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Tricyclo[4.3.1.03,7]decane is also known as isotwistane, which is commonly found in the structures of natural products. This work accomplished the synthesis of this scaffold through 7 steps, including pivotal Diels–Alder and Conia-ene reactions. The optimized molecular crystal structure data obtained from density functional theory (DFT) calculation aligned with the actual values from X-ray diffraction. Building upon this, molecular electrostatic potential (MEP) and frontier molecular orbital (FMOs) analyses were performed, elucidating the relevant physicochemical properties of this framework for the first time. [ABSTRACT FROM AUTHOR]

To search for half-metallic materials for spintronic applications, instead of using an expensive trial-and-error experimental scheme, it is more efficient to use first-principles calculations to design materials first, and then grow them. In particular, using a priori information of the structural stability and the effect of the spin--orbit interaction (SOI) enables experimentalists to focus on favorable properties that make growing half-metals easier. We suggest that using acoustic phonon spectra is the best way to address the stability of promising half-metallic materials. Additionally, by carrying out accurate first-principles calculations, we propose two criteria for neglecting the SOI so the half-metallicity persists. Based on the mechanical stability and the negligible SOI, we identified two half-metals, β-LiCrAs and β-LiMnSi, as promising half-Heusler alloys worth growing. [ABSTRACT FROM AUTHOR]

We investigate the electronic properties and valley physics of Janus monolayer WSSe on a CrI3 substrate layer based on first-principles calculations. It is shown that the K and K0 valley degeneracy can be lifted which leads to valley polarization (VP) in the WSSe due to the magnetic proximity coupling to a magnetic substrate. The magnitude of VP is highly sensitive to the interfacial electronic properties and can be tuned by varying the stacking configurations of the heterostructure. Interestingly, the direction of VP can be altered by manipulating the layer alignment without reversing the magnetism orientation of the magnetic substrate CrI3. We suggest that the hybridization between the bands of WSSe and the substrate plays an important role. Meanwhile, the charge distributions have been mapped out to uncover the microscopic origin of the direction variable VP. In addition, large VP can be achieved by adjusting the interlayer spacing. Our investigations may have potential applications in the design of valleytronic devices. [ABSTRACT FROM AUTHOR]

This study proposes the use of generative adversarial networks (GANs) to solve two crucial problems in the unmanned ship navigation: insufficient training data for neural networks and convergence of optimal actions under discrete conditions. To achieve smart collision avoidance of unmanned ships in various sea environments, first, this study proposes a collision avoidance decision model based on a deep reinforcement learning method. Then, it utilizes GANs to generate enough realistic image training sets to train the decision model. According to generative network learning, the conditional probability distribution of ship maneuvers is learnt (action units). Subsequently, the decision system can select a reasonable action to avoid the obstacles due to the discrete responses of the generated model to different actions and achieve the effect of intelligent collision avoidance. The experimental results showed that the generated target ship image set can be used as the training set of decision neural networks. Further, a theoretical reference to optimize the optimal convergence of discrete actions is provided. [ABSTRACT FROM AUTHOR]

We theoretically studied the magnetostatic excitation in self-similar antiferromagnetic(AF)/nonmagnetic(NM) multilayers, where the AF and NM layers were arranged in a Thue-Morse sequence. The dispersion relation of magnetostatic spin waves and the precession amplitude of the total magnetization were achieved. It is shown that the distribution of eigenfrequencies possesses two bands of dual structures and each subband presents a hierarchical feature. The states in the finite system can be categorized to three types: critical states in the subband, extended states in the band, and localized surface states in the gaps. The multiformity in frequency spectra leads to the tunable magnetostatic wave, which may have potential applications in designing devices of magnetostatic waves for microwave communications. [ABSTRACT FROM AUTHOR]

The effect of Cr doping on the charge-ordered (CO) state of the bilayered manganite LaSr2Mn2O is investigated by electronic transport and magnetic property measurements. With Cr doping, the metal-insulator transition disappears and the temperature dependence of resistivity ρ(T) exhibits semiconducting behavior. Both the antiferromagnetic transition temperature TN and the CO temperature TCO shift to lower temperature and the cluster glass state appears with increasing Cr doping level. The increase of resistivity and the slight change in the magnetization with increasing Cr content may be related to the combined effect of the partial destruction of the Mn-O-Mn interaction network within the ferromagnetic (FM) layers of an A-type antiferromagnet and the appearance of Cr3+-O-Mn3+ FM interaction. Additionally, the introduction of the random Coulomb potential caused by the substitution of Cr3+ for Mn3+ is also a source of increased resistivity. Both, the different effects of Mn-site doping on the CO state between the perovskite and layered manganites and the different effects of Co doping and Cr doping in the Mn site in layered manganites on the CO state are discussed. [ABSTRACT FROM AUTHOR]

