Gated three-terminal device architecture to eliminate persistent photoconductivity in oxide semiconductor photosensor arrays

The composition of amorphous oxide semiconductors, which are well known for their optical transparency, can be tailored to enhance their absorption and induce photoconductivity for irradiation with green, and shorter wavelength light. In principle, amorphous oxide semiconductor-based thin-film photoconductors could hence be applied as photosensors. However, their photoconductivity persists for hours after illumination has been removed, which severely degrades the response time and the frame rate of oxide-based sensor arrays. We have solved the problem of persistent photoconductivity (PPC) by developing a gated amorphous oxide semiconductor photo thin-film transistor (photo-TFT) that can provide direct control over the position of the Fermi level in the active layer. Applying a short-duration (10 ns) voltage pulse to these devices induces electron accumulation and accelerates their recombination with ionized oxygen vacancy sites, which are thought to cause PPC. We have integrated these photo-TFTs in a transparent active-matrix photosensor array that can be operated at high frame rates and that has potential applications in contact-free interactive displays. © 2012 Macmillan Publishers Limited. All rights reserved.

Use of contexts in language model interpolation and adaptation

Language models (LMs) are often constructed by building multiple individual component models that are combined using context independent interpolation weights. By tuning these weights, using either perplexity or discriminative approaches, it is possible to adapt LMs to a particular task. This paper investigates the use of context dependent weighting in both interpolation and test-time adaptation of language models. Depending on the previous word contexts, a discrete history weighting function is used to adjust the contribution from each component model. As this dramatically increases the number of parameters to estimate, robust weight estimation schemes are required. Several approaches are described in this paper. The first approach is based on MAP estimation where interpolation weights of lower order contexts are used as smoothing priors. The second approach uses training data to ensure robust estimation of LM interpolation weights. This can also serve as a smoothing prior for MAP adaptation. A normalized perplexity metric is proposed to handle the bias of the standard perplexity criterion to corpus size. A range of schemes to combine weight information obtained from training data and test data hypotheses are also proposed to improve robustness during context dependent LM adaptation. In addition, a minimum Bayes' risk (MBR) based discriminative training scheme is also proposed. An efficient weighted finite state transducer (WFST) decoding algorithm for context dependent interpolation is also presented. The proposed technique was evaluated using a state-of-the-art Mandarin Chinese broadcast speech transcription task. Character error rate (CER) reductions up to 7.3 relative were obtained as well as consistent perplexity improvements. © 2012 Elsevier Ltd. All rights reserved.

4龄中华鲟垂体的EST分析(英文)

表达序列标签(Expressed sequencetag,EST)是鉴定基因表达规律和发现新基因的一种有效的分子生物学手段。为了能在中华鲟(Acipenser sinensis Gray)中发现与生长和生殖内分泌调控相关的基因,我们构建了中华鲟垂体的SMARTcDNA质粒文库。垂体是调节生长和生殖内分泌的重要器官。在本研究中,通过测序筛选得到了944个EST克隆,将所得EST与GenBank数据库中的序列进行比对,结果表明,802(84.96%)个克隆可以找到同源序列,共代表461个基因,其中含132个已

草鱼生长激素在毕赤酵母中的高效分泌表达

为大量获得具有生物学活性的草鱼生长激素 ,对草鱼生长激素cDNA在毕赤酵母中的表达进行了研究。将草鱼生长激素cDNA克隆入毕赤酵母表达载体pGAPZ α B ,构建表达载体pGAPZ α B GH。在三磷酸甘油醛脱氢酶 (GAP)启动子的调控作用下 ,一个类似于天然生长激素大小、分子量约 2 2kD的蛋白获得表达 ,其表达量约 5 0mg L。Western杂交表明 :表达的蛋白与兔抗草鱼生长激素的多克隆抗体特异结合 ,证实该表达蛋白为草鱼生长激素 ;受体夹心式ELISA检测表明 :表达的草鱼生长激素具生

褶纹冠蚌鳃的组织学和扫描电镜观察

利用光镜和扫描电镜研究了雌性褶纹冠蚌外瓣鳃的组织学和形态。结果表明,雌性褶纹冠蚌具一对外瓣鳃。每个外瓣鳃都由内、外二鳃小瓣构成。每片鳃小瓣又由许多纵行排列的鳃丝组成。鳃丝表面具前纤毛、前侧纤毛和侧纤毛,其壁主要由角质层、上皮和基膜组成,内含几丁质棒、鳃腺和血管。相邻鳃丝之间由丝间隔相连。鳃小瓣内的空腔被瓣间隔分隔成许多鳃水管。丝间隔和瓣间隔的壁主要由单层柱状上皮和基膜组成,其内均有血管分布。在繁殖期间辩间隔形态发生变化,将鳃水管分隔成许多小室,形成胚胎发育的孵化室。