Convergence and attractivity of memristor-based cellular neural networks with time delays

This paper presents theoretical results on the convergence and attractivity of memristor-based cellular neural networks (MCNNs) with time delays. Based on a realistic memristor model, an MCNN is modeled using a differential inclusion. The essential boundedness of its global solutions is proven. The state of MCNNs is further proven to be convergent to a critical-point set located in saturated region of the activation function, when the initial state locates in a saturated region. It is shown that the state convergence time period is finite and can be quantitatively estimated using given parameters. Furthermore, the positive invariance and attractivity of state in non-saturated regions are also proven. The simulation results of several numerical examples are provided to substantiate the results.     

Thickness effects of a carbon-supported platinum catalyst layer on the electrochemical reduction of oxygen in sulfuric acid solution

The influence of the thickness of a carbon-supported platinum catalyst layer on the oxygen reduction reaction (orr) has been studied in sulfuric acid solution by means of a thin-film rotating disk electrode. Pronounced changes in the Pt utilization, electrode activity and the orr kinetics have been observed upon varying the catalyst layer thickness. The thicker film electrode exhibits a higher Pt utilization efficiency and higher activity, and promotes the orr kinetics at potentials relevant to fuel cell operations. The participation of Pt surfaces not in contact with the electrolyte solution in electrochemical reactions via the spillover of adsorbed hydrogen and oxygen species, is proposed to be responsible for the changes. The thicker catalyst layer is likely to modify the Pt particle–particle distance by providing shared Pt sites between adjacent carbon supports, to improve the surface density of active catalyst particles per single carbon support by sharing adjacent catalyst sites, and to increase the ratio of the particle surfaces free of blocking anions to the catalyst|electrolyte interface surfaces. The carbon-supported platinum catalyst layer becomes active at 0.90 V vs RHE only when the catalyst layer is thicker than 1 μm. To provide reasonable activity, the minimum catalyst layer thickness should be around 2–4 μm. These results should be considered in the design of the cathode catalyst layer of polymer electrolyte membrane fuel cells.     

帕罗西汀治疗广泛焦虑症的疗效分析

目的 观察帕罗西汀对广泛焦虑症的临床疗效和副反应。方法 对60例临床诊断为广泛焦虑症的住院病人服用帕罗西汀治疗4周。采用汉密尔顿焦虑量表(HAMA)评价其疗效，不良反应症状量表(TESS)评价其副反应。结果 帕罗西汀治疗广泛焦虑症的有效率为86．7％，痊愈率为63．3％，副反应较轻。结论 帕罗西汀对广泛焦虑症治疗安全而有效，尤其适用于老年人。     

长骨内开口效应对其力学性能影响的理论模型研究

建立一个股骨中段的外侧皮质带有矩形开口的力学模型,采用有限元方法,计算骨开口区的尺寸改变时,股骨的扭转刚度和应力分布的变化。结果表明:骨开口长度为骨外径的1倍时(1OD),对股骨扭转刚度和剪应力分布的影响较小;开口长度从2OD增至4OD时扭转刚度急剧减小,而且剪应力的最大值位于开口区中心。本结论对临床骨科的手术治疗方法和骨开口尺寸的控制提供了重要的理论依据。     

一种基于EEG特征提取的癫痫棘波综合检测判决方法

癫痫特征的自动检测在临床应用上具有重要的意义。本研究综合小波变换、非线性能量算子、特征提取和神经网络等技术，提出了一种癫痫棘波检测系统，充分发挥各技术的优点，在对真实脑电数据的处理中，表现出良好的性能。     

数值模拟鼻甲的切除对鼻腔内气体流场的影响

量化研究鼻腔结构的变化对鼻腔内气体流场分布的影响.通过CT图像对鼻腔结构进行三维重建并用有限元方法对气体流场进行数值分析.对重建的鼻腔模型的一侧,分别去掉部分中鼻甲和部分下鼻甲并用有限元方法再次进行数值分析,将得到的结果与原始模型进行比较.观察气体流场分布的变化,在两侧鼻腔的流量分布均有变化,在去掉部分鼻甲的一侧流场和气压的分布也有所改变.通过数值模拟,我们量化的显示了鼻腔结构的变化对鼻腔内气体流场分布的影响.     

液体表面张力系数及测量精度的分析

分子之间的相互作用产生分子力,阐述表面张力形成的基本原理。对表面张力系数的测量进行分析,讨论提高测量精度的方法。     

CA_(15-3)对术后乳腺癌的随诊价值

目的：探讨 Ｃ Ａ１５ － ３ 对术后乳腺癌的随诊价值。材料与方法：１９９６ 年６ 月至１９９６ 年１２ 月行常规放疗的术后乳腺癌患者４５ 例,于放疗前开始首次检测外周血 Ｃ Ａ１５ － ３ 值,在以后的随诊工作中,作为检查项目之一,即每１～３ 个月查血１ 次,监测时间为２ 年。结果：有复发转移与无复发转移两组的 Ｃ Ａ１５ － ３ 水平分别为（５６ ．２１ ±８ ．３７） Ｕ／ｍｌ,（１３ ．４９ ±２ ．２２） Ｕ／ｍｌ, Ｐ＜ ０ ．０１ ; Ｃ Ａ１５ － ３ 升高的５ 例复发转移患者, Ｃ Ａ１５ － ３ 首次升高均出现于临床或影像学检查之前,提早时间平均为（２ ．５４ ±１ ．３６） 个月;以 Ｃ Ａ１５ － ３ ＞ ３０ Ｕ／ ｍｌ 为阳性,６ 例复发、转移患者中,５ 例阳性,阳性率的９５ ％ 可信区间为３６ ％ ～１００ ％ ,３９ 例无复发、转移患者中,１ 例 Ｃ Ａ１５ － ３ 阳性,假阳性率的９５ ％ 可信区间为０ ～１４ ％ 。结论： Ｃ Ａ１５ － ３ 对乳腺癌术后的转移或复发有较好的特异性和阳性预测性,在术后随诊中有不可替代的预测作用。