pcb电源布线设计-印制导线温升与导线宽度和负载电流的关系

本文阐述了PCB电源分配网络布线需要关注的几个方面,提供了量化设计的方法和工具.结合案例,介绍了电源通流能力可靠性设计的方法.     

Dependence of off-leakage current on channel film quality in poly-Si thin-film transistors and analysis using device simulation

The dependence of off-leakage current on channel film quality in poly-Si thin-film transistors has been analyzed using two-dimensional device simulation. It is found that the off-leakage current decreases as the intragrain trap density decreases for the low V_gs. This is because the Phonon-assisted tunneling with Poole-Frenkel effect is the dominant mechanism of the carrier generation and the generation rate of carrier pair decreases as the intragrain trap density decreases. On the other hand, the off-leakage current slightly increases as the intragrain trap density decreases for the high V_gs. This is because the band-to-band tunneling is the dominant mechanism and the influence of the intragrain trap density to the carrier conductance is larger than that to the generation rate.     

Bandlet image estimation with model selection

To estimate geometrically regular images in the white noise model and obtain an adaptive near asymptotic minimaxity result, we consider a model selection based bandlet estimator. This bandlet estimator combines the best basis selection behavior of the model selection and the approximation properties of the bandlet dictionary. We derive its near asymptotic minimaxity for geometrically regular images as an example of model selection with general dictionary of orthogonal bases. This paper is thus also a self-contained tutorial on model selection with orthogonal bases dictionary.     

Effects of contact electrode size on the characteristics of polycrystalline-Si p-i-n solar cells

The effects of contact electrode size on the photo-voltaic characteristics of polycrystalline-Si p-i-n solar cells have been studied,with respect to a unit-cell pitch size of 1μm width.For the non-transparent Al contact electrode with a contact width of 0.05-0.2μm,the short-circuit current is obviously reduced with increasing contact width,due to a larger area of optical reflection by the electrode.On the other hand,even when using a transparent ITO(indium-tin-oxide) electrode,a larger width of contact e...     

Gas damping force noise on a macroscopic test body in an infinite gas reservoir

We analyze here the force noise associated with the mechanical damping of a test body surrounded by a large volume of rarefied gas, considering the statistics of momentum exchange in inelastic molecular collisions. In addition to calculating the force noise on a cube, sphere, and cylinder, we discuss the limits in applying this analysis to experimental configurations in which the test body is surrounded by an enclosure that is only slightly larger than the test body itself.     

基于AMESim的双电机消隙伺服系统的仿真分析

在大惯量负载精密跟踪雷达伺服系统中,齿隙会影响系统跟踪精度和稳定性.文中利用AMEsim提供的机械库、电机驱动库、信号库、动力传动库完成仿真模型的建立.通过采用双电机消隙驱动系统,消除了齿隙对跟踪性能的影响.另外,还对影响系统跟踪性能的多个环节进行了仿真分析.AMESim软件在系统设计、调试、验证中起到很好的作用.     

分解区域方法在涡流检测仿真中的应用

随着现代制造业的发展,涡流检测仿真问题日渐复杂。传统的单一求解区域方法的运用遇到瓶颈,而分解区域方法将复杂的单一区域上的求解转化为较简单的若干个子区域上的求解,克服了传统方法遇到的困难。该文主要介绍分解区域方法在涡流检测仿真中的应用。     

老练条件的变化对铝电解电容器质量的影响

铝电解电容器的老练直接影响产品的质量。老练条件的变化对铝电解电容器的电容量、漏电流有一定的影响。在额定老练电压、＋ ９０℃５ｈ 条件下老练， 能更好地改善产品质量， 提高产品合格率。采用脉冲老练可以缩短老练时间， 但漏电流回升速度快     

晶体管发射极电流集边效应物理意义之探讨

由基区电阻的自偏压引起的晶体管发射极电流集边效应，是限制晶体管承载电流能力的因素之一。