检索结果-南通市图书馆

Structural distortions and magnetisms in Fe-doped LaMn1-x Fex O3（0 郑龙吴小山 Laboratory of Solid State Microstructures and Department of Physics,nanjing university

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第10期 567-570页

作者：郑龙吴小山 Laboratory of Solid State Microstructures and Department of Physics Nanjing University

X-ray absorption spectra(XAS) at Mn K-edge and Fe K-edge in LaMn1-x Fe x O3show that with the increase of Fe substitution the chemical valence of Mn4+decreases,while the chemical valence of Fe3+remains *** distortions,such as the rotating and tilting for oxygen octahedron in the unit cell vary with iron content.A phase transition occurs at the Fe content values of 0.2～*** evolutions of rotation and tilting angle of FeO6/MnO6octahedral may be the vital factors to the structure and *** believe that the spin configuration of Fe3+may vary from the intermediate spin t42g e1g(S = 3/2) to the higher spin t32g e2g(S = 5/2) near the phase transition.

关键词： structural distortion X-ray absorption phase transition

A Tilt-correction Adaptive Optical System for the Solar Telescope of nanjing university

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2003年第6期3卷 576-586页

作者： Chang-HuiRao Wen-HanJiang ChengFang NingLing Wei-ChaoZhou Ming-DeDing Xue-JunZhang Dong-HongChen meiLi Xiu-FaGao TianMi AdaptiveOpticsLab. InstituteofOpticsandElectronicsChineseAcademyoi~clencesP.O.Box350Chengdu610209 AstronomyDepartment NanjingUniversityNanjing210093

A tilt-correction adaptive optical system installed on the 430 mm Solar Telescope of nanjing university has been put in operation. It consists of a tip-tilt mirror, a correlation tracker and an imaging CCD camera. An absolute difference algorithm is used for detecting image motion in the correlation tracker. The sampling frequency of the system is 419 Hz. We give a description of the system's configuration, an analysis of its performance and a report of our observational results. A residual jitter of 0.14 arcsec has been achieved. The error rejection bandwidth of the system can be adjusted in the range 5-28 Hz according to the beacon size and the strength of atmospheric turbulence.

关键词： telescopes - atmospheric effects - instrumentation - adaptive optics - Sun: atmospheric motions

Transactions of nanjing university of Aeronautics & Astronautics Information for Contributors

在线全文

学校读者我要写书评

暂无评论

Transactions of nanjing university of Aeronautics and Astronautics 2018年第4期35卷 739-743页

作者： Zhu Jiajia Hao Xiaodong Wang Jie Guo Hongshuai Dou Hui Zhang Xiaogang Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies College of Material Science and Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China

Transactions of nanjing university of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic *** prompt and effective dissemination of key data and new scientific insights,TNUAA offers publication of new experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.

关键词： Astronautics Information for Contributors Transactions of nanjing university of Aeronautics

Practise of humanistic management, explore service innovation-We take the office work of nanjing forestry university south academy as an example

在线全文

学校读者我要写书评

暂无评论

International English Education Research 2016年第2期 30-32页

作者： WANG Siyu ZHOU Lin GUO Yanhui ZHOU Xiaojuan nanjing forestry university south academy

Graph neural network-based scheduling for multi-UAV-enabled communications in D2D networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第1期10卷 45-52页

作者： Pei Li Lingyi Wang Wei Wu Fuhui Zhou Baoyun Wang Qihui Wu nanjing university of Posts and Telecommunications Nanjing210023China nanjing university of Aeronautics and Astronautics Nanjing210016China

In this paper,we jointly design the power control and position dispatch for Multi-Unmanned Aerial Vehicle(UAV)-enabled communication in Device-to-Device(D2D)*** objective is to maximize the total transmission rate of Downlink Users(DUs).Meanwhile,the Quality of Service(QoS)of all D2D users must be *** comprehensively considered the interference among D2D communications and downlink *** original problem is strongly non-convex,which requires high computational complexity for traditional optimization *** to make matters worse,the results are not necessarily globally *** this paper,we propose a novel Graph Neural Networks(GNN)based approach that can map the considered system into a specific graph structure and achieve the optimal solution in a low complexity ***,we first construct a GNN-based model for the proposed network,in which the transmission links and interference links are formulated as vertexes and edges,***,by taking the channel state information and the coordinates of ground users as the inputs,as well as the location of UAVs and the transmission power of all transmitters as outputs,we obtain the mapping from inputs to outputs through training the parameters of *** results verified that the way to maximize the total transmission rate of DUs can be extracted effectively via the training on ***,it also shows that the performance of proposed GNN-based method is better than that of traditional means.

