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mutual Information Maximization via Joint Power Allocation in Integrated Sensing and Communications Sy.tem

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China Communications 2024年第2期21卷 129-142页

作者： jia Zhu Junsheng mu y.anhao Cui Xiaojun Jing School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper, we focus on the power allocation of Integrated Sensing and Communication(ISAC) with orthogonal frequency.division multiplexing(OFDM) waveform. In order to improve the spectrum utilization efficiency.in ISAC, we propose a design scheme based on spectrum sharing, that is,to maximize the mutual information(MI) of radar sensing while ensuring certain communication rate and transmission power constraints. In the proposed scheme, three cases are considered for the scattering off the target due to the communication signals,as negligible signal, beneficial signal, and interference signal to radar sensing, respectively. thus requiring three power allocation schemes. However,the corresponding power allocation schemes are nonconvex and their closed-form solutions are unavailable as a consequence. Motivated by.this, alternating optimization(AO), sequence convex programming(SCP) and Lagrange multiplier are individually.combined for three suboptimal solutions corresponding with three power allocation schemes. By.combining the three algorithms, we transform the non-convex problem which is difficult to deal with into a convex problem which is easy.to solve and obtain the suboptimal solution of the corresponding optimization problem. Numerical results show that, compared with the allocation results of the existing algorithms, the proposed joint design algorithm significantly.improves the radar performance.

关键词： coexistence communications multicarrier radar mutual information spectrum sharing

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Feature of Motion Around D-stars

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Chinese Phy.ics Letters 1998年第1期15卷 3-4页

作者： LI jia-mu LI Xin-zhou Department of Phy.ics East China University of Science and TechnologyShanghai 200237 East China Institute for Theoretical Phy.ics Shanghai 200237

The motion of test particles around D-stars is investigated by.Hamilton-Jacobi method. There may.exist bound orbits under certain conditions. The trajector with periastrons at large r are Keplerian in form, except for the periastron shift. The trajectory.with periastrons at small r, differ markedly.from Keplerian orbits. The radius of the most tightly.bound is found.

关键词： conditions stars method

Successive MISOCP Algorithm for Islanded Distribution Networks with Soft Open Points

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CSEE Journal of Power and Energy.Sy.tems 2023年第1期9卷 209-220页

作者： Tao Zhang y.nfei mu Hongjie jia Xiny.ng Wang Tianjiao Pu Key.Laboratory.of Smart Grid of Ministry.of Education Key Laboratory of Smart Energy&Information Technology of Tianjin MunicipalityTianjin UniversityTianjin 300072China e China Electric Power Research Institute Beijing 100192China

An optimal operation scheme is of great significance in islanded distribution networks to restore critical loads and has recently.attracted considerable *** this paper,an optimal power flow(OPF)model for islanded distribution networks equipped with soft open points(SOPs)is *** in the grid-connected mode,the adequacy.of local power generation in distribution networks is critical for islanded *** proposed approach utilizes the power output of local distributed generations(DGs)and the benefits of reactive power compensation provided by.SOPs to allow maximum *** exploit the available resources,an optimal secondary.droop control strategy.is introduced for the islanded distribution networks,thereby.minimizing load *** formulated OPF problem is essentially.a mixed-integer nonlinear programming(MINLP)*** guarantee the computation efficiency.and accuracy.A successive mixed-integer second-order cone programming(SMISOCP)algorithm is proposed for handling the nonlinear islanded power flow *** case studies,incorporating a modified IEEE 33-bus sy.tem and IEEE 123-bus sy.tem,are performed to test the effectiveness of the proposed approach.

关键词： Distribution network islanded operation second-order cone programming soft open points successive approximation

Computing top eigenpairs of Hermitizable matrix

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Frontiers of Mathematics in China 2021年第2期16卷 345-379页

作者： mu-Fa CHEN Zhi-Gang jia Hong-Kui PANG Research Institute of Mathematical Science Jiangsu Normal UniversityXuzhou 221116China School of Mathematical Sciences Beijing Normal UniversityBeijing 100875China Laboratory.of Mathematics and Complex Sy.tems(Beijing Normal University. Ministry of EducationBeijing 100875China School of Mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116China

The top eigenpairs at the title mean the maximal, the submaximal, or a few of the subsequent eigenpairs of an Hermitizable matrix. Restricting on top ones is to handle with the matrices having large scale, for which only.little is known up to now. This is different from some mature algorithms, that are clearly.limited only.to medium-sized matrix for calculating full spectrum. It is hoped that a combination of this paper with the earlier works, to be seen soon, may.provide some effective algorithms for computing the spectrum in practice, especially.for matrix mechanics.

