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Persistent mixing bursts in the equatorial Pacific thermocline induced by persistent equatorial waves

Journal of Oceanology and Limnology 2024年第2期42卷 492-510页

作者： Jingjing ZHANG Chuanyu LIU Xiang gong Fan WANG School of Mathematics and Physics Qingdao University of Science and TechnologyQingdao 266100China Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China

A recent study by Liu et al.(2020)suggested that due to the saturation of equatorially trapped planetary waves with different dynamical types,temporal periods,meridional and baroclinic modes,complex layer structures of vertical velocity shear and hence turbulent mixing could frequently occur in the thermocline of the eastern equatorial *** investigated the occurrence of the interior turbulent mixing as indicated by shear instabilities,above the Equatorial Undercurrent(EUC)core at three equatorial sites along 140°W,170°W,and 165°E,respectively,based mainly on data from the Tropical Atmosphere and Ocean(TAO)mooring *** found that turbulent mixing bursts persisted in the thermocline of all three ***,the interior turbulent mixing layers(ITMLs)could occur in probability of approximately 68%,53%,and 48%at the three sites,*** overall occurrence probability shows obvious and similar biannual variations at 140°W and 170°W,which is higher in boreal from late summer to winter and lower in ***,the ITMLs are primarily located above the EUC core and prevail in deeper(shallower)layers from late summer to winter(spring).Most ITMLs(70%)lasted for hours to 3 days,and a few of them(15%)for more than 7 *** thicknesses of ITMLs were concentrated between 15 and 55 *** 165°E,the vertical distribution of ITML occurrence probability was different from that at 140°W and 170°W,as it did not show a preference for depths;the durations of ITMLs are short(also from hours to several days)and their thicknesses were between 5 and 25 *** properties,particularly the high occurrence probability,and short durations demonstrated the persistence of thermocline mixing in the western to eastern equatorial Pacific thermocline and confirmed the generation mechanism by persistent equatorial waves as well.

关键词： interior turbulent mixing layer(ITML) weakly sheared layer(WSL) Equatorial Undercurrent(EUC)core occurrence probability seasonality

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BAD-FM:Backdoor Attacks Against Factorization-Machine Based Neural Network for Tabular Data Prediction

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Chinese Journal of Electronics 2024年第4期33卷 1077-1092页

作者： Lingshuo MENG Xueluan gong Yanjiao CHEN College of Electrical Engineering Zhejiang University School of Computer Science Wuhan University

Backdoor attacks pose great threats to deep neural network models. All existing backdoor attacks are designed for unstructured data(image, voice, and text), but not structured tabular data, which has wide real-world applications, e.g., recommendation systems, fraud detection, and click-through rate prediction. To bridge this research gap, we make the first attempt to design a backdoor attack framework, named BAD-FM, for tabular data prediction models. Unlike images or voice samples composed of homogeneous pixels or signals with continuous values, tabular data samples contain well-defined heterogeneous fields that are usually sparse and discrete. Tabular data prediction models do not solely rely on deep networks but combine shallow components(e.g., factorization machine, FM) with deep components to capture sophisticated feature interactions among fields. To tailor the backdoor attack framework to tabular data models, we carefully design field selection and trigger formation algorithms to intensify the influence of the trigger on the backdoored model. We evaluate BAD-FM with extensive experiments on four datasets, i.e.,HUAWEI, Criteo, Avazu, and KDD. The results show that BAD-FM can achieve an attack success rate as high as 100%at a poisoning ratio of 0.001%, outperforming baselines adapted from existing backdoor attacks against unstructured data models. As tabular data prediction models are widely adopted in finance and commerce, our work may raise alarms on the potential risks of these models and spur future research on defenses.

