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Aiming at the potato cropping pattern in the hilly area of southwest China, a small digging device for potato harvester was designed. First, the overall structure of the harvester was determined according to the soil physical characteristic and cropping pattern of the test site. Then, the digging shovel, the key components of harvester were designed and was analyzed the relationship between the inclination of the digging shovel and the power loss under the conditions of different digging speed, digging depth and soil bulk density by MATLAB software, and the mathematical models were established. Finally, the three-dimensional model of the whole machine was established by SolidWorks, and the simulation experiment was carried out with the model of soil particles, potato particles and potato ridges created by the discrete element (DEM) software. The simulation results show that when the working speed of the harvester is 1 m/s, the digging depth is 170 mm, and the potato expose rate is 87.3%. Under normal working conditions of the digging device, appropriately reducing the digging depth can reduce the resistance and wear of the digging shovels.

Spintronics, that is, the utilization of electron spin to enrich the functionality of microelectronics, has led to the inception of numerous novel devices, particularly magnetic random-access memory (MRAM). Over the last decade, significant effort has been devoted to magnetization manipulation using spin-orbit torque (SOT), which shows great promise for ultrafast and energy-efficient MRAM. In this Perspective, we summarize the latest progress in the study of SOT and highlight some of the technical challenges facing the development of practical SOT devices. After introducing the basic concepts of SOT and its relevance for magnetization switching, we will focus on several methods to realize deterministic SOT switching in the absence of an external field, which is a requirement for practical SOT devices. Additionally, we summarize the materials used in SOT devices. The final section is devoted to the most important recent advances in the application of SOT devices, including SOT-MRAM, spin logic, spin Hall nano-oscillators, and neuromorphic devices.

With the rapid development of the mobile devices, there arouses great interest in mobile health service. As a new phenomenon, previous studies tend to investigate the adoption behavior in terms of the general population or one special population. In order to target more populations as potential customers, our study will use protection motivation theory (PMT) to explain the mobile health services acceptance of difference age groups. During the research, the hypothesized model is tested using data collected from a field survey of 492 potential customers of three difference age groups. The results revealed that response efficacy and self efficacy had a significant impact on adoption intention for the group of young adults and middle age people, while for the group of the elderly, only self efficacy determined the intention to use mobile health service. Theoretical and practical implications are discussed.

In the traditional visual cryptography schemes, only one piece of image was encoded during encryption. And each of the shares that are generated was shown as a disorganized image. Due to the capacity of encrypted information, these schemes have few applications and because of the disorganized image share, they are easily suspected by hacker. In order to solve these problems, an Extended Visual Cryptography Scheme with multiple secrets hidden is proposed. Meaningful shares are generated by utilizing the principle of contrast and multiple secret images may be hidden by changing the overlapping angle of the shares. The scheme may also apply to color image which has been processed by halftone technology. The scheme is easy and effective and the shares also have sufficient security level.