纤维素在鱼类饲料中适宜含量的研究概况

纤维素是鱼类重要的营养素,文章分析了有关纤维素的作用、鱼类饲料中纤维素的适宜含量及影响因素、饲料中纤维素含量过多的危害,同时,对一些研究方法也做了相应评价,对未来的研究方向提出了个人观点。     

基于[火用]方法的空调冷热源系统优化决策

结合方法和热经济学原理建立了空调冷热源系统的分析模型,阐述了产品成本是评价冷热源系统方案优劣的关键因素.采用多目标模糊决策方法,综合考虑了单位产品成本、初投资、技术先进性、安装面积、运行安全可靠性、维护管理难易程度和环保性等多种影响因素,基于方法的冷热源优化决策算法.通过应用实例,说明了此新优化决策算法相比工程中传统决策方法,可靠性更高,使各决策方案间优劣区分度更加明显。     

红富士苹果花芽孕育时期的研究

以七年生‘红富士’苹果为试材,采用摘果摘叶法和不同时期喷施 GA_3法研究了苹果花芽孕育的时期。结果表明:苹果花芽孕育时期由二个不同的生理过程所组成:起动过程和完成过程。摘果处理可以判断起动过程是否完成,摘叶和喷施 GA_3可以判断完成过程是否结束。花芽孕育起动后至完成,对 GA_3较为敏感,这时期用低浓度 GA_3处理就可以明显减少花芽形成,但是,GA_3对是否起动似乎不起主要影响。本试验的‘红富士’苹果花芽孕育起动过程在盛花后34～45d,完成过程在盛花后45～77d。     

Interpretation and Compilation of Landsat TM Imagery for Land-use and Site Classification Mapping in the Korqin Sandy Lands, NE China

For the purpose of of forestation, planning and development in the Three-North Region, a series of 6 Landsat TM scenesfrom 1996 to 1997 were used to classify land-use conditions in the whole Korqin Sandy Lands at eastern part of Inner Mongolia, China, with an area of about 430×306 square kilometers. Later on, Site classiflcation was made and mapped for the 4 southern sandy counties. The annotation symbol for each agglomeration of site condition is comprised of six parts: land unit, land use pattern, soil texture, under ground water table, top-soil existence, wind erosion or salinisation condition. Field expedition and soil file augering help information extraction from the satellite imagery. The products include a land-use classiflcation map at scale 1/200,000 of the whole Korqin Sandy Lands, and a collection of site classiflcation maps at scale of 1/50,000, consisting of 135 pieces (42.8 cm×30.8 cm each). Electronic version of the maps is in raster form.     

Introduction of Action Plan of Forestry Sustainable Development of Qinzhou-Fangchenggang area, Guangxi Zhuang Autonomous Region, China

Guanngxi Autonomous Region is an important tropical forestry region in south of China. The main purpose of this research supported by FAO is to generate action plan for sustainable forestry development of this region. Through two-year broad and deep investigation, the programme of the action plant has been made, which includes 12 fields, 38 projects, with duration of 5 years.     

陕晋蒙三角区自然环境面临的主要灾害及对策

陕晋蒙三角区是我国未来的一个新经济区,在全国具有重要的地位。本文从该区的特点出发,论述了自然环境的主要灾害,进而提出了减灾的相应措施与建议。随着能源基地经济建设的飞跃发展,必须坚持开发与治理同步进行;提高植被覆盖率;防止水土流失;实现综合;强化环保监督。只有这样,才能实现林茂粮丰和经济腾飞的目的。     

内蒙古和林格尔县人口合理容量的系统动力学模拟分析

本文以系统动力学模拟方法具体分析黄土高原地区一典型县的人口合理容量问题。结果表明,除非合理的标准远比目前全国平均水平为低,该县目前的人口及2000年前的人口预测值与相应的人口合理容量不相适应。改变这种局面的手段只有迅速提高该县社会经济发展水平,大力发展非农产业,积极治理环境。