Analysis of rice characteristic volatiles and their influence on rice aroma.

Rice aroma, one of the most important qualities of rice, was the comprehensive result of volatiles in rice and human sense. In this study, the main volatile compounds in rice were analyzed by using gas chromatography-mass spectrometry and gas chromatography-olfactometry, and their correlations with sensory score were investigated. A total of eighty-five volatiles were found in rice samples. By combining odor activity value and correlation analysis, nine volatiles were considered as potential characteristic volatiles in rice aroma, namely hexanal, 2-pentylfuran, octanal, 2-acetyl-1-pyrroline (2-AP), 1-octen-3-ol, trans-2-octenal, decanal, trans-2-nonenal and trans, trans-2,4-decadienal. It was found that the volatiles negatively correlated with sensory scores were positively correlated with hexanal. It indicated that hexanal might be a representative of the negative volatiles of rice aroma. The effects of the nine potential characteristic volatiles on rice aroma were investigated by using sensory analysis. The results showed that the odor intensity and preference level of 2-AP, hexanal, and 1-octen-3-ol were significantly affected by the content. Furthermore, the aroma of cooked rice was significantly different after adding 2-AP, hexanal or trans, trans-2,4-decadienal. Rice aroma was increased by adding 2-AP and deteriorated by adding hexanal or trans, trans-2,4-decadienal, indicating that 2-AP contributed positively to rice aroma while hexanal and trans, trans-2,4-decadienal contributed negatively to rice aroma. Hexanal, 2-AP, and trans, trans-2,4-decadienal were suggested to be the key characteristic volatiles for future aroma evaluation.

Reflection of Laguerre-Gaussian beams carrying orbital angular momentum: a full Taylor expanded solution.

Partial reflection of linearly polarized Laguerre-Gaussian beams incident at a dielectric interface are studied beyond the paraxial regime. Based on the angular spectrum method and Taylor series expansion, we derive exact analytical expressions for the reflected electric field. This result holds in both the paraxial and nonparaxial regimes. The result is then extended to beams of arbitrary polarization and used to analytically calculate the transverse and longitudinal shifts of the beams' center of gravity. Finally, several numerical examples are performed to verify the analytical formulas we derived near the Brewster angle.

Optical aperture synthesis imaging with fractional Fourier-domain filtering.

The fractional Fourier transform, which is a generalization of the classical Fourier transform, is introduced into an optical aperture synthesis (OAS) system by which imaging of an astronomical object can be achieved. We introduce fractional Fourier optical imaging and fractional Fourier-domain filtering (FFDF), and then present the schematic diagram of an OAS imaging system with FFDF. The modulation transfer function of an OAS system with FFDF is compared with that of an OAS system in the same condition. The result indicates that the OAS system with FFDF has larger practical cutoff frequency when the fill factor is smaller. Furthermore, the quality of imaging and restoration also demonstrates this conclusion.

Adaptive deep learning-based neighborhood search method for point cloud.

Point cloud processing is a highly challenging task in 3D vision because it is unstructured and unordered. Recently, deep learning has been proven to be quite successful in point cloud recognition, registration, segmentation, etc. Neighborhood search operation is an important component of point cloud deep learning models, and directly affects the performance of the model. In this paper, we propose a learnable neighborhood search method. This method adaptively chooses an appropriate search method based on the characteristics of each point, thus avoiding the disadvantage of selecting the search method manually. We validate the proposed methods on ModelNet40 dataset and ShapeNetPart dataset, and all the chosen models achieved a performance improvement with a maximum improvement of 1.1%. The proposed method is a plug-and-play technique and can be easily integrated into existing methods.

Passive interferometric array optimization based on redundant spacing calibration.

An optimization of passive interferometric circular arrays for redundant spacing calibration (RSC) is advanced to eliminate phase errors of the array system. The principle of RSC is presented to solve corresponded constraints for passive interferometric circular arrays. The simulated annealing algorithm (SAA) is introduced to settle the array optimization with a criterion of maximizing the distance between u-v points. The optimized circular arrays with element numbers of 8 to 16 antennas are laid out, and RSC is used for the optimized ten-element passive interferometric circular array.

An Algorithm to retrieve aerosol properties from analysis of multiple scattering influences on both Ground-Based and Space-Borne Lidar Returns.

A new method is proposed to analyze the effects of multiple scattering on simultaneously detected lidar returns for ground-based and space-borne lidars, and it is applied to a Monte Carlo-based simulation to test the feasibility of the new method. The experimental evidence of multiple scattering influences on both ground-based and space-borne lidar returns is presented. Monte Carlo-based evaluations of the multiple scattering parameters for the counter-looking lidar returns are separately obtained in order to correct the effective values of backscattering and extinction coefficients. Results show that for the typical cirrus cloud, the presence of the multiple scattering can lead to an underestimation of the extinction coefficient by as large as 70%, and the backscattering coefficient is overestimated by nearly 10%, which are retrieved by the Counter-propagating Elastic Signals Combination (CESC) technique in which the multiple scattering influences are neglected. Nevertheless, by the new method in which the multiple scattering effects are considered differently for the ground-based and space-borne lidar returns the extinction and backscattering coefficients can be more accurately obtained.

In Situ Formation of Decavanadate-Intercalated Layered Double Hydroxide Films on AA2024 and their Anti-Corrosive Properties when Combined with Hybrid Sol Gel Films.

A layered double hydroxide (LDH) film was formed in situ on aluminum alloy 2024 through a urea hydrolysis method, and a decavanadate-intercalated LDH (LDH-V) film fabricated through the dip coating method. The microstructural and morphological characteristics were investigated by scanning electron microscopy (SEM). The corrosion-resistant performance was analyzed by electrochemical impedance spectroscopy (EIS), scanning electrochemical microscopy (SECM), and a salt-spray test (SST).The SEM results showed that a complete and defect-free surface was formed on the LDH-VS film. The anticorrosion results revealed that the LDH-VS film had better corrosion-resistant properties than the LDH-S film, especially long-term corrosion resistance. The mechanism of corrosion protection was proposed to consist of the self-healing effect of the decavanadate intercalation and the shielding effect of the sol-gel film.