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Secure beamforming and deployment design for rate-splitting multiple access-based UAV communications

Science China(Information Sciences) 2025年第1期68卷 342-356页

作者： Bing WANG Xiaofeng TAO Shujun han Huici WU Kai YANG Zhu han National Engineering Research Center of Mobile Network Technologies Beijing University of Posts and Telecommunications Peng Cheng Laboratory Department of Electrical and Computer Engineering University of Houston

Rate-splitting multiple access(RSMA) has recently gained attention as a potential robust multiple access(MA)scheme for upcoming wireless networks. Given its ability to efficiently utilize wireless resources and design interference management strategies, it can be applied to unmanned aerial vehicle(UAV) networks to provide convenient services for large-scale access ground users. However, due to the line-of-sight(LoS) broadcast nature of UAV transmission, information is susceptible to eavesdropping in RSMA-based UAV networks. Moreover, the superposition of signals at the receiver in such networks becomes complicated. To cope with the challenge, we propose a two-user multi-input single-output(MISO) RSMA-based UAV secure transmission framework in downlink communication networks. In a passive eavesdropping scenario, our goal is to maximize the sum secrecy rate by optimizing the transmit beamforming and deployment location of the UAV-base station(UAV-BS),while considering quality-of-service(QoS) constraints, maximum transmit power, and flight space limitations. To address the non-convexity of the proposed problem, the optimization problem is first decoupled into two subproblems. Then, the successive convex approximation(SCA) method is employed to solve each subproblem using different propositions. In addition, an alternating optimization(AO)-based location RSMA(L-RSMA) beamforming algorithm is developed to implement joint optimization to obtain the suboptimal solution. Numerical results demonstrate that(1) the proposed L-RSMA scheme yields a28.97% higher sum secrecy rate than the baseline L-space division multiple access(SDMA) scheme;(2) the proposed L-RSMA scheme improves the security performance by 42.61% compared to the L-non-orthogonal multiple access(NOMA) scheme.

关键词： rate-splitting multiple access UAV communication precoding optimization deployment location physical layer security

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老挝会兰庞雅水电站机组冷却水系统改造

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红水河 2018年第4期37卷 80-82页

作者：刘铁配韩国其中国葛洲坝集团机电建设有限公司四川成都610091

老挝会兰庞雅水电站厂房内安装2台44 MW的冲击式水轮发电机组,机组采用一次循环冷却水系统。电站运行半年后机组冷却水系统管路内壁出现有机质附着物,影响了机组的冷却,导致机组温升过高。为了解决冷却水系统管路内壁附着问题,采用密闭... 详细信息

老挝会兰庞雅水电站厂房内安装2台44 MW的冲击式水轮发电机组,机组采用一次循环冷却水系统。电站运行半年后机组冷却水系统管路内壁出现有机质附着物,影响了机组的冷却,导致机组温升过高。为了解决冷却水系统管路内壁附着问题,采用密闭的二次循环冷却水系统对原冷却水系统进行改造,解决了机组温升过高的问题。

关键词：水轮发电机组冷却水系统技术改造

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复杂环境下钢筋混凝土结构寿命预测研究进展

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混凝土 2023年第8期 8-13,22页

作者：张大利宁作君郑秀梅韩国旗喀什大学土木工程学院新疆喀什844006

基于不同理论的混凝土寿命预测方法对有效确定混凝土预期寿命,为提升混凝土结构全寿命周期可靠性提供了依据,尤其对不同腐蚀环境下混凝土工程的安全使用具有重大意义。盐渍土环境及单盐、复盐、多盐作用下的混凝土腐蚀研究是当前混凝土... 详细信息

