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This paper mainly studies the solution of the electromagnetic ring network. Firstly, the current situation and main problems of the electromagnetic ring network are analyzed, then the principles and ideas of the electromagnetic ring network are studied, and then the effect of the electromagnetic ring network is analyzed through example verification. Through the above research, it is concluded that the development and construction of the power grid should be accelerated in combination with the load and power supply planning to create conditions for decoupling the electromagnetic loop network and eliminate the adverse effects of the operation of the electromagnetic loop network.

The 3-DOF micro-nano positioning stage employing active-passive hybrid decoupling is experimentally studied. The flexible amplification mechanism integrating semi-compound bridge-type, lever, and steering configurations is proposed to achieve passive decoupling of the positioning stage. Active decoupling is accomplished through a Z-axis compensation mechanism. The experiment shows that the micro-nano positioning platform achieves the displacement of 85.7 μm × 86.6 μm × 8.2 μm, with X-axis and Y-axis coupling errors both below 0.4%. The Z-axis compensation mechanism effectively performs active compensation for loads up to 400 g. The developed positioning stage exhibits an enlarged workspace and enhanced anti-coupling performance compared to conventional designs.

Aiming at the problems of poor data opening and sharing ability and closed application ecology of substation integrated monitoring system, the open monitoring system of a substation based on platform + APP architecture is proposed, which realizes the decoupling of APP and the monitoring system vendor platform through the security reinforced container technology, unified data interaction technology, and data service-oriented middleware technology. The decoupling of APP and platform promotes the construction of an open and shared industrial ecosystem for substation-integrated monitoring systems, which in turn improves the level of substation intelligence.

Quantum memories with long storage times are key elements in long-distance quantum networks. The atomic frequency comb (AFC) memory in particular has shown great promise to fulfill this role, having demonstrated multimode capacity and spin-photon quantum correlations. However, the memory storage times have so-far been limited to about 1 ms, realized in a Eu3+ doped Y2SiO5 crystal at zero applied magnetic field. Motivated by studies showing increased spin coherence times under applied magnetic field, we developed an AFC spin-wave memory utilizing a weak 15 mT magnetic field in a specific direction that allows efficient optical and spin manipulation for AFC memory operations. With this field configuration the AFC spin-wave storage time increased to 40 ms using a simple spin-echo sequence. Furthermore, by applying dynamical decoupling techniques the spin-wave coherence time reaches 530 ms, a 300-fold increase with respect to previous AFC spin-wave storage experiments. This result paves the way towards long duration storage of quantum information in solid-state ensemble memories.

We establish a new decoupling inequality for curves in the spirit of earlier work of C. Demeter and the author which implies a new mean value theorem for certain exponential sums crucial to the Bombieri-Iwaniec method as developed further in the work of Huxley. In particular, this leads to an improved bound |ζ(12+it)|≪t13/84+ε|\\zeta (\\frac {1}{2} + it)| \\ll t^{13/84 + \\varepsilon } for the zeta function on the critical line.

In order to achieve the high-fidelity quantum control needed for a broad range of quantum information technologies, reducing the effects of noise and system inhomogeneities is an essential task. It is well known that a system can be decoupled from noise or made insensitive to inhomogeneous dephasing dynamically by using carefully designed pulse sequences based on square or delta-function waveforms such as Hahn spin echo or CPMG. However, such ideal pulses are often challenging to implement experimentally with high fidelity. Here, we uncover a new geometrical framework for visualizing all possible driving fields, which enables one to generate an unlimited number of smooth, experimentally feasible pulses that perform dynamical decoupling or dynamically corrected gates to arbitrarily high order. We demonstrate that this scheme can significantly enhance the fidelity of single-qubit operations in the presence of noise and when realistic limitations on pulse rise times and amplitudes are taken into account.

Qubit realized via photon polarization is a promising candidate for quantum information processing applications. Polarization decoherence mediated by a birefringent environment destroys the coherence in such qubits. Open-loop dynamical decoupling schemes are found to be good to control these kinds of decoherence. But simple open-loop control strategies are not effective to control higher-order decoherence. In the study, the effectiveness of concatenated dynamical decoupling schemes in controlling decoherence in photon polarization qubits was investigated. The propagation of different optical qubits in a birefringent channel environment was modeled, and numerical methods were used to compare the effectiveness of periodic dynamic decoupling (PDD) schemes with concatenated dynamical decoupling (CDD) schemes. The results showed that the CDD schemes were superior to PDD schemes in controlling the tested decoherence.

The goal of this work is to build a new family of stellar interior solutions in the anisotropic regime of pressure using the framework of gravitational decoupling via minimal geometric deformation. For such purpose, we use a generalization of the complexity factor of the well-known Wyman IIa ( n = 1) interior solution in order to close the Einstein’s Field Equations, as well we use the Wyman IIa, Tolman IV, and Heintzmann IIa and Durgapal IV models as seeds solutions. These models fulfill the fundamental physical acceptability conditions for the compactness factor of the system 4U 1820-30. Stability against convection and against collapse are also studied.

We consider the usage of dynamical decoupling in quantum metrology, where the joint evolution of system plus environment is described by a Hamiltonian. We show that by ultra-fast unitary control operations acting locally only on system qubits, noise can be eliminated while the desired evolution is only reduced by at most a constant factor, leading to Heisenberg scaling. We identify all kinds of noise where such an approach is applicable. Only noise that is generated by the Hamiltonian to be estimated itself cannot be altered. However, even for such parallel noise, one can achieve an improved scaling as compared to the standard quantum limit for any local noise by means of symmetrization. Our results are also applicable in other schemes based on dynamical decoupling, e.g. the generation of high-fidelity entangling gates.

For the application of parallel robots in the grinding industry, a parallel robot equipped with a constant force actuator that produces a constant force for grinding is designed. To study the characteristics of the parallel robot’s spatial positions and poses, the inverse solutions of the moving platform’s spatial positions and poses as well as the workspace where objects were ground were established by using DH parameters and geometric methods. The experimental results showed that the workspace where objects were ground was a cylinder with a cross section similar to a symmetric circular sector. To analyze the characteristics of the forces produced by the parallel robotic system, the dynamics equation was established via the Newton–Euler method to verify the rationality of the force decoupling design. Theoretical calculation combined with simulation and experimental analyses confirmed the viability of the theoretical analyses which lay a theoretical foundation for the design, manufacture and control of the parallel robotic system proposed in this paper.