二阶线性微分方程的非振动性

本文主要讨论了二阶齐次微分方秘AX″+BX′+CX=0的解的非振动性的充分条件     

富贵竹室内加工技术研究

 设杀菌剂瑞毒霉锰锌、营养液爱多收和促根剂吲哚丁酸不同浓度9个处理组合, 研究其对富贵竹去叶植株修口、顶侧芽生长及生根的影响。结果表明, 瑞毒霉锰锌3水平间修口效果、爱多收3水平间顶侧芽生长、吲哚丁酸3水平间根系生长的差异均极显著; 最佳处理组合, 小竹为0. 8 g/L^-1瑞毒霉锰锌+ 0. 15 mL/L^-1爱多收+ 30 mg/L^-1吲哚丁酸, 大竹为0. 8 g/L^-1瑞毒霉锰锌+ 0. 30 mL/L^-1爱多收+ 30 mg/L^-1吲哚丁酸。     

试验温室番茄营养液深液流栽培与研究

[目的]为营养液深液流技术在设施番茄高产优质栽培中的应用提供参考。[方法]以营养液深液流栽培为栽培方式,荷兰“百利”番茄为研究对象,通过温室无土栽培试验确定了适用于该栽培方式的营养液配方。[结果]适宜的营养液温度为22～32℃。营养生长期的适宜营养液浓度为1500～2500μS／cm,结果期的适宜营养液浓度为3000～4000μS／cm。2008年7月12日,对大栽培池中的番茄植株进行了第1次采摘,成熟果32个,挂果12个,成熟果单果重约130g,平均直径约65mm,最大直径约80mm。到2008年10月1日,大栽培池番茄植株累计采摘成熟果162个,挂果43个;其冠层面积约10m2,根茎直径为26．68mm,番茄长势良好。[结论]该试验为各种蔬菜、瓜果的无土栽培提供了新的技术支持。     

我国企业集团财务管理存在的问题及对策

企业产权不清晰、缺乏现代管理理念和统一的财务管理体系、资金运作不规范,缺乏行之有效的财务管理机制和执行预算不坚决等,是我国企业集团财务管理混乱的主要原因。更新管理理念,建立统一的财务管理体制,规范资金运作,强化资金管理是关键。     

《海洋水产研究》来稿中的问题分析

通过对《海洋水产研究》历年来稿档案的整理,分析了《海洋水产研究》来稿中存在的问题．提出了加强标准化、规范化等有关方面的作者教育,采解决这些问题,全面提高期刊质量。     

SULCMIS Ⅲ系统应用中遇到的问题及解决方法

主要讨论在图书管理系统SULCMISⅢ的使用过程中遇到的问题及解决方法,并提出一些系统目前未能解决的问题。     

日光温室秋冬茬水果彩椒营养液循环栽培技术

为更好探索秋冬茬盆栽彩椒栽培技术,昌平区农业技术推广站示范了椰糠盆栽彩椒营养液循环栽培生产模式。采用自动灌溉、合理的水肥配比、回流液回收利用及栽培管理技术,其中栽培技术内容包括品种选择、培育壮苗、定植及管理、授粉、植株调整、病虫害防治等,实现水肥配比合理化,节省人工;肥效较高,水肥循环利用率达90%,节水50%以上;使作物生长健壮、抗病力强,施药次数减少;667 m~2产量达5 570 kg,比传统栽培模式提高20%,社会、经济和生态效益显著。     

Varietal tolerance to Zinc deficiency in wheat and barley grown in chelatorbuffered nutrient solution and its effect on uptake of Cu,Fe, and Mn

Tolerance to zinc (Zn) deficiency was examined for three wheat (Triticum aestivum L.) and three barley (Hordeum vulgare L.) varieties grown in chelator‐buffered nutrient solution. Four indices were chosen to characterize tolerance to Zn deficiency: (1) relative shoot weight at low compared to high Zn supply (“Zn efficiency index”), (2) relative shoot to root ratio at low compared to high Zn supply, (3) total shoot uptake of Zn under deficient conditions, and (4) shoot dry weight under deficient conditions. Barley and wheat exhibited different tolerance to Zn deficiency, with barley being consistently more tolerant than wheat as assessed by all four indices. The tolerance to Zn deficiency in the barley varieties was in the order Thule=Tyra>Kinnan, and that of wheat in the order Bastian=Avle>Vinjett. The less tolerant varieties of both species accumulated more P in the shoots than the more tolerant varieties. For all varieties, the concentrations of Mn, Fe, Cu, and P in shoot tissue were negatively correlated with Zn supply. This antagonism was more pronounced for Mn and P than for Cu and Fe. Accumulation of Cu in barley roots was extremely high under Zn‐deficient conditions, an effect not so clearly indicated in wheat.     

我国公众环境知情权面临的困境及解决途径

环境知情权是公众享有的了解其生活、学习及工作等周围环境的基本权利,是参与环境管理的前提。应健全法律法规中环境知情权的相关规定,建立环境信息公开制度,扩大环境知情权的权力主体,明确企业的环境信息公开义务,建立环境知情权的诉讼机制,发挥民间环保组织的作用。     

Germinate to exterminate: chemical stimulation of Spongospora subterranea resting spore germination and its potential to diminish soil inoculum

Hoagland's solution (HS), a defined nutrient supplement for plants, has been previously reported to stimulate zoospore release from resting spores of the potato pathogen Spongospora subterranea f. sp. subterranea. This study obtained direct empirical evidence for an increase in zoospore release with HS treatment, and identified Fe‐EDTA as the stimulant component of HS. Stimulation of resting spores by HS and Fe‐EDTA resulted in greater and earlier zoospore release compared to a distilled water control, and in the presence of a susceptible tomato host plant resulted in enhanced root infection. Given the labile nature of S. subterranea zoospores, it was postulated that stimulation of premature release of zoospores from the dormant resting spores in absence of susceptible hosts could reduce soil inoculum levels. In two glasshouse trials in the absence of host plants, both Fe‐EDTA and HS soil treatments reduced S. subterranea soil inoculum levels, providing proof of concept for the ‘germinate to exterminate’ approach to inoculum management.