一种二维微位移平台测量系统的研究

微位移测量已经广泛应用于精密测量领域中,实现微位移测量最关键的环节在于精确的定位和精细的运动.文章设计了一种基于应变方式进行二维微位移(纳米级)测量的系统,详细阐述了该系统主要组成部分:微位移检测传感器、处理电路及相关系统软件.实验结果表明该系统可以满足二维微(纳米级)测量的要求.     

多壁碳纳米管湿敏传感器的研究

传感器的基底为Al板电化学氧化成Al2O3绝缘层模板,上面真空溅射了叉指金电极,在电极之间旋涂微量多壁碳纳米管的水悬浊液,干燥后作为敏感膜.室温下测试传感器暴露在不同湿度的电阻变化,发现吸附了H2O后传感器的导电能力降低,且下降的幅度与被测湿度有良好的梯度关系.同时该多壁碳纳米管再经缩合剂EDC修饰后旋涂于电极上形成的敏感膜对湿度呈指数级变化.对它们的湿敏响应的机理进行了一些初步的探讨.     

偏置条件对NMOS器件X射线总剂量效应的影响

采用10 keV X射线,对NMOSFET在不同偏置条件下进行总剂量辐射,分析了辐照前后辐射感生的氧化物陷阱电荷与界面态电荷对MOS器件阈值电压的影响以及辐射导致漏电现象.实验结果表明,对于NMOSFET,On偏置条件是最劣偏置条件,Off偏置条件是最优偏置条件.     

卷烟信息网络防伪系统的构建及应用

介绍了卷烟信息网络防伪管理系统构建原理、技术特点和功能 ,及其在烟草行业中的应用。     

Mechanical properties of compacts and particles that control tableting success

At their first sucking contact, neonates prefer an unwashed breast to a washed one, but an amniotic fluid (AF)- treated breast over a "natural odour" breast. We examined the development of these neonatal olfactory preferences. On days 3-4 significantly more babies still selected their mother's unwashed breast (n = 21) than the washed alternative (n = 8). Preferences for natural breast odours were more pronounced for girls than boys. In a subsequent experiment comprising another 28 babies, the number of babies who selected a naturally scented (n = 9) vs an AF-treated breast (n = 19) on days 2-5 were not reliably different. However, babies who selected the natural breast had longer pre-test maternal contact and had spent more time breastfeeding. Ten babies who chose the AF breast in the latter experiment were tested in the same manner several days later; all preferred the naturally smelling breast. While preferences for AF fade after birth, responsiveness to natural breast odours may be enhanced by postnatal experience.     

Evaluation of enzyme-linked immunosorbent assay for the diagnosis of Helicobacter pylori infection in children from different age groups with and without duodenal ulcer

BACKGROUND: Myocardial ischemia induced by 5-fluorouracil (5-FU) is a relatively rare, but potentially serious, occurrence. Some case reports have indicated that recurrent ischemia may be prevented if 5-FU is resumed after pretreatment with antianginal therapy. METHODS: A 54-year old woman was diagnosed with stage IIA squamous cell carcinoma of the anus. Treatment with concurrent radiation and chemotherapy (mitomycin-C and 5-FU) was initiated with curative intent. RESULTS: The patient had no evidence of underlying coronary artery disease based on history, physical examination or ECG. Approximately 48 h after initiation of 5-FU infusion the patient developed anginal pain associated with ECG changes compatible with ischemia. After resolution of ischemia and ruling out of myocardial infarction, coronary arteriography demonstrated normal coronary arteries. In an attempt to prevent myocardial ischemia, calcium channel blocker and nitrate therapy was started, but anginal pain with ECG change recurred when 5-FU was resumed. This necessitated selection of an alternative chemotherapy regimen. CONCLUSIONS: Even in the presence of normal coronary arteries, antianginal therapy may not preclude the occurrence of potentially serious 5-FU induced myocardial ischemia. For patients who experience 5-FU-induced myocardial ischemia, development of alternative chemotherapy regimens should be considered.     

单一失效机理引起的元器件贮存寿命评价方法研究

电子元器件长期贮存过程发生的失效是由多种失效机理共同作用的结果．以器件贮存寿命整体为基础的寿命评价难度很大。选择对器件贮存寿命影响最大的单一失效机理．以失效物理为基础．通过高加速应力试验进行寿命评价研究,获得的寿命可以较准确地反映器件真实的贮存寿命。单一失效机理贮存寿命的研究是元器件贮存可靠性工作的重要内容。     

点阴极电场辅助阳极连接中的紧密接触面积和电流

用等效电路的方法研究了点阴极情况下的电场辅助阳极连接效应，计算了连接电流，连接孕育期和紧密接触面积，本文结果表明，连接初期电流迅速衰减，随后缓慢变小，直至某一稳定值，孕育期随温度上升指数下降，连接温度高时，孕育期将难以观察到；待连接表面之间紧密接触面积随时间延长而非线性扩展，紧密接触区域增大时，其边界向外推进速度渐小，而接触面积增加渐快。     

基于自相关降噪的混叠转子振动信号分离

航空发动机在运行过程中,传感器测得的振动信号是各振源的混叠信号,且含有很强的噪声。常规的信号处理方法难以分离混叠信号,对机器的健康监测和故障诊断造成了很大的困难。介绍了盲源分离基本原理和方法,指出盲源分离算法在强噪声环境下失效。针对强噪声环境下的混叠振动信号,提出首先通过时延自相关降噪方法对振动信号进行降噪,然后通过盲源分离算法对降噪后的信号分离。仿真结果验证了提出方法的有效性。最后,利用该方法对实测混叠转子振动信号成功实现了降噪和盲分离,为噪声环境下的混叠信号分离提供了一种新的方法。