检索结果-南通市图书馆

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

Design of compact integrated diamond nitrogen-vacancy center quantum probe

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第5期33卷 409-415页

作者：夏圣开卢文韬赵旭彤薛雅文许增博葛仕宇汪洋虞林嫣卞雨辰安思瀚杨博向建军杜关祥 School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Portland Institute Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Economics Nanjing University of Posts and TelecommunicationsNanjing 210023China Jiangsu Institute of Quality and Standardization Nanjing 210012China Chengdu Analog Circuit Technology Inc. Chengdu 201203China

An integrated quantum probe for magnetic field imaging is proposed,where the nitrogen–vacancy(NV)center fixed at the fiber tip is located on the periphery of flexible ring *** flexible polyimide(PI)as the substrate medium,we design a circular microstrip antenna,which can achieve a bandwidth of 140 MHz at Zeeman splitting frequency of 2.87 GHz,specifically suitable for NV center ***,this antenna is seamlessly fixed at a three-dimensional-printed cylindrical support,allowing the optical fiber tip to extend out of a dedicated *** mitigate errors originating from processing,precise tuning within a narrow range can be achieved by adjusting the conformal ***,we image the microwave magnetic field around the integrated probe with high resolution,and determine the suitable area for placing the fiber tip(SAP).

关键词： nitrogen-vacancy center conformal antenna integrated probe magnetic field imaging

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

在线全文

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

Micron-sized fiber diamond probe for quantum precision measurement of microwave magnetic field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第8期33卷 186-190页

作者：卢文韬夏圣开陈爱庆何康浩许增博陈艺涵汪洋葛仕宇安思瀚吴建飞马艺菡杜关祥 Portland Institute Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Telecommunication and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China School of Economics Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Electronic and Optical Engineering Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Electronic Science and Technology National University of Defense TechnologyChangsha 410000China

We present a quantitative measurement of the horizontal component of the microwave magnetic field of a coplanar waveguide using a quantum diamond probe in fiber *** measurement results are compared in detail with simulation,showing a good *** simulation shows fiber diamond probe brings negligible disturbance to the field under measurement compared to bulk *** method will find important applications ranging from electromagnetic compatibility test and failure analysis of high frequency and high complexity integrated circuits.

关键词： quantum precision measurement electromagnetic field diamond NV center quantum metrology

Forecasting the western Pacific subtropical high index during typhoon activity using a hybrid deep learning model

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2022年第4期41卷 101-108页

作者： Jianyin Zhou Mingyang Sun Jie xiang Jiping guan Huadong du Lei Zhou College of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhou 510275China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China

Seasonal location and intensity changes in the western Pacific subtropical high(WPSH)are important factors dominating the synoptic weather and the distribution and magnitude of precipitation in the rain belt over East ***,this article delves into the forecast of the western Pacific subtropical high index during typhoon activity by adopting a hybrid deep learning ***,the predictors,which are the inputs of the model,are analysed based on three characteristics:the first is the statistical discipline of the WPSH index anomalies corresponding to the three types of typhoon paths;the second is the correspondence of distributions between sea surface temperature,850 hPa zonal wind(u),meridional wind(v),and 500 hPa potential height field;and the third is the numerical sensitivity experiment,which reflects the evident impact of variations in the physical field around the typhoon to the WPSH ***,the model is repeatedly trained through the backward propagation algorithm to predict the WPSH index using 2011–2018 atmospheric variables as the input of the training *** model predicts the WPSH index after 6 h,24 h,48 h,and 72 *** validation set using independent data in 2019 is utilized to illustrate the ***,the model is improved by changing the CNN2D module to the DeCNN module to enhance its ability to predict *** the 2019 typhoon“Lekima”as an example,it shows the promising performance of this model to predict the 500 hPa potential height field.

关键词： WPSH index typhoon hybrid deep learning model predictors numerical sensitivity experiment

Reaction Mechanism,Synthesis and Characterization of Urea-glyoxal(UG) Resin

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2013年第12期32卷 1773-1786页

作者： DENG Shu-duan LI xiang-Hong XIE Xiao-guang du guan-Ben College of Materials Science and Technology Beijing Forestry University Yunnan Key Laboratory of Wood Adhesives and Glue Products Southwest Forestry University School of Chemical Science and Technology Yunnan University

