Sea-floor spreading, carbonate dissolution level, and the nature of horizon a

Evidence from leg 2 of the Deep Sea Drilling Project suggests a constant spreading rate for the floor of the North Atlantic over the past 80 million years; a major lowering of the carbonate dissolution level during the early Pliocene; and an early to middle Eocene age for horizon A.     

傅氏凤尾蕨复合群孢子形态的扫描电镜观察

傅氏凤尾蕨复合群(Pteris fauriei complex)包括傅氏凤尾蕨Pteris fauriei、百越凤尾蕨P.fauriei var.chinensis、线裂凤尾蕨P.angustipinnula、硕大凤尾蕨P.majestica、隆林凤尾蕨P.splendida等,此复合群种间界限模糊,难以准确分类,为此笔者利用扫描电镜对此复合群植物的孢子形态进行观察,为理清成员间的亲缘关系提供佐证。观察发现,脊类纹饰是此复合群孢子的重要特征,根据脊类纹饰的有无和分布情况,该复合群可划分为4个类群。此外,孢子形态可作为此凤尾蕨复合群区分种的特征,但傅氏凤尾蕨和百越凤尾蕨的孢子形态较相近,难以区别。本研究还首次发现隆林凤尾蕨具有"连体孢子"。     

Quaternary pollen record from laguna de tagua tagua, chile

Pollen of southern beech and podocarp at Laguna de Tagua Tagua during the late Pleistocene indicates that cooler and more humid intervals were a feature of Ice Age climate at this subtropical latitude in Chile. The influence of the southern westerlies may have been greater at this time, and the effect of the Pacific anticyclone was apparently weakened. The climate today, wet in winter and dry in summer, supports broad sclerophyll vegetation that developed during the Holocene with the arrival of paleo-Indians and the extinction of mastodon and horse.     

Temperature and precipitation estimates through the last glacial cycle from clear lake, california, pollen data

Modern pollen surface samples from six lake and marsh sites in the northern California Coast Ranges establish a linear relation between elevation and the oakl(oak + pine) pollen ratio. Modern temperature and precipitation lapse rates were used to convert variations in the pollen ratio into temperature and precipitation changes. Pollen data from two cores from Clear Lake, Lake County, California, spanning the past 40,000 and 130,000 years were used to estimate temperature and precipitation changes through the last full glacial cycle. The maximum glacial cooling is estimated to be 7 degrees to 8 degrees C; the last full interglacial period was about 1.5 degrees C warmer than the Holocene, and a mid-Holocene interval was warmer than the present. The estimated precipitation changes are probably less reliable than the estimated temperature changes.     

由苏云金芽胞杆菌胞晶混合物直接提取原毒素的方法

采用室内实验技术,研究了直接从苏云金芽胞杆菌胞晶混合物提取原毒素的方法。胞晶混合物依次用0.5mol·L-1NaCl和无菌去离子水洗涤3次,洗涤后的沉淀物用0.05mol·L-1NaOH 0.1mmol·L-1PMSF溶液溶解10min,10000r·min-1离心15min去除不溶物。上清液以25%乙酸调至pH4.4,得原毒素蛋白沉淀,冷冻干燥。SDS-PAGE电泳扫描结果表明,原毒素分子量为130kDa,在提取过程中没有发生降解。该提取方法具有操作简便、成本低、效率高等优点。     

Eocene volcanism and the origin of horizon a

A series of closely time-equivalent deposits that correlate with seismic reflector horizon A exists along the coast of eastern North America. These sediments of Late-Early to Early-Middle Eocene age contain an authigenic mineral suite indicative of the alteration of volcanic glass. A volcanic origin for these siliceous deposits onshore is consistent with a volcanic origin for the cherts of horizon A offshore.     

Unique type of angiosperm pollen from the family annonaceae

The primitive antgiosperm family Annonaceae possesses a remarkable type of pollen that appears unique in its size (diameter up to 350 micrometers), lack of exine over nearly 50 percent of the grain surface at maturity, and proximalipolar aperture. This unique pollent is further distinguished by being in polyads which are compartmentalized individually within septate stamens.     

