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Modulators for Terahertz Communication: The Current State of the Art

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Research 2019年第1期2019卷 895-916页

作者： Z.T.Ma Z.X.Geng Z.Y.Fan J.Liu h.d.chen College of Science Minzu University of ChinaBeijing 100081China School of Information Engineering Minzu University of ChinaBeijing 100081China State Key Laboratory for Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

With the increase of communication frequency,terahertz(Thz)communication technology has been an important research feld;particularly the terahertz modulator is becoming one of the core devices in Thz communication *** modulation performance of a Thz communication system depends on the characterization of Thz *** modulators based on diferent principles and materials have been studied and ***,they are still on the way to practical application due to low modulation speed,narrow bandwidth,and insufcient modulation ***,we review the research progress of Thz modulator in recent years and evaluate devices critically and *** focus on the working principles such as electric,optical,optoelectrical,thermal,magnetic,programmable metamaterials and nonlinear modulation methods for Thz wave with semiconductors,metamaterials,and 2d materials(such as graphene,molybdenum disulfde,and tungsten disulfde).Furthermore,we propose a guiding rule to select appropriate materials and modulation methods for specifc applications in Thz communication.

关键词： modulator communication narrow

A perspective on greenhouse gas emission studies integrating arbuscular mycorrhiza

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Pedosphere 2024年第3期34卷 525-529页

作者： Stavros d.VERESOGLOU Junjiang chen State Key Laboratory of Biocontrol School of EcologySun Yat-sen UniversityShenzhen 518107(China)

Climate change is a global *** is only possible to pace down global change through addressing the triggers of it,greenhouse gas *** commendable progress,we think that there is plenty of room to further make the studies addressing global change realistic,through integrating into them biotic *** make a case for this statement through a bibliometrics analysis on agricultural studies exploring greenhouse gas emissions that consider arbuscular *** show that even though mycorrhizal studies account right now for a small fraction of the agricultural literature,they get cited more *** further demonstrate that mycorrhizal studies are typically more descriptive in their nature,which we support through comparing the keywords they *** subsequently use the opportunity to identify shortcomings and opportunities to further integrate mycorrhiza into agricultural studies assaying greenhouse gas *** finally make a call to better integrate arbuscular mycorrhiza into global change studies.

关键词： bibliometric analysis biochemical models global change biology Glomeromycota sustainable agricultural intensification

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped hfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X chen M M chen Y Liu d W Cao G J chen department of Microelectronics Jiangsu UniversityZhenjiang 212013China department of Physics Jiangsu UniversityZhenjiang 212013China Guangdong–hong Kong–Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric hfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)hfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric hfO_(2)thin ***,the crystallization of o-phase hfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped hfO_(2)(hfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic hfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase hfO_(2)in the as-grown hfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase hfO_(2),which further thermally stabilizes the o-phase hfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric hfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain hfO_(2)

Estimating Critical Clearing Time of Grid Faults Using dA of State-Reduction Model of Power Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 807-820页

作者： Yang Liu Zhongyang chen huanjin Yao Lin Yi Q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China China Southern Power Grid Research Institute Guangzhou 510663China

This paper proposes a critical clearing time (CCT) estimation method by the domain of attraction (dA) of a state-reduction model of power systems using sum of squares (SOS) programming. By exploiting the property of the Jacobian matrix and the structure of the boundary of the dA, it is found the dA of the state-reduction model and that of the full model of a power system are topological isomorphism. There are one-to-one correspondence relationships between the number of equilibrium points, the type of equilibrium points, and solutions of the two system models. Based on these findings, an expanding interior algorithm is proposed with SOS programming to estimate the dA of the state-reduction model. State trajectories of the full model can be transformed to those of the state-reduction model by orthogonal or equiradius projection. In this way, CCT of a grid fault is estimated with the dA of the state-reduction model. The calculational burden of SOS programming in the dA estimation using the state-reduction model is rather small compared with using the full model. Simulation results show the proposed expanding interior algorithm is able to provide a tight estimation of dA of power systems with higher accuracy and lower time costs.

