Sustainable organic electrode materials, as promising alternatives to conventional inorganic electrode materials for sodium‐ion batteries (SIBs), are still challenging to realize long‐lifetime and high‐rate batteries because of their poor conductivity, limited electroactivity, and severe dissolution. It is also urgent to deeply reveal their electrochemical mechanism and evolution processes. A porous organic polymer (POP) with a conjugated and hierarchical structure is designed and synthesized here. The unique molecule and structure endow the POP with electron delocalization, high ionic diffusivity, plentiful active sites, exceptional structure stability, and limited solubility in electrolytes. When evaluated as an anode for SIBs, the POP exhibits appealing electrochemical properties regarding reversible capacity, rate behaviors, and long‐duration life. Importantly, using judiciously combined experiments and theoretical computation, including in situ transmission electron microscopy (TEM), and ex situ spectroscopy, we reveal the Na‐storage mechanism and dynamic evolution processes of the POP, including 12‐electron reaction process with Na, low volume expansion (125–106% vs the initial 100%), and stable composition and structure evolution during repeating sodiation/de‐sodiation processes. This quantitative design for ultrafast and highly durable sodium storage in the POP could be of immediate benefit for the rational design of organic electrode materials with ideal electrochemical properties.

A novel miniaturised dual-band bandpass filter (BPF) based on defected split-ring resonators (SRRs) and irregular stepped-impedance resonators (SIRs) is proposed. By applying defected SRRs embedded with eight combinations of three whole or broken grooves, which are formerly used for divination, the passband of 2.35-2.52 GHz with wideband harmonic suppression is achieved for WLAN applications. To create one more passband of 5.09-5.3 GHz, the irregular SIRs are etched inside the defected SRRs. Finally, such a prototype is designed and fabricated with the dimension of only 20 × 20 mm 2 (0.27λ g × 0.27λ g). The measured results of this dual-band BPF agree well with the simulations verifying the proposed idea.

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In this paper, a vector Monte Carlo (MC) method is proposed to study the influence of atmospheric scattering on polarization qubits for satellite-based quantum communication. The vector MC method utilizes a transmittance method to solve the photon free path for an inhomogeneous atmosphere and random number sampling to determine whether the type of scattering is aerosol scattering or molecule scattering. Simulations are performed for downlink and uplink. The degrees and the rotations of polarization are qualitatively and quantitatively obtained, which agree well with the measured results in the previous experiments. The results show that polarization qubits are well preserved in the downlink and uplink, while the number of received single photons is less than half of the total transmitted single photons for both links. Moreover, our vector MC method can be applied for the scattering of polarized light in other inhomogeneous random media.