共查询到20条相似文献，搜索用时 53 毫秒
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提出一种利用L系统建立植物拓扑结构原型,利用规则曲线、三次样条曲线、B样条曲线对植物参数进行控制的虚拟植物形态控制方法,以达到直观虚拟植物控制形态的目的.重点分析了参数曲线与植物参数的关系,建立了植物长度类参数、角度类参数、颜色类参数与参数曲线的关联模型.试验表明,该方法简单直观,生成的图形真实感强,适用于虚拟植物的模拟研究. 相似文献
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植物细胞分裂素是一种植物生长调节剂，它是一类具有腺嘌呤环结构的植物体内激动素。能够刺激植物细胞分裂，诱导芽的生成并促进其生长，促进叶绿素形成，并能增加植物的含糖量及生物碱，增强光合作用，提高植物免疫力，改良农产品质量，提高植物的抗病性及抗寒、抗旱性，防止植物早衰及花果脱落，粮食作物可增产10％～15％，蔬菜、瓜果等经济作物增产15％-20％，并对番茄、黄瓜、烟草病毒病有很好防效。 相似文献
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西湖城市植物历史景观文化是杭州生态历史植物文化的完美浓缩,与杭州现代城市的生态历史植物文化景观发展有着紧密联系,是杭州城市植物文化景观的典型代表.人们对我国园林景观的艺术审美评价,在很多极大程度上直接决定了我国园林景观中的各种植物园林景观艺术营造的成功与否,因其植物作为我国园林景观的主要艺术构成部分要素起着决定性的作用... 相似文献
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兰科植物的观赏除了单体美,对于自然状态下的兰科植物与植物群落的搭配也能体现出和谐的整体美,本文根据兰科植物的色彩和形态等特征,对兰科植物的植物配置模式进行探讨,并提出未来兰科植物专类园的创新设计的可能性。 相似文献
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随着社会的快速发展,人们的思想开始从物质需求转向对高质量的精神生活与健康的生活方式的追求,越来越多的人拥有了"自然缺失症",这使人们对生存环境的要求越来越高。园林可以改善人们的生活环境,给人以美的生活感受,植物配置和植物造景是园林设计中的重要环节。文章通过对文献的研究,对相关概念进行阐述,对作用与原则以及存在的问题进行分析,期望在景观设计中运用生态学原理进行科学合理的植物规划,使植物与植物之间、人与环境之间更加和谐。 相似文献
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本文主要综述了超富集植物的概念以及铜超富集植物的研究进展,对超富集植物存在的问题提出建议,旨在为以后铜矿区废弃地的植物修复研究提供参考。 相似文献
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为了将刺篱植物替代金属隔离栅应用于云南省高速公路,从刺篱植物自身隔离性能、刺篱植物抗逆性能和刺篱植物景观效应等3个方面,提出了由13个评价指标组成的云南省高速公路隔离用刺篱植物筛选评价指标体系,并通过构建综合评价模型,对16种刺篱植物进行评价,评价认为:苦刺、马缨丹、围涎刺、叶子花综合隔离效果较好。 相似文献
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Overland water and salt flows in a set of rice paddies 总被引：1，自引：0，他引：1
E. Playn O. Prez-Coveta A. Martínez-Cob J. Herrero P. García-Navarro B. Latorre P. Brufau J. Garcs 《Agricultural Water Management》2008,95(6):645-658
Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m−1) and an infiltration rate of 5.8 mm day−1. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day−1), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day−1 was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration. 相似文献
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车用发动机润滑油失效规律与更换周期研究 总被引：7，自引：0，他引：7
研究在正常使用条件下１０Ｗ／３０－ＱＣ级润滑油用于某型车用发动机时所表现的失效规律,确认期服从两参数Ｗｅｉｂｕｌｌ分布,并给出分布的尺度参数η和形状参数ｍ之最佳线性无偏估计（ＢＬＵＥ）同时,还为定量分析,计算车用发动机润滑油的使用可靠性和合理确定其更换周期提供了一套可供借鉴的方法,并给出了具体的计算实例。 相似文献
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赵国杰 《农业机械化与电气化》2011,(4):106-107
乡（镇）农技推广体系是农业发展的关键。介绍朝阳市农业技术推广体系的现状,针对目前体制及运行机制、服务手段等方面存在的问题,提出适合朝阳市乡（镇）农技推广体系改革与发展的对策,以期对全省农技推广体系改革和发展起到一些借鉴作用。 相似文献
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苑庆刚 《农业机械化与电气化》2010,(3):52-54
草莓果味酸甜爽口,营养价值高,为人们所喜爱的应市鲜果之一。由于草莓易受损伤和微生物侵染,因此其采收、贮藏过程极为重要。介绍草莓采收过程中的注意事项以及11种贮藏保鲜技术的实施步骤和操作方法,推介9种加工方式,为草莓产业化提供技术支持。 相似文献
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瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。 相似文献
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对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。 相似文献
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对《种子法》存在问题的探讨 总被引：1，自引：0，他引：1
李鹏 《农业机械化与电气化》2011,(6):129-130
《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。 相似文献
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About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered. 相似文献
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在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。 相似文献