关键词： Critical clearing time domain of attraction expanding interior algorithm state-reduction model SOS programming

dual Additives for Stabilizing Li deposition and SEI Formation in Anode-Free Li-Metal Batteries

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Energy & Environmental Materials 2024年第3期7卷 84-92页

作者： Baolin Wu Chunguang chen dmitri L.danilov Zhiqiang chen Ming Jiang Rüdiger-A.Eichel Peter h.L.Notten Forschungszentrum Jülich(IEK-9) D-52425Jülich Germany RWTh Aachen University D-52074Aachen Germany LNM Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100049China Eindhoven University of Technology P.O.Box 5135600 MBEindhoven The Netherlands School of Electronics and Information Institute of Carbon Neutrality and New EnergyHangzhou Dianzi UniversityHangzhou 310018China University of Technology Sydney BroadwaySydney NSW 2007Australia

Anode-free Li-metal batteries are of significant interest to energy storage industries due to their intrinsically high ***,the accumulative Li dendrites and dead Li continuously consume active Li during *** results in a short lifetime and low Coulombic efficiency of anode-free Li-metal *** effective electrolyte additives can improve the Li deposition homogeneity and solid electrolyte interphase(SEI)stability for anode-free Li-metal ***,we reveal that introducing dual additives,composed of LiAsF6 and fluoroethylene carbonate,into a low-cost commercial carbonate electrolyte will boost the cycle life and average Coulombic efficiency of NMC‖Cu anode-free Li-metal *** NMC‖Cu anode-free Li-metal batteries with the dual additives exhibit a capacity retention of about 75%after 50 cycles,much higher than those with bare electrolytes(35%).The average Coulombic efficiency of the NMC‖Cu anode-free Li-metal batteries with additives can maintain 98.3%over 100 *** contrast,the average Coulombic efficiency without additives rapidly decline to 97%after only 50 *** situ Raman measurements reveal that the prepared dual additives facilitate denser and smoother Li morphology during Li *** dual additives significantly suppress the Li dendrite growth,enabling stable SEI formation on anode and cathode *** results provide a broad view of developing low-cost and high-effective functional electrolytes for high-energy and long-life anode-free Li-metal batteries.

关键词： anode-free lithium metal battery dual additives in situ Raman Li growth SEI formation

Single-pilot operations in commercial flight:Effects on neural activity and visual behaviour under abnormalities and emergencies

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Chinese Journal of Aeronautics 2024年第8期37卷 277-292页

作者： Qinbiao LI Chun-hsien chen Kam K.h.NG Xin YUAN Cho Yin YIU human Factors and Ergonomics Laboratory Department of Aeronautical and Aviation EngineeringThe Hong Kong Polytechnic UniversityHong Kong Special Administrative Region 100872China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

With cutting-edge technologies and considering airline human-resource-saving,a single pilot in commercial jets could be technically *** changes in captains’natural behaviours are initially required to comprehend the specific safe human performance envelope for safeguarding single-pilot flight,particularly in high-risk *** paper investigates how captains’performance transforms for fixing emergencies when operating from dual-Pilot Operations(dPO)to Single-Pilot Operations(SPO)through a physiological-based *** pilots flew an emergency-included flight with/without first officers’*** neural activities and scanning behaviours were recorded using a 32-channel Electroencephalogram(EEG)and glasses-based eye tracker,with the observation and post-experiment questionnaires to evaluate the flight operations and pilots’*** alone,there was a significantly increased cortical activity in h and b waves over the frontal,parietal,and temporal lobes during the more complicated emergencies,and pilots focused less on the primary flight display while spending significantly more time scanning the other *** physiological fluctuating patterns associated with risky operations in SPO were highlighted by cross-correlating multimodal *** experimental-based noteworthy insights may wish to inform commercial SPO measures to lessen the persistent physiological fluctuation,assisting airlines in creating SPO-oriented intelligent flight systems to give captains adequate support for assuring safer air transportation.

