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关键词： 脑放射性药物   放射性药物   NS类配体   Tc标记配合  

关键词： 人工神经网络   化学计量学   偏最小二乘法   脉冲极谱法  

摘要： 将人工神经网络（ＡＮＮ）用于脉冲极谱法中Ｐｂ（Ⅱ）和Ｔ１（Ⅰ）重叠信号峰的解析，对神经网络参数的影响及优化作了研究。结果表明，网络的增益、学习速率和动量是影响网络收敛和稳定性的关键参数。本文还将神经网络与偏最小二乘法的计算结果作了比较。

关键词： 脑型疟   金仓鼠   大鼠   小鼠   模型  

摘要： 本文对脑型疟病理的研究进程进行了一简要的回顾，系统地介绍了用于脑型疟研究的鼠疟原虫金仓鼠。

关键词： 神经元   随机过程   神经网络   建模  

摘要： 生物神经系统是一种脉冲发放神经网络系统。当前流行的人工神经网络模型与生物神经系统相比仍存在着较大差异。本文根据电生理学结果建立了适合于工程应用的脉冲发放神经网络模型。给出了输入－输出关系、突触联接关系、动态方程和学习功力学以及各种统计量的均值和方差。

关键词： .Machine Concept   analog variables   VRP  

摘要： Neural networks can reach their true potential only when they are implemented in hardware as massively parallel processors, This paper presents the random-pulse machine concept and shows how it can be used for the modular design of neural networks, Random-pulse machines deal with analog variables represented by the mean rate of random-pulse streams and use simple digital technology to perform arithmetic and logic operations, This concept presents a good tradeoff between the electronic circuit complexity and the computational accuracy, The resulting neural network architecture has a high packing density and is well suited for very large-scale integration (VLSI), Simulation results illustrate the performance of the basic elements of a random-pulse neuron.

关键词： 除草剂   桉树脑   环庚草醚   合成  

摘要： α－蒎烯与硫酸反应，给出１，４－桉树脑。再与锂、１，３－丙二胺反应，得萜品－４－醇，再气化后，与α－甲基氯苄反应得到环庚草醚。

关键词： [S-35]GTP gamma S autoradiography   nociceptin   orphanin FQ   opioid receptors  

摘要： RECENT reports have identified an endogenous peptide ligand for the opioid receptor-like (ORL1) receptor. In study, ORL1 peptide-stimulated [S-35]GTP gamma S was assessed in rat cortical membranes and brain sections to localize ORL1 receptor-activated G-proteins. In membrane assays, with 20 mu M GDP, ORL1 peptide stimulated [S-35]GTP gamma S binding by approximately two-fold with an ED(50) value of 20 nM. ORL1 peptide-stimulated [S-35]GTP gamma S binding was unaffected by opioid or other G-protein-coupled receptor antagonists. In brain sections, ORL1 peptide-stimulated [S-35]GTP gamma S binding was identified in regions including cortex, amygdala, hypothalamus, thalamus and brain stem. The anatomical distribution of ORL1 peptide-stimulated [S-35]GTP gamma S binding suggests its involvement in cognition, emotion and homeostasis.

关键词： 电力系统   神经网络   非线性控制   正交函数   鲁棒性   逆系统法  

摘要： 本文研究电力系统的运行与控制问题，主要分两大部分：一是关于电力系统运行问题，包括：1．基于函数链网络（FLN）的极限切除时间（CCT）估计;2．人工神经网络（ANN）用于三相短路电流特征值估计，如冲击电路、等效系数及热效应等;3．混合ANN和Lagrange松弛法用于解机组最优投入问题，并针对BP算法不足，利用一种不用精确搜索的共扼梯度训练算法，加速了网络的收敛。二是关于电力系统控制，包括：1．提出高阶FLN和广义逆（GI）学习算法，用于电力系统稳定器（PSS）参数的实时调整;2．逆系统方法用于汽轮机调速汽门控制和发电机励磁控制，对于系统参数的不确定性，采用ANN补偿控制;3．块脉冲函数（BPF）用于PWM系统的分析及最优控制，获得分段恒定解;4．高精度甚低速系统的智能鲁棒控制器设计，有效地克服了直流伺服系统中的低速爬行现象，快速跟踪系统的斜坡输入信号，消除静差，此外，还给出一种使用前向神经网络A／D转换器（ADC）和一种联合使用ANN-ES的电力系统安全性分析及保护控制方案。

关键词： diazepam   fentanyl-induced epileptoid EEG activity   subcortical multineuronal firing   cats  

摘要： Electroencephalographic and clinical signs of epileptoid activity have been associated with the administration offentanyl during surgery in patients. These phenomena have been in turn related to changes in metabolic rate, oxygen consumption, and blood now in specific brain structures both in humans and experimental animals. However, direct evidence showing changes in neuronal firing in specific brain regions during fentanyl-induced epileptoid activity has not been reported. Eight adult male cats with chronically implanted bipolar electrodes in the mesencephalic reticular formation, hippocampus, amygdala, and parieto-occipital cortex were included in the study. Different treatments, i.e., vehicle-fentanyl or diazepam-fentanyl, were administered to the experimental animals at 7-day intervals under neuromuscular blockade and assisted ventilation. Electroencephalographic (EEG) seizures, grouped and isolated spikes, and significant increases of multineuronal activity (MUA) were elicited by fentanyl, 50 mu g/kg iv, in these brain structures. Both EEG and MUA changes reached their maximal values within 6 min of fentanyl administration, and then diminished as time elapsed. Diazepam, 100, 200, or 400 mu g/kg, but not 50 mu g/kg iv, significantly reduced or prevented the fentanyl-induced epileptoid EEG activity and MUA increases. The present results show that both fentanyl- induced epileptoid EEG activity as well as the concomitant increase in MUA of brain subcortical structures are part of the same epileptogenic phenomenon, mainly generated at limbic structures. In addition, the effects of diazepam against both epileptoid EEG activity and increase of MUA of brain subcortical structures support the use of benzodiazepines as premedicants for fentanyl anesthesia in order to prevent or to reduce epileptoid phenomena that can result from opioid administration during the anesthetic procedures.

摘要： In this thesis the development of a hardware artificial neuron device and artificial neural network using stochastic pulse rate encoding principles is considered. After a review of neural network architectures and algorithmic approaches suitable for hardware implementation, a critical review of hardware techniques which have been considered in analogue and digital systems is presented. New results are presented demonstrating the potential of two learning schemes which adapt by the use of a single reinforcement signal. The techniques for computation using stochastic pulse rate encoding are presented and extended with new novel circuits relevant to the hardware implementation of an artificial neural network. The generation of random numbers is the key to the encoding of data into the stochastic pulse rate domain. The formation of random numbers and multiple random bit sequences from a single PRBS generator have been investigated. Two techniques, Simulated Annealing and Genetic Algorithms, have been applied successfully to the problem of optimising the configuration of a PRBS random number generator for the formation of multiple random bit sequences and hence random numbers. A complete hardware design for an artificial neuron using stochastic pulse rate encoded signals has been described, designed, simulated, fabricated and tested before configuration of the device into a network to perform simple test problems. The implementation has shown that the processing elements of the artificial neuron are small and simple, but that there can be a significant overhead for the encoding of information into the stochastic pulse rate domain. The stochastic artificial neuron has the capability of on-line weight adaption. The implementation of reinforcement schemes using the stochastic neuron as a basic element are discussed.