Stellar Abundance and Galactic Chemical Evolution through LAMOST Spectroscopic Survey

A project of a spectroscopic survey of Galactic structure and evolution with a Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) is presented. The spectroscopic survey consists of two observational modes for various targets in our Galaxy. One is a major survey of the Milky Way aimed at a systematic study of the stellar abundance and Galactic chemical evolution through low resolution (R=1000-2000) spectroscopy. Another is a follow-up observation with medium resolution (R = 10000) spectrographs aimed at detailed studies of the selected stars with different chemical composition, kinematics and dynamics.     

Differences in CO2-Water-Rock Chemical Reactions among 'Sweet Spot' Reservoirs: Implications for Carbon Sequestration

The Lucaogou Formation, located in the Jimsar Sag, Junggar Basin, NW China, has great potential for shale oil resources. In the process of CO₂-EOR(CO₂ enhance oil recovery), mineral dissolution, precipitation and transformation, leading to the local corrosion or blockage of reservoirs, have a significant influence on recovery. In this study, a combination of high-temperature and high-pressure laboratory experiments and coupled temperature/fluid-chemistry multifield numerica...     

Characteristics of algal blooms in the southern coastal waters of Korea

We have investigated the characteristics of algal blooms in relation to the marine environment since their first known occurrence in the southern coastal waters of Korea. The algal blooms occurred most frequently in Masan and Jinahe bays, suggesting that they were related to the development of anoxic water masses. Skeletonema costatum, Heterosigma akashiwo and Prorocentrum sp. commonly occurred as the dominant organisms causing the blooms in all regions, although the conditions of their appearance differed from place to place. Algal blooms in all regions were more likely to occur when precipitation ten days prior to the bloom was greater than the long-term mean values. However, the factors that relate to the development of the algal blooms in Gamak Bay differed depending upon the causative species while they were largely identical in Jinhae Bay, regardless of the species.     

The First Hadrosaurid Dinosaur from Southern China

A new hadrosaurid dinosaur,Nanningosaurus dashiensis gen.et sp.nov.,is described based on an incomplete skeleton from the Late Cretaceous red beds of the Nalong Basin,Guangxi,southern China.Diagnostic features for the new taxon include the presence of a tall and sharply peaked dorsal process of the maxilla with reduced process of the jugai and a distinct lacrimal facet,gracile humerus with low,rounded deltopectoral crest,mandibular condyle of the quadrate transversly broad with reduced paraquadrate notch,dentary tooth with sinuous median carina and subsidiary ridge,relatively few tooth positions,ischial shaft straight along most of its distance,but to curve dorsally and expand at the distal end before the ischial foot begins.Phylogenetic analysis suggests that Nanningosaurus dashiensis is a basal member of Lambeosanrinae.     

Deep electrical structures of Qinzhou-Fangcheng Junction Zone in Guangxi and seismogenic environment of the 1936 Lingshan M6(3/4) earthquake

The tectonic position of the southwest section of the Qinzhou Bay-Hangzhou Bay Tectonic Junction Zone(QHTJZ)can be determined by examining the Qinzhou-Fangcheng Junction Zone(QFJZ) in Guangxi. This zone is significant because it was the location of the largest earthquake ever recorded in the inland region of South China, specifically the 1936 Lingshan M6(3/4) earthquake in Guangxi. Therefore, this region serves as an optimal location for researching the origins of intraplate earthquakes in South...     

Prehistoric damaging earthquake promoted the decline of "Heluo Ancient State" in Early China

The emergence of the "Ancient State" is considered an important stage in the discourse on human civilizations.Based on its complex and hierarchical social structure,the Shuanghuaishu site of Henan Province is regarded as an "Ancient state",specifically the "Heluo Ancient State".The site is situated in the middle reaches of the Yellow River region and played a key role in prehistoric China.However,the reasons behind its decline are unclear.Here,we conducted an integrated investigation of the arch...     

Improved characterization of small "u" for Jacob pumping test analysis methods

Numerous refinements have been proposed to traditional pumping test analyses, yet many hydrogeologists continue to use the Jacob method due to its simplicity. Recent research favors hydraulic tomography and inverse numerical modeling of pumping test data. However, at sites with few wells, or relatively short screens, the data requirements of these methods may be impractical within physical and fiscal constraints. Alternatively, an improved understanding of the assumptions and limitations of Theis and, due to their widespread usage, Jacob analyses, leads to improved interpretations in data-poor environments. A fundamental requirement of Jacob is a "small" value of u = f(r(2)/t), with radial distance, r, and pumping time, t. However, selection of a too stringent (i.e., too low) maximum permissible u-value, u(max), results in rejection of usable data from wells beyond a maximum radius, r(max). Conversely, data from small radii, less than r(min), where turbulent- and vertical-flow components arise, can result in acceptance of inappropriate data. Usage of drawdown data from wells too close to the pumping well, and exclusion of data from wells deemed too far, can cause unrealistic aquifer transmissivity, permeability, and storativity determinations. Here, data from an extensive well field in a glacial-outwash aquifer in north-central Minnesota, USA, are used to develop a new estimate for u(max). Traditionally quoted values for u(max) range from 0.01 to 0.05. Our proposed value for Jacob distance-drawdown analyses is significantly higher with u(max) up to 0.2, resulting in larger allowable r(max)-values and a higher likelihood of inclusion of additional wells in such pumping test analyses.