Uniform Non-Bernoulli Sequences Oriented Locating Method for Reliability-Critical Gates

Hardening reliability-critical gates in a circuit is an important step to improve the circuit reliability at a low cost.However,accurately locating the reliability-critical gates is a key prerequisite for the efficient implementation of the hardening operation.In this paper,a probabilistic-based calculation method developed for locating the reliabilitycritical gates in a circuit is described.The proposed method is based on the generation of input vectors and the sampling of reliability-critical gates using uniform non-Bernoulli sequences,and the criticality of the gate reliability is measured by combining the structure information of the circuit itself.Both the accuracy and the efficiency of the proposed method have been illustrated by various simulations on benchmark circuits.The results show that the proposed method has an efficient performance in locating accuracy and algorithm runtime.

Preparation of erbium ion-doped TiO2 films and the study of their photocatalytic activity under simulated solar light

A series of erbium ion-doped TiO2（Er^3＋-TiO2） films were prepared by a sol-gel dip/spin coating method, and the effect of the dosage of erbium ion（0-2.0 mol%）, the films coating layers（1-5 layers）, and calcination temperature（400-700 ℃） on the film structure and photocatalytic activity were investigated in detail. The films were characterized by means of X-ray diffraction（XRD）, scanning electron microscopy（SEM）, thermal analysis（TG-DTG） and UV-Vis diffusive reflectance spectra（DRS）. The results showed that the films were composed of anatase, and no other TiO2 phases（rutile and brookite）. With the increase of the erbium ion dosage, the crystal size decreased. Erbium ion doping could enhance the thermal stability of TiO2 and inhibit the increase of the crystallite size. Meanwhile doping of erbium ions gave rise to three typical absorption peaks within the range of visible light（400-700 nm）, locating at 490, 523, and 654 nm, attributed to the transition of 4 f electrons. The higher calcination temperature led to higher crystallinity and bigger crystal grains. The photocatalytic performance of the films was evaluated by degradation of methyl orange solution under simulated solar light. The highest quality film we prepared was with 4 layers, 1.0 mol% dosage of erbium ion, and the calcination temperature of 500 ℃. With this film,the degradation percentage of 7.8 mg/L methyl orange solution was up to 53.3% under simulated solar light after 6 h photoreaction.