A double template-assisted fabrication method for making surface patterns with tunable lattice geometries on a polymer surface is reported. This technique is based on a locally nonuniform strain produced in a double-templated polymer film that has a strong modulation in thickness. It can produce all 2D primitive Bravais lattices as well as chains on the surface of a polymer. The lattice parameters are controllable with nanoprecision by varying the direction and amount of the applied strain.
Abstract Two-dimensional (2D) van der Waals (vdW) heterostructures have attracted much attention due to their unique properties in photocatalysis, electronics, and energy storage. This work comprehensively analyzed the electronic properties and photocatalytic efficiency properties of 2D vdW MoS 2 /Hf 2 CO 2 heterostructure by first-principles calculations and molecular dynamics simulation. An ideal band gap of 1.44 eV was found for visible light absorption. Meanwhile, a high solar-to-hydrogen efficiency of 17.14% is obtained from the calculated band-edge positions, and a high power conversion efficiency of 13.84% is also confirmed by spectroscopy limited maximum efficiency simulation. We estimate the time scale for electron–hole transfer and recombination times using a combination of non-adiabatic molecular dynamics and time-dependent density functional theory. A suitable e-h recombination time of 1.86 ns and electron (hole) transfer time of 331 (978) fs are obtained in the 2D MoS 2 /Hf 2 CO 2 heterostructure, which is expected to ensure high photocatalytic efficiency. Therefore, the constructed MoS 2 /Hf 2 CO 2 heterostructures provide a new example for the prediction of high-performance nano optoelectronic devices.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Noncovalent interactions are quite important in biological structure-function relationships. To study the pairwise interaction of aromatic amino acids (phenylalanine, tyrosine, tryptophan) with anionic amino acids (aspartic and glutamic acids), small molecule mimics (benzene, phenol or indole interacting with formate) were used at the MP2 level of theory. The overall energy associated with an anion-quadrupole interaction is substantial (-9.5 kcal/mol for a benzene-formate planar dimer at van der Waals contact distance), indicating the electropositive ring edge of an aromatic group can interact with an anion. Deconvolution of the long-range coplanar interaction energy into fractional contributions from charge-quadrupole interactions, higher-order electrostatic interactions, and polarization terms was achieved. The charge-quadrupole term contributes between 30 to 45% of the total MP2 benzene-formate interaction; most of the rest of the interaction arises from polarization contributions. Additional studies of the Protein Data Bank (PDB Select) show that nearly planar aromatic-anionic amino acid pairs occur more often than expected from a random angular distribution, while axial aromatic-anionic pairs occur less often than expected; this demonstrates the biological relevance of the anion-quadrupole interaction. While water may mitigate the strength of these interactions, they may be numerous in a typical protein structure, so their cumulative effect could be substantial.
Abstract Lidar and visual data are affected heavily in adverse weather conditions due to sensing mechanisms, which bring potential safety hazards for vehicle navigation. Radar sensing is desirable to build a more robust navigation system. In this paper, a cross‐modality radar localisation on prior lidar maps is presented. Specifically, the proposed workflow consists of two parts: first, bird's‐eye‐view radar images are transferred to fake lidar images by training a generative adversarial network offline. Then with online radar scans, a Monte Carlo localisation framework is built to track the robot pose on lidar maps. The whole online localisation system only needs a rotating radar sensor and a pre‐built global lidar map. In the experimental section, the authors conduct an ablation study on image settings and test the proposed system on Oxford Radar Robot Car Dataset. The promising results show that the proposed localisation system could track the robot pose successfully, thus demonstrating the feasibility of radar style transfer for metric robot localisation on lidar maps.