Fossil spores, pollen, and fishes from connecticut indicate early jurassic age for part of the newark group

Palynologically productive localities have been found in the United States throughout the Newark Group basins, most of which had previously been assumed to be barren. Rich palynoflorules dominated by coniferous pollen of Circulina-Classopollis type, and well-preserved fossil fishes, including possible new semionotids, have been found in the Hartford basin. Palynological data indicate that the Newark Group has considerable time-stratigraphic range: Upper Triassic for the Cumnock Formation (North Carolina), the Vinita Beds (Virginia), and the upper New Oxford Formation (Pennsylvania), Rhaeto-Liassic for the Brunswick Formation (New Jersey), Portland Formation (Connecticut and Massachusetts), and the Shuttle Meadow Formation (Connecticut).     

July temperatures in europe from pollen data, 6000 years before present

Mean July temperatures across Europe 6000 years before present were reconstructed from palynological data by the transfer function method. Reconstructed summer temperatures were warmer than those at present over most of Europe with the greatest heating, more than 2 degrees C, in the midcontinent and the far north. This pattern is explained by high summer insolation and a weak zonal insolation gradient 6000 years before present and the effective heating of the landmass relative to ocean and coastal areas. A strong land-sea pressure gradient may in turn have increased westerly air flow into southern Europe, which is consistent with cooler reconstructed summer temperatures in the Mediterranean region, and reduced the environmental lapse rate in the central European mountains.     

菊科绢蒿属10种植物的花粉形态研究

【目的】丰富和补充绢蒿属(Seriphidium(Bess.) Poljak.)植物系统分类学和种间演化关系的孢粉学资料。【方法】在光学显微镜(LM)和扫描电镜(SEM)下,对我国10种(其中2变种,1存疑种)绢蒿属植物的花粉进行了形态学研究,其中9种植物的光镜和扫描电镜资料为首次报道。【结果】10种绢蒿属植物花粉粒较小,呈长球形、球形或近球形,赤道面观为圆形或椭圆形,极面观为三裂片圆形;极轴(P)长(16.23~27.18)μm,平均为22.52μm,赤道轴(E)长(15.51~23.13)μm,平均为17.22μm,P/E平均值为1.31;具三孔沟,孔沟长达极区,不弯曲,沟的末端在极面上不连接形成合沟(存疑种除外);外壁2层,外层厚于或近等厚于内层;花粉外壁纹饰在光学显微镜下为细颗粒,在扫描电子显微镜下以刺状-颗粒状复合纹饰为主。【结论】绢蒿属和蒿属有着较近的亲缘关系。     

花粉和蜂粮中细菌的分离和鉴定

对中国茶(Camellia sinensis O.Ktze.)的手采花粉(floral pollen)、蜂花粉(corbicular pollen)和不同酿制时间的蜂粮(bee bread)样品中的细菌进行分离和鉴定.从样品中分离出207个菌落,鉴定出4个属的12种细菌,即詹氏乳杆菌(Lactobacillus jensenii)、果糖乳杆菌(Lactob.fructosus)、旧金山乳杆菌(Lactob.sanfrancisco)、绿色乳杆菌(Lactob.viridescens)、唾液乳杆菌(Lactob.salivarius)、微小乳杆菌(Lactob.minor)、干酪乳杆菌鼠李糖亚种(Lactob.casei subsp.rhamnosus)、植物乳杆菌(Lactob.plantarum)、无害利斯特氏茵(Listeria innocua)、格氏利斯特氏茵(List grayi)、枯草芽孢杆菌(Bacillus subtilis)和植物乳球菌(Lactococcusplantarum).     

Caribbean eocene volcanism and the extent of horizon a

Layer A and its correlative layer A" in the Caribbean have been interpreted as chert layers produced by Eocene volcanism. Exposures of Eocene volcanic rocks in Puerto Rico and the Dominican Republic may represent layer A interbedded with coarser volcanic debris and preserved near early Tertiary volcanic centers.     

Lithology and paleontology of the reflective layer horizon a

Cores recovered from horizon A are Late Cretaceous (Maestrichtian) in age and consist o alternating layers of calcareous turbidites and "red clay." The presence of red clay suggests that the water depth in this area during Cretaceous time was at least as great as at present-more than 5100 meters. A middle Cretaceous (Cenomanian) core consisting of interbedded sand and gravel and light-to-dark-gray lutite was taken in the same area from a layer stratigraphically below the horizon; the presence of hydrogen sulfide and iron sulfide may indicate anaerobic conditions that may be attributable to local ponding of sediment in Cenomanian time.     

