On the extraction of the source and drain series resistances of MOSFETs

This article reviews and scrutinizes various proposed methods to extract the individual values of drain and source resistances (R_D and R_S) of MOSFETs, which are important device parameters for modeling and circuit simulation. In general, these methods contain three basic steps: (1) the extraction of the total drain and source resistance (R_D+R_S); (2) the extraction of the difference between the drain and the source resistances (R_D−R_S); and (3) the calculation of R_D and R_S from the knowledge of (R_D+R_S) and (R_D−R_S). These methods are tested and compared in the environments of circuit simulator, device simulation and measurements.     

Development of robust interconnect model based on design ofexperiments and multiobjective optimization

When designing an integrated circuit, it is important to take into consideration random variations arising from process variability. Traditional optimization studies on VLSI interconnect attempt to find the deterministic optimum of a cost function but do not take into account the effect of these random variations on the objective. We have developed an effective methodology based on TCAD simulation and design of experiments to optimize interconnect including the effects of process variations. The aim of the study is to search for optimum designs that both meet the performance specification and are robust with respect to process variations. A multiobjective optimization technique known as Normal Boundary Intersection is used to find evenly-spaced tradeoff points on the Pareto curve. Designers can then select designs from the curve without using arbitrary weighting parameters. The proposed methodology was applied to a 0.12 μm CMOS technology; optimization results are discussed and verified using Monte Carlo simulation     

有机硅改性环氧树脂

有机硅改性环氧树脂是近年来发展起来的既能降低环氧树脂内应力 ,又能增加环氧树脂韧性、耐高温性等性能的有效途径。二者相容性是有机硅改性环氧树脂的关键。本文综述了有机硅改性环氧树脂的各种改性方法、机理及研究进展     

Effects of cooling time and alloying elements on the microstructure of the gleeble-simulated heat-affected zone of 22% Cr duplex stainless steels

The effects of austenite stabilizers, such as nitrogen, nickel, and manganese, and cooling time on the microstructure of the Gleeble simulated heat-affected zone (HAZ) of 22% Cr duplex stainless steels were investigated. The submerged are welding was performed for comparison purposes. Optical microscopy (OM) and transmission electron microscopy (TEM) were used for microscopic studies. The amount of Cr₂N precipitates in the simulated HAZ was determined using the potentiostatic electrolysis method. The experimental results indicate that an increase in the nitrogen and nickel contents raised the δ to transformation temperature and also markedly increased the amount of austenite in the HAZ. The lengthened cooling time promotes the reformation of austenite. An increase in the austenite content reduces the supersaturation of nitrogen in ferrite matrix as well as the precipitation tendency of Cr₂N. The optimum cooling time from 800 to 500 °C (Δt _8/5) obtained from the Gleeble simulation is between 30 and 60 s, which ensures the austenite content in HAZ not falling below 25% and superior pitting and stress corrosion cracking resistance for the steels. The effect of manganese on the formation of austenite can be negligible.     

Effects of alloying elements on the mechanical properties and corrosion behaviors of 2205 duplex stainless steels

The effects of alloying elements on the microstructure, mechanical properties, and corrosion behaviors of duplex stainless steels (DSSs) have been investigated in this study. Experimental alloys were prepared by varying the concentrations of the constituent elements in DSSs. Hot ductility test, tensile test, charpy impact test, and corrosion test were performed to evaluate the properties of the experimental alloys. The results showed that the extent of edge cracking of DSSs increased with the increasing value of the crack sensitivity index (CSI). The higher the hot ductility index (HDI) was, the better the hot ductility of DSSs achieved. Austenite (γ) stabilizer generally caused a decrease in the strength and an increase in the charpy impact absorbed energy of the stainless steel. On the contrary, ferrite (α) former exerted its beneficial effect on the strength but became detrimental to the toughness of DSSs. The presences of sulfur and boron also caused a decrease in the impact energy, but nitrogen and carbon hardly affected the toughness within the concentration range tested in this study. The value of pitting nucleation potential (E _np ) of different nitrogen contents in 3.5 wt.% NaCl solution at room temperature was almost the same, but the value of pitting protection potential (E _pp ) among these alloys was increased with increasing the content of nitrogen. The susceptibility to stress corrosion cracking (SCC) of DSSs was high when tested in boiling 45 wt.% MgCl₂ solution. On the other hand, the time to failure of the experimental steels in 40 wt.% CaCl₂ solution at 100 °C was longer than that in MgCl₂ solution. Nitrogen could affect the SCC behavior of DSSs in CaCl₂ solution through the combinative effects by varying the pitting resistance and the slip step dissolution. An optimum nitrogen (N) content of 0.15 wt.% was found where the highest SCC resistance could be obtained. Although γ phase exhibited better resistance to SCC, cracks were found to penetrate through α and γ grains or to propagate along the α/γ interface. As a result, a mixed transgranular plus intergranular mode of fracture surface was observed.     

