基于过程神经网络和量子遗传算法的油藏采收率参量逆向求解

对于多输入多输出系统，针对如何根据系统模型和期望输出反求系统输入的问题，提出了一种基于过程神经网络和量子遗传算法相结合的方法，并给出了具体的实现方法。首先根据实际系统的领域知识和学习样本集，建立满足系统实际输入输出映射关系的正向过程神经网络；然后按照系统在过程区间的某一期望输出，用过程神经网络的输出误差构造适应度函数，用量子遗传算法逆向确定系统的过程输入信号，使该输入信号满足已建立的正向过程映射关系，从而完成系统的逆向过程控制。油藏采收率参量的逆向求解结果证明了该方法的有效性。     

用神经网络建立台阶爆破块度的预测

应用神经网络建立爆破系统的输入和输出非线性图形系统是很有效的。当建立神经网络系统时 ,输入端应当数量少一些 ,因此 ,本文采用爆破性分级指数和炸药单耗作为神经网络的输入端 ;岩石块度的分形维数作为神经网络的输出端     

电喷汽油机故障码的设置条件

针对电喷汽油机故障码的设置条件，开发研制了电控发动机故障模拟试验台，进行了发动机原机性能试验、传感器通断试验、传感器输出信号衰减和通断率影响试验。通过对与电控单元（ECU）输入信号有关的空气流量传感器、爆震传感器、冷却液温度传感器和转速传感器故障的模拟和再现，研究了发动机的各种故障现象、运行状况和性能。结果表明：空气流量传感器断开、输出信号衰减和通断率对发动机运转和性能的影响不同，虽然显示的故障码相同，但故障现象不同，对发动机运行状况的影响也不同；断开爆震传感器或冷却液温度传感器信号，显示的故障码为事实码；转速传感器输出信号衰减与断开信号的情况相比，虽然出现故障的部件相同，但故障码显示状态却不同。     

反激式变换器的电磁干扰分析

应用频域分析方法，对给定输入、输出电压及输出电流，并工作于临界连续模式下的反激式变换器进行分析。着重分析了占空比变化对输入电流、输出电流、开关管压降及交变磁通谐波的影响，为在产品的设计阶段尽可能减小电磁干扰信号提供了理论依据。     

用动态补偿器实现稳定的抗干扰

前言对一个给定的控制系统,除控制者能任意改变的输入外,往往还有控制者不能改变的或者不能完全改变的一些其它输入,如伺伺机构中的参考输入,附加振荡器屏蔽不严而传给主系统内部的信号以及其它干扰信号等等。这些信号都从系统的外部进入系统,所以叫做“外干扰”。对受外干扰作用的系统,能否引进某种型形的反馈,使被调输出     

常压塔汽油干点观测方法研究

提出了一种基于系统机理方程的常压塔汽油干点神经网络观测方法，其步骤是：首先建立系统的机理方程，并基于此方程构造观测器观测出常压塔一些不可测量但可观测的量；然后将观测量与可测量一起作为输入信号，将汽油干点作为输出信号构成神经网络观测汽油干点，与实际化验值对比，汽油干点误差的绝对值在2℃以内，表明这一观测方法有较高的精度。     

精确消除衰减直流分量误差的改进算法

传统全周傅氏算法在直接处理含有指数衰减直流分量的电力系统故障信号时会产生较大误差,针对这个问题,提出了消除其误差的改进傅氏算法.该算法基于包含衰减分量的输入信号在一个周期内积分值及采样数据的求和不为零的原理,在计算衰减分量误差的过程中不需要增加采样点和任何近似计算,就可以求出衰减直流分量对傅氏算法带来的误差及衰减参数,将衰减分量造成的误差从故障输入信号的傅氏算法结果值中减去.仿真结果表明,该算法可以获得精确的基波及各次谐波相关参数,可应用于电力系统谐波在线分析.     

鱼类视神经损伤和再生的研究

综术了鱼类视网膜－顶盖系统的研究概况，包括视网膜、视神经和顶盖的组织结构特点；同时介绍了损伤视神经引起的视网膜神经节细胞的变化及其跨神经元的影响；最后综述了视神经再生与神经传入活性，相邻神经纤维间的相互作用及靶区选择的关系等方面的研究进展。     

锁相环实现取样式A／D转换的原理及电路

本文提出一种利用锁相环实现取样式Ａ／Ｄ转换的新方法，通过锁相环对输入信号进行频率变换，获得一等效延时△ｔ的采样信号；输入信号的等效采样次数及实际采样间隔根据其频率特性由微机编程控制。基于此原理设计出高频周期信号的数据采集系统。     

