨梦马春雨刘伟蔡振方中核反应堆辐照特种元件制备工艺重点实验室内蒙古包头014035 中核北方核燃料元件有限公司内蒙古包头014035

金属陶瓷(CERMET)弥散燃料是目前核热推进反应堆用燃料研发热点。氮化铀(UN)微球具有高铀密度、高热导率、高填充率等特点,钨基体具有高熔点、高热导率及低线性热膨胀系数等优点,将两者结合形成的钨基氮化铀微球弥散燃料是空间核动力的... 详细信息

金属陶瓷(CERMET)弥散燃料是目前核热推进反应堆用燃料研发热点。氮化铀(UN)微球具有高铀密度、高热导率、高填充率等特点,钨基体具有高熔点、高热导率及低线性热膨胀系数等优点,将两者结合形成的钨基氮化铀微球弥散燃料是空间核动力的理想候选材料。本文突破了碳热还原-氮化关键难点,成功制备了高纯UN微球,采用无压通氢烧结的工艺路线,实现了钨基UN弥散燃料芯块制备,研究了不同参数对UN微球和弥散燃料芯块性能的影响规律。结果表明,当碳化温度为1900℃、保温时间为8 h、氮化温度为1900℃、保温时间为3 h时,UN微球的纯度最高,达93.79%,相对密度为96%T.D.;以丙三醇为黏结剂、无水乙醇为稀释剂,对UN微球与基体钨粉进行湿混后直接装模压制,UN微球在钨基体中分布较均匀;使用氢气进行致密化烧结,在1900℃可获得95%T.D.以上致密度。对燃料芯块的性能测试表明,钨基UN芯块中的微球完整且分布均匀,微球中U、N原子比为1.04∶1,钨基体与UN微球界面粘附紧密,无分层;随着温度的升高,芯块的导热系数逐渐降低,100℃时的导热系数为182.6 W/(m·K)。

关键词：金属陶瓷燃料氮化铀微球钨基体碳热还原-氮化

Quality Changes of Frozen Meat during Storage and Control Measures

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肉类研究 2010年第6期24卷 86-88页

作者： du jiangping Institute of Food Science and Technology Yunnan Agricultural University Kunming 650201 China

The frozen is a common method of meat storage, generally applications in meat industrial. However, the quality of meat still have taken place changes even in the low temperature, This article discussion on the changes... 详细信息

关键词：肉类冷冻质量管理贮藏方法

Finite-time tracking control of heterogeneous multi-AUV systems with partial measurements and intermittent communication

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Science China(Information Sciences) 2024年第5期67卷 165-182页

作者： Bo CHEN jiangping HU Bijoy Kumar GHOSH School of Automation Engineering University of Electronic Science and Technology of China Key Laboratory of Intelligent Analysis and Decision on Complex Systems Chongqing University of Posts and Telecommunications Yangtze Delta Region Institute (Huzhou) University of Electronic Science and Technology of China Department of Mathematics and Statistics Texas Tech University

The development of a distributed trajectory-tracking control strategy that is independent of velocity measurements is critical to achieving finite-time tracking control of autonomous underwater vehicle(AUV) systems. In this study, a group of heterogeneous AUV systems with intermittent communication links is considered and a finite-time trajectory-tracking control strategy is developed. The strategy includes two observers and one controller proposed for each follower-AUV. The first observer, a hybrid finite-time observer,estimates the state of the leader, whereas the second observer, which relies only on the position measurement,is proposed to estimate the states of the follower-AUV itself. In addition, a distributed trajectory-tracking controller is designed using the states estimated by the intermittent communication network even without velocity measurements. A homogeneous technique is utilized to prove that all followers can track the leader in a finite time. Finally, the effectiveness of the developed finite-time tracking control strategy is illustrated by numerical simulations.

关键词： distributed observer finite-time tracking homogeneous technique intermittent communication multiple heterogeneous AUVs

An artificial interphase enables stable PVDF-based solid-state Li metal batteries

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Nano Research 2024年第3期17卷 1482-1490页

作者： Mengjun Wu jiangping Song Jiaheng Lei Haolin Tang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Department of Chemistry School of ChemistryChemical Engineering and Life SciencesWuhan University of TechnologyWuhan 430070China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Foshan 528200China

Composite polymer electrolytes(CPEs)have attracted much attention for high energy density solid-state lithium-metal batteries owing to their flexibility,low cost,and easy ***,the unstable Li/CPE interface is always challengeable for the practical utilization of ***,a polymer interlayer containing K+prepared by ultraviolet(UV)-curing precursor solution is coated on Li surface to stabilize the interface between poly(vinylidene difluoride)(PVDF)composite electrolytes and Li *** from the physical barrier of the interlayer,the continuous decomposition of PVDF is restrained and the intimate contact between electrode and electrolyte is also achieved to reduce the interface ***,the added K+is utilized to further regulate smooth Li *** a consequence,the symmetric Li|Li cell with coated Li demonstrates steady cycling at 0.4 mAh·cm^(-2) and a high critical current density of 1 mA·cm^(-2).The assembled Li|LiFePO_(4) cell presents outstanding cycling stability(capacity retention of 90%after 400 cycles at 1 C)and good rate *** associated pouch cell performs impressive flexibility and *** work provides a convenient strategy to achieve stable Li/PVDF interface for high-performance PVDF-based solid state Li metal batteries.

