全国季节冻土地区工程抗冻害学术讨论会将于今年8月在长春举行

由中国地理学会冰川冻土分会、中国水利学会岩土力学专业委员会、全国水工建筑物抗冻科研协作组、全国水工建筑物抗冻情报网等联合举办的全国季节冻土地区工程抗害学术讨论会将于今年8月     

垂线偏差-大地水准面与逆范宁-梅尼兹公式的应用——联合多种卫星测高数据求解全球海平面与海洋重力异常

卫星测高开辟了地球科学研究的新纪元。平均海面高(MSSH)和海洋重力异常是卫星测高在大地测量和地球物理应用领域的重要成果。平均海面高对于建立全球潮汐模型、海平面变化研究以及海洋测深等方面有重要意义。关于海洋重力异常的应用,Sandweel与Smith(1997)已进行了说明。根据卫星测高数据计算垂线偏差(DOV)是恢复重力异常的一个新途径。对利用改进的卫星测高数据进一步提高全球平均海面高和重力异     

FIELD INVESTIGATION INTO DEBRIS FLOW MECHANISM

1.INTRODUCTIONDebrisflowisadistincttypeofmassmovementcommonlytriggeredbyintenserainfallandmeltingsnowonsteephillslopes.Althoughgreateffortshavebeenmadeinthestudyofthemechanismofthemotion,considerableambiguitypersistsconcerningtheinitiationandmotionofdebrisflow.Debrisflowcanbeinitiatedinsteepslopebecauseofthehighgravitationalforceandcanalsobetriggeredbyheavyrainstormongentleslopebyhighscouringcapacityofthetorrentialflood.Debrisflowisturbulentbecauseofitshighflowvelocityinsomecircumstancesa…     

Pulsed export of carbon in the north-western Mediterranean Sea

The short term(hourly scale) variability of heterotrophic prokaryote(HP) vertical distribution and respiratory activity,was investigated in the north-western(NW) Mediterranean Sea.HP vertical distribution was determined on board by flow cytometry analysis of seawater samples collected by series of CTD casts.Cell counts and viability were determined for all samples.HP respiratory rates were determined later in the laboratory from filtered seawater samples(23 dm³) from 300-1 150-m depth...     

花岗岩热液蚀变发生在南非威特沃特斯兰德盆地沉积后的成因证据

与威特沃特斯兰德和芬特斯多普超群含金变沉积岩空间上共存的花岗岩热液蚀变是岩浆后期形成的还是后来热液活动的产物？为帮助解决这个争论，本文对两个典型的蚀变花岗岩中以及中兰德群（威特沃特斯兰德超群）含金的金伯利矿层和不整合上覆的芬特斯多普接触带中蚀变产物的碳同位素和流体包裹体成分进行了研究。蚀变花岗岩中热液碳结核的δ＾１３Ｃ（－２５．７‰￣－３６．０‰）和芬特斯多普接触带露头中结核状碳（小污斑）（－２０     

Whole-bird models for the magnetic cleansing of oiled feathers

Iron powder, a promising dry-cleansing agent for oiled feathers where both the contaminant and the cleansing agent may be harvested magnetically, has been tested on the plumage of whole-bird models. The breast and back plumage of Mallard Duck (Anas platyrhynchos) and Little Penguin (Eudyptula minor) carcasses were patch-contaminated with commercial-grade engine oil, three different crude oils, and an oil/seawater emulsion. The plumage was then subjected to a magnetic cleansing protocol. The contaminant removal was assessed gravimetrically and was found to reflect the outcomes for a previously reported in vitro study using feather clusters. Between 92-98% of the contaminants, and effectively all of the cleansing agent, were removed from the feathers.     

机械式速度和高度计算器

1.前言根据雷达资料确定风暴的速度和高度时,通常是先测出雷达显示器或地图上的距离,然后根据所测得的距离和回波移动时间,再用手工、计算尺或电子计算器计算速度或高度。这个过程大体分为两步:测量和计算。本文所介绍的速度和高度计算器实质上将这个过程合并为一步。距离一经测出,同时也就对回波移动时间或仰角算出了速度或高度。这种计算器只是用机械式的两脚规测量距离,并加上了时标和速度线,     

基于高质量DTM的数字正射像片生成

本文介绍生成正射像片的一种新方法。它采用的一种数字地形模型，由栅格数据和矢量数据两者组成，如断裂线。这种方法克服了在大比例尺地图中由于简单栅格ＤＴＭ的精度不高而引起的地貌移位问题。