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1.
Drawn on the data col ected by surveying 1 340 urban households from six cities in China, this paper estimates the impacts of demographic structure and population aging on household meat consumption, b... 相似文献
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后脱贫时代国内外农业科技发展经验及其对我国的启示 总被引:1,自引:0,他引:1
农业科技扶贫在部分地区被认为是农户摆脱贫困、实现区域经济发展的重要途径.针对精准扶贫战略实施过程中出现的农业科技扶贫制度不完善、农户知晓度及参与率低等突出问题.在借鉴国内外农业科技发展成功经验的基础上,提出相应的优化建议:完善相关制度设计,激发科技人员参与的积极性,鼓励各地区因地制宜实施差异化组织管理模式,加大农业科技... 相似文献
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本文针对家装设计、绘图和识图能力对装饰专业的重要性等方面,对建筑装饰专业学生的就业方向和职业能力的培养进行了粗略的探讨。 相似文献
4.
Abstract – We performed a tagging study on one of the spawning populations of northern pike ( Esox lucius L.) of the River Kajaaninjoki in Finland. Northern pike is the main predator in many lakes and rivers in the northern hemisphere. Previous tagging studies have shown a general tendency to sedentary behaviour by pike. Whether individuals in a fish population adapt a sedentary or moving strategy may affect population persistence. To study if the spawning population consists of sedentary or moving individuals and the pattern of movements, we tagged 40 pike with radio transmitters and followed them from May 2002 to June 2003. Pike were caught and tagged during the spawning season in the mouth of the River Kajaaninjoki which flows into one of the largest lakes in Finland, Lake Oulujärvi. Our results suggest that the pike spawning population consisted of sedentary pike ( N = 16) dwelling the whole year in the river, and moving pike ( N = 24) which moved to Lake Oulujärvi after the spawning period. Pike exhibited homing behaviour, as most of the migrating pike returned to the same spawning area in the following year. Large pike had a higher movement rate than small pike during the summer and seasonally the movement rate was lowest during the spring and highest during the summer. 相似文献
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李彦侠 《北京农业职业学院学报》2019,33(1):22-26
原产欧美的花枝鼠,深受人们喜爱,已成为中国家养鼠的新品种。通过对花枝鼠的识别要点、生活习性及繁殖要点的介绍,从家庭养殖环境选择、饲料的选择与喂养、科学饮水、疾病防控等方面,论述了花枝鼠的家庭健康养殖技术,为家庭健康饲养花枝鼠提供参考。 相似文献
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应克荣 《安徽农业大学学报》2005,(1):106-109
李白一生写下了大量的怀乡诗。随诗人人生际遇的变化,在不同的阶段呈现不同的意蕴和内涵.早年的怀乡诗在壮怀激昂中蕴孽着淡淡乡愁,中年的怀乡诗更多怜子思亲的伦理亲情,晚年的怀乡诗体现了强烈的回归意念。 相似文献
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James Sedalia Peters David T. Damery Richard W. Wilkie 《Journal of Sustainable Forestry》2017,36(1):76-89
The article presents a material-geographic study of contemporary log home manufacturing in the Eastern Woodlands of North America. The study investigated relationships between log conversion (i.e., processing) methods and regional location. Manufacturers were grouped by their conversion methods, using hierarchical cluster analysis; and analyzed for spatial correlation, using standard deviational ellipses (SDEs). Tree species utilization, log treatment, horizontal surface type, and corner notch type were found to be spatially differentiating. These attributes were tested for their ability to predict manufacturers’ culture region using multinomial logistic regression (MLR) models. Tree species utilization was an independent variable in all of the predictive models, suggesting a correspondence between building culture and ecological regions. This is consistent with earlier research. The findings suggest that location drives tree species utilization and, thereby, building methods. Like the eco-region itself, log conversion methods vary on a north-south gradient. It is argued that construction knowledge is geo-contextual and that the replacement of scientific wood extraction with ecosystem management as the central paradigm in forestry calls for geo-contextual approaches to sustainability in the construction industry. 相似文献