环鄱阳湖产业和城镇群的历史及现状浅探

历史上,环鄱阳湖地区以执中国牛角的茶业、瓷业、稻米业、水运业、造纸业、制版印刷业和教育业为中心,形成了繁荣的产业群和城镇群,它们从两宋历元、明、清至民国初年逾千年而不衰。本文用历史档案和翔实的历史资料对其作了求证和较系统的描述,同时,也初步探索了这个产业和城镇群在近现代走向衰落的原因以及至今仍发展滞后的现状。     

核电站常规岛直接蒸发冷却空调机组的测试分析

结合工程实际要求,对海南、浙江、巴基斯坦等地区3个核电站工程的3台直接蒸发冷空调机组进行实验测试,得到送风量、风速、温度、相对湿度及阻力等机组的性能参数,满足3个区域的核电空调的要求.测试结果表明,填料厚度分别为100mm,200mm,300mm,其效率分别为72.7％,85.7％,93.6％.直接蒸发冷却空调机组不仅与填料厚度有关,而且与应用区域的干球、湿球温度有较为明显的关系.     

三氮唑,噻二唑和四唑席夫碱的植物激素活性

首次对三氮唑，噻二唑和四唑Schiff碱的生物活性进行了系统报道，生物活性测试结果发现，这些Schiff碱大多数具有明显的植物激素活性，其中三氮唑的Schiff碱具有优良的细胞分裂素活性，四唑的Schiff碱具有很好的生长素活性与生根性能，而噻二唑的激素活性则稍差，生测试验结果还证明，氯代苯甲醛，噻吩甲醛和吲哚甲醛生成的Schiff碱生物活性更好。     

轻钢结构单层厂房整体稳定性的影响因素分析

鉴于当前国内外轻钢结构单层厂房工程事故特点,对其整体稳定性的研究还十分欠缺,不利于轻钢结构单层厂房大力推广和广泛应用;本文通过对一些轻钢结构单层厂房垮塌典型实例进行综合分析,分别阐述了轻钢结构失稳的原因、细部结构对轻钢结构稳定性的影响.通过分析,得出几点对轻钢结构整体稳定分析影响因素有价值的结论和建议.这些结论和建议对轻钢结构设计和施工具有一定的参考价值.     

贵州新分布的植物

通过标本鉴定和查阅相关资料,发现了贵州的10个新分布种,它们是凹脉桃叶珊瑚Aucuba cavinervis、勐腊乌蔹莓Cayratia menglaensis、锐齿桂樱Laurocerasus phaeostictaf.ciliospinosa、滇桂木莲Manglietia forrestii、四川木莲Manglietia szechuanica、新宁含笑Michelia xinningia、双蕊野扇花Sarcococca hookeriana var.digyna、团花山矾Symplocos glomerata、长萼栝楼Trichosanthes laceribractea和越南勾儿茶Berchemia annamensis。     

The relative exploitation of annuals as larval host plants by European butterflies

Theoretically, Lepidoptera should be able to adapt to using annuals as larval host plants through increased development rates and migration capacity. Even so, we show that annuals are used less frequently as host plants than expected among British and continental European butterflies. In particular, no example has been found of a European butterfly monophagous on an annual plant over its entire range. Use of annuals is proportionately greater among species that exploit increasing numbers of host plants and among subsidiary host plants than among primary (main) host plants. Annuals as host plants change status as habitat components with changes in species' spatial dynamics. The statistical findings point to perennials as providing host plant refuges, whereas the few case examples of site monophagy suggest that annuals can become valuable complementary resources during range extensions such as those currently associated with climatic warming. Annuals are more likely to be used in highly restricted circumstances, when environmental conditions allow the plants to persist over prolonged periods (i.e. when they are behaving like biennials) or when their spatial predictability is high because of low seed dispersal.     

The precipitation strengthening behavior of Cu-rich phase in Nb contained advanced Fe-Cr-Ni type austenitic heat resistant steel for USC power plant application

Copper has been used as a strengthening element in newly developed Fe-Cr-Ni type austenitic heat resistant steel for inducing Cu-rich phase precipitation to meet high temperature strength requirement f...     

华山松在太原市森林公园的定植与管护

城市园林是衡量城市现代化文明程度的重要标志，是提升城市品位，满足人民群众物质文化生活水平需要的重要功能区。文章分析了华山松的特性及地理分布，结合太原市森林公园的自然条件，提出了华山松栽培后管护的具体做法。     

怀新高速公路边坡植物群落特征研究

本文分析了怀新高速公路边坡植物群落特征，揭示了高速公路边坡植物群落的分布情况及生长状况，为高速公路边坡植物群落的科学营建提供科学依据。     

簸箕柳种内杂交F1群体株高生长曲线的拟合

对簸箕柳F1杂交组合的450株子代在1 a内的苗高生长进行了测定,利用Logistic、Gompertz和Von Bertalanffy等3种非线性模型对其生长变化规律进行拟合及分析,结果显示,3种模型的拟合度(R2)均在0.98以上.Logistic和Gompertz模型的早期拟合值与实际值偏离较大,而Von Bertalanffy模型在整个测定时期其拟合值与实际值均很接近,拟合度可达0.994.由此可建立理想的统计模型来追踪簸箕柳F1苗高生长率的变化.