关键词： Hermitizable Householder transformation birth-death matrix isospectral matrices top eigenpairs algorithm

Control of ribosome sy.thesis in bacteria:the important role of rRNA chain elongation rate

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Science China(Life Sciences) 2021年第5期64卷 795-802页

作者： Manlu Zhu Haoy.n mu Mengmei jia Lingfu Deng Xiongfeng Dai Hubei Key.Laboratory.of Genetic Regulation and Integrative Biology School of Life SciencesCentral China Normal UniversityWuhan 430079China

Bacteria growth depends crucially.on protein sy.thesis,which is limited by.ribosome *** RNA(rRNA)transcription is the rate-limiting step of ribosome *** is generally.proposed that the transcriptional initiation rate of rRNA operon is the primary.factor that controls the r RNA *** this study.we established a convenient GFP-based reporter approach for measuring the bacterial rRNA chain elongation *** showed that the rRNA chain elongation rate of Escherichia coli remains constant under nutrient limitation and chloramphenicol *** contrast,rRNA chain elongation rate decreases dramatically.under low ***,we found that Vibrio natriegens,the fastest growing bacteria known,has a 50%higher rRNA chain elongation rate than ***,which contributes to its rapid ribosome *** study.demonstrates that r RNA chain elongation rate is another important factor that affects the bacterial ribosome sy.thesis capacity.

关键词： rRNA chain elongation rate ribosome sy.thesis rrn transcriptional initiation rate GFP reporter sy.tem low temperature Vibrio natriegens

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Drift analy.is of MH370 debris in the southern Indian Ocean

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Frontiers of Earth Science 2018年第3期12卷 468-480页

作者： jia GAO Lin mu Xianwen BAO Jun SONG y.ng DING College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao 266100 China National Marine Data and Information Service Tianjin 300171 China College of Marine Science and Technology China University of Geosciences Wuhan 430074 China School of Marine Science and Environment Engineering Dalian Ocean University Dalian 116023 China

Malay.ian Airlines Flight MH370 disappeared on 8 March 2014, while fly.ng from Kuala Lumpur to Beijing. A flaperon from the flight was found on Reunion Island in July.2015. Two more confirmed pieces of debris were found in Mauritius and Tanzania, and 19 unconfirmed items were found off Mozambique, South Africa, and Madagascar. Drift buoy. originating from the designated underwater search area arrived in Reunion Island, Mauritius, and Tanzania. Some of these buoy. took a similarly.long time as did real debris to reach these destinations, following a heading northeast and then west. For the present study. a maritime object drift prediction model was developed. ＂High resolution surface currents, Stokes drift, and winds＂ were processed, and a series of model experiments were constructed. The predicted trajectories of the modeled objects were similar to the observed trajectories of the drift buoy.. Many.modeled objects drifted northward then westward, ending up in Reunion Island, Mauritius, and Tanzania with probabilities of 5%0, 5%0, and 19%o, respectively. At the end of the simulation, most objects were located near 10~S in the western Indian Ocean. There were significant differences between experiments with different leeway.factors, possibly.because of the influence of southeast trade winds. The north part of the underwater search area is most likely.to be the crash site, because the predicted trajectories of objects originating here are consistent with the many.pieces of debris found along the east coast of Africa and the absence of such findings on the west coast of Australia.

关键词： MH370 debris drift trajectory drift buoy. surface currents Stokes drift

multistage strain-hardening behavior of ultrastrong and ductile lightweight refractory.complex-concentrated alloy.

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Journal of Materials Science & Technology 2023年第18期149卷 73-87页

作者： y.efei jia Chang Ren Shiwei Wu y.ngkun mu Long Xu y.ndong jia Wentao y.n Jun y. Gang Wang Institute of Materials Shanghai UniversityShanghai 200444China Zhejiang Institute of Advanced Materials Shanghai UniversityJiashan 314100China Department of Mechanical Engineering National University of Singapore117575Singapore

