Simulation of the development of deformation textures and residual stresses using the Taylor–Bishop–Hill theory

Cold working processes due to inhomogeneous and strong plastic deformations result in the formation of residual stresses and texture within the components. The texture evolution has a strong influence on the residual microstresses and produces non-linear d vs. sin² ψ-curves. The texture evolution and the resulting non-linear d vs. sin² ψ-curves are calculated here using the Taylor–Bishop–Hill theory and an elastic unloading model. Examples are given for the inverse pole figure and non-linear d vs. sin² ψ-distributions due to cold torsion of an austenitic steel.     

压缩冬季直埋光缆线路障碍抢修历时的措施

冬季直埋光缆线路障碍抢修,最困难的问题就是冻土挖掘。本文通过对破碎机、混凝土链锯工作性能的分析,得出了利用破碎机、混凝土链锯进行冻土挖掘可提高冻土挖掘速度,大幅度压缩冬季直埋光缆线路障碍抢修历时的结论。     

多结构互联PCB制作工艺的开发

从普通FR-4板材的树脂体系与固化机理入手,重点研究了混合结构PCB的加工性能,研究凹凸槽、销钉等局部混压定位技术,分析不同材料压合厚度匹配性,实现局部埋入特殊功能子板,且子板与母板的对准度达到小于75？m的要求;同时研究局部混压PCB两种材料之间的蛇形线、孔到两种材料缝隙距离、塞盲孔制作等PCB常用设计,使局部混压结构满足常规PCB制作要求。     

On the mechanisms limiting mobility in InP/InGaAs buried channel nMISFETs

MISFETs incorporating the InP/InGaAs buried channel showed a high peak mobility of 5500 cm²/V s. Spillover of the inversion carriers from the buried channel to the MIS interface on the InP barrier layer caused drastic mobility degradation as the carrier concentration was increased. The spillover was evidenced by observing a negative transconductance and a kink in split capacitance-voltage curves. Remote scattering by the trapped charges at the MIS interface also reduced the mobility when the InP barrier layer was as thin as 2 nm.     

A novel high voltage lateral double diffused metal oxide semiconductor (LDMOS) device with a U-shaped buried oxide feature

A novel U-shape buried oxide lateral double diffused metal oxide semiconductor (LDMOS) is reported in this paper. The proposed structure features ionized charges in both sides of dielectric between source and gate region to enhance the breakdown voltage. The dielectric between drain and drift region affects on the breakdown voltage by adding a new peak in the electric field profile. Two dimensional simulation with a commercial software tool predicts significantly improved performance of the proposed device as compared to conventional LDMOS structures.     

Impact and options for boron diffusions in buried contact solar cells

Boron-diffused rear surfaces are used in place of an Al/Si alloy to form a back surface field (BSF) for single-sided buried contact (SSBC) cells. The findings are that a heavy boron diffusion over a large area can retain high bulk lifetime and have a low saturation current. SSBC solar cells that were made had the entire rear heavily boron diffused. These cells had open-circuit voltages of 650, 645, and 640 mV on 3 and 10 Ω cm p-type, and 100 Ω cm (rear junction) n-type, respectively.     

Pharmacokinetics of progesterone in lactating dairy cows: Gaining some insights into the metabolism from kinetic modeling

Progesterone pharmacokinetics were analyzed for plasma hormone concentrations ranging from linear to saturated metabolism in lactating Holstein cows with differing daily milk yields. The adequacy of 2-coupled first-order (bi-exponential equation), hyperbolic (Michaelis-Menten equation), and sigmoidal (Hill equation) kinetic models to describe the experimental progesterone pharmacokinetic profiles was examined on a statistical basis. After nonlinear regression and statistical analysis of the data-fitting capability, a simple one-compartment model based on Hill equation proved to be most adequate. This model indicates an enzyme-catalyzed metabolism of progesterone involving cooperative substrate-binding sites, resulting from allosteric effects that yield a sigmoidal saturation rate curve. Kinetic parameters were estimated for 2 groups of lactating Holstein cows with different daily milk yields. We found, for the first time, a remarkable quantitative agreement of the Hill coefficient value with that reported in pharmacokinetic studies involving cytochrome P450, family 3, subfamily A (CYP3A)-mediated reactions in other mammals, humans included. It seems that positive cooperativity makes enzymes much more sensitive to plasma progesterone concentration, and their activities can undergo significant changes in a narrow range of concentration as characteristic of sigmoidal behavior. Therefore, the values of classical pharmacokinetic parameters, such as the elimination constant, half-life, and clearance rate, were found to be highly dependent on the plasma progesterone concentration.