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Theoretical studies on alloying of germanene supported on Al (111) substrate

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Chinese Physics B 2020年第10期29卷 521-534页

作者： Qian-Xing Chen hao Yang gang Chen Laboratory of Advanced Materials Physics and Nanodevices School of Physics and TechnologyUniversity of JinanJinan 250022China School of Physics and Electronics Shandong Normal UniversityJinan 250358China

Using density functional theory,we study the alloying of the buckled hexagonal germanene superlattice supported on Al(111)-(3×3),the sheet composed of triangular,rhombic,and pentagonal motifs on Al(111)-(3×3),and the buckled geometry on Al(111)-(√7×√7)(19°),which are denoted,respectively,by BHS,TRP,and SRT7,to facilitate the discussion in this *** could be alloyed in the low doping concentration *** stable configurations BHS,TRP,and SRT7 of the pure and alloyed germanenes supported on both Al(111) and its Al2 Ge surface alloy,except the SRT7 pure germanene on Al2 Ge,could re-produce the experimental scanning tunneling microscopy *** relatively stable AlGe alloy species are the Al3 Ge5 BHS-2 T,Al3 Ge5 TRP-2 T,and Al3 Ge3 SRT7-1 T on Al(111) while they are the Al4 Ge4 BHS-1 T,Al3 Ge5 TRP-2 T,and A127 Ge27 SRT7-(3×3)-9 T on Al2 Ge(the n in the nT means that there are n Ge atoms per unit which sit at the top sites and protrude upward).In addition,the Al3 Ge5 BHS-2 T and Al4 Ge4 BHS-1 T are the most stable alloy sheets on Al(111) and Al2 Ge,*** with the experimental studies,there exists no structural transition among these alloyed configurations,which suggests that the experimental conditions play a crucial role in selectively growing the pure or the alloyed germanene sheets,which may also help grow the one-atomic thick honeycomb structure on idea Al(111).

关键词： first-principles calculation alloyed two-dimensional material substrate for two-dimensional material growth two-dimensional nanostructure

Fabrication and characterization of superconducting RSFQ circuits

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Rare Metals 2019年第10期38卷 899-904页

作者： gang Li hao Li Jian-She Liu Wei Chen Tsinghua National Laboratory for Information Science and Technology Institute of MicroelectronicsDepartment of Microelectronics and NanoelectronicsTsinghua University

To meet the specification of the qubits in our laboratory,a 0.4 kA·cm^-2 superconducting rapid single flux quantum(RSFQ) circuit was designed and successfully fabricated with an improved Nb-based self-aligned lift-off *** circuit consists of a single-fluxquantum(SFQ) pulse generator,a Josephson transmission line(JTL) and a T-flip flop(TFF),and it acts as a frequency *** values of the inductors in this circuit were extracted using InductEX and the basic function of this circuit was confirmed using the simulation software WRspice before *** fabrication,the basic parameters of this circuit were measured at ~2.5 K in a Janis He-3 *** work laid the theoretical and experimental basis for the future research on the RSFQqubit control circuits.

关键词： Rapid single flux quantum Frequency divider WRspice InductEX

Proton radioactivity within the generalized liquid drop model with various versions of proximity potentials

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Communications in Theoretical Physics 2021年第6期73卷 102-109页

作者： Yu-Qi Xin Jun-gang deng Hong-Fei Zhang School of Nuclear Science and Technology Lanzhou University730000 LanzhouChina

In the present work,we systematically investigate the proton radioactivity half-lives of spherical proton emitters adopting a generalized liquid drop model(GLDM)with 16 different proximity potentials,of which the proximity potential Prox.77-13 gives the closest results to the experimental *** with the previous conclusion that the GLDM with proximity potential Prox.77-13 can also best describeαdecay half-lives,which makes the model more uniform and ***,we use the proximity potential Prox.77-13 in GLDM to predict the proton radioactivity half-lives of 14 spherical proton emitters that are allowed energetically but not yet observed experimentally or specifically ***,we research the Geiger-Nuttall law for proton *** results reveal that the Geiger-Nuttall law can also be well used to study the proton radioactivity half-lives of isotopes with the same orbital angular momentum l.

