Organic field-effect transistor with extended indium tin oxide gate structure for selective pH sensing

In this study, organic field-effect transistors (OFETs) with extended gate structure were fabricated for selective pH sensing applications. Indium tin oxide (ITO) was used as extended gate electrode as well as an active layer for H⁺ sensing. The threshold voltage of the fabricated ion-selective OFET was varied by the changes in the electrochemical potential at the ITO electrode surface upon its exposure to buffer solutions with variable pH values. The sensor showed excellent linearity and a high sensitivity of 57–59 mV/pH in the pH range of 2–12. The selectivity of the ITO sensing layer to H⁺ ions was also investigated by measuring the interfering effect of Ca²⁺ and K⁺ ions in the buffer pH solutions. The results showed that the Ca²⁺ and K⁺ ions weakly interfere with the selective pH sensing of the ITO-extended gate OFET sensor device.     

一种平滑的可变步长算法

本文从长时相关性(LRD)和突发性两个方面,阐明图像组(GOP)时间尺度上的流量能够体现原有视频帧序列的流量特性。并在固定步长自适应算法(FSSA)和可变步长自适应算法(VSSA)的基础上提出了一种新的平滑的可变步长自适应算法(S-VSSA),这种算法可以在GOP所表示的大时间尺度上预测MPEG-4视频流量。仿真实验结果显示:该算法收敛速度快,预测误差低,可以明显改善预测性能。     

空芯带隙型光子晶体光纤残余双折射特性研究

采用磁控溅射法, 在玻璃基底上一步沉积In₂S₃薄膜。研究了溅射功率对In₂S₃薄膜的成分、结构、表面形貌和光电性能的影响。结果表明: 所制备的所有薄膜均为β-In₂S₃, 无杂相存在, 且具有(222)面择优生长特性。溅射功率对薄膜的成分、厚度和结晶度具有明显的影响, 并因此影响薄膜的光学和电学性能。薄膜在100W沉积时最接近化学计量比, 薄膜的透过率随着溅射功率增大在500nm波段附近显著提高, 禁带宽度达到2.45eV, 同时电流密度增大两个数量级。     

利用基于导数更新的双基机载雷达杂波距离依赖性补偿方法

该文提出了两种利用基于导数更新(DBU)的双基机载雷达杂波距离依赖性补偿新方法,分别以接收载机方向图主瓣方向的接收斜距和接收载机方向图主瓣方向的接收俯仰角余弦为更新变量,利用该方法对回波数据进行补偿后,能够有效降低双基机载雷达杂波的距离依赖性,进而大大提高空时自适应处理 (STAP)的地面动目标检测(GMTI )性能。仿真数据处理结果证明了所提方法的有效性。     

制氢装置酸性水汽提不合格原因分析及解决措施

对制氢装置酸性水汽提塔汽提效果不佳的原因进行了详细分析,先通过调整汽提塔汽提蒸汽用量,凝结水pH变化不大;后通过改造变换气冷凝流程,凝结水pH满足了回用水指标,回用了大量的水资源,减少了对下游设备的腐蚀;技术改造成本为一次性投入115万元,可创造392.44万元?a的经济效益。     

Ozonation of Sulfur-Containing Aliphatic Compounds in Aqueous Solution. I

In view of the possible reaction of ozone with sulfur containing natural and anthropogenic compounds, the oxidation products of sulfur-containing aliphatic model compounds in pure water in dependence on pH value were investigated.

In the first part, as a model compound for thioether, thiodiglycolic acid was investigated. The rate of elimination is independent of pH-value. At pH 3 as primary product thionyldiglycolic acid is formed, which undergoes further oxidation, but very slowly, to sulfonediacetic acid, which is very stable against ozone attack at pH 3. At pH 7 and higher, however, thionyldiglycolic acid is oxidized faster to sulfonediacetic acid, and this compound is oxidized to sulfoacetic acid, oxalic acid, glyoxylic acid, sulfateion, and CO₂ after longer reaction times. In all cases, sulfite as an inorganic intermediate product could not be identified. Also the intermediate products in pure solutions are ozonized. The mass balances show that 90 to 95% of the oxidation products could be identified. Based on these results, reaction schemes are discussed.     

Effects of maturation and storage on solubility,emulsion stability and gelation properties of isolated soy proteins

Solubility, emulsion stability and gelation of isolated soy proteins and their 7S and 11S fractions from three stages of seed maturity were studied. The pH-solubility profile was similar irrespective of maturation and six-month storage. The 11S protein was more soluble in the acidic pH range than the 7S protein. Oil-in-water emulsion stability of isolated soy protein from mature soybeans was higher than that from the immature ones. This is due to the fact that there was more 7S fraction in the mature soybeans, and 7S protein was found to form a more stable emulsion than that formed from 11S protein. The result suggests that isolated soy protein from mature soybeans would serve as a better emulsifying agent. Heat-induced soy protein gels became weaker as the soybeans became more mature. This can be attributed to the higher content in the immature soybeans of 11S fraction which gives a stronger gel than 7S fraction in the protein from immature soybeans.     

基于相关性的人机系统可靠性模型

本文在剖析人机系统中操作者行为特征的基础上,考虑到操作者行为的自适应性、自学习能力及其行为形成主因子,着重结合操作者行为的相关性-感知作用于判断决策后影响到动作,建立了人机系统中操作者行为模式,并推导出计算操作者可靠度的公式,求出了相应参数.最后进行了实例量度,同时定量辨识了行为相关性对人可靠性的制约程度,以期从人机系统可靠性角度为人机系统的优化设计提供新的依据.     

主要环境因子对两株松树外生菌根真菌生长的影响

研究了培养基、pH、温度及水势对松林下常见外生菌根真菌牛肝菌(Boletus sp.)和乳菇(Lactariussp.)生长的影响。结果表明,在所选择的培养基上,两种菌株都能生长,在添加维生素类物质的天然培养基上,生长旺盛;对pH适应范围较广;L.sp.在弱碱性条件下生长较好,而B.sp.在弱酸性条件下生长较好;温度对菌株生长影响较大,两种菌株最适生长温度均为25℃;极端水势条件下,L.sp.和B sp.均不能生长,轻度水分胁迫能促进L.sp.和B.sp.的生长。L.sp.是一种适应性较强的菌株。     

pH传感器温度补偿模型研究

水质pH值在线监测对提高水产品健康养殖至关重要,本文将无线传感器网络与pH值传感器相集成,设计了pH值监测的无线传感器网络系统。为克服pH值测量过程中温度对测量结果的影响,提出了一种pH传感器温度补偿模型,该模型通过pH传感器和PT100铂电阻温度传感器分别测量溶液的pH值和温度,利用最小二乘法对pH值和电压进行线性分析,建立pH传感器的温度补偿模型。实验结果表明,该补偿模型测量精度高,能够实现较精确的pH值在线监测。