A preparative technique for spiral thin-film transformer at GHz frequency band

This paper present a preparative technique for spiral thin-film transformer with ferrite magnetic core. RF magnetron sputtering is used to prepare ferrite thin film on SiO2 layer. Compatible problems of thin film with IC technology are observed by SEM. The problems are resolved through sputtering parameters modification and heating treatment addition. S-parameters are measured at 10 MHz-20 GHz. The result shows that The experience result shows, magnetic core thin-film transformer with 15:15 ratio-turn can obtain the maximal transmission efficiency 80.9% at 10 MHz-20 GHz, and the air core transformer can obtain the maximal transmission efficiency 55.4% at same frequency range. Ferrite thin film can improve the transmission efficiency evidently

Image-Based Dedicated Methods of Night Traffic Visibility Estimation

Traffic visibility is an essential reference for safe driving. Nighttime conditions add to the difficulty of estimating traffic visibility. To estimate the visibility in nighttime traffic images, we propose a Traffic Sensibility Visibility Estimation (TSVE) algorithm that combines laser transmission and image processing and needs no reference to the corresponding fog-free images and camera calibration. The information required is first obtained via the roadside equipment which collects environmental data and captures road images and then analyzed locally or remotely. The proposed analysis includes calculating the current atmospheric transmissivity with the laser atmospheric transmission theory and acquiring image features by using the cameras and the adjustable brightness target. Image analysis is performed using two image processing algorithms, namely, dark channel prior (DCP) and image brightness contrast. Finally, to improve the accuracy of visibility estimation, multiple nonlinear regression (MNLR) is performed on the various visibility indicators obtained by the two methods. Extensive on-site measurements analysis confirms the advantages of TSVE. Compared with other visibility estimation methods, such as the laser atmospheric transmission theory and image analysis method, TSVE significantly decreases the estimation errors

Microbial Diversity and Biochemical Analysis of Suanzhou: A Traditional Chinese Fermented Cereal Gruel

Suanzhou as a traditional Chinese gruel is fermented from proso millet and millet. The biochemical analysis showed Suanzhou had relatively high concentrations of lactic acid, acetic acid, and free amino acids. The metagenomics of Suanzhou were studied, with the analysis of the V4 region of 16S rRNA gene, the genera Lactobacillus and Acetobacter were found dominant with the average abundance of 58.2% and 24.4%, respectively; and with the analysis of the ITS1 region between 18S and 5.8S rRNA genes, 97.3% of the fungal community was found belonging to the genus Pichia and 2.7% belonging to 5 other genera. Moreover, the isolates recovered from 59 Suanzhou samples with various media were identified with the 16S rRNA or 18S rRNA gene analyses. L. fermentum (26.9%), L. pentosus (19.4%), L. casei (17.9%), and L. brevis (16.4%) were the four dominant Lactobacillus species; A. lovaniensis (38.1%), A. syzygii (16.7%), A. okinawensis (16.7%), and A. indonesiensis (11.9%) were the four dominant Acetobacter species; and Pichia kudriavzevii (55.8%) and Galactomyces geotrichum (23.1%) were the two dominant fungal species. Additionally, L. pentosus p28-c and L. casei h28-c1 were selected for the fermentations mimicking the natural process. Collectively, our data demonstrate that Suanzhou is a nutritional food high in free amino acids and organic acids. Diverse Lactobacillus, Acetobacter, and yeast species are identified as the dominant microorganisms in Suanzhou. The isolated strains can be further characterized and used as starters for the industrial production of Suanzhou safely

Two-channel ultrasonic water flowmeter based on time difference method

For the small and medium diameter mono ultrasonic flowmeter due to the small number of channels vulnerable to uneven flow field distribution, a dual-channel ultrasonic water flowmeter based on the time difference method is proposed. The hardware system of the flowmeter consists of STM32L431 low-power module, high-precision timing module TDC-GP22 and other components. According to the dual-channel pipe segment structure, the data fusion method based on Kalman filter algorithm is proposed to fuse the measurement data of the two channels and complete the filtering process, which improves the measurement accuracy of the flowmeter. The experimental test shows that the flowmeter measurement error is within 2.5%, and the Kalman fusion filtering algorithm can effectively improve the flowmeter measurement accuracy

Performance Enhancements of Femtosecond Fiber Amplifier by Pump Wavelength Optimization

