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Studies on CsBr with Synchrotron Radiation Under Ultrahigh Pressure up to 115GPa

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Chinese Physics Letters 1998年第4期15卷 284-286页

作者： WANG li-jun CHEN liang-chen li feng-ying GU Hui-cheng ZHOU Lei CHE Rong-zheng Institute of Physics Chinese Academy of SciencesBeijing 100080

In situ high pressure energy dispersive x-ray diffraction experiments have been carried out on CsBr by using diamond anvil cell device with synchrotron radiation *** maximum pressure is 115 *** structure of CsBr is changed from simple cubic phase to tetragonal phase at pressure about 53 GPa,marked by the splitting of its strongest diffraction line(110).At pressure above 98GPa,the color change of CsBr from transparent to red-brown was *** pressure-induced transition from insulator to metal is found at higher pressure up to 115GPa.

关键词： GPa CsBr cubic

B→Xsγ, Xsl+l~-Decays and Constraints on Mass Insertion Parameters in MSSM

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Communications in Theoretical Physics 2006年第10期46卷 687-696页

作者： XIAO Zhen-Jun,~+ li feng-ying, and ZOU Wen-Jun Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210097, China Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210097 China

In this paper, we study the upper bounds on the mass insertion parameters (δ~q)in the minimal supersymmetric standard model. We found that the information from the measured branching ratio of B→Xl+l~-decaycan help us to improve the upper bounds on the mass insertions parameters(δ. Some regions allowed by thedata of Br(B→Xγ)are excluded by the requirement of an SM-like C(m)imposed by the data of Br(B→Xl+l~-).

关键词： B meson decay the minimal supersymmetric standard model mass insertion

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二极管组高性能光电探测器阵列的设计

光子学报 2016年第1期45卷 110-116页

作者：柯昂文化锋(指导) 龙丹桂刘春李健 li ying-feng 宁波大学信息科学与工程学院浙江宁波315211 Atech System 6110W.Highway 290AustinTX 78735USA

针对行波光电探测器阵列仅提高了光电探测器的输出功率而输出带宽未得到改善的特点,提出了一种由光电二极管组构成的高性能行波光电探测器阵列新结构.即把两个光电二极管级联后再将两个级联支路并联,然后在光电二极管组上串联电容构成... 详细信息

针对行波光电探测器阵列仅提高了光电探测器的输出功率而输出带宽未得到改善的特点,提出了一种由光电二极管组构成的高性能行波光电探测器阵列新结构.即把两个光电二极管级联后再将两个级联支路并联,然后在光电二极管组上串联电容构成单个阵列单元,再按照阵列式结构将这些阵列单元用电感连接起来构成新型行波光电探测器阵列.对比分析了行波光电探测器阵列新旧结构的功率合成、频率响应和回波损耗特性.在应用同等数量二极管的条件下,新型行波光电探测器阵列输出功率减少了一半,但工作带宽提高了一倍.此外,回波损耗随着阵列中应用二极管数目的增加相对于原阵列而言改善得更加明显.研究结果表明,本文提出的行波光电探测器阵列新结构能够在增加输出功率的同时提高工作带宽,更好地满足未来光载无线通信对光电探测器高功率宽带宽的需求.

关键词：电子电路光载无线通信行波探测器阵列功率合成器件光纤光电二极管频率响应微带线

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Ultrasonic Properties of the MgB_(2) Superconductor

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Chinese Physics Letters 2001年第10期18卷 1369-1370页

作者： li Shao-Chun WANG Ru-Ju li feng-ying liU Zhen-Xing ZHU Jia-lin YU Ri-cheng JIN Chang-Qing Laboratory for Extreme Condition Physics Institute of Physicsand Center for Condensed Matter PhysicsChinese Academy of SciencesBeijing 100080 Beijing Center for High Pressure Research Chinese Academy of SciencesBeijing 100080

The sound velocities of longitudinal and shear waves are measured on a polycrystalline MgB_(2) superconductor with Tc of 39 K. The specimen used in the experiments is pressed and heated using the MgB_(2) powder. The elastic moduli, Debye temperature and specific heat at room temperature are obtained based on sound velocity data. The results indicate that the velocities are much higher than those in the usual materials, while elastic constants remain reasonably soft, which may be due to the high transition temperature of the MgB2 superconductor.

关键词： heated Superconductor superconductor

Thin-Thick Film Transitions on a Planar Solid Surface： A Density Functional Study

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Chinese Physics Letters 2010年第3期27卷 247-250页

作者：于养信李英峰郑远翔 State Key Laboratory of Chemical Engineering Department of Chemical Engineering Tsinghua University Beljing 100084

A weighted density functional theory is proposed to predict the surface tension and thin-thick film transition of a Lennard-Jones fluid on a planar solid surface. The underlying density functional theory for the Lennard-Jones fluid at low temperature is based on a modified fundamental measure theory for the hard-core repulsion, a Taylor expansion around zero-bulk-density for attraction, and a correlation term evaluated by the weighted density approximation with a weight function of the Heaviside step function. The predicted surface tension and thin-thick film transition agree well with the results from the Monte Carlo simulations, better than those from alternative approaches. For the Ar/CO2 system, the prewetting line has been calculated. The predicted reduced surface critical temperature is about 0.97, and the calculated wetting temperature is below the triple-point temperature. This is in agreement with the experimental observation.

