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1.
毛面衣属主要分布于热带。迄今在中国毛面衣属仅采集到2个种,即东亚毛面衣和少果毛面衣。后者为首次报导。本文对该属及其2个种的分类特征、分布等方面进行了概述。  相似文献   

2.
杜仲提取物对鱼类病原菌作用的研究   总被引:2,自引:0,他引:2  
采用二次水浸提法提取杜仲有效成分进行杯碟法抑菌试验.结果表明,杜仲提取物对嗜水气单胞菌、鳗弧菌、温和气单胞菌具有较好的抑菌效果,而对大肠杆菌的抑菌效果不明显.通过SDS-聚丙烯酰胺凝胶电泳分析病原菌在杜仲提取物作用下蛋白的差异表达,结果发现,药物抑菌效果越明显的菌种,其蛋白表达的差异性就越大,且受抑制的蛋白和诱导表达的特异蛋白的分布比较广;而抑菌效果较差的菌种,其蛋白表达差异性较小.  相似文献   

3.
通过野外露头测量、沉积特征分析、沉积相恢复、孢粉组合和地球化学数据对比,对抚顺煤田始新统沉积演化过程及其对煤和油页岩发育的控制作用进行研究。结果表明:抚顺煤田始新统从古城子组扇三角洲和沼泽环境开始,经历了计军屯组浅湖和半深-深湖环境,最终演化为西露天组旋回性沉积;古城子组煤层主要在气候温暖潮湿、河流输入持续增加的淡水沼泽环境中沉积;计军屯组油页岩主要在气候向寒冷干燥条件转化、河流输入减少、水体变咸的半深-深湖环境中沉积;贫矿油页岩作为煤到富矿油页岩的过渡层位显示了高等植物和水生有机质双重输入的特征;煤和油页岩沉积条件的不同造成有机质母质来源的差异和水介质条件的改变,引起与油页岩共生煤系的"富氢化"和生油潜力的增大。  相似文献   

4.
M Godinot  M Mahboubi 《Nature》1992,357(6376):324-326
The record of early fossil Simiiformes (Anthropoidea) from the Late Eocene and Early Oligocene of Africa and the Arabian Peninsula has increased dramatically in recent years. We report here the discovery of a new, diminutive and much older (Early or Middle Eocene) simian from an Algerian locality, Glib Zegdou. This species is smaller than any other living or fossil African simiiform. Derived similarities shared with Aegyptopithecus suggest that the new genus is more closely related to propliopithecines than to oligopithecines, implying that these two subfamilies differentiated during the Early Eocene. The new discovery confirms predictions about the great antiquity of Simiiformes and emphasizes a long and endemic African history for higher primates.  相似文献   

5.
采用单因素和正交试验方法对超声波辅助提取杜仲籽蛋白工艺进行了优化.先选取料液比、超声时间、超声温度、浸提pH值等条件对杜仲籽蛋白的提取工艺进行单因素实验,采用L9(34)正交试验确定本工艺最佳条件.实验结果表明,在超声波辅助提取杜仲籽蛋白最佳工艺条件(料液比为1∶25,超声时间为30 min,超声温度为50 ℃,浸提pH值为10.0)下,杜仲籽蛋白提取率为77.03%.  相似文献   

6.
为了从现有的白粉菌属分类特征体系出发,客观地研究和评价中国白粉菌属(Erysiphe)的种级分类,根据28个形态学编码性状对66个物种样本进行了类平均法系统聚类分析(UPGMA).结果表明:寄主是白粉菌属种级分类的重要指标之一;白粉菌属下暂不宜分组;不支持将鼬瓣花白粉菌(Erysiphe galeopsidis)分出本属并以之作为模式种建立新白粉菌属(Neoerysiphe)、以及将金丝桃白粉菌(E. hyperici)和车轴草白粉菌(E. trifolii)转入叉丝壳属(Microsphaera)的分类观点.  相似文献   

7.
A new genus with a new species of fossil elaterid, Paraprotagrypnus superbus gen. et sp. nov., from the Middle Jurassic Jiulongshan Formation in Daohugou Village (N41°18.979′, E119°14.318′), Shantou Township, Ningcheng County, Inner Mongolia, China is described and illustrated. The genus Paraprotagrypnus belongs to the family of Elateridae, subfamily of Protagrypninae and tribe of Protagrypnini. Some primitive characters of the new genus and new species shed light on the ages between the Jiulongshan Formation in Inner Mongolia and the Yixian Formation in the western Liaoning Province of China. The habitat of the new species is briefly discussed.  相似文献   

