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Achieving full mutualism with massive passive devices for multiuser MIMO symbiotic radio

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Science China(Information Sciences) 2024年第9期67卷 196-212页

作者： Jingran XU Zhuoyin DAI Yong ZeNg Shi JIN Tao JIANg National Mobile Communications Research laboratory Southeast University Purple Mountain laboratories Research Center of 6g Mobile Communications School of Cyber Science and Engineering and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

Symbiotic radio(SR) is one of the attractive communication technologies to facilitate largescale Internet of Things(IoT) connections with enhanced energy and spectrum efficiency, where passive backscatter devices(bDs) modulate their information over the radio frequency(RF) signals emitted by the active primary transmitters(PTs). Meanwhile, the primary transmission can be strengthened with the additional multipaths created by bDs. To capitalize to a greater extent on the mutualism relationship between the two types of communication, this paper studies multiple-input multiple-output(MIMO) SR communication systems including multiple PTs and massive bDs. We derive the achievable rate expressions of each PT and bD, as well as the sum rate expressions of primary and secondary communication, *** asymptotic analysis is given to derive the active and passive communication rates with a large number of bDs. Furthermore, for the general case with a finite number of bDs, we study the precoding optimization problem to maximize the sum rate of primary communication, while ensuring that the sum rate of secondary communication and the individual rate for each PT and bD in the prescribed active and passive user sets satisfy the specified thresholds. Simulation results are presented to verify the analytical studies.

关键词： multiuser MIMO SR backscattering massive backscatter devices asymptotic analysis active and passive communication

An ensemble and cost-sensitive learning-based root cause diagnosis scheme for wireless networks with spatially imbalanced user data distribution

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Science China(Information Sciences) 2024年第7期67卷 331-332页

作者： Qi WANg Zhiwen PAN Nan lIU National Mobile Communications Research laboratory Southeast University Purple Mountain laboratories

Root cause diagnosis, a key component of self-healing, plays a vital role in fault management. The spatially imbalanced network key performance indicators (KPIs) reported by users increase the difficulty of identifying root *** [1,2], the image inpainting technique is inspired to address issues caused by sparse reports across the coverage area.

关键词： Wireless networks

Interdigital MnO_(2)/PeDOT Alternating Stacked Microelectrodes for High-Performance On-Chip Microsupercapacitor and Humidity Sensing

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energy & environmental Materials 2024年第2期7卷 257-267页

作者： Muhammad Tahir lihong li liang He Zhongyuan Xiang Zeyu Ma Waqas Ali Haider Xiaoqiao liao Yanlin Song Key laboratory of green Printing CAS Research/Education Centre for Excellence in Molecular SciencesInstitute of Chemistry Chinese Academy of Sciences(ICCAS)Beijing 100190China School of Mechanical engineering Sichuan UniversityChengdu 610065China A.S.Chemical laboratories Inc. Concord L4K 4M4ON Canada

For microelectronic devices,the on-chip microsupercapacitors with facile construction and high performance,are attracting researchers'prior consideration due to their high compatibility with modern ***,we proposed interchanging interdigital Au-/MnO_(2)/polyethylene dioxythiophene stacked microsupercapacitor based on a microfabrication process followed by successive electrochemical *** stacked configuration of two pseudocapacitive active microelectrodes meritoriously leads to an enhanced contact area between MnO_(2)and the conductive and electroactive layer of polyethylene dioxythiophene,hence providing excellent electron transport and diffusion pathways of electrolyte ions,resulting in increased pseudocapacitance of MnO_(2)and polyethylene *** stacked quasi-solid-state microsupercapacitors delivered the maximum specific capacitance of 43 mF cm^(-2)(211.9 F cm^(-3)),an energy density of 3.8μWh cm^(-2)(at a voltage window of 0.8 V)and 5.1μWh cm^(-2)(at a voltage window of 1.0 V)with excellent rate capability(96.6%at 2 mA cm^(-2))and cycling performance of 85.3%retention of initial capacitance after 10000 consecutive cycles at a current density of 5 mA cm^(-2),higher than those of ever reported polyethylene dioxythiophene and MnO_(2)-based planar *** from the favorable morphology,bilayer microsupercapacitor is utilized as a flexible humidity sensor with a response/relaxation time superior to those of some commercially available integrated *** strategy will be of significance in developing high-performance on-chip integrated microsupercapacitors/microsensors at low cost and environment-friendly routes.

