电动绿篱修枝机的结构设计与研究

针对现有电动修枝机环境噪声大、资源消耗大和工作效率低等设计背景,提出了电动修枝机的工作原理和结构方案,设计了关键零部件,分析了试验结果。试验表明,该设计方案可行。     

通辽地区沙地果园改土培肥技术

本文介绍了沙地建果园的关键在于加强土肥管理,采用挖沟栽植、压绿肥、树盘覆草（生草）、抽沙换土、增施有机肥等技术措施,改良土壤,培肥地力,实现经济效益与生态效益共赢。     

经济发展与环境问题的思考

如何实现经济发展与环境优化相和谐,就是要解决发展中资源结构性安全和生态环境问题。既要加快地区发展,又要解决城乡发展不平衡,同时还要改进城乡建设的思路,提高城乡人居环境的效益,改善环境条件,保护并节约有限的环境资源。     

Response of Coniferous Forest Ecosystems on Mineral Soils to Nutrient Additions: A Review of Swedish Experiences

Nitrogen (N) is the only nutrient that promotes forest growth when given individually. An extra stem growth of 15 m 3 ha -1 is obtained during a 10 yr period following an application of 150 kg N ha -1 . Larger growth increases have often been the result of more intensive N fertilization. Lime or wood ash give a minor growth stimulation on sites with a carbon (C) to N ratio below 30 in the humus layer, while the opposite effect prevails on N-poor sites. Nutrients given as soluble fertilizers are readily taken up by trees. Boron deficiency may be induced in northern Sweden after N fertilization or liming. The ground vegetation may be altered by single-shot N fertilization, but long-term effects occur only for intensive regimes. Lime or wood ash may modify the flora if soil pH is significantly altered: the change will be in response to N availability. Fruit-body production of mycorrhizal fungi is disfavoured by chronic N input, but also by lime or ash. However, the mycorrhizal structures on root tips are less affected. Faunistic studies are not common and those present are mostly devoted to soil fauna. A practical N dose of 150 kg N ha -1 has no clear effect, but higher doses may reduce the abundance in some groups. Hardened wood ash does not significantly affect the soil fauna. Lime favours snails and earthworms, while other groups are often disfavoured. The response of aquatic fauna to terrestrial treatments has hardly been studied. N fertilization generally results in insignificant effects on fish and benthic fauna. Lime and wood ash reduce the acidity of the topsoil, but practical doses (2-3 t ha -1 ) are too low to raise the alkalinity of runoff unless outflow areas are treated. N fertilizer use in forestry and N-free fertilizers lack effects on acidification. N fertilization may, however, be strongly acidifying if nitrification is induced and followed by nitrate leaching. N fertilization often results in increased long-term C retention in trees and soil, but does not promote significant N 2 O losses. N may temporarily reduce CH 4 oxidation in soil, but there are indications of a long-term opposite effect. Lime and poorly hardened wood ash may cause losses of C from N-rich soils. Only a few per cent of added N are leached to surface water following practical N fertilization, while N-free fertilizers do not induce N leaching. Soil incubations and soil-water studies suggest an increased risk for nitrate formation and leaching where lime or wood have been added to N-rich soils, but increased leaching to surface water has not been observed. Wood ash causes a temporal increase in bioavailability of cadmium (Cd). Other fertilizers may indirectly increase the availability of heavy metals. Wood ash may contain radioactive caesium 137Cs, but addition of such ash does not increase radioactivity in plants and soil.     

广州建设环境友好城市实施保障机制

文章以科学发展观和环境友好型社会理论为指导,根据广州的实际,对建设环境友好广州提出八项保障机制:加强环境友好型法制化建设;建立环境与发展综合决策机制;建立生态约束机制;建立和完善鼓励机制;建立区域合作共生机制;建立社会参与机制;建立生态安全监测预警机制;建立生态补偿和投入机制。       

泸水县核桃产业提质增效技术措施

核桃作为泸水县主要经济作物树种,目前已经成为了泸水县林业产业的支柱,本文通过分析泸水县核桃产业中存在问题,提出泸水县核桃产业提质增效的技术思路,旨在建立泸水县高产优良的核桃产业。     

Effects of environment and variety on content and molecular weight of β-glucan in oats

Oat β-glucan has been shown to have cholesterol, insulin and glucose lowering effects, which are related to increased viscosity of the intestinal contents. Some important factors influencing the viscosity are molecular weight, structure and concentration. To study the effect of variety and environment on β-glucan content and molecular weight of β-glucan, four oat varieties were grown in 11 different environments (location × year combinations) in a field experiment. The β-glucan content varied between 2.3 and 3.2% and the average molecular weight of β-glucan between 1.73 and 2.02 × 10⁶ g mol⁻¹. There was a significant difference between varieties and environments for both β-glucan content and molecular weight of β-glucan. The effect of environment was much greater on molecular weight (71%) than on β-glucan content (42%), while the effect of variety was greater on β-glucan content (23%) than on molecular weight (4%). There was also a positive significant correlation between β-glucan content and molecular weight of β-glucan (p < 0.001, r = 0.46). These results show that β-glucan content is a better target for plant breeding than molecular weight. However, both factors are important for the physiological effects of β-glucan, and selection for high β-glucan content will probably also give higher molecular weight.     

城市土壤的压实退化及其环境效应

城市土壤普遍存在严重的压实退化现象。由于压实的影响,土壤物理性质发生了显著的改变:结构破坏、容重和硬度增大、孔隙度和渗透性降低。这些重要的变化对土壤生物活动、土壤物理-化学平衡和氧化还原状况、土壤的过滤和缓冲性能都产生影响。由此对环境产生严重的负面效应:地下水的自然回灌减少,地表径流量增加,降雨的径流洪峰加快、加大,地表水体的污染负荷增加。土壤温度、微生物活动、养分转化都不同于自然土壤,植物的生长也受到严重的影响。     

植入乌龙茶初制工艺改进夏秋名特绿茶品质的研究

针对用夏秋季茶鲜叶加工的名特绿茶苦涩味重、收敛性强、香气清淡和综合品质较差的问题,开展了夏秋季毛峰茶加工技术研究。采用植入乌龙茶初制的部分工艺,改善了夏秋季毛峰茶品质。提出了夏秋季毛峰茶加工的技术指标和最佳工艺流程。     

温室环境信息智能化管理研究进展

随着我国温室园艺业和信息技术的迅速发展,现代信息技术越来越多地应用于温室环境管理中,促进了温室环境智能化管理技术的发展。本文针对面向物联网的温室环境信息智能化管理需求,分别从温室环境信息获取、信息处理与决策服务3个方面对国内外研究进展进行了系统的分析和阐述,并提出了今后在温室环境信息智能化管理方面迫切需要开展的工作。