The reaction mechanism of glyoxal （G） with urea （U） under weak acid condition was theoretically investigated at PW91/DNP/COSMO of quantum chemistry using density functional theory （DFT） method. The results show that the addition reaction of G with U under the conditions mainly involves the reactions of U with protonated glyoxal （p-G）, protonated 2,2-dihy- droxyacetaldehyde （p-G 1） and protonated bis-hemdiol （p-G2） to form two important carbocation reactive intermediates of C-p-UG and C-p-UG1, and two important hydroxyl compounds of UG and UG1. These compounds play important roles in the formation of UG resin. According to the result of quantum chemical calculation, UG resin was synthesized successfully under weak acid conditions. The UG resin was characterized by matrix assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）, ultraviolet and visible spectroscopy （UV-vis）, Fourier transform infrared spectroscopy （FT1R） and nuclear magnetic resonance spectroscopy （13CNMR and 1HNMR）. These instrumental analytical results agree with each other and further confirm the addition reaction pathway of glyoxal with urea proposed by quantum chemical calculation.

关键词： urea-glyoxal (UG) resin reaction mechanism,synthesis MALDI-TOF FTIR NMR UV-vis

Optimal constant in an L^2 extension problem and a proof of a conjecture of Ohsawa

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2015年第1期58卷 35-59页

作者： guan Qi'An ZHOU xiang Yu Beijing International Center for Mathematical Research Peking University School of Mathematical Sciences Peking University Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences Hua Loo-Keng Key Laboratory of Mathematics Chinese Academy of Sciences

In this paper,we solve the optimal constant problem in the setting of Ohsawa’s generalized L2extension *** applications,we prove a conjecture of Ohsawa and the extended Suita conjecture,we also establish some relatio... 详细信息

关键词： L2 extension theorem optimal L2 estimate Bergman kernel a conjecture of Ohsawa extendedSuita conjecture

Analysis of Vibrational Performance of A Piezoelectric Micropump with Diffuse/Nozzle Microchannel

在线全文

学校读者我要写书评

暂无评论

Nanotechnology and Precision Engineering 2018年第2期1卷 138-144页

作者： Yanfang guan xiang Li School of Mechanical and Electrical Engineering Henan University of TechnologyZhengzhou 450001China

Piezoelectric transducers of different external diameters are designed and fabricated and incorporated into micropumps. Through finite element analysis, it is shown that the volume efficiency of the micropump reaches its maximum value for the first mode of vibration. The variation of maximum displacement with frequency is determined under free and forced vibration. Results demonstrate that this variation shows the same trend for different driving waves at the same driving voltage. The maximum displacement under forced vibration is less than that under free vibration. The displacement increases with decreasing distance from the center of the transducer. The maximum displacement is inversely proportional to the diameter of the transducer and proportional to the driving voltage under both free and forced vibrations. Finally, the micropump flow rate and pressure are measured and are found to manifest the same trend as the maximum displacement under the same driving conditions. For a piezoelectric transducer of 12 mm external diameter, the maximum flow rate and pressure value are 150 μL/min and 346 Pa, respectively, under sine-wave driving at 100 Vpp driving voltage.

关键词： Micropump Vibrational displacement Piezoelectric transducer Microflow

Electrical modeling of dielectric barrier discharge considering surface charge on the plasma modified material

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第7期29卷 383-388页

作者： Hong-Lu guan xiang-Rong Chen Tie Jiang Hao du Ashish Paramane Hao Zhou Zhejiang Provincial Key Laboratory of Electrical Machine Systems College of Electrical EngineeringZhejiang UniversityHangzhou 310027China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou 311200China

We present the variations of electrical parameters of dielectric barrier discharge(DBD)when the DBD generator is used for the material modification,whereas the relevant physical mechanism is also *** equivalent circuit model is applied for a DBD generator working in a filament discharging mode,considering the addition of epoxy resin(EP)as the plasma modified *** electrical parameters are calculated through the circuit *** surface conductivity,surface potential decay,trap distributions and surface charge distributions on the EP surface before and after plasma treatments were measured and *** is found that the coverage area of micro-discharge channels on the EP surface is increased with the discharging time under the same applied AC *** results indicate that the plasma modified material could influence the ignition of new filaments in return during the modification ***,the surface conductivity and density of shallow traps with low trap energy of the EP samples increase after the plasma *** surface charge distributions indicate that the improved surface properties accelerate the movement and redistribution of charge carriers on the EP *** variable electrical parameters of discharge are attributed to the redistribution of deposited surface charge on the plasma modified EP sample surface.

关键词： dielectric barrier discharge surface charge plasma treatment circuit model