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Terahertz (THz) metamaterial sensor is a newly-developing interdisciplinary technology, which combines the essential characteristics of THz spectroscopy and metamaterials, to obtain better sensitivity for trace detection of the different target analytes. Toroidal dipole resonances show great sensing potential due to their suppression of the radiative loss channel. Here, we found a high-quality planar toroidal dipole resonance in the breaking Chinese Taichi-like ring and then designed a novel polarization-independent terahertz toroidal sensor by combining four Taichi-like rings into a cycle unit. The sensor shows high-sensitivity sensing characteristics for the ultrathin analyte and refractive index. The optimized sensitivity of pure analytes under 4 μm coating thickness can numerically reach 258 GHz/RIU in the corresponding ∼1.345 THz frequency domain, which is much higher than that of previously reported sensors. We further fabricated experimentally the sensor and demonstrated its fascinating polarization-independent characteristics. Finally, it was successfully applied to the low-concentration detection (ranging from 0.0001 mg/mL to 10 mg/mL) of Aβ protein associated with Alzheimer’s disease. Our high-sensitivity polarization-independent THz toroidal dipole sensor would give access to rich applications in label-free biosensing.

Zircon U–Pb dating and whole‐rock geochemical analysis have been studied on the Late Jurassic volcanic rocks in the Hailisen area, Northeastern China, with the aim of constraining the tectonic evolution of the central‐southern Great Xing'an Range during the Late Jurassic. The volcanic rocks mainly consist of andesite from the Tamulangou Formation, and rhyolite and minor dacite from the Manketouebo Formation. The results of inductively coupled plasma‐mass spectrometry Zircon U–Pb dating for two andesites and one dacite indicate that they formed in the Late Jurassic (161–150 Ma). The mafic rocks are characteristic of low TiO2 (1.01–1.04 wt.%) and P2O5 (0.23–0.31 wt.%) contents, and high Al2O3 (17.19–20.18 wt.%) and CaO (6.69–7.45 wt.%) contents, and belong to the low‐K tholeiitic series. These mafic rocks are also characterized by moderately enriched light rare earth element (LREE) patterns and high abundances of Th, U, Zr, and Hf but negative Nb, Ta, and Ti anomalies. The felsic rocks are enriched in alkalis, Th, U, and LREEs; depleted in Ba, Sr, Nb, Ta, and Ti; and exhibit moderately LREE‐enriched patterns. These features indicate that the mafic volcanic rocks were likely formed by the partial melting of a lithospheric mantle that was metasomatized by subduction‐derived components, but the felsic rocks could derived by partial melting of a crustal source. The Tamulangou and Manketouebo formations have compositions of typical bimodal volcanism, an extensional environment, similar to a post‐orogenic setting, which might be related to the closure of Mongol–Okhotsk Ocean. [ABSTRACT FROM AUTHOR]

Zircon U–Pb dating and whole-rock geochemical analysis have been performed on Late Jurassic – Early Cretaceous intrusive rocks of the Ulanhot area, NE China, with the aim of constraining the tectonic evolution of the central and southern Da Xingan Range. Zircon U–Pb dating indicates that Late Jurassic – Early Cretaceous magmatic events experienced four stages at: c. 155 Ma; c. 144 Ma; 135–130 Ma; and c. 126 Ma. The c. 155 Ma magmatic event consists of quartz diorite and granite-porphyryp with the geochemical characteristic of high Sr and Sr/Y or high A/CNK (1.38), implying the primary magma was derived from partial melting of a thickened lower crust which induced the closure of the Mongol–Okhotsk Ocean. The c. 144 Ma magmatic event consists of quartz monzodiorite with the geochemical characteristics of alkaline series, and indicates the delamination of a thickened crust. The 135–130 Ma magmatic event consists of syenogranite and granite-porphyry with characteristics of both I-type and A-type granites, which induced both the subduction of the Palaeo-Pacific oceanic plate and the post-orogenic extension of the Mongol–Okhotsk Orogenic Belt. The c. 126 Ma magmatic event consisted of highly fractionated I-type biotite granite and alkaline series gabbro, marking the end of the Mongol–Okhotsk Orogen, and implying that the study area was controlled by the circum-Pacific tectonic system during this stage. [ABSTRACT FROM AUTHOR]

