辽宁省农业机械化发展水平的评价与分析

科学地评价农业机械化在农业现代化生产中的地位与作用,研究不同地区农业机械化发展水平及发展速度,是农业机械化宏观管理的重要内容。通过对辽宁省农业机械化发展情况的调查研究,应用聚类分析理论与方法,对辽宁省14个市(地)区进行了系统分类处理,定量与定性分析相结合,对不同类区的农机化发展水平进行了分析与评价。     

基于对数相似度约束Otsu的自然场景病害果实图像分割

针对自然场景下,由于复杂背景以及多变环境,水果病害果实图像分割难的问题,提出了一种基于对数相似度约束Otsu和水平集活动轮廓的近椭圆形病害果实图像分割方法。考虑背景的复杂多变,提出对数相似度约束Otsu分割来区分病害果实与背景;由于水平集活动轮廓模型的局部最优性,提出采用自适应膨胀系数的改进距离规则水平集活动轮廓模型来精确演化轮廓。先对病害果实区域样本的颜色进行混合高斯建模,获得整个病害果实图像与样本模型的对数相似度;对对数相似度进行约束Otsu阈值分割以及形态学滤波;采用最小二乘法对滤波后的曲线轮廓进行椭圆拟合,对拟合后的椭圆采用自适应膨胀系数的距离规则水平集活动轮廓演化,得到病害果实完整轮廓。对18个不同场景的病害果实进行分割,平均误判率和漏判率分别为1.77%和1.6%,实验结果表明,该方法可以从复杂自然场景图像中分割出病害果实。     

Recruitment of sympatric vendace (Coregonus albula) and whitefish (C. lavaretus) is affected by different environmental factors

Vendace and whitefish in Lake Osensjøen (boreal south‐east Norway) were studied by means of gillnet test fishing (1976–2013) and hydro acoustic acquisition (1986–2011). Vendace increased in number between 1998 and 2009 while growth and size at maturity decreased. The relative density of whitefish decreased in the pelagic habitat, whereas growth and size remained the same. Both species exhibited varying year‐class strength. Whereas strong year‐classes of both species became less frequent after 1980 than before this, this seemed to change after 2000, especially for vendace. Generalised additive models suggested a strong positive relationship between July/August mean air temperature and year‐class strength of both vendace and whitefish. Whitefish recruitment was also negatively affected by the new regulation regime implemented since 1981, and positively correlated with water level after hatching and by late ice off. The reason for the diverging impacts of environmental factors on the two species may be that vendace spawn in deeper waters that whitefish do. The results indicate that increasing summer temperatures benefit recruitment of both species, whereas low water level and early ice off will harm whitefish recruitment. Both trends are caused by climate warming. It may be speculated that increased density of the specialised plankton feeding vendace may affect the algal community through increased predation on herbivorous zooplankton and potentially affect the trophic state of the lake.     

Potential for organic Chilean wine

Abstract

The potential for extending organic wine production in Chile is discussed in relation to its history and present situation. The main objective is to present an overview of the production of organic wine in Chile, its certification, and national and international markets. During the wine harvesting season in March and April 2006, the authors visited and interviewed staff at four Chilean organic wineries. The wineries were all situated in the wine-producing centre of the country and were of variable sizes. One of the certification bodies in Chile was also interviewed. In addition to the field studies and interviews in Chile, various written information has been used. Second to Argentina, Chile is the country that produces most wine in Latin America. Vineyards cover a total of 110 000 hectares of the country's two million hectares of arable land. A study carried out in 2005 showed that 2000 hectares (almost 2%) of vineyards are organically cultivated. The organic production is operated by 32 different companies, which produce organic wine mainly for exportation to the international market. In Chile, the number of certified organic wine producers has increased in recent years in a trend directed by international demand and possible competitive advantages for Chilean wines. In order for a wine to be called ‘organic’ or ‘wine made from organically grown grapes’, the cultivation and final product must be approved by a certification company. In Chile there are three main active certification bodies; one national (Certificadora Chile Orgánico, CCO) and two international (the Swiss company IMO and the German company BCS). The study reveals a country with innovation and energy but facing strong pressures from the international market and its jungle of laws and directives, and the differing prestige of different certifications and labels. Chile as a wine-producing country has many competitors, and the production of organic wine could be a way to find diversity and exploit new market ground where environmental consideration concerns and sustainability are important targets.     

