Efficient spin-current injection in single-molecule magnet junctions

We study theoretically spin transport through a single-molecule magnet (SMM) in the sequential and cotunneling regimes, where the SMM is weakly coupled to one ferromagnetic and one normalmetallic leads. By a master-equation approach, it is found that the spin polarization injected from the ferromagnetic lead is amplified and highly polarized spin-current can be generated, due to the exchange coupling between the transport electron and the anisotropic spin of the SMM. Moreover, the spin-current polarization can be tuned by the gate or bias voltage, and thus an efficient spin injection device based on the SMM is proposed in molecular spintronics.Comment: 4 figure

Depth Completion with Multiple Balanced Bases and Confidence for Dense Monocular SLAM

Dense SLAM based on monocular cameras does indeed have immense application value in the field of AR/VR, especially when it is performed on a mobile device. In this paper, we propose a novel method that integrates a light-weight depth completion network into a sparse SLAM system using a multi-basis depth representation, so that dense mapping can be performed online even on a mobile phone. Specifically, we present a specifically optimized multi-basis depth completion network, called BBC-Net, tailored to the characteristics of traditional sparse SLAM systems. BBC-Net can predict multiple balanced bases and a confidence map from a monocular image with sparse points generated by off-the-shelf keypoint-based SLAM systems. The final depth is a linear combination of predicted depth bases that can be optimized by tuning the corresponding weights. To seamlessly incorporate the weights into traditional SLAM optimization and ensure efficiency and robustness, we design a set of depth weight factors, which makes our network a versatile plug-in module, facilitating easy integration into various existing sparse SLAM systems and significantly enhancing global depth consistency through bundle adjustment. To verify the portability of our method, we integrate BBC-Net into two representative SLAM systems. The experimental results on various datasets show that the proposed method achieves better performance in monocular dense mapping than the state-of-the-art methods. We provide an online demo running on a mobile phone, which verifies the efficiency and mapping quality of the proposed method in real-world scenarios

A robust tracking system for low frame rate video

Tracking in low frame rate (LFR) videos is one of the most important problems in the tracking literature. Most existing approaches treat LFR video tracking as an abrupt motion tracking problem. However, in LFR video tracking applications, LFR not only causes abrupt motions, but also large appearance changes of objects because the objects’ poses and the illumination may undergo large changes from one frame to the next. This adds extra difficulties to LFR video tracking. In this paper, we propose a robust and general tracking system for LFR videos. The tracking system consists of four major parts: dominant color-spatial based object representation, bin-ratio based similarity measure, annealed particle swarm optimization (PSO) based searching, and an integral image based parameter calculation. The first two parts are combined to provide a good solution to the appearance changes, and the abrupt motion is effectively captured by the annealed PSO based searching. Moreover, an integral image of model parameters is constructed, which provides a look-up table for parameters calculation. This greatly reduces the computational load. Experimental results demonstrate that the proposed tracking system can effectively tackle the difficulties caused by LFR

Understanding the Reactivity Difference of Isocyanate and Isothiocyanate toward a Ruthenium Silylene Hydride Complex

The detailed reaction mechanisms of the C=O hydrosilylation of isocyanate and the C=S bond cleavage of isothiocyanate mediated by the neutral ruthenium silylene hydride complex Cp{*}(CO)(H)Ru=Si(H){C(SiMe3)(3)} have been investigated with the aid of density functional theory calculations. Through the investigation, the difference in reactivity between isocyanate and isothiocyanate toward the ruthenium silylene hydride complex has been examined and discussed. The different bond strengths and if-accepting abilities of C=O and C=S and the different degrees of affinity of O and S toward the Si center in the silylene ligand contribute to the different reactivities of the isocyanate and isothiocyanate substrates observed experimentally

DFT Studies on the Palladium-Catalyzed Dearomatization Reaction between Chloromethylnaphthalene and the Cyclic Amine Morpholine

Density functional theory calculations have been performed to investigate the mechanisms of the Pd-catalyzed dearomatization reaction between chloromethylnaphthalene and the cyclic amine morpholine. The calculation results indicate that the reductive elimination leading to the formation of the dearomatic product takes place via an intramolecular C-N bond coupling between the para carbon of an eta(3)-exo-(naphthyl)methyl ligand and the nitrogen atom of the amide ligand. The free energy barrier is calculated to be only 13.1 kcal/mol, significantly lower than that (37.8 kcal/mol) through the eta(3)-endo-(naphthyl)methyl intermediate originally thought For comparison, various C-N coupling reaction pathways leading to the formation of dearomatic and aromatic products have also been examined