Triple oxygen isotope constraints on the origin of ocean island basalts

Understanding the origin of ocean island basalts(OIB) has important bearings on Earth's deep mantle.Although it is widely accepted that subducted oceanic crust, as a consequence of plate tectonics, contributes material to OIB's formation, its exact fraction in OIB's mantle source remains ambiguous largely due to uncertainties associated with existing geochemical proxies. Here we show, through theoretical calculation, that unlike many known proxies, triple oxygen isotope compositions(i.e.D^(17 )O) in olivine samples are not affected by crystallization and partial melting. This unique feature, therefore, allows olivine D^(17 )O values to identify subducted oceanic crusts in OIB's mantle source. Furthermore, the fractions of subducted ocean sediments and hydrothermally altered oceanic crust in OIB's mantle source can be quantified using their characteristic D^(17 )O values. Based on published D^(17 )O data, we estimated the fraction of subducted oceanic crust to be as high as 22.3% in certain OIB, but the affected region in the respective mantle plume is likely to be limited.

Analysis on the Phase Frequency Characteristic of Soil Impedance

Soil is a typical porous media and its impedance characteristic directly determines the performance of grounding system. Soil phase frequency characteristic measurements were carried out on various soil types and water content. This paper finds that the impedance angle of soil specimen presents a capacitive performance when power frequency (f) is low. As the frequency increases, soil impedance angle goes up rapidly. Furthermore the frequency characteristic while f > 1000 Hz is distinct in terms of different water content. In particular, at low moisture content, soil impedance angle would be higher than 0?, that is, the inductive component is obvious. The study result indicates that porous media possesses the unique conductivity property dif-ferent from conductor and solution. Its mechanism needs further study.

Analysis of cancer incidence and mortality in 2010 to the residents of Hai’an county, Jiangsu Province, China

Objective: The aim of the study was to analyze the incidence, mortality and their impact factors and changing trends of malignant tumors in 2010 in the residents of Hai’an county, Jiangsu Province, China. Methods: Using the information of incidence, death registration information database and population data of malignant tumors in 2010 in the residents of Hai’an county, the incidence, mortality, accumulation incidence rates, and truncated incidence rate of malignant tumors were statistically analyzed. Results: The crude incidence, China standardized and world standardized incidence rates of malignant tumors in 2010 in Hai’an county were 281.53 per 100000 persons, 174.96 per 100 000 persons, and 175.14 per 100000 persons, respectively. The cumulative incidence rate from aged 0 to 64 years, the cumulative incidence rate from aged 0 to 74 years and the truncated incidence rate from aged 35 to 64 years were 6.85%, 15.39%, and 193.26 per 100000 persons, respectively. The rough mortality rate, China standardized and world standardized incidence rates were 234.11 per 100000 persons, 145.30 per 100000 persons, and 144.77 per 100000 persons, respectively. The top five cancers in the spectrum of cancer incidence were respectively esophageal cancer, lung cancer, stomach cancer, liver cancer, and colorectal cancer. The top four cancers in the spectrum of cancer death were consistent with the spectrum of cancer incidence. The 5th cancer in the spectrum of cancer death was pancreatic cancer. The incidence and mortality of various age groups were at a low level before 35-year-old age group. The incidence of female was slightly higher than that of male. But the incidence and mortality from the age group of 50 showed "suddenly" upward trend with age. The incidence and mortality of male were significantly higher than those of female. The ratios of male to female of incidence and mortality were 1.52:1 and 1.67:1, respectively. Conclusion: Residents over the age of 50, especially males, are high-risk groups who are exposed to certain risk factors. They should be the key objects of prevention and treatment of malignant tumors.

Study on the Influence of Grounding Conductor Structure on Its Grounding Impedance Spectrum Response

The grounding diagnosis of pole and tower plays an important role, and the tower is characterized by its unique characteristics. It is necessary to develop a new method for the diagnosis of pole and tower. Frequency diagnosis is applied in many aspects, so it is necessary to analyze the frequency response characteristics of pole and tower. The influence of the frequency response of pole and tower on the radius of the pole and the soil resistivity is analyzed under three different grounding structures using CDEGS software, and the differences and similarities of spectral response under different structures are discussed.