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This paper introduces the technical transformation and system realization of the hoister gap monitoring and protection device in Hongyang No.2 Coal Mine. Through the high-precision laser displacement sensor, we detected displacement signals, such as brake clearance, brake wear value, spring fatigue and brake disc deflection, to convert into 4-20 mA current signal to transmit to the PLC analog input port. PLC can read, analyze and convert the data in real time, and convert it into numerical value which is easy to display. Sound and light alarm signal is sent when the set value is exceeded. The practical application proves that the device has the technical characteristics of high sensitivity, strong anti-interference ability and reliable operation.

Convenient chemical modification of biomacromolecules to create novel biocompatible functional materials satisfies the current requirements of sustainable chemistry. Dendronization of chitosan with dendritic oligoethylene glycols (OEGs) paves a strategy for the preparation of functional dendronized chitosans (DCSs) with unprecedent thermoresponsive behavior, which inherit biological features from polysaccharides and the topological features from dendritic OEGs. In addition, densely packed dendritic OEG chains around the backbone provide efficient cooperative interactions and form an intriguing confined microenvironment based on the degradable biopolymers. In this perspective, we describe the principle for the preparation of the thermoresponsive DCSs, and focus on the molecular envelop effect from the hydrophobic microconfinement to the encapsulated guest molecules or moieties. Particular attention is put on their capacity to regulate behavior and the functions of the encapsulated guests through thermally-mediated dehydration and collapse of the densely packed dendritic OEGs. We believe that the methodology described here may provide prospects for the fabrication of functional materials from biomacromolecules, especially when used as environmentally friendly nanomaterials or in accurate diagnosis and therapy. [ABSTRACT FROM AUTHOR]

α-Amino ketones are important motifs in synthetic and medicinal chemistry. Efficient methods to directly access these motifs from feasible precursors are, however, limited. Herein, a visible-light mediated reductive cross-electrophile coupling of readily available imines and anhydrides was developed. Under mild reaction conditions, the umpolung reactivity of diverse imines engaged with anhydrides gives a variety of α-amino ketones with good yields and a broad functional group compatibility. Primary mechanistic studies revealed that this transformation might proceed through a radical–radical cross coupling pathway dominantly. [ABSTRACT FROM AUTHOR]

It is fundamental for gene transformation and ecosystem hazard evaluation to study the pollen characteristics of transgenic plants. In this research, the characteristics of pollen from 7- or 8-year-old transgenic apple plants carrying an exogenous CpTI gene were analyzed. The results showed that there was no significant difference in terms of size, morphology, or exine ornamentation between the pollen of the transgenic plants and the non-transgenic control. However, the transgenic plants had more abnormal pollen grains. Of the 13 transgenic lines tested, 12 had a significantly lower amount of pollen and six exhibited a significantly lower germination rate when cultured in vitro. The pollen viability of three transgenic lines was determined, with two showing significantly lower viability than the control. The transgenic Gala apple pollen grains germinated normally via controlled pollination on Fuji apple stigmas. However, the pollen tubes extended relatively slowly during the middle and late development stages, and another 8 h were needed to reach the ovules compared with the control. The gibberellic acid concentration in transgenic Gala apple flowers was lower than in the non-transgenic control during all development stages tested. The abscisic acid concentration in the transgenic flowers was lower during the pink stage, and higher during the ball and fully open stages. Microscopic observation of the anther structure showed no difference. The tapetum of the pollen sac wall in transgenic plants decomposed late and affected pollen grain development, which could be one of the reasons for the lower number of pollen grains and poor viability in the transgenic plants.

Anti‐icing polyimide (PI) thin films are a promising anti‐icing technology for aircraft. A processing method combining reactive ion etching with cooling and plasma chemical vapour deposition is proposed to fabricate anti‐icing PI thin films with microcolumns (PI‐M). The anti‐icing performance of PI‐M was examined. The apparent contact angle (APCA) was 153° ± 1.4°, and the APCA hysteresis was 8.5° ± 0.5°. The calculated Weber number was high, and a droplet on PI‐M rebounded within 2.56 s, whereas rebounding occurred more slowly on a smooth PI surface (PI‐S). The freezing time of droplets on PI‐M was 70% longer than that on PI‐S. The average ice adhesion force on PI‐M was 42% smaller than that on PI‐S. Repeated measurements of the ice adhesion force on PI‐M demonstrated that it was stable (deviation: ±1 N). The APCA showed that PI‐M is superhydrophobic, which indicates that droplets on PI‐M were in the Cassie state. The droplet bouncing behaviour was explained in terms of horizontal force equilibrium at the interface. The anti‐icing mechanism of PI‐M was modelled using heterogeneous nucleation theory and a contact area model. The results explained the good anti‐icing performance and suggested that PI‐M may have excellent potential for anti‐icing applications. [ABSTRACT FROM AUTHOR]