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Mantle‐derived volatile degassing lacks quantitative evaluation in continental regions without active magmatism, such as the Tibetan Plateau. Ten new gas abundance and helium isotope data points combined with 286 hydrothermal volatile literature data points in India–Asia continental collision settings demonstrate widespread mantle‐derived volatiles across the thick (∼70 km) crust. The mantle‐derived 3He is best explained by direct mantle volatile input from subcontinental lithospheric mantle (1%–36.5%) or the asthenospheric wedge (1%–27.8%) instead of fossil residual magmatic fluids or Quaternary mantle‐derived melt intrusion into crustal depth. Mantle‐derived 3He is transported from the deep mantle to the surface at an upflow rate of 30–11,700 mm/year based on a newly developed steady‐state one‐dimensional flow model, corresponding to a mantle‐derived 3He flux of 17 to 1.5 × 107 atoms m−2 s−1 (81.7%–99.4% of the total 3He flux) and a mantle‐derived 4He flux from 2.0 × 106 to 1.8 × 1012 atoms m−2 s−1 (1.4%–36.5% of the total 4He flux). The mantle‐derived helium fluxes in the study area are comparable to those of other nonvolcanic hydrothermal systems in the tectonically active regions but lower than those of volcanic fields. The helium transit time ranges from 5.3 ka to 2.3 Ma, indicating that the spatial pattern of 3He/4He ratios in the India‐Asia continental collision settings can provide a snapshot of the state of the Indian mantle lithosphere between those revealed by potassic‐rich mafic rocks (25–8 Ma) and seismic methods (present). Key Points: 3He is derived directly from mantle depths instead of residual magmatic fluids or Quaternary mantle‐derived melt in the shallow crustThe vertical flow rate, flux and transit time of mantle‐derived 3He were systematically calculatedThe state of the Indian mantle lithosphere revealed by mantle‐derived 3He is between that revealed using petrologic and seismic methods [ABSTRACT FROM AUTHOR]

Elucidating brine origin and evolution is a fundamental but not easy task especially for coastal geothermal systems with possible marine constituents and multistage evolution, as subsequently physical, chemical and biological alteration processes may mask the original and early-stage signatures. Here chemical and isotopic characteristics of water (D and 18O) and dissolved constituents (13C, 14C, 11B and 87Sr/86Sr) have been utilized to investigate the source and multistage evolution of the Jimo coastal geothermal system in eastern China, with dramatic differences of geochemical characteristics observed within a 0.2 km2 area. Results show that geothermal water is derived from paleo-meteoric water and has undergone a 3-stages evolution that involves: (1) Dissolution of marine halite and potash salts in the deep reservoir; (2) Water-rock reactions especially cation exchange produces a Cl-Na-Ca type water as deep geothermal water upwells along the fault zone; (3) A minor (

A comparative study, in aspects of both wavelength dependence and fabrication tolerance, is carried out between silica-based phase shifters designed in two different regime, namely length difference regime and refractive index difference regime. Results show that in the wavelength range of 1500-1600 nm, phase shifter designed in refractive index difference regime has a working wavelength range 2.8~3.1 times wide as that designed in length difference regime; while in the aspect of fabrication tolerance, phase designed in length difference regime is advantageous, with respect to waveguide core dimension error, and waveguide core refractive index error as well.

Transition metal ion-doped pnictogen-chalcogen binary V2VI3 compounds presents excellent photocatalytic activity due to the sp-d exchange interactions between host and magnetic ions. In this work for the first investigation, multi-valence states of cobalt-doped Bi2S3 nanocomposite catalysts were hydrothermally synthesized, their morphology, structure, chemical valence states, optical, magnetic, photoelectric and photocatalytic properties were characterized through varies techniques such as Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Ultraviolet visible & photoluminescence spectra, Raman and FT-Infrared spectra, Vibration sample magnetometer, electron paramagnetic resonance spectra, and electrochemical impedance test. 15 nm-diameter well-dispersed nanorods were synthesized and the Co doping did not significantly increase the size of nanorods. The infrared and Raman spectra analysis indicate the Co entered the lattice and introduced strain and deformation on structure due to the difference of ionic radius and electronegativity of Co and Bi. X-ray photoelectron spectra display the co-existence of Co2+ and Co3+ inside Bi2S3 which give different contributions to optical bandgap, optical absorption and emission behaviors. Density functional theory modeling and calculation on the energy bandgap and electron excitation states were performed. The simulation is consistent with experimental results. All samples show typical ferromagnetism character with enhanced magnetization. The magnetic susceptibility versus temperature curves imply that Co-doped sample follow the Curie–Weiss law. The photocatalytic activity was greatly enhanced by the Co doping due to the active electron transition and charge transfers which were further verified by electron paramagnetic resonance spin trapping studies. The photoelectric performances were finally studied and the result explained the mechanism of photocatalytic improvement due to the increase of conductivity and photoelectric efficiency. BiCoS3 sample was proved to be effective photocatalyst for waste-water treatment. [ABSTRACT FROM AUTHOR]