酷想大晒台

哎呀呀,这个世界乱套了!大人变成了小孩,小孩变成了大人。现在,终于轮到各位小酷想家来当家做主了,快来看看他们都有什么出色的表现吧!看到爸妈变成了小孩,我立马学着他们的样子,下达了第一道命令:写作业去!我想他们一定会哭的,因为老师留的作业实在是太多了。新浪YOYO     

一年又一年

上了年纪的人都有相似的感觉,就是年纪越大,时间好像过得越快。小时候,过了元旦盼春节,过了春节盼五一、六一,过了六一盼国庆,过了国庆再盼元旦。时间总是那么漫长,盼望的假期似乎总是姗姗来迟。而如今,似乎一眨眼,一年就过去了。我给这个现象总结了一个理论,叫做相对     

百岁寿星 科学巨擘

贝时璋先生与20世纪同行,经历了百年世事沧桑,目睹了世纪科技巨变,体会了人生的无尽乐趣;同时,他也对中国生物物理学的发展做出了杰出贡献,展示了人生的巨大价值.     

分子生物学对进化论的影响

自从1953年DNA双螺旋结构发现以后,紧接着对生物大分子的各种新发现层出不穷,生物学可谓就进入了分子生物学的时代,它使人们对生物学的认识提高到了一个新的水平,也开拓了新的领域.当然,分子生物学也使进化论的研究转入了一个更精细的水平,解决了进化论中一些争论的问题,同时也提出了一些新的研究思想和观点.     

2005年中国科学院生命科学和医学学部新当选院士简介

方精云生态学家。北京大学教授。1959年出生于安徽怀宁。1982年毕业于安徽农学院林学系,1989年获日本大阪市立大学生物学博士学位。现任中国生态学会副理事长及国内外多个学术刊物的副主编或编委。建立了我国陆地植被和土壤碳储量的研究方法,系统研究了我国陆地生态系统的碳储量及其变化,较早地开展了碳循环主要过程的野外观测,构建了中国第一个国家尺度的陆地碳循环模式,为我国陆地碳循环的研究奠定了基础;系统研究了我国大尺度的植被动态及时空变化,揭示了我国植被生产力的变化趋势、空间分异及其对气候变化响应的规律;系统开展了我国植被分布与气候关系的定量研究,提出了基于植被气候关系的我国植被带划分的原则和依据,首次采用统一的调查方法,较系统地研究了我国山地植物多样性的分布规律。     

中国生物材料专利保护及其现状分析

本文叙述了我国生物材料专利制度的变迁,耐我国生物材料的专利保护范围进行了论述,对生物材料的保藏问题进行了说明;对我国生物材料保护制度进了论述,并对我国生物材料领域的专利现状进行了分析,就如何加强我国生物材料的专利保护提出几点建议。     

浅谈天津市行道树的应用现状与选用分析

行道树是城市园林绿化的骨干树种,美化了城市景观,促进了城市生态环境的改善。对天津市现有行道树的选择与应用进行了分析,找出了天津市行道树栽植和管理方面存在的主要问题,提出了改变天津市行道树种应用现状的对策。     

合理施肥对银杏园土壤肥力和酶活性的影响

首次研究合理施肥对银杏园土壤肥力和酶活性的影响,结果表明合理施肥,改善了土壤理化性状,显著地提高了土壤肥力和土壤酶的活性;从而培育了银杏发达的根群,促进了树体的生长。增加了银杏鲜根重和百叶鲜重,减少了银杏黄化株率,提高了银杏挂果株率及种核的产量和品质。     

促进微生物实验技术创新水平的改革初探

为了加强对本科生综合素质和能力的培养 ,激发学生的学习兴趣 ,我们对微生物实验课的教学内容进行了一系列改革 ,优化了实验项目 ,节约实验成本 ,并且引入科研成果转化实验 ,同时改进了实验方法和手段 ,实验结果更为准确。这些措施蕴含了较高的理论水平 ,增加了教学信息量 ,明显提高了教学效果 ,为培养高素质人才奠定了基础。     

2015年中国微生物遗传学研究领域若干重要进展

中国微生物遗传学研究在2015年取得了重要进展。本文回顾了2015年度中国本土科研团队在微生物遗传学领域取得的若干重要科研进展,扼要介绍了若干重点论文,展示了中国科学家在本领域的学术贡献。在基础微生物遗传学领域,明确了调控基因表达的一系列重要生物大分子的组成、结构和功能,解析了微生物免疫系统识别外源核酸片段的分子基础,阐明了多个微生物来源重要活性物质的生物合成途径及新颖的酶学反应过程,发现了微生物基因表达调控的新机理,在微生物发育、进化与群体行为生物学方面也取得一定进展。在工业微生物遗传学方面,阐明了微生物制造及其分子基础。在病原微生物遗传学方面,研究了多个致病菌的遗传调控,明晰了致病菌-宿主相互作用的遗传机制,在基因组水平解析了微生物耐药、新发病原和环境微生物的遗传机理,为致病菌防控新措施的研发提供了基础。在微生物多样性与环境微生物遗传学方面,展示了利用微生物遗传多样性的特点通过催化获得特定手性的化合物具有较好应用前景,肠道微生物组学研究方兴未艾。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.