刺五加ATP合酶β亚基基因的克隆与序列分析

[目的]克隆刺五加叶绿体的ATP合酶β亚基cDNA并对其进行生物信息学分析。[方法]根据已知物种叶绿体ATP合酶β亚基基因的序列,设计1对同源引物,通过RT-PCR扩增得到刺五加ATP合酶β亚基cDNA,并对其进行序列比对及结构预测分析。[结果]RT-PCR扩增获得了长1099bp的刺五加ATP合酶β亚基cDNA,该基因编码366个氨基酸。序列比对及结构预测分析表明,刺五加ATP合酶β亚基基因编码的氨基酸与水稻的同源性最高,达96.41%。其二级结构中含有171个α螺旋（alpha helix）,占46.72%;53个延伸链（extended strand）,占14.48%;27个β折叠（beta turn）,占7.38%;115个无规则蜷曲（random coil）,占31.42%。第262～271位氨基酸为ATP合酶β亚基的标志性位点。整个多肽链无明显的疏水区域,初步认定为亲水性蛋白。[结论]该试验克隆得到的ATP合酶β亚基基因为叶绿体ATP合酶β亚基基因,为研究刺五加能量代谢对植物次生代谢的影响及了解植物ATP合酶的结构与功能提供了必要的信息。     

刺五加ATP合酶β亚基基因的克隆与序列分析

[目的]克隆刺五加叶绿体的ATP合酶β亚基cDNA并对其进行生物信息学分析。[方法]根据已知物种叶绿体ATP合酶β亚基基因的序列,设计1对同源引物,通过RT-PCR扩增得到刺五加ATP合酶β亚基cDNA,并对其进行序列比对及结构预测分析。[结果]RT-PCR扩增获得了长1 099 bp的刺五加ATP合酶β亚基cDNA,该基因编码366个氨基酸。序列比对及结构预测分析表明,刺五加ATP合酶β亚基基因编码的氨基酸与水稻的同源性最高,达96.41%。其二级结构中含有171个α螺旋(alpha helix),占46.72%;53个延伸链(extended strand),占14.48%;27个β折叠(beta turn),占7.38%;115个无规则蜷曲(random coil),占31.42%。第262～271位氨基酸为ATP合酶β亚基的标志性位点。整个多肽链无明显的疏水区域,初步认定为亲水性蛋白。[结论]该试验克隆得到的ATP合酶β亚基基因为叶绿体ATP合酶β亚基基因,为研究刺五加能量代谢对植物次生代谢的影响及了解植物ATP合酶的结构与功能提供了必要的信息。     

早竹花粉形态与生物学特性

通过对早竹花粉形态与生物学特性的观测,研究早竹花而不实的原因。通过对早竹花料形态、花粉活力、花粉萌发率、柱头授粉能力和花粉管生长的观察测定,得出：①早竹花粉为近球形,具单一萌发孔,外壁纹饰为颗粒状;②早竹花粉萌发率低下,柱头自然授粉能力弱是导致早竹花而不实的主要原因之一;③早竹花粉管生长速度较快,最高可达３．４４μｍ．ｍｉｎ＾－１。从而为早竹人工授粉和实行杂交育种等研究提供参考依据。     

7个茶树品种的花粉形态与生活力研究

为研究不同茶树品种之间花粉的形态特征与生活力变化,以7个茶树品种为试材,进行花粉形态结构观察及其随培养时间增长萌发率的变化趋势研究。结果表明:(1)7个茶树品种花粉均呈左右对称,具有3个萌发沟,长度和宽度差异不显著,萌发沟长度、宽度以及延伸比例呈现多样性,赤道面观呈椭圆形和棱锥形,极面观呈圆形和近三角形;外壁呈现光滑瘤状和粗糙瘤状,且部分品种花粉表面有穿孔。(2)在24 h的培养时间内,7个茶树品种的花粉萌发率均呈"S"型曲线增长,且基本上在1、3和5 h呈现显著性差异增长,到7 h接近萌发峰值。其中,柿大茶黄种、龙井43、福鼎大白茶的花粉萌发率较高,而云抗10号的花粉萌发率均显著低于其他6个品种。对中国种舒茶早(Camellia sinensis var. sinensis ‘Shuchazao’)与阿萨姆种云抗10号(Camellia sinensis var. assamica ‘Yunkang 10’)的花粉在不同贮藏条件下的生活力进行进一步的比较,发现它们在4℃和–20℃温度下的生活力存在显著差异,在180d的贮藏时间内,舒茶早与云抗10号分别在–80℃与–20℃的贮藏温度下对其花粉活力的保存更适宜。