399 resultados para 1254
Resumo:
En la época de postrera 2005, se realizó la evaluación de 9 genotipos de arroz procedentes de Colombia y una variedad comercial de Nicaragua (INTA DORADO). El experimento se realizó en la localidad de Paso Real, de San Isidro, Matagalpa, ubicado a los 12º54 ́ latitud norte y 86º11 ́ longitud oeste, a una altura de 457 msnm. La finalidad del ensayo fue identificar líneas con buen rendim iento de grano, calidad molinera, tolerancia a enfermedades y buena adaptabilidad a las condiciones de riego. El diseño experimental fue el de bloque completo al azar (BCA) con 10 tratamientos y 4 repeti ciones. Utilizándose ANDEVA y separación de media SNK ( ∞ =0.05). En la mayoría de las variables evaluadas se determino que existe efecto significativo y altamente significativo entre los diferent es tratamientos. Los principales resultados evidencian que los genotipos L-9, L-39, POB L1-34, POBL 3- 13, alcanzaron los mayores rendimie ntos con producciones de 5,312, 5,193, 5,082.50, 5,044 kg ha -1 respectivamente superando al testigo INTA DORADO que obtuvo el menor rendimiento con 3,506 kg ha -1 . Los componentes del rendimiento: núme ro de granos por panículas, porcentaje de fertilidad de las panículas, peso de 1000 granos y macollamiento por planta definieron la mayor productividad de los genotipos de mayor rendimiento (L-9, L-39, POBL1-34, POBL 3-13), siendo estos los genotipos que presentaron mayor resistencia a enfermedades. Además estos genotipo s presentan; buen porte de planta (tipo semienano), tolerancia al acame y ciclo intermedio. El testigo INTA DORADO y las líneas L-9, POBL 1-34 presentaron una calidad industrial de 94/06, 92/08 y 92/08, con respecto a la relación de grano entero/quebrado.
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应用作者所建立的高精度非定常激波装配法,数值模拟了高超声速条件下,钝锥绕流快声波来流扰动非定常流场,研究了钝锥超声速边界层对来流扰动感受性特征,研究表明,在各种来流扰动的条件下,钝锥边界层感受到的主要是声波扰动;钝锥边界层内扰动模态,在头部附近是第一模态,向下游依次转换为第二模态、第三模态;另外随钝度减小,边界层内扰动模态的振幅增大,但有一临界值,超过临界后反而减小,并且由于曲率间断的影响,模态振幅随钝度的变化不再是单调变化的.
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EXECUTIVE SUMMARY INTRODUCTION OVERVIEW OF INTERNATIONAL EBM HISTORY References CANADA Overview Activities to date Integrated Management implementation in Canada Objectives, indicators and reference points Assessment approaches Research directions for the future Management directions for the future References JAPAN Overview Conservation and sustainable use of marine living resources Harvest control by TAC system Stock Recovery Plan and effort regulation system Stock enhancement by hatchery-produced juvenile release Conservation and sustainable develop-ment on coastal waters The implementation of ecosystem-based management PEOPLE’S REPUBLIC OF CHINA Overview Current actions Output control Input control Summer fishing ban Enhance ecosystem health REPUBLIC OF KOREA Initiatives and actions of ecosystem-based management in Korea Current ecosystem-based management initiatives in Korea Precautionary TAC-based fishery management Closed fishing season/areas Fish size- and sex-controls Fishing gear design restrictions Marine protected areas (MPA) RUSSIA Existing and anticipated ecosystem-based management initiatives