晶体三极管的放大演示实验

晶体三极管的放大演示实验熊晓明（吉林省教育学院长春１３００２２）晶体三极管的放大，是高中物理教学中的难点．一般演示实验都是在一个晶体二极管收音机的基础上，加接在由一个晶体三极管组成的放大器进行一次放大，从而说明晶体三极管有放大作用．由于学生初次接触无...     

A lightweight symmetric image encryption cryptosystem in wavelet domain based on an improved sine map

In the era of big data, the number of images transmitted over the public channel increases exponentially. As a result,it is crucial to devise the efficient and highly secure encryption method to safeguard the sensitive image. In this paper, an improved sine map(ISM) possessing a larger chaotic region, more complex chaotic behavior and greater unpredictability is proposed and extensively tested. Drawing upon the strengths of ISM, we introduce a lightweight symmetric image encryption cryptosystem ...     

响应面法优化多糖类中药材发酵炮制工艺研究

为优化JAXS-2菌株用于多糖类中药材发酵炮制的培养基,在单因素试验基础上,以蔗糖(A)和玉米浆粉(B)的添加量以及发酵温度(C)作为主要影响因子,以发酵炮制液总粗多糖含量(R1)为响应值,通过De-sign Expert 10软件的响应面Box-Behnken试验设计对发酵炮制培养基及发酵参数及其交互作用进行了研究.结果表明:A、B的交互作用对R1影响均达到了极显著水平,C的交互作用不显著.综合考虑原产品对色度的要求和生产成本,确定发酵炮制培养液最佳配方和工艺为:在基础中药材培养液中添加5g/L蔗糖、2g/L玉米浆粉和0.05 g/L的七水硫酸镁,发酵温度为40℃.在该条件下R1为1479 mg/L,与最高预测值1545.4 mg/L比较接近,表明该模型能较好地预测实际发酵情况,可使R1比优化前的1024 mg/L提高44.4％.此外,发酵炮制培养液在制备和高温灭菌过程中,在较短的时间完成了药材的"煎煮"处理,培养液总粗多糖的含量比原常规煎煮法提高了21.7％.     

Temperature Dependence of Electrical Characteristics in Indium-Zinc-Oxide Thin Film Transistors from 10 K to 400 K

The transfer characteristics of amorphous indium-zinc-oxide thin film transistors are measured in the temperature range of 10–400 K. The variation of electrical parameters(threshold voltage, field effect mobility, sub-threshold swing, and leakage current) with decreasing temperature are then extracted and analyzed. Moreover, the dominated carrier transport mechanisms at different temperature regions are investigated. The experimental data show that the carrier transport mechanism may change from trap-limited conduction to variable range hopping conduction at lower temperature. Moreover, the field effect mobilities are also extracted and simulated at various temperatures.     

多糖类中药材发酵炮制菌种的筛选驯化研究

从黄芪、桑葚、枸杞和大枣等4种药材混合匀浆液中定向筛选出了一株可利用这些药材为自身培养基的附生菌,经分子生物学鉴定其与植物乳杆菌(Lactobacillus plantarum)的相似性达98％,为一种可用于食品的安全菌种;经逐步提高多糖类中药材浓度的定向诱导训化,同时对菌种培养基和发酵炮制工艺优化,使其可用于该多糖类中药材的发酵炮制工业化生产.结果表明:采用该菌种发酵炮制,可使发酵炮制液中总粗多糖含量较传统煎煮工艺提高44.1％;该多糖类中药材提取液不但增加了益生菌的有益代谢产物,如多糖类、植物活性肽和有机酸等,且更容易被人的肠道吸收.