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The East Kunlun Orogenic Belt (E-KOB) in the northern Tibet Plateau has undergone a long multi-stage history of drifting, accretion, and collision of the Proto- and Palaeo-Tethyan oceans. It has been addressed a trench-arc-back-arc basin system of the Proto-Tethys in the E-KOB, and the tectonic history of this major ocean has been well constrained by previous studies. However, the evolution of the back-arc basin still remains unclear. In this study, the Yugusayi monzodiorite, quartz-bearing syenite, and gradually contacted skarn rocks characterized by garnet megacrysts, in the North Qimantagh Belt were investigated. To reveal the tectonic setting and skarnization mechanism, geochemical and geochronological studies were conducted on the intrusions and garnet skarn, and the elemental compositions of the garnet megacrysts were also analysed. These monzodioritic rocks have high MgO (6.87–8.31 wt.%), Sr and La contents, low Y and Yb contents, and relatively high La/Yb (31–55) and Sr/Y (41–51) ratios, resembling to high-Mg adakites. They display right-sloping chondrite-normalized REE patterns, enriched in LILEs, and depleted in Ti with significant Nb-Ta troughs, which are similar to those of continental arc rocks. Zircons from monzodiorite and skarn samples have contemporaneous U-Pb ages of 459 ± 3 Ma and 454 ± 4 Ma with εHf(t) values of − 8.53 to − 4.64 and − 7.7 to + 12.8, respectively. In addition, the chemical zoning garnet megacrysts are composed mainly of grossular and andraditic grossular, and are characterized by spoon-shaped REE patterns. Based on our new data and the regional geology, it can be concluded that the Yugusayi intrusive rocks formed in a subduction-related tectonic setting and resulted in the skarnization. These data not only provide key constraints on the initial subduction of the Qimantagh back-arc basin's oceanic crust, but also offer a unique opportunity to explore the Caledonian skarnization in the Qimantagh Belt. [ABSTRACT FROM AUTHOR]

Although near‐infrared (NIR) light‐based photothermal therapies have shown therapeutic potential for infected wounds, the attenuation of NIR light intensity in tissue has severely limited the usage in deep bacterial infections. Herein, magneto‐thermal responsive bilayer microneedles (Fe‐Se‐HA MNs) consisting of functionalized hyaluronic acid (HA), ferro‐ferric oxide (Fe3O4), and micelle‐protected selenium nanoparticles (SeNPs@LAS) are constructed to overcome this challenge based on a self‐designed disk‐shaped electromagnetic field device (Disk‐ZVS). The electromagnetic field generated by the Disk‐ZVS shows virtually no intensity attenuation in living tissue. Finite element simulations showed that the field intensity and electromagnetic loss are concentrated on the tips of Fe‐Se‐HA MNs. The MNs are able to puncture hard scabs, penetrate into bacterial biofilms, and perform effective magnetic‐thermal conversion for deep hyperthermia sterilization. Following, the Fe‐Se‐HA MNs can be gradually degraded by excessive hyaluronidase in diabetic wound to release SeNPs, which reduce reactive oxygen species (ROS) to regulate wound redox homeostasis. Meanwhile, the SeNPs are beneficial to angiogenesis, which facilitates blood vessel formation and promotes wound repair. Therefore, various functions can be achieved for the Fe‐Se‐HA MNs, such as magneto‐thermal disinfection, deep and non‐invasive tissue penetration, anti‐inflammation, and pro‐angiogenesis, which shows great potential as an adjunctive therapy for infected diabetic wounds. [ABSTRACT FROM AUTHOR]

