园林本科专业人才培养模式现状分析

从知识结构、教学资源、人才规格特征等方面,分析现行园林本科专业人才培养模式,认为园林学是由基础核心课程与专业骨干课程组合,形成不同的专业方向,集合构成了一级学科的主体特征。     

爪式粉碎机旋转噪声分离与提取的研究

本文以FFC—23A型爪式粉碎机为样机，利用现代声学测试分析手段对其工作时定齿盘内、外圈齿与相应动齿相掠过所产生的旋转噪声进行了试验分离研究，从而得出了爪式粉碎机旋转噪声的主要成分源自工作中外圈定齿与其相互作用的动齿所产生的噪声。     

蜂巢温湿度数据采集与分析处理系统*

 系统将数据采集与数据分析处理相结合，通过串行接口，实现对单片机发送的温度和湿度数据的采集，对接收的数据进行检测与分析，将采集到的数据按不同传感器号区别开来，实现在远端的PC机上存储、查询、制图、打印和显示等功能。     

小麦栽培管理动态知识模型的构建与检验

 将系统分析方法和数学建模技术应用于小麦管理知识表达体系，通过解析和提炼小麦生育及管理指标与环境因子及生产水平之间的基础性关系和定量化算法，创建了小麦管理动态知识模型WheatKnow；充分利用软构件的技术特点，在Visual C++和Visual Basic平台上研制了数字化和组件化小麦管理动态知识模型系统，实现了播前栽培方案的设计和产中适宜调控指标动态的预测2大功能。其中，播前栽培方案包括产量目标、适宜品种、播期、基本苗及播种量、肥料运筹和水分管理；产中调控指标包括适宜生育期、穗分化进程、生长指标、源库指标和营养指标动态。利用不同生态点、不同品种、不同土壤等资料及大田对比试验对所建知识模型进行实例分析和检验的结果表明，所提出的小麦管理动态知识模型总体上具有较好的广适性和决策性。本研究克服了传统作物栽培模式与专家系统地域性强和广适性弱的不足，从而为实现作物栽培管理的精确化和数字化奠定了基础。     

基于无线传感器网络的土壤信息采集系统

针对土壤信息采集的需要,提出了把无线传感器应用于土壤信息采集的思路,研究设计了一套基于无线传感器网络的土壤信息采集系统。节点设计采用低功耗MSP430单片机和CC2430 ZigBee无线射频芯片完成,可采集土壤温度、湿度和土壤含水率。系统网关设计基于ARM7系列S3C4480X、GPRS模块SIM100,搭建了农田中...     

土地征用中多方主体的角色分析

在土地征用中,地方政府起主导作用,村委会扮演对上负责、为民服务的双重角色,农民面对眼前的补偿及日后生活陷入矛盾境地。基于维护各自利益的立场,各方主体出现角色偏离的行为,需要各方都摆正角色。     

Public perceptions of natural disturbance in Canada’s national parks: The case of the mountain pine beetle (Dendroctonus ponderosae Hopkins)

Since the 1990s, the mountain pine beetle (MPB) population has exploded in western Canada. In national parks, MPB has the potential to impact visual quality and safety of visitors, and to spread beyond park boundaries to the industrial forest landbase. Control measures have been initiated in some parks to lessen these impacts. A study was undertaken to examine public attitudes, knowledge, issue salience, and management preferences for MPB in Banff and Kootenay national parks. Data were collected by mail survey in 2003 from 1385 residents living in or near the parks. MPB was an important issue for the majority of respondents and they had low knowledge of MPB, expressed negative attitudes towards it, and supported measures to control it. Preferred control measures included those directed at the current infestation. Proactive approaches in uninfested forests were generally not supported. Issue salience and knowledge were the best predictors of attitudes toward the MPB. Attitudes were the best predictors of support for no intervention in beetle infestations in national parks. Management implications include the lack of knowledge and support for natural disturbance and ecological integrity policies in national parks.     

Response of cotton root growth and yield to root restriction under various water and nitrogen regimes

Water and nitrogen (N) are two major factors limiting cotton growth and yield. The ability of plants to absorb water and nutrients is closely related to the size of the root system and the rooting space. Better understanding of the physiological mechanisms by which cotton (Gossypium hirsutum L.) adapts to water and N supply when rooting volume is restricted would be useful for improving cotton yield. In this study, cotton was grown in soil columns to control rooting depth to either 60 cm (root‐restriction treatment) or 120 cm (no‐root‐restriction treatment). Four water–N combinations were applied to the plants: (1) deficit irrigation and no N fertilizer (W₀N₀), (2) deficit irrigation and moderate N fertilizer rate (W₀N₁), (3) moderate irrigation and no N fertilizer (W₁N₀), and (4) moderate irrigation and moderate N fertilizer rate (W₁N₁). Results revealed that root restriction reduced root length density (RLD), root volume density (RVD), root mass density (RMD), superoxide dismutase (SOD) activity, nitrate reductase (NR) activity, total plant biomass, and root : shoot ratio. In contrast, root restriction increased aboveground biomass and yield. The RLD, RVD, RMD, and root : shoot ratio decreased in the order W₀N₀ > W₁N₀ > W₀N₁ > W₁N₁ in both the root‐restriction and no‐root‐restriction treatments. However, the opposite order (i.e., W₁N₁ > W₀N₁ > W₁N₀ > W₀N₀) was observed for SOD activity, NR activity, aboveground biomass, and seed yield. Our results suggest that, when N and water supplies are adequate, root restriction increases both root activity and the availability of photosynthates to aboveground plant parts. This increases shoot growth, the shoot : root ratio, and yield.     

农业大数据的获取与利用

大数据的发展日新月异,已经深入到包括农业在内的各个行业.因此,农业大数据作为农业信息化的发展趋势,是新一代信息技术的集中反映,是一个具有无穷潜力的新兴科技产业发展方向.该研究结合农业大数据的基本特征与产业链构成,介绍了农业大数据的基本概念,基于相关农业信息平台、农业数据库等渠道,阐释了农业大数据的获取方式,并从良种培育、精准种植、农业生态环境监测、天气预测等维度对农业大数据的利用进行探讨,以正确面对农业大数据面临的机遇与挑战,为农业的发展、创新奠定基础.     

知识溢出视角下沼气合作开发中政府补偿政策设计

引用政府补偿政策干预对企业与农户合作模式进行重复博弈分析。针对政府干预下的企业与农户行为特征,借用知识溢出模型得出相应的效用函数,并通过均衡分析,得出政府促进企业与农户合作的策略:第一,达成合作的策略需要保障贴现因子在特定的区间内波动;第二,对于政府补偿政策而言,需要增强农户与企业沼气能源使用率,减小博弈双方知识储备差异的,通过政府资金支持和技术支持增强沼气能源技术的追赶能力,同时合理的规划养殖企业和农户之间地理位置的距离等方式保证合作进行。