8.
对机械振动焊接试板与常规埋弧自动焊接试板进行了残余应力测试、金相观察及疲劳试验 ,研究了机械振动焊接对焊件疲劳寿命的影响 .结果表明 ,机械振动焊接可降低焊接残余应力、细化焊缝和热影响区的金相组织 ,提高焊件疲劳寿命 .在本试验条件下 ,纵向残余应力降低 43% ,横向残余应力降低 2 5% ;振动焊接试样热影响区的晶粒度为 5级 ,而常规埋弧自动焊接试样热影响区的晶粒度为 3级 ;振动焊接试样的疲劳寿命提高 35% .并应用金属疲劳理论分析了振动焊接提高焊件疲劳寿命的内在本质  相似文献   

9.
应用石蜡切片法和实验室综合提胶法,研究了杜仲叶的结构发育,探讨了杜仲叶结构发育与杜仲胶积累的变化规律,旨在确定杜仲叶的最适采收季节,为生产实践提供参考。结果表明,杜仲叶内杜仲胶随着季节的变化基本呈跳跃式变化;叶片发育早期,随着栅栏薄壁组织、海绵组织等叶肉细胞的分化发育,叶片中的含胶细胞也在不断地形成、积累。七月份叶片组织结构发育成熟时,含胶细胞仍继续增加和生长,叶片含胶率总体上呈增加的趋势。由于杜仲树叶内杜仲胶为一年逐步积累的结果,11月份将近黄落的叶子含胶量较高,为1.19%。综合分析叶片生物量和杜仲胶的含量,11月份杜仲叶子黄落时收集较合适。  相似文献   

10.
Ni X  Wang Y  Hu Y  Li C 《Nature》2004,427(6969):65-68
The debut of undoubted euprimates (primates of modern aspect) was in the early Eocene, about 55 Myr ago. Since their first appearance, the earliest euprimates can be distinguished as Cantius, Donrussellia and Teilhardina. Nonetheless, the earliest euprimates are primarily known from isolated teeth or fragmentary jaws. Here we describe a partially preserved euprimate skull with nearly complete upper and lower dentition, which represents a new species of Teilhardina and constitutes the first discovery of the genus in Asia. The new species is from the upper section of Lingcha Formation, Hunan Province, China, with an estimated age of 54.97 Myr ago. Morphology and phylogeny analyses reveal that the new species is the most primitive species of Teilhardina, positioned near the root of euprimate radiation. This discovery of the earliest euprimate skull known to date casts new light on the debate concerning the adaptive origin of euprimates, and suggests that the last common ancestor of euprimates was probably a small, diurnal, visually oriented predator.  相似文献   

11.
The Dajin conglomerate, which is one of the most important sedimentary successions of the Xigaze forearc basin in Tibet, China, consists of deep-shallow marine tuffaceous turbidites and clastic rocks bearing Nummulites, Assilina, Alveolina and Lockhartia. These fossils are very similar to the foraminiferan in the Jialazi and Maila conglomerates, and those in Gangba and Dingri areas. They developed in the Eocene. By analyzing the spatial variation of Eocene sedimentary environments of Tibet Plateau and the foraminiferan in the Dajin conglomerate, we found that Eocene sedimentation should take place on both sides of the Yarlung Tsangpo suture, and the late Eocene tectonic uplifting should make the forearc basin expose out of the sea level and begin to receive nonmarine deposits.  相似文献   

12.
圆盘青钱柳Cyclocarya scutellata Guo为郭双兴(1979)建立于海南岛长昌盆地长昌组的新种,但根据果柄、果的大小以及所谓的"翅脉"等特征,作者认为郭双兴(1979)建立的"圆盘青钱柳Cyclocarya scutellata Guo"并不成立,这类标本应是莲的果实的不同保存状态,不能归入Cyclocarya.因此,郭双兴(1979)提出的关于青钱柳属可能起源于海南岛始新世的推论也就缺乏化石依据.  相似文献   