The East Kunlun Orogenic Belt (E-KOB) documents successive subduction and accretion processes of the Paleo-Tethyan Ocean. However, the tectonic regime of the E-KOB at the late orogenic stage remains ambiguous. This study presents new results of whole-rock geochemistry and zircon U-Pb-Hf isotopes of the Xidatan pluton in the southern E-KOB. Detailed investigation reveals that the pluton is composed of quartz monzodiorite, host monzogranite, and igneous microgranular enclaves (IMEs). Zircon U-Pb dating results suggest that they are coeval magmatic rocks emplaced at ca. 206–203 Ma. Geochemical studies reveal that the quartz monzodiorite and IMEs share a common magma source, evidenced by consistent compositions of major elements, congruently enriched LREEs and LILEs, and consistently moderately depleted HFSEs and HREEs. Enriched to slightly juvenile zircon Hf isotopes (εHf(t) = −4.24 to +0.49) indicate that the primitive magmas of the quartz monzodiorite and IMEs involve the addition of mantle-derived magmas. The quartz monzodiorite and IMEs have identical ages, and consistent isotope features with the host monzogranite, together with the observation of ingestion of xenocrysts from host felsic rocks into the IMEs indicating that they were produced through the mixing of the mantle-derived mafic magmas and host felsic magmas. In contrast, The host monzogranite has moderately high SiO2 and Na2O+K2O, but low Fe2O3T and MgO contents. It shows crust-like trace element patterns such as strong enrichments in LREEs and LILEs, but remarkable depletions in HREEs. Along with enriched zircon Hf isotopes (εHf(t) = −3.51 to −0.25), the host monzogranite was most likely to have originated from partial melting of lower crustal mafic rocks induced by underplated mantle-derived magmas. Considering abundant Late Triassic igneous rocks across the E-KOB, these new data provide further evidence that the Late Triassic magmatism in the E-KOB may be related to the delamination of thickened orogenic root under an extensional setting. [ABSTRACT FROM AUTHOR]

In accordance with the requirements of unmanned robot driving power supply for power supply reliability, strong power output, and portability, this paper introduces a design scheme for unmanned robot driving power supply on the basis of a flyback converter, establishes the mathematical model of driving power supply (flyback converter), designs the transformer part of a flyback converter, and recommends a straightforward and efficient clamping circuit to enhance it. The controller of the flyback converter is designed in detail. Ultimately, the feasibility and effectiveness of the design method in the driving power supply of unmanned robots are demonstrated by simulation and experiments. [ABSTRACT FROM AUTHOR]

The evolution of the Tethys is one of the key issues in revealing the global ocean-continent transition tectonic process. The East Kunlun Orogenic Belt (E-KOB) in the northern Tibetan Plateau witnessed the subduction-accretion process of the Proto- and Palaeo-Tethyan Oceans formed a trench-arc-back arc basin system. Thus, this back arc basin is a window for exploring the tectonic evolution of the Tethys. In this study, the Adatan garnet amphibolites and the host paragneiss were investigated and used to constrain the evolution of the back arc basin. The mineralogical observations and microstructure of the garnet amphibolite suggest the successive formation of three mineral assemblages: a Hb + Pl + Ilm inclusion assemblage within garnet cores, a Grt + Pl + Hb + Bit + Phe matrix assemblage, and a retrograde assemblage of white-eye coronas around the garnet. The thermobarometric calculations suggest a clockwise P-T path with peak metamorphic conditions of 10.1–12.6 kbar and 715–830°C and a subsequent near-isothermal decompression process. The geochemistry indicates that the protolith of the garnet amphibolites was formed in a subduction-related tectonic setting with enriched mid-ocean ridge basalt (E-MORB) geochemical characteristics. U-Pb zircon dating reveals that the crystallization age of the garnet amphibolite's protolith is ca. 457–452 Ma. Based on field occurrences, the protolith of the amphibolite was probably mafic dikes that intruded into the paragneiss due to subduction of the back-arc basin. Both the garnet amphibolite and gneissic rocks experienced contemporaneous metamorphism at ca. 420–410 Ma, suggesting that a crustal thickening event occurred due to closure of the back-arc basin and arc-continent collision. Based on the above evidence and the results of previous studies, it can be concluded that the Qimantagh back arc basin involved opening, subduction, and closure tectonic processes at ca. 486 Ma, ca. 460 Ma and ca. 420–410 Ma, respectively. [ABSTRACT FROM AUTHOR]