基于不同理论的混凝土寿命预测方法对有效确定混凝土预期寿命,为提升混凝土结构全寿命周期可靠性提供了依据,尤其对不同腐蚀环境下混凝土工程的安全使用具有重大意义。盐渍土环境及单盐、复盐、多盐作用下的混凝土腐蚀研究是当前混凝土耐久性研究领域的热点。讨论了基于碳化理论、损伤理论、Fick定律及Weibull概率分布4种寿命期预测理论。以盐渍土环境为研究对象,归纳并总结国内外研究学者在单因素、多因素耦合作用下混凝土寿命期预测模型。依据影响重要性参数的选择、试验模拟环境设计、室外(野外)长期观测试验数据应用等因素提出建立寿命预测理论的未来展望,为腐蚀环境中混凝土寿命期预测技术的纵深研究提供有效的技术支持。

关键词：盐渍土混凝土耐久性损伤模拟试验环境寿命预测模型

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Improvement of Cold Recycled Mixture Performance Based on Improved Density Test Method and RAP Characteristics

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 79-87页

作者： han Zhanchuang PANG Yafeng LIN Hongwei China First Highway Engineering Group Co. LtdBeijing 100024China The Key Laboratory of Road and Traffic Engineering Ministry of EducationTongji UniversityShanghai 201804China Guangzhou Baiyun International Airport Co. Ltd.Guangzhou 510470China

The available test methods for optimal moisture content of cold recycled mixture(CRM)as well as its bulk specific gravity,and theoretical maximum relative density were analyzed in this *** test improvements were suggested to improve test control of the CRM road performance based on the discovered ***,the properties of reclaimed asphalt pavement(RAP),including the content of old asphalt,penetration index,passing rate of 4.75 mm sieve,and gradation change rate after extraction,were *** effects of RAP characteristics on splitting tensile strength,water stability,the high-and low-temperature performance of emulsified asphalt CRM were *** results show that the optimum moisture content of CRM should be determined when the compaction work matches the specimen’s molding *** the analyzed methods of bulk specific gravity assessment,the dry-surface and CoreLok methods provide more robust and accurate results than the wax-sealing method,while the dry-surface method is the most *** modified theoretical maximum relative density test method is proposed,which can reduce the systematic error of the vacuum test *** following RAP-CRM trends can be *** lower the content of old asphalt and the smaller the change rate of gradation,the smaller the voids and the better the water stability of *** greater the penetration of old asphalt,the higher the fracture work and low-temperature splitting *** greater the penetration,the higher the passing rate of 4.75 mm sieve after extraction,and the worse the high-temperature performance of CRM.

关键词： RAP volume parameters high-temperature performance low-temperature performance water stability

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锂渣混凝土气体扩散系数测试分析研究

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混凝土 2017年第6期 44-47,51页

作者：温勇邓雷王渤王晨马丽莎韩国旗新疆大学建筑工程学院新疆乌鲁木齐830047

利用压汞法(MIP)测定混凝土的孔隙率,并结合气体在多孔介质中的扩散机制得出混凝土的复合扩散系数,再根据相关理论推导适用于Autoclam渗透测试仪的气体有效扩散系数计算公式,通过有效扩散系数与复合扩散系数的等式关系得到混凝土的孔曲... 详细信息

利用压汞法(MIP)测定混凝土的孔隙率,并结合气体在多孔介质中的扩散机制得出混凝土的复合扩散系数,再根据相关理论推导适用于Autoclam渗透测试仪的气体有效扩散系数计算公式,通过有效扩散系数与复合扩散系数的等式关系得到混凝土的孔曲折度。研究表明,龄期的延长和强度等级的增加能有效降低总孔隙率并降低锂渣混凝土的孔隙连通性,随着锂渣的掺入,C30、C60混凝土的孔隙率都有所增加且孔曲折度分别在锂渣掺量20%、30%时高于其空白组,从而降低了混凝土的孔连通性。

关键词：锂渣混凝土气体扩散系数孔曲折度

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Crystallization Modulation and Holistic Passivation Enables Efficient Two‑Terminal Perovskite/CuIn(Ga)Se_(2)Tandem Solar Cells

