考虑公平关切的鲜活农产品供应链收益共享契约

研究收益共享契约下供应链成员具有公平关切时的鲜活农产品供应链协调问题。基于鲜活农产品的新鲜度和运输损耗因素,考虑供应链成员的公平关切特性,建立二级鲜活农产品供应链收益共享契约模型。进而分析了仅有零售商或供应商一方考虑公平关切,以及双方都考虑公平关切等不同情形下的供应链协调机制。分析结果表明,考虑供应链成员公平关切特性的情况下,当批发价满足一定条件时,收益共享契约能够使鲜活农产品供应链实现协调,且公平关切对供应链成员的效用有一定影响。最后运用算例对研究结果进行了验证。     

基于信号博弈的“公司+农户”模式中农产品质量研究

针对目前食品安全事件层出不穷的现状,本文利用信号博弈模型,讨论了“公司+农户”组织模式中导致农户发生机会主义行为的影响因素。通过对基本模型的分析,发现隐瞒生产信息所需要花费的粉饰成本是影响市场出现分离均衡或混同均衡的关键因素。通过对引入抽检后的扩展模型进行分析发现,如果外围市场处罚较小,并不能覆盖低质量农产品的利润与公司检验成本之和时,那么公司进行抽检的动力不大,或者即使抽检,市场中仍旧有违禁农产品的存在。最后讨论了在“公司+农户”模式中,如何提高农产品质量的方法和措施。     

区域资源禀赋、成本约束与农业生产效率测度

农业是我国基础产业,是保障粮食安全和经济发展的根本。根据经济发展战略要求和区域资源禀赋,合理发展区域农业,提升农业对区域资源使用效率和区域资源产业配置效益,形成区域农业高效发展和资源最优配置,是区域经济发展战略的重要内容。在柯布道格拉斯生产函数的基础上,利用随机前沿技术效率测度、产业投入产出分析、偏离-份额分析,构建农业产业生产效率的测度模型,探索地区农业产出的技术效率、资源利用效率和使用效率,为农业生产和区域资源配置提供参考。结果表明,大部分区域农业产出与资源禀赋未形成最佳匹配,应在大力提高农业对区域内资本资源、政府服务资源和劳动力资源使用效率的同时,鼓励过剩的资源在产业间和区域间进行适度转移,从低使用效益产业转移到高使用效益产业,从低产出弹性区域转移到高产出弹性效益区域。     

Thermal analysis of agricultural residues with application to production fuels

An important application of agricultural residues is as fuels for combustion processes. This paper shows how thermal analysis can be used for characterization of different kinds of cereals with a view to increasing efficiency in combustion processes. Results are in good agreement with those derived from standard ASTM methods.     

Analysis of three-component soil structures

Impregnated soil blocks were collected from a tillage trial at Condobolin, New South Wales. The object of the trial was to examine the consequences of performing the first tillage operation of the season on different dates. It was apparent that the soil broke up on tillage into the usual range of aggregate sizes plus a dust which was presumably composed of micro-aggregates. This was apparent on sections through the blocks which showed three components: voids, aggregates and dust.A statistical method for quantifying soil structure, developed earlier, is extended to include three components. Since this involves a large number of transition probabilities, two approximate simplified methods were tested. One of these, here called the ‘grey-state method’, could be widely applied in structure studies using automatic scanning devices where features brighter or darker than some adjustable threshold level are detected.The results show that the most recently tilled plot had the coarsest structure, but that the earlier two treatments were not significantly different from each other. The usual trend of decreasing aggregate size and decreasing porosity with increasing depth was not observed. Instead, there appeared to be some inversion of the usual layering of tilled soil which is attributed to the use of a motor-driven rod-weeder.     

分形维数排序农业生产结构的影响因素

自然资源、科学技术生产力、人口数量、市场需求、政府宏观调控5个因素是影响农业生产结构变动的主要因素,使用分形维数方法排序它们的影响力,以期为农业生产结构调整方案的制定,提供依据和参考.     

基于水足迹的嘉兴市农业产业结构优化模型

农业产业结构是决定农业用水效率的重要因素之一。相较于传统用水评价,基于水足迹的评价能更全面地反映水资源的过程消耗。在对嘉兴市农业蓝水、绿水及灰水足迹核算基础上,用农业水资源压力指数（AWSI）评估区域农业用水压力,构建了基于水足迹的农业产业结构优化模型,分析了节水型、均衡型和发展型3种农业产业结构调整情景。结果表明,嘉兴市农业水足迹以绿水为主,蓝水足迹、绿水足迹和灰水足迹的占比分别为11.6%,51.7%和36.8%,AWSI为0.45,存在较高的水资源压力;通过调整产业结构,3种目标情景下的农业水足迹及经济效益均实现了不同程度优化,AWSI分别降低4.54%,3.89%和0.74%,有效减轻区域水资源压力。研究表明,通过基于水足迹的农业产业结构调整,有效提高了区域集约化用水效率,减轻了用水压力。研究可为农业水资源管理决策提供参考。     

物理农业技术在现代农业基础科学与工程研究中的应用

在强调物理农业对现代农业发展重大意义的基础上,本文从物理因素对农作物繁育生长的促进作用和运用物理技术手段及采集农业环境信息两个方面叙述了物理农业技术在基础农业科学与农业工程研究领域中的应用与发展现状,并结合我国农业环境,提出了以先进的物理农业技术为切入点,重点发展物理农业的现代农业发展模式.     

流变学在国外农业工程中的应用

近年来许多发达国家广泛深入开展了关于农业物料流变学性质的研究.有关农业物料流变学性质的知识,对设计农业机械,加工处理农产品,以及农产品的质量评价等方面,可以提供许多重要的数据.本文对近年来国外这方面的研究工作进行了综述,同时简要介绍了食品流变学.      

Diatomaceous Earth for Arthropod Pest Control: Back to the Future

Nowadays, we are tackling various issues related to the overuse of synthetic insecticides. Growing concerns about biodiversity, animal and human welfare, and food security are pushing agriculture toward a more sustainable approach, and research is moving in this direction, looking for environmentally friendly alternatives to be adopted in Integrated Pest Management (IPM) protocols. In this regard, inert dusts, especially diatomaceous earths (DEs), hold a significant promise to prevent and control a wide range of arthropod pests. DEs are a type of naturally occurring soft siliceous sedimentary rock, consisting of the fossilized exoskeleton of unicellular algae, which are called diatoms. Mainly adopted for the control of stored product pests, DEs have found also their use against some household insects living in a dry environment, such as bed bugs, or insects of agricultural interest. In this article, we reported a comprehensive review of the use of DEs against different arthropod pest taxa, such as Acarina, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Ixodida, Lepidoptera, when applied either alone or in combination with other techniques. The mechanisms of action of DEs, their real-world applications, and challenges related to their adoption in IPM programs are critically reported.