发展吉林玉米经济战略的研究

玉米经济在吉林农业经济中占有举足轻重的地位,就全省粮食产量而言,玉米播种面积占总面积的68%以上,玉米产量占粮食总产量的80%.因此,制订符合买方市场要求的玉米生产、深加工、销售经营战略,对促进吉林经济发展和农民增收,有着十分重要的现实意义和积极影响.     

隔震结构复位弹簧刚度的敏感性分析

摩擦滑移隔震技术是开发应用最早的基底隔震技术之一。本文通过一个算例，对复位弹簧的刚度对隔震结构的隔震效果的影响作了定量分析，并给出了复位弹簧刚度选取的参考性建议。     

黄石市郊蔬菜基地重金属含量及评价

对湖北省黄石市郊区蔬菜生产基地5种有害重金属Hg、As、Pb、Cd、Cr进行了检测，以国家规定的无公害蔬菜产地环境标准评价重金属污染状况，结果表明，团城山区、西塞山区和江北农场蔬菜基地的重金属综合污染指数均低于0．7，污染程度均为安全，污染水平为清洁；下陆区蔬菜基地重金属综合污染指数为1．0，污染程度为警戒线，污染水平为尚清洁。     

The effect of the surrounding landscape matrix on mangrove bird community assembly in north Australia

Mangroves are highly threatened ecosystems yet their community ecology is poorly understood. We examined the ecological determinants of bird community assemblage in floristically depauperate mangroves. Birds were surveyed using line transect methods. Large mangrove patches supported fewer species than smaller patches. Patches did not comprise nested species subsets and the bird species richness of several small patches combined was greater than a single large area. The number of mangrove dependent species in a patch was area-dependent suggesting these species may be resource limited, although there was no species density compensation. There was a clear effect of the surrounding habitat, with matrix species accounting for ∼45% of bird species in a patch. Patches surrounded by tropical savanna were relatively species-poor, while regardless of size, patches including monsoon rainforest were relatively species rich. Null model analysis of non-random assemblage structure (nestedness and species co-occurrence) revealed no deterministic structure to the overall mangrove species assemblage. These analyses described a random pattern of bird distribution and with no evidence of density compensation this suggests that competition is a weak structuring force of mangrove bird assemblages. The lack of nestedness and the random co-occurrence of species are consistent with the matrix-dependence of bird community composition. Conservation plans should treat mangrove patches as part of a habitat mosaic and incorporate many smaller mangrove patches rather than just big ones. Consideration of the nature, extent and diversity of the surrounding matrices is vital in managing and conserving mangrove bird communities.     

基于知识库的施肥决策系统及应用

针对作物推荐施肥系统中知识与数据紧密结合、模块固化的缺点,提出基于知识库思想的施肥决策系统实现方法,通过采用知识库作为区域实体事实数据与程序代码的接口,依托推理机实现施肥知识与系统的有机集成,解决施肥决策系统常面临的可扩展、可自定义等需求.该文对施肥知识库与数据实体的相互关系、施肥知识分类、表达、存储以及应用设计等进行了详细讨论.应用该思想设计开发施肥系统,能够较好地模拟现实中的施肥决策过程,目前在实践中已得到较好的应用.     

案例教学法在《地基与基础》教学中的应用

本文针对《地基与基础》课程实践性较强的特点,提出了利用案例教学法来提高教学质量的观点;并结合实例阐述了案例教学法的步骤和特点;同时也总结了案例教学过程中容易出现的问题。     

城市滨水区绿化景观设计中的人性需求初探

滨水区是城市中特定的空间,是城市中人类活动与自然过程共同作用最为强烈的地带。这些空间场所需具有环境优美、绿化宜人、服务设施完善、视觉景观舒适等特点,来满足人们对水的特俗感情。本文结合牡丹江地区设计实践,针对城市滨水区绿化景观设计中人的心理需求进行了初步探讨。     

明确发展方向推进林木良种基地建设

林木良种是提高造林成效的关键,良种基地是培育林木良种的源泉.我省目前建成有各类良种基地60多个(其中,国家重点林木良种基地6个、省级重点林木良种基地10个),总面积近2 000 hm2,年产林木良种3万多kg、良种穗条4 000万条,初步形成了以种子园、采穗圃为骨干,优良种源区母树林、采种基地为补充,选、引、育、繁、推...     

乡土杨梅嫁接改造成活后的生长特性调查

对嫁接改造后3 a生植株的生长进行调查,结果表明,采用不同乡土杨梅树种作砧木嫁接,成活后嫁接枝长、冠幅生长速率不同.大树杨梅其接穗基径与嫁接枝长、冠幅生长呈指数函数关系变化,接穗基径为5.1～6.0 cm时,树冠的增幅较快;矮杨梅其接穗基径与嫁接枝长、冠幅生长之间都呈线性关系变化,随接穗基径的增大,嫁接枝长、冠幅生长也随之增大.     

共建校内外实习基地 提升食品专业实践教学质量

实习基地是食品科学与工程专业学生进行实践教学活动的重要场所,对培养学生的实践能力和创新能力都有重要的作用。通过分析现阶段生产实习的现状和问题,提出了相应的解决方法,实行校内外实习基地共建,并应用于生产实习教学改革,取得了良好的效果。