A Digitally Controlled Stimulator for Neurophysiological Applications

A stimulator circuit is presented which is capable of generating pulse train waveforms suitable for neurophysiological experiments are available, as well as special test conditions such as dishabituation. Digital and linear integrated circuits are used to provide precise control over the stimulus parameters.     

Integrated plasma-aided nanofabrication facility: Operation, parameters, and assembly of quantum structures and functional nanomaterials

The development, operation, and applications of two configurations of an integrated plasma-aided nanofabrication facility (IPANF) comprising low-frequency inductively coupled plasma-assisted, low-pressure, multiple-target RF magnetron sputtering plasma source, are reported. The two configurations of the plasma source have different arrangements of the RF inductive coil: a conventional external flat spiral “pancake” coil and an in-house developed internal antenna comprising two orthogonal RF current sheets. The internal antenna configuration generates a “unidirectional” RF current that deeply penetrates into the plasma bulk and results in an excellent uniformity of the plasma over large areas and volumes. The IPANF has been employed for various applications, including low-temperature plasma-enhanced chemical vapor deposition of vertically aligned single-crystalline carbon nanotips, growth of ultra-high aspect ratio semiconductor nanowires, assembly of optoelectronically important Si, SiC, and Al_1-xIn_xN quantum dots, and plasma-based synthesis of bioactive hydroxyapatite for orthopedic implants.     

时间分解光谱技术在钢铁分析中的应用

研究了单火花光谱在不同采样时间段分析灵敏度与窗口的关系,P、S、Al、Ni、Ti、B、Mg、Sb、Pb、As、Bi、Ta、Sn应用TRS技术检出限明显降低,而C、Si、Mn、Cr、Mo、V、W、Co、Nb则不显著;合适的采样窗口能提高Sb的分析准确度,Mg则可减少背景波动带来的影响,Cu可扩大分析线性范围;采用TRS技术在诸有效元素中分析灵敏度可提高1.36～5.00倍,能更好地满足品种钢的研究开发与生产检验的需求.     

数字多用表的比例功能在电阻箱检测中的应用

本文提出了检测电阻箱的一种新方法--比例法.文章除介绍其原理和方法外,还对装置的不确定度进行了分析,并对比例法检测数据和数表法直接测量的检定结果进行比对.比例法检测电阻箱的特点是对标准器和辅助设备的要求低、工作效率高并可实现半自动检定.拥有数字多用表和标准电阻的检测部门可利用本方法.     

Description of Structural Damage Caused by the Terrorist Attack on the Pentagon

On September 11, 2001, an airliner was intentionally crashed into the Pentagon. It struck at the first elevated slab on the west wall, and slid approximately 310?ft (94.5?m) diagonally into the building. The force of the collision demolished numerous columns and the fa?ade of the exterior wall, and induced damage to first-floor columns and the first elevated slab over an area approximately 90?ft (27.4?m) wide and 310?ft (94.5?m) long. None of the building collapsed immediately. The portion that remained standing, even after an intense fire, sustained substantial damage at the first-floor level.     

Omnibus Hypothesis Testing in Dominance-Based Ordinal Multiple Regression.

Often quantitative data in the social sciences have only ordinal justification. Problems of interpretation can arise when least squares multiple regression (LSMR) is used with ordinal data. Two ordinal alternatives are discussed, dominance-based ordinal multiple regression (DOMR) and proportional odds multiple regression. The Q2 statistic is introduced for testing the omnibus null hypothesis in DOMR. A simulation study is discussed that examines the actual Type I error rate and power of Q2 in comparison to the LSMR omnibus F test under normality and non-normality. Results suggest that Q2 has favorable sampling properties as long as the sample size-to-predictors ratio is not too small, and Q2 can be a good alternative to the omnibus F test when the response variable is non-normal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

粘弹材料复弹性模量的全频段表征与测量

1引言 声学上常用的吸声材料多为高阻尼的有机材料,这类材料在力学性能上表现为恒应力加载下的蠕变行为和恒应变加载下的应力松弛行为,在声学性能上表现为材料响应比激励明显滞后,即损耗角较大,并且材料的性质强烈依赖于激励频率.     

CT-6B托卡马克的交流运行实验研究

在CT—6B托卡马克上首次实现了多周期交流运行，对多个周期中等离子体进行比较发现，尽管在每个周期的两个半周中等离子体与壁的相互作用有所不同，但等离子体中的杂质积累并未受到严重影响。通过内磁探针测量了等离子体电流密度的分布，发现等离子体电流首先从弱场区开始反相，电流反相过零时同时存在正负局部等离子体电流，此时的磁面结构有效地约束了粒子。     

Plasma Induced Degradation of Benzidine in Aqueous Solution

The degradation of benzidine in aqueous solution by the low temperature plasma was examined. The results showed that the concentration of medium and the value of pH have an appreciable effect on the degradation of benzidine. What is more important is that iron ions acting as a catalyst play an important role in this reaction. For exploring the degradation mechanism of benzidine, some of the intermediate products were recorded by HPLC (high performance liquid chromatography).     

ATM/SDH接口的管理:CLR QoS的在线监测

通信网的管理对服务质量至关重要。在实际的网络中,需要对各个子网和网络单元进行良好的管理和控制。 文章从系统的角度分析了ATM/SDH接口的管理,并着重讨论了CLR QoS在线监测问题。