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仓库通风降温网络的设计 总被引:3,自引:0,他引:3
收集整理了我国近50种不同仓容的房式仓尺寸数据,根据通风网络的布置关系,对途径比公式推导应用和仓库水平网络的设计方法进行了较为详尽的阐述。 相似文献
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为了寻找一种能同时考虑到植物种类在样方中出现与否和出现个体数两个因素在内的植物种间联结测定公式,文章提出一种描述植物种间联结关系的新公式I=1/N∑△Wdr,其中△Wdr=/n1-n2/n1+n2/N为样方数。新公式为一距离系数,取值区间为「0,1」,值越大,联结关系越小;反之,则相反。对新公式进行实例拟合,结果与实际相符。同时,对新公式和其它测定公式进行了比较,并讨论了新公式的检验问题以及与取样 相似文献
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粮层阻力计算公式的分析比较 总被引:1,自引:0,他引:1
本文汇集了粮层阻力的主要计算公式,指出各公式的来源、相互关系及使用范围,对这些公式的计算值进行了比较,分析了各因素对粮层阻力的影响,指出计算粮层阻力时应注意的问题。 相似文献
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本文从穗重与穗数的关系及经济产量与生物产量的关系两种不同的角度出发,分析了合宜密度问题,并提出了一些概括这些关系的经验公式。根据这些公式可以求出合宜密度范围。文中对不同肥力下的合宜密度、经济上合算的密度等问题,以及前人所提出的产量~密度函数关系进行了讨论。 相似文献
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袁瑞林 《农产品加工.学刊》2006,(4):60-61
一个粮机企业,坚持什么样的发展观,不仅会对企业的发展产生重大影响,而且还会对整个粮机行业产生深远的影响。因为,不同的发展观往往会导致企业有不同的发展结果。 相似文献
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芝麻花芽分化的序列性与提高结蒴途径的研究 总被引:1,自引:0,他引:1
研究结果表明,芝麻全株花芽分化为向顶式。第一花序着生节位主要由品种特性决定,植株叶片与花的发育具有同步序列性。可用公式测算出不同叶龄植株分化的总叶数,主花和侧花数。用植株展叶数可以预测花芽分化动态。 相似文献
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介绍了运用冷冻干燥技术进行速溶蛋花汤的加工,研究了生产工艺、特点以及影响产品质量的主要因素。试验表明,采用冷冻干燥技术加工的速溶蛋花汤,具有营养丰富、风味独特、方便快捷等特点。 相似文献
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DENG Zhao-jing 《保鲜与加工》2005,(1):153-156
A new definition of inertia,i.e. the momentum is the measuring of inertia of matter, is proposed. The article through and etc., subjects, the correctness of the new notion of inertia:The monentum is the measuring of inertia has been demonstrated, and the unsolved contradictions of the traditional definition of inetia. And the mass is the measuring of inertia has been revealed. 相似文献
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香蕉是热带亚热带发展中国家重要的粮食作物和碳水化合物来源。但近年来,香蕉生产受到严重的病虫危害。大多数香蕉栽培品种是三倍体,生长周期长,而且不孕。由于没有种子,给繁殖和育种带来一定的困难。遗传转化技术的发展为香蕉品种的改良提供了一种有效的手段。香蕉的遗传转化方法有电激法、基因枪法、农杆菌介导法等。农杆菌介导法的应用是香蕉品种改良的一个重大突破。香蕉遗传转化的外植体也发展到多种,有原生质体,胚性细胞悬浮系,分生组织,以及横切薄片等。近几年,随着分子生物学的发展,出现了转化效率更高,重复性更好的香蕉遗传转化技术。如农杆菌和基因枪结合法,离心辅助农杆菌介导法、真空渗透技术等。这些新技术新方法的出现,必将推动香蕉产业高速发展。 相似文献
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基于RS与GIS技术,利用景观生态学理论及景观格局指数对布尔津县土地利用现状进行定量分析。结果显示为:(1)布尔津县以草地、林地为主要景观类型,镶嵌着耕地、水域等景观类型。(2)四个分区(即高山区、丘陵区、平原区、荒漠区)的林地资源组成差异明显,耕地、居民、交通及工矿用地集中分布在丘陵区和平原区(3)从各项指数来看,高山区的多样性指数较低;平原区是受人文因素最多的区域,景观优势度低,各种土地利用类型比例差异不大,有利于生态可持续发展,但要合理的开发利用;荒漠区生态环境相对脆弱,要加强生态环境的保护与改善。通过该研究对布尔津县的土地利用现状作一个了解,为该县乃至整个地区的景观规划和可持续发展战略提供科学依据。 相似文献
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Efficiency of water use of early plantings of sunflower 总被引:4,自引:0,他引:4
M. Auxiliadora Soriano Francisco Orgaz Francisco J. Villalobos Elías Fereres 《European Journal of Agronomy》2004,21(4):465-476
Rain fed crop production in Mediterranean environments depends to a large extent on strategies that avoid the intense summer drought. Early plantings of sunflower have given consistently higher yields in such environments, but the basis for such yield increases has not been explored. We conducted two field experiments at Cordoba (Spain) to investigate the effects of an early and a late planting date on the components of water-limited crop productivity; namely, water use (T), water use efficiency (TE) and harvest index (HI) of sunflower. The results were generalized by simulating rain fed sunflower yields, under early (1 January) and late (15 March) plantings, for a 25-year period with the aid of a simulation model of the Ceres type (OILCROP-SUN) which has been validated in Cordoba. Experimental seed yields of early plantings in 1989 and 1996 were 2.0 and 3.0 t ha−1, while late plantings yields were 1.3 and 2.4 t ha−1, for the 2 years. Average simulated yields were 2.7 ± 1.1 and 1.9 ± 0.7 t ha−1 for early and late plantings, respectively. For the 2 years, T of early plantings was higher than that of late plantings, but the response of TE and HI to planting date was not the same in the two experiments. In the simulation exercise, T and TE of early plantings were consistently higher than those of late plantings, while there were no differences in the HI for the two planting dates. We conclude that early plantings of sunflower increase rain fed yields by increasing both T and TE, while the impact of planting date on HI very much depends on the crop water stress pattern, which is quite variable from year to year even in the predictable Mediterranean environment. 相似文献
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The cotyledon and hypocotyl of eight varieties of alfalfa( Medicago sativa L. )are used to study the effect of different cultivation procedures and genotypes on embryogenic callus and embryoid induction,plant development and transplant of alfalfa.The varieties of alfalfa with high embryoid induction rate and high differentiation rate are screened. A high frequency regeneration system for alfalfa tissue culture is established:which is benifical to the gene transformation of alfalfa. 相似文献
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Based on the relation between the incipient yield pressure and the limit of yielding in cylinder according to the elastic disabled rule, a laboratorial method of determining limit of yielding of material is designed and a set of experimental data were gained by the method. The incipient yield pressure of the cylinder is gained by analyzing the experimental data, and then the limit of yielding is gained. The laboratorial method has a good reliability as the experimental value has a little error to the theory value. It has a definite engineering signification and theory value to research the mechanical capability of material and the disabled rule of high pressure vessel. 相似文献