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Comparison and analysis on effective observation area of tensor CSAMT by numerical simulation method 期刊论文  OAI收割
CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION, 2017, 卷号: 60, 期号: 8, 页码: 3278-3287
作者:  
Liu Zhi-Xing;  Xue Guo-Qiang;  Zhang Lin-Bo
  |  收藏  |  浏览/下载:19/0  |  提交时间:2017/11/24
Distribution of electric field and design of devices in GaN avalanche photodiodes 期刊论文  OAI收割
Science China-Physics Mechanics & Astronomy, 2012, 卷号: 55, 期号: 4, 页码: 619-624
作者:  
Baoshun Zhang (张宝顺);  ShuMing Zhang;  Hui Yang (杨辉)
收藏  |  浏览/下载:21/0  |  提交时间:2013/01/22
Analysis of a diffractive microlens using the finite-difference time-domain method (EI CONFERENCE) 会议论文  OAI收割
作者:  
Liu Y.;  Liu H.;  Liu H.;  Liu H.;  Liu Y.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
The finite-difference time-domain (FDTD) method is used as rigorous electromagnetic analysis model to calculate the field for a diffractive microlens (DML). The FDTD is used for the entire solution rather than using a near- to far-field propagation method to obtain the far-field energy distribution  thus  all the results are vector based. We derived a formula to calculate the magnitude of electric field  which is time dependent and can be used to graphically show the light wave propagation and focusing process through a DML. Both the comparison and the integral methods are presented to obtain wave amplitude in full solution space  and the distribution of light energy behind a DML is illustrated based on the wave amplitude. The formula of diffractive efficiency of the DML is derived from a time-averaged Ponyting vector  which can indicate the propagation direction of light energy. Application of these formulations in the analysis of a DML example demonstrates the high accuracy and efficiency of our method. 2010 Society of Photo-Optical Instrumentation Engineers.  
Rigorous vector analysis of diffractive microlens by using of finitedifference time-domain method (EI CONFERENCE) 会议论文  OAI收割
2009 International Conference on Optical Instruments and Technology, OIT 2009, October 19, 2009 - October 22, 2009, Shanghai, China
作者:  
Liu Y.;  Liu H.;  Liu H.;  Liu H.;  Liu Y.
收藏  |  浏览/下载:32/0  |  提交时间:2013/03/25
We use finite difference time domain (FDFD) method as rigorous vector analysis model to simulate the focusing process of diffractive microlens (DML). Differing with most analysis model which the near field distributions are calculated by FDTD and then far field are obtained by using of propagation method  we obtain the fields in whole computational space by using of FDTD only. The advantages are that all the results are vector based and the computational time is saved greatly. In this paper  we present two methods to obtain wave amplitude  one is comparison method  and the other is integral method. Depending on wave amplitude in the whole computational space  one can conveniently obtain distributions of electric field intensity and calculate the time-average Poynting vector. We also present the formulation for calculating diffractive efficiency of DML based on time-average Poynting vector which denotes energy flow. As demonstration  a DML is analyzed by using of these algorithms. The time depended graphic results of FDTD show the process of wave propagation. The distribution of electric field intensity illustrates the focusing of the normal incident light. The focus pattern in the focal plane is also show. The diffractive efficiency of the DML is calculated by using of the energy flow method in this paper. The results show the high accuracy and efficiency of the model. 2009 SPIE.  
Simulation study of ring current properties during main phase of storm 期刊论文  iSwitch采集
Acta physica sinica, 2007, 卷号: 56, 期号: 12, 页码: 7346-7354
作者:  
Wang Xin-Yue;  Liu Zhen-Xing;  Chao, Shen
收藏  |  浏览/下载:28/0  |  提交时间:2019/05/10
Fabrication and electron emission of carbon microtubes (EI CONFERENCE) 会议论文  OAI收割
Technical Digest of the 18th International Vacuum Nanoelectronics Conference, IVNC 2005, July 10, 2005 - July 14, 2005, Oxford, United kingdom
作者:  
收藏  |  浏览/下载:40/0  |  提交时间:2013/03/25
Carbon nanotubes have been attracting attention because of their unique physical properties and their application potential for field emission cathode. Carbon nanotubes possess the following properties favorable for field emission material  such as a high aspect ratio and sharp tip  high chemical stability  high mechanical strength  stable at high temperature. Some research works on carbon nanotubes field emitter and field emission display have been reported. Here  a kind of carbon microtubes and its field emission properties are introduced. They have some different properties with carbon nanotubes  and the density is lower than carbon nanotubes bundles. These carbon microtubes are directly synthesized by liquidoid epitaxy method on silicon substrates at low temperature. The field emission properties of carbon microtubes are reported too. Carbon microtubes film is synthesized in liquid by electrolysis. The graphite plate is as anode  and n-silicon substrate with resistivity of 4-8 cm is as cathode. The electrolysis current is about 5-8mA/cm2  and applied voltage is 800-1500V. Temperatures of the methanol base solution is maintained at 60C in process of deposition of carbon microtubes. Carbon microtubes film is observed by scanning electron microscopy(SEM)  as shown in fig.1(a  b). The wall's thickness of carbon microtube is about 60nm. The diameter of carbon microtube is about 0.8 m. Raman spectrum of carbon microtubes film shows the two peaks at 1342and 1560cm-1. The field emission properties of carbon microtubes are measured in high vacuum chamber(10-5Pa). The emission area of carbon microtubes is 0.5cm 0.5cm. The threshold of field emission of the carbon microtubes film is about 3.6V/ m. Field emission property of carbon microtubes film is shown in fig.2. Another  when the electric field between anode and cathode is 10V/ m  the electric field distribution on single carbon microtube is also given after calculation according to electric field theory. Fig 3 shows that electric field distribution vertical section on the of single carbon microtube top with 2 m of highness. These results may help us to understand field emission properties of carbon microtubes. According to research results  it is found that liquidoid synthesis is simple method to produce carbon microtubes cold cathode material  and the carbon microtubes have better field emission properties. 2005 IEEE.