Dinosaurs on the north slope, alaska: high latitude, latest cretaceous environments

Abundant skeletal remains demonstrate that lambeosaurine hadrosaurid, tyrannosaurid, and troodontid dinosaurs lived on the Alaskan North Slope during late Campanian-early Maestrichtian time (about 66 to 76 million years ago) in a deltaic environment dominated by herbaceous vegetation. The high ground terrestrial plant community was a mild- to cold-temperate forest composed of coniferous and broad leaf trees. The high paleolatitude (about 70 degrees to 85 degrees North) implies extreme seasonal variation in solar insolation, temperature, and herbivore food supply. Great distances of migration to contemporaneous evergreen floras and the presence of both juvenile and adult hadrosaurs suggest that they remained at high latitudes year-round. This challenges the hypothesis that short-term periods of darkness and temperature decrease resulting from a bolide impact caused dinosaurian extinction.     

松属的起源、演化及扩散

在松属的系统演化、化石历史和现代分布研究的基础上,讨论了松属的起源、演化和扩散问题.松属的现代分布中心在北美洲,但原始类群主要集中在中国西南-越南一带,康滇古陆晚三叠纪地层发现了最早的松属孢粉化石,因而这一地区是松属的起源地,起源时间为三叠纪.起源后向西通过地中海区到达欧洲、北美,向东北穿过白令陆桥到达北美,向南到达印度尼西亚,向北到达西伯利亚和北极地区.     

Warmth of the subpolar north atlantic ocean during northern hemisphere ice-sheet growth

Two 10,000-year periods of Northern Hemisphere continental ice-sheet growth stand out prominently within the last full interglacial-to-glacial cycle. During the first half of each rapid ice-growth phase, the subpolar North Atlantic from 40 degrees N to 60 degrees N maintained warm sea-surface temperatures comparable to those of today's ocean. The juxtaposition at latitudes 50 degrees N to 60 degrees N of an "interglacial" ocean along-side a "glacial" land mass, particularly along eastern North America, is regarded as an optimal configuration for delivering moisture to the growing ice sheets.     

Central North Atlantic Plate Motions over the Last 40 Million Years

The relative motion vector for the North American and African plates has been determined from detailed charting of the trend of the Atlantis fracture zone for over 1000 kilometers in the central North Atlantic near 30 degrees N and from identification of marine magnetic anomalies and deep-sea drilling results. The vector (pole) is located at 52.5 degrees N, 34 degrees W and has a magnitude (opening rate) of 5.7 x 10(-7) degree per year. Major changes in either the pole location or the opening rate are not evident for the last 40 million years.     

我国林蛙属物种的分类学研究综述

林蛙(Wood frog)是一类具有背侧褶、非繁殖期生活在山林中的棕色蛙类,是两栖类的重要组成部分,主要分布于亚欧大陆的暖温带地区和北美洲西部。从形态分类学、细胞分类学、分子系统学3个方面对我国林蛙属物种的分类学研究进展进行了综述,以期为林蛙属的进一步研究提供资料。     

中国叩甲科昆虫属的分布类型与特征分析

通过统计中国科学院动物研究所标本馆、中山大学生物防治国家重点实验室昆虫标本室、华中农业大学昆虫标本室和深圳职业技术学院生物应用工程系昆虫标本室叩甲科昆虫定名标本和相关资料,分析了中国叩甲科昆虫属的区系分布特点。结果表明:除异角叩甲亚科Pityobiinae在古北界没有分布外,其余11个亚科在东洋界和古北界均有分布;东洋界的特有属很多,达到64属,占到总数的一半(50%)。从各区的分布情况看,分布于华南区的属最多,达到100属,占总数的78.1%;华北区和青藏区分布的属最少,分别只有21和14个属,分别占总数的16.4%和10.9%。中国叩甲科昆虫在中国动物地理区划中共有37个分布型,其中华南区的种类最多,达到37属,占总数的28.9%;其次为华南、西南、华中3区共有种类,为13属,占总数的10.2%;再其次为华南、华中2区共有种类,为8属,占总数的6.3%。     

Thermophilic ostracod: aquatic metazoan with the highest known temperature tolerance

The upper lethal temperature for an ostracod of the genus Potamocypris collected from a thermal stream ranged from 49 degrees C for incubation of more than 5 hours to 55.75 degrees C for 1-minute incubations. Field collections were held at 35 degrees C for less than 24 hours before experimental incubations. Calculated temperatues for 50 percent mortality for 60, 40, 20, 10, 5, and 1 minute of exposure were 50.44 degrees , 50.96 degrees , 51.43 degrees , 52.03 degrees , 52.77 degrees , and 55.12 degrees C, respectively.     

