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 843 毫秒
1.
采用文献资料法、调查访问法、逻辑分析法和归纳法,论述了我国普通高等学校体育课程师资队伍建设的现状,探讨了存在的问题,提出了对策与建议.  相似文献   

2.
3.
4.
 The fern genus Diplaziopsis C. Chr. of Index Filicum has long been considered as a monotypic one, with the sole species, D. javanica (B1.) C. Chr. from tropical Asia.  In 1906, H. Christ described a second species, Allantodia cavaleriana Christ (=D. cavale- riana C. Chr.) from Kweichow, West China, but this was since not fully recognized by fern students in general, being often considered as a variety of the first species.  This is certainly a mistake, as is shown by ample herbarium specimens today.  In the recent work on the genus, the writer has found among the herbarium material two additional new species from China, thus bringing the genus up to four species in Asia, mainly from China, where, as it is, the genus has its center of development from the long past.      Phylogenetically, Diplaziopsis C. Chr. represents one of the offshoots from the great stock of diplazioid ferns, of which the genus Diplazium Sw. constitutes the main body of the group and from which our genus differs chiefly in its leaves of a thin texture with reticulated venation, but not so much in its type of indusium as it has generally been emphasized by most botanists in the past, for, as it is, the type of indusium in Di- plaziopsis also prevails in many species of Diplazium, for which C. B. Clarke (Trans. Linn. Soc. ser. 2, Bot. I:495, 1880) created, but really superfluously, a subgenus Pseudal- lantodia, about which the writer will dwell in another paper in the near future.  Suffice it to say here that the indusium in Diplaziopsis as revealed by the species treated here is, indeed, typical of diplazioid ferns, only often, as it happens, with  its  adaxial  edge pressed so tight under the expanding sorus that it is unable to open freely along its upper free edge and, as a result, its thin vaulted back bursts open from the pressure of the ex- panding sorus underneath.      As a result of the present study, following four species of the genus have been re- cognized.      Diplaziopsis javanica (B1.) C. Chr. Ind. Fil. (1905) 227.      Wide spread in tropical Asia, northwardly to Bakbo and the southern part of Yun- nan, China.      D. cavaleriana (Christ) C. Chr. Ind. Fil. Suppl. I (1913) 25.      Ranges from West China through northern part of Fukien of East China to Japan.      D. intermedia Ching, sp. nov.      Endemic in West China:  Mt. Omei, Szechuan, and Kweichow.      D. hainanensis Ching, sp. nov.      In conclusion, it may be pointed out that with the modern plant taxonomy pursued in a more efficient manner than in the past, and especially by the introduction of the cytotaxonomic methods, the so-called “monotypic genera”, as conceived by the orthodox systematists, will continue to prove, to a great extent, to be lack of  enough  scientific ground.  The fact that the “monotypic genus” of Diplaziopsis C. Chr. is now found to be a genus of four well-defined species is once again an instance to illustrate the pointat issue.  相似文献   

5.
6.
论体育新学科的形成   总被引:5,自引:0,他引:5  
本文讨论了体育新学科形成的主动力、基本模式以及耦合性、系统性、多重性、创造性和脆弱性等特征 ,旨在加速体育新学科的创建  相似文献   

7.
8.
战后美国科学技术的大发展美国领先世界的科学技术,是从二次世界大战后逐渐建立的。战后不久,为加强原子能的研究开发,1946年美国成立了原子能委员会,成为国内最大的科学实体。1950年筹建国家科学基金会,作为联邦政府专门资助基础研究的机构。1957年前苏...  相似文献   

9.
10.
11.
An investigation of the relationship between National Institutes of Health (NIH) funding and the quantity and nature of biomedical publications is reported for 120 U.S. medical school complexes. A correlation of 0.95 was found between the amount of NIH funds received and the number of biomedical publications from the medical schools. Medical school ranks based on bibliometric measures were found to correlate at the 0.80-0.90 level with ranks based on peer assessments of the schools. The characteristics of the medical school papers varied with the type of school. The average citation influence per paper increased with the publication size of the schools. This was true even when factors such as public versus private control, geographic region, average research level (from basic to clinical), and subject emphasis were controlled. The positive relationship between number of papers from a school and its citation influence holds within individual research levels and within subfields.  相似文献   

12.
 将异枝竹属Metasasa W.T. Lin作为酸竹属Acidosasa C.D.Chu et C.S.Chao ex Keng f.的异名处 理。异枝竹Metasasa carinata W.T. Lin和白环异枝竹 Metasasa albo-farinosa W.T.Lin作为新组合名Aci-dosasa nanunica(McCl.)C.S.Chao et G.Y.Yang,comb.nov.的异名。  相似文献   

13.
14.
15.
 According to Wang and Xie, their recently  published  genus  Trirostellum  is distinguished from its allied genera by a number of characteristics: (1) the stamens with their filaments coherent into a central column; (2) the female flowers possessing rudimentary stamens; (3) the ovary 3-celled, with one ovule in each cell; (4) the fruits dehiscent, 3-rostrated at the apex; (5) the fruits possessing persistent perianth; (6) the seeds tuberculate and winged.  However, upon a careful comparison of Trirostell- um yixingensis Z.P. Wang et Q. Z. Xie, the type species of Trirostellum with Gyno- stemma pentaphyllum (Thunb.) Mak., the type species of Gynostemma Bl.  and some other species of Gynostemma as well,we have found that the representatives of the above two genera are identical in most of the important diagnostic characteristics ex- cept that the fruits of the former genus are dehiscent with three long beaks at  the apex, while the fruits of the latter genus are indehiscent  with  very  short  beaks. Besides, results obtained from chromosome counting haove  shown that the somatic chromosome number of Trirostellum yixingensis is 2n=22, while that of Gynostemma pentaphyllum is 2n=28.Yet these morphological and chromosomal differences seem not sufficient for generic demarcation.  We, therefore, suggest that Trirostellum bereduced to a sectional or subgeneric rank of Gynostemma Bl.  相似文献   

16.
17.
浅析美国动漫产业的文化与现状   总被引:3,自引:0,他引:3  
现在劝漫产业是资金密集型、科技密集型、知识密集型和人才密集型的重要经济一文化产业,是21世纪开发潜力巨大的世界热门产业.英国是当今世界上最大最强的动漫产业国.本文对美国的动浸广业链的形成,动漫产业的游戏规则、动漫产业的职业精神、动漫的消费环境等方面进行了一定的剖析.  相似文献   

18.
19.
20.
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