Distribution and Sources of Dissolved and Particulate Heavy Metals (Mn,Co, Ni,Cu, Zn,Cd, Pb) in Masan Bay,Korea

Ocean Science Journal - In this study, we investigated the spatial and temporal distribution and sources of dissolved and particulate heavy metals in Masan Bay, an area that for a long time has...     

Object‐oriented tracking of thematic and spatial behaviors of urban heat islands

Modeling thematic and spatial dynamic behaviors of urban heat islands (UHIs) over time is important for understanding the evolution of this phenomenon to mitigate the warming effect in urban areas. Although previous studies conceptualized that a UHI only has a single life cycle with spatial behaviors, a UHI can be detected to appear and disappear several times periodically in terms of thematic and spatial integrated behaviors. Such multiple behaviors have not yet been illustrated with proof or evidence. This study conceptualizes a UHI as an object which has thematic and spatial behaviors simultaneously and proposes several graphs to depict periodic life‐cycle transitions triggered by behaviors. The conceptualized behaviors have been modeled and implemented in an object‐relational database management system and temperature readings collected from numerous weather stations were interpolated as temperature images per hour. The results of this study indicate that the model could track the spatial and thematic evolution of UHIs continuously and reveal their periodical patterns and abnormal cases.     

单多普勒天气雷达反演风场高原低纬区域同化应用

为了改善低纬高原地区天气预报水平,利用WRF(Weather Research and Forecasting)模式及其变分同化系统进行雷达VAD(Velocity Azimuth Display)反演风场资料同化试验。通过设计不同的试验方案,对2009年6月30日00:00至7月1日00:00发生在云南的一次强降水过程进行数值模拟和对比分析,结果表明:同化VAD反演风场资料后对区域模式的风矢量初始场有明显影响。同化系统能把雷达反演风场信息有效地引入模式初始场,改善强降水区域的水汽输送和风场辐合强度;同化VAD反演风场资料后对区域模式累计降水预报有一定改进作用。从长时间累计降水量定量检验结果看,具体表现为25mm以上量级的降水准确率明显提高、漏报率下降,预报偏差更趋合理。不同的同化试验方案之间的模拟结果差异较大。同化频率越高、同化持续时间越长,对区域模式初始场和预报场的影响越明显。但同化持续时间不宜过长,否则可能导致系统移速过快、降水强度偏大、空报率增加等异常。     

基于层次分析法的大连区域雷灾易损性评价

根据大连地区近6年雷电灾害资料,40年雷暴资料,以大连地理、气候环境为背景,通过计算指标权重,采用层次分析法对大连区域雷灾易损性进行评价,并通过一致性检验。结果显示,金州新区属于极高风险区域,瓦房店属于高风险区域,大连、普兰店、庄河属于低风险区域,旅顺属于极低风险区域。结果表明雷灾区域易损性分析不仅取决于样本区域的自然雷暴日,还与样本区域的经济发展情况、人口密度、历史灾害等多方面因素有关,各指标影响权重也并非相同。采用层次分析法进行区域雷灾评价研究,能够有效减少人为因素,为防雷减灾提供了依据。     

Soil erosion of unpaved loess roads subjected to an extreme rainstorm event: a case study of the Jiuyuangou watershed on the Loess Plateau,China

Rainfall can cause serious soil loss in the Loess Plateau hilly and gully region, but little focus has been placed on the extreme rainstorm effects on unpaved loess road soil erosion. A field survey method was used to investigate the erosional effects of the "7·26" heavy rainfall event on unpaved loess roads in the Jiuyuangou watershed of the Loess Plateau, China. The results showed that the average and maximum widths of the eroded gullies that formed on the unpaved roads were 0.65-1.48 m and 1.00-3.60 m, respectively. The average and maximum depths of theeroded gullies were 0.42-1.13 m and 0.75-4.30 m, respectively. The average width-to-depth ratio was 1.31, indicating that the widening effect was greater than the downcutting effect in the eroded gullies. In addition, the gully density ranged from 0.07 to 0.29 m m~(-2), and the road surface dissection degree ranged from 0.03 to 0.41 km~2 km~(-2). Eroded gullies generally developed at the slope toe of the cut bank side. The average eroded gully width and depth at turns in the road were 1.47-2.64 times and 1.30-3.47 times greater, respectively, than those in other road sections. The road erosion modulus increased from the upper section to the lower section of the roads. The average road erosion modulus of the study catchment was 235,000 t km~(-2). Turns in the road were associated with collapses, sinkholes and other gravitational erosion phenomena. The amount of road erosion under extreme rainfall conditions is mainly related to the interactions among road length, width, slope and soil bulk density. Our results provide a useful reference for developing further measures for preventing road erosion on the Loess Plateau.     

