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641.
Sungkyun SHIN Young Min NOH Kwonho LEE Hanlim LEE Detlef MLLER Y.J.KIM Kwanchul KIM Dongho SHIN 《大气科学进展》2014,31(6):1417-1426
The vertical distribution of single scattering albedos (SSAs) of Asian dust mixed with pollutants was derived using the multi-wavelength Raman lidar observation system at Gwangju (35.10°N,126.53°E).Vertical profiles of both backscatter and extinction coefficients for dust and non-dust aerosols were extracted from a mixed Asian dust plume using the depolarization ratio from lidar observations.Vertical profiles of backscatter and extinction coefficients of non-dust particles were input into an inversion algorithm to retrieve the SSAs of non-dust aerosols.Atmospheric aerosol layers at different heights had different light-absorbing characteristics.The SSAs of non-dust particles at each height varied with aerosol type,which was either urban/industrial pollutants from China transported over long distances at high altitude,or regional/local pollutants from the Korean peninsula.Taking advantage of independent profiles of SSAs of non-dust particles,vertical profiles of SSAs of Asian dust mixed with pollutants were estimated for the first time,with a new approach suggested in this study using an empirical determination of the SSA of pure dust.The SSAs of the Asian dust-pollutants mixture within the planetary boundary layer (PBL) were in the range 0.88-0.91,while the values above the PBL were in the range 0.76-0.87,with a very low mean value of 0.76 ± 0.05.The total mixed dust plume SSAs in each aerosol layer were integrated over height for comparison with results from the Aerosol Robotics Network (AERONET) measurements.Values of SSA retrieved from lidar observations of 0.92 ± 0.01 were in good agreement with the results from AERONET measurements. 相似文献
642.
As a conservative tracer, oxygen isotopes in seawater are widely used for water mass analysis, along with temperature and salinity. In this study, seawater oxygen-18 datasets in the Canada Basin during 1967–2010 were obtained from the four cruises of the Chinese National Arctic Research Expedition(1999, 2003, 2008, and 2010) and the NASA database. Fractions of sea ice meltwater and river runoff were determined from the salinity-18O system. Our results showed that the river runoff decreased from the south to the north in the Canada Basin. The enhanced amount of river runoff observed in the southern Canada Basin may originate from the Mackenzie River, transported by the Beaufort Gyre. The river runoff component showed maximum fractions during 1967–1969, 1978–1979, 1984–1985, 1993–1994, and 2008–2010, indicating the refresh time of the river runoff was 5.0–16.0 a in the Canada Basin. The temporal variation of the river runoff was related to the change of the Arctic Oscillation(AO) index, suggesting the freshwater stored in the Canada Basin was affected by surface sea ice drift and water mass movement driven by atmospheric circulation. 相似文献
643.
210Pb was measured during the 3rd Chinese National Arctic Research Expedition cruise to investigate its spatial pattern in the western Arctic Ocean, as well as its relation with the thermocline in the Canadian Basin. The specific activities varied from 0.04 to 2.72, 0.013 to 4.37, and 0.1 to 4.85 Bq/m3 for dissolved, particulate, and bulk 210Pb, respectively, corresponding to respective averages of 0.65, 0.43, and 1.08 Bq/m3. In the Canadian Basin, the minimum 210Pb activities occurred in the thermocline, which was characterized by low temperature of-1.52°C and salinity of 33.1. Combining the spatial distribution of 210Pb and hydrographical characteristics in the western Arctic Ocean, this scenario was ascribed to the effective scavenging of 210Pb when the Pacific water flowed across the Chukchi Shelf. Quantitatively, this interpretation was supported by both the shorter residence times and higher scavenging efficiencies(SE) of dissolved 210Pb over the Chukchi Shelf. The highest SE values were observed in the Herald Shoal and bottom waters over the slope. 相似文献
644.
