δ掺杂样品中空穴态的新行为

用有效质量理论研究了δ掺杂势中电子和空穴的行为。发现能量接近于δ势垒峰的空穴穿越势垒时能产生一系列谐振态。这些状态中的空穴波函数汇聚在势垒峰周围而同量子限制在势阱中的电子波函数交叠,产生光跃迁。用MBE生长的δ掺杂样品进行光调制光谱测量,发现明显的带间跃迁峰。测得的光谱峰同理论计算的能级相吻合,证实了δ势垒中空穴的新行为。     

利用表面等离子体波共振效应(SPRE)对角度与共振波长关系的研究

本文利用了Kretchmann模型的表面等离子体波共振效应，研究了共振波长对入射角变化的敏感性，从而为研制一种新的角度传感器提供了依据。     

有限元法应用于微波和光波器件的问题和发展

本文就有限元法应用于微波和光波器件的原理、问题和最新进展作了综合评述。文中讨论了适用于不同问题的变分公式的意义；着重讨论了避免和消除虚模的方法和处理开放边界的技术；还对代表该领域发展趋势的三个方面，即边棱元法。非线性结构及有限元程序的前后处理问题进行了评论和展望。     

硅微板条谐振式传感器谐振频率分析及计算

对硅微机械谐振式传感器的谐振频率计算提出了新的物理模型—两端固支薄板条模型，该模型不同于常说的硅桥（梁）或硅弦模型。计算结果表明该模型更符合实际，优于有关文献结果。     

新型零电压开关多谐振变换器

论述了一种新型多谐振变换器．通过开关型吸收电路使晶体管电压应力大大降低．理论分析和实验结果证明该变换器具有更优越的工作性能．     

电网电压不平衡且严重畸变时的软件锁相技术

针对传统软件锁相环（SPLL）在三相电压不平衡且严重畸变条件下不能准确跟踪电网电压的频率和相位的问题。本文提出了一种基于相序解耦（SDR）级联二阶广义积分（SOGI）的新型软件锁相模型,通过SDR和SOGI实现了正负序分离,电压基波提取,以及滤波功能,有效地消除了负序分量、谐波分量对准确获取频率和相位信息的影响。仿真结果表明在三相电压不平衡且严重畸变的条件下,该新型SPLL能够准确地锁定电网电压的频率和相位,从而有效性地验证了新方法的正确性。     

A relativistic extension of the complex scaling method using oscillator basis functions

We develop the complex scaling method within the relativistic framework by expanding the Dirac spinors in the complete set of eigensolutions of a harmonic oscillator potential, and present the theoretical formalism of describing the discrete bound and resonant states on the same footing. Based on a well established and frequently used model, we demonstrate the utility and applicability of the extended method and examine the stability of the results with respect to the variations of the parameters of the model. Satisfactory agreements are found for all the calculated results in comparison with some other calculations in references. Especially, the present calculation in the nonrelativistic limit gives a consistent result with that in the nonrelativistic calculation.     

Piezoelectric cantilever sensors with asymmetric anchor exhibit picogram sensitivity in liquids

We show for the first time that self-exciting and self-sensing piezoelectric cantilevers consisting only of lead zirconate titanate (PZT) measure resonance only if they are asymmetrically anchored. Symmetric-anchoring did not give rise to electrically measurable bending resonant modes in the 0-100 kHz range. Sensitivity of first and second bending mode resonances was characterized in a flow apparatus using small density changes in liquid (0.003-0.01 g/cm³) and by dodecanethiol chemisorption at 30 pM. Density change results were consistent with existing models of submerged cantilevers, and yielded mass-change sensitivity of ∼33 ng/Hz and 217 pg/Hz for the first two modes. In chemisorption experiments, where binding was localized to 1 mm² distal tip of the PZT cantilever, sensitivity improved by an order of magnitude to 2 pg/Hz and 414 fg/Hz for the same two resonant modes.     

On The Modeling of Twin Rotor MIMO System Using Chirp Inputs as Test Signals

This paper addresses the modeling problem for the twin rotor multi input multi output system. To develop experimental data, this popular commercial laboratory model of a helicopter from Feedback Instruments Ltd is excited with band limited chirp inputs. The conclusions drawn in this paper lead to four significant achievements: 1) derivation of a linear nominal model for Twin Rotor MIMO System, TRMS in short, from its equivalent nonlinear mathematical representation; 2) dynamic modeling of TRMS; 3) determination of non‐minimum phase dynamics; and 4) determination of linear operating region. The work considers systematic study of the system dynamics of TRMS and analytical treatment of its identified data leading to derivation of the RHP zero dynamics followed by pictorial illustrations indicating resonant modes associated with the plant. The method used in the present paper can be essentially used in modeling of 2 × 2 plants exhibiting non‐minimum phase dynamics and model uncertainties.     

微结构谐振梁式压力传感器研究

利用微电子机械加工技术成功地研制出电势激励、压阻拾振的高精度硅谐振梁式压力传感器,传感器的谐振器的品质因素Ｑ值大于１７０００。采用扫描检测方式和闭环自激振荡方式测定压力传感器的压力特性,其压力测试范围为０￣４００ｋＰａ,线性相关系数为０．９９９９５,测试精度小于０。０６％Ｆ．Ｓ。