A dynamical model for liquid water

Anomalies in liquid water are attributed to librational/rotational motions, which depend cooperatively on H-bond structure within relatively stable oxygen groupings. The close relationships between small-ion hydration dynamics, spin-lattice and dielectric relaxation times, and shear viscosity are delineated. Within this context, the anomalous heat capacity of Oguni and Angell can be understood.     

Transient photopotentials at the cobalt-doped zinc oxide/electrolyte interface

The time evolution of the pulsed-laser-induced photopotentials of pure and cobalt-sensitized ZnO electrodes is analyzed after 365 and 640 nm excitations. This analysis, as a function of various parameters, enables a determination of the influence of Co²⁺ ions and excitation wavelength on the kinetics of electron-hole recombination and electron transfer at the interface to be made.     

Studies of various mechanisms of nuclear polarisation due to a resonant high-frequency field in radical reactions

Two different mechanisms of creation of nuclear polarisation in radical reaction products are studied by means of the high-frequency field influence on intermediate radical pairs (stimulated nuclear polarisation, SNP) and on intermediate short-lived radicals (dynamic nuclear polarisation, DNP). Criteria are formulated for distinguishing the contributions of DNP and SNP effects, and experimental demonstration of this possibility is presented for photoinduced reactions of quinones.     

1H NMR of probes oriented in stretched polyethylene

¹H NMR spectra of some small molecules oriented in stretched polyethylene rods have been recorded. The band splitting due to direct dipole-dipole couplings is obtained and the corresponding orientation parameters are shown as a function of the draw ratio of the polymer and the temperature. This method is compared to that of using liquid crystals as the orienting solvent.     

Observation by neutron incoherent inelastic spectroscopy of split higher harmonics of the ammonium ion librational mode in the cubic phase of NH4Br

This paper deals with high-resolution neutron scattering studies of the librational mode v₆ (0 → 1) and its higher overtones for NH⁺₄ in the ordered cubic phase of ammonium bromide, NH₄Br. Experiments were conducted on the time-focused crystal analyser (TFXA) spectrometer of the UK spallation neutron source, ISIS. v₆ (0 → 2) and v₆ (0 → 3) show distinct splittings of ≈ 5 meV, the results are compared with optical data and a theoretical model.     

Vacuum ultraviolet photon emission stimulated by H2+, N2+, and CO+ collisions with surfaces

Intravalence and Rydberg-type electronic transitions from excited projectile atoms and ions have been observed in the spectral range 30-200 nm as a result of 3 keV H⁺₂, N⁺₂, and CO⁺ bombardment of magnesium and graphite surfaces. Population of both types of excited states is consistent with an electron promotion mechanism resulting from close atomic encounters.     

A coupled states reactive scattering study of bending excited resonances in three-dimensional H + H2

Reaction probabilities from coupled states calculations on the Liu-Siegbahn-Truhlar-Horowitz surface for H+H₂ are calculated for the energy range 0.90–1.30 eV. Peaks in the vibrationally inelastic reaction probabilities near 1.10, 1.20 and 1.22–1.24 eV suggest that bending excited resonances labelled by the quantum numbers (11¹0), (12⁰0) and (12²0) exist.     

Joint Optimization of Control Strategy and Energy Consumption for Energy Harvesting WSAN

With the rapid development of wireless sensor technology, recent progress in wireless sensor and actuator networks (WSANs) with energy harvesting provide the possibility for various real-time applications. Meanwhile, extensive research activities are carried out in the fields of efficient energy allocation and control strategy design. However, the joint design considering physical plant control, energy harvesting, and consumption is rarely concerned in existing works. In this paper, in order to enhance system control stability and promote quality of service for the WSAN energy efficiency, a novel three-step joint optimization algorithm is proposed through control strategy and energy management analysis. First, the optimal sampling interval can be obtained based on energy harvesting, consumption, and remaining conditions. Then, the control gain for each sampling interval is derived by using a backward iteration. Finally, the optimal control strategy is determined as a linear function of the current plant states and previous control strategies. The application of UAV formation flight system demonstrates that better system performance and control stability can be achieved by the proposed joint optimization design for all poor, sufficient, and general energy harvesting scenarios.     

Optimal Energy-Storage Configuration for Microgrids Based on SOH Estimation and Deep Q-Network

Energy storage is an important adjustment method to improve the economy and reliability of a power system. Due to the complexity of the coupling relationship of elements such as the power source, load, and energy storage in the microgrid, there are problems of insufficient performance in terms of economic operation and efficient dispatching. In view of this, this paper proposes an energy storage configuration optimization model based on reinforcement learning and battery state of health assessment. Firstly, a quantitative assessment of battery health life loss based on deep learning was performed. Secondly, on the basis of considering comprehensive energy complementarity, a two-layer optimal configuration model was designed to optimize the capacity configuration and dispatch operation. Finally, the feasibility of the proposed method in microgrid energy storage planning and operation was verified by experimentation. By integrating reinforcement learning and traditional optimization methods, the proposed method did not rely on the accurate prediction of the power supply and load and can make decisions based only on the real-time information of the microgrid. In this paper, the advantages and disadvantages of the proposed method and existing methods were analyzed, and the results show that the proposed method can effectively improve the performance of dynamic planning for energy storage in microgrids.     

Synthesis and molecular structure of chlorotris(trimethylsilylmethyl)trimethylsilyl-methylidyne rhenium(VII)

The complex Re(CSiMe₃)(CH₂SiMe₃)₃Cl has been isolated as yellow crystals in low yield from the reaction of ReCl₄(THF)₂ with Me₃SiCH₂MgCl and characterised by X-ray crystallography. The molecule has a trigonal bipyramidal geometry with the alkylidyne and chlorine ligands axial.