Mariner 9 ultraviolet spectrometeer experiment: 1971 Mars' dust storm     

Kevin Pang  Charles W. Hord 《Icarus》1973,18(3):481-488

The Mariner 9 ultraviolet spectrometer observed the brightness of a region on the south polar cap centered at approximately ?87°S, 10°W. Measurements taken at various incidence and emission angles (i and ?) show that the brightness increased with decreasing air mass, ≈(sec i + sec ?). The observed intensity consists primarily of a component reflected from the cap and twice-attenuated by the atmosphere and a component diffusely reflected from the atmosphere. The diffusely reflected component was determined from nearby observations of non-polar regions at the same incidence and emission angles and was substrated from the total intensity. Inversion of the intensity difference using a formula analogous to the Bouger-Langley law yielded the optical thickness of the atmosphere. The dust cloud over the polar cap was moderately thick between November 26 and December 2, 1971. At this time the optical thickness was near unity, and it decreased approximately linearly with time, reaching a value close to that of a Rayleigh atmosphere by mid-February. The optical thickness showed little dependence on the wavelength during the early orbital observations. As the dust storm cleared, the atmospheric optical thickness exhibited increasingly strong inverse wavelength dependence. Particles large compared with the wavelength dominated the Martian dust storm. These particles are estimated to have a mean radius of about 2 μm.  相似文献   

海水中不同价态铬的测定     

黄华瑞  庞学忠 《海洋科学》1989,13(2):53-57

本文研究了用Aliguat-336萃取,无焰原子吸收分光光度法测定海水中不同价态铬的方法。该方法有较好的精密度,变动系数为6.0%。回收率在80%左右,其特征量为6.3×10~(14)g,较好地应用于海水中不同价态铬的测定。  相似文献   

水面油膜微波辐射特性实验室测量与分析     

逄爱梅  孙元福 《海岸工程》2003,22(4):36-41

要实现利用微波辐射计对海面溢油的厚度等参数进行遥感监测，必须先对水面油膜的微波辐射特性进行研究，以便为传感器的设计和遥感资料的解译提供依据。在实验室条件下，利用“灰体室”的环境条件及测量方法，测试了原油、燃料油和食用植物油膜的微波发射率与油膜厚度之间的关系，并对测量结果进行分析和讨论。为实际应用提供技术资料。  相似文献   

长江及其河口区铬的形态     

黄华瑞  庞学忠 《海洋科学集刊》1986,(27):115-124

近年来，海水中痕量金属的形态引起了人们的重视，尤其对河口痕量金属的研究更为关注。江河及河口是污染物排放的重要渠道，而铬是海水中的重要污染物之一，由于各种理化环境的变化，它在河口区常常发生形态的转移，对生物毒性也产生了差异，因而引起了海洋化学家的兴趣。许多学者为此进行了研究，并取得了有意义的结论。 长江是我国最大的河流，沿岸有许多工业城市。黄浦江是其人海前的重要支流，上海市的工业废水和城市污水均由此流到河口区。为此我们试图研究铬在长江运移过程中不同形态的变化。 我国研究河口海域铬的论文甚少，作者曾进行了渤海湾海水中铬的研究，吴瑜端(1978)对长江口海域底质和底层水中的Cu、Cr、Hg进行了研究，然而对长江口水中铬的形态研究则未见报道。  相似文献   

大兴安岭地区森林沼泽生态系统火生态效应研究   总被引：1，自引：0，他引：1  

杨永兴  杨玉娟  庞志平  杨永海 《海洋与湖沼》1995,26(6):610-618

于１９９０年５月－１９９３年１０月，为查清火灾对森林沼泽生态系统，采取野外面上考察与定位观测，野外实验与室内分析化验，定性分析与定量分析相结合的方法，在阿木尔林业局长缨林场、红旗林场选取观测点进行森林沼泽生态系统火生态效应的对比观测与实验。  相似文献   

Experimental study on stability of sunken large diameter cylindrical structure on sandy seabed during construction period     

