看麦娘和小麦竞争效应模型研究

通过田间试验与研究分析，建立了看麦娘和小麦密度与小麦产量的关系模型及由于竞争而引起的小麦产量损失模型．较准确地描述了看麦娘和小麦的竞争关系，预测由看麦娘竞争引起的小麦产量损失，模型参数具有实际的生物学意义．这对研究看麦娘的生态经济阈值，制定有效的看麦娘管理方案，建立高效的农业生态系统，具有重要的意义．     

基于单片机便携式打标机控制系统的设计

讨论了基于单片机控制的气动打标机,详细介绍了气动打标机的系统整体方案的设计,以及控制系统的实现。着重介绍了控制系统中的信息输出模块及相对应运动的实现。用脉冲的方式实现电磁阀的开断,以控制气动打标针头。通过对硬件电路的开发、制作,降低了成本,大大减小气动打标机的体积,提高了系统稳定性。实例证明效果良好。     

圆锯片锯割质量机理分析

从锯割表面质量评价因素入手，首次提出若干新概念，以此分析了锯片有关因素对锯割质量影响的机理。     

Efficacy of Sclerotinia minor for dandelion control: effect of dandelion accession, age and grass competition

Control of Taraxacum officinale (common dandelion) and other broad-leaved weeds in temperate turfgrass has been readily achieved with phenoxy herbicides. The herbicide option has been revoked through municipal and provincial legislation in many regions of Canada, necessitating alternative approaches. We examined the effects of dandelion accessions, age and grass competition on the performance of Sclerotinia minor (IMI 344141) as a biological control for dandelion in turfgrass. Disease symptoms were identical on all 14 different accessions of dandelion and the above- and below-ground biomass were reduced by 94% and 96%, respectively, with no difference among accessions. Foliar damage and dandelion mortality caused by S. minor was affected by plant age and the presence of grass competition. Dandelions of all ages were more severely affected by S. minor in the presence of grass competition. Grass competition had greater impact on foliar biomass, whereas the fungus had a greater impact on root biomass of newly established dandelions. In addition to competition for resources, we were hypothesised that the grass sward provides a microenvironment favouring the success of S. minor as a biological control agent of dandelion. Thus, proper management of the turfgrass environment may be complementary to the efficacy of S. minor as a biocontrol for dandelion.     

Competition and Control of Volunteer Jerusalem Artichoke in Various Crops

A major production constraint in Jerusalem artichoke ( Helianthus tuberosus L.) is caused by tubers which are not recovered at harvest. Such lost tubers raise a serious weed problem the following season. Winter wheat, oat, spring oilseed rape, sugarbeet, maize and ryegrass were grown in a field which had Jerusalem artichoke as the preceding crop in order to obtain information about their competitive ability and the efficacy of various control measurements against Jerusalem artichoke infestation. The Jerusalem artichoke treatments in these crops were: total control by regular hand weeding (TOC), mechanical/chemical control (MCC), and no control (NOC). Under the NOC treatment, Jerusalem artichoke infestation at harvest was variable among crops, with the number of shoots ranging from 9 to 25 m⁻² in oat and maize stands respectively. The number of Jerusalem artichoke shoots in the MCC plots was reduced by 50 to 99 % in oat and maize, respectively. The highest crop yields in each of the six species were realized under the TOC treatment. Insignificant yield reductions were observed in the NOC treatment of wheat, oat, rape and ryegrass. However, under this management yield reductions of 91 and 81 % occurred in sugarbeet and maize respectively. Depending on the preceding crop, 1–9 shoots m⁻² of Jerusalem artichoke were still recorded under the MCC plots in the following season. Consequently, for complete elimination of infestation, volunteers must be controlled in the second and probably in the third year following a Jerusalem artichoke crop.     

中国草食畜产品进口激增的动因分析

为识别影响中国草食畜产品进口快速增长的主导因素及其影响路径,基于2000~2019年的贸易数据,将价格因素和国内需求因素纳入同一研究框架,建立中国草食畜产品进口三元边际的联立方程模型。结果表明:中国草食畜产品进口增长主要由国内外价差驱动,经济发展和人口增长并未构成当前草食畜产品进口激增的动因;人均收入水平的提升通过价格边际促进草食畜产品进口量的增加;降低双边贸易成本有利于扩展草食畜产品进口的广度;双边自贸区的建立通过扩大贸易产品范围促进中国草食畜产品进口总量的增长。     

柳杉单木直径生长及形状指数模型

以ＶｏｎＢｅｒｔａｌａｎｆｆｙ生长理论为基础，用简单竞争指数建立柳杉人工林单木生长模型．从密度对于形影响的一般规律出发，分析简单竞争指数与形状指数的关系，建立形状指数模型，为立木材积的测算提供一条新的途径．     

论农业特色经济与农产品差异型竞争

在农业形成过剩经济的新形势下，本文在阐述差异型理论的基础上，分析了农业特色经济与农产品差异型竞争的关系，提出了选择主导产业、建设农产品加工工业园区、实施农业特色技术、农产品名牌战略及完善标准化制度六个实现农产品差异型竞争的对策。     

人工神经网络方法在林地经济区划中的应用

以反映林地区位的经济指标为因子,应用自组织竞争网络建立模型,经过不断的学习测试,以所得网络模拟仿真结果对福建省68个县(市)的林地进行经济区划,其结果分为4个区,分区结果基本反映了福建省林地利用现状,可为福建省的林业经济区划提供参考.     

河北旅游竞争影响因素分析

在研究旅游竞争有关理论的基础上分析了河北省旅游竞争的组成要素,指出河北应该从旅游资源、需求条件、旅游环境、周边市场4个方面来采取措施.对每一个组成要素进行了系统的分析,指出了存在的问题和竞争的焦点.总结出河北旅游发展应该把4个要素综合考虑,组成联动优势,共同打造河北的旅游竞争力.