科研成果

2015

Qi X, Wang T, Long Y, Ni J. Synergetic antibacterial activity of reduced graphene oxide and boron doped diamond anode in three dimensional electrochemical oxidation system. Scientific Reports. 2015;5.

Li CZ, Zhu R, Ke XX, Zhang JM, Wang LX, Zhang L, Liao ZM, Yu DP. Synthesis and Photovoltaic Properties of Cd3As2 Faceted Nanoplates and Nano-Octahedrons. Crystal Growth & DesignCrystal Growth & Design. 2015;15:3264-3270.Abstract

Recent theoretical predictions and angle-resolved photoemission spectroscopy measurements have shown that single crystal Cd3As2 is a three-dimensional topological Dirac semimetal possessing linear dispersions along all three momentum directions. Nanoscale topological Dirac semimetal structures have a large surface-to-volume ratio and provide a platform to explore its topological surface states. Here we report the synthesis of high quality Cd3As2 single crystalline nanoplates and nano-octahedrons via a vaporsolid growth mechanism. Triangular and hexagonal nanoplates with lateral dimensions ranging from several hundred nanometers to tens of micrometers are obtained. The top facets are (112), consistent with the natural cleavage plane of Cd3As2 single crystal. The synthesized Cd3As2 nano-octahedrons are enclosed by the {112} facets. A photovoltaic effect is demonstrated from a Cd3As2 nanoplate/metal electrode interface, suggesting potential applications in self-powered photodetection.

Tan S, Ma S, Wang S, Gao W. Synthesized Views Distortion Model Based Rate Control in 3D-HEVC, in Advances in Multimedia Information Processing - PCM 2015 - 16th Pacific-Rim Conference on Multimedia, Gwangju, South Korea, September 16-18, 2015, Proceedings, Part II.; 2015:24–32. 访问链接

Huang YT; MQ; T. TASC: A Transformation-Aware Soft Cascading Approach for Multimodal Video Copy Detection. ACM Transactions on Information Systems. 2015;33(2):Article 7-34 pages.

Yang S, Feng Y, Zou L, Jia A, Zhao D. Taxonomy Induction and Taxonomy-based Recommendations for Online Courses, in Proceedings of the 15th ACM/IEEE-CE on Joint Conference on Digital Libraries, Knoxville, TN, USA, June 21-25, 2015.; 2015:267–268.

岳聪, 汪群慧, 袁丽, 刘阳生*. TCLP 法评价铅锌尾矿库土壤重金属污染: 浸提剂的选择及其与重金属形态的关系. 北京大学学报(自然科学版). 2015;51(1):109 – 115.

Shi GL, Zhou XY, Feng YC*, Tian YZ, Liu GR, Zheng M*, Zhou Y, Zhang Y. Technical note: An improved estimate of uncertainty for source contribution from effective variance Chemical Mass Balance (EV-CMB) analysis. Atmospheric Environment [Internet]. 2015;100:154 - 158. LINK

Cheng Z, Liu L, Xu S, Lu M, Wang X. Temperature dependence of electrical and thermal conduction in single silver nanowire. Scientific reports. 2015;5(1):1-12.

Cheng Z, Liu L, Xu S, Lu M, Wang X. Temperature dependence of electrical and thermal conduction in single silver nanowire. Scientific reports. 2015;5:10718.

Yu R, Wang X, Wu W, Pan C, Bando Y, Fukata N, Hu Y, Peng W, Ding Y, Wang ZL*. Temperature dependence of the piezophototronic effect in CdS nanowires. Advanced Functional Materials. 2015;25:5277–5284.

Zhang C, Wang M, Xie B, Wen CP, Wang J, Hao Y, Wu W, Chen KJ, Shen B. Temperature Dependence of the Surface- and Buffer-Induced Current Collapse in GaN High-Electron Mobility Transistors on Si Substrate. IEEE TRANSACTIONS ON ELECTRON DEVICES. 2015;62:2475-2480.Abstract

The temperature dependence of current collapse (CC) in AlGaN/GaN high-electron mobility transistors on silicon substrate is studied in this paper. Devices without and with Si3N4 passivation are used to investigate the behavior of surface- and buffer-induced CC, respectively. It is found that the degree of surface-induced CC in unpassivated devices has a weak temperature dependence, which is induced by the cancelling out between enhanced carrier injection based on surface hopping and enhanced emission when the temperature is increased. On the other hand, the degree of buffer-induced CC in the Si3N4 passivated devices is reduced at higher temperature since the energy of hot electrons is reduced due to the phonon scattering and the trapping of hot electrons in the buffer is mitigated. Temperature-dependent transient measurement is also carried out to investigate the recovery process for these two type of CC. Two types of trap levels are identified in the unpassivated and Si3N4 passivated devices, respectively. The trap level E1 with an activation energy of 0.08 eV is supposed to be related to the surface trapping, while E2 with an activation energy of 0.22 eV is located in the buffer layer.

Cheng Z, Xu Z, Xu S, Wang X. Temperature dependent behavior of thermal conductivity of sub-5 nm Ir film: Defect-electron scattering quantified by residual thermal resistivity. Journal of Applied Physics. 2015;117(2):024307.

Cheng Z. Temperature-dependent thermal and electrical conduction in metallic nanostructures. 2015.

Tang H-H, Liu* P-K. Terahertz far-field super-resolution imaging through spoof surface plasmons illumination. Optics Letters. 2015;40(23):5822-5825.

Tang H-H, Liu* P-K. Terahertz metalenses for evanescent wave focusing and super- resolution imaging. Journal of Electromagnetic Waves and Applications. 2015;29(13):1776-1784.

Shao L, Stairs I, others. Testing Gravity with Pulsars in the SKA Era. In: PoS. Vol. AASKA14. ; 2015. pp. 042.

Du C-H, Lee H, Qi X-B, Liu* P-K, Chang* T-H. Theoretical study of a fourth-harmonic 400-GHz gyrotron backward-wave oscillator. IEEE Transactions on Electron Devices. 2015;62(1):207-212.

Du C-H, Lee H, Qi X-B, Liu* P-K, Chang* T-H. Theoretical study of a fourth-harmonic 400-GHz gyrotron backward-wave oscillator. IEEE Transactions on Electron Devices [Internet]. 2015;62(1):207-212. 访问链接 Abstract

The requirement of strong magnetic field is one of the major difficulties for terahertz gyrotrons. A plausible solution is to operate at higher cyclotron harmonic denoted as s, in which the magnetic field strength is reduced to 1/s of the value for the fundamental harmonic operation. This paper presents a systematic theoretical investigation of a fourth-harmonic 400-GHz gyrotron backward-wave oscillator with relatively high efficiency. An axis-encircling electron beam is employed to suppress the mode competition. The operating mode is the TE41 mode. The efficiency and bandwidth are optimized for the magnetic field tuning. Simulations suggest that the fourth-harmonic circuit is capable of achieving highest interaction efficiency ~6.5%, and tunable bandwidth 2.8 GHz at 400 GHz. The weak beam-wave coupling and serious Ohm loss on the circuit wall limit the overall performance.

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