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Nano-Micro Letters 2025年第1期17卷 205-215页

作者： Cong Geng Kuanxiang Zhang Changhua Wang Chung Hsien Wu Jiwen Jiang Fei Long Liyuan han Qifeng han Yi‑Bing Cheng Yong Peng State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070People’s Republic of China Triumph Photovoltaic Materials Co. Ltd.No.1001 Yannan AvenueHigh‑Tech Development DistrictBengbuAnhui 233000People’s Republic of China College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004People’s Republic of China State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)***,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device *** this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK *** addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain ***,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing *** a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our *** validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.

关键词： PVK/CIGS TSCs Irregular rough surfaces Modulating the growth PVK/C60 interface recombination

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锂渣粉对混凝土气体渗透性能的影响

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混凝土 2017年第4期 83-86,90页

作者：邓雷温勇王晨王渤马丽莎韩国旗新疆大学建筑工程学院新疆乌鲁木齐830047

混凝土的耐久性能与孔结构特征有着密切的联系,锂渣粉作为矿物掺合料能有效的改善混凝土的微观结构减轻有害介质的侵入。利用AUTOCLAM渗透性测试仪测试不同龄期的混凝土气体渗透系数的变化,研究水化进程和矿物掺合料对混凝土气体渗透系... 详细信息

混凝土的耐久性能与孔结构特征有着密切的联系,锂渣粉作为矿物掺合料能有效的改善混凝土的微观结构减轻有害介质的侵入。利用AUTOCLAM渗透性测试仪测试不同龄期的混凝土气体渗透系数的变化,研究水化进程和矿物掺合料对混凝土气体渗透系数的影响。试验研究了水灰比分别为0.62、0.45、0.38,纯水泥、锂渣粉取代水泥10%、20%、30%的3、7、14、28 d的各龄期混凝土的强度和气体渗透系数。结果表明锂渣混凝土的气体渗透系数受水灰比和锂渣掺量的影响,当水灰比为0.62时,气体渗透系数随着锂渣掺量的增加而明显增大,锂渣的掺入降低了混凝土的渗透性能,但在20%掺量时有最大的水化速率;水灰比为0.45时,20%掺量能改善混凝土的气体渗透性能,且胶凝材料水化速度更快;对于水灰比0.38的混凝土,锂渣掺量30%混凝土的气体渗透系数略高于空白组混凝土,但有更快的水化速度。

关键词：混凝土锂渣粉气体渗透性

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Unmasking Social Robots’Camouflage:A GNN-Random Forest Framework for Enhanced Detection

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Computers, Materials & Continua 2025年第1期82卷 467-483页

作者： Weijian Fan Chunhua Wang Xiao han Chichen Lin School of Data Science and Intelligent Media Communication University of ChinaBeijing100024China School of Computer and Cyber Sciences Communication University of ChinaBeijing100024China Institute of Communication Studies Communication University of ChinaBeijing100024China State Key Laboratory of Media Convergence and Communication Communication University of ChinaBeijing100024China

The proliferation of robot accounts on social media platforms has posed a significant negative impact,necessitating robust measures to counter network anomalies and safeguard content *** robot detection has emerged as a pivotal yet intricate task,aimed at mitigating the dissemination of misleading *** graphbased approaches have attained remarkable performance in this realm,they grapple with a fundamental limitation:the homogeneity assumption in graph convolution allows social robots to stealthily evade detection by mingling with genuine human *** unravel this challenge and thwart the camouflage tactics,this work proposed an innovative social robot detection framework based on enhanced HOmogeneity and Random Forest(HORFBot).At the core of HORFBot lies a homogeneous graph enhancement strategy,intricately woven with edge-removal techniques,tometiculously dissect the graph intomultiple revealing ***,leveraging the power of contrastive learning,the proposed methodology meticulously trains multiple graph convolutional networks,each honed to discern nuances within these tailored *** culminating stage involves the fusion of these feature-rich base classifiers,harmoniously aggregating their insights to produce a comprehensive detection *** experiments on three social robot detection datasets have shown that this method effectively improves the accuracy of social robot detection and outperforms comparative methods.

