Reaction of plutonium dioxide with water: formation and properties of PuO(2+x)     

Haschke JM  Allen TH  Morales LA 《Science (New York, N.Y.)》2000,287(5451):285-287

Results show that PuO(2+x), a high-composition (x 相似文献   

不同处理方法对美国截叶胡枝子种子发芽的影响     

拉旦  欧阳克蕙  王堃 《草业与畜牧》2006,(4):14-16

美国截叶胡枝子的硬实率很高,发芽率只有17.3%.经过种子预处理,如采用不同温度下浸种、98%浓硫酸浸泡、机械破皮和机械破皮结合热水浸种等处理,结果表明,机械破皮后用60℃热水浸种处理的效果最好,发芽势和发芽率分别达到64.0%和74.3%;其次是机械破皮,平均发芽率达到50%;浓硫酸浸种可以显著提高种子发芽势,浓硫酸浸种5min效果最好,发芽率达到44.7%;热水浸种的处理效果不佳,最好的90℃热水浸种处理发芽率也仅有26.7%.  相似文献   

不同处理方法对美国截叶胡枝子种子发芽的影响   总被引：1，自引：0，他引：1  

拉旦  欧阳克蕙  王堃 《黑龙江畜牧兽医》2006,(8):57-58

截叶胡枝子(Lespedezacunecta)是原产于亚洲东部的一种多年生的豆科植物,在我国南方地区野生分布很广。它具有耐瘠、耐旱、耐酸、耐热、固土能力强、适应性广等特性,在国外也颇受重视。我国于1983年从美国引种,通过对其生物学和生态学特性、经济性状和栽培技术研究证明,引进的美国截叶胡枝子在人工栽培条件下,表现出良好的经济性状,是南方草地改良的希望种子。但是在生产中,由于其硬实的存在,使得种子的发芽率很低,往往造成出苗困难和草地建植缓慢,甚至出现严重缺苗断垄的现象,直接影响田间产量,限制了它的进一步推广应用。试验采用不同处…  相似文献   

不同处理方法对美国截叶胡枝子种子发芽的影响   总被引：2，自引：0，他引：2  

拉旦  欧阳克蕙  王堃 《四川草原》2006,(4):14-16

美国截叶胡枝子的硬实率很高,发芽率只有17.3%。经过种子预处理,如采用不同温度下浸种、98%浓硫酸浸泡、机械破皮和机械破皮结合热水浸种等处理,结果表明,机械破皮后用60℃热水浸种处理的效果最好,发芽势和发芽率分别达到64.0%和74.3%;其次是机械破皮,平均发芽率达到50%;浓硫酸浸种可以显著提高种子发芽势,浓硫酸浸种5min效果最好,发芽率达到44.7%;热水浸种的处理效果不佳,最好的90℃热水浸种处理发芽率也仅有26.7%。  相似文献   

Effects of Sodium Dodecyl Sulphate on Post-thaw Dog Semen Quality during in vitro Incubation at 39°C and 22°C     

AI Peña  F Barrio  LA Quintela  PG Herradón 《Reproduction in domestic animals》1998,33(6):393-398

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不同退化程度高寒草甸植物物种多样性与生态系统多功能性关系     

周宸宇  杨晓渊  邵新庆  张中华  马丽  秦瑞敏  佘延娣  苏洪烨  常涛  魏晶晶  胡雪  拉本  周华坤 《草地学报》2022,30(12):3410-3422

为探究高寒草甸不同退化程度生态系统多功能性的变化,本研究综合考虑了植物物种多样性和多种生态系统功能如生产力、养分循环和固存能力、土壤涵养水分能力等,运用降维因子分析的方法计算了生态系统多功能性,综合分析了植物物种多样性与生态系统功能和多功能性间的关系。结果表明：高寒草甸退化显著降低了Margalef指数、Shannon-weiner指数、Simpson指数和Pielou指数(P<0.05),各生态系统功能趋于恶化。高寒草甸退化导致生态系统多功能性的下降,综合统计量结果为轻度退化(21.9955)＞中度退化(8.7295)＞重度退化(—30.7245)。植物物种多样性与生态系统多功能性之间均存在正相关关系,其中Simpson指数与生态系统多功能性指数拟合的结果最好,说明高寒草甸生态系统多功能性受植物物种多样性的制约。本研究可为青藏高原草地退化及恢复的过程和机理研究提供理论依据。  相似文献   

