Population trends and prospects

For the next 20 years there is likely to be a slowing of population growth rates for all areas of the world except Africa. The present population of developed countries is expected to increase by about 12 percent by the year 2000; that of all developing countries is expected to increase by about 50 percent. The momentum of population growth is strong; a few analysts suggest that growth may cease at 8 billion, but a figure of more than 10 billion seems much more likely.     

微生物学课程教学改革措施及成效

介绍了信阳农林学院对微生物学理论及实验教学进行的改革措施,包括改进教学手段与方法、考试方式改革及教学信息反馈、创新实验设计、注重实践与校企互动培养创新型人才模式、开展教研室活动等,并分析了以上教学措施对提高学生学习的积极性、主动性及综合素质方面的显著效果。     

波兰小浆果育种项目的目标和成就

波兰小浆果育种主要在波兰果树和花卉研究所进行.育种目标主要是培育果实品质佳、适应当地气候和土壤条件、对流行的病虫害具有可以接受的抵抗能力、适合鲜食和适宜不同形式加工、抗寒力强并且具有很强的花期抗霜害能力的优良品种.为了扩大遗传基础,最近已经开始了种间杂交工作,并已培育出很多的优良品种.黑穗醋栗品种有"Bona","Ceres","Ores","Ruben","Tiben","Tines"和"Tisel";醋栗品种有"Hin-8el"和"Resika";红树莓品种有"Benefis","Beskid","Laszka","Nawojka","Pokusa","Polana","Polesie","Polka"和"Poranna Rosa";黑莓品种有"Gazda"and"Orkan";草莓品种有"Aga","Astra","Duht","Elkat","Elsar-iusz","Era","Fara","Feriusz","Filon","Filut",Hokent","Marduk"."Panon",Salut",Segal","Selvik"and"Vikat".这些品种显示出很强的市场前景并且在生产中的使用面积逐年增加.     

Ocean energy: forms and prospects

The nature and distribution of power sources of the sea other than petroleum are discussed, along with possible entrées for their use. Waves, tides, currents, and salinity and temperature gradients all have the potential to contribute useful power. Submarine geothermal sources, salt domes, ice, and other marine-associated concentrations may be more important. There are opportunities to employ these marine power resources directly rather than for contributions to power grids or power-intensive products. Ancillary employment of the seawater as a coolant and of the sediments below the seabed for the disposal of nuclear wastes may be even more important uses than employment of the power that the sea contains.     

土壤微形态学的研究进展与展望

作为土壤学的一个重要分支学科,土壤微形态学自从创建以来,通过国内外学者的创新性研究,在其研究技术与研究内容方面都取得了长足的进展.简单回顾了土壤微形态学的发展历程,综述了土壤微形态研究的主要进展,并对其未来的发展作出了展望.     

螺旋藻研究现状及展望

从分类、地理分布、藻种选育、食品加工与医药、环境保护等方面综述了螺旋藻的研究进展,并对其应用前景进行了展望,以利于人们更好地认识、了解和高效开发利用螺旋藻.     

Neutron scattering: progress and prospects

Over the last decade the unique properties of neutrons have proven useful in a growing number of scientific disciplines. Neutron scattering, traditionally the probe of choice for many magnetic and spectroscopic studies, is now firmly established as an invaluable complement to x-ray scattering for structural and dynamic studies within many other areas of the material sciences, chemistry, and biology. In recent years the instruments and techniques have matured to the point where they are of increasing relevance to the understanding and design of improved practical, everyday materials.     

弗兰克氏菌的研究进展与前景

弗兰克氏菌（Ｆｒａｎｋｉａ）与植物共生结瘤固氮的意义不亚于豆科植物的根瘤菌,并有更广阔的研究开发前景．本文简要介绍了弗兰克氏菌的研究历史;着重评述了弗兰克氏菌的宿主种类、菌种分类、固氮数量、适应范围、固氮特性、新共生体系和侵染作物等的研究进展;并对弗兰克氏菌的进一步研究开发提出思路和展望     

热科院科技成果转化问题探讨

总结中国热带农业科学院科技成果转化取得的成绩,分析影响其科技成果转化的因素,并提出建议与对策。     

论苏洵的史学成就

苏洵有《史论》三篇,可以说明苏洵的史学成就。这就是在义一体二的史学思想指导之下,对史学史上有代表性的史著《史记》和《汉书》进行评价,最后在修《嘉祐谥法》的过程中实践了自己的史学主张。     

我国太空育种的成就与展望

太空育种是集航天技术、生物技术和农业育种技术于一体的农业育种新途径,是当今世界农业领域中最尖端的科学技术课题之一。介绍了太空育种的意义、发展历程和我国在此方面所取得的丰硕成果及其前景展望。     

水稻杂种优势利用的成就与展望

主要从育种的角度,简要回顾了中国水稻杂种优势利用的研究历史,概述了育种成就、推广应用情况、最新研究进展和趋势,展望了研究发展前景.