过采样方法在系统辨识中的应用

为了对带噪输出的控制系统进行盲辨识，提出了一种利用过采样法辨识控制系统函数的方法，通过过采样控制系统的输出信号，将原单输入单输出系统转换成为一个新的与原系统具有相同输出极点的单输入多输出系统，再估计出这个新的单输入多输出系统的传递函数，最后得到原单输入单输出系统的模型参数，仿真结果表明，与常用的高阶矩法相比，该方法具有不受系统结构影响，不需要计算样本数据的高阶统计矩，使用的样本数据量少，便于计算机实现的优点。     

Novel pathway connecting the outer and inner vertebrate retina

In many fish retinas, thin axons from the external horizontal cells extend through the inner nuclear layer and expand into large terminal processes that lie along the border of the inner nuclear and inner plexiform layers. Although the horizontal-cell axon terminals are structurally very prominent, their function is unknown. Here we report morphological and functional evidence that signals from catfish (Ictalurus punctatus) horizontal-cell axon terminals can be transmitted directly to amacrine cells. Current injected into horizontal-cell axon terminals produces responses from both transient and sustained amacrine cells very similar to those elicited by light stimuli. Electron microscope observations show chemical synapses from the axon terminals onto amacrine cell perikarya and processes. These data suggest that amacrine cells in the catfish retina receive two inputs, one from bipolar cells and the other from horizontal-cell axon terminals.     

Bipolar cells in the mudpuppy retina use an excitatory amino acid neurotransmitter

The bipolar cells of the vertebrate retina are the principal neuronal elements which transmit photoreceptor activity from the outer to the inner retina. An important function of the bipolars is to segregate photoreceptor input into independent ON and OFF channels which are subserved, respectively, by the depolarizing and hyperpolarizing bipolar subtypes. Ultrastructural and physiological observations suggest that chemical neurotransmission is the predominant means of bipolar input to the inner retina. Both ON and OFF bipolars apparently release excitatory transmitters. Histological studies with cytotoxic agents and physiological studies indicate that third-order neurones have excitatory amino acid receptors. In ON-OFF amacrine and ganglion cells, which receive input from both bipolars, ON and OFF excitation have a similar ionic basis, suggesting that the same transmitter may be released by both types of bipolars. We have now found that (+/-)cis-2,3-piperidine dicarboxylic acid (PDA), a new excitatory amino acid antagonist, blocks bipolar input to the inner retina and thus suggests that an excitatory amino acid is a bipolar cell transmitter.     

一种适用于高速CMOS传感器的数据传输方法

为了解决高速CMOS图像传感器数据传输问题,采用了一种适合于大数据流量的CameraLink的传输方法。将传感器输出的信号经过FPGA的预处理,然后转换成CameraLink标准的低电压差分信号(LVDS)进行传输,从而进行了高传输率下数据的传输,并介绍了设计过程中的注意事项。     

基于VxWorks平台的MPEG4视频采集压缩系统设计与实现

在列车监控装置中视频信息直观明了地再现列车内情景．VxWorks实时操作系统下视频采集压缩系统涉及到PCI驱动程序的开发、视频采集卡的编程、MPEG4压缩算法的应用、文件管理等．该系统用TMS320DM642实现对视频信号的压缩算法，通过PCI总线送至本地硬盘存储，形成文件，通过地面回放软件进行回放．     

GABA and GAD immunoreactivity of photoreceptor terminals in primate retina

Within the vertebrate retina, two types of photoreceptor cells--the rods and cones--transduce visual signals and convey this information through synapses with bipolar and horizontal cells. Although the neurotransmitter at these first-order synapses has not been identified, electrophysiological studies suggest that it might be excitatory. In the present study, however, we have found photoreceptor terminals in the rhesus monkey retina which are immunoreactive with antibodies to either gamma-aminobutyric acid (GABA) or L-glutamic acid decarboxylase (GAD, an enzyme involved in the synthesis of GABA). In the perifoveal region of the retina, approximately 25% of presynaptic profiles having ultrastructural characteristics of either rod or cone terminals are immunoreactive with one or the other antibody. This evidence for a putatively inhibitory neurotransmitter in photoreceptor terminals challenges present understanding of retinal synaptic function.     

