Dolomites occur extensively in the lower Cretaceous along syn-sedimentary fault zones of the Baiyinchagan Sag, westernmost Erlian Basin, within a predominantly fluvial-lacustrine sedimentary sequence. Four types of dolomite are identified, associated with hydrothermal minerals such as natrolite, analcime and Fe-bearing magnesite. The finely-crystalline dolomites consist of anhedral to subhedral crystals (2 to 10 μm), evenly commixed with terrigenous sediments that occur either as matrix supporting grains (Fd1) or as massive argillaceous dolostone (Fd2). Medium-crystalline (Md) dolomites are composed of subhedral to euhedral crystals aggregates (50 to 250 μm) and occur in syn-sedimentary deformation laminae/bands. Coarse-crystalline (Cd) dolomites consist of non-planar crystals (mean size >1 mm), and occur as fracture infills crosscutting the other dolomite types. Fd1, Md and Cd dolomites have similar values of δ 18 O (−20.5 to −11.0 ‰ Vienna PeeDee Belemnite) and δ 13 C (+1.4 to +4.5 ‰ Vienna PeeDee Belemnite), but Fd2 dolomites are isotopically distinct (δ 18 O −8.5 to −2.3‰ Vienna PeeDee Belemnite; δ 13 C +1.4‰ to +8.6‰ Vienna PeeDee Belemnite). Samples define three groups which differ in light rare-earth elements vs. high rare-earth elements enrichment/depletion and significance of Tb, Yb and Dy anomalies. Md dolomites have signatures that indicate formation from brines at very high temperature, with salinities of 11.8 to 23.2 eq. wt. % NaCl and T h values of 167 to 283°C. The calculated temperatures of Fd1 and Cd dolomites extend to slightly lower values (141 to 282°C), while Fd2 dolomites are distinctly cooler (81 to 124°C). These results suggest that the dolomites formed from hydrothermal fluid during and/or penecontemporaneous with sediment deposition. Faults and fractures bounding the basin were important conduits through which high-temperature Mg-rich fluids discharged, driven by an abnormally high heat flux associated with local volcanism. It is thought that differing amounts of cooling and degassing of these hydrothermal fluids, and of mixing with lake waters, facilitated the precipitation of dolomite and associated minerals, and resulted in the petrographic and geochemical differences between the dolomites.

Activity of polymeric carbon nitride (PCN), a promising photocatalyst for industrial application, is restricted seriously by low crystallinity. Herein, a soft-template induction strategy was proposed to synthesize PCN with highly...

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As a vital power propulsion device, gas turbines have been widely applied in aircraft. However, fly ash is easily ingested by turbine engines, causing blade abrasion or even film hole blockage. In this study, a three-dimensional turbine cascade model is conducted to analyze particle trajectories at the blade leading edge, under a film-cooled protection. A deposition mechanism, based on the particle sticking model and the particle detachment model, was numerically investigated in this research. Additionally, the invasion efficiency of the AGTB-B1 turbine blade cascade was investigated for the first time. The results indicate that the majority of the impact region is located at the leading edge and on the pressure side. In addition, small particles (1 m and 5 m) hardly impact the blade’s surface, and most of the impacted particles are captured by the blade. With particle size increasing, the impact efficiency increases rapidly, and this value exceeds 400% when the particle size is 50 m. Invasion efficiencies of small particles (1 m and 5 m) are almost zero, and the invasion efficiency approaches 12% when the particle size is 50 m.