193 research outputs found
Bis[2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole-κN 3]diiodidocadmium
In the title complex, [CdI2(C16H12N2O2)2], the CdII atom is located on a twofold rotation axis and is four-coordinated by two N atoms from symmetry-related 2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole ligands and two I atoms in a distorted tetrahedral configuration. The benzimidazole rings in adjacent molecules are parallel, with an average interplanar distance of 3.486 Å. The I atom is disordered over two sites in a 0.85 (5):0.15 (5) ratio
Poly[[tetraaquabis(μ3-5-carboxybenzene-1,2,4-tricarboxylato)tricadmium] tetrahydrate]
There are three independent CdII ions in the title complex, {[Cd3(C10H3O8)2(H2O)4]·4H2O}n, one of which is coordinated by four O atoms from three 5-carboxybenzene-1,2,4-tricarboxylate ligands and by two water molecules in a distorted octahedral geometry. The second CdII ion is coordinated by five O atoms from four 5-carboxybenzene-1,2,4-tricarboxylate ligands and by one water molecule also in a distorted octahedral geometry while the third CdII ion is coordinated by five O atoms from three 5-carboxybenzene-1,2,4-tricarboxylate ligands and by one water molecule in a highly distorted octahedral geometry. The 5-carboxybenzene-1,2,4-tricarboxylate ligands bridge the CdII ions, resulting in the formation of a three-dimensional structure. Intra- and intermolecular O—H⋯O hydrogen bonds are present throughout the three-dimensional structure
QuadricsNet: Learning Concise Representation for Geometric Primitives in Point Clouds
This paper presents a novel framework to learn a concise geometric primitive
representation for 3D point clouds. Different from representing each type of
primitive individually, we focus on the challenging problem of how to achieve a
concise and uniform representation robustly. We employ quadrics to represent
diverse primitives with only 10 parameters and propose the first end-to-end
learning-based framework, namely QuadricsNet, to parse quadrics in point
clouds. The relationships between quadrics mathematical formulation and
geometric attributes, including the type, scale and pose, are insightfully
integrated for effective supervision of QuaidricsNet. Besides, a novel
pattern-comprehensive dataset with quadrics segments and objects is collected
for training and evaluation. Experiments demonstrate the effectiveness of our
concise representation and the robustness of QuadricsNet. Our code is available
at \url{https://github.com/MichaelWu99-lab/QuadricsNet}Comment: Submitted to ICRA 2024. 7 page
Bis[4-(2-hydroxybenzylideneamino)benzoato-κO 1]tetrakis(methanol-κO)cadmium
In the title mononuclear complex, [Cd(C14H10NO3)2(CH3OH)4], the Cd2+ cation is situated on an inversion centre. It exhibits a distorted octahedral coordination, defined by two carboxylate O atoms from two monodentate anions and by four O atoms from four methanol molecules. The crystal structure comprises intramolecular O—H⋯O and O—H⋯N, and intermolecular O—H⋯O hydrogen bonds. The latter help to construct a layered structure extending parallel to (100)
Diaquabis{1-[(1H-benzimidazol-2-yl)methyl]-1H-imidazole-κN 3}dichloridocadmium hexahydrate
In the title complex, [CdCl2(C11H10N4)2(H2O)2]·6H2O, the CdII atom is located on a twofold rotation axis and is coordinated by two N atoms from two 1-[(1H-benzimidazol-2-yl)methyl]-1H-imidazole ligands and two water O atoms in equatorial positions and by two Cl atoms in axial positions, leading to an elongated octahedral environment. The two coordinating and two of the lattice water molecules are also located on twofold rotation axes. In the crystal, complex molecules and solvent water molecules are linked through a complex intermolecular N—H⋯O, O—H⋯N, O—H⋯O and O—H⋯Cl hydrogen-bonding scheme into a three-dimensional network