Pleistocene glaciation in the blue ridge province, southern appalachian mountains, north Carolina

Glacial polish, grooves, and striations discovered at an elevation of 1370 meters in the headwaters of Boone Fork on Grandfather Mountain, North Carolina, indicate the former, existence of alpine glaciation at a latitude of 36 degrees 07'N. The Boone Fork glacier was located 890 kilometers south of the previously recognized southern limit of alpine glaciation in the Appalachian Mountains, and 350 kilometers southeast of the nearest point on the Laurentide ice sheet. This find has significant implications for studies of Pleistocene geomorphology, paleobiology, and paleoclimatology in the eastern United States.     

Polychlorobiphenyls in North Atlantic ocean water

Concentrations of polychlorobiphenyls (PCB's) have been measured at the surface and at various depths in the water of the North Atlantic Ocean between 26 degrees N and 63 degrees N. The concentrations average about 20 parts per trillion and amount to an estimated 2 x 10(4) metric tons of PCB's in the upper 200 meters of water. The average concentrations of PCB's in the surface water of the Sargasso Sea are lower than those in the northern North Atlantic.     

新疆委陵菜属植物区系成分分析

本文对新疆境内已记载的３４种委陵莱属（Ｐｏｔｅｎｉｔｉｌｌａ　Ｌ．）植物进行了区系成分分析，其中包括：（１）世界分布型；（２）北温带分布型，（３）环北极高山分布型；（４）欧亚北极高山分布型；（５）旧世界温带分布型；（６）温带亚洲分布型；（７）高加索－伊朗－天山分布型；（８）东地中海分布型；（９）西伯利亚－天山分布型；（１０）亚洲中部分布型；（１１）天山－伊朗分布型；（１２）沿喜马拉雅（包括天山）分布型；（１３）阿尔泰－天山分布型；（１４）天山山地分布型；（１５）中国西北部特有种。统计结果表明：旧世界温带分布型的种类最多，有６种，占总数的１７．６％。温带亚洲分布型和沿喜马拉雅分布型次之，均为４种，各占总数的１１．８％。关键词     

Forebrain temperature activates behavioral thermoregulatory response in arctic sculpins

Arctic sculpins of the genus Myoxocephalus adapted to water at 5 degrees C escaped from warm water at 20 degrees , 16 degrees , and 12 degrees C when their deep-body temperatures increased from an initial 5 degrees C to about 8 degrees C. Heating parts of the forebrain with water at 25 degrees C circulating through a pair of thermodes astraddle rostral parts of the forebrain shortened the time spent in the warm water and lessened the incease in deep-body temperature before exit from the warm water. Cooling the forebrain to about -1 degrees C caused a large increase in the body temperature and sometimes suppressed the escape from the warm water.     

Foraminifera and chlorophyll maximum: vertical distribution, seasonal succession, and paleoceanographic significance

Many planktonic foraminiferal species deposit their shells at the chlorophyll maximum zone, and it is the temperature range here that is relevant to oceanographic models which use ratios of oxygen-18 to oxygen-16 in fossil foraminifera and foraminiferal fossil assemblages to ascertain past climates. During periods of stratification of the upper water column, the temperature at the chlorophyll maximum may differ from the sea surface temperature by 10 degrees C in the western North Atlantic.     

小兴安岭菊科植物区系地理与多样性研究

[目的]为小兴安岭菊科植物资源的保护和合理开发利用提供理论依据。[方法]采用野外调查和标本鉴定的方法,对小兴安岭菊科植物物种多样性、区系地理成分和经济用途多样性等进行了研究。[结果]该区共有菊科植物126种,隶属48属,且优势属明显,少种属和单种属占总属数的比例分别为37.50%和56.25%。从属层次上表现出典型的温带性质,以北温带成分为主,且没有我国特有属。[结论]小兴安岭菊科植物组成丰富,区系地理成分多样,经济用途多样。     

Decadal sea surface temperature variability in the subtropical South Pacific from 1726 to 1997 A.D

We present a 271-year record of Sr/Ca variability in a coral from Rarotonga in the South Pacific gyre. Calibration with monthly sea surface temperature (SST) from satellite and ship measurements made in a grid measuring 1 degrees by 1 degrees over the period from 1981 to 1997 indicates that this Sr/Ca record is an excellent proxy for SST. Comparison with SST from ship measurements made since 1950 in a grid measuring 5 degrees by 5 degrees also shows that the Sr/Ca data accurately record decadal changes in SST. The entire Sr/Ca record back to 1726 shows a distinct pattern of decadal variability, with repeated decadal and interdecadal SST regime shifts greater than 0. 75 degrees C. Comparison with decadal climate variability in the North Pacific, as represented by the Pacific Decadal Oscillation index (1900-1997), indicates that several of the largest decadal-scale SST variations at Rarotonga are coherent with SST regime shifts in the North Pacific. This hemispheric symmetry suggests that tropical forcing may be an important factor in at least some of the decadal variability observed in the Pacific Ocean.     