We demonstrate an efficient scheme to accelerate the self-similar pulse evolution and reduce the intensity noise of a free-running femtosecond fiber amplifier based on the pump wavelength optimization. Experiments and simulations indicate the enhanced tolerances of the pulse self-similar amplification to the seed signal power and pump wavelength fluctuations, with the optimum 915 nm pump wavelength. ∼20% increase in the compressed pulse quality and ∼31% reduction in the amplifier root-mean-square (RMS) relative intensity noise (RIN) (1.5 kHz to 5 MHz) have been observed, even with a more than 4 times higher pump laser diode (LD) RIN than the case of 976 nm. ∼50 fs transform-limited pulses are generated with the ∼0.03% amplifier RMS RIN. The proposed scheme can lower the requirements of low-noise self-similar femtosecond fiber amplifiers on the power stability of the seed oscillator and the thermal control of the pump LD, thus denoting potentials for the various satellite-based high-precision applications of femtosecond laser in space

Overview of intelligent road sign system design

Intelligent signage system is an important tool to realize the rapid development of intelligent transportation and intelligent city. Traditional road signs can only use fixed words, symbols and colors to unilaterally transmit information to traffic participants, which cannot effectively control traffic flow and meet people ' s travel needs. The emergence of intelligent signs makes up for these defects. Firstly, the current situation of traditional road signs is reviewed. In view of the impact of intelligent signs on people ' s travel and future urban road development, the shortcomings of traditional signs and the development needs of intelligent signs are analyzed from different perspectives of information perception, information communication and low power consumption. The key technologies in intelligent signs are expounded. Finally, the future development is prospected and summarized

A 3D Free Vibration Analysis of the Horn-Gear System through Chebyshev–Ritz Method in Ultrasonic Gear Honing

Applying the ultrasonic machining in gear honing can improve honing speed, reduce cutting force, and avoid blocking. There are two problems leading to the decrease of calculation accuracy in the traditional nonresonant theory of the ultrasonic gear honing. One is that one-dimensional longitudinal vibration theory and two-dimensional theory cannot reflect the vibration characteristics of ultrasonic horn and gear comprehensively. And, the other one is that the difference of the analysis dimension between the two theories leads to mismatch of the coupling condition dimension between ultrasonic horn and gear. A free vibration analysis through Chebyshev–Ritz method based on three-dimensional elasticity theory was presented to analyze the eigenfrequencies of the horn-gear system in ultrasonic gear honing. In the method, the model of the horn-gear system was divided into four parts: a solid circular plate, an annular plate, a solid cylinder, and a cone with hole. The eigenvalue equations were derived by using displacement coupling condition between each part under completely free boundary condition. It was found that the eigenfrequencies were highly convergent through convergence study. The hammering method for a modal experiment was used to test the horn-gear systems’ eigenfrequencies. And, the finite element method was also applied to solve the eigenfrequencies. Through a comparative analysis of the frequencies obtained by these three methods, it showed that the results achieved by the Chebyshev–Ritz method were close to those obtained from the experiment and finite element method. Thus, it was feasible to use the Chebyshev–Ritz method to solve the eigenfrequencies of the horn-gear system in ultrasonic gear honing

Design and Simulation of 3-DOF Reconfigurable Planar Parallel Robot

This paper presents the design approach for 3-DOF (degrees-of-freedom) reconfigurable planar parallel mechanism (RPPM) with modular kinematic limbs and hybrid platform. Using the proposed approach, a series of kinematic models with rotatability are obtained. At first, the main models of PPMs are constructed. Then a series of configuration models of PPM modules are reconstructed. And the new configuration families of 3-DOF PPMs are obtained. Finally, the motion trajectories of three driven layout configurations are simulated, and the results show that the hybrid-loop platform can expand the workspace of PPM. Especially, the configurations of the PPM can transform from the two operations modes to the original mode

Design and Simulation of 3-DOF Reconfigurable Planar Parallel Robot

This paper presents the design approach for 3-DOF (degrees-of-freedom) reconfigurable planar parallel mechanism (RPPM) with modular kinematic limbs and hybrid platform. Using the proposed approach, a series of kinematic models with rotatability are obtained. At first, the main models of PPMs are constructed. Then a series of configuration models of PPM modules are reconstructed. And the new configuration families of 3-DOF PPMs are obtained. Finally, the motion trajectories of three driven layout configurations are simulated, and the results show that the hybrid-loop platform can expand the workspace of PPM. Especially, the configurations of the PPM can transform from the two operations modes to the original mode