关键词： Unmanned aerial vehicle D2 Dcommunication Graph neural network Power control Position planning

Design of tightly linked dual ring antenna and imaging of magnetic field distribution using a diamond fiber probe

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 347-352页

作者：叶青云薛雅文何飞越赵旭彤卞雨辰卢文韬王金旭陈鸿浩夏圣开曾明菁杜关祥 College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Bell Honors School Nanjing University of Posts and TelecommunicationsNanjing 210023China

A tightly linked dual ring antenna is designed,and it is specifically tailored for uniformly coupling the microwave magnetic field to the nitrogen-vacancy(NV)*** designed antenna operates at a center frequency of about 2.87 GHz,with a bandwidth of around 200 MHz,allowing it to address multiple resonance peaks in the optically detected magnetic resonance(ODMR)spectrum in an external magnetic ***,the antenna generates a fairly uniform magnetic field in a range with a radius of 0.75 *** resolution imaging of the magnetic field distribution on the surface of the antenna is conducted by using a fiber diamond *** also investigate the effect of magnetic field uniformity on the linewidth of ODMR,so as to provide insights into reducing the inhomogeneous broadening of ODMR.

关键词： nitrogen vacancy(NV) microwave(MW)imaging inhomogeneous broadening

High-resolution imaging of magnetic fields of banknote anti-counterfeiting strip using fiber diamond probe

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 720-727页

作者：赵旭彤何飞越薛雅文马文豪殷筱晗夏圣开曾明菁杜关祥 College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Bell Honors School Nanjing University of Posts and TelecommunicationsNanjing 210023China

Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive *** such measure is the magnetic anti-counterfeiting ***,due to its inherent weak magnetic properties,visualizing its magnetic distribution has been a longstanding *** this work,we introduce an innovative method by using a fiber optic diamond probe,a highly sensitive quantum sensor designed specifically for detecting extremely weak magnetic *** employ this probe to achieve high-resolution imaging of the magnetic fields associated with the RMB 50denomination anti-counterfeiting ***,we conduct computer simulations by using COMSOL Multiphysics software to deduce the potential geometric characteristics and material composition of the magnetic region within the anti-counterfeiting *** findings and method presented in this study hold broader significance,extending the RMB 50 denomination to various denominations of the Chinese currency and other items that employ magnetic anti-counterfeiting *** advances have the potential to significantly improve and promote security measures in order to prevent the banknotes from being counterfeited.

关键词： banknote anti-counterfeiting strip nitrogen-vacancy(NV)centers magnetic field imaging numerical simulation

Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 55-66页

作者： Zhiyuan Zhang Hanyu Deng Wenhe Liao Bin Yu Zai Yu nanjing university of Science and Technology Nanjing 210094China

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano ***,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical *** conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition *** this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was *** detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were *** ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition *** results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition ***,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of *** the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,*** rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition *** to direct injection scheme,swirlin

关键词： Micro/nano satellite hybrid propulsion Arc ignition Charring conductive polymer Ignition mechanism Ignition characteristic Repeated ignition

Elevated CO_(2) increases soil redox potential by promoting root radial oxygen loss in paddy field

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 11-20页

作者： Jie Li Han Zhang Wenyi Xie Cheng Liu Xiaoyu Liu Xuhui Zhang Lianqing Li Genxing Pan Institute of Resource Ecosystem and Environment of AgricultureNanjing Agricultural UniversityNanjing 210095China College of Agriculture Nanjing Agricultural UniversityNanjing 210095China

Soil redox potential(Eh)plays an important role in the biogeochemical cycling of soil *** its effect soil process and nutrients'availability under elevated atmospheric CO_(2) concentration and warming has seldom been ***,in this study,a field experiment was used to elucidate the effect of elevated CO_(2) concentration and warming on soil Eh,redox-sensitive elements and root radial oxygen loss(ROL).We hypothesized elevated CO_(2) and warming could alter soil Eh by promoting or inhibiting *** found that soil Eh in the rhizosphere was significantly higher than that of *** CO_(2) enhanced soil Eh by 11.5%,which corresponded to a significant decrease in soil Fe^(2+)and Mn^(2+)*** elevated CO_(2),the concentration of Fe^(2+)and Mn^(2+)decreased by 14.7%and 13.7%,*** also found that elevated CO_(2) altered rice root aerenchyma structure and promoted rice root *** elevated CO_(2),rice root ROL increased by 79.5%and 112.2%for Yangdao 6 and Changyou 5,*** had no effect on soil Eh and rice root *** warming increased the concentration of Mn^(2+)and SO_(4)^(2-)by 4.9%and 19.3%,*** was a significant interaction between elevated CO_(2) and warming on Fe^(2+)and Mn^(2+).Under elevated CO_(2),warming had no effect on the concentration of Fe^(2+)but decreased Mn^(2+)concentration *** study demonstrated that elevated atmospheric CO_(2) in the future could increase soil Eh by promoting rice root ROL,which will alter some soil nutrients'availability,such as Fe^(2+)and Mn^(2+).

关键词： Atmospheric CO_(2)enrichment Global warming Soil redox potential FACE Rice root aerenchyma