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Micro-seismic monitoring technology has become a fundamental method for deep-ground pressure research and management. Based on the IMS micro-seismic monitoring system, the micro-fractures of rock mass caused by the mining process of Chifeng NFC Baiyinnuoer lead-zinc mine are monitored, it can accurately reflect the stability of the goafs and production operation stopes in the target areas. Data analysis shows that; 1) By analyzing the spatiotemporal distribution of micro-seismic events, using b-value method and the methods of relationships between energy index(EI) and cumulative apparent volume(CAV), as well as Schmidt number(Scs) and CAV, combined with on-site construction conditions, micro-seismic data can be more accurately analyze and the overall stability of underground mining sites can be evaluate effectively to draw reasonable conclusions; 2) On the premise of El decreases, the slip in slope of the CAV curve at the inflection points corresponds to an decrease in the probability of occurrence of micro-seismic events or the number of micro-seismic events compared to the last previous values, and vice versa; On the premise of Scs decreases, regardless of the rise or fall in the slope of the CAV curve at the inflection points, the probability of occurrence of micro-seismic events or the number of micro-seismic events compared to the last previous values both decrease; 3)The frequency of occurrence of aftershock events caused by large explosions in the underground mining area of this nonferrous metal mine has significantly decreased, a good stability of the production site could be demonstrated. The application of this system will play a positive role in earthquake prevention, disaster reduction, and safety production in the underground mining of Chifeng NFC Baiyinnuoer lead-zinc mine. [ABSTRACT FROM AUTHOR]

Conductive structures determine the functions and actuation modes of electrically responsive soft actuators. The rewritability of conductive structures is highly desirable but has not been realized in electro‐driven actuators. Typically, once conductive pathways are established, they can hardly be modified; thus, the function of the actuator is permanently fixed. In this study, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is developed as a rewritable conductive coating for actuators composed of liquid crystalline elastomers (LCEs). This enables reconfigurable, adaptive, and precisely controllable electro‐driven motions and the repeated use of the same actuator for various purposes without disposal. Moreover, different PEDOT:PSS layers can be coated onto different regions, thus enabling the assembly of different actuation behaviors in a monolithic actuator under a single input voltage. Unlike all previously reported soft actuators that respond to electricity and light, opposite shape changes in an actuator with a series circuit can be performed under these two stimuli. Furthermore, when combining LCEs with dynamic covalent bonds, the PEDOT:PSS‐coated LCE (PEDOT:PSS‐LCE) actuator can be reprogrammed based on two different mechanisms: rewriting the conductive PEDOT:PSS patterns and re‐aligning the LCEs. This versatile method can be adapted to other types of actuators. [ABSTRACT FROM AUTHOR]

Liquid crystalline elastomers are regarded as a kind of desirable soft actuator material for soft robotics and other high-tech areas. The isotropization temperature (Ti) plays an important role as it determines the actuation temperature and other properties, which in turn has a great effect on their applications. In the past, the common physical methods (e.g. annealing) to tune Ti is not applicable to tune the actuation temperature. The new Ti obtained by annealing immediately goes back to the old one once it is heated to a temperature above Ti, while actuation needs a temperature higher than Ti. For a fully cross-linked LCE material, once it is synthesized, the actuation temperature is fixed. Accordingly, the actuation temperature can not be tuned unless the chemical structure is changed, which usually needs to start from the very beginning of the molecular design and material synthesis. Here, we found that different Ti achieved by annealing can be preserved by reversible reactions of dynamic covalent bonds in covalently adaptable LC networks including LC vitrimers. Thus, a variety of soft actuators with different actuation temperatures can be obtained from the same fully cross-linked LCE material. As the tuning of Ti is also reversible, the same actuator can be adjusted for applications with different actuation temperature requirements. Such tuning will also expand the application of LCEs. Isotropization temperature determines the temperature at which Liquid Crystals Elastomer (LCE) material actuates. Here, the authors give a general strategy based on dynamic covalent bonds for tuning the isotropization temperature for LCEs. [ABSTRACT FROM AUTHOR]