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In triangular-lattice magnets, the coexistence of third-neighbor antiferromagnetic and nearest-neighbor ferromagnetic exchange interactions can induce rich magnetic phases including noncoplanar skyrmion crystals. Based on Monte Carlo simulation, we studied the dependence of magnetic phase transition on exchange interaction strength. Under the consideration of uniaxial anisotropy and magnetic field both perpendicular to the film plane, a large antiferromagnetic exchange interaction induces a high frustration. When the value of antiferromagnetic exchange interaction is one and a half times larger than the ferromagnetic one, a magnetic phase composed of canting spin stripes, never observed in the chiral magnets, forms. Interestingly, different canting spin stripes along three 120 degree propagation directions may coexist randomly in a magnetic phase, attesting that the canting spin stripes are three-fold degenerate states akin to helices and the multiple state of canting spin stripes is a circular configuration with zero skyrmion charge number. Moreover, skyrmions and antiskyrmions can be observed simultaneously in the configuration at the low temperature nearly close to 0 K, and their configuration and diameter properties are discussed. Finally, the mechanisms of skyrmion creation and annihilation are properly interpreted by comparing exchange and Zeeman energy terms.

The objective of the autonomous navigation aims to achieve the self-motion control for a robot with the environmental feedbacks and becomes popular recently. Problems of complex modeling, large amount of calculation, and lacking of environmental information always exist in autonomous navigation methods. This article proposes a self-navigation method with a fuzzy three-dimensional grid depicted by dual two-dimensional grid maps. Meanwhile, a synthetic preprocess is presented to perform localization through switching among the weighted three-point localization method, the two-point localization method, and the weighted average localization method. For reducing the amount of calculation, an improved fuzzy three-dimensional grid mapping method where the three-dimensional map is described by dual two-dimensional grid maps, the identifier map, and the height map is designed. Especially, the static and dynamic information within the map are divided and updated fuzzily. The global path planning is performed with the static information, and the real-time obstacle avoidance is conducted with the dynamic information. The results of simulations and experiments demonstrate that the proposed method has better properties in efficiency of navigation and lower amount of calculation than the competing methods.

Medium-temperature Daqu (MT-Daqu), a saccharification-fermentation agent and aroma-producing agent, is used to produce Chinese strong-flavor Baijiu. Many related studies have been published; however, less is known about microbial community and quality properties inside and outside the MT-Daqu from fermentation to storage. Here, along with determining the physicochemical index, the microbial community of MT-Daqu was investigated using both culture-dependent and culture-independent methods during 31 days of fermentation and 4 months of storage. Volatile compounds of mature MT-Daqu were analyzed using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC–MS). The results indicated obvious variation in the microbial community due to the changes in environmental conditions, and the physicochemical indices shifted from fluctuations in the fermentation period to relative stability after storage for 3 months. Moreover, the microbial counts and physicochemical indices of the inner layers of MT-Daqu differed from those of the outer layers. The dominant communities, including the bacterial phyla Firmicutes, Proteobacteria, and Actinobacteria and the fungal phyla Ascomycota and Mucoromycota, showed different abundances in the two parts of the mature MT-Daqu, and different microbial communities were enriched in both parts. Additionally, pyrazines and alcohols were the most abundant volatile aroma compounds in the mature MT-Daqu.

To improve the intelligence and accuracy of the Situation Assessment (SA) in complex scenes, this work develops an improved fuzzy deep neural network approach to the situation assessment for multiple Unmanned Aerial Vehicle(UAV)s. Firstly, this work normalizes the scene data based on time series and use the normalized data as the input for an improved fuzzy deep neural network. Secondly, adaptive momentum and Elastic SGD (Elastic Stochastic Gradient Descent) are introduced into the training process of the neural network, to improve the learning performance. Lastly, in the real-time situation assessment task for multiple UAVs, conventional methods often bring inaccurate results for the situation assessment because these methods don’t consider the fuzziness of task situations. This work uses an improved fuzzy deep neural network to calculate the results of situation assessment and normalizes these results. Then, the degree of trust of the current result, relative to each situation label, is calculated with the normalized results using fuzzy logic. Simulation results show that the proposed method outperforms competitors.

Recently, the dependence of exchange bias (EB) on ferromagnetic layer thickness (t FM ) and temperature has become a matter of controversy, triggering renewed research efforts to decipher the key aspects of these intriguing phenomena. To demonstrate these anomalous dependences linked to the ferromagnetic spin structures, a modified Monte Carlo method is used on models of NiFe/antiferromagnet and Fe/antiferromagnet bilayers where a twisted configuration is favored along the film depth in the ferromagnetic layer during magnetization reversals. It is found that the EB field deviates from the reciprocal relation with t FM towards a lower value as t FM increases, and the maximum value of the EB field with temperature appears at 97 K for NiFe and 123 K for Fe, not the lowest temperature. The decrease in the EB field with t FM may also depend on the thickness of the antiferromagnetic layer and the twisted angle. The twisted configuration formed in a thick ferromagnetic layer encourages the propagation of domain walls through the ferromagnetic film to decrease the external switching field, leading to a suppressed EB. On the other hand, this twisted configuration simultaneously widens the domain walls and removes the unstable pinning points at relatively high temperatures. As a result, EB is recovered.