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A passive and wireless sensor based on frequency selective surface (FSS) is presented for high-temperature applications. The sensor consists of a bent square loop array deposited in an alumina dielectric substrate. By inserting four symmetrical slots in the square loop structure, the dimension of the FSS unit cell is as compact as $0.13 \lambda _{{0}}$. The results show that the resonant frequency of the sensor decreases from 13.96 to 13.172 GHz with an average sensitivity of 0.81 MHz/°C when the temperature rises from 25 to 1000 °C. It was found that the resonant frequency shift is mainly attributed to the variations in permittivity of the substrate material. The sensor has a stable resonant frequency for both TE and TM polarizations under incident angles with a range of 0°–30°. The proposed sensor, which has the advantages of miniaturization, low profile, high sensitivity, and excellent angular stability, can be potentially applied in various harsh environments. [ABSTRACT FROM AUTHOR]

While various magnetic sensors have been developed over the years, the capability of passive wireless magnetic field detection is still lacking. Magnetic surface acoustic wave (MSAW) devices, combining magnetostrictive with piezoelectric materials, may be one of the candidates for wireless magnetic field sensing. This work proposes a novel microelectromechanical system (MEMS) MSAW resonator based on the AlN/Si/(Fe90Co10)78Si12B10 structure. The frequency responses of the resonator were measured when applying a dc magnetic field along the magnetic easy and hard axes. The results indicate that the resonator has higher magnetic sensitivity along the hard axis, with a maximum magnetic sensitivity of 11 kHz/Oe. When performing a magnetic field loop measurement for the hard axis, the resonator’s quality factor and resonance frequency showed almost the same variation tendency against the magnetic field. Moreover, the quality factor can attain about 3700 at the position of maximum magnetic sensitivity, which could simultaneously meet the needs of wireless interrogation and high sensitivity. Our work reveals that such an MEMS MSAW resonator has clear potential in the realization of wireless magnetic field sensors with miniaturization, low power, and high complementary metal–oxide–semiconductor (CMOS) compatibility for the future development of the Internet of Things (IoT). [ABSTRACT FROM AUTHOR]

A convenient, safe, and effective synthetic protocol for the synthesis of chiral β-homoglutamic acid was described. The strategy started from 3-cyclohexenecarboxylic acid, followed by three steps classic reaction including Curtius Rearrangement, oxidative cleavage of alkene, and debenzylation by catalytic hydrogenation. The chiral β-homoglutamic acid was prepared with a high yield and high enantiomeric excess. [ABSTRACT FROM AUTHOR]

Although supertetrahedral Tn sulfide clusters (n=2–6) have been extensively explored, the synthesis of Tn selenide clusters with n>4 has not been achieved thus far. Reported here are ionic‐liquid (IL)‐assisted precursor route syntheses, characterizations, and the photocatalytic properties of six new M‐In‐Q (M=Cu or Cd; Q=Se or Se/S) chalcogenide compounds, namely [Bmmim]12Cu5In30Q52Cl3(Im) (Q=Se (T5‐1), Se48.5S3.5 (T5‐2); Bmmim=1‐butyl‐2,3‐dimethylimidazolium, Im=imidazole), [Bmmim]11Cd6In28Q52Cl3(MIm) (Q=Se (T5‐3), Se28.5S23.5 (T5‐4), Se16S36 (T5‐5); MIm=1‐methylimidazole), and [Bmmim]9Cd6In28Se8S44Cl(MIm)3 (T5‐6). The cluster compounds T5‐1 and T5‐3 represent the largest molecular supertetrahedral Tn selenide clusters to date. Under visible‐light illumination, the Cu‐In‐Q compounds showed photocatalytic activity towards the decomposition of crystal violet, whereas the Cd‐In‐Q compounds exhibited good photocatalytic H2 evolution activity. Interestingly, the experimental results show that the photocatalytic performances of the selenide/sulfide solid solutions were significantly better than those of their selenide analogues, for example, the degradation time of the organic dye with T5‐2 was much shorter than that with T5‐1, whereas the photocatalytic H2 evolution efficiencies with T5‐3–T5‐6 improved significantly with increasing sulfur content. This work highlights the significance of IL‐assisted precursor route synthesis and the tuning of photocatalytic properties through the formation of solid solutions. [ABSTRACT FROM AUTHOR]

A novel NHC–Pd complex of 1,3‐bis (4‐ethoxycarbonylphenyl) imidazolium chloride has been synthesized and characterized by 1H NMR, 13C NMR, IR and X‐ray single‐crystal diffraction studies. TG analysis shows that the NHC‐Pd complex is stable under 208 °C. The catalytic activities have been explored for the synthesis of axially chiral N‐(2′‐methoxy‐1,1′‐binaphthalen‐2‐yl) benzophenone hydrazone. The result indicates that the novel NHC‐Pd complex can achieve better catalytic activity than the Pd‐phosphine catalysts in the synthesis of axially chiral N‐(2′‐methoxy‐1,1′‐binaphthalen‐2‐yl) benzophenone hydrazone. [ABSTRACT FROM AUTHOR]

For a better insight into the spectroscopic properties of [2.2]paracyclophane in fluorescent probes, a novel rhodamine-based chemodosimeter bearing [2.2]paracyclophane 4a has been designed and synthesized. The probe 4a exhibits a highly selective and sensitive response to Hg 2+ over other transition metal ions in aqueous solution. Its detection limit is determined to be 77 nM. The significant changes in the fluorescence color could be used for the naked-eye detection. Furthermore, the probe 4a shows good membrane permeability and can be applied to detect intracellular Hg 2+ in human lung adenocarcinoma cells (A549 cells). The crystal structure and spectral properties of its congener 4b that contains one 12-bromo [2.2]paracyclophane group and rhodamine moiety are also investigated for a comparison. [ABSTRACT FROM AUTHOR]