APACS353在压缩机控制系统中的应用

介绍ＡＰＡＣＳ３５３智能控制器及其在离心压缩机控制系统中的应用,具体介绍ＡＰＡＣＳ３５３智能控制器特点,压缩机控制系统及系统应用实例等。     

基于FFT的多个空间信号波达方向的估计算法

本文提出了一种与传统算法完全不同的多个空间窄带信号波达方向的估计算法。该算法通过对阵列输出数据的快速傅立叶变换(FFT),建立了FFT频谱与波达方向角的关系;利用这一关系并通过对FFT谱峰的搜索,从而实现了对波达方向的快速估计。计算机模拟实验验证了算法的可行性。     

一种嵌信式微机数据采集系统的实现

主要讨论一个嵌入式微处理机数据采集系统的软／硬件设计方案。     

用Ethernet＋TCP／IP构建现场实时通信网络平台

分析了Ethernet和TCP／IP技术给现场实时通信网络带来的影响,介绍了具有Ethernet网络接口和TCP／IP协议功能的现场智能设备的硬件组成、通令协议层次模型、协议构成和协议数据格式,描述了现场智能设备中发送和接收数据的实现过程。     

秸秆还田对农田生态系统及作物生长的影响

秸秆还用是利用秸秆的一种有效方式．大量试验表明,秸秆还田会对土壤产生多种作用：能改善土壤物理性状,降低土壤容重,增加孔隙度;能增加土壤微生物数量,增强生物和多数酶的活性;增加土壤有机质积累和养分含量;能改变土壤腐殖质组成及特性;影响作物生长发育,促进作物产量提高．其中,秸秆覆盖还田还具有蓄水保墒,调节地温和保持水土,抑制田间杂草等功能．总之,秸秆还田对农田具有良好的生态效应。     

大庆油田聚合物驱油矿场试验动态反映特点

本文对大庆油田聚合物驱油矿场试验中所获得的资料进行了综合分析,揭示了聚合物注入过程中的压力变化规律、聚合物在油层中的流动行为及聚合物驱油效果反映特点,从而深化了对聚合物驱油机理的认识,对今后聚合物驱油方案设计、动态分析及效果评价具有指导作用。     

New oxide phosphors for FEDs: Ruddlesden—Popper phases synthesized with IIIB‐group elements

Abstract— A red‐emitting phosphor, SrTiO³:Pr³⁺, for low‐voltage‐type FEDs and VFDs was developed by Futaba Corporation in 1996. The addition of Al or Ga is essential in the preparation of this phosphor because it improves the luminescence efficiency dramatically. For this impurity effect, Futaba Corporation proposed a charge‐compensation mechanism, which was supported by a recent observation of emission lines due to Al³⁺‐Pr³⁺ pairs. In addition, it was found that Al also works as a scavenger of planar defects, presumably SrO thin layers interleaved in the SrTiO³ lattice, by forming strontium aluminates. The latter mechanism suggests the possibility that a similar impurity effect can be found in materials with crystal structures, including alkaline‐earth oxide layers (Ruddlesden‐Popper phases).     

Array automata and operations on array languages

Array automata acting on scenes (two dimensional tapes) are defined. The set of scenes accepted by array automata are proved to be equivalent to the set of arrays generated by array grammars. Certain operators like substitution, homomorphic replication and insertion are extended to sets of arrays. These operators yield interesting classes of pictures.     

浅析金鸡拦河闸重建工程的环境保护与防治控制

论述了泉州市金鸡拦河闸重建工程的意义,分析了重建工程对河道上下游水生态环境的影响,提出了环境保护与污染防治措施。     

Cognitive processes in complex tasks: introduction and discussion

This paper points out that the fusional limits of binocular stereoscopic viewing are an important factor, not only determining the reproduction range of stereoscopic images, but also the conformity between the stereoscopic display and stereoscopic vision. Experimental results showed that fusional limits increase in proportion to the field of view angle, and that they are affected not only by the size of the viewing target, but also by the effects that the environment has on the target. These findings explain the differences between binocular vision in real space and binocular vision in a stereoscopic display. Finally, the conditions under which observers arc able to view images of stereoscopic displays without excessive visual strain are discussed.