To make a curvilinear motion in the horizontal plane is one of the most contents for realizing the maneuverability of the supercavitating vehicle. It is significant to achieve the controllability and maneuverability of the vehicle in three dimensions both theoretically and practically on research. Models of angle of attack, gravity and inertial force effects on the supercavity in the horizontal curvilinear motion are established, respectively. The supercavity is simulated based on these models in combination with Logvinovich model and the unsteady gas-leakage rate model at the given ventilation rate, and the effect of the inertial force on it is analyzed numerically. Results show that the maximum deviation of the center line of the cross section of supercavity towards the outward normal direction of its trajectory increases as the cavitation number or curvature radius decrease and always occur in the tail because of the increase of inertial effects along the axis of supercavity from the cavitator when other models and flow parameters are constant for the given trajectory curvature. For the variable curvature, the supercavity sheds due to its instability caused by the time-varying angle of attack. The deviation increases along the length of supercavity if the curvature remains the same sign. 相似文献
645.
在目前的钻孔地质编录中,往往侧重于地层岩性特征的描述,而构造现象的描述则相当粗略,不能为构造分析提供必要的依据。为弥补这个缺陷,笔者根据鸡西永庆煤田、合作煤田等煤田的实际所见,提出看法,共同探讨。地层的重复和缺失作为判断断层的重要标志已为广大地质人员所熟知,本文不再论述,现着重论述断层带中碎裂岩石的特征及断层带的特点。 相似文献
646.
Response of microbial community to petroleum stress and phosphate dosage in sediments of Jiaozhou Bay,China 总被引:1,自引:0,他引:1
ZHAO Yangguo CHEN Min BAI Jie LI Xinwei Farhana Zulfiqar and WANG Qianli 《中国海洋大学学报(英文版)》2014,13(2):249-256
The dynamic microcosms were used to evaluate the effect of oil spills on microbial ecological system in marine sediment and the enhancement of nutrient on the oil removal. The function and structure of microbial community caused by the oil pollution and phosphate dosage were simultaneously monitored by dehydrogenase activity assay and PCR-denaturing gradient gel electrophoresis (DGGE) techniques. The results indicated that the amount of total bacteria in all dynamic microcosms declined rapidly with incubation time. The number of petroleum-degrading bacteria and the activity of sediment dehydrogenase were gradually enhanced by petroleum in the oil-treated microcosms, while they both showed no obvious response to phosphate dosage. In comparison, phosphate spiked heterotrophic bacteria and they showed a significant increase in amount. DGGE profiles indicated that petroleum dosage greatly changed community structure, and the bacteria belonged to class Deltaproteobacteria, and phyla Bacteroidetes and Chlorobi were enriched. This study demonstrated that petroleum input greatly impacted the microbial community structure and consequently the marine sediment petroleum-degrading activity was enhanced. Phosphate dosage would multiply heterotrophic bacteria but not significantly enhance the petroleum degradation. 相似文献
647.
648.
合理地设计地表移动观测站,是准确预测矿山开采沉陷引起地表移动、变形的基础。本文分析变形观测站设计方法,对该方法做了详尽剖析。结合淮南矿区的地质以及地表综合条件,设计适合淮南地区地表移动变形观测站设计的算法模式,并采用VB和MapObjects进行了实现。最后,以淮南市潘北矿区地表移动观测站设计为实验对象,结果表明:采用软件设计的地表移动观测站,能够有效反映沉陷区特征,且具有高效、可视化特点。 相似文献
649.
650.
为了做好政府的公共气象服务,改善当前服务产品形式单一的局面,作者重点研究了MICAPS软件下的风云卫星云图实现在线浏览和定量分析的关键技术。首先结合ArcGIS Engine完成了该类云图向多波段栅格img格式的转换,生成了自带颜色和投影坐标的栅格云图。然后采用ArcGIS Server构建了栅格云图的网络发布平台,实现了云图在Web环境下的发布、查询和浏览,并采用GIS统计分析方法,提出并实现了云图的定量统计与分析。经测试,该平台可高效地运行于当前Web环境,完全能够适应当前带宽传输及满足主流电脑浏览和分析的需要。该平台应用到包头市公共气象服务系统中,使当地气象局在公共气象服务平台的建设方面迈进了一大步,为公众了解气象和预报员制作气象预警预报提供了一个气象信息辅助决策平台。 相似文献