An EQCM study for a novel aromatic poly(amine-imide) electrochromic thin film

A new aromatic poly(amine-imide) electrochromic thin film synthesized with N,N-bis(4-aminophenyl)-N′,N′-diphenyl-1,4-phenylenediamine and 3,3′,4,4′-benzo-phenonetetra carboxylic dianhydride, abbreviated as poly(PD-BCD), was studied. The poly(PD-BCD) thin-film electrode has been characterized by cyclic voltammetry (CV) and electrochemical quartz crystal microbalance (EQCM). As the polymer chain acquires positive charge during the oxidation of poly(PD-BCD) to its radical cation state or dication state, the anions would insert into the polymer matrix in order to neutralize the charge. However, when the electrodes were cycled in electrolytes containing different cations, including 0.1 M LiClO₄/acetonitrile (ACN), 0.1 M NaClO₄/ACN and 0.1 M TBAClO₄/ACN, the experimental results revealed two mechanisms for the redox reaction. A plot of mass change (Δm) vs. accumulated charge (Q) gave a slope, from which the electrochromic mechanism can be extracted. The slopes of Δm–Q obtained from the CV–EQCM measurements in three electrolytes were different for the first redox stage, but the slopes were almost the same for the second redox stage. This means that, in addition to the involvement of anions, cations also play an important role in the first redox stage, however, the role of the cations is less in the second stage. Moreover, two reaction mechanisms for the two reaction stages of poly(PD-BCD) are proposed in this study.     

Heat transfer of a radially rotating furrowed channel with two opposite skewed sinusoidal wavy walls

An experimental study of heat transfer in a radially rotating furrowed channel with two opposite walls enhanced by skewed sinusoidal waves was performed to generate the full-field Nusselt number (Nu) data over two wavy walls. Although the static wavy channel has been proven as an effective heat transfer enhancement (HTE) measure, no previous study examined its heat transfer performances with rotation. As another first-time attempt for turbine cooling researches, the Nu scans over the entire rotational leading (stable) and trailing (unstable) walls were acquired using the infra-red thermography which proved highly advantageous due to its capability to examine the rotating buoyancy effects in details. A selection of experimental data illustrates the full-field Nu variations responding to the changes of Reynolds (Re), rotation (Ro) and buoyancy (Bu) numbers. Parametric analysis is subsequently followed to disclose the individual and interdependent Re, Ro and Bu effects on Nu in the attempt to derive the heat transfer correlations for the area-averaged Nu over the developed flow region $\left({\overline{Nu}}_{\text{FD}}\right)$ on the rotational leading and trailing wavy walls. Within the parametric ranges tested, the rotational leading and trailing ${\overline{Nu}}_{\text{FD}}$ values respectively fall between 3.4–4.3 and 4.2–6.4 times of the Dittus–Boelter datum, which grant the potential applicability of wavy channel as a HTE measure for cooling of gas turbine rotor blades.     

木粉高填充改性PE及PP再生料的研究

本文介绍了木粉种类和含量对再生PE和PP挤出过程和性能的影响 ,并讨论了木粉预处理对再生料性能的影响因素。     

Target-aimed versus wishful-thinking in designing efficient GHG reduction strategies for a metropolitan city: Taipei

In recent years, many national and local governments claim for a specific GHG (greenhouse gas) reduction goal targeted for many years later. In 2005, the Taipei City government announced that Taipei's total GHG emission in 2015 will reach the same level as that in 2005 and then down to 75% of that level at year 2030. However, based on the estimated energy consumption and GHG emission and the proposed emission reduction plans from the local government, it is clear that these goals are not going to be accomplished.