Effects of two iron sources on iron and cadmium allocation in poplar (Populus alba) plants exposed to cadmium     

Fodor F  Gáspár L  Morales F  Gogorcena Y  Lucena JJ  Cseh E  Kröpfl K  Abadía J  Sárvári E 《Tree physiology》2005,25(9):1173-1180

Effects of 10 microM cadmium (supplied as Cd nitrate) on the utilization and allocation of iron (Fe) were investigated in poplar (Populus alba L.) plants grown in nutrient solution with Fe(III)-EDTA or Fe(III)-citrate as the Fe source. The effects of Cd were also compared with those of Fe deprivation. The accumulation of Fe in roots was 10-fold higher in plants grown with Fe-citrate than with Fe-EDTA. Cadmium decreased leaf chlorophyll concentrations and photosynthetic rates, and these decreases were more marked in plants grown with Fe-citrate than with Fe-EDTA. In both Fe treatments, addition of Cd caused large increases in root and shoot apoplasmic and non-apoplasmic Cd contents and increases in root Fe content; however, Cd decreased shoot Fe content, especially in plants grown with Fe-citrate. New leaves of plants grown with Fe-citrate had small cellular (non-apoplasmic) Fe pools, whereas these pools were large in new leaves of plants grown with Fe-EDTA. Non-apoplasmic Cd pools in new leaves were smaller in plants grown with Fe-citrate than with Fe-EDTA, indicating that inactivation of non-apoplasmic Cd pools is facilitated more by Fe-EDTA than by Fe-citrate. In the presence of Cd, Fe-EDTA was also superior to Fe-citrate in maintaining an adequate Fe supply to poplar shoots. Differences in plant responses to Fe-EDTA and Fe-citrate may reflect differences in long-distance transport of Fe rather than in acquisition of Fe by roots.  相似文献   

Radial variation in sap flow in five laurel forest tree species in Tenerife,Canary Islands   总被引：1，自引：0，他引：1  

Jiménez MS  Nadezhdina N  Cermák J  Morales D 《Tree physiology》2000,20(17):1149-1156

Variations in radial patterns of xylem water content and sap flow rate were measured in five laurel forest tree species (Laurus azorica (Seub.) Franco, Persea indica (L.) Spreng., Myrica faya Ait., Erica arborea L. and Ilex perado Ait. ssp. platyphylla (Webb & Berth.) Tutin) growing in an experimental plot at Agua García, Tenerife, Canary Islands. Measurements were performed around midday during warm and sunny days by the heat field deformation method. In all species, water content was almost constant (around 35% by volume) over the whole xylem cross-sectional area. There were no differences in wood color over the whole cross-sectional area of the stem in most species with the exception of E. arborea, whose wood became darker in the inner layers. Radial patterns of sap flow were highly variable and did not show clear relationships with tree diameter or species. Sap flow occurred over the whole xylem cross-sectional area in some species, whereas it was limited to the outer xylem layers in others. Sap flow rate was either similar along the xylem radius or exhibited a peak in the outer part of the xylem area. Low sap flow rates with little variation in radial pattern were typical for shaded suppressed trees, whereas dominant trees exhibited high sap flow rates with a peak in the radial pattern. Stem damage resulted in a significant decrease in sap flow rate in the outer xylem layers. The outer xylem is more important for whole tree water supply than the inner xylem because of its larger size. We conclude that measurement of radial flow pattern provides a reliable method of integrating sap flow from individual measuring points to the whole tree.  相似文献   

Potential of Gmelina arborea for solid wood products     

Morales  G.A. 《New Forests》2004,28(2-3):331-337

New Forests - This paper explains the process of producing healthy trees and sound wood for Gmelina arborea Roxb. (gmelina) in Costa Rica. Ston Forestal S. A. began planting gmelina in the early...  相似文献   

Ex Vivo Evaluation of Carpal Flexion After Partial Carpal Arthrodesis in Horses          下载免费PDF全文

Patty J. Tulloch DVM  James D. Johnston PhD  Spencer M. Barber DVM  Diplomate ACVS  Candace L. Gellert BSc  Hayley M. Lang DVM  Luca Panizzi DrMedVet  MVetSc  Diplomate ACVS‐LA 《Veterinary surgery : VS》2015,44(3):386-391

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