一种基于组合模型的时间序列数据挖掘系统

提出了一种新的时间序列数据挖掘方法———基于BP(Back Propagation)神经网络和回归分析的组合时间序列数据挖掘模型.重点讨论了神经网络———回归———线性神经网络组合模型的建立过程,强调了通用性,并应用于浙江省可持续发展预测,取得了满意的结果.该组合模型采用神经网络技术来确定权重系数,提高了对复杂非线性系统的拟合能力,为时间序列数据挖掘提供了一种新的实用方法.     

氯普鲁卡因复合芬太尼硬膜外麻醉在剖宫产中的应用

目的探讨提高硬膜外麻醉效果的方法。方法选择择期或急诊剖宫产患者60例。随机分成三组:A组采用3%氯普鲁卡因行硬膜外麻醉,B组采用3%氯普鲁卡因复合0.1mg芬太尼行硬膜外麻醉,C组行复合腰麻硬膜外麻醉。结果B组麻醉起效时间显著短于A组,麻醉效果显著优于A组(P<0.05),但麻醉效果与C组比较无显著性差异(P>0.05)。结论剖宫产硬膜外麻醉时使用3%氯普鲁卡因复合0.1mg芬太尼能明显提高麻醉效果。     

基于模糊评判的组合导航自适应信息融合方法

针对组合导航系统在载体实际运动中,存在着局部滤波器精度急剧下降和滤波发散问题,并且会给整个联合卡尔曼滤波器带来污染,提出基于模糊评判的自适应信息融合方法。给出了评价滤波器性能的滤波结果可信度定义和模糊评价方法,并在此基础上进行信息分配保持全局估计精度和控制滤波发散。理论分析与仿真结果表明,该方法比常规联合卡尔曼滤波器具有更高的精度和可靠性。     

热力—表面活性剂复合驱油研究

在稠油注蒸汽热采的过程中添加表面活性物质可以提高热采的开发效果,这种开发方式在油田现场已得到初步应用.对稠油油藏热采添加表面活性剂复合驱过程中的主要物理化学现象进行了数学描述,建立了比较完整的热力—化学复合驱数学模型;运用自行研制的软件对实际稠油油藏蒸汽驱、复合驱开发进行了模拟计算.研究表明:表面活性剂性质、浓度、注入总量等在很大程度上影响着复合驱的开发效果;在适当时机进行稠油复合驱开发,可以提高稠油采收率,并获得较好的经济收益.     

巴公电厂热电联产改扩建工程水土保持的监测

介绍了巴公电厂热电联产改扩建工程水土保持工作中的监测区域、监测点布设、监测内容与方法、监测时段与频率、监测机构和监测监督制度等.     

The cell cycle: a new entry in the field of Ca2+ signaling

Ca²⁺ signaling plays a crucial role in virtually all cellular processes, from the origin of new life at fertilization to the end of life when cells die. Both the influx of external Ca²⁺ through Ca²⁺-permeable channels and its release from intracellular stores are essential to the signaling function. Intracellular Ca²⁺ is influenced by mitogenic factors which control the entry and progression of the cell cycle; this is a strong indication for a role of Ca²⁺ in the control of the cycle, but surprisingly, the possibility of such a role has only been paid scant attention in the literature. Substantial progress has nevertheless been made in recent years in relating Ca²⁺ and the principal decoder of its information, calmodulin, to the modulation of various cycle steps. The aim of this review is to critically discuss the evidence for a role of Ca²⁺ in the cell cycle and to discuss Ca²⁺-dependent pathways regulating cell growth and differentiation. Received 2 March 2005; received after revision 9 May 2005; accepted 24 May 2005     

全息美容镜的制作与机理

本文介绍了具有美容与艺术欣赏价值双重功能的全息美容镜。详述了它的制造过程,初步解释了全息美容镜形成的化学反应机理,并指出它是制造全息反射组合式光学元件的一种新类型、新方法。     

浅谈组合楼板在工程中的应用特点

轻钢-混凝土组合结构结合了轻钢结构和混凝土结构的优点，具有施工方便、工期短的特点，同时使结构具有良好的抗震性能和耐火性能。     

Chymotrypsin-like and trypsin-like protease activities in the sea urchin (Hemicentrotus pulcherrimus) egg

Proteolytic activities in extracts of sea urchin eggs were examined using SDS (sodium dodecyl sulphate)-polyacrylamide gels. In the unfertilized eggs, proteases were detected as bands corresponding to the molecular weights of 40 kD and 26 kD on the gelatin gel, and 35 kD and 30 kD on the casein gel. Using various protease inhibitors, it was found that 40 kD, 30 kD, and 26 kD are chymotrypsin-like proteases and that 35 kD is a trypsin-like protease. The activity of the 40 kD chymotrypsin-like protease was found to be almost completely lost after insemination.