关键词： spherical proton emitter GLDM proximity energy Geiger-Nuttall law

Ecosystem Health: Assessment Framework, Spatial Evolution, and Regional Optimization in Southwest China

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Chinese Geographical Science 2020年第1期30卷 142-156页

作者： ZHANG hao SUN Jian deng Wei PENG Li Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China School of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China College of Geography and Resources Sichuan Normal UniversityChengdu 610101China

Regional ecological health,the core of comprehensive ecosystem assessments,is an important foundation for regional exploration,environmental conservation,and sustainable *** mountainous areas in southwest China are backward in economy,but industrialization and urbanization have been rapid in recent *** study assessed the ecosystem health of the Sichuan and Yunnan provinces in China using a pressure-state-response(PSR)*** patterns of regional ecosystem health were analyzed from 2000 to 2016,including overall characteristics as well as local *** health in most regions was improved over time(Y=0.0058 X–11.0132,R2=0.95,P0.05).Overall,the regional ecosystems to the east of the Hu line-an imaginary line dividing east and west China into roughly equivalent parts-were healthier than those to the *** pressure and state scores of ecosystems were determined by physiographic condition,and the response scores by government policies and social *** spatiotemporal patterns of ecosystem health were dominated to a greater extent by natural than anthropogenic factors,which explains why the shift in the patterns aligned with the direction of the Hu *** regions into key management areas based on natural geographical conditions and socioeconomic development could contribute to the formulation of a reasonable ecological and environmental protection policy,guaranteeing ecosystem services in the long run.

关键词： ecosystem health spatiotemporal pattern pressure-state-response(PSR) standard deviational ellipse mountain area

Uncertain Multidisciplinary Design Optimization on Next Generation Subsea Production System by Using Surrogate Model and Interval Method

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China Ocean Engineering 2021年第4期35卷 609-621页

作者： WU Jia-hao ZHEN Xing-wei LIU gang HUANG Yi School of Naval Architecture and Ocean Engineering Dalian University of TechnologyDalian 116024China

The innovative Next Generation Subsea Production System(NextGen SPS)concept is a newly proposed petroleum development solution in ultra-deep water *** definition of NextGen SPS involves several disciplines,which makes the design process *** this paper,the definition of NextGen SPS is modeled as an uncertain multidisciplinary design optimization(MDO)*** deterministic optimization model is formulated,and three concerning disciplines—cost calculation,hydrodynamic analysis and global performance analysis are *** model technique is applied in the latter two *** optimization(CO)architecture is utilized to organize the concerning disciplines.A deterministic CO framework with two disciplinelevel optimizations is proposed *** the uncertainties of design parameters and surrogate models are incorporated by using interval method,and uncertain CO frameworks with triple loop and double loop optimization structure are established *** optimization results illustrate that,although the deterministic MDO result achieves higher reduction in objective function than the uncertain MDO result,the latter is more reliable than the former.

关键词： next generation subsea production system multidisciplinary design optimization uncertain optimization collaborative optimization surrogate model interval method

Dynamic State Estimation of Medium-voltage DC Integrated Power System with Pulse Load

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Journal of Modern Power Systems and Clean Energy 2020年第4期8卷 689-698页

作者： Runlong Xiao gang Wang Xiaoliang hao Renji Huang Youxing Xiong National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of EngineeringWuhan 430033China

The dynamic characteristic evaluation is an important prerequisite for safe and reliable operation of the mediumvoltage DC integrated power system(MIPS),and the dynamic state estimation is an essential technical approach to the *** the electromechanical transient process in a traditional power system,periodic change in pulse load of the MIPS is an electromagnetic transient *** the system state suddenly changes in the range of a smaller time constant,it is difficult to estimate the dynamic state due to periodic *** paper presents a dynamic mathematical model of the MIPS according to the network structure and control strategy,thereby overcoming the restrictions of algebraic variables on the estimation and developing a dynamic state estimation method based on the extended Kalman *** the method of adding fictitious process noise,it is possible to solve the problem that the linearized algorithm of the MIPS model is less reliable when an abrupt change occurs in the pulse ***,the accuracy of the dynamic state estimation and the stability of the filter can be improved under the periodic disturbance of pulse *** simulation and experimental results confirm that the proposed model and method are feasible and effective.

