首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
利用扫描电镜对木犀属美丽木犀和布克木犀的花粉形态进行了观察与测量.结果显示:美丽木犀和布克木犀花粉在P/E值、外壁纹饰、萌发沟方面表现出一定的相似性,表现为花粉为近球形,外壁具有网状纹饰,三孔沟萌发;在花粉大小(P、E)、沟长(L)、沟深(D)、网眼大小等方面表现一定的差异性.通过对布克木犀、美丽木犀、山桂花花粉形态的比较,推测花粉大小、P/E值是判断其杂交起源的依据之一.  相似文献   

2.
几种常见观赏植物花粉的电镜观察   总被引:5,自引:0,他引:5  
用扫描电镜对金盏菊等观赏植物的花粉进行了形态观察,探讨了不同科属植物花粉之间的关系.结果显示,菊科(金盏菊和绿串珠)花粉为近球形或扁球形,表面为脑网状纹饰,具刺状突起;芸香科(佛手、柚和金桔)花粉为长球形,表面具清晰的网状纹饰或穴状纹饰;木兰科(含笑和广玉兰)花粉为两侧对称,表面为拟网状或脑网状纹饰;百合科(百合和吊兰)花粉为两侧对称,表面为网状或穴状纹饰;蔷薇科(野蔷薇和月季)花粉为长球形,表面为条纹状或皱波状纹饰.表明不同科属植物的花粉大小、形状、表面纹饰不同,可作为植物学分类的依据.  相似文献   

3.
杨德奎 《山东科学》2011,24(2):21-23
应用扫描电子显微镜对百合属(Lilium L.)植物3种1变种的花粉形态进行了观察研究。结果显示:花粉形态皆呈椭圆体,具单沟萌发器官。花粉粒在大小、外壁雕纹等性状上种间差异显著。  相似文献   

4.
我国特有植物七子花叶表面和花粉的扫描电镜观察   总被引:1,自引:0,他引:1  
应用扫描电镜技术对七子花叶表面和花粉的形态与微观结构进行了观察,并探讨了与其他一些忍冬科植物的异同.结果表明,七子花叶表皮粗糙,细胞不规则,排列紧密;上下表皮均被有单细胞非腺毛;气孔仅见于下表皮,为平列型,气孔下陷,副卫细胞相对于保卫细胞突出;表皮毛和气孔器在叶面上分布不规则;花粉近球形,具有3孔沟,沟稍长于孔,外壁纹饰小刺状.七子花与忍冬科其他一些植物的叶表面和花粉有许多共同特征,表现在叶表皮细胞形状,气孔的形状、类型和分布,花粉大小和外壁纹饰等方面.但七子花也有其独特的细微构造,尤其在表皮蜡质层的有无、非腺毛和气孔的形态结构与着生位置、花粉形状和孔沟数量等方面.  相似文献   

5.
木兰属(Magnolia L.)植物花粉亚微形态特征研究   总被引:3,自引:0,他引:3  
利用扫描电镜观察了木兰属(Magolia L.)4种植物花粉的亚微形态结构,对其特征进行了比较分析。结果表明:4种植物花粉外部形态均为肾脏形,具单萌发沟;外壁纹饰为覆盖层穿孔。但花粉大小和外壁纹饰的微细结构种间有明显的差异。因此,研究花粉的亚微形态结构特征,可为植物种类的鉴别和细致分类提供必要的形态学依据。  相似文献   

6.
首次报道了宁夏枸杞3个品种、一个变种的花粉在扫描电镜下的形态特征.结果表明:供试花粉均为小花粉类型,椭圆形,或近球形,三孔沟,等极,表面有夹带二岐分叉的条状纹饰作纵向排列.具不同条状纹饰和条纹表面的不规则细横纹是供试花粉的区别点.花粉的大小和形状,在供试各品种之间也有不同程度的差异  相似文献   

7.
蜡梅品种花粉粒扫描电镜特征的分类研究   总被引:2,自引:0,他引:2  
应用扫描电镜对蜡梅3个品种群共21个品种的花粉粒形态特征进行了观察和比较,对观测结果进行了主成分分析与聚类分析。结果表明:蜡梅花粉粒为中等大小,近扁球形至圆球形;蜡梅花粉外壁纹饰可分为蠕虫状和拟蠕虫状两个类型;蜡梅品种间花粉形态比较类似,但在纹饰细微特征、花粉粒大小、萌发沟长宽度等方面存在一定差异,可作为区分品种的辅助依据;花粉形态聚类分析结果与传统形态分类结果存在差异,花粉形态与内被片和中被片颜色并无直接关联。  相似文献   

8.
本文作者用光学显微镜和扫描电子显微镜对甘草属(Glycyrrhiza)八种植物花粉形态进行了详细观察和比较.本属花粉形态是单花粉类型;花粉粒为长球形或近园球形,极面观为三裂园形或钝园形;具3孔沟;花粉粒为中等大小(31·6~38·7μm);外壁分层明显;外壁纹饰为细网纹和网纹.用高速离心机对Gly-cyrrhiza uralensis和Glycyrrhiza glabra两种花粉进行破壁观察其外壁的内部结构.  相似文献   

9.
山东鼠尾草属花粉形态的研究及其在分类上的意义   总被引:5,自引:0,他引:5  
利用扫描电子显微镜首次对山东鼠尾草属(Salvia L.)3种植物的花粉形态进行了观察和研究。结果显示该属花粉为长球形和扁球形,具6沟,外壁具网状雕纹。探讨了花粉形态特征的分类学意义。表明本属花粉粒形状、大小和外壁雕纹可以作为种间分类的依据。  相似文献   

10.
中国野生牡丹花粉形态的研究   总被引:4,自引:0,他引:4  
通过扫描电镜观察了芍药科(Paeoniaceae)芍药属(Paeonia)牡丹组(Sect.Moutan DC.)9个野生种23个居群的花粉形态.该组花粉多为长球形,少数近球形和超长球形,具三拟孔沟,大小为22.7~46.4 μm×13.6~29.9 μm,外壁纹饰形态多样,可分为穴状、网状、粗网状、条纹-网状、皱波-网状、皱波状.分析结果表明:花粉形态与植物的外部形态特征有一定关系,同一种野生牡丹生长在不同的环境中,其花粉形态也不同.因此,花粉分析对牡丹组种的区分有一定的参考价值,但要合理揭示其系统发育意义,仍需进行更全面深入的研究.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号