关键词： electrochemical polymerization microsensor microsupercapacitor stacked microelectrode

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Slicing capacity-centered mode selection and resource optimization for network-assisted full-duplex cell-free distributed massive MIMO systems

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Science China(Information Sciences) 2024年第1期67卷 203-220页

作者： Jie WANg Jiamin lI Pengcheng ZHU Dongming WANg Hongbiao ZHANg Yue HAO bin SHeNg National Mobile Communications Research laboratory Southeast University 2. Purple Mountain Laboratories China Mobile Research Institute

Network-assisted full-duplex(NAFD) cell-free distributed massive multiple-input multipleoutput(MIMO) systems enable uplink(Ul) and downlink(Dl) communications within the same timefrequency resources,which potentially reduce latency by avoiding the overhead of switching Ul/Dl ***,how to choose Ul/Dl modes remains an important factor affecting system *** the dramatic increase in the number of users and access points(APs),massive access brings significant overhead in the mode ***,the different quality of service(QoS) among users also makes the effective utilization of resources *** one of the most promising technologies in sixth-generation(6g),network slicing enables the adaptive configuration of limited Ul/Dl resources through the resource isolation assisted NAFD ***,we propose a slicing capacity-centered *** this scheme,APs are motivated by slicing requirements and associated slices to form different *** mode selection and resource allocation are performed within each subsystem to reduce overhead and improve resource *** implement this scheme efficiently,a double-layer deep reinforcement learning(DRl)mechanism is used to realize the joint optimization of mode selection and resource *** results show that the slicing capacity-centered scheme can effectively improve resource utilization and reduce overhead.

关键词： network-assisted full-duplex network slicing mode selection resource optimization deep reinforcement learning

Distortion-aware beamforming design for multi-beam satellite communications with nonlinear power amplifiers

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Science China(Information Sciences) 2024年第6期67卷 359-369页

作者： Xiang XIAO li YOU Kezhi WANg Xiqi gAO National Mobile Communications Research laboratory Southeast University Purple Mountain laboratories Department of Computer Science Brunel University London

Hardware components can cause different impairments, including power amplifier(PA) nonlinearities, which inevitably impact the system performance of satellite communications(SATCOM). In this work, we consider a multi-beam SATCOM downlink system and investigate the distortion-aware beamforming scheme with the characteristics of PA non-linearities. Notably, we aim to maximize the resource efficiency(Re), defined as the weighted sum of energy efficiency(ee) with spectral efficiency(Se), to obtain a flexible ee-Se tradeoff while accounting for the characteristics of PA distortion and the total power *** that the optimization objective is a sum of ratios and the high non-convexity involved in constraints,we propose an efficient approach that exploits the quadratic transformation, the lagrange multiplier method,and the gradient ascent approach to handle this issue. Simulation results demonstrate the effectiveness of the distortion-aware beamforming approach in achieving the ee-Se tradeoff and exhibit a substantial Re performance gain over the conventional approach with ideal linear PAs assumed at the satellite transmitters.

关键词： multi-beam satellite communications nonlinear power amplifier energy and spectral efficiency tradeoff resource efficiency robust beamforming

Mitigating set-stuck failure in 3D phase change memory: substituting square pulses with surge pulses

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Science China(Information Sciences) 2024年第5期67卷 295-301页

作者： Ninghua lI Wang CAI Jun XIANg Hao TONg Weiming CHeNg Xiangshui MIAO School of Integrated Circuits Huazhong University of Science and Technology Hubei Yangtze Memory laboratories Hubei Institute of Measurement and Testing Technology

In the devices that integrate phase change memory(PCM) and ovonic threshold switching(OTS),the OTS threshold voltage often surpasses the ReSeT operation voltage of PCM. The conventional application of square pulses hinders the successful completion of the SeT operation in these integrated devices. To address this challenge, a novel pulse called the surge pulse is introduced, which comprises a high amplitude pulse for OTS activation and a low amplitude pulse for PCM operation. by employing COMSOl simulation,the operational effectiveness of both square pulses and surge pulses is validated. Test results reveal that using a square pulse to operate the integrated device accelerates the occurrence of SeT-stuck failure(SSF).In contrast, the surge pulse enables the integrated device to operate for at least 1000 cycles while preserving the essential cyclic characteristics. Additionally, an investigation into the overshoot component of the surge pulse is conducted, revealing that an increase in overshoot amplitude and pulse width also accelerates the emergence of SSF. by applying the theory of ion migration induced by the electric field, the root cause of SSF in integrated devices is explained, and the accuracy of the theory is validated through the application of a reverse pulse. In summary, this study elucidates the rationality of replacing the square pulse with a surge pulse, presenting a superior approach for operating PCM and OTS integrated devices.

