黄土高原西部会宁地区66万年以来冰期—黄土旋回的孢粉记录

根据野外剖面观测及古地磁资料,将会宁黄土地层与兰州、洛川黄土地层进行对比。在孢粉分析的基础上,把该区约66万年以来的植被与气候演变历史划分为13个阶段,并将其与深海沉积氧同位素阶段及冰期旋回进行了对比。约66万年以来,该地植被变化于温性针阔叶混交林与荒漠草原之间,气候变化于温暖半湿润-寒冷干旱之间。     

BIOCHEMICAL CHANGES DURING DEVELOPMENT OF EGGS AND YOLK-SAC LARVAE OF HERRING AND PLAICE

Changes in quantities of water, sodium, potassium, lipid and protein were compared in developing eggs and yolk-sac larvae of herring dupes harengus L., a species with demersal eggs, and plaice Pleuroncctcs platessa L., a species with pelagic eggs. The principal difference between the two species was the occurrence in herring, but not in plaice of considerable increases in water content and in one or both of the above ions at three distinct stages: at fertilization,during the middle stage of egg development, and in the days immediately after hatching. Newly hatched larvae of the two species differed greatly in water content because of the difference in mass and water content of the yolk, not in the water content of the rest of the body. In herring, there were increases in sodium and potassium which coincided broadly with the increase in water content. These differences are related to the gradual acquisition of buoyancy by herring during this period, comparable with the buoyancy conferred on plaice eggs a     

海平面升降变化对贵州紫云礁体生长的控制

以贵州紫晚二叠世碳酸盐台地边缘礁为例,运用高频层序地层学原理和方法,精细地划分了紫云礁层序的各级单元,并对其内部沉积构成进行了详细研究,探讨海平面和变化对礁体生长的控制,研究结果表明,晚二叠世紫云礁 合体为发育在台地边缘坡折带的一个三级层序,由１３个准层序组成,并可识别出低位、海侵、高位３个体系域,低位期的下切谷 边缘坡折带碳酸盐台地的暴露、海侵期和高位期礁的３种生长方式的增生及每种生长方式的特定     

Climate change of the last millennium inferred from borehole temperatures: regional patterns of climatic changes in the Czech Republic — Part III

Accurate temperature–depth profiles may help to assess the temperature variations associated with the climate changes in the past. Ninety-eight ground surface temperature histories inverted from the temperature–depth borehole logs drilled on the territory of the Czech Republic [Bodri, L., ermák, V., 1995. Climate changes of the last millennium inferred from borehole temperatures: results from the Czech Republic — Part I. Global Planet. Change 11, pp. 111–125; Bodri, L., ermák, V., 1997. Climate changes of the last two millennia inferred from borehole temperatures: results from the Czech Republic — Part II. Global Planet. Change 14, pp. 163–173.] are used to reconstruct the regional patterns of the respective climate change. The climate was mapped for the following periods: 1100–1300 A.D. (Little Climatic Optimum), 1400–1500 A.D., 1600–1700 A.D. (main phase of the Little Ice Age), and for the most recent climate trend after year 1960. Comparison of the obtained maps with the meteorological observations and proxy climatic reconstructions confirmed good applicability of the “geothermal” paleoclimatic reconstructions for the regional studies.     

新疆棉花"矮密早"栽培技术的气候条件

简要论述了新疆棉花“矮密早”栽培技术形成的气候条件和依据。     

Holocene regional and local vegetation history and lake-level changes in the Torneträsk area, northern Sweden

A combination of pollen and macrofossil analyses from six lakes at altitudes between 370 and 999 m above sea level (a.s.l.) in the Torneträsk area reflect the Holocene vegetation history. The main field study area has been the Abisko valley at altitudes around 400 m a.s.l. The largest lake, Vuolep Njakajaure has annually laminated (varved) sediments. The chronology and sedimentation rates in the pollen-influx calculations are based on varve yrs in this lake and on radiocarbon dated terrestrial plant macrofossils in the other lakes. A strong increase of mountain birch (Betula pubescens ssp. tortuosa) during the early Holocene with a tree-line c. 300 m above the present, indicates that the summer temperature was c. 1.5 °C higher than today, assuming that the land uplift has been 100 m since then. Scattered stands of pine (Pinus sylvestris) may have been growing in the area immediately after the deglaciation but a forest consisting of pine and mountain birch expanded first at low elevations and reached the eastern parts of the Torneträsk area at c. 8300 cal BP and the western parts at c. 7600 cal BP. The highest pine-birch forest limit was not reached until 6300 cal BP (110 m above present pine limit). Warm and dry conditions during the pine forest maximum led to lowering of the water level documented in Lake Badsjön in the Abisko valley about 1-1.5 m lower than today. Pine and mountain birch were growing at the maximum altitude until c. 4500 cal BP. Assuming that land uplift has been in the range of 20-40 m since the mid-Holocene, this implies that the temperature was then c. 1.5-2 °C higher than today. Rising lake-levels and lowering limits of pine and mountain birch since c. 4500 cal BP indicate a more humid and cool climate during the late Holocene.     

中国江南先秦时期人类活动与环境变化

从江南先秦时期不同阶段内遗址内涵和位置的变化着手,分析江南人类活动与环境变迁的关系,探索江南先秦文化遗址中文化层年代不连续的原因,找提出江南先秦文化中心变迁的路径。江南先民是从适应自然走向改造自然道路的,由于认识和改造自然的能力有限,江南土著文化随自然条件发生兴衰,而这种兴衰又成为土著文化相互渗透和交融的动力。     

古尔班通古特沙漠南部沙垄水分动态--兼论积雪融化和冻土变化对沙丘水分分异作用

2004年3月至2005年7月对古尔班通古特沙漠南部典型半固定沙垄土壤水分进行了系统监测,结合气象资料,特别是对冬季积雪和冻土资料的分析,认为该沙漠沙丘土壤水分时空变化规律在很大程度上受积雪融化和季节性冻土的影响.由于冬季稳定存在20~30 cm的积雪于春季融化,使得春季沙丘土壤含水率成为全年最高的季节,从而为早春植物的萌发生长创造了有利的条件.冬季1 m多深的冻土于早春时节由表及里开始消融,沙丘表面融化的雪水在坡面重力作用下,沿难以透水的冻土层上界自坡上向坡下发生迁移,在春夏季形成了垄间最高、坡部次之和垄顶最少的土壤水分空间格局.该研究具有生态学意义,可为古尔班通古特沙漠特殊环境条件下植被恢复与重建提供依据.     

新疆气象台站迁移及其对气候变化分析的影响

由于诸多原因,如城乡规划建设、外部环境遭受破坏和工作环境需要改善等,新疆现有105个国家基准气候站、国家基本气象站和一般气象站从1950年起到2004年,搬迁达73个站150次,占全区地面气象站总数的70%。气象台站搬迁在某种程度上会影响观测数据的连续性和一致性,特别对于气候变化分析工作,更要求数据的历史延续性。本文分析了新疆台站迁移状况以及台站迁移后对数据连续性的影响,为使用这些数据的研究人员分析研究新疆气候变化提供了很好的参考信息。     

温度、湿度对地磁Z基线值的影响及分析

仪器墩体受潮湿影响所产生的局部形变而引起的ZB磁变仪倾斜,是引起成都台CB3ZB变化幅度大,形成N字型年变化及其它类似形态变化的主要原因。实践证明,水泥墩湿引起的形变大,防潮效果差。而质地单纯均匀的石头墩受潮湿后引起的形变小,防潮效果好。