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The electromagnetic wave energy emitted by wireless communication equipment in coal mines can be coupled and absorbed by surrounding metal structures, which poses a risk of igniting explosive gases in the mine. The existing research on the safety of underground metal structure coupled electromagnetic waves only focuses on the analysis of the energy of metal structure equivalent impedance model coupled electromagnetic waves. It lacks research on the energy storage process of metal structure coupled electromagnetic wave energy accumulated over time. In order to solve the above problems, an equivalent energy storage structure model suitable for studying the coupling-accumulation-release electromagnetic wave energy of metal structures is proposed, namely the metal structure equivalent capacitive energy storage model and the metal structure equivalent inductive energy storage model. Firstly, by using a low attenuation transmission line model, the relationship between the output power of the transmitting antenna, the distance between the transmitting antenna and the metal structure, and the induced voltage at the receiving end is derived. Secondly, an equivalent energy storage model of metal structure is established. The mathematical relationship between the receiving end parameters and the discharge spark energy is derived. The influence of the receiving end parameters on the discharge spark energy is analyzed. Finally, the mathematical relationship between the output power of the transmitting antenna, the distance between the transmitting antenna and the metal structure, and the discharge spark energy is derived by analyzing the relationship between the induced voltage at the receiving end and the effective value of the induced voltage. The influence of the output power of the transmitting antenna and the distance between the transmitting antenna and the metal structure on the discharge spark energy is analyzed. The theoretical reference safety points of the equivalent energy storage models of the two metal structures are given under the condition of other parameters being determined. The simulation results show the following points. ① For the equivalent capacitive energy storage model of metal structures, the discharge spark energy increases with the increase of the effective values of the equivalent energy storage capacitor and the induced voltage at the receiving end, and the safety point shifts to the left. The safety requirements for the effective values of the equivalent energy storage capacitor and the induced voltage at the receiving end become stricter. ② The energy of the discharge spark increases with the increase of the transmitting antenna power, and decreases with the increase of the distance between the transmitting antenna and the metal structure. The theoretical reference safety point of the equivalent capacitive energy storage model of the metal structure is obtained. ③ For the equivalent inductive energy storage model of metal structures, the discharge spark energy increases with the increase of the effective values of the equivalent energy storage inductance and the induced voltage at the receiving end, and the safety point shifts to the left. The safety requirements for the effective values of the equivalent energy storage inductance and the induced voltage at the receiving end become stricter. ④ The energy of the discharge spark increases with the increase of the transmitting antenna power, and decreases with the increase of the distance between the transmitting antenna and the metal structure. The theoretical reference safety point of the equivalent inductive energy storage model of the metal structure is obtained. ⑤ Comparing the theoretical reference safety points of two metal structure energy storage models, it is concluded that the danger of the metal structure equivalent capacitive energy storage model is much greater than that of the metal structure equivalent inductive energy storage model.

To study the problem that there is a horizontal sidesway between transfer and receiver coils in magnetic resonance coupling wireless power transfer, the mutual inductance coupling theory and twoport network theory is adopting for modeling analysis.The expression of normalized transmission power and transmission efficiency expressed by s parameter by mathematical derivation.The HFSS software is utilized to simulate the impact of the horizontal sidesway on system's transmission performance under the condition of overcoupling, critical coupling and undercoupling.An optimal structure for improving the system is presented.In the end, the reliability of simulation results is verified by experiment, and the experiment proves that the optimized structure should eliminate the negative effect brought by the sidesway effectively, and improve the transmission efficiency of the system.

Principle of magnetic resonance coupling wireless power transmission system was analyzed by use of mutual inductance theory. Impedance matching theory and corresponding parameter calculation methods were introduced. A model of magnetic resonance coupling wireless power transmission system containing an impedance matcher was built by equaling variation of mutual inductance between sending coil and receiving coil to variation of the system impedance parameters. The simulation result proves that magnetic resonance coupling wireless power transmission system containing an impedance matcher can improve load power effectively under the same condition.

Requirements of coal mine underground were analyzed for wireless power energy transmission. Characteristics of three kinds of wireless power transmission technologies were researched including microwave type, electromagnetic induction and magnetic coupling resonant type as well as their applicability in coal mine underground. It was considered that magnetic coupling resonant type wireless power transmission technology could be applied in coal mine underground. Impacts of different obstacles were analyzed emphatically on transmission efficiency of magnetic coupling resonant wireless power transmission system. A simulation model of magnetic coupling resonant wireless power transmission system was built by using HFSS 3D electromagnetics simulation software, and simulated experiments were carried out using metallic obstacles and the nonmetallic ones. The experimental results show that nonmetallic obstacles have no influence on transmission efficiency of the system, and metallic obstacles reduce transmission efficiency, especially in condition of adding thickness or reducing lateral area of the metallic obstacles.

Cytosolic Ca2+ is a highly dynamic, tightly regulated and broadly conserved cellular signal. Ca2+ dynamics have been studied widely in cellular monocultures, yet organs in vivo comprise heterogeneous populations of stem and differentiated cells. Here, we examine Ca2+ dynamics in the adult Drosophila intestine, a self-renewing epithelial organ in which stem cells continuously produce daughters that differentiate into either enteroendocrine cells or enterocytes. Live imaging of whole organs ex vivo reveals that stem-cell daughters adopt strikingly distinct patterns of Ca2+ oscillations after differentiation: enteroendocrine cells exhibit single-cell Ca2+ oscillations, whereas enterocytes exhibit rhythmic, long-range Ca2+ waves. These multicellular waves do not propagate through immature progenitors (stem cells and enteroblasts), of which the oscillation frequency is approximately half that of enteroendocrine cells. Organ-scale inhibition of gap junctions eliminates Ca2+ oscillations in all cell types - even, intriguingly, in progenitor and enteroendocrine cells that are surrounded only by enterocytes. Our findings establish that cells adopt fate-specific modes of Ca2+ dynamics as they terminally differentiate and reveal that the oscillatory dynamics of different cell types in a single, coherent epithelium are paced independently.