关键词： Adaptation models Systematics Frequency modulation Finance Predictive models Prediction algorithms Data models

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Hybrid Beamforming Design and Signal Processing with Fully-Connected Architecture for mmWave Integrated Sensing and Communications

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Journal of Communications and Information Networks 2024年第2期9卷 151-161页

作者： Hongyu Li Jun gong Wenchi Cheng The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050080China State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

Millimeter-wave (mmWave) is capable of achieving gigabit/second communication capacity and centimeter-level sensing accuracy and has become one of the main frequency bands for integrated sensing and communications (ISAC) research. Hybrid beamforming techniques have attracted much attention for solving the high path loss of mmWave and further reducing the hardware cost of the system. However, the related studies based on multicarrier and fully-connected hybrid architectures are still limited. For this reason,this paper investigates the orthogonal frequency division multiplexing (OFDM) based mmWave fully-connected hybrid architecture ISAC system to form a stable communication beam and dynamically varying sensing beam. In order to realize the aforementioned multifunctional beams, the hybrid beamformer design problem based on weighted error minimization of multicarrier is proposed and solved efficiently using the penalty dual decomposition (PDD) algorithm. Meanwhile, based on the echo model, the multicarrier multiple signal classification (MUSIC) algorithm for target angle of arrival estimation and the two-dimensional discrete Fourier transform(2D-DFT)algorithm for distance and velocity estimation are proposed, respectively. Numerical simulation results show that by adjusting the weighting factor,a flexible trade-off can be formed between the communication spectrum efficiency and the sensing accuracy error.

关键词： integrated sensing and communications hybrid beamforming fully-connected architecture millimeter-wave

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准噶尔盆地西北缘中三叠统克拉玛依组烃源岩生烃潜力

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中国矿业大学学报 2020年第2期49卷 328-340页

作者：龚德瑜王绪龙周川闽陈棡吴卫安刘银河中国石油勘探开发研究院北京100083 中国石油新疆油田公司新疆克拉玛依834000

准噶尔盆地西北缘中三叠统克拉玛依组发育有煤系(主要为炭质泥岩和煤)和湖相泥岩两种不同类型的烃源岩.通过TOC,热解,生物标志物和有机岩石学分析后认为克拉玛依组湖相泥岩是一套弱氧化-弱还原条件下的微咸水沉积,而煤系烃源岩则主要是... 详细信息

准噶尔盆地西北缘中三叠统克拉玛依组发育有煤系(主要为炭质泥岩和煤)和湖相泥岩两种不同类型的烃源岩.通过TOC,热解,生物标志物和有机岩石学分析后认为克拉玛依组湖相泥岩是一套弱氧化-弱还原条件下的微咸水沉积,而煤系烃源岩则主要是一套弱氧化-弱还原环境下的淡水沉积.研究结果表明:两类烃源岩有机质以陆源高等植物输入为主,同时还有一定比例的藻类和微生物.烃源岩的氢指数平均216 mg/g,H/C原子比平均0.79,有机质类型均为Ⅱ2-Ⅲ型,除生气外,还具有一定的生油能力.克拉玛依组湖相泥岩总体属于中等-好的生油岩,部分达到极好生油岩,丰度高于白碱滩组湖相泥岩;而克拉玛依组煤系烃源岩总体属于中等生油岩.烃源岩镜质体反射率和Tmax均较低(0.41%~0.85%和419~449℃),抽提物甾烷异构体未达到平衡值(C29甾烷20S/(20S+20R)=0.08~0.42;C29甾烷ββ/(ββ+αα)=0.13~0.48),说明总体处于未成熟-低成熟阶段.盆地模拟表明西北缘克拉玛依组成熟有效源灶仅在玛湖凹陷中心部位局限分布,是研究区一套次要的烃源岩.从全盆地来看,克拉玛依组成熟有效源灶的分布范围仍十分可观,有望今后成为准噶尔盆地一个重要的勘探接替领域.

关键词：准噶尔盆地三叠系克拉玛依组煤系烃源岩湖相烃源岩生烃潜力

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Rockburst proneness considering energy characteristics and sample shape effects

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2441-2465页

作者： Song Luo Fengqiang gong Kang Peng Zhixiang Liu School of Resources and Safety Engineering Central South UniversityChangsha410083China School of Civil Engineering Southeast UniversityNanjing211189China

