基于云计算的数字图书馆平台架构设计

数字图书馆是随着图书情报学、网络技术、存储技术、多媒体处理技术和数据挖掘技术等发展而出现的产物,云计算的出现和发展将给数字图书馆的功能和应用服务带来很大的变革。在分析数字图书馆平台所需要解决问题的基础上,给出了基于云计算的数字图书馆平台目标系统模型,较为详细地介绍了三层结构（模型数据层、控制算法层和表现应用层）的数字图书馆平台框架设计。     

日光温室内南北方向黄瓜群体结构参数分析

为研究日光温室内南北方向和垂直方向作物群体结构参数,观测了日光温室内南北方向北、中、南3段及垂直方向各层次的黄瓜群体结构参数,结果表明,在整个生育期平均叶倾角都是北段大于中段和南段,叶片分布频率偏南的趋势也是北段最大,中段次之,南段最低;在垂直方向0~40 cm高度冠层的平均叶倾角最大、叶片分布频率偏南段最低,其他各高度冠层叶片叶角之间无明显规律,但总体趋势均为植株南面叶倾角和叶片分布频率均大于植株北面;黄瓜叶面积系数和株高由北向南逐渐升高,各段不同层次叶面积密度也存在一定差异。试验结果说明,温室南北方向各段黄瓜群体参数结构明显不同,垂直方向各层黄瓜群体结构参数具有一定差异性。     

一种关联规则算法在农业网站日志分析中的应用

通过访问农业专家在线系统网站的用户行为,运用Web挖掘理论和方法对农业网站日志进行关联规则和链接分析,将关联规则算法用于农业网站日志分析中,用户在同一次访问中访问不同栏目的相关性、用户在一段时间内频繁访问页面及访问栏目间的最短访问路径,提高了咨询服务效果,保证了农业专家在线系统信息资源的有效利用。     

立体花坛在城市绿化中的应用研究

介绍了立体花坛的特点、功能、形式及其发展趋势,从造型、植物取材、色彩、文化内涵、景观状态、规模、应用范围等各方面阐述了立体花坛的应用现状,同时总结了立体花坛在艺术设计、结构造型、填充物及绑扎技术、植物配置与栽植、种植工艺以及养护管理等方面的经验,以为今后在国内的城市绿化中较好地应用立体花坛起到借鉴作用。     

关于生态设计与风景园林的思考

在城市环境日益恶化的今天,生态设计的概念越来越吸引设计者和决策者的注意力。任何与生态过程相协调,尽量使其对环境的破坏影响达到最小的设计形式都称为生态设计。景观的生态设计反映了人类的一个新的梦想,一种新的美学观、世界观和价值观:人与自然地真正合作与友爱的关系。总结了生态设计的内涵,并分析景观生态设计的思想及原则。     

“学科交叉融合 注重个性设计”引导二年级建筑设计启蒙

建筑设计是建筑学专业的主干课程,贯穿于建筑学专业的5年教学环节。根据建筑学二年级教学目标、要求和学生特点,以案例＂幼儿园设计＂教学实验为例,采用学科交叉融合、注重个性设计的教学思路,构建了以学生构思为主导,多学科为指导,模型为辅助,任务要求为方向的教学体系,提出了二年级建筑设计教学的新思路。     

浅谈建筑施工的协调管理

建筑施工中各专业之间协调与配合,直接关系到工程的质量与品质,本文分析了建筑施工中各专业协调管理的重要性及产生问题的原因,并探讨了项目经理如何做好工程项目建设的组织与协调工作,从而使工程建设项目的质量目标、进度目标、费用目标得以实现。     

城市住区景观环境质量使用后评价体系研究和应用

文章基于层次分析法和模糊评价法初步建立了城市住区景观环境使用后评价的指标体系,并结合水木花都小区的案例进行了应用,以期引起公众对我国园林项目中开展POE的重视和研究。       

论秦皇岛园林的文化特色

园林文化是园林艺术的精华所在。秦皇岛经过了2000多年的历史,积累了丰富的文化内涵。秦皇岛园林作为秦皇岛文化的载体,呈现了鲜明的文化特色。秦皇岛园林文化不仅表现在以丰富的传统文化、滨海文化为主体,而且融入了体育奥运文化、生态文化和高科技文化,具有特征突出的多元文化特色。在保护和开发秦皇岛园林文化方面应突出其传统文化和滨海文化的主体特征,更多地体现体育精神,加强秦皇岛生态园林建设和进一步加大现代科技在园林中的应用。     

A new integrated CFD modelling approach towards air-assisted orchard spraying. Part I. Model development and effect of wind speed and direction on sprayer airflow

The current trend in modelling flow phenomena within trees such as in orchards follows the assumption of the space occupied by the trees as a porous and horizontally homogeneous medium to avoid the flow details associated with the individual plants. This being sufficient at a larger field or regional scale much has to be done at a plant scale to analyse the flow details within the plant and its elements especially for sensitive agricultural operations such as spraying. This article presents an integrated 3D computational fluid dynamics (CFD) model of airflow from a two-fan air-assisted cross-flow orchard sprayer through non-leafed orchard pear trees of 3 m average height. In this model the effect of the solid part of the canopy on airflow was modelled by directly introducing the actual 3D architecture of the canopy into the CFD model. The effect of small canopy parts, such as very short and thin branches and flowers that were not incorporated in the geometrical model, on airflow was simulated by introducing source-sink terms in the Reynolds averaged Navier-Stokes (RANS) momentum and k-? turbulence equations in a sub-domain created around the branches. This model was implemented in a CFD code of ANSYS-CFX-11.0 (ANSYS, Inc., Canonsburg, PA, USA). In this work it was possible to link the real 3D architecture of pear canopy into a CFD code of CFX. The model was able to capture the local effects of the canopy and its parts on wind and sprayer airflow directly by inserting the tree structure into the model which gave realistic results. The model showed that within the injection region of the sprayer there was an average reduction of the jet velocity by 1 m s⁻¹ for a distance of 2.3 m from the sprayer outlet due to the presence of leafless pear canopy. This reduction was variable at different vertical positions due to the difference in the canopy density. Maximal effect of the canopy was observed in the middle height of the trees between 0.25 m and 2.5 m which is the denser region with a bunch of several branches. The maximum velocity difference observed between these two positions was 1.35 m s⁻¹ at 1.75 m height. Thus, regions of high and low air velocity zones of the sprayer due to the variable branch density of the pear tree were predicted. The effects of wind speed and direction on the air jet from the sprayer were investigated using the model. For a cross- (direction of 90°) wind speed of 5 m s⁻¹ there was about 2 m s⁻¹ reduction in the sprayer jet velocity at the jet centre and 0.5 m horizontal shift of the jet centre towards the wind direction. Generally there was a decrease in the jet velocity with increasing cross-wind and decreasing wind direction with respect to the jet direction.