Issues related to the implementation of ecosystem-based management UNITED STATES OF AMERICA Definitions and approaches to ecosystem-based fishery management in the United States Present U.S. legislative mandates relating to ecosystem-based fishery management Target species Bycatch species Threatened or endangered species Habitats Food webs Ecosystems Integration of legislative mandates into an ecosystem approach Scientific issues in implementing ecosystem-based approaches References DISCUSSION AND RECOMMENDATIONS APPENDICES Appendix 10.1 Study group membership and participants Appendix 10.2 Terminology definitions Appendix 10.3 Present state of implementing ecosystem-based fishery management in Alaska: Alaska groundfish fisheries Appendix 10.4 Present state of implementing ecosystem-based fishery management off the West Coast of the United States: Pacific Coast groundfish fisheries Appendix 10.5 Descriptions of multi-species and ecosystem models developed or under development in the U.S. North Pacific region that might be used to predict effects of fishing on ecosystems Appendix 10.6 A potential standard reporting format (developed by Australia, and currently being used by the U.S.A in their contribution to this report) (83 page document)
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The aim of the present study was to investigate the functional role of syllables in sign language and how the different phonological combinations influence sign production. Moreover, the influence of age of acquisition was evaluated. Deaf signers (native and non-native) of Catalan Signed Language (LSC) were asked in a picture-sign interference task to sign picture names while ignoring distractor-signs with which they shared two phonological parameters (out of three of the main sign parameters: Location, Movement, and Handshape). The results revealed a different impact of the three phonological combinations. While no effect was observed for the phonological combination Handshape-Location, the combination Handshape-Movement slowed down signing latencies, but only in the non-native group. A facilitatory effect was observed for both groups when pictures and distractors shared Location-Movement. Importantly, linguistic models have considered this phonological combination to be a privileged unit in the composition of signs, as syllables are in spoken languages. Thus, our results support the functional role of syllable units during phonological articulation in sign language production.
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A comprehensive study on the thermal stability and spectroscopic properties of Er3+/Yb3+-codoped Al(PO3)(3)-based fluorophosphate glasses is reported of the 1.5μ m fibre amplifiers in this paper. From optical absorption spectra, the Judd-Ofelt parameters of Er3+ in the glasses and several important optical properties, such as the radiative transition probability, the branching ratio and the spontaneous emission probability, have been calculated by using Judd-Ofelt theory. The fluorophosphate glass exhibits broadband near-infrared emission at 1.53μ m with a full width at half-maximum over 63nm, and a large calculated stimulated-emission cross-section of 6.85 x 10(-21)cm(2).
