杨格不等式的推广和最优化解的存在域

给出了均值不等式和杨格不等式的推广形式,讨论了杨格不等式的最优化问题,并且给出了杨格不等式最优化解的存在域.     

Urban tree growth and their dependency on infiltration rates in structural soil and structural cells

Expanding tree canopies can be difficult to achieve in built environments because urban land is costly and urban soil inhospitable to vegetation so engineered planting systems offer a potentially valuable tool for achieving sustainable urban forests. Tree water uptake, performance and root distribution were assessed in systems of structural soil and structural cell. Structural soil relies on stone and soil, it is highly porous and designed to support tree root growth and possess pavement strength. The structural cell is made up of rigid structural units with 90% void space which is to be filled with soil. To evaluate tree performance under the conditions of fill and drain regimes in structural soil and structural cell, these two systems were subjected to three simulated infiltration rates. This study was conducted in April 2015 to April 2016 in the tropical equatorial environment of South East Asia. Infiltration rate affected both biomass accumulation and rooting depth. Species and substrate effect was significant for biomass and rooting characteristics but less prominent for transpiration. Biomass was greater for trees in structural cells, and Pouteria obovata was particularly sensitive to prolonged inundation. Rooting depth was always higher in the rapid infiltration indicating the negative effects inundation had on this parameter. Root system in the structural cell was deeper while those in the structural soil were wider. Samanea saman had better adapted to the drain and fill regimes, and this was despite Pouteria obovata being a coastal species and was expected to be flood tolerant. Species and substrate effect was weak (R² ranging from 0.20 to 0.28) but moderate drainage consistently led to higher transpiration. We conclude that structural soil and structural cell are potential solutions and provide a tool to overcome suboptimal urban growing conditions. The application of these solutions will allow for seamless integration of greenery with urban infrastructure.     

沼液营养液对快菜生长和生理特性的影响

以"四季快菜一号"为试材,以华南农业大学农化室叶菜A改良配方为对照(CK),设定沼液添加量为10%、20%、40%、60%、80%,研究了不同沼液添加量对快菜生长和生理特性的影响。结果表明:在营养液中添加一定量的沼液,能明显提高快菜植株的维生素C、可溶性糖、粗纤维和粗蛋白含量,并能提高蔬菜产量,沼液添加量为40%时效果最好,但对粗脂肪和叶绿素相对含量提高并不明显。     

改善喷射沉积耐热铝合金板坯轧制成形性能的研究

喷射沉积Al-8．5Fe-1．3V-1．7Si(8009)耐热铝合金板坯是由基体金属和孔隙、少量颗粒边界的氧化膜组成的，微观组织缺乏良好的冶金结合，直接采用轧制使其致密化产生塑性变形，在工艺上存在极大的难度，轧制时易出现板坯表面裂纹及边裂。本文研究了8009合金的包套轧制、交叉横轧工艺，实验结果表明：采用包套轧制、交叉横轧工艺，有效地改善了喷射沉积板坯的轧制成形性能，成功制备出厚度为0．6～1．0mm的薄板。     

供暖锅炉消烟除尘装置的选择

各种锅炉消烟除尘设备都有自己的使用范围,本文主要介绍了供暖锅炉在消烟除尘选用中应考虑的问题,阐明选用消烟除尘设备时要充分了解其技术范围及其经济性能。     

一类p-Laplacian方程非平凡解的存在性

用山路引理得到了一类带有Dirichlet边值条件的p-Laplacian方程的非平凡解的存在性及多解性.     

坩埚移动式喷射共沉积制取铝基复合材料的技术

提出了坩埚移动式喷射共沉积制备铝基SiC颗粒增强复合材料的装置和方法,并与传统的喷射共沉积装置进行了比较.在SiC颗粒增强相加入方法中,新工艺采用了双环缝复合雾化器和螺杆给料负压引流输送装置,解决了大尺寸、高SiC体积百分比复合材料坯制备技术问题.通过上述装置已经制备出Φ800×1000mm,SiC含量为20wt%,重达1t的铝基复合材料.经后续挤压、锻造加工,制备出了性能优异的6000Al/SiCp,FV0812Al/SiCp,7075Al/SiCp的大尺寸复合材料.讨论了喷射共沉积过程中金属液体对SiC颗粒的捕获机理、喷射共沉积过程中的传热与凝固特征,分析了SiC颗粒的加入对金属液粒凝固的影响.     

网络广告中的法律问题及其对策

急速发展的网络广告 ,在传递给人们商品及服务信息的同时 ,自身也有许多需要不断完善的地方。网络广告中的主要法律问题有 :网络广告法律主体的定位以及由此导致的广告责任归责问题 ,网络广告中的隐蔽广告问题 ,电子邮件广告问题以及涉外广告的管理问题等。要解决这些问题应当从以下几个方面入手 :首先对网络广告定性 ,加快网络广告的立法工作 ,加强对ISP、ICP的管理 ,加大网络广告管理技术开发的投入和加强国际协作。只有这样 ,才能促使网络广告为人类的发展发挥更大的作用     

河西生态林业建设成就、问题及对策

论述了生态林及林业可持续发展的概念，总结了甘肃河西生态林业40多年建设成就，针对河生态林业可持续发展中所存在的问题，提出了生态林业可持续发展的对策。     

我国农村信息服务点建设中的问题与对策

农村信息服务点建设是我国农村信息化的重要抓手和落脚点,但由于管理体制等各种原因,导致我国农村信息化信息服务点建设还存在着一些问题,本文根据调查统计结果,对我国农村信息化信息服务点建设中的问题进行了系统分析,并提出了解决问题的对策和服务点建设的保障措施。