凤冈县三资转换的成效与困境及对策

由资源转换成资产再转换为资本的做法简称三资转换。贵州省凤冈县充分利用农村产权制度改革试点机会,积极探索三资转换工作,在激发农村发展活力、有效解决三农问题方面产生了积极的影响。为进一步推动凤冈县的三资转换工作提供参考,在凤冈县实地调查的基础上,对三资转换的路径和成效进行了归纳总结,对三资转换工作面临的困境进行了探讨,同时提出了三资转换的对策。     

农民创业过程中基层政府与农民关系的探究

在国家政策的积极支持下,现在农民创业的热情非常高涨,也有很多成功的案例,但不少基层政府没有很好地理解政策的精神,导致创业过程中农民与基层政府的关系出现了偏差,使得农民不相信基层政府,甚至对有些干部非常反感。本文分析了关系出现偏差的原因并提出了完善的措施。     

铁元素对农田人参丙二醛含量及防御酶活性的影响

[目的]研究Fe2＋对人参（Panax ginseng Meyer）叶中防御酶活性和丙二醛（MDA）含量的影响。[方法]采用叶面供Fe2＋的方法。试验共设5个处理,Fe2＋浓度分别为：0（对照）、0.005%、0.050%、0.500%、2.000%。[结果]随着供Fe2＋水平的升高,MDA含量先降低后升高,过氧化物酶（POD）活性呈持续上升趋势,过氧化氢酶（CAT）活性先升高后降低,超氧化物歧化酶（SOD）活性呈先升高后降低再升高的趋势。[结论]从生理角度揭示了铁元素在人参生长发育中的作用机理,为人参的合理施肥提供理论参考。     

企业人力资本投资风险的理论分析与对策探讨

企业是以追逐利润为目的的经济组织,为了提高员工的生产能力,提高经济效益,一般都会对员工进行人力资本投资。企业人力资本投资具有与政府公共人力资本投资和个人人力资本投资不同的特点,主要表现为追逐利润动机明确、出资主体较单一、投资方式较简单、投资风险大。造成企业人力资本投资风险的因素是多方面的,企业必须采取一定的对策措施减少人力资本投资收益的不确定因素,降低投资风险。     

供氮水平对田间桑树叶片产量及其生理特性的影响

为了探寻龙桑一号的适宜施氮量,从而指导桑农科学施用氮肥,以桑树品种龙桑一号为试验材料,在大田条件下研究了不同供氮(纯氮)水平(0、48.3、96.6、144.9、193.2和241.5kg.hm-2)对桑树叶片产量及其生理特性的影响情况。结果表明:当施氮量为0～193.2kg.hm-2时,桑树单株枝条数、单枝叶片数、单叶面积、单叶质量和单株产叶量均随供氮水平的增加而增加,而当施氮量达到241.5kg.hm-2时,桑树单叶面积、叶片质量和单株产叶量反而有所降低;施氮量在0～144.9kg.hm-2范围内,桑树叶片中的全氮(N)和全磷(P)含量均随施氮量的增加而提高,而当施氮量超过144.9kg.hm-2时,叶片中的全氮和全磷含量随着施氮量的增加反而有所降低,这说明施氮量过高反而降低了桑树对N和P的吸收;随着供氮水平的增加,桑树叶片中的叶绿素含量、可溶性蛋白和可溶性糖含量均随施氮量的增加而增加。从氮肥对桑树产叶量及其生理特性的影响情况来看,桑树品种龙桑一号田间的最佳施氮量为144.9～193.2kg.hm-2。     

禁牧休牧监管立法的分析与探讨

禁牧休牧已成为保护和培育生态植被的一种主要方式,是遏制草原荒漠化的有效手段。相对于禁牧休牧的制度需求,其监管立法却存在诸多问题需要完善,本文从立法层级、监管体制、法律责任等方面分析了禁牧休牧监管立法中存在的问题,着重论述其完善途径,并提出了相应的立法建议。