Accurate prediction of rockburst proneness is one of challenges for assessing the rockburst risk and selecting effective control *** study aims to assess rockburst proneness by considering the energy characteristics and qualitative information during rock *** representative rock types in cylindrical and cuboidal sample shapes were tested under uniaxial compression conditions and the failure progress was detected by a high-speed *** far-field ejection mass ratio(FEMR)was determined considering the qualitative failure information of the rock *** peak-strength energy impact index and the residual elastic energy index were used to quantitatively evaluate the rockburst proneness of both cylindrical and cuboidal ***,the performance of these two indices was analyzed by comparing their estimates with the *** results show that the accuracy of the residual elastic energy index is significantly higher than that of the peak-strength energy impact *** residual elastic energy index and the FEMR are in good agreement for both cylindrical and cuboidal rock *** is because these two indices can essentially reflect the common energy release mechanism characterized by the mass,ejection velocity,and ejection distance of rock *** suggests that both the FEMR and the residual elastic energy index can be used to accurately measure the rockburst proneness of cylindrical and cuboidal samples based on uniaxial compression test.

关键词： Rockburst proneness Sample shape Strain energy Energy release Far-field ejection mass ratio(FEMR)

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Research,application and development of inorganic binder for casting process

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China Foundry 2024年第5期21卷 461-475页

作者： Xiao-long gong Sheng-li Hu Zi-tian Fan State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Inorganic binder used in casting process has the advantages of low odor,labor-friendly conditions,and relatively low cost,which is one of the main development directions for casting molding materials in the ***,compared to organic binders(such as resin binders),inorganic binders exhibit lower bonding strength and are more sensitive to environmental *** sensitivity poses challenges,particularly in the reclamation of used sand,thus limiting their broader *** this paper,the research and application status of inorganic binders(mainly silicate inorganic binders)and their curing methods are *** addition,the research and application of phosphate inorganic binders and 3D printing inorganic binders that are being developed are ***,a detailed comparative analysis is conducted on the challenging issue of“reclamation for used sand”in the application of inorganic ***,the development direction of inorganic binders is clarified.

关键词： inorganic binder silicate system phosphate system 3D printing used sand reclamation development trend

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Optical coherence tomography angiography metrics in different stages of diabetic macular edema

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Eye and Vision 2024年第3期10卷 13-20页

作者： Ruyi Han Ruowen gong Wei Liu Gezhi Xu Eye Institute and Department of Ophthalmology Eye and ENT Hospital of Fudan University83 Fenyang RoadShanghai200031People’s Republic of China Key Laboratory of Visual Impairment and Restoration Fudan UniversityShanghaiPeople’s Republic of China Key Laboratory of Myopia(Fudan University) Chinese Academy of Medical SciencesNational Health CommissionShanghaiPeople’s Republic of China

Background To investigate the optical coherence tomography angiography(OCTA)characteristics of diabetic macular edema(DME)at different *** This study was a cross-sectional *** diagnosed with DME were *** was classified into early,advanced,and severe *** vessel density(VD)in the superficial vascular plexus(SVP),deep vascular plexus(DVP)and foveal avascular zone(FAZ)parameters,including FAZ area,FAZ perimeter,acircularity index and foveal VD in a 300-μm-wide region around the FAZ(FD-300),were calculated by the AngioVue software.A multivariate generalized estimating equation was used to evaluate the associations between visual acuity and OCTA *** Ninety-two eyes from 74 patients with DME were included in this *** to early(P=0.006)and advanced DME(P=0.003),the acircularity index was higher in severe *** whole and parafoveal VD in the DVP decreased in eyes with severe DME compared to early DME(P=0.018,P=0.005,respectively)and advanced DME(P=0.035,P=0.012,respectively).In the multivariate generalized estimating equation,DME severity,FAZ area and foveal thickness were positively associated with worse visual acuity(P=0.001,P=0.007 and P=0.001,respectively).Conclusion Compared to early and advanced DME,severe DME showed increased irregularity in the FAZ and more extensive vessel damage in the *** severity level of DME,larger FAZ area,and increased foveal thickness could be risk factors for poor visual *** registration The protocol was published in the Chinese Clinical Trial Registry(ChiCTR2000033082).

