Optimization of geothermal water exploitation in Xinji,Hebei Province,P.R.China

Geothermal with features of large reserves and non-pollution has been one of the most important energy. China has significant geothermal resources. There are rich hydrothermal resources in Xinji, which has been in development for 5 years. However, hot water continues to decrease because of extensive exploitation and utilization. We selected exploration area as study area, build a set of numerical models of Guantao formation on the basis of actual geological conditions. We get the distribution of hydraulic conductivity from 1.7 m/d to 1.9 m/d by parameter inversion using historical water level monitoring data, and simulation effect is good. We calculate the maximum permissible exploitation under the limitation of 200 m in depth in 50 years which is about 2.2 million m3/a. The results will provide theoretic support for plan making of geothermal exploitation.

Analysis on Chinese Talent Loss Status from the Higher Education Perspective

In recent years, selection range of Chinese students for institutions of higher education is no longer limited to domestic range, with the rise of studying abroad, an increasing number of undergraduate and graduate students choose to go to the overseas for expansion of knowledge.This phenomenon has both advantages and disadvantages,on the one hand, it can promote the cultural exchange between countries,but on the other hand, the higher talent loss on China＇s economy caused great damage.For China＇s higher education workers and researchers, our research scope is not limited to the cultivation of the higher talents, and it also considers how to cultivate talent substantial contribution to economic civilization construction of the motherland without loss to foreign countries.This paper aims to analyze the current situation of higher talent loss in China from the perspective of higher education, and carries on the brief analysis on how to deal with this situation.

SHRIMP U-Pb dating for a K-bentonite bed in the Tieling Formation,North China

A SHRIMP U-Pb zircon age of 1437±21 Ma was obtained for a recently discovered K-bentonite bed in the Tieling Formation,situated northeast of Beijing at the boundary between Liaoning and Hebei provinces,on the northern margin of the North China Craton(NCC).The SHRIMP U-Pb age places Tieling Formation near the end of the Calymmian Period of the early Mesoproterozoic Era.In addition,a SHRIMP U-Pb zircon date of 1372±18 Ma was acquired for K-bentonite beds in the overlying,dark-shale-dominated Xiamaling Formation from the same location northeast of Beijing.This date assigns a similar Mid-Mesoproterozoic(Ectasian Period) age for the Xiamaling Formation,as have previously determined dates from other sections northwest of Beijing.These dates indicate that the Tieling and Xiamaling formations,as well as the related succession in the eastern part of the Yanshan Mountains,represented by the well-known Meso-to Neoproterozoic standard section in Jixian,can be correlated well with sections northwest of Beijing in the western part of the Yanshan Mountains.In other words,the boundary between the Calymmian and Ectasian periods in the northern parts of the NCC is marked by the unconformity between the Tieling and Xiamaling formations in the northern NCC.This boundary was previously ascribed to the "Qinyu Orogeny" and thought to be of Grenville age.In this regard,the conventional "Qinyu Orogeny" should now be regarded as a short-lived regional uplift during Early Mesoproterozoic time,rather than a result from the Grenvillian assembly of the NCC to the Rodinia Supercontinent(～1.0 Ga).

Mineralogical and geochemical features of sulfide chimneys from the 49°39′E hydrothermal field on the Southwest Indian Ridge and their geological inferences

During January–May in 2007,the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR).This was also the first active hydrothermal field found along an ultraslow-spreading ridge.We analyzed mineralogical,textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E field.Chimney samples show a concentric mineral zone around the fluid channel.The mineral assemblages of the interiors consist mainly of chalcopyrite,with pyrite and sphalerite as minor constitunets.In the intermediate portion,pyrite becomes the dominant mineral,with chalcopyrite and sphalerite as minor constitunets.For the outer wall,the majority of minerals are pyrite and sphalerite,with few chalcopyrite.Towards the outer margin of the chimney wall,the mineral grains become small and irregular in shape gradually,while minerals within interstices are abundant.These features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic Ridge.The average contents of Cu,Fe and Zn in our chimney samples were 2.83 wt%,45.6 wt% and 3.28 wt%,respectively.The average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively,higher than the massive sulfides from most hydrothermal fields along mid-ocean ridge.The rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sedimentstarved mid-ocean ridge,with the enrichment of light rare earth elements but the weak,mostly negative,Eu anomaly.This is attributed to the distinct mineralization environment or fluid compositions in this area.

Seasonal variations in the Sr-Nd isotopic compositions of suspended particulate matter in the lower Changjiang River:Provenance and erosion constraints

Suspended particulate matter samples were collected monthly for more than 2 years in Nanjing,China to examine seasonal changes in the Sr-Nd isotopic compositions of the lower Changjiang River(CR).The results indicate that the 87Sr/86Sr ratios of the samples ranges from 0.725352 to 0.738128,and the values ofεNd(0)ranges from-10.55 to-12.29.The Sr-Nd isotopic compositions show distinct seasonal variations.The samples had lower 87Sr/86Sr ratios and higherε Nd(0)values during the flood season than the dry seasons.The seasonal variations primarily reflect the controls of provenance rocks and erosion in different sub-catchments.The relative decrease in 87Sr/86Sr ratios and the increase inε Nd(0)values during the flood season may reflect an increasing in the mechanical erosion rate in the upper basin and the contribution of more sediment from the upper reaches.The end member values of 87Sr/86Sr andε Nd(0)of the samples were 0.728254 and?11.26,respectively.

Levels and distribution of polychlorinated biphenyls in the atmosphere close to Chinese Great Wall Station, Antarctica: Results from XAD-resin passive air sampling

Antarctica is an important research region for assessing persistence and long-range atmospheric transport (LRAT) of persistent organic pollutants (POPs). In this study, XAD-resin passive air sampling was conducted near the Chinese Great Wall Station, Antarctica, during a one-year sampling period in 2009-2010. The air concentrations of polychlorinated biphenyls (PCBs) were at a very low level, with total PCBs in the range of 26.74-45.08 pg m 3. PCB profiles were dominated by tetra-PCBs, tri-PCBs and di-PCBs, indicating LRAT was responsible for the pollutants in the Antarctic atmosphere. The sampling site near the Chinese Great Wall Station did not show higher PCB levels than the other sites, suggesting that PCB sources associated with the Great Wall Station were negligible. PCB-11 is a non-Aroclor congener, which has specific sources compared to other Aroclor PCB congeners. PCB-11 was observed in all air samples, with an average concentration of 1.22 pg m 3. To our knowledge, this study is the first investigation of PCB levels and distribution in the atmosphere around the Chinese Great Wall Station, Antarctica.