电子仪器发展趋势

本文在回顾了电子仪器近百年发展的历史的基础上,对国际电子仪器制造商、电子仪器行业及电子仪器本身的发展趋势,以及我国电子仪器的发展情况进行了分析归纳和总结.     

Simulation of runoff and phosphorus transport in a Carpathian catchment,Slovakia

A comprehensive, GIS‐based modelling approach is developed to estimate runoff and phosphorus transport within a watershed at a daily time step. The approach relies on the use of GIS data for deriving major critical model parameters that exhibit distinct spatial variability over the catchment. Surface runoff is calculated by a modified rational method, which depends upon rainfall intensity, soil moisture status, slope, land‐use and soil characteristics. Phosphorus loading is estimated as a function of the runoff volume and the event mean concentration for different land use categories. A diffusive approximation method is used to trace runoff and phosphorus transport to the basin outlet. The modelling approach is tested in the Margecany catchment, Hornad River basin, Slovakia, to simulate runoff, phosphorus loading, and its transport on a daily time scale using data observed between 1995 and 2000. Satisfactory results of the hydrographs and phosphorus concentration at the basin outlet are obtained, though more efforts regarding the phosphorus cycling and its biochemical reactions need to be clarified by further research. Copyright © 2006 John Wiley & Sons, Ltd.     

马尔柯夫链预测法在证券指数预测中的应用

介绍马尔柯夫链预测法的模糊模型，该模型以集合的模糊划分为依据摒弃了清晰划分的不足．从而保证预测结果的精确性。将该模型应用在证券指数的预测上，取得了绝对误差、相对误差较小的结果。     

我国电力工业和发电技术未来发展趋势

传统工业化走的是通过高消耗追求经济数量增长和先污染后治理的道路。介绍在传统工业化面临严重危机的背景下,可持续发展战略和新型工业化的兴起和特点,充分体现了未来发展的要求。在分析、总结世界能源发展的经验和规律的同时,对未来世界能源发展进行了宏观预测。以科学发展观为指导,采用未来学的方法,结合我国国情、发展现状和近中期发展目标,对本世纪特别是21世纪前20a我国电力工业和发电技术趋势进行了初步探讨,对国家能源安全等问题进行讨论。     

可靠性预计方法及思考

本文介绍了可靠性预计的目的,并对当前较为常见的可靠性预计模型或方法做了比较和说明,也对造成可靠性预计局限性的原因做了分析,最后对在可靠性工程工作中对待可靠性预计的态度做了探讨.     

Effects of circumferential pick spacing on boom type roadheader cutting head performance

Effects of equal and unequal circumferential pick spacing on the performance of boom type roadheaders having cylindrical cutting heads are investigated. For this purpose, two experimental cutting heads with equal and unequal circumferential spacing are designed and manufactured. The cutting head with unequal circumferential spacing is specifically designed to prevent tool-holder overlap at the nose section. Manufacturing difficulties associated with equal circumferential pick spacing due to tool-holder overlap are discussed with solid modeling and practical applications. The heads are tested at Park Cayirhan Coal Mine in Turkey and their cutting performances are analysed. Although better cutting performance for equal circumferential spacing are predicted by force–balance analysis, in situ measurements of instantaneous (net) traversing speed and cutting rate, pick consumption rate and machine vibration show that no significant difference exists between the performances of the two cutting heads.     

对中国白酒业的忧思

中国白酒产业在20世纪80—90年代，曾经是“高税高利”产业。“利大于税”曾一度成为白酒产业的巨大经营优势。1994年以后，国家相继对白酒税收做了几次重大调整，至此，白酒产业已成“昨日黄花”，风光不再。2002年整体亏损面近1／3，亏损总额达8亿元。前50家企业年资产回报率大部分在3％—5％。相当一部分企业不足1％。因此。白酒产业呼唤“公平待遇”，希望国家为酒立法，“公平税赋”，让白酒业焕发新的生机，为国家“全面建设小康社会”做出新的贡献。(小雨)     

曲流河沉积亚相的地震识别方法

本文提出利用三维地震资料相干数据分析研究曲流河沉积相的方法，其优点是在地质分析的基础上，对沉积体系有较为明显的识别特征，且在钻井较少的地区尤为实用。该方法在济阳拗陷东北部上第三系应用中取得了较为明显的效果。     

基于小波除噪和神经网络理论的气固循环流化床颗粒浓度预测

提出了一种将混沌的相空间重构、小波包分析和神经网络相结合的新方法用于预测气-固循环流化床的颗粒浓度。首先利用小波包进行数据的消噪,然后用混沌方法重构相空间吸引子,用径向基神经网络拟合吸引子上的全局整体映射,构成混合预测模型。实验结果表明,将此混合模型用于预测气-固循环流化床的颗粒浓度,能达到较好的预测效果,预测精度比奇异值分解和傅里叶变换除噪高。     

平湖油气田储层及含油气预测

平湖油气田是东海第一个开发的复合型油气田 ,主要含油气层段为渐新统花港组油藏 (H2 -H8)和始新统平湖组气藏 (P1 -P1 1 ) ,首期开发区为F1、F2断块 ,二期开发区为B1、B2断块。在平湖油气田开发过程中 ,针对花港组油藏波阻抗与岩性相关性好 ,而平湖组中下部波阻抗与岩性相关性不好的这种地质和地球物理特点 ,应用国内外先进的技术和方法 ,尝试多种方法预测储层及含油气 ,取得了较好的预测成果。