南亚和东南亚龙胆属(龙胆科)的新名称、新组合及分类注释     

何廷农  刘尚武 《中国科学院研究生院学报》2000,38(1):10-12

本文提出了龙胆属两个种的新名称(Gentiana membranulifera T．N．Ho,G．nudicaulisKurz var. assa- mensis T．N．Ho)和5个变种的新组合[(Gentiana lateriflora Hemsl．var. uncifolia(H．J．Lam)T．N．Ho, G．sumatrana Ridl．var．humifusa(S．Moore)T．N．Ho,G. quadrifaria Bl．var．wightii(Kusnez．)T．N．Ho, G．loerzingii Ridl. var．timida(Kerr)T．N．Ho,G．membranulifera T．N．Ho var．recurvata (Kusnez．)T．N．Ho)〕。  相似文献   

翼萼蔓属系统位置的研究     

陈世龙  何廷农  洪德元 《中国科学院研究生院学报》1998,36(1):58-68

 对翼萼蔓属进行了外部形态、花部解剖学、大小孢子发生和雌雄配子体发育、花粉形态和染色体 的研究,并以此为据,讨论了该属的分类等级和系统位置。翼萼蔓属的花具花冠腺体。花萼筒具16条 维管束,花冠筒具12条维管束,二者的维管束是独立发生的。每心皮具1条背维管束和2条腹维管束。 雄蕊先熟。花药四室;药壁发育为双子叶型;绒毡层异型起源,细胞具双核,属腺质型绒毡层;一层中层 细胞;药壁表皮层宿存,细胞膨大,细胞壁纤维状加厚;药室内壁部分纤维状加厚。小孢子母细胞减数分 裂的胞质分裂为同时型;成熟花粉为3-细胞型。子房为2心皮,1室,超侧膜胎座;胚珠25～40列,倒生 胚珠,腹维管束靠近腹缝线。薄珠心,单珠被。大孢子母细胞减数分裂形成的4个大孢子呈直线式排 列,其中合点端的大孢子具功能。胚囊发育为蓼型。极核在受精前融合为次生核,反足细胞3个,具反 足吸器。胚乳发育为核型。花粉球形,极轴长约32.8μm,赤道轴长约34.2μm,外壁纹饰为网状纹 饰。体细胞染色体数为2n=26,染色体基数为x＝13,核型公式为2n＝26＝18m＋4sm+2st＋2t,属 2A型。比较翼萼蔓属、蔓龙胆属和扁蕾属的外部形态、花部解剖学、胚胎学、花粉形态和染色体特征,表 明翼萼蔓属和扁蕾属可能具较近的亲缘关系,起源于一个较早的共同祖先。在分类等级上,把翼萼蔓属作为一独立属处理较为合适。  相似文献   

高职“建筑行业英语”教材编写必要性的研究   总被引：1，自引：0，他引：1  

何飞云  David HO 《金华职业技术学院学报》2010,10(3):25-27

在＂工学结合＂的指导思想下,建筑行业的高职英语教学需要考虑提高学生的就业竞争力。教材好坏直接影响教学过程的质量和效果,是实现培养目标的重要保证。基于前人对高职英语教材的研究,目前高职院校采用的《新编实用英语》有一定的局限性;同时,对建筑类毕业生的调查发现,大多数学生认为在工作中或自我职业的发展中需要了解和使用建筑行业英语。目前对高职建筑行业英语教材编写的研究很缺乏,高职院校对建筑行业英语教材编写进行研究很有必要。  相似文献   

Altitude and endurance training   总被引：4，自引：0，他引：4  

Rusko HK  Tikkanen HO  Peltonen JE 《Journal of sports sciences》2004,22(10):928-44; discussion 945

The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (< 2000-2200 m) and/or too short an altitude training period (<3-4 weeks); (2) the training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.  相似文献