U–Pb zircon age of the base of the Ediacaran System at the southern margin of the Qinling Orogen

Global abrupt climate change from Marinoan snowball Earth to greenhouse Earth, recorded as cap carbonate overlain on diamictite, had shed the first light on Cambrian bio-radiation. The most documented cap carbonate sections are typical with comprehensive d13 C negative values and ubiquitous sedimentary structures, such as tepee-like, sheet-crack etc., which are associated with successive glacial eustatic variation caused by isostatic rebound in shallow-water facies. Here we report a deepwater basinal cap carbonate section with strong negative δ^(13) C values in the southern margin of the Qinling Orogen,Heyu, Chengkou County, Chongqing in China, which consists of massive dolostone with abundant carbonaceous laminae. However, it lacks the sedimentary structure as mentioned above and is overlain by thin-bedded silicious shales and cherts. A K-bentonite bed was discovered within the base of cap carbonates, about 0.7 m above the top of the Marinoan diamictite. Magmatic zircons that were separated from the K-bentonite bed yield a SIMS concordia U–Pb age of 634.1 ± 1.9 Ma(1 r, MSWDCE= 0.31,ProbabilityCE= 1.000, n = 20). The age is in good agreement with previously reported TIMS U–Pb ages for the termination of Marinoan glaciation and provides ageochronological constraint for the Ediacaran successions in the Qinling Orogen.

Urban Rural Disparity in Westernization Related Cancers and the Increasing Incidence in Parallel with Socioeconomic Development and Urbanization from 2000-2015 among a Rural Chinese Population: An Observational Study

Abstract China used to have great urban rural disparity in socioeconomic development. Since the late 1980s, rapid socioeconomic development and urbanization have been taking place in rural settings. It is epidemiologically established that cancer scale and profile will transit as economy prospers and urbanization develops. However, there are few published studies reporting what changes are undergoing in cancer pattern in Chinese rural settings. Population-based tumor registration data collected by us in urban Shijiazhuang city (available for 2,374,827 people in 2012) and in rural Shexian County (available for 408,995 people since 2000) were used for urban rural comparison of age standardized incidence rate (ASIR) of westernization-related cancers in 2012, and the trend of biennial ASIR of these cancers for 2000-2015 in Shexian County was examined following a decade of rapid socioeconomic development and urbanization. From 1988-2015, the Gross Domestic Product per Capita (GDP) in rural Shexian County increased from 860 to 3000 US$, and urbanization rate from 22.4% to 54.8%. The biennial ASIRs of lung, colorectal, gallbladder cancer and leukemia in both sexes, and that of breast, ovary, thyroid, and kidney cancer in women increased significantly from 2000 - 2015. The increase from 2000-2001 to 2014-2015 in man and women for lung cancer was from 15.9 to 34.7 per 105 (P = 0.05) and 9.6 to 16.7 (P = 0.00), for colorectal cancer from 6.6 to 15.9 (P = 0.00) and 4.0 to 11.7 (P = 0.00), for gallbladder cancer from 0.1 to 2.4 (P = 0.00) and 0.3 to 2.7 (P = 0.00), for leukemia from 2.8 to 7.7 (P = 0.00) and 2.3 to 6.2 (P = 0.00);and in women for cancer of breast from 2.8 to 17.3 (P = 0.00), kidney from 0.2 to 2.4 (P = 0.00), ovary from 0.2 to 4.3 (P = 0.00), and thyroid from 0.2 to 4.2 (P = 0.00). Notwithstanding these increases, their ASIRs in 2012 in Shexian County were still significantly lower than that in Shijiazhuang city. Westernization-related cancer is increasing rapidly in rural China. Comprehensive measures are needed to strengthen prevention to ensure sustainable development.

Exploring the nonlinear piezoresistive effect of 4HSiC and developing MEMS pressure sensors for extreme environments

Microelectromechanical system(MEMS)pressure sensors based on silicon are widely used and offer the benefits of miniaturization and high precision.However,they cannot easily withstand high temperatures exceeding 150 ℃ because of intrinsic material limits.Herein,we proposed and executed a systematic and full-process study of Sic-based MEMS pressure sensors that operate stably from-50 to 300 ℃.First,to explore the nonlinear piezoresistive effect,the temperature coefficient of resistance(TCR)values of 4H-SiC piezoresistors were obtained from-50 to 500 ℃.A conductivity variation model based on scattering theory was established to reveal the nonlinear variation mechanism.Then,a piezoresistive pressure sensor based on 4H-SiC was designed and fabricated.The sensor shows good output sensitivity(3.38 mVN/MPa),accuracy(0.56%FS)and low temperature coefficient of sensitivity(TCS)(-0.067%FS/℃)in the range of-50 to 300 ℃.In addition,the survivability of the sensor chip in extreme environments was demonstrated by its anti-corrosion capability in H_(2)SO_(4) and NaOH solutions and its radiation tolerance under 5 W X-rays.Accordingly,the sensor developed in this work has high potential to measure pressure in high-temperature and extreme environments such as are faced in geothermal energy extraction,deep well dilling,aeroengines and gas turbines.