关键词： surge pulse phase change memory (PCM) integration SeT-stuck failure (SSF) square pulse

Tau in the pancreas:understanding the link between type 2 diabetes mellitus and Alzheimer's disease

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Signal Transduction and Targeted Therapy 2024年第1期9卷 6-7页

作者： Wenlu li Steffen Tiedt eng H.lo Neuroprotection Research laboratories Departments of Radiology and NeurologyMassachusetts General HospitalHarvard Medical SchoolCharlestownMA02129USA Consortium International pour la Recherche Circadienne sur l’AVC(CIRCA) BostonUSA Institute for Stroke and Dementia Research LMU University HospitalLMU MunichMunichGermany

A recent study published in Molecular Psychiatry proposes a cellular mechanism that may contribute to decreased insulin production in individuals with type 2 diabetes mellitus(T2DM).1 Using a combination of cell culture experiments,animal models and studies in T2DM patients,the authors show that an up-regulation of tau inβ-islet cells can inhibit pancreatic insulin secretion through changes in microtubule assembly.

关键词： T2DM Alzheimer tau

Unified power quality conditioner based on a three-level NPC inverter using fuzzy control techniques for all voltage disturbances compensation

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Frontiers in energy 2014年第2期8卷 221-239页

作者： Salim CHeNNAI M-T beNCHOUIA electrical engineering Department Birine Nuclear Research Center Ain-Oussera W. Djelfa 17200 Algeria l.g.e.b laboratories Electrical Engineering Department Biskra University Biskra 07000 Algeria

This paper presents a novel and efficient control scheme for unified power quality conditioner （UPQC） based on three-level neutral point clamped （NPC） inverter using fuzzy logic techniques. The proposed UPQC is capable of mitigating source current harmonics and compensate all voltage disturbances such as voltage sags, swells, unbalances and harmonics. It is designed by the integration of series and shunt active filters （AFs） sharing a common DC bus capacitor. The DC voltage is maintained constant using proportional integral voltage controller. The synchronous reference frame （SRF） theory is used to get the reference signals for shunt active power filters （APFs） and the power reactive theory （p-q theory） for series APFs. The shunt and series APF reference signals derived from the control algorithm and sensed signals are injected in two controllers to generate switching signals. To improve the UPQC capability, fuzzy logic techniques are introduced to control the series APF. The performances of the proposed UPQC system are evaluated in terms of power factor correction, mitigation of voltage or current harmonics and all other voltage disturbances compensation using Matlab-Simulink software and SimPowerSystem toolbox. The simulation results illustrate the performance of the proposed UPQC at the common connection point of the nonlinear load to improve the power energy quality.

关键词： three-level neutral point clamped (NPC) inverter unified power quality conditioner (UPQC) current

Weathering and accumulation of trace elements in the soils of the Porali Plain, balochistan: repercussions in agriculture

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Acta geochimica 2024年第2期43卷 214-234页

作者： Maria Kaleem erum bashir Shahid Naseem Tahir Rafique bushra Shahab Department of geology University of KarachiKarachi 75270Pakistan Applied Chemistry Research Centre PCSIR Laboratories ComplexKarachi 75280Pakistan

This study is theﬁrst attempt to assess the nature of the soil,especially on the western side of the Porali Plain in balochistan;a new emerging agriculture hub,using weathering and pollution indices supplemented by multi-variate analysis based on geochemical *** outcomes of this study are expected to help farmers in soil manage-ment and selecting suitable crops for the ***-ﬁve soil samples were collected,mainly from the arable land of the Porali *** drying and coning-quarter-ing,soil samples were analyzed for major and trace ele-ments using the XRF technique;sieving and hydrometric methods were employed for granulometric ***-mated data were analyzed using excel,SPSS,and Surfer software to calculate various indices,correlation matrix,and spatial *** granulometric analysis showed that 76%of the samples belonged to loam types of soil,12%to sand type,and 8%to silt *** indices:CIA,CIW,PIA,PWI,WIP,CIX,and ICV were calculated to infer the level of *** indices reﬂect mod-erate to intense weathering;supported by K_(2)O/AI_(2)O_(3),Rb/K_(2)O,Rb/Ti,and Rb/Sr *** of the geo-ac-cumulation and Nemerow Pollution indices pinpoint rela-tively high concentrations of Pb,Ni,and Cr concentration in the *** correlation matrix and Principal Compo-nent Analysis show that the soil in this study area is mainly derived from the weathering of igneous rocks of bela Ophiolite(Cretaceous age)and Jurassic sedimentary rocks of Mor Range having SeDeX/MVT type *** may result in the undesirable accumulation of certain trace elements which adversely affects crops.

关键词： Weathering indices Pollution indices Accumulation Repercussions Trace elements Multivariate analyses Porali Plain balochistan

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