The Taolaituo porphyry-type molybdenum deposit is located in the eastern Inner Mongolia Autonomous Region in China. The mineralization occurs mainly as veins, lenses and layers within the host porphyry. To better understand the link between the mineralization and the host igneous rocks, we studied samples from the underground workings and report new SHRIMP II zircon U-Pb and Re-Os molybdenite ages, and geochemical data from both the molybdenites and the porphyry granites. Five molybdenite samples yield a Re-Os isochron weighted mean age of 133.0 ± 0.82 Ma, whereas the porphyry granitoids samples yield crystallization ages of 133 ± 1 Ma and 130.4 ± 1.3 Ma. The U-Pb and Re-Os ages are similar, suggesting that the mineralization is genetically related to the Early Cretaceous porphyry emplacement. Re contents of the molybdenites range from 21.74 to 42.45 ppm, with an average of 32.69 ppm, whereas δ34S values vary between 3.7‰ and 4.2‰, which is typical of mantle sulphur. The 206Pb/204Pb, 207Pb/ 204Pb and 208Pb/204Pb vary in the ranges of 18.276-18.385, 15.566-15.580 and 38.321-38.382, respectively. The Taolaituo Early Cretaceous granitoids are A-type granites. These observations indicate that the molybdenites and the porphyry granites were derived from a mixed source involving young accretionary materials and enriched subcontinental lithospheric mantle. A synthesis of geochronological and geological data reveals that porphyry emplacement and Mo mineralization in the Taolaituo deposit occurred contemporaneously with the Early Cretaceous tectonothermal events associated with lithospheric thinning, which was caused by delamination and subsequent upwelling of the asthenosphere associated with intra-continental extension in northeast China. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Yili porphyry-type molybdenum deposit is located in the Northeastern Inner Mongolia Autonomous Region in China. Mineralization occurs mainly as veins, lenses, and layers within the host porphyry. In order to better understand the link between mineralization and host igneous rocks, we studied samples from underground workings. We report new Sensitive High Resolution Ion Microprobe II (SHRIMP II) zircon U–Pb and Re–Os molybdenite ages and geochemical data from the Yili granitoids. Five molybdenite samples yield a Re–Os isochron weighted mean age of 131.1 ± 3.4 Ma, while two Early Cretaceous adakitic porphyry granite samples yielded crystallization ages of 128.1 ± 1.6 Ma and 129.0 ± 3.5 Ma. The U–Pb and Re–Os ages are analytically indistinguishable, suggesting that mineralization was genetically related to Early Cretaceous magmatism in northeastern China. δ34SV-CDTvalues of the sulphide vary from 0.3‰ to 3.8‰. We obtained two weighted mean U–Pb zircon ages of 287.7 ± 1.8 Ma for early Permian fine-grained granite and 349.8 ± 2.3 Ma for Early Carboniferous monzogranite in Yili area, respectively. A synthesis of geochronological and geological data reveals that porphyry emplacement and Mo mineralization in the Yili deposit occurred at the same time as Early Cretaceous lithospheric thinning, which was caused by the delamination and subsequent upwelling of the asthenosphere under the intra-continental extension in northeastern China. [ABSTRACT FROM AUTHOR]

A new method to improve the integration level of an on-chip diffractive optical neural network (DONN) is proposed based on a standard silicon-on-insulator (SOI) platform. The metaline, which represents a hidden layer in the integrated on-chip DONN, is composed of subwavelength silica slots, providing a large computation capacity. However, the physical propagation process of light in the subwavelength metalinses generally requires an approximate characterization using slot groups and extra length between adjacent layers, which limits further improvements of the integration of on-chip DONN. In this work, a deep mapping regression model (DMRM) is proposed to characterize the process of light propagation in the metalines. This method improves the integration level of on-chip DONN to over 60,000 and elimnates the need for approximate conditions. Based on this theory, a compact-DONN (C-DONN) is exploited and benchmarked on the Iris plants dataset to verify the performance, yielding a testing accuracy of 93.3%. This method provides a potential solution for future large-scale on-chip integration.