共查询到20条相似文献，搜索用时 157 毫秒
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国家自然科学基金委员会（以下简称自然科学基金会）自1986年成立
以来机械学科资助了2200多项基础研究项目，推动了我国机械工程学科的发展；为机\\r
械工程提供了一大批新理论、新技术和新方法，提升了我国制造业及其装备的技术水平；同
时培养和造就了一大批高素质和高学术水平的专家、学者和教授。本文回顾了自然科学基金\\r
会成立以来机械学科的发展历程，总结了基金管理工作中的基本经验，指出了目前研究中存\\r
在的不足与差距。 相似文献
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本文在分析国际权威刊物《农业经济学》近两个年度的热点论文和近\\r
两届国际农业经济年会论文的基础上，结合国内农业经济管理专家问卷调查的统计分析结果\\r
，提出农业经济管理研究的重点资助方向与领域。 相似文献
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中国黄土：最近250万年地球气候与环境变化的记录者 总被引：1，自引：0，他引：1
经过几代中国第四纪环境研究者的努力，已经认识到，中国黄土堆积
是过去250万年以来连续的风成沉积物，黄土堆积序列中的粒度、磁化率、碳同位素、生物\\r
化石等可以作为古气候与古环境变化的良好替代性指标，中国黄土堆积中包含着最近250万\\r
年以来东亚季风气候与黄土高原植被变化过程等信息。中国黄土已经成为认识第四纪地球气\\r
候与环境变化的三个重要信息载体之一。对黄土记录的深入研究，将对理解地球系统变化的
规律与机制、为黄土高原以及中国西北地区的生态环境建设提供科学依据。 相似文献
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我国免疫性皮肤病基础研究现状与展望 总被引：1，自引：0，他引：1
本文总结近5年（1999—2003年）国家自然科学基金资助免疫性皮肤\\r
病基础研究的情况，并主要介绍了结缔组织病、自身免疫性大疱病、银屑病基础研究成果和
进展。 相似文献
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本文对我国药学科学基础研究近年来的
发展状况、研究水平和存在问题进行了分析并对今后的发展战略、目标和优先资助领域等提\\r
出了建议。 相似文献
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天然免疫系统非克隆识别机制的进展 总被引：6，自引：0，他引：6
本文综述了高等动物存在两大相互依存、相互作用的完整的抗感染防
御\\r
系统,即天然免疫的非克隆识别机制和以克隆选择为基础的获得性免疫。天然免疫的非克隆
识别机制诱导抗原提呈细胞表达共刺激因子,触发获得性免疫反应,并通过释放细胞因子引
导获得性免疫系统发生特异的免疫效应反应。在天然免疫反应中,通过胚胎细胞编码的受体\\r
识别病原体几种特有的保守分子,诱导天然免疫细胞表达抗菌肽、共刺激因子和效应细胞因\\r
子。认识天然免疫识别的分子机制,在疫苗设计和发展免疫治疗新举措上,意义重大。 相似文献
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包士英 《中国科学院研究生院学报》1984,22(1):57-63
The present paper is an outcome of taxonomic study of Chinese passifloraceous plants. It contains 2 genera, 23 species, 2 varieties and 7 cultivarieties, of which one species is described as new and two are first recorded from China. The Chinese passifloraceous plants are mainly distributed in Yunnan (2 gen. 16 sp.), Guangdong (2 gen. 9sp.) and Guangxi (2 gen. 8 sp.). 相似文献
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郝日明 《中国科学院研究生院学报》1997,35(6):500-510
中国种子植物特有属是局限分布于中国行政区域范围内的植物成分，就其分布特点看，集中分布于中国南部亚热带广阔区域。由于中国地域广袤，虽然大多数特有属分布在东亚自然地域范围内，但南部特有属的分布范围已进入古热带植物区的马来亚森林植物亚区的北部，而西部的特有属的分布范围已进入青藏高原地区。局限于不同地域分布的特有属，各自的起源发生、所经历的地质历史过程存在一定差别。本文以自然地理区划作为研究中国种子植物特有属分布区类型的依据，将中国特有属分布区类型划分为中国东部和中部特有分布变型、中国南部特有分布变型、中国西部特有分布变型和中国北部特有分布变型4类。其中中国南部特有分布变型所含特有属为热带区系成分，其它3个特有分布变型所含特有属为温带区系成分。这样能较客观地反映中国特有属的自然地理特征，有利于研究局部地区植物区系的地质历史演变过程。 相似文献
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The “Quan Fang Bei Zu”, a first dictionary for Chinese plants, which contains 27
volumes in its first collection and 31 volumes in its second collection, was completed by
Chen Jing-yi in 1253, the First Year of Bao You of Li Zong in Song Dynasty. The
first part of this encyclopaedia of plants is devoted to flowers. The second part is of
more varied nature, dealing with fruit trees, plants in general, herbs, trees, agriculture
and sericulture, vegetables, and medicinal herbs. These two collections cover 267 kinds
of plants, each of which is described under two categories separately: The first category,
“Si Shi Zu” in Chinese, meaning “facts of the plants” concerned, which again divided
into 3 entries, i.e. the history, miscellaneous information and sundry bits of the plants.