Transmembrane semaphorin signalling controls laminar stratification in the mammalian retina

In the vertebrate retina, establishment of precise synaptic connections among distinct retinal neuron cell types is critical for processing visual information and for accurate visual perception. Retinal ganglion cells (RGCs), amacrine cells and bipolar cells establish stereotypic neurite arborization patterns to form functional neural circuits in the inner plexiform layer (IPL), a laminar region that is conventionally divided into five major parallel sublaminae. However, the molecular mechanisms governing distinct retinal subtype targeting to specific sublaminae within the IPL remain to be elucidated. Here we show that the transmembrane semaphorin Sema6A signals through its receptor PlexinA4 (PlexA4) to control lamina-specific neuronal stratification in the mouse retina. Expression analyses demonstrate that Sema6A and PlexA4 proteins are expressed in a complementary fashion in the developing retina: Sema6A in most ON sublaminae and PlexA4 in OFF sublaminae of the IPL. Mice with null mutations in PlexA4 or Sema6A exhibit severe defects in stereotypic lamina-specific neurite arborization of tyrosine hydroxylase (TH)-expressing dopaminergic amacrine cells, intrinsically photosensitive RGCs (ipRGCs) and calbindin-positive cells in the IPL. Sema6A and PlexA4 genetically interact in vivo for the regulation of dopaminergic amacrine cell laminar targeting. Therefore, neuronal targeting to subdivisions of the IPL in the mammalian retina is directed by repulsive transmembrane guidance cues present on neuronal processes.     

Restoration of vision after transplantation of photoreceptors

Cell transplantation is a potential strategy for treating blindness caused by the loss of photoreceptors. Although transplanted rod-precursor cells are able to migrate into the adult retina and differentiate to acquire the specialized morphological features of mature photoreceptor cells, the fundamental question remains whether transplantation of photoreceptor cells can actually improve vision. Here we provide evidence of functional rod-mediated vision after photoreceptor transplantation in adult Gnat1?/? mice, which lack rod function and are a model of congenital stationary night blindness. We show that transplanted rod precursors form classic triad synaptic connections with second-order bipolar and horizontal cells in the recipient retina. The newly integrated photoreceptor cells are light-responsive with dim-flash kinetics similar to adult wild-type photoreceptors. By using intrinsic imaging under scotopic conditions we demonstrate that visual signals generated by transplanted rods are projected to higher visual areas, including V1. Moreover, these cells are capable of driving optokinetic head tracking and visually guided behaviour in the Gnat1?/? mouse under scotopic conditions. Together, these results demonstrate the feasibility of photoreceptor transplantation as a therapeutic strategy for restoring vision after retinal degeneration.     

GAP-43在锦鲤荒漠沙蜥和雉鸡视网膜内分布的免疫组化研究

GAP-43具有多种功能,主要与神经元轴突的生长、再生、神经递质的释放及膜泡的吞噬有关.本研究用免疫组织化学的方法观察了正常成年锦鲤、荒漠沙蜥和雉鸡视网膜内GAP-43分布.结果显示GAP-43主要分布在内网层,另外,在内核层、外网层、光感受器细胞层因动物不同也呈现不同的分布特点,而在节细胞层中3种动物均未发现GAP-43阳性染色.在锦鲤视网膜中GAP-43主要分布在内网层和内核层的无长突细胞;在荒漠沙蜥视网膜中GAP-43主要分布在内网层和外网层,在雉鸡视网膜中GAP-43主要分布在内网层、外网层、外核层和光感受器外节,其中在雉鸡视网膜外核层和光感受器外节中发现阳性分布是在脊椎动物此层发现GAP-43的首次报道.     

Horizontal cell synapses onto glycine-accumulating interplexiform cells

Horizontal cells mediate lateral transmission of signals in the outer plexiform layer of the vertebrate retina, and are presumed to contribute to surround properties of photoreceptors and bipolar cells by chemical transmission. The cell bodies and dendrites of fish horizontal cells possess presynaptic specializations characteristic of conventional chemical synapses. Horizontal cell axon terminals have not so far been shown to contain presynaptic specializations nor have the targets of the somatic and dendritic synapses been fully characterized. Using electron microscope autoradiography of retinas labelled by high-affinity 3H-glycine uptake, we show here that goldfish horizontal cells make somatodendritic and axodendritic synapses on glycinergic interplexiform cells (Gly-IPCs) as apposed to dopaminergic interplexiform cells. Thus, horizontal cells have at least three postsynaptic targets: photoreceptors, bipolar cells and Gly-IPCs. Gly-IPCs may constitute a major alternative pathway for horizontal cell signals to reach the inner plexiform layer.     

高于胶凝临界温度直链淀粉分子分形

应用动态光散射技术,研究直链淀淀粉水溶液在高于胶凝临界温度条件下驰豫谱化的规律,发现动态光散射驰豫谱经历了指数衰减及随后的非指数衰减（慢模）两种模式,对于快模,可用大分子链串滴运动解释,对于慢模,则可用分形构象下的反常扩散加以解释。此外,还测量了直链淀粉水溶液在不同温度、不同浓度下的分维,发现直链淀粉分子符合自避无规行走模型,分维等于１．６７,且随样品浓度、温度的变化而略有变化。