Molecular Identification and Expression Analysis of Carbonic Anhydrase VII in Pufferfish (Takifugu rubripes)

Ocean Science Journal - A carbonic anhydrase VII gene, encoding 277 amino acids, was identified in the intestinal tissue of pufferfish (Takifugu rubripes). The translated protein with an 833-bp...     

The galaxy luminosity function in the LAMOST Complete Spectroscopic Survey of Pointing Area at the Southern Galactic Cap

We present optical luminosity functions(LFs) of galaxies in the~(0.1) g,~(0.1) r,~(0.1) i bands, calculated using data in~40 deg~2 sky area of the LAMOST Complete Spectroscopic Survey of Pointing Area(LaCoSSPAr) in the Southern Galactic Cap. Redshifts for galaxies brighter than r = 18.1 were obtained mainly with LAMOST. In each band, LFs derived using both parametric and non-parametric maximum likelihood methods agree well with each other. In the0.1 r band, our fitting parameters of the Schechter function are φ_*=(1.65 ± 0.36) × 10~(-2) h~3 Mpc~(-3), M_*=-20.69 ± 0.06 mag and α =-1.12 ± 0.08,which agree with previous studies. Separate LFs are also derived for emission line galaxies and absorption line galaxies. The LFs of absorption line galaxies show a dip at~(0.1) r ~18.5 and can be fitted well by a double-Gaussian function, suggesting a bimodality in passive galaxies.     

Tracking climate change in Central Asia through temperature and precipitation extremes

Journal of Geographical Sciences - Under the impacts of climate change and human activities, great uncertainties still exist in the response of climate extremes, especially in Central Asia (CA). In...     

Quantitative Analysis of Micro-structural Changes in a Bituminous Coal After Exposure to Supercritical CO2 and Water

Natural Resources Research - High-volatile bituminous coal samples were reacted in deionized water with supercritical CO2 (ScCO2–water) under simulated in situ pressure and temperature...     

Underwater autonomous manipulation for intervention missions AUVs

Many underwater intervention tasks are today performed using manned submersibles or remotely operated vehicles in teleoperation mode. Autonomous underwater vehicles are mostly employed in survey applications. In fact, the low bandwidth and significant time delay inherent in acoustic subsea communications represent a considerable obstacle to remotely operate a manipulation system, making it impossible for remote controllers to react to problems in a timely manner.Nevertheless, vehicles with no physical link and with no human occupants permit intervention in dangerous areas, such as in deep ocean, under ice, in missions to retrieve hazardous objects, or in classified areas. The key element in underwater intervention performed with autonomous vehicles is autonomous manipulation. This is a challenging technology milestone, which refers to the capability of a robot system that performs intervention tasks requiring physical contacts with unstructured environments without continuous human supervision.Today, only few AUVs are equipped with manipulators. SAUVIM (Semi Autonomous Underwater Vehicle for Intervention Mission, University of Hawaii) is one of the first underwater vehicle capable of autonomous manipulation.This paper presents the solutions chosen within the development of the system in order to address the problems intrinsic to autonomous underwater manipulation. In the proposed approach, the most noticeable aspect is the increase in the level of information transferred between the system and the human supervisor.We describe one of the first trials of autonomous intervention performed by SAUVIM in the oceanic environment. To the best knowledge of the authors, no sea trials in underwater autonomous manipulation have been presented in the literature. The presented operation is an underwater recovery mission, which consists in a sequence of autonomous tasks finalized to search for the target and to securely hook a cable to it in order to bring the target to the surface.