The effect of Cr doping on the charge-ordered (CO) state of the bilayered manganite LaSr2Mn2O is investigated by electronic transport and magnetic property measurements. With Cr doping, the metal-insulator transition disappears and the temperature dependence of resistivity ρ(T) exhibits semiconducting behavior. Both the antiferromagnetic transition temperature TN and the CO temperature TCO shift to lower temperature and the cluster glass state appears with increasing Cr doping level. The increase of resistivity and the slight change in the magnetization with increasing Cr content may be related to the combined effect of the partial destruction of the Mn-O-Mn interaction network within the ferromagnetic (FM) layers of an A-type antiferromagnet and the appearance of Cr3+-O-Mn3+ FM interaction. Additionally, the introduction of the random Coulomb potential caused by the substitution of Cr3+ for Mn3+ is also a source of increased resistivity. Both, the different effects of Mn-site doping on the CO state between the perovskite and layered manganites and the different effects of Co doping and Cr doping in the Mn site in layered manganites on the CO state are discussed. [ABSTRACT FROM AUTHOR]

We theoretically investigate spin-dependent transport in quasiperiodic cascade junctions of a ferromagnetic metal (FM) and semiconductor (SC), where FM and SC are arranged in the Fibonacci sequence. It is shown that spin-up and spin-down electrons possess different bandgap structures against the Rashba spin-orbit wave vector. The spin-dependent bandgap structure has the hierarchical characteristic and present self-similarity. Due to the quasiperiodicity, multiple resonant transmissions for spin-up or spin-down electrons can be observed within the bandgap; thereafter, spin polarization has multiple reversals. And it is also found that the electrical conductance can come from one kind of spin electrons around the resonant wave vector. These investigations may provide a unique way to design the devices such as spin filters and spin switches. [ABSTRACT FROM AUTHOR]

We investigate spin-dependent transport in ferromagnetic metal (FM)/semiconductor (SC) cascade junctions, which can be denoted as (FM/SC)n/FM. Here, n is the repeated number of FM/SC junction. In the Landauer framework of ballistic transport, we have calculated the spin-dependent transmission and the spin polarization in these cascade junctions. It is shown that spin-up and spin-down electrons possess different bandgap structures against the Rashba spin-orbit wave vector. As a result, high spin polarization can be achieved. Besides, resonant transmission for spin-up or spin-down electrons can be observed within the bandgap when we intentionally change the magnetization of FM in the center of the cascade junctions. Around resonant wave vector, spin polarization will be reversed. Our investigations may have potential applications in spin filters and spin switches. [ABSTRACT FROM AUTHOR]

We investigate magnetic-flux-induced persistent currents in one-dimensional symmetric-polymer (SP) mesoscopic ring, where a defect cluster is embedded into two periodic clusters and the whole cluster possesses mirror symmetry. Under tight-binding approximation, the flux-dependent energy spectra, electronic wave functions, and persistent currents are obtained. It is shown that the energy spectra form band structure and the defect modes appear in the band gap. The persistent current (PC) depends on the magnetic flux, the site energy, and the Fermi level. Particularly, by changing the Fermi level, the SP ring presents metallic and insulative features alternately. Our investigations provide a possible model to explain the anomalously large PC observed in some experiments and contribute to the potential application in quantum-switch devices. [ABSTRACT FROM AUTHOR]

The aim of this study is to construct an unmanned ship swarms monitoring model to improve autonomous decision-making efficiency and safety performance of unmanned ship navigation. A framework is proposed to determine the relationship between on-board decision-making and shore side monitoring, the process of ship data detection, tracking, analysis and loss, and the application of decision-making algorithm, to discuss the different risk responses of specific unmanned ship types under various latent hazard environments, particularly in terms of precise conversion timing in switching over to remote control and full manual monitoring, to ensure safe navigation when the capability of automatic risk response inadequate. This framework makes it easier to train data and the adjustment for machine learning based on Bayesian risk prediction. It can be concluded that the automation level can be increased and the workload of shore-based seafarers can be reduced easily. [ABSTRACT FROM AUTHOR]