Precise Extraction of Charge Carrier Mobility for Organic Transistors

Unreliable mobility values, and particularly greatly overestimated values and severely distorted temperature dependences, have recently hampered the development of the organic transistor field. Given that organic field‐effect transistors (OFETs) have been routinely used to evaluate mobility, precise parameter extraction using the electrical properties of OFETs is thus of primary importance. This review examines the origins of the various mobilities that must be determined for OFET applications, the relevant extraction methods, and the data selection limitations, which help in avoiding conceptual errors during mobility extraction. For increased precision, the review also discusses device fabrication considerations, calibration of both the specific gate‐dielectric capacitance and the threshold voltage, the contact effects, and the bias and temperature dependences, which must actually be handled with great care but have mostly been overlooked to date. This review serves as a systematic overview of the OFET mobility extraction process to ensure high precision and will also aid in improving future research.     

宽带数字接收机IQ不平衡估计与自适应补偿算法

针对宽带调制解调技术中广泛存在的IQ不平衡问题,在IQ不平衡模型及补偿原理的分析基础上提出了一种宽带数字接收机IQ不平衡估计与自适应补偿算法。首先利用解调数据对IQ不平衡参数进行实时估计,然后利用估计参数对接收信号进行自适应补偿。实验结果表明,所提算法可以有效解决宽带调制解调系统中普遍存在的IQ不平衡问题,提升系统误码性能。     

Controller design for distributed parameter systems with time delays in the boundary feedbacks via the backstepping method

For a distributed parameter system with an input delay in the boundary, a feedback control law is presented by means of the backstepping method. The square integrability of input signal is verified based on the target system. Then, the boundedness and invertibility of the corresponding backstepping transformation are proved under the regularity of system and the admissibility of feedback operator. Thus, the resulting closed-loop system is shown to be exponentially stable. Finally, as an application, a numerical simulation of a one-dimensional Schrödinger equation with a delay input is carried out, and the simulation results demonstrate the effectiveness of the suggested control law.     

Dual effect synergistically triggered Ce:(Y,Tb)3(Al,Mn)5O12 transparent ceramics enabling a high color-rendering index and excellent thermal stability for white LEDs

Ce:Y₃Al₅O₁₂ transparent ceramics (TCs) with appropriate emission light proportion and high thermal stability are significant to construct white light emitting diode devices with excellent chromaticity parameters. In this work, strategies of controlling crystal-field splitting around Ce³⁺ ion and doping orange-red emitting ion, were adopted to fabricate Ce:(Y,Tb)₃(Al,Mn)₅O₁₂ TCs via vacuum sintering technique. Notably, 85.4 % of the room-temperature luminescence intensity of the TC was retained at 150 °C, and the color rendering index was as high as 79.8. Furthermore, a 12 nm red shift and a 16.2 % increase of full width at half maximum were achieved owing to the synergistic effects of Tb³⁺ and Mn²⁺ ions. By combining TCs with a 460 nm blue chip, a warm white light with a low correlated color temperature of 4155 K was acquired. Meanwhile, the action mechanism of Tb³⁺ ion and the energy transfer between Ce³⁺ and Mn²⁺ ions were verified in prepared TCs.     

Phase equilibrium in systems based on oxides of zirconium,lanthanum and samarium

According to the results of the samples studied by X-ray diffraction and microstructural analyzes the phase equilibria in the binary La₂O₃ – Sm₂O₃ and ternary ZrO₂ – La₂O₃ – Sm₂O₃ systems were studied. The boundaries of the phase fields of the binary system are specified and an isothermal cross section of the ternary state diagram of the ZrO₂ – La₂O₃ – Sm₂O₃ system at a temperature of 1500 °C is constructed. No new phases have been identified in the studied systems. It is established that in the ternary system ZrO₂ – La₂O₃ – Sm₂O₃ at 1500 °C fields of solid solutions on the basis of cubic (F) modification with structure of fluorite type, tetragonal (T) modification of ZrO₂, monoclinic (B) modifications of Sm₂O₃, hexagonal (A) are formed. La₂O₃, as well as an ordered phase with a structure of the type of pyrochlore Ln₂Zr₂O₇ (Py). The boundaries of the phase fields and the parameters of the unit cells of the formed phases are determined. A characteristic feature of this isothermal cross section is the formation of a continuous series of solid solutions based on the phase of the pyrochlore type La₂Zr₂O₇ (Sm₂Zr₂O₇). The limiting solubility of Sm₂O₃ in the ordered phase La₂Zr₂O₇ is 16 mol. % along the section Sm₂O₃- (67 mol.% ZrO₂ - 33 mol.% La₂O₃). The solubility of La₂O₃ in the solid solution Sm₂Zr₂O₇ is slightly less and is 11 mol. % along the section La₂O₃- (67 mol.% ZrO₂ - 33 mol.% Sm₂O₃). The isothermal cross-section of the state diagram of the ZrO₂ – La₂O₃ – Sm₂O₃ system at 1500 °C is characterized by the presence of three three-phase (Py + T + F), (A + Py + B), (Py + F + B) and eight two-phase (A + Py), (B + A), (B + Py), (F + B), (T + F), (Py + T), (F + Py-two) areas.     

一种磁控管用扼流线圈仿真设计

采用电路仿真软件仿真滤波组件S参数曲线,观察曲线随器件参数的变化;介绍利用三维全波电磁仿真软件HFSS简化设计流程的方法,并与测试结果对比。结果表明:利用3D仿真软件在满足器件设计精度的同时可以简化线圈的设计流程。     

Distributed Kalman filter for linear system with complex multi-channel stochastic uncertain parameter and decoupled local filters

This article considers a distributed Kalman filtering problem for linear system contaminated by complex multi-channel random uncertain parameter in which a number of nodes cooperative without central coordination to estimate a common state based on local measurements and data received from neighbors. We propose an approach to eliminate this error propagation. The proposed local filters are guaranteed to be stable under some mild conditions on certain global structural data, and their fusion yields the centralized Kalman estimate. Then, we extend this method to smoothing and deconvolution algorithm. Finally, simulation experiments demonstrate the validity of the proposed approach.     

基于时间常数的核电厂主循环泵惰转模型开发与验证

在核电厂初步设计阶段，针对反应堆进行的工况设计和安全分析均需要泵的惰转模型提供输入。现有泵的惰转模型几乎都需要已知泵的设计参数和管路系统阻力特性，但在电厂初步设计阶段，泵的详细结构设计尚未开展，管路阻力特性也难以获取。针对上述问题，提出了两种基于时间常数的主泵惰转特性曲线计算模型，并采用核电厂主循环泵的惰转试验数据进行了对比验证。分析结果表明，模型A在高转速时与试验值吻合较好，低转速时偏差较大，而模型B在整个惰转过程中与试验值均较接近，可用于核电厂的工况设计和安全分析。