关键词： Medium-voltage DC integrated power system pulse load dynamic state estimation extended Kalman filter fictitious process noise

Indoor localization via l^1-graph regularized semi-supervised manifold learning

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The Journal of China Universities of Posts and Telecommunications 2012年第5期19卷 39-44,91页

作者： ZHU Yu-jia deng Zhong-liang JI hao School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing 100876 China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this paper, a new -graph regularized semi-supervised manifold learning （LRSML） method is proposed for indoor localization. Due to noise corruption and non-linearity of received signal strength （RSS）, traditional approaches always fail to deliver accurate positioning results. The -graph is constructed by sparse representation of each sample with respect to remaining samples. Noise factor is considered in the construction process of -graph, leading to more robustness compared to traditional k-nearest-neighbor graph （KNN-graph）. The KNN-graph construction is supervised, while the -graph is assumed to be unsupervised without harnessing any data label information and uncovers the underlying sparse relationship of each data. Combining KNN-graph and -graph, both labeled and unlabeled information are utilized, so the LRSML method has the potential to convey more discriminative information compared to conventional methods. To overcome the non-linearity of RSS, kernel-based manifold learning method （K-LRSML） is employed through mapping the original signal data to a higher dimension Hilbert space. The efficiency and superiority of LRSML over current state of art methods are verified with extensive experiments on real data.

关键词： -graph indoor positioning semi-supervised manifold learning wireless local area network (WLAN)

Bio-inspired Filter Design Based on Vortex Control Mechanism of Parallel Groove Structure

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Journal of Bionic Engineering 2023年第1期20卷 338-348页

作者： Yawei Zhu Dean Hu Yonggang Guo hao Ding gang Yang School of Mechanical and Electrical Engineering Henan University of TechnologyZhengzhou450001China Key Laboratory of Advanced Design and Simulation Techniques for Special Equipments Ministry of EducationHunan UniversityChangsha410082China

Solid–liquid separation is widely used in daily life and practical *** industrial filters are prone to clogging,but this rarely occurs in filter-feeding *** by the filter feeding mechanism of balaenid whales and considering the local grooves in the fringes layer,a new bionic filter is produced by 3D printing technology through the bionic design of the parallel channels inside the mouth of balaenid *** the same time,a test platform composed of the bionic filter,peristaltic pump,fluid pulse rectifier and water tank is built to carry out the fluid flow pattern dyeing and particle filtration *** is found that fluid separation occurs near the groove structure and local vortices are *** vortex control filtration mechanism makes the particles in the front grooves tend to accumulate on the left side,which has a certain anti-clogging ***,the increase of flow velocity leads to the enhancement of vortices,which makes the accumulation effect on the left more *** study initially practices the bionic application from biological model to engineering design,and the vortex control anti-clogging filtration mechanism proposed in the study has a wide range of application prospects and values.

关键词： Solid-liquid separation Balaenid whales Filter feeding-Bionic design Anti-clogging filtration mechanism

Elaboration of phosphoramidite ligands enabling palladium-catalyzed diastereo-and enantioselective all carbon [4+3]cycloaddition

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Science China Chemistry 2020年第7期63卷 911-916页

作者： Xing Zheng hao Sun Wu-Lin Yang Wei-Ping deng Shanghai Key Laboratory of New Drug Design School of PharmacyEast China University of Science and TechnologyShanghai 200237China

A palladium-catalyzed diastereo-and enantioselective all carbon [4+3] cycloaddition of trimethylenemethane was developed by employing the elaborate tetrahydroquinoline-derived phosphoramidite ligand. The exclusive regioselectivity was realized by using the aromatization-driven diene indole-2,3-quinodimethanes, affording biologically important cyclohepta[b]indoles with excellent diastereo-, and enantioselectivities(up to >20:1 dr, >99% ee). Furthermore, the more challenging pyrrolidone-3,4-dienes, in the absence of aromatization force, were also compatible inthereaction, providing novel cyclohepta[c]pyrrol-1(2H)-ones with excellent regio-, diastereo-, and enantioselectivities(up to >20:1 rr, >20:1 dr, >99% ee).

关键词： asymmetric catalysis |4+3|cycloaddition electron-deficient dienes palladium