The causes and pathogenesis of sensitive skin are relatively complex. Herein, the causes and pathogenesis of sensitive skin are summarized based on previous research results. The causes of sensitive skin mainly include various external factors, internal factors, and other dermatological factors. The mechanisms are complex, including skin barrier function injury, changes in epidermal microbial status, abnormal sensory nerve fiber function, activation of TRPV1 channel, neurovascular-immune-inflammatory pathway, transcriptome, etc. Sensitive skin is often induced by multiple mechanisms. The analysis and discussion of the causes and mechanisms of sensitive skin will be helpful to guide clinical practice.

The urban-rural transformation from dichotomy to integration is a gradual process.Like rural areas in many countries,Chinese rural society is experiencing a decline in all spheres due to depopulation,aging,lack of economic opportunity,and so on.Aiming at solving the serious rural issues,China proposed the implementation of a rural revitalization strategy and the promotion of an integrated urban-rural development for the first time in 2017.This proposal marks the transformation of the urban-rural relationship,and the integrated urban-rural development reflects a significant conceptual change.Researches on issues of rural decline are urgently needed to determine the most effective method for rural revitaliza-tion and development from the perspective of the urban-rural dynamics.In this context,this paper focuses on studying the theory,technology and management of rural revitalization and development.We construct a theoretical framework for urban-rural integration based on population-land-industry-right between the urban and rural systems,regarding land engi-neering for land capacity building as the technical support and the rural land system reform and reconstruction as the policy support for management.This research will provide theo-retical support for the implementation of China's rural revitalization strategy.

In this paper we developed a parallel code, adopting a fifth-order weighted essentially non-oscillatory (WENO) scheme with a third-order TVD Runge-Kutta time stepping method for the two-dimensional reactive Euler equations, to investigate the propagation process of methane explosion in bend ducts. In the simulations, an inverse Lax-Wendroff procedure is adopted to construct a high order boundary in order to treat the complex boundaries. The numerical results show that when the bend angle is 30 degrees and 45 degrees, it cannot inhibit the propagation of the detonation wave: while when the angle reaches 60 degrees and 75 degrees, the detonation wave finally attenuates to the shock wave. It indicates that the propagation of the detonation wave can be inhibited. Furthermore, the temperature and the pressure at the entrance of the bend are low. When the angle arrives at 90 degrees, the detonation wave evolves into cellular detonation when it passes through the bend. When the angle is larger than 90 degrees, the detonation wave dramatically attenuates at the diffracting point, and later some hot spots can be formed, which can ignite the combustible gas nearby. Thus the second explosion occurs and finally the detonation is formed. When the angle is larger than or equal to 90 degrees, the temperature and the pressure at the entrance of the bend is too high that the rescue efforts in the methane explosion accidents will encounter great difficulties. Hence, the laneway with 60 degrees and 75 degrees bend can inhibit the propagation of the detonation wave, and the temperature and the pressure at the entrance of the bend is not too high as well. All the results above can provide an important basis for the design and optimization of the mine laneway. (C) 2011 Elsevier Ltd. All rights reserved.

The soft millirobot is a promising candidate for emerging applications in various in-vivo/vitro biomedical settings. Despite recent success in its design and actuation, the absence of sensing ability makes it still far from being a reality. Here, a radio frequency identification (RFID) based battery-less soft millirobot that can move, sense, and communicate remotely by coupling the magnetic and piezoelectric effects is reported. This design integrates the robot actuation and power generation units within a thin multilayer film (<0.5 mm), i.e., a lower magnetic composite limb decorated with multiple feet imparts locomotion and a flexible piezoceramic composite film recovers energy simultaneously. Under a trigger of external magnetic guidance, the millirobot can achieve remote locomotion, environment monitoring, and wireless communication with no requirement of any on-board battery or external wired power supply. Furthermore, this robot demonstrates the sensing capability in measuring environment temperature and contact interface by two different sensing models, i.e., carried-on and build-in sensing mode, respectively. This research represents a remarkable advance in the emerging area of untethered soft robotics, benefiting a broad spectrum of promising applications, such as in-body monitoring, diagnosis, and drug delivery.