Interannual variability of temperature at a depth of 125 meters in the north atlantic ocean

Analyses of historical ocean temperature data at a depth of 125 meters in the North Atlantic Ocean indicate that from 1950 to 1990 the subtropical and subarctic gyres exhibited linear trends that were opposite in phase. In addition, multivariate analyses of yearly mean temperature anomaly fields between 20 degrees N and 70 degrees N in the North Atlantic show a characteristic space-time temperature oscillation from 1947 to 1990. A quasidecadal oscillation, first identified at Ocean Weather Station C, is part of a basin-wide feature. Gyre and basin-scale variations such as these provide the observational basis for climate diagnostic and modeling studies.     

小兴安岭东折棱河流域植物区系特征研究

[目的]明确小兴安岭蔷薇科植物区系特征。[方法]研究小兴安岭东折棱河流域植物区系组成、优势科属组成以及属的地理成分。[结果]该区共有高等植物103科284属486种,裸子植物种类少,但在当地森林植被中是优势类型。东折棱河流域科的优势现象比较明显,种类集中趋向于少数科类,寡种科和区域性单种科较丰富;属的优势现象不明显,多集中于寡种属和区域性单种属。苔藓植物属的地理成分复杂,以北半球温带成分占优势,并有不少的世界分布成分;蕨类植物属的地理成分类型较少,以寒温带成分为主,并伴有世界成分和热带亚热带成分;种子植物属的地理成分类型较多,以北温带成分(48.9%)为主,各温带成分比例(81.3%)更大,说明该区系具有相对的独立性。植物生活型中草本植物占绝对优势,物种比例高达77.2%,为苔藓植物和蕨类植物。[结论]该研究结果为开发利用小兴安岭蔷薇科植物资源提供了参考。     

Pleistocene avifaunas and the overkill hypothesis

At the end of the North American Pleistocene, birds and mammals suffered comparable degrees of generic extinction. Both the magnitude and pattern of avian extinction are incompatible with the hypothesis that humans played a major role in causing the demise of numerous North American mammalian genera at this time.     

On Pleistocene Surface Temperatures of the North Atlantic and Arctic Oceans

Two additional interpretations are given for the important data of D. B. Ericson on the correlation of coiling directions of Globigerina pachyderma in late Pleistocene North Atlantic sediments with ocean surface temperatures. One interpretation relates the distribution of this species to the distribution and circulation of ocean water masses. On the basis of our ice-age theory, our second interpretation uses the data and correlations of Ericson to establish temperature limits of a thermal node, a line on which glacial and interglacial temperatures were equal, for the North Atlantic Ocean. This line crosses the strait between Greenland and Scandinavia. Further, Ericson's interpretation of the 7.2 degrees C isotherm implies that the glacial-stage surface waters of the Arctic Ocean were between 0 degrees and 3.5 degrees C.     

大麦属的亲缘关系与分类

<正> 植物的亲缘关系和分类、在理论上阐明种的形成,发展和种间相互关系,在应用上提供丰富的种质资源以及近缘和远缘杂交的有效途径,为创造新物种开辟广阔前景。直到本世纪五十年代,大麦属的分类基本上是按形态学来划分的。因此存在同种异名,同名异种,种间和种内亚种、变种间界限不明的混乱现象。由于近代细胞遗传学的发展,核型、染色体同源性和倍性、遗传基因型和杂交亲和性的研究,使大麦属的分类发展到一个新的阶段。     

Subsurface circulation in the somali current

Direct velocity measurements were made at intermediate depths along the East African coast from March to July 1979. Strong time-dependent flows with multiple reversals in direction were found in the upper 1000 meters between 3 degrees N and 4 degrees S. At 700 meters, there may be a connection between the southwestward coastal current and an equatorial jet observed at 49 degrees E, the latter turning south near the coast. North of 3 degrees N little spatial organization of the flow can be recognized.