关键词： Soft matter liquids and polymers Surfaces interfaces and thin films

Pressure Induced Phase Transition in TiB

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Chinese Physics Letters 2001年第9期18卷 1240-1241页

作者： li feng-ying CHEN liang-Chen WANG li-Jun GU Hui-Cheng WANG Ru-Ju CHE Rong-Zheng SHEN Zhong-Yi Institute of Physics Chinese Academy of SciencesBeijing 100080

In situ high pressure x-ray diffraction and electrical resistance experiments on TiB have been carried out by using a diamond anvil cell device. The results revealed that the sample undergoes a first-order phase transition at pressures of 3.5-5.0 Gpa and 4.0-5.5 Gpa for the x-ray diffraction and electrical resistance experiments, respectively. The parameters of the state equation are calculated before and after the phase transition and compared with the values calculated by Mohn et al. [J. Phys. C: Solid State Phys. 21(1988)2829] using the augmented spherical wave method.

关键词： resistance Transition transition

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行波光电二极管级联阵列输出功率合成研究

光子学报 2015年第3期44卷 42-46页

作者：文化锋聂秋华刘太君徐铁峰应祥岳 CLARK Kevin li ying-feng 宁波大学信息科学与工程学院浙江宁波315211 Intelligent Epitaxy Technology 1250 E Collins BlvdRichardsonTX 75081USA Atech Systems 6110 W.Highway 290AustinTX 78735USA

针对未来光载无线通信所需的高功率、大带宽的光电探测器,提出了一种行波光电二极管级联阵列功率合成电路.先将行波光电二极管级联,再按照阵列式结构将多组级联的光电二极管组合起来,实现射频功率合成,以获得高功率、大带宽的射频信号.... 详细信息

针对未来光载无线通信所需的高功率、大带宽的光电探测器,提出了一种行波光电二极管级联阵列功率合成电路.先将行波光电二极管级联,再按照阵列式结构将多组级联的光电二极管组合起来,实现射频功率合成,以获得高功率、大带宽的射频信号.采用EDA工具,对该光电转换射频功率合成电路进行仿真模拟.仿真结果表明,该功率合成电路可以有效地将各光电二极管的射频输出信号进行功率合成,功率合成后的信号带宽显著增加,仿真结果与理论分析完全一致.此外,电路分析表明,增加该功率合成电路中的高阻微带线的特性阻抗可以有效提高其输出射频信号的带宽.

关键词：行波级联阵列功率合成光电二极管光电转换

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Dl- 3 -n-Butylphthalide, a multi -target drug for the treatment of acute ischemic stroke

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中国药理通讯 2005年第4期22卷 54-55页

作者： Zhang li - ying feng yi - pu Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100050

基于桥接T型光电探测器阵列的功率合成研究与设计

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光电子．激光 2018年第9期29卷 950-956页

作者：徐梦洁文化锋徐敏松杜洋洋 li ying-feng 施锋宁波大学信息科学与工程学院浙江宁波315211 Atech System 6110W.Highway 290AustinTX 78735USA Department of Electrical Engineering and Renewable Energy Engineering Oregon Institute of Technology3201 Campus DriveKlamath FallsOR 97601USA

针对行波探测器阵列(TWDA)仅提高了光电探测器的输出功率而输出带宽未得到改善的问题,本文提出了一种区别于TWDA的基于桥接T型光电探测器阵列新结构。本设计采用基于constant-R结构的桥接T型结构代替TWDA中的传统constant-K结构的方法 ... 详细信息

针对行波探测器阵列(TWDA)仅提高了光电探测器的输出功率而输出带宽未得到改善的问题,本文提出了一种区别于TWDA的基于桥接T型光电探测器阵列新结构。本设计采用基于constant-R结构的桥接T型结构代替TWDA中的传统constant-K结构的方法 ,从而形成人工传输线结构。即耦合微带线提供串连电感和所需要的互感,电容并联于其中一条微带线上,再将单个光电二极管嵌入到此人工传输线上,构成单个阵列单元,再按照阵列式结构将这些阵列单元有效级联起来构成桥接T型光电探测器阵列。仿真结果表明,所提出的桥接T型光电探测器阵列能够使多个光电探测器功率合成的同时提高工作带宽,虽然桥接T型光电探测器阵列合成功率相比于传统TWDA合成功率有稍许减少,但在工作带宽上却提高了2^(1/2)倍,减少的稍许合成功率可以通过增加级联数目加以补偿。

关键词：光电探测器行波探测器阵列功率合成桥接T型结构微带线工作宽带

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