关键词： interfacial modification solid-state batteries composite polymer electrolytes interfacial compatibility lithium dendrite

Export and Import Situation of Refractories in China

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China's Refractories 2007年第3期16卷 8-12页

作者： du Weixing HUO jiangping PAN Shangxin FU Lili LI Chaowen Sinosteel Trading Company Beijing 100080 China

China has been the biggest country in production and exporting of refractories. The article describes the problems in the export and import and suggestions on development of refractories. In the future, China will expand its cooperation with world refractories community in science, technology, economy and trade to play a more important role in the international and domestic markets.

关键词： Export Import Refractories Suggestion

Flux phases in the extended Hubbard model on the triangular lattice

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 148-153页

作者： Yuge Chen Kun Jiang Yi Zhang jiangping Hu Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Department of Physics and Institute for Quantum Science and Technology Shanghai UniversityShanghai 200444China Shanghai Key Laboratory of High Temperature Superconductors and International Center of Quantum and Molecular Structures Shanghai UniversityShanghai 200444China Kavli Institute of Theoretical Sciences University of Chinese Academy of SciencesBeijing 100190China New Cornerstone Science Laboratory Beijing 100190China

Using the unrestricted Hartree-Fock variational method,we study the extended Hubbard model in the triangular lattice at 3/4 *** to the nesting instability of the Fermi surface,various density wave states compatible with the 2×2 supercell are found as the ground state by tuning the onsite and nearest neighbor repulsions U and ***,the flux phases with complex bond order parameters are realized in a wide range of the U-V phase *** also acquire nontrivial topological properties due to the spontaneous breaking of the time-reversal *** study suggests that the flux phases can be stabilized by the interplay between short-range repulsive interactions in correlated electron systems.

关键词： flux state triangular lattice Hubbard model

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Charge 4e superconductor: A wavefunction approach

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Science Bulletin 2024年第15期69卷 2328-2331页

作者： Pengfei Li Kun Jiang jiangping Hu Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Kavli Institute of Theoretical Sciences University of Chinese Academy of SciencesBeijing 100190China New Cornerstone Science Laboratory Beijing 100190China

The BCS theory of superconductivity is one of milestones in condensed matter physics, which successfully unveils the nature of this macroscopic quantum phenomenon at a microscopic level[1,2]. The essential ingredients for any superconductors (SCs) are the two-electron Cooper pairs and their phase coherence [2],where electrons bind together two by two and condense to form a coherent quantum state, as illustrated in Fig. 1a.

关键词： quantum superconductor coherent

Safe formation control of multiple unmanned aerial vehicles:control design and safety-stability analysis

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Control Theory and Technology 2024年第3期22卷 442-454页

作者： Haoqi Li jiangping Hu Qingrui Zhou Bijoy K.Ghosh School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313000ZhejiangChina Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100094China Department of Mathematics and Statistics Texas Tech UniversityLubbockTX 79409-1042USA

Both safety and stability are primary performance criteria for multi-unmanned aerial vehicle(multi-UAV)systems in many coordination *** approaches often consider safety and stability *** is necessary and urgent to develop a safety-stability control strategy to merge these two performance *** this paper,a unified approach is developed to consider safety and stability for multi-UAV formation *** stability criterion is represented by a Lyapunov function and safety criterion is represented by a barrier function and then a relaxed converse control Lyapunov-barrier theorem is *** the help of a relaxed converse control Lyapunov-barrier function(RCCLBF),a distributed safety-stability formation control strategy is proposed for the multi-UAV *** transforming the solution of RCCLBF to a Lyapunovlike stabilization problem,we show that the proposed formation control strategy can drive the UAVs staying within a specified safe *** results are provided to validate the proposed safety-stability formation control strategy.

关键词： Multi-UAV system Formation control Lyapunov function Barrier function Stability with safety guarantee

MPI/OpenMP-Based Parallel Solver for Imprint Forming Simulation

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 461-483页

作者： Yang Li jiangping Xu Yun Liu Wen Zhong Fei Wang School of Mechanical Engineering Jiangsu UniversityZhenjiang212016China School of Mechanical Engineering Wuhan Polytechnic UniversityWuhan430023China Shenyang Mint Company Limited Shenyang110092China

In this research,we present the pure open multi-processing(OpenMP),pure message passing interface(MPI),and hybrid MPI/OpenMP parallel solvers within the dynamic explicit central difference algorithm for the coining process to address the challenge of capturing fine relief features of approximately 50 *** such precision demands the utilization of at least 7 million tetrahedron elements,surpassing the capabilities of traditional serial programs previously *** mitigate data races when calculating internal forces,intermediate arrays are introduced within the OpenMP *** helps ensure proper synchronization and avoid conflicts during parallel ***,in the MPI implementation,the coins are partitioned into the desired number of *** division allows for efficient distribution of computational tasks across multiple *** simulation examples are conducted to compare the three solvers with serial programs,evaluating correctness,acceleration ratio,and parallel *** results reveal a relative error of approximately 0.3%in forming force among the parallel and serial solvers,while the predicted insufficient material zones align with experimental ***,speedup ratio and parallel efficiency are assessed for the coining process *** pureMPI parallel solver achieves a maximum acceleration of 9.5 on a single computer(utilizing 12 cores)and the hybrid solver exhibits a speedup ratio of 136 in a cluster(using 6 compute nodes and 12 cores per compute node),showing the strong scalability of the hybrid MPI/OpenMP programming *** approach effectively meets the simulation requirements for commemorative coins with intricate relief patterns.

关键词： Hybrid MPI/OpenMP parallel computing MPI OpenMP imprint forming