Response of Japanese anchovy(Engraulis japonicus)to the Pacific Decadal Oscillation in the Yellow Sea over the past 400 a

Quantitative identification of long-term changes in the abundance of Japanese anchovy(Engraulis japonicus)in the Yellow Sea is particularly important for understanding evolutionary processes of the Yellow Sea ecosystem.Unfortunately,the driving mechanisms of climate variability on the anchovy are still unclear due to the lack of long-term observational data.In this study,we used the fish scale deposition rate in the central Yellow Sea to reconstruct the time series of the anchovy stock over the past 400 a.On this basis,we further explored the impacts of the Pacific Decadal Oscillation(PDO)on the anchovy.Our results show that the anchovy stock is positively correlated with the PDO on a decadal time scale.In addition,anchovy abundance was relatively high during1620–1860 AD(the Little Ice Age,LIA),though in a state of constant fluctuation;anchovy abundance maintained at a relatively low level after~1860 AD.In particular,followed by overfishing since the 1980 s,the anchovy stock has declined sharply.Based on these findings,we infer that fluctuations of the anchovy stock may be regulated by basin-scale“atmosphere–ocean”interactions.Nevertheless,the role of overfishing should not be ignored.

Summary of technology for a comprehensive geophysical exploration of gold mine in North China Craton

The North China Craton is the oldest continental block,and has suffered from large-scale lithospheric thinning and destruction,which in turn led to gold deposits in northern China.The decratonic gold deposits in the North China Craton became the most important gold deposits in China,and geophysical methods are key means to detect and discover gold deposits there.In this paper,based on the geological and petrophysical characteristics of the North China Craton,the geological model of the decratonic gold deposits is transformed into a geophysical model.At present,two methods of geophysical exploration of decratonic gold deposits are in use:rapid and efficient exploration on the scale of the ore concentration area,and large depth exploration on the scale of the deposit area.In detail,the airborne electromagnetic,magnetic and gravity methods are used to detect the shallow(1,500 m)anomaly area on the scale of the ore concentration area.Through the ground-controlled source electromagnetic and ground magnetotelluric methods,explorations for targets at significant depth(5,000 m)are carried out in the mining area.Then,taking the Liaodong ore concentration area as an example,geophysical methods are used to discover two prospecting areas around the Jianshanzi Fault in the Qingchengzi ore concentration area,Baiyun-Xiaotongjiapuzi deep prospecting area,and Qingchengzi deep prospecting area.Next,three prospecting areas are delineated around the Jixingou Fault in the Wulong mining area,Wulong deep prospecting area,Weishagou deep prospecting area,and Chang’an deep prospecting area.The anomalies in the ore concentration area and mining area are revealed by means of three-dimensional exploration methods,thereby providing technical support for the exploration of metal minerals such as decratonic gold deposits.

Cooling phenomena in blast furnace hearth

Cooling water provides the best protection for refractory in the blast furnace hearth. Stable and suitable water quality and abundant cooling water are the basis for long service life of the hearth. Some phenomena about cooling system in the commercial blast furnaces were described, and reasonable explanations of these phenomena were analyzed. The results show that increasing the amount of cooling water and reducing the inlet temperature of cooling water can increase the cooling effect significantly in the case of water scaling. Heat flux in the blast furnace hearth is the average heat flux of cooling stave, and the erosion of carbon brick is uneven. There is no direct connection between the actual erosion condition and the heat flux in the hearth. The change trend of thermocouple temperature and heat flux in the hearth can reflect whether the gaps exist among the bricks or not, providing an effective guidance for industrial production and the evaluation of safety state in the hearth. And, the film boiling will not occur in the normal cooling system in the blast furnace hearth.