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晚第三纪是云南地区环境演变过程中的关键地质历史时段,本论文以晚第三纪晚中新世(吕合)、晚上新世(羊邑和龙陵)地层中的孢粉为研究对象,结合同层位大化石植物证据,参照现代植被,恢复了云南三个化石出产地区的古植被垂直分布景观,并定性地描述了古气候;同时运用共存分析方法(The Co-existence Approach)定量化地重建了三个地区的古气候参数值;初步推测了沉积地可能的古海拔。 吕合晚中新世孢粉植物群含52个孢粉类型,隶属38科,其中25个类型鉴定到属级。植物群中被子植物占73.1%,裸子植物占11.5%,蕨类植物占15.4%。 吕合孢粉植物群的组成反映该地区在沉积时期植被具有垂直分带特征,沉积地附近分布有常绿阔叶林,包括壳斗科的青冈属、栲属、石栎属和漆树科等植物,以及多种亚热带和温带阔叶成分;林中混生少量针叶树(如松属和杉科等);林内蕨类植物较少;距沉积地较远的海拔较高的地区分布由铁杉属、冷杉属、雪松属和云杉属组成的针阔混交林或针叶林。 吕合地区晚中新世的气候参数:年均温:13.3-20.9℃,最热月均温:22.5-27.5℃,最冷月均温:2.5-12.6℃,年较差:12.1-24.8℃,年降雨量:803.6-1254.7mm,最大月降雨量:179.4-281.9mm,最小月降雨量:10.2-18.5mm。 羊邑晚上新世孢粉植物群含52个孢粉类型,隶属32科,其中36个类型鉴定到属级。植物群中被子植物占61.5%,裸子植物占9.6%,蕨类植物占25.0%,藻类植物占3.9%。 羊邑孢粉植物群的组成反映在沉积时期该地区的植被具有明显垂直分带特征。湿性常绿阔叶林分布在沉积地附近,以壳斗科的石栎属、青冈属和栲属为主,混生漆树科、桃金娘科、蓼科、大戟科和金缕梅科的枫香属等植物,林内蕨类植物丰富;针阔叶混交林分布在距沉积地较远海拔较高的山地,主要包括松属,铁杉属,罗汉松属和一些阔叶植物类群;云杉林、冷杉林和铁杉林分布在更高海拔的地区。 根据植物群的组成推测羊邑沉积地的古海拔不高于2000m。 羊邑地区晚上新世的气候参数:年均温:13.3-20.9℃,最热月均温:22.5-27.5℃,最冷月均温:1.9-12.6℃,年较差:12.3-25.8℃,年降雨量:797.5-1254.7mm,最大月降雨量:172.4-249.6mm,最小月降雨量:7.2-12.7mm。 龙陵晚上新世孢粉植物群含86个孢粉类型,隶属61科,其中45个类型鉴定到属级。植物群中被子植物占69.0%,裸子植物占4.6%,蕨类植物占24.1%,藻类植物占2.3%。 龙陵孢粉植物群反映当时沉积地区的植被具有明显垂直分带特征。沉积地附近分布有湿润常绿阔叶林,以壳斗科的青冈属、栲属和石栎属为主,混生杜鹃花科、藤黄科、漆树科和无患子科等植物,林内蕨类植物丰富;在距沉积地较远的高海拔的山地上分布有针阔混交林和针叶林,以松属、云杉属、冷杉属和铁杉属植物为主。 龙陵地区晚上新世的气候参数:年均温 18.6-22.1℃,最热月均温:22.8-27.5℃,最冷月均温:9.7-15.1℃,年较差:12.3-18.1℃,年降雨量:815.8-1254.7mm,最大月降雨量:172.4-249.6mm,最小月降雨量:9.8-11.3mm。 综合吕合、羊邑和龙陵孢粉植物群新研究资料和云南地区已有的第三纪孢粉学资料,云南地区晚第三纪时期孢粉植物群组成相对稳定,均已经反映常绿阔叶林、针阔混交林或针叶林垂直分布的植被景观,具有湿润的山地亚热带气候特点。与我国北方晚第三纪孢粉植物群相比,在对全球气候变化的响应上,云南地区晚第三纪孢粉植物群的变化不如北方显著;与我国南方其它地区晚第三纪孢粉植物群相比,虽然在对全球气候变化的响应均表现出不明显,但云南地区在植物区系组成上更为丰富。
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铃蟾属Bombina分布地跨欧亚二洲。近数十年来,国外学者对这类原始无尾类的分类和进化进行过不少研究,但亚洲产种类的种间亲缘关系仍不清楚,有些种在分类上尚存在疑问。本文以形态为基础,辅以核型资料,试图对中国铃蟾属的分类和进化问题进行探讨。研究结果发现:中国南部产3种(亚种)之间的亲缘关系较近,是一个祖先的后裔。其中强婚刺铃蟾B.fortinuptialis和微蹼铃蟾B.microdeladigitora之间形态差异为不明显,故建议强婚刺铃蟾作为微蹼铃蟾的一个亚种。东方铃蟾B.orientalis另一支系,其形态和核型与欧洲产两种相似, 文中还进一步讨论了铃蟾属的亚属划分是正确的。最后综合有关资料,探讨了铃蟾属的种间亲缘关系和该属的分类地位,并结合地史资料进行了铃蟾属物种分化的初步探讨。
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Because of its fascinating electronic properties, graphene is expected to produce breakthroughs in many areas of nanoelectronics. For spintronics, its key advantage is the expected long spin lifetime, combined with its large electron velocity. In this article, we review recent theoretical and experimental results showing that graphene could be the long-awaited platform for spintronics. A critical parameter for both characterization and devices is the resistance of the contact between the electrodes and the graphene, which must be large enough to prevent quenching of the induced spin polarization but small enough to allow for the detection of this polarization. Spin diffusion lengths in the 100-μm range, much longer than those in conventional metals and semiconductors, have been observed. This could be a unique advantage for several concepts of spintronic devices, particularly for the implementation of complex architectures or logic circuits in which information is coded by pure spin currents. © Copyright 2012 Materials Research Society.