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利用MEC和LSC耦合的程序研究了EAST天线不同的相位差 对功率谱的影响及对功率沉积位置和电流分布的影响。通过计算发现,随着 的增大,功率谱的结构发生了改变,当 >200°后功率沉积和电流密度分布由原先的向外层移动变为向内层移动; =200°时形成一个离轴最远的驱动电流, =120°、 =260°时分别得到电流强度最小和最大的驱动电流。因此可以通过选取合适的天线相位差 ,实现对低杂波功率沉积和驱动电流剖面的控制。     

PIC Simulation of Current‐Driven Buneman Instability in Presence of Collisional and Thermal Effects

Collisional and thermal effects on the nonlinear evolution of Buneman instability in an unmagnetized current‐driven plasma are investigated by particle in cell simulations. These simulations show that, as the time passes, the electron distribution function profiles deviate from initial shifted Maxwellian distribution and the electron phase‐space holes can be formed. The electron distribution function profiles also indicate the counter‐streaming and plateau formation. Moreover, the contour of the electric field and profiles of the growth rate display the resonance condition for this instability. Finally, the time evolution of the electric field energy density and ion kinetic energy in the presence of collisional and thermal effects are presented. These evolutions illustrate that in the presence of collisions, the growth rate of the Buneman instability is smaller than the collisionless case. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Three port gyrator circuits using transconductance amplifiers or generalized conveyors

The three port gyrator was introduced and defined in [1] in two alternative forms of the admittance matrix (Y). Four alternative realizations of the three port gyrator using three transconductance amplifiers (TA) are given, three of them are new. Sixteen alternative three port gyrator circuits using four current conveyors (CCII) or four inverting current conveyors (ICCII) or a combination of both of them and four grounded resistors are given. Eight alternative three port gyrator circuits using two CCII or two ICCII or a combination of both of them, balanced output current conveyors (BOCCII) and three grounded resistors are also introduced. Eight alternative three port gyrator circuits using two CCII or two ICCII or a combination of both of them, differential voltage current conveyors (DVCC) and three grounded resistors are also introduced. Finally four equivalent three port gyrator circuits using a combination of DVCC and BOCCII and two grounded resistors are also introduced, three of them are new.     

Solid-state electron transport in Mn-, Co-, holo-, and Cu-ferritins: Force-induced modulation is inversely linked to the protein conductivity

In this work, solid-state electron transport through the three metal core reconstituted ferritins, namely, Mn(III)-ferritin, Co(III)-ferritin, and Cu(II)-ferritin, has been probed and compared to the electron transport via the naturally-occurring iron-containing holoferritin and the metal-free apoferritin using current sensing atomic force spectroscopy (CSAFS), which allows direct contact to be established with the protein molecules. The CSAFS results reveal that by applying compressional force, in varying degrees (17-66 nN) and for varying durations (1 min, 2 min, and 3 min), the electronic conductivity of these proteins can be increased (for greater amount of force applied or for prolonged application of force) or decreased (for lesser amount of force applied or for shorter application time). The compressional modulation of the electronic conductivities appears to be due to compression of the protein part. The observation of the order of electronic conductivities of Mn-, holo-, Co-, and Cu-ferritins at almost any specific force value being similar to that of the free metal conductivities indicates that the absolute conductivity values are directly influenced by the metal core. Importantly, we found that more conductive the protein is, less modulated it can be. These findings could be highly relevant in realizing metalloprotein-based bioelectronic devices, especially where the electrode-protein-electrode sandwich configurations are employed.     

医疗内窥检查超低功耗电感复用射频前端芯片设计

本文阐述了一种应用于医疗探测的工作在407～425MHz频段的电感复用射频前端芯片。本射频前端芯片由超低功耗电流复用LNA、Mixer和高发射效率PA构成。本文提出了一种新型的电感复用射频前端结构,通过接收机和发射机输入输出共用电感,不仅有效避免了双工器的使用降低了芯片成本,而且节省了片外元件的数量,满足了高集成度的应用要求。该射频前端芯片在0.18μm标准CMOS工艺下进行了流片,芯片面积0.43mm2。作为接收机和发射机使用时,射频前端功耗分别为0.45mA和1.53mA,是一款超低功耗、高集成度的射频前端芯片。     

Explicit and implicit solutions of a generalized Camassa-Holm Kadomtsev-Petviashvili equation

In this paper, a generalized Camassa-Holm Kadomtsev-Petviashvili (gCH-KP) equation is studied. As a result, under different parameter conditions, the bounded travelling wave solutions such as periodic waves, periodic cusp waves, solitary waves, peakons, loops and kink waves are given, and the dynamic characters of these solutions are investigated.     

Transport and storage properties of CrSi2/Si junctions made using the CAPVD technique

p-CrSi₂/n-crystSi and p-CrSi₂/p-crystSi hetero junctions produced by cathodic arc physical vapor deposition were worked out by means of capacitance–voltage–temperature (C–V–T) and current–voltage–temperature (I–V–T) measurements to investigate storage and transport properties. Former measurement on p-CrSi₂/n-crystSi structure confirmed an abrupt type junction together with a building voltage at the proximity of 0.7 V. Though a fairly well rectification ratio (10³ at ±2 V) was realized by I–V measurement, it became deteriorated with the increase in ambient temperature. From temperature dependence of I–V variations, distinct conduction mechanisms were identified. In forward (reverse) direction trap assisted single-multistep tunneling recombination (generation) and space-charge limited current flow that corresponded to low and high bias voltage regions, respectively, were identified. Moreover, an activation energy (E_A) determined from the slopes of I–V–T curves as 0.22 and 0.26 eV was interpreted as the energy position of a chromium–boron (Cr–B) complex-type point defect residing in n/p doped c-Si semiconductor in CrSi₂/n–c-Si and CrSi₂/p–c-Si junctions. The retrieved E_A was in agreement with the recent DLTS measurement. Based on the experimental observations, schematic current path was built to interpret I–V/C–V behaviors. The model was successful in explaining the decrease in measured capacitance under large forward bias voltage reported for the first time by us for the present CrSi₂/Si junctions.