Qin Chongren  Pang Hongli  Li Shisen  Zhang Wei 《海洋学报(英文版)》2002,21(4):581-595

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｌａｒｇｅｄｉａｍｅｔｅｒｃｙｌｉｎｄｒｉｃａｌｓｔｒｕｃｔｕｒｅｉｓｏｆｔｅｎｕｓｅｄａｓｔｈｅｗｈａｒｆａｎｄｔｈｅｂｒｅａｋｗａｔｅｒｓｔｒｕｃｔｕｒｅｏｆｈａｒｂｏｒ.Ｓｉｎｃｅｉｔｔａｋｅｓｓｏｍｅｔｉｍｅｔｏｆｉｌｌｍａｔｅｒｉａｌｉｎｔｏｔｈｅｃｙｌｉｎｄｅｒａｆｔｅｒｔｈｅｃｙｌｉｎｄｅｒｓｈｅｌｌｉｓｓｕｎｋｅｎｔｏｔｈｅｓｅａｂｅｄ ,ｔｈｅｓｔａｂｉｌｉｔｙｏｆｔｈｅｃｙｌｉｎｄｅｒｂｅｃｏｍｅｓｃｏｎｔｒｏｌｃｏｎｄｉｔｉｏｎｆｏｒｔｈｅｓａｆ…  相似文献   

太湖北岸风浪谱的特征分析   总被引：6，自引：0，他引：6  

逄勇  濮培民  胡维平  乔树梁 《海洋与湖沼》1996,27(5):531-537

利用１９９２年在太湖北岸马迹山地区测得的浅水风风浪资料，采用ＦＦＴ方法求算风浪频谱，对谱结构特征的分析表明，观测到的风浪谱在平衡范围谱值按－４．０幂指数衰减，风浪谱形状与文圣常给出的理论结果比较接近。另外，分析以风要素为参量得到的无因次化频谱可以看出，观测谱基本满足谱的相似律。  相似文献   

颗粒物质和微量金属在东海北部的沉积通量   总被引：1，自引：1，他引：1       下载免费PDF全文

詹滨秋  黄华瑞  庞学忠  李鹏程  宋金明  任建伟 《海洋与湖沼》1993,24(1):51-58

于1990年运用沉积物捕捉器采样,实测了东海北部(32.00°N,126.00°E)海域颗粒物质和微量金属(Cu,Pb,Zn,Cr,Fe,Mn和Al)的海洋垂直通量。结果表明,颗粒物质的沉积通量随深度和季节而变化,明显地受上升流的影响。沉积的颗粒物质以0.45—63μm的小颗粒为主;Cu和Zn主要以有机物形式作垂直转移,Pb,Cr,Fe和Mn主要以弱键结合形式作垂直转移,Al则以硅酸盐的形式作垂直转移。沉积物中,颗粒Cu,Fe,Mn和Al以0.45—63μm的颗粒为主;颗粒Pb和Cr以大于63μm的颗粒为主;0.45—63μm和大于63μm的颗粒Zn在沉积物中占相近的比例。  相似文献   

Experimental investigation of secondary oil migration along subtle pathways: A mechanism for hydrocarbon accumulation in lenticular basinal turbidite reservoirs     

Dongxia ChenXiongqi Pang  Keyu LiuJun Zhang  Rucai Zhang 《Journal of Geochemical Exploration》2009

  相似文献   

New apatite fission track evidence from the northern Qiangtang terrane reveal two‐phase evolution of central Tibet     

Jiawei Zhang  Yalin Li  Ming Xu  Jingen Dai  Xinyu Qian  Zhongpeng Han  Huiping Zhang  Jianzhang Pang 《地学学报》2021,33(1):95-108

The growth of central Tibet remains elusory, albeit important in evaluating different topographic growth models accounting for the Tibetan Plateau development. Thermochronological records in the northern Qiangtang terrane (QT) provide valuable information for investigating the cooling and exhumation history in central Tibet. New apatite fission track data, assisted by inverse thermal modelling, reveal two stages of accelerated cooling. The Early Cretaceous cooling is related with refrigeration of the QT and exhumation probably induced by crustal shortening. The Eocene‐Oligocene renewed cooling reflects the far‐field contraction after the onset of the India‐Asia collision and Cenozoic crustal shortening deformation in the QT, coupled with thermal relaxation and transient lithospheric removal. Our data support models indicating that Cretaceous crustal shortening produced a thickened crust in the QT, whereas the present‐day elevation was established during Eocene‐Oligocene due to crustal shortening, continental subduction and lithospheric delamination.  相似文献