The second category, “Fu Yong Zu” in Chinese, meaning poetry, which divided into
10 meters, wherein the plants are described and eulogized in poetrical expressions.
Later on, the “Quan Fang Bei Zu” was used as a blueprint for some famous books
in China, for example, the “Qun Fang Pu” and the “Guang Qun Fang Pu” all written
and compiled after its model. It is known today that in China there are only two
extant hand writting copies of it, one in Beijing Library, the other in the Library of
Yunnan University. Both of them are listed as the best national books. Outside China,
it is known that a third copy of is in the Congress Library in U.S.A. As for the ori-
ginal wood-carving copy printed during the period of the Song Dynasty, it is known so
far that one copy is kept in the Library of Culture Ministry of Japan. The Beijing
Agriculture Publishing House has made a decision to photograph this carved copy in
the Culture Ministry of Japan as one of the “Precious Series of China Agriculture
Science”. The book plays a very important role in the study of chinese botany, agri-culture science, medicine, history and literature. 相似文献
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本文根据作者等10多年来对广西杉木林生产力测定数据和与之相匹配的年平均气温、温暖指数、降水量、温度指数和实际蒸散量等气象数据，用最小二乘法建立了杉木林的气候生产力模型，给出了全区杉木林气候生产力分布，并与迈阿密和桑斯威特数学模型的计算结果做了比较分析。结果 杉木林、气候生产力、模型、广西 相似文献
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BackgroundWheat is one of the most important crops cultivated all over the world. New high-yielding cultivars that are more resistant to fungal diseases have been permanently developed. The present study aimed at the possibility of accelerating the process of breeding new cultivars, resistant to eyespot, by using doubled haploids (DH) system supported by marker-assisted selection.ResultsTwo highly resistant breeding lines (KBP 0916 and KBH 4942/05) carrying Pch1 gene were crossed with the elite wheat genotypes. Hybrid plants of early generations were analyzed using endopeptidase EpD1 and two SSR markers linked to the Pch1 locus. Selected homozygous and heterozygous genotypes for the Pch1-linked EpD1b allele were used to produce haploid plants. Molecular analyses were performed on haploids to identify plants possessing Pch1 gene. Chromosome doubling was performed only on haploid plants with Pch1 gene. Finally, 65 DH lines carrying eyespot resistance gene Pch1 and 30 lines without this gene were chosen for the eyespot resistance phenotyping in a field experiment.ConclusionsResults of the experiment confirmed higher resistance to eyespot of the genotypes with Pch1 in comparison to those without this gene. This indicates the efficiency of selection at the haploid level.How to cite: Wiśniewska H, Majka M, Kwiatek M, et al. Production of wheat doubled haploids resistant to eyespot supported by marker-assisted selection. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.003 相似文献
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台湾位于欧亚大陆东南缘的海洋中，地处热带的北部和亚热带的南部，约为21°45′~15°56′N，119°18′~124°34′E，是中国最大的岛屿。它是受季风气候强烈影响的地区之一，热量丰富，雨量充沛，干湿季明显。具有一个非常丰富的岛屿和山区植物区系。就其种子植物而言，约有186科，1201属，3656 种，包括热带属742属，温带属346属。根据台湾植物区系中各大科、主要植物群落优势种和中国特有种的地理分布以及热带属在整个植物区系中的主导地位，台湾地区的植物区系主体具有明显的亚热带性质。中国台湾本地特有种十分丰富，其比例远高于中国特有种的比例。这似乎表明台湾植物区系是一个古老区系在多次地质事件侵袭后又起活化的历史演变的结果。新老成分并存、共同发展是台湾植物区系的重要特点。通过台湾全部属和非特有种在周边地区地理分布的分析，中国台湾植物区系与中国大陆的关系最为密切，是东亚植物区系的重要组成部分，因此在植物分区上应属于泛北极植物区的东亚植物区系。 相似文献
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本文介绍了近年来在昆虫分类学领域研究热点之一的DNA条形码技术,综述了我国基于COI基因进行的昆虫分类学研究,并对COI基因对我国昆虫分类学的未来应用进行了展望。 相似文献
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The Chinese medicine “Chuipencao” is studied. But, as a matter of fact, this
Chinese name represents two distinct forms, one with broad leaves and the other with
narrow leaves. As a result of a comprehensive study on gross morphology, pollen mor-
phology, histological structure, isozymes, GC analysis of chemical constituents of the
plants in question has shown that the narrow-leafed form is different from the broad-
leafed form and therefore is considered as a new species, Sedum angustifolium Z. B.Hu et X. L. Huang sp. nov. 相似文献
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《国家科学评论(英文版)》2014,(2)
Cytosine DNA methylation is an epigenetic modiication in eukaryotes that maintains genome integrity and regulates gene expression. he DNA methylation paterns in plants are more complex than those in animals,and plants and animals have common as well as distinct pathways in regulating DNA methylation. Recent studies involving genetic, molecular, biochemical and genomic approaches have greatly expanded our knowledge of DNA methylation in plants. he roles of many proteins as well as non-coding RNAs in DNA methylation have been uncovered. 相似文献