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Research on biomechanical properties of skin and its detection method is significant in learning about and mastering the physiological function of the skin, assessing the degree of skin aging correctly as well as doing some appropriate care. As one of the important indexes for skin mechanics, viscoelastic can reflect the state of skin system timely, and play a guiding role in the treatment of diseases related. Meanwhile, surgery recuperation and cosmetics can be effectively measured and quantified. Due to the uniqueness and complexity of the structure of skin, the test method for its viscoelasticity is more complex than engineering meterial. In recent years, detection technology of skin viscoelastic has been paid great attention, especially to the non-invasive methods of skin viscoelastic. In this paper, the principle of non-invasive detection methods and their recent development are described, and the various detection methods and the major equipments are also analyzed.

To improve the flavour quality of bayberry juice, effects of different raw materials, heat treatment and storage time on the flavour variations were investigated. Changes of total sugar and titratable acids were also monitored. Identification and quantitation of volatile flavour compounds were performed by headspace solid-phase microextraction couped with gas chromatography–mass spectrometry (HS-SPME–GC–MS). The contents of esters, alcohols, total sugar and titratable acidity of the rancid flavour raw juice were 6.03%, 8.24%, 5.56 g/L, 0.18 g/L less than those of pleasing flavour raw juice (PF), while the content of aldehydes was 4.19% higher than that of PF. After 9 months storage, the bayberry juice produced fermentation-like flavours with alcohols increases (11.45%) while esters (14.91%) and total sugar (3.27 g/L) decreases. The results suggested that proper juice processing and storage techniques are critical to the flavour quality of bayberry juice.

The double pulse sources (DPS) method is presented for linear track estimation in this work. In the field of noise identification of underwater moving target, the Doppler will distort the frequency and amplitude of the radiated noise. To eliminate this, the track estimation is necessary. In the DPS method, we first estimate bearings of two sinusoidal pulse sources installed in the moving target through baseline positioning method. Meanwhile, the emitted and recorded time of each pulse are also acquired. Then the linear track parameters will be achieved based on the geometry pattern with the help of double sources spacing. The simulated results confirm that the DPS improves the performance of the previous double source spacing method. The simulated experiments were carried out using a moving battery car to further evaluate its performance. When the target is 40–60m away, the experiment results show that biases of track azimuth and abeam distance of DPS are under 0.6o and 3.4m, respectively. And the average deviation of estimated velocity is around 0.25m/s.

Microwave-assisted spouted bed (MSBD) drying of lettuce cubes was investigated experimentally. Response surface methodology was used to optimize the process with spouting air temperature, microwave power level, and superficial air velocity. The dried product obtained was compared with that obtained using other drying technologies such as hot air drying, air spouted bed drying, vacuum microwave drying, and vacuum freeze drying. The comparison is based on the rehydration ratio, chlorophyll content of the product, color, and the drying time required.

The phase difference method (PDM) is presented for the direction of arrival (DOA) estimation of the narrowband source. It estimates the DOA by measuring the reciprocal of the phase range of the sensor output spectra at the interest frequency bin. The peak width and variance of the PDM are presented. The PDM can distinguish closely spaced sources with different and unknown center frequencies as long as they are separated with at least one frequency bin. The simulation results show that the PDM has a better resolution than that of the conventional beamforming.

A new method uses a linear array that takes advantage of underwater physical sound fields to estimate the velocity of an underwater moving target. The mathematical model was established by considering the geometric relationship between the moving target installed with only two transducers to radiate sound of different frequencies and the linear array. In addition, deterministic maximum likelihood and signal phase matching algorithms were introduced to effectively find the directions of arrival (DOAs) of the sound sources of the two transducers installed on the target. Factors causing velocity measurement errors were considered. To track the target, a linear array with a compass, a pressure transducer, a signal conditioner and a digital recorder was configured. Relevant requirements for the array parameters were derived. The simulation showed that a 16-element array with an aperture of less than 1m can measure velocity with relative error of no more than 4% when including typical system errors. Anechoic pool and reservoir experiments confirmed these results.

Eight different combinations of pretreatments and storage methods (freezing rate, maltose treatment and storage temperature) were applied to frozen kiwifruit slices, and the effect of these treatments on the qualities (color, water content, chlorophyll content, ascorbic acid content and cell structure) were evaluated. Color, water content, chlorophyll and ascorbic acid contents of frozen kiwifruit stored below the glass transition temperature (Tg′) were higher than those of kiwifruit slices stored above the glass transition temperature, and the cell structure of the former were more integrated than that of the later. The effects of freezing rate and sugar treatment on the qualities of frozen kiwifruit slices showed diversity according to the experimental factors and index.

A new method of estimating the frequency-known signals from the strong background noise was presented first. Then the new method was used in the demodulation of the digital frequency modulation (FSK) signals. The new demodulation method can complete the demodulation of the FSK signals only with the carrier frequency and without any carrier phase information. The simulation results show that the performance of anti-noise of the new method is better than that of the incoherent demodulation method and the fluctuation of the carrier phase has little effect on the new method. So the new demodulation method has a fine prospect in the practical applications.