“至上”与“虚无”

<正>俄国画家马列维奇是"至上主义"抽象绘画流派的创始者,其绘画作品简约而纯粹,以最简单的形式——方块展现出艺术家丰富的感情世界,探索了形体、色彩与空间的关系。而同样善于运用几何形态的西班牙雕塑家奥泰萨的风格则显得冷静而克制,其雕塑作品通常看起来虚幻而抽象,没有强烈的情感表现,以高度理性化的手法展现出一种"虚无"的艺术境界。二人所专注的领域虽有不同,但他们的作品都在关注形式与其所在空间之间的复杂关系。     

用动态规划神经网络模型研究多水库系统的水量分配(下)

为了分析多水库系统中两座水库之间灌溉用水的分配问题，建立了基到动态规划的神经网络模型。为了研究从一座上游水库取水在下游两座之库之间进行水量分配的问题，提出了3个状态变量和4个决策变量的改进的动态规划算法。采用神经网络模型，用3个状态变量动态规划算法得出调度原则，就所研究的多水库系统实例来说，新的动态规划神经网络模型的性能很好，将该模型的性能与临时凑合的标准调度原则和以前推荐使用的约束动态规划神经网络模型进行了比较。     

贵欧泊合成的某些方面

描述了在俄罗斯Dubna应用研究中心合成全硅欧泊的开发研究以及基本步骤. 阐述了这种漂亮的、相对无孔隙的合成欧泊的结构和基本特征以及这种合成欧泊切磨和抛磨的例子.     

Functional penetration of variability of motor neuron spike timing through a modulated neuromuscular system

Variability of the neuronal spike pattern is usually thought of in terms of the information that the different interspike intervals might be encoding. However, the very presence of the variability can have other kinds of functional significance. Here we consider the example of the B15/B16-ARC neuromuscular system of Aplysia, a model system for the study of neuromuscular modulation and control. We show that variability of motor neuron spike timing at the input to the system penetrates throughout the system, affecting all downstream variables including modulator release, modulator concentrations, modulatory actions, and the contraction of the muscle. Furthermore, not only does the variability penetrate through the system, but it is actually instrumental in maintaining its modulation and contractions at a robust, physiological level.     

雷达信号处理中的课题 第一部分:概述和相关处理技术(续)

杂波抑制抑制杂波是许多雷达系统中主要考虑的问题。利用动目标显示(MTI)或脉冲多卜勒(PD)原理就可以实现杂波对消。MTI或PD的设计取决于雷达的特殊性能和所确定的杂波形式。特别重要的是:是否只抑制固定的(零多卜勒)杂波或者还须抑制运动的杂波(云雨、金属箔条)。为了抑制固定的地杂波,有人曾     

电子变压器用的智能功率晶体管

VB348LDIH是用新的纵向功率IC工艺过程设计和制造的,它是一种具有五条引线的PENTAWATT(5瓦)功率器件,非常适用于电子变压器应用,价格也适中。这个IC由一个高压双极型MOS发射极开关功率级、驱动电路系统和保护部件(包括过温和过流关断电路)组成。该IC的主要优点是:过温和过流保护,集成DIAC(二极管交流开关)功能,及寄生参数的变化控制。     

Plasma Discharge Initiation of Explosives in Rock Blasting Application： A Case Study

A plasma discharge initiation system for the explosive volumetric combustion charge was designed, investigated and developed for practical application. Laboratory scale experiments were carried out before conducting the large scale field tests. The resultant explosions gave rise to less noise, insignificant seismic vibrations and good specific explosive consumption for rock blasting. Importantly, the technique was found to be safe and environmentally friendly.     

Influence of Ti Powder Characteristics on Combustion Synthesis of Porous NiTi Alloy

Porous NiTi shape memory alloy (SMA) is a novel biomedical material used for human hard tissue implant .The influence of elemental titanium powder characteristics such as powder morphology, particle size and specific surface area( SSA) on the minimal ignition temperature ,combustion temperature and final product of porous Ni-Ti SMA fabricated by combustion synthesis method was investigated in this paper by scanning electron microscopy (SEM) and laser diffraction.The preliminary data indicated that the titanium powder characteristics had a strong effect on combustion synthesis of porous NiTi SMA.