Paleozoic Multi-Stage Magmatic Events Related to Proto-Tethys and Paleo-Tethys Evolution:Insights from Intrusive Rocks in the Eastern Altyn Orogen,NW China

Abundant mafic-felsic intrusions distributed in the Altyn Orogen record orogenic histories related to Proto-Tethys and Paleo-Tethys evolution.Zircon U-Pb dating of the intrusive rocks in the eastern Altyn Orogen identifies at least three major tectono-magmatic episodes,yielding ages of∼426,∼376–373 and∼269–254 Ma.The first two emplacement episodes correspond to the post-collisional magmatism in the Altyn Orogen.The∼426 Ma granitoids possess adakitic characteristics coupled with enriched isotopes,suggesting that they originated from partial melting of thickened lower continental crust induced by upwelling asthenospheric mantle after slab break-off of the South Altyn Ocean Plate.Next,the∼376–373 Ma mafic-intermediate rocks and coeval granitoids represent a large thermal event that involved mantle melting with induced new juvenile lower continental crust melting in a post-collisional extensional setting.Finally,the∼254 Ma diabase dykes intruded into the∼269 Ma granitoids,which were related to the widespread Late Paleozoic magmatism resulting from Paleo-Tethys Ocean subduction.Post-collisional magmatism in the Altyn Orogen significantly enhances understanding of the tectono-magmatic evolution in the northern Tibetan Plateau.The penetrative influence of Paleo-Tethys Ocean subduction was more extensive than previously thought.

Boost industrial energy efficiency,Leading the way for industrial development

Recently,the Industrial Energy Efficiency Conference 2023 was held at Beijing West Suburb Hotel(see the figure).Zhi Hui,the secretary-general of the China Association of Industrial Energy Saving and Clean Production,pointed out at the conference that as China enters a new stage of high-quality development,industrial energy saving and efficiency improvement needs to shift to low-carbon energy,systematic whole-process energy conservation,and refined management.

A breakthrough of researching reservoir adsorption gas and its significance

GC-C-MS on linear isotope analysis equipment makes it possible to measure the hydrocarbon gases at the level of 10 -3-10 -2 μL- By applying this technique the carbon isotopes of C1-C3 of the adsorbed gas from the Triassic oil sand bed of the Aican-l Well in the Turpan-Hami basin were analysed. The δ13C values of C1-C3, are -55.1‰, -38.6‰ and -35.0‰ respectively. In terms of geochemical characteristics of natural gases and crude oils, in combination with basinal geological backgrounds, it is considered that the reservoir adsorbed gas was formed by crude-oil biodegradation, absorbed by reservoir rocks and its oil-gas source is related with the Permain (perhaps including the Carboniferous). The adsorbed gas is obviously different from the Jurassic coal-generated oil and gas.

Dispersion engineering and measurement in crystalline microresonators using a fiber ring etalon

Dispersion engineering and measurement are significant for nonlinear photonic applications using whispering gallery mode microresonators.Specifically,the Kerr microresonator frequency comb as an important example has attracted a great amount of interest in research fields due to the potential capability of full integration on a chip.A simple and cost-efficient way for dispersion measurements is thereby in high demand for designing such a microcomb device.Here,we report a dispersion measurement approach using a fiber ring etalon reference.The free spectral range of the etalon is first measured through sideband modulation,and the dispersion of the etalon is inferred by binary function fitting during the dispersion measurement.This method is demonstrated on two MgF_(2) disk resonators.Experimental results show good agreement with numerical simulations using the finite element method.Dispersion engineering on such resonators is also numerically investigated.