关键词： Aviation engineering Single pilot operations Behaviour changes Eye tracker Electroencephalogram

On some new fuzzy entropy measure of Pythagorean fuzzy sets for decision-making based on an extended TOPSIS approach

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Journal of Management Analytics 2024年第1期11卷 87-109页

作者： h.d.Arora Anjali Naithani department of Mathematics Amity Institute of Applied SciencesAmity University Uttar PradeshNoidaIndia

Fuzzy entropy measures are valuable tools in decision-making when dealing with uncertain or imprecise *** exist many entropy measures for Pythagorean Fuzzy Sets(PFS)in the literature that fail to deal with the problem of providing reasonable or consistent results to the *** deal with the shortcomings of the existing measures,this paper proposes a robust fuzzy entropy measure for PFS to facilitate decision-making under *** usefulness of the measure is illustrated through an illustration of decision-making in a supplier selection problem and compared with existing fuzzy entropy *** Technique for Order Performance by Similarity to Ideal Solution(TOPSIS)approach is also explored to solve the decision-making *** results demonstrate that the proposed measure can effectively capture the degree of uncertainty in the decision-making process,leading to more accurate decision outcomes by providing a reliable and robust ranking of alternatives.

关键词： Pythagorean fuzzy sets entropy measures multi criteria decision analysis TOPSIS method supplier selection

Network Embedding Algorithm for Vulnerability Assessment of Power Transmission Lines Using Integrated Structure and Attribute Information

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 351-360页

作者： Xianglong Lian Tong Qian Zepeng Li Xingyu chen Wenhu Tang Q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China

In power systems,failures of vulnerable lines can trigger large-scale cascading failures,and vulnerability assessment is dedicated to locating these lines and reducing the risks of such *** on a structure and attribute network embedding(SANE)algorithm,a novel quantitative vulnerability analysis method is proposed to identify vulnerable lines in this ***,a two-layered random walk network with topological and electrical properties of transmission lines is ***,based on the weighted degree of nodes in the two-layered network,the inter-layer and intra-layer walking transition probabilities are developed to obtain walk ***,a Word2Vec algorithm is applied to obtain lowdimension vectors representing transmission lines,according to obtained walk sequences for calculating the vulnerability index of transmissions ***,the proposed method is compared with three widely used methods in two test *** show the network embedding based method is superior to those comparison methods and can provide guidance for identifying vulnerable lines.

关键词： Network embedding random walk transmission lines vulnerability assessment

The multi-impurity system in CdSe nanoplatelets:electronic structure and thermodynamic properties

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Communications in Theoretical Physics 2024年第3期76卷 165-173页

作者： d A Baghdasaryan V A harutynyan E M Kazaryan h A Sarkisyan Russian-Armenian University H Emin 1230051YerevanArmenia Institute of Applied Problems of Physics 25 Nersisyan St0014YerevanArmenia

This paper theoretically studies the impurity states and the effects of impurity concentration and configuration on the optical,electrical,and statistical properties of CdSe nanoplatelets(NPLs).An image charge-based model of electron-impurity interaction is *** charge-carrier energy spectra and corresponding wave functions depending on the impurity number and configuration are *** electron binding energies are calculated for different NPL *** is shown that the image charge-based interaction potential that arises due to the dielectric constants mismatch is much stronger than the interaction potential that does not take such a mismatch into ***,it is demonstrated that the binding energies are increasing with the number of *** calculate the canonical partition function using the energy levels of the electron,which in turn is used to obtain the mean energy,heat capacity,and entropy of the non-interacting electron *** thermodynamic properties of the non-interacting electron gas that depend on the geometric parameters of the NPL,impurity number,configuration,and temperature are studied.

关键词： nanoplateletes thermodynamic properties impurity states