关键词： Optical coherence tomography angiography Diabetic macular edema Vessel density Acircularity index

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Fast fixed-time three-dimensional terminal guidance with non-concave trajectory constraint

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Chinese Journal of Aeronautics 2024年第3期37卷 208-218页

作者： Youmin gong Yanning GUO Yueyong LYU Dongyu LI Guangfu MA Department of Control Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Cyber Science and Technology Beihang UniversityBeijing 100191China

Focusing on the non-concave trajectory constraint,a sliding-mode-based nonsingular feedback fast fixed-time three-dimensional terminal guidance of rotor unmanned aerial vehicle landing,planetary landing and spacecraft rendezvous and docking terminal phase with external disturbance is investigated in this ***,a fixed-time observer based on real-time differentiator is developed to compensate for the external disturbance,whose estimation error can converge to zero after a time independent of the initial ***,a sliding surface ensuring fixed-time convergence is *** sliding surface can guarantee that the vehicle achieves a non-concave trajectory,which is better for avoiding collision and maintaining the visibility of the landing site or docking ***,the nonsingular guidance ensuring the fixed-time convergence of the sliding surface is proposed,which is continuous and chatter *** last,three numerical simulations of Mars landing are performed to validate the effectiveness and correctness of the designed scheme.

关键词： Three-dimensional Terminal guidance Non-concave trajectory constraint Fast fixed-time control Sliding mode control

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Room-temperature ferroelectricity in van der Waals SnP_(2)S_(6)

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Frontiers of physics 2024年第4期19卷 113-123页

作者： Chaowei He Jiantian Zhang Li gong Peng Yu State Key Laboratory of Optoelectronic Materials and Technologies Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices Nanotechnology Research Center School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Instrumental Analysis and Research Center Sun Yat-sen UniversityGuangzhou 510275China

Two-dimensional(2D)ferroelectric materials,which possess electrically switchable spontaneous polarization and can be easily integrated with semiconductor technologies,is of utmost importance in the advancement of high-integration low-power *** the experimental discovery of certain 2D ferroelectric materials such as CuInP2S6 and In2Se3,achieving stable ferroelectricity at room temperature in these materials continues to present a significant ***,stable ferroelectric order at room temperature in the 2D limit is demonstrated in van der Waals SnP_(2)S_(6) atom layers,which can be fabricated via mechanical exfoliation of bulk SnP_(2)S_(6) *** polarization is observed in thin SnP_(2)S_(6) of~7 ***,a van der Waals ferroelectric field-effect transistor(Fe-FET)with ferroelectric SnP_(2)S_(6) as top-gate insulator and ptype WTe0.6Se1.4 as the channel was designed and fabricated successfully,which exhibits a clear clockwise hysteresis loop in transfer characteristics,demonstrating ferroelectric properties of SnP_(2)S_(6) atomic *** addition,a multilayer graphene/SnP_(2)S_(6)/multilayer graphene van der Waals vertical heterostructure phototransistor was also fabricated successfully,exhibiting improved optoelectronic performances with a responsivity(R)of 2.9 A/W and a detectivity(D)of 1.4×10^(12) *** results show that SnP_(2)S_(6) is a promising 2D ferroelectric material for ferroelectric-integrated low-power 2D devices.

关键词： two-dimensional ferroelectric materials ferroelectric fieldeffect transistors photodetectors

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From tunnel boring machine to tunnel boring robot: perspectives on intelligent shield machine and its smart operation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第5期25卷 357-381页

作者： Yakun ZHANG Guofang gong Huayong YANG Jianbin LI Liujie JING State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China China Railway Engineering Equipment Group Co. Lid.Zhengzhou 450016China Maha Fluid Power Research Center Purdue UniversityWest LafayetteIN 47905USA

Advances in intelligent shield machines reflect an evolving trend from traditional tunnel boring machines(TBMs)to tunnel boring robots(TBRs).This shift aims to address the challenges encountered by the conventional shield machine industry arising from construction environment and manual *** study presents a systematic review of intelligent shield machine technology,with a particular emphasis on its smart ***,the definition,meaning,contents,and development modes of intelligent shield machines are *** development status of the intelligent shield machine and its smart operation are then *** analyzing the operation process of the shield machine,an autonomous operation framework considering both stand-alone and fleet levels is *** and recommendations are given for achieving autonomous *** study offers insights into the essence and developmental framework of intelligent shield machines to propel the advancement of this technology.

关键词： Intelligent shield machine Tunnel boring machine(TBM) Tunnel boring robot(TBR) Self-driving Autonomous control Shield machine

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