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物理学报 2002年第4期51卷 809-813页

作者：卞保民杨玲陈笑倪晓武南京理工大学应用物理系南京210094

根据激光等离子体空气冲击波在自由空间中传播的约束条件导出的空气冲击波前运动方程与点爆炸波泰勒解进行比较 ,证明泰勒解是该冲击波波前传播方程在中场的近似形式 .并将该冲击波运动方程与强爆炸空气冲击波的实验进行比较。

关键词：核爆炸泰勒解波前运动方程激光等离子体空气冲击波点爆炸

Multicolor circularly polarized phosphorescence of axially chiral binuclear platinum(Ⅱ) complexes

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science china Chemistry 2024年第11期67卷 3757-3766页

作者： Jintong Song Rui Zeng Hui xiao Hailiang Ni Zong-Xiang Xu Haifeng Xiang College of Chemistry and Materials science Sichuan Normal University Department of Chemistry Southern University of Science and Technology College of Chemistry Sichuan University

D-A charge transfer, including through-bond charge transfer and through-space charge transfer between two different electron donors（D） and electron acceptors（A）, is a fundamental and powerful tool to tune the optical properties of organic dyes. Herein,we demonstrate a unique strategy to tune phosphorescence and circularly polarized luminescence properties of axially chiral binuclear Pt（Ⅱ） complexes through long-range charge transfer, even though these molecules have two totally identical segments on either side of the chiral core. The presence of axial chirality would break not only the symmetry of molecular structure and π-conjugation system but also the symmetry of charge distribution for long-range charge transfer. These binaphthyl-based Pt（Ⅱ）complexes bearing coordinated atoms far away from chiral axis exhibit no Pt-Pt interactions but colorful concentrationdependent phosphorescence with quantum yield up to 86.4% and could be applied as emitters in highly efficient solutionprocessed organic light-emitting diodes to achieve luminance, luminance efficiency, power efficiency, external quantum efficiency, and asymmetry factor up to 8.94 × 10～3cd m-2, 41.9 cd A-1, 18.8 lm W-1, 12.6% and 2.98 × 10-3, respectively. Therefore,the present work affords a new and simple way to utilize the inherently asymmetric advantage of chirality for the design of D-Abased organic dyes.

关键词： Pt(II) complexes organic light-emitting diodes circularly polarized phosphorescence axial chirality

An Audio Zero-Watermark Scheme Based on Energy Comparing

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china Communications 2014年第7期11卷 110-116页

作者： YANG Yu LEI Min CHENG Mingzhi LIU Bohuai LIN Guoyuan xiao Da Information Security Center Beijing University of Posts and Telecommunications Beijing China College of Information Engineering Beijing Institute of Graphic Communication Beijing China National Engineering Laboratory for Disaster Backup and Recovery Beijing China school of Computer science and technology China University of Mining and Technology China

Zero-watermark technique,embedding watermark without modifying carriers,has been broadly applied for copyright protection of ***,there is little research on audio *** paper proposes an audio zero-watermark scheme based on energy relationship between adjacent audio *** use of discrete wavelet transformation(DWT),it gets power approximations,or energies,of audio ***,it extracts the audio profile,*** zero-watermark,according to the relative size of energies of consecutive *** experimental results demonstrate that the proposed scheme is robust against general malicious attacks including noise addition,resampling,low-pass filtering,etc.,and this approach effectively solves the contradiction between inaudibility and robustness.

关键词： zero-watermark audio water-marking scheme energy comparing

A Secure Cryptographic System Based on Steady-State Visual Evoked Potential Brain-Computer Interface technology

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Journal of Systems science and Information 2024年第3期12卷 423-432页

作者： Xu xiao Feiyang ZHANG Wenhan YIN Dezhi ZHENG College of Life and Environmental science Minzu University of ChinaBeijing 100081China school of Instrumentation and Optoelectronic Engineering Beihang UniversityBeijing 100191China Advanced Research Institute of Multidisciplinary sciences Beijing Institute of TechnologyBeijing 100081China

Addressing the vulnerability of contact-based keyboard password systems to disclosure,this paper proposes and validates the feasibility of a non-contact secure password system based on brain-computer interface(BCI)technology that detects steady-state visual evoked potential(SSVEP)*** system first lets a testee look at a digital stimulus source flashing at a specific frequency,and uses a wearable dry electrode sensor to collect the SSVEP ***,a canonical correlation analysis method is applied to analyze the frequency of the stimulus source that the testee is looking at,and feeds back a code result through ***,after all password codes are input,the system makes a judgment and provides visual feedback to the *** were conducted to test the accuracy of the system,where twelve stimulus target frequencies between 10-16Hz were selected within the easily recognizable flicker frequency range of human brain,and each of them was tested for 12 *** results demonstrate that this SSVEP-BCI-based system is feasible,achieving an average accuracy rate of 97.2%,and exhibits promising applications in various domains such as financial transactions and identity recognition.