13.
Asian origin for Polystichum (Dryopteridaceae) based on rbcL sequences   总被引:8,自引:2,他引:6  
Chloroplast rbcL sequences of 60 species of Polystichum sensu lato (s.l.), including 23 new sequences from southwest China, were used to assess the phylogenetic relationships within the genus. On the basis of estimated evolution rate of rbcL gene and the genetic distance data that passed relative-rate tests, we further estimated the divergence times between some clades of the genus. The phylogenetic relationships were inferred using the neighbor-joining and maximum-parsimony methods, both methods producing trees with completely congruent topology. These trees reveal that all species of Polystichum s.l. in this study (including Cyrtomium and Cyrtomidictyum) form a monophyletic group. The basal split in Polystichum s.l. separates a clade with all Asian members from a clade containing other species from all over the world. The phylogenetic and divergence time estimation results lead us to suggest that Polystichum s.l. originated in Asia in the late Late Cretacous (≈76 Ma) and migrated into other places in the world in early Eocene(≈46 Ma).  相似文献   

14.
 圆盘青钱柳Cyclocarya scutellata Guo为郭双兴(1979)建立于海南岛长昌盆地长昌组的新种,但根据果柄、果的大小以及所谓的“翅脉”等特征,作者认为郭双兴(1979)建立的“圆盘青钱柳Cyclocarya scutellata Guo”并不成立,这类标本应是莲的果实的不同保存状态,不能归入Cyclocarya。因此,郭双兴(1979)提出的关于青钱柳属可能起源于海南岛始新世的推论也就缺乏化石依据。  相似文献   

15.
Gebo DL  Dagosto M  Beard KC  Qi T  Wang J 《Nature》2000,404(6775):276-278
The middle Eocene primate family Eosimiidae, which is known from sites in central and eastern China and Myanmar, is central to efforts to reconstruct the origin and early evolution of anthropoid or 'higher' primates (monkeys, apes and humans). Previous knowledge of eosimiid anatomy has been restricted to the dentition and an isolated petrosal bone, and this limited anatomical information has led to conflicting interpretations of early anthropoid phylogeny. Here we describe foot bones of Eosimias from the same middle Eocene sites in China that yield abundant dental remains of this primate. Tarsals of Eosimias show derived anatomical traits that are otherwise restricted to living and fossil anthropoids. These new fossils substantiate the anthropoid status of Eosimias and clarify the phylogenetic position of anthropoids with respect to other major primate clades. Early anthropoids possessed a mosaic of primitive and derived traits in their postcranial skeletons, reflecting their derivation from haplorhine ancestors that retained many prosimian-like features.  相似文献   

16.
:(1)当代蝗虫类的种属比率 ,单型属、寡型属和多型属的百分比同鸟类非常接近 ,即单型属高居首位 ,寡型属次之 ,多型属沦于末位。 (2)蝗虫类分布在中国的有217属 ,其中单型属、寡型属和多型属的百分比同全世界的情况完全相反 ,多型属最多 ,寡型属居中 ,单型属最少。(3)中国的蝗虫类单型属同近缘属的主要区别特征标准较为一致 ,属的地位相对稳定  相似文献   

17.
山茶属新资料   总被引:1,自引:0,他引:1  
报道山茶属1新种,云南半宿萼茶CameliaskogianaYe,对连山红山茶与超长柄茶的花及秃山茶的果,分别作补充或更正描述.所引证的标本分别保存于美国国家植物标本馆及中山大学植物标本馆  相似文献   

18.
抚顺矿区煤层气资源条件综合分析   总被引:1,自引:0,他引:1  
通过对抚顺矿区煤层气地质特征、储层特征及煤层气资源量的系统而深入分析,认为该区煤层气资源条件良好,主煤层巨厚而集中、煤阶相对较高、煤岩类型有利于煤层气的生成、主煤层顶板的巨厚油页岩有利于煤层气的保存、且含气量相对较高、渗透性好、1200m以浅的煤层气资源量还有41.65×108m3。同时对矿区井下瓦斯抽放利用和煤层气利用的下游市场进行了评述,指出抚顺矿区是使我国煤层气产业走出困境,寻求突破的最佳试验战场。  相似文献   

19.
抚顺矿业集团对油页岩进行炼油所采用的工艺为抚顺式干馏工艺。本文简要介绍了该工艺的发展历史,重点介绍了抚顺矿业集团研发出的三种抚顺式干馏工艺的流程、产品及主要技术特点。研究结果表明,抚顺矿业集团对油页岩资源的开发利用已经形成了油、热、电、化工等多联产产业体系。  相似文献   

20.
对济南九如山进行植物资源调查过程中,首次发现白花碎米荠Cardamine leucantha (Tausch) O. E. Schulz在山东省的分布,该种隶属于十字花科Brassicaceae碎米荠属Cardamine。基于野外调查和标本研究,描述了该种的形态特征,讨论了分布情况及新分布的意义,同时,提供了山东省碎米荠属植物分类检索表。  相似文献   

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