Dichloridobis[2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole-κN 3]cadmium(II)
In the title complex, [CdCl2(C16H12N2O2)2], the CdII ion exhibits site symmetry 2. It shows a distorted tetrahedral coordination defined by two N atoms from symmetry-related 2-(2-furyl)-1-(2-furylmethyl)-1H-benzimidazole ligands and by two symmetry-related Cl atoms. Intramolecular C—H⋯O hydrogen bonds stabilize the molecular configuration. Adjacent molecules are linked through C—H⋯Cl hydrogen bonds into a network structure
2D-3D Pose Tracking with Multi-View Constraints
Camera localization in 3D LiDAR maps has gained increasing attention due to
its promising ability to handle complex scenarios, surpassing the limitations
of visual-only localization methods. However, existing methods mostly focus on
addressing the cross-modal gaps, estimating camera poses frame by frame without
considering the relationship between adjacent frames, which makes the pose
tracking unstable. To alleviate this, we propose to couple the 2D-3D
correspondences between adjacent frames using the 2D-2D feature matching,
establishing the multi-view geometrical constraints for simultaneously
estimating multiple camera poses. Specifically, we propose a new 2D-3D pose
tracking framework, which consists: a front-end hybrid flow estimation network
for consecutive frames and a back-end pose optimization module. We further
design a cross-modal consistency-based loss to incorporate the multi-view
constraints during the training and inference process. We evaluate our proposed
framework on the KITTI and Argoverse datasets. Experimental results demonstrate
its superior performance compared to existing frame-by-frame 2D-3D pose
tracking methods and state-of-the-art vision-only pose tracking algorithms.
More online pose tracking videos are available at
\url{https://youtu.be/yfBRdg7gw5M}Comment: This work has been submitted to the IEEE for possible publication.
Copyright may be transferred without notice, after which this version may no
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Azido{2-[bis(2-hydroxyethyl)amino]ethanolato-κ4 N,O,O′,O′′}cobalt(II)
In the title complex, [Co(C6H14NO3)(N3)] or [Co(teaH2)N3], the CoII atom resides in a trigonal–bipymidal O3N2 environment formed by three O atoms and one N atom from a simply deprotonated tetradentate triethanolamine ligand, and one N atom from an azide ligand. The O atoms define the equatorial plane whereas both N atoms are in axial positions. The mononuclear units are linked through O—H⋯O hydrogen-bonding interactions between the ethanol OH groups and the ethanolate O atom of a neighbouring complex into chains running parallel to [010]
Bis{1-[(1H-benzimidazol-1-yl)methyl-κN 3]-1H-1,2,3,4-tetrazole}silver(I) nitrate
In the title salt, [Ag(C9H8N6)2]NO3, the central AgI atom is linearly coordinated by the N atoms [171.97 (8)°] from two 1-[(benzimidazol-1-yl)methyl]-1H-1,2,3,4-tetrazole ligands. The benzimidazole rings in adjacent molecules are parallel with an average interplanar distance of 3.461 Å; adjacent molecules are linked through N—H⋯O hydrogen bonds into a linear chain along the b-axis direction
A new AgI complex based on 1-[(1H-benzimidazol-1-yl)methyl]-1H-1,2,4-triazole
In the title complex, bis{μ-1-[(1H-benzimidazol-1-yl)methyl]-1H-1,2,4-triazole}disilver(I) dinitrate, [Ag2(C10H9N5)2](NO3)2, the AgI ion is nearly linearly coordinated [N—Ag—N angle is 155.72 (14)°] by two 1-[(1H-benzimidazole-1-yl)methyl]-1H-1,2,4-triazole (bmt) ligands. In addition, two bmt ligands link two AgI ions, forming a dinuclear unit with an Ag⋯Ag distance of 5.0179 (15) Å. The whole complex is generated by an inversion centre. The dinuclear units and the NO3
− counter-ions are connected by N—H⋯O hydrogen bonds and weak Ag⋯O interactions [2.831 (5), 2.887 (5) and 2.908 (5) Å], leading to a three-dimensional structure
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