关键词： brain computer interface steady-state visual evoked potential password system

Current transport in ZnO/Si heterostructure grown by laser molecular beam epitaxy

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Chinese Physics B 2012年第9期21卷 440-444页

作者：滕晓云吴艳华于威高卫傅广生 College of Physics science and technology University of Hebei University

The n-ZnO/p-Si heterojunction was fabricated by depositing high quality single crystalline aluminium-doped n-type ZnO film on p-type Si using the laser molecular beam epitaxy technique. The heterojunction exhibited a good rectifying behavior. The electrical properties of the heterojunction were investigated by means of temperature dependence current density-voltage measurements. The mechanism of the current transport was proposed based on the band structure of the heterojunction. When the applied bias V is lower than 0.15 V, the current follows the Ohmic behavior. When 0.15 V ~ V 〈 0.6 V, the transport property is dominated by diffusion or recombination in the junction space charge region, while at higher voltages （V 〉 0.6 V）, the space charge limited effect becomes the main transport mechanism. The current-voltage characteristic under illumination was also investigated. The photovoltage and the short circuit current density of the heterojunction aproached 270 mV and 2.10 mA/cm^2, respectively.

关键词： ZnO/Si heterostructure current transport laser molecular beam epitaxy

Studies on Electrophilic Substitution of Quasi-Aromatic Metal Ion Complexes

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Chemical Research in Chinese Universities 1993年第4期9卷 282-287页

作者： XIA xiao-ping, HE Hai-ying and LI Ming (Department of Chemistry, Huazhong university of science and technology, Wuhan, 430074)ZHAO Cheng-xue (National Laborotory of applied Organic Chemistry, Lanzhou university, Lanzhou, 730000)

The electrophilic substitution reaction occurring to the chelate ring of the complexes could be regarded as an indication of quasi-aromaticity of the ring systems, no catalyst was used and only triethylamine was employed, implying that the aroylating agents with different p-substituents are polarized enough to be effective electrophiles to attack the methine carbon of the electron-rich substrate 1. This property is probably the clue to polarization of the ligand electrons by the nickel( Ⅱ ) ion and to the participation of the nickel( Ⅱ ) in the π-bond systems of the two coordinated conjugated rings. The linearity relationship between vd-d maxima, E1/2OX(1) and σp are obtained, respectively. The electronic environment of central metal ion as well as the aromaticity of the ring system are affected by the electronic properties of the p-substituents. A comparison of the electrochemical results with each other showed .that when the electronegativity of the substituent was higher, the oxidation(Ni2+/Ni3+) becomes more difficult.

关键词： Electrophilic substitution Quasi-aromatic metal ions Complex

Lowering Sodium-Storage Lattice Strains of Layered Oxide Cathodes by Pushing Charge Transfer on Anions

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Energy & Environmental Materials 2024年第4期7卷 99-106页

作者： Na Li Wen Yin Baotian Wang Fangwei Wang xiaoling xiao Jinkui Zhao Enyue Zhao Songshan Lake Materials Laboratory beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Spallation Neutron Source science Center Institute of High Energy Physics Chinese Academy of Sciences College of Materials science and Opto-electronic technology Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Due to a high energy density,layered transition-metal oxides have gained much attention as the promising sodium-ion batteries ***,they readily suffer from multiple phase transitions during the Na extraction process,re... 详细信息

关键词： anionic redox reaction lattice strains layered oxide cathodes phase transitions sodium-ion battery

An electromagnetic semi-active dynamic vibration absorber for thin-walled workpiece vibration suppression in mirror milling

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applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1315-1334页

作者： Jianghua KONG Bei DING Wei WANG Zhixia WANG Juliang xiao Hongyun QIU school of Mechanical Engineering Tianjin UniversityTianjin 300350China Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin 300350China Key Laboratory of Modern Mechanisms and Equipment Design of the State Ministry of Education Tianjin UniversityTianjin 300350China

As critical components of aircraft skins and rocket fuel storage tank shells,large thin-walled workpieces are susceptible to vibration and deformation during machining due to their weak local *** address these challenges,we propose a novel tunable electromagnetic semi-active dynamic vibration absorber(ESADVA),which integrates with a magnetic suction follower to form a followed ESADVA(follow-ESADVA)for mirror *** system combines a tunable magnet oscillator with a follower,enabling real-time vibration absorption and condition feedback throughout the milling ***,the device supports self-sensing and frequency adjustment by providing feedback to a linear actuator,which alters the distance between *** resolves the traditional issue of being unable to directly monitor vibration at the machining point due to space constraints and tool *** frequency shift characteristics and vibration absorption performance are comprehensively *** and experimental results demonstrate that the prototyped follow-ESADVA achieves frequency synchronization with the milling tool,resulting in a vibration suppression rate of approximately 47.57%.Moreover,the roughness of the machined surface decreases by18.95%,significantly enhancing the surface *** results of this work pave the way for higher-quality machined surfaces and a more stable mirror milling process.

