Seismic resolution enhancement in shale-oil reservoirs

We developed a case study of seismic resolution enhancement for shale-oil reservoirs in the Q Depression, China, featured by rhythmic bedding. We proposed an innovative methodology for the resolution enhancement, a full-band extension method, and implemented this method in three consecutive steps: wavelet extraction, filter construction and data filtering. First, we extracted a constant-phase wavelet from the entire seismic data set. Then, we constructed the full-band extension filter in the frequency domain using the least-squares inversion method. Finally, we applied the band extension filter to the entire seismic data set. We demonstrated that this full-band extension method, with a stretched frequency band from 7-70 Hz to 2-90 Hz, may significantly enhance the 3D seismic resolution and distinguish reflection events of the rhythmite groups in shale-oil reservoirs

Anomalous microwave response of high-temperature superconducting thin-film microstrip resonator in weak dc magnetic fields

We have studied an anomalous microwave (mw) response of superconducting YBa_{2}Cu_{3}O_{7-delta} (YBCO) microstrip resonators in the presence of a weak dc magnetic field, H_{dc}. The surface resistance (R_{s}) and reactance (X_{s}) show a correlated non-monotonic behaviour as a function of H_{dc}. R_{s} and X_{s} were found to initially decrease with elevated H_{dc} and then increase after H_{dc} reaches a crossover field, H_{c}, which is independent of the amplitude and frequency of the input mw signal within the measurements. The frequency dependence of R_{s} is almost linear at fixed H_{dc} with different magnitudes (H_{c}). The impedance plane analysis demonstrates that r_{H}, which is defined as the ratio of the change in R_{s}(H_{dc}) and that in X_{s}(H_{dc}), is about 0.6 at H_{dc}<H_{c} and 0.1 at H_{dc}>H_{c}. The H_{dc} dependence of the surface impedance is qualitatively independent of the orientation of H_{dc}.Comment: REVTex 3.1, 5 pages, 6 EPS figures, submitted to Physica

Multimetallic Oxynitrides Nanoparticles for a New Generation of Photocatalysts

A versatile synthetic strategy for the preparation of multimetallic oxynitrides has been designed and here exemplarily discussed considering the preparation of nanoscaled zinc\u2013gallium oxynitrides and zinc\u2013gallium\u2013indium oxynitrides, two important photocatalysts of new generation, which proved to be active in key energy related processes from pollutant decomposition to overall water splitting. The synthesis presented here allows the preparation of small nanoparticles (less than 20 nm in average diameter), well-defined in size and shape, yet highly crystalline and with the highest surface area reported so far (up to 80 m2 g 121). X-ray diffraction studies show that the final material is not a mixture of single oxides but a distinctive compound. The photocatalytic properties of the oxynitrides have been tested towards the decomposition of an organic dye (as a model reaction for the decomposition of air pollutants), showing better photocatalytic performances than the corresponding pure phases (reaction constant 0.22 h 121), whereas almost no reaction was observed in absence of catalyst or in the dark. The photocatalysts have been also tested for H2 evolution (semi-reaction of the water splitting process) with results comparable to the best literature values but leaving room for further improvement

Prevalence and sociodemographic and lifestyle determinants of anemia during pregnancy: a cross-sectional study of pregnant women in China

Published: 13 September 2016Objective: This study aimed to assess the differences regarding anemia among pregnant women with diverse characteristics and lifestyle factors. Methods: A cross-sectional study of pregnant women was conducted between June and August 2015 in 16 hospitals in five provinces of Mainland China. Self-reported doctor-diagnosed anemia was used in the study. Results: We included 2345 pregnant women. Of the participants, 1755 (74.8%) were pregnant women of first pregnancy (PWFP) and 590 (25.2%) were second pregnancy (PWSP). The mean age of the participants was 28.1 years (SD 4.1). Overall, the prevalence of anemia was 12.7% (13.4% and 10.7% among PWFP and PWSP, respectively). The prevalence for not eating breakfast was 11.0%. Compared with PWFP, PWSP was inversely associated with the risk of anemia (odds ratio (OR) 0.66, 95% CI 0.48-0.91). Compared with those being registered in a low ranking hospital, pregnant women who were admitted to a high (OR 0.40, 95% CI 0.28-0.57) or a medium ranking hospital (OR 0.58, 95% CI 0.37-0.92) were inversely associated with the risk of anemia. Compared with women of low income (<¥4,500), those with high income were less likely to have anemia (OR 0.68, 95% CI 0.50-0.94). Compared with women with non-manual jobs, women with manual jobs (OR 1.70, 95% CI 1.17-2.45) and unemployed women (OR 1.42, 95% CI 1.04-1.93) were associated with a greater likelihood of suffering from anemia. Conclusions: Pregnant women not eating breakfast are of concern. Anemia is highly prevalent among pregnant women in China. Lower socio-economic status, manual jobs, PWFP, and those who attend a lower quality hospital have a greater likelihood of suffering from anemia. Tailored interventions are needed to address these issues.Xianglong Xu, Sheng Liu, Yunshuang Rao, Zumin Shi, LianLian Wang, Manoj Sharma and Yong Zha

Combined regenerated fibre Bragg gratings and Fabry-Perot etalons for dual strain and temperature sensing

© 2015 SPIE. A highly integrated fibre-optic sensor with regenerated fibre Bragg grating (RFBG) and a micro Fabry-Pérot (MFP) is proposed and demonstrated for simultaneous measurement of temperature and strain under high temperature (> 600°C). The MFP is fabricated by using a 157 nm fluorine gas (F2) laser to micromachine the core of a standard optical fibre. The RFBG is fabricated by regenerating a seed grating written over the Fabry-Pérot. Since the MFP and RFBG have different sensitivity coefficients, their combination can be used to realise simultaneous measurement of temperature and strain. It is believed that such a high-temperature strain sensor could find important applications in many areas where simultaneous measurement of temperature and strain under high temperature is required