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江西玉米生产的调查研究 总被引:1,自引:0,他引:1
本文通过6个县的调查研究,提出了江西发展玉米生产的四项措施:1.春玉米较宜旱地、夏玉米较宜山区、秋玉米较宜水田的玉米布局;2.适当早播、早管早发、增施肥料、合理灌排的栽培技术;3.农户种玉米养猪的的种养结合方式;4.开展综合开发。 相似文献
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分析了优质蛋白玉米的经济利用价值,生产现状,提出了进一步发展优质蛋白玉米的对策,认为加大宣传力度,创立优质优价的新机制,实行种养结合,强化种子质量管理等有助于优质蛋白玉米的进一步发展。 相似文献
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一、试验目的 通过试验,鉴定供试品种的产量、营养品质、抗逆性及地区适应性,客观评价品种特性和生产利用价值,选择适合于北京地区畜牧业利用的高产优质青贮玉米品种,为种养快速发展服务. 二、材料和方法 品种主要选自当前生产中利用及各科研院校、育种部门推荐的青贮青饲玉米品种.结合2001年试验结果,选择18个玉米品种进一步品种筛选. 相似文献
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正"要加快发展草牧业,支持青贮玉米和苜蓿等饲草料种植,开展粮改饲和种养结合模式试点,促进粮食、经济作物、饲草料三元种植结构协调发展"。——2015年中央一号文件种养结合型调整。重点是粮饲兼顾,调减籽粒玉米、发展青贮玉米和苜蓿,以养定种,把"粮仓"变为"粮仓"+"肉库"+"奶罐"。 相似文献
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本试验以菜豆品种先行者为试材,采用32孔、50孔两种规格穴盘,设置10、15、20、25 d等4个苗龄段,通过研究不同穴盘规格和苗龄对菜豆性状及产量的影响,筛选出适合菜豆育苗的穴盘规格和适宜的苗龄。结果表明:穴盘育苗的营养面积增大,菜豆产量随之增加,25 d苗龄条件下,32孔穴盘的前期产量和总产量均显著高于50孔穴盘;随着苗龄的增长,菜豆的前期产量和总产量呈增加趋势,其中25 d苗龄的产量显著高于其他苗龄。综合上述各项指标,菜豆育苗阶段,10 d苗龄可选用32孔、50孔穴盘,15 d以上秧苗选用32孔穴盘为宜。 相似文献
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氮素作为重要的营养元素,限制着小麦的生长发育和经济产量,筛选和培育耐低氮小麦品种是提高氮素利用率、降低生产成本的有效途径。以118份不同基因型小麦为材料,在低氮(0.1 mmol·L-1)和正常氮(5 mmol·L-1)条件下苗期水培,测定根干重、茎叶干重、根冠比、植株干重、最大根长、初生根数和二级初生根数等相关指标,采用模糊隶属函数法、主成分分析以及聚类分析法综合评价小麦品种的耐低氮性。结果表明,在低氮胁迫下小麦幼苗的根干重、根冠比和初生根数目显著提高,茎叶干重、植株干重和最大根长不同程度的降低,7个苗期性状指标在两个氮水平下均存在显著性差异。主成分分析提取3个主成分,贡献率分别为 43.575%、22.904%和17.873%,累积贡献率达 84.351%。以耐低氮性综合评价D值进行聚类分析,将118份小麦品种划分为强耐低氮型、耐低氮型、中间型、较敏感型和敏感型5类。筛选出3份耐低氮型小麦(齐大195、金丰7183和天民198)和2份强耐低氮型小麦(山农0917和鲁麦8号)。不同小麦品种的耐低氮机制不同,研究结果为小麦耐低氮品种的选育提供理论依据和材料基础。 相似文献
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ICP-OES法同时测定果蔬中铅、砷、镉、铬、铜、锡含量 总被引:2,自引:0,他引:2
果蔬样品经混酸消化后,控制一定的酸度,定容后应用等离子体发射光谱法(ICP-OES)对果蔬中铅、砷、镉、铬、铜、锡六种有害重金属进行测定,研究了分析测定条件,方法简单快速。测定结果表明,五种元素的加标平均回收率在91.0%~107%之间。其RSD均小于3.5%。按该方法进行处理及测定铅、砷、镉、铬、铜、锡,在选择的测定条件下最低检出限分别为0.0006 mg/kg、0.0003 mg/kg、0.00003 mg/kg、0.00005 mg/kg、0.00003 mg/kg、0.0006 mg/kg。 相似文献
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Segregation of form, color, movement, and depth: anatomy, physiology, and perception 总被引:63,自引:0,他引:63
Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties. 相似文献
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Zhang M Fang S Zakhidov AA Lee SB Aliev AE Williams CD Atkinson KR Baughman RH 《Science (New York, N.Y.)》2005,309(5738):1215-1219
Individual carbon nanotubes are like minute bits of string, and many trillions of these invisible strings must be assembled to make useful macroscopic articles. We demonstrated such assembly at rates above 7 meters per minute by cooperatively rotating carbon nanotubes in vertically oriented nanotube arrays (forests) and made 5-centimeter-wide, meter-long transparent sheets. These self-supporting nanotube sheets are initially formed as a highly anisotropic electronically conducting aerogel that can be densified into strong sheets that are as thin as 50 nanometers. The measured gravimetric strength of orthogonally oriented sheet arrays exceeds that of sheets of high-strength steel. These nanotube sheets have been used in laboratory demonstrations for the microwave bonding of plastics and for making transparent, highly elastomeric electrodes; planar sources of polarized broad-band radiation; conducting appliqués; and flexible organic light-emitting diodes. 相似文献
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