关键词： semi-active dynamic vibration absorber(SADVA) mirror milling selfsensing vibration absorption tuning thin-walled workpiece

Syntheses of new di-nuclear and tetra-nuclear lanthanide 9-anthracenecarboxylates:Magnetocaloric effect,slow magnetic relaxation and luminescent properties

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Journal of Rare Earths 2024年第6期42卷 1101-1109,I0004页

作者： Xing Liu Ruonan Yang Lu Zhang Jian Zhou Chunmei Huang Huahong Zou Zunhong xiao Chongqing Key Laboratory of Inorganic Functional Materials College of ChemistryChongqing Normal UniversityChongqing401331China Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of china) School of Chemistry and Chemical Engineering of Guangxi Normal UniversityGuilin541004China school of Chemistry and Materials Guizhou Normal UniversityGuiyang550025China

Lanthanide complex-based materials with magnetic and luminescent properties have received a great deal of attention,owing to their importantly potential applications in diverse *** this work,the 9-anthracenecarboxylic acid(9-Haca)as bridging ligand was applied in combination with optically activeπ-conjugated 2,4,6-tri(2-pyridyl)-1,3,5-triazine(tptz)to construct a series of new di-nuclear and tetranuclear lanthanide 9-anthracenecarboxylates[La_(2)(9-aca)_(6)(tptz)_(2)(μ-H_(2)O)]·0.25H_(2)O(1),[Ln_(2)(9-aca)_(6)(tptz)_(2)(H_(2)O)_(2)]·0.5AQ·CH_(3)COOH_(2)H_(2)O[Ln=Sm(2a),Eu(2b),Gd(2c),Tb(2d),Dy(2e),Tm(2f);AQ=9,10-anthracenedione]and[Ln_(4)(9-aca)_(10)(tptz)_(2)(CH3COO)2]·H_(2)O[Ln=Eu(3a),Gd(3b),Dy(3c)].1 displays a di-nuclear centrosymmetric moiety[La_(2)(9-aca)_(6)(tptz)_(2)(μ-H_(2)O)]built up from two complex[La(9-aca)_(2)(tptz)]groups bridged by one H_(2)O molecule and two syn-syn-μ2-η1:η1-9-aca-bridging ligands,while 2a-2f are isostructural and co mprise another di-nuclear centrosymmetric moieties[Ln_(2)(9-aca)_(6)(tptz)_(2)(H_(2)O)_(2)]based on two complex[Ln(9-aca)_(2)(tptz)(H_(2)O)]groups connected by two syn-syn-μ2-η1:η1-9-aca-bridging ligands,3a-3c are isostructural and show tetra-nuclear centro symmetric moieties[Ln4(9-aca)10(tptz)2(CH3COO)2]containing three types of coordination modes of *** present compounds offer the only examples of lanthanide 9-anthracenecarboxylates decorated by optically active *** investigations of 2a,2c-2f,and 3b-3c indicate that 3c is typical of slow relaxation of the magnetization,while 2c and 3b show significant magnetocaloric effect(MCE)with the value of-ΔSm of 5.26 J/(kg·K)at 4 K and 15.65 J/(kg·K)at 2 K(ΔH=7 T),*** luminescent properties were also studied and reveal that the characteristic luminescent properties of the 7r-conjugated aromatic ligands are introduced into magnetic lanthanide 9-anthracenecarboxylates,simultaneously exhibiting slow magnetic relaxation(or MCE)and luminescen

关键词： Lanthanide complexes Luminescence Magnetic properties Magnetocaloric effect Slow magnetic relaxation Rare earths

Wireless electrical stimulation generated by piezoelectric nanomaterial promotes the dental pulp regeneration via regulating mitochondrial Ca^(2+)/PKA signaling pathway

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Journal of Materials science & technology 2024年第1期168卷 24-34页

作者： Jianmao Zheng Jiyuan Zuo Cairong xiao Qining Guo xiaobin Fu Chengyun Ning Peng Yu Guangdong Provincial Key Laboratory of Stomatology Hospital of StomatologySun Yat-Sen UniversityGuangzhou 510080China school of Materials science and Engineering National Engineering Research Center for Tissue Restoration and ReconstructionSouth China University of TechnologyGuangzhou 510641China

The induction of dental pulp stem cells(DPSCs)into odontogenic differentiation is a cutting-edge method of dental pulp regeneration ***,it remains a challenge to develop biomaterials and ther-apies that can induce odontogenic ***,we propose a wireless electrical stimulation strat-egy to induce DPSCs odontogenic differentiation via K_(0.5)Na_(0.5)NbO_(3)piezoelectric nanoparticles(KNN)and polarized KNN(PKNN),which can be endocytosed by *** vitro,several odontogenic differentiation indexes were also increased in DPSCs treated with KNN and PKNN,and the increase was more obvious in the PKNN *** wireless electrical field promoted mitochondrial calcium concentration via mitochondrial calcium unidirectional transporter(MCU),increased the production of adenosine triphos-phate(ATP),and induced odontogenic differentiation through the activation of the cAMP-PKA signaling *** vivo,dental pulp-like tissue was induced by electrical stimulation wirelessly with KNN and PKNN,which was more clinically friendly compared with the wired device,and the induction was more obvious in the PKNN group consistent with in vitro *** conclusion,this work demonstrates the potential of PKNN as an effective stimulus that can induce odontogenic differentiation of DPSCs and be applied to dental pulp regeneration treatment.

关键词： Piezoelectric nanoparticles Dental pulp stem cells Odontogenic differentiation