关键词： Social robot detection graph neural networks random forest homophily heterophily

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Anomalous quality factor evolution of induced transparency in a virtualized coupled-oscillator system

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 148-155页

作者： Yunhan Yang han Jia Tuo Liu Yuzhen Yang Jun Yang Key Laboratory of Noise and Vibration Research Institute of Acoustics Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences

The phenomenon of induced transparency, characterized by a high quality(Q) factor, holds significant importance in the fields of high-precision sensing, energy storage and wave manipulation. Conventional transparency systems are often constrained by the limited experimentally accessible parameter space and the lack of independent control over intrinsic parameters, thereby hindering advanced research on high-Q effects. Here we propose a virtualized coupled-oscillator system that enables reconfigurable induced transparency in the reflection spectrum. By virtually incorporating a pair of coupled oscillators into an individual acoustic meta-atom, we achieve the manipulation of induced transparency in a decoupled, wide-ranging, and elaborate manner. Exploiting the diverse evolutions across the intrinsic parameter space, we show experimentally a counter-intuitive increase in the Q-factor of the transparency window, which is attributed to the enhanced dissipation of the bright ***, a constant group delay at the center frequency is observed accompanying this evolution. Our work demonstrates an intriguing platform as well as a novel strategy to engineer high-Q induced transparency phenomenon, and paves the way towards applications in programmable acoustic sensors, filters and slow-wave devices.

关键词： induced transparency acoustic meta-atom high quality-factor scattering programmable intrinsic parameter

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A robust statistical prediction model for late-summer heavy precipitation days in North China

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Science China Earth Sciences 2025年第1期68卷 158-171页

作者： Shunli JIANG Tingting han Xin ZHOU Huijun WANG Zhicong YIN Xiaolei SONG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education Nanjing University for Information Science and Technology Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)

Recently, heavy precipitation(HP) events have occurred frequently in North China(NC), causing devastating economic losses and human fatalities. However, the short-term climate prediction of HP is quite limited. Combining year-to-year increment(DY) method and sliding correlations, we developed a robust seasonal prediction model for late-summer HP days(HPDs) in NC during 1982–2022, utilizing three independent predictors—February sea surface temperature(SST) in the Indian Ocean(SST＿IO), February snow depth over North Asia(SDE＿NA), and May melted snow depth in NC(MSDE＿NC). The SST＿IO anomalies affect NC's precipitation through the Pacific-Japan pattern. The SDE＿NA anomalies are associated with East Asian anomalous anticyclone by southeastern propagation of Rossby wave at Eurasia. The MSDE＿NC anomalies are followed by vertical motion and moisture anomalies in situ and thereby cause precipitation anomalies. This prediction model can well simulate the variations of the HPDs, with a correlation coefficient(CC) of 0.81(0.65) between the observed and predicted HPDs＿DY(HPDs＿anomaly). The percentage with the same sign for 15 extreme HPDs＿anomaly years(PSSE) is 100%.Moreover, in the cross-validation test during 1982–2022, the PSSE for HPDs＿anomaly is as high as 100%, along with a low rootmean-square error of 1.14. For independent hindcasts during 2013–2022, the CC between the observed and predicted HPDs＿DY(HPDs＿anomaly) is 0.93(0.83), together with high Nash-Sutcliffe efficiency(0.82) and agreement index(0.89). Specifically, the predictions are broadly consistent with the observations for 2015, 2016, 2017, 2021, and 2022, reflecting excellent performance of this prediction model of HPDs in NC.

关键词： Heavy precipitation at North China Year-to-year increment approach Robust seasonal prediction Sea surface temperature Snow depth

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