Model for photo-induced long-term drain current transients in GaAs MESFETs

A simple model is presented for the negative drain current transients observed in GaAs MESFETs when subjected to ionizing radiation. The two dominant mechanisms are proposed to be electron trapping under the Schottky gate and in the neutral semi-insulating substrate. The model is suitable for the design and evaluation of radiation-resistant GaAs MESFET integrated circuits using common electrical simulators such as SPICE3.     

合肥电视塔TMD风振控制的响应分析

本文进行了合肥电视塔风振响应分析,探讨了电视塔人体舒适度设计准则。计算表明,电视塔上塔楼的加速度响应大大超出了容许的最大加速度限值。因此,利用塔上60t重的生活、消防用水箱作为调频质量阻尼器(TMD)。通过在频域内大量的TMD参数研究,确定TMD的优化参数。研究结果表明,具有最优参数TMD可以显著提高电视塔的人体舒适度性能,上塔楼的加速度响应下降了49%。在此基础上,本文提出了TMD优化参数的选择路线,结合受控和未控结构的响应比与频率比和TMD阻尼比的关系曲线,采用图解法确定了满足减振要求的TMD优化参数。     

基于频域系统辨识和支持向量机的桥梁状态监测方法

随着大跨度悬索、斜拉桥的增加,保障桥梁安全、降低维护费用成为交通管理以及政府部门关注的问题。针对损伤样本难以获得的实际情况,将桥梁状态监测问题作为模式识别中的“一类学习”问题处理。桥梁模式特征获取过程是“只有输出响应”的系统辨识问题,考虑到监测系统需要在线工作的特点,提出运用概念直观、结果可靠且便于自动实现的CMIF系统辨识方法作为获取模式特征的工具。为了获得足够敏感的异常报警判别函数,采用了基于支持向量机的一类学习算法,这种方法在得到很高灵敏性的同时,可以方便地权衡敏感性和泛化性能之间的矛盾。用香港汀九桥794小时实测数据对所采用的算法进行验证,证明了算法的有效性和实用性,其结果可供设计类似监测系统时参考。     

The direct electrorefining of copper matte

Direct electrorefining of copper matte would be a desirable alternative to copper converting and its associated troublesome sulfur dioxide emissions. After more than 100 years of study, however, no commercial process has been developed, even though an analogous process for the direct electrorefining of nickel matte anodes has been operating successfully for several decades. The unique difficulties associated with copper matte electrorefining are related to the properties of the matte’s decomposition products.     

Analgesic, respiratory and heart rate effects of cannabinoid and opioid agonists in rhesus monkeys: antagonist effects of SR 141716A

This study characterized the antinociceptive, respiratory and heart rate effects of the cannabinoid receptor agonists Delta-9-tetrahydrocannabinol (Delta-9-THC) and WIN 55212 ((R)-(+)-2, 3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]pyrol-[1,2,3-de]-1, 4-benzoxazin-6-yl)(1-naphtalenyl)methanone monomethanesulfonate), N-arachidonyl ethanolamide (anandamide) and the mu and kappa opioid receptor agonists heroin and U69593, alone and in conjunction with a cannabinoid receptor antagonist, SR 141716A [N-(piperidin-1-1-yl)-5-(4-chlorophenyl)-1(2, 4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride] and an opioid receptor antagonist, quadazocine, in rhesus monkeys (Macaca mulatta). Using 12 adult rhesus monkeys, latencies to remove the tail from a 50 degrees C water bath, respiration in 5% CO2 and heart rate were measured. When administered alone, SR 141716A (1.8, 5.6 mg/kg i.m.) did not alter nociception, respiration or heart rate. Delta-9-THC (0.1-10 mg/kg i.m.) and WIN 55212 (0.1-10 mg/kg i.m.) dose-dependently increased antinociception and dose-dependently decreased respiratory minute and tidal volumes and heart rate. These antinociceptive, respiratory and heart rate effects were reversed by SR 141716A but not by the opioid antagonist quadazocine (1 mg/kg i.m.). Anandamide (10 mg/kg i.m.) also produced antinociception. Heroin (0.01-10 mg/kg i.m.) and U69593 (0.01-3.2 mg/kg i.m.) also dose-dependently increased antinociception and decreased respiratory and heart rate measures; these effects were antagonized by quadazocine but not by SR 141716A. These results demonstrate selective and reversible antagonism of cannabinoid behavioral effects by SR 141716A in rhesus monkeys.     

Complex gyrator circuit of 4-port single junction circulator

The adjustment of the 4-port single junction circulator involves a degeneracy between a single impedance pole, a pair of split degenerate poles and one impedance zero. The purpose of this paper is to deduce the real part of the complex gyrator circuit of this device under the assumption that the degenerate relationships between the poles and zeros of the arrangement have been met. This determines the gyrotropy of the ideal device and the adjustment of any matching network.