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Graphical abstract Highlights • Fe 3 O 4 @PS-TMG was synthesized by immobilizing TMG onto the shell of nanohybrids. • The loading of TMG as well as surface property of catalyst can be well regulated. • The MPIC can stabilize soybean oil-in-methanol Pickering emulsion. • The MPIC exhibited higher catalytic activity for transesterification. Abstract A novel magnetic Pickering interfacial catalyst (MPIC) was developed and used for highly effective and clean production of biodiesel. The catalyst was synthesized by immobilization of 1,1,3,3-tetramethylguanidine (TMG) onto the shell of Fe 3 O 4 @Chloromethyl PS nanohybrids. The resultant Fe 3 O 4 @PS-TMG was measured by transmission electron microscope (TEM), dynamic lighting scattering (DLS), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA), thermogravimetric analysis (TG), contact angles (CA). The results showed that surface property and TMG loading of catalyst can be finely regulated via adjusting the feeding of TMG. Fe 3 O 4 @PS-TMG with amphiphilic surface can stabilize soybean oil-in-methanol Pickering emulsion, which would offer large interfacial area and surface enrichment of reactants, leading to a significant enhancement of such liquid-liquid (L-L) biphasic reaction with high mass transfer resistance. Furthermore, the MPIC can be facile separated from the mixture of reaction by magnet, and showed excellent stability over 5 recycles. [ABSTRACT FROM AUTHOR]

This paper analyzes different noise components in MEMS gyroscope silicon structure, including mechanical–thermal noise (MTN), electronic-thermal noise (ETN), flicker noise (FN) and Coriolis signal in-phase noise (IPN). The structure equivalent electronic model is established, and the improved differential interface is proposed based on weak signal detection technology, after that, the noise components in silicon structure are introduced and analyzed in sense open loop. The quadrature error (QE) signal automatically cancellation loop is proposed, and the results of the experiment indicate that the equivalent angular rates of QE and IPN are 46°/s and 4.55°/s respectively. The interfaces contrast experiments show that the DC noise and the useful signal amplitudes of differential and single-side detection interfaces are −49.8 dBmV, −16.8 dBmV and −39.8 dBmV (−42.1 dBmV), −22.1 dBmV (−22.2 dBmV), which confirms the differential interface has better SNR. The carrier experiments also illustrate that higher carrier frequency (from 500 kHz to 10 MHz) can restrain DC noise (from −19.8 dBmV to −54.2 dBmV) better, which demonstrate the FN is the dominant noise component of the silicon structure under normal temperature. The temperature experiments show the DC noise enhances from −48.5 dBmV to −14.6 dBmV over the range 20 °C to 60°C while the useful signal amplitude remains around -16.6dBmV, and this phenomenon indicates the MTN and ETN become the dominant structure noise components gradually with temperature rising. [ABSTRACT FROM AUTHOR]

• The mechanism of nonreciprocal errors under the magnetic field-variable temperature field is proposed. • Based on dual-polarization interferometric fiber optic gyroscope (IFOG). • The nonreciprocal errors under the magnetic field, variable temperature field and magnetic field-variable temperature field are compared. A dual-polarization fiber optic gyroscope system is built to systematically analyze the nonreciprocal errors of the system under the magnetic field-variable temperature field. Under the magnetic field-variable temperature field, the nonreciprocal errors are caused by magnetic-thermal coupling birefringence nonreciprocal error, linear birefringence nonreciprocal error and Shupe effect error. The nonreciprocal errors of dual-polarization fiber optic gyroscope system are related to temperature and temperature gradient. In X and Y polarization states, the signs of magnetic-thermal coupling birefringence nonreciprocal error and linear birefringence nonreciprocal error are opposite, and these two errors can be suppressed in the dual-polarization system. But the Shupe effect errors are the same in X and Y polarization states, which can not be suppressed in the dual-polarization system. The experimental results are consistent with the theoretical analysis, which verifies the correctness of the nonreciprocal error model under the magnetic field-variable temperature field. The research results provide a theoretical and experimental basis for the study of the environmental adaptability of the fiber optic gyroscope and other common-path fiber sensing systems based on dual-polarization. [ABSTRACT FROM AUTHOR]