Lightweight high-entropy.alloy. or complex-concentrated alloy. have demonstrated great potential for engineering applications due to their high strength and ***,a weak strain-hardening ability.and a limited tensile ductility.remain their major ***,a multistage strain-hardening effect is developed to ensure a high strength and still a sufficient ductility.in a rolled and annealed(Ti_(44)V_(28)Zr_(14)Nb_(14))_(98.5)Mo_(1.5)(at.%)lightweight refractory.complex-concentrated alloy.M1.5A-LRCCA).This multistage strain-hardening behavior is related to the microstructure and the corresponding initial aver-age dislocation density.and distribution by.comparison with rolled and annealed Ti_(44)V_(28)Zr_(14)Nb_(14)(M0-LRCCA)and as-cast(Ti_(44)V_(28)Zr_(14)Nb_(14))_(98.5)Mo_(1.5)(M1.5C-LRCCA).The microstructure,with homogeneously.distributed submicron precipitations,a moderate initial average dislocation density.and uniform disloca-tion distribution(e.g.,M1.5A-LRCCA),is susceptible to producing various deformation substructures,such as dislocation substructures(slip bands,Tay.or lattices,microbands,DDWs),shear bands,and deformation twins,which results in the multistage strain-hardening *** method of achieving multistage strain hardening behavior through a microstructure modulation is significant for engineering applications of lightweight high-entropy.alloy. or complex-concentrated alloy.,and it might be extended to other lightweight and high-strength alloy..

关键词： High-entropy.alloy.complex-contracted alloy Lightweight Strain hardening BCC Mechanical properties

Maximum entropy.based probabilistic load flow calculation for power sy.tem integrated with wind power generation

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Journal of Modern Power Sy.tems and Clean Energy 2018年第5期6卷 1042-1054页

作者： Bingy.n SUI Kai HOU Hongjie jia y.nfei mu Xiaodan y. Shanghai Electric Power Design Institute Co. Ltd. School of Electrical and Information Engineering Tianjin University

Distributed generation including wind turbine(WT) and photovoltaic panel increases very.fast in recent y.ars around the world, challenging the conventional way.of probabilistic load flow(PLF) calculation. Reliable and efficient PLF method is required to take this chage into *** paper studies the maximum entropy.probabilistic density.function reconstruction method based on cumulant arithmetic of linearized load flow formulation,and then develops a maximum entropy.based PLF(MEPLF) calculation algorithm for power sy.tem integrated with wind power generation(WPG). Compared with traditional Gram–Charlier expansion based PLF(GC-PLF)calculation method, the proposed ME-PLF calculation algorithm can obtain more reliable and accurate probabilistic density.functions(PDFs) of bus voltages and branch flows in various WT parameter scenarios. It can solve thelimitation of GC-PLF calculation method that mistakenly.gains negative values in tail regions of PDFs. Linear dependence between active and reactive power injections of WPG can also be effectively.considered by.the modified cumulant calculation framework. Accuracy.and efficiency.of the proposed approach are validated with some test sy.tems. Uncertainties y.elded by.the wind speed variations, WT locations, power factor fluctuations are considered.

关键词： Maximum entropy Probabilistic load flow Probability density function Wind power generation Monte Carlo simulation

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选区激光熔化制备高熵合金的研究进展

金属加工(热加工) 2025年第1期 1-12+26页

作者：邱翔宇穆永坤贾延东上海大学材料研究所

高熵合金（HEAs）凭借其多主元特性，展现出远超传统合金的优异性能，然而传统制备方法在高熵合金的生产过程中存在诸多限制。随着先进制造技术的快速发展，选区激光熔化（Selective Laser Melting,SLM）技术在高熵合金的制备中展现出... 详细信息

高熵合金（HEAs）凭借其多主元特性，展现出远超传统合金的优异性能，然而传统制备方法在高熵合金的生产过程中存在诸多限制。随着先进制造技术的快速发展，选区激光熔化（Selective Laser Melting,SLM）技术在高熵合金的制备中展现出显著优势，例如，SLM能够高精度地成形复杂几何结构的高熵合金零件，其独特的高冷却速率特性可显著提升高熵合金的力学性能，因而受到研究者的广泛关注。通过系统介绍了SLM技术的基本原理以及高熵合金粉末的制备方法，总结了SLM制备高熵合金过程中的关键问题，包括缺陷形成、工艺参数优化、合金成分设计，以及后处理手段对材料微观组织和力学性能的影响，研究成果为高熵合金及SLM技术领域的进一步探索提供了理论参考与实践指导。

关键词：选区激光熔化高熵合金微观组织力学性能