系统论在医院信息化建设中的应用

医院信息化是一项庞大、复杂的系统工程,建设过程头绪繁多,任务艰巨。本文运用系统论的思想和基本原则,探讨了当前环境下医院信息化建设的基本思路。     

交换式光纤数字矩阵在交通监控中应用的优势

针对交通视频监控系统,分析了矩阵技术的发展历史及优缺点,指出交换式光纤数字矩阵系统在交通监控系统应用中与传统矩阵相比具有的明显优势.     

HDPE(高密度聚乙烯)管的施工工艺

文章介绍了HDPE(高密度聚乙烯)管的施工工艺,阐述了HDPE管作为一种新型雨水管道材料具有的施工特点和优越性,并与传统雨水管道施工进行了比较.最后经过实践证明,HDPE管施工工艺达到了提高工效、降低成本的效果.     

中国先进研究堆自然循环程序的开发及应用

针对中国先进研究堆(CARR)的具体结构以及自然循环建立的过程中冷却剂流动会发生逆转的特点，开发了自然循环瞬态计算程序．程序对CARR的低压运行系统以及自然循环建立过程中可能出现的流动状态以及换热形式进行了充分考虑．根据微分方程组刚性的强弱，计算中交替使用Adams预测一校正法和Gear方法进行数值求解．通过计算发现：应急冷却系统的投入明显地降低了CARR的冷却剂温度以及其他热工参数，更加有效地保证了CARR的安全运行．本程序可以作为CARR热工安全分析工具，并可为CARR停堆后各设备的运行方案提供理论分析基础．     

断层破碎带隧道围岩敏感性及沉降控制分析

为探明施工隧道穿越断层破碎带时何种断层形态对围岩稳定性影响最为显著,以绵九高速公路五里坡隧道不同断层形态为例,采用三因素四水平数值模拟正交试验对围岩敏感性分析。此外,为避免隧道开挖至断层破碎带时围岩发生较大变形及破坏,保证隧道施工过程安全,对断层的响应特性进行概括,需对断层段围岩注浆加固提高其稳定性。最后,对注浆加固圈厚度分别为：0m、1m、2m、3m的断层段隧道施工过程进行FLAC 3D三维模拟,采用位移控制率均值K对隧道断层及前后段整个区段的围岩控制效果进行定量评价。结果表明：1）断层倾向在各水平条件下变化时,拱顶沉降和边墙位移基本不发生改变,其余两因素对隧道拱顶沉降和边墙位移的影响程度分别为：断层厚度＞断层倾角、断层倾角＞断层厚度。2）注浆加固圈厚度由0m递增至3m时,隧道轴向位移和塑性区面积依次减少,但注浆加固效果也明显下降。3）通过围岩控制率k定量分析注浆加固对位移的控制效果,断层前后段的位移控制率均小于断层处。可见,在既能保证工程安全,又能减少注浆的使用,加固圈为2m时效果最好。     

建筑垃圾在路基填筑中的应用综述

建筑垃圾再生料作为新型环保、可循环利用材料,已经受到了广泛的关注。若能将其应用在道路工程中,不仅可以减少对砂石的开采,节约资源,还能降低工程的成本。这对中国公路建设的发展具有重要意义。然而由于建筑垃圾再生料相对天然骨料而言有着强度低、吸水率高等缺点。因此,建筑垃圾再生料路基与传统路基相比会存在明显的差异。将根据现有的研究成果,对建筑垃圾再生料在路基填筑时的基本性能、路用性能以及沉降变性特性进行阐述。最后分析并展望了未来的研究方向,有助推动建筑垃圾再生料在路基工程的应用。     

Ground effects on magnetooptic Bragg cells

Propagation equation of magnetostatic waves in an arbitrarily magnetized yttrium-iron-garnet/gadolinium-gallium-garnet waveguide coated with perfect metal planes is obtained using the method of the surface magnetic permeability. And ground effects on magnetooptic Bragg cells are investigated with the magnetooptic coupled-mode theory. Theoretical analysis indicates that, diffraction efficiency of guided optical waves can be improved by adjusting the spacing of the metal plane from the ferrite film, and ground effects on the diffraction efficiency will be enhanced using an appropriately tilted bias magnetic field. In the metal clad waveguide system, the magnetostatic wave frequency at which the diffraction efficiency peak is obtained corresponds to the “zero-dispersion” point, Performance of RF spectrum analyzers in this system can also be improved by comparing with the case of the sandwich waveguide. Therefore, magnetooptic Bragg cells with the metal clad waveguide are potential applications to the microwave communication and optical signal processing.     

The mean residence time of river water in the Canada Basin

Seawater was collected from the western Arctic Ocean for measurements of 18О, ^226Ra and ^228Ra. The fractions of river runoff and sea ice melt-water in water samples were estimated by using δ^18О-S-PО^＊ tracer system. The mean residence time of river water in the Canada Basin was calculated based on the relationship between ^228Ra/^226Ra）A.R. and the fractions of river runoff in the shelf and deep ocean. Our results showed that the river runoff fractions in the Canada Basin were significantly higher than those in the shelf regions, suggesting that the Canada Basin is a major storage region for Arctic river water. ^228Ra activity concentrations in the Chukchi shelf and the Beaufort shelf ranged from 0.16 to 1.22 Bq/m^3, lower than those reported for shelves in the low and middle latitudes, indicating the effect of sea ice melt-water. A good positive linear relationship was observed between ^228Ra/^226Ra）A.R. and the fraction of river runoff for shelf waters, while the ^228Ra/^226Ra）A.R. in the Canada Basin was located below this re-gressive line. The low ^228Ra/^226Ra）A.R. in the Canada Basin was ascribed to ^228Ra decay during shelf wa-ters transporting to the deep ocean. The residence time of 5.0-11.0 a was estimated for the river water in the Canada Basin, which determined the time response of surface freshening in the North Atlantic to the river runoff into the Arctic Ocean.     

Paleoclimate change recorded in the red earth and brown-yellow sediment of Late Quaternary for northeastern part of Guangdong Province, south to the Nanling Mountains, China

The paleoenvironment indicated by the geochronology, major oxides SiO2, Al2O3 and TOFE （Fe2O3 ＋ FeO）, and CIA （Chemical Index of Alteration） value of the red earth and brown-yellow silt primarily characterized by the Linjiang stratigraphic section, based on the geological investigation of Late Quaternary along the river banks of northeastern part of China＇s Guangdong Province, south to the Nanling Mountains, allow us to hypothesize that the red earth on the first terrace in northeastern part of Guangdong belongs to reticulated red clay developed in a hot-wet environment of the last interglacial period （132-73 ka BP）, similar to the monsoon environment in the northern margin of modern tropical zone, while the overlying brown-yellow silt layer mainly accumulated in a monsoon environment of warm temperate zone in the last glacial period （73-11 ka BP）, with the aeolian sand LJ3 representing an extreme period of worsening climate. Such a hypothesis corresponds well with predecessors＇ research on the paleoenvironment indicated by abundant fossils in both south and east to the Nanling Mountains. Hence, it follows that the bioclimatic zone did experience a large and rapid vicissitude in northeastern part of China＇s Guangdong Province, and even in the full extent of the region south to the Nanling Mountains from the last interglacial period to the last glacial period, with the red earth being replaced by the brown-yellow silty sediment, and even maybe with the Ailuropoda-Stegodon Fauna being replaced by the Penghu Fauna. This study may provide an important geological demonstration for the environmental response to global change in China＇s low latitudes on a 10 ka scale.