Optimization and resilience of complex supply-demand networks

Acknowledgments This work was supported by NSF under Grant No. 1441352. SPZ and ZGH were supported by NSF of China under Grants No. 11135001 and No. 11275003. ZGH thanks Prof Liang Huang and Xin-Jian Xu for helpful discussions.Peer reviewedPublisher PD

Bis(μ-carboxyl­atoethyl­phospho­nato)bis­[aqua­(2,2′-bipyridine)manganese(II)]

The title compound, [Mn2(HO3PCH2CH2COO)2(C8H8N2)2(H2O)2], was obtained by hydro­thermal synthesis. The manganese(II) ions are six-coordinate and are linked by two 2-carboxy­ethyl­phospho­nate ligands, forming a centrosymmetric dimer. The Mn ions adopts a distorted octahedral coordination geometry. The dimers are further linked by O—H⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid distance 4.2754 (4) Å]

Anisotropic and high thermal conductivity in monolayer quasi-hexagonal fullerene: A comparative study against bulk phase fullerene

Recently a novel two-dimensional (2D) C$_{60}$ based crystal called quasi-hexagonal-phase fullerene (QHPF) has been fabricated and demonstrated to be a promising candidate for 2D electronic devices [Hou et al. Nature 606, 507-510 (2022)]. We construct an accurate and transferable machine-learned potential to study heat transport and related properties of this material, with a comparison to the face-centered-cubic bulk-phase fullerene (BPF). Using the homogeneous nonequilibrium molecular dynamics and the related spectral decomposition methods, we show that the thermal conductivity in QHPF is anisotropic, which is 137(7) W/mK at 300 K in the direction parallel to the cycloaddition bonds and 102(3) W/mK in the perpendicular in-plane direction. By contrast, the thermal conductivity in BPF is isotropic and is only 0.45(5) W/mK. We show that the inter-molecular covalent bonding in QHPF plays a crucial role in enhancing the thermal conductivity in QHPF as compared to that in BPF. The heat transport properties as characterized in this work will be useful for the application of QHPF as novel 2D electronic devices.Comment: 11 pages, 12 figure

Ionic effect on combing of single DNA molecules and observation of their force-induced melting by fluorescence microscopy

Molecular combing is a powerful and simple method for aligning DNA molecules onto a surface. Using this technique combined with fluorescence microscopy, we observed that the length of lambda-DNA molecules was extended to about 1.6 times their contour length (unextended length, 16.2 micrometers) by the combing method on hydrophobic polymethylmetacrylate (PMMA) coated surfaces. The effects of sodium and magnesium ions and pH of the DNA solution were investigated. Interestingly, we observed force-induced melting of single DNA molecules.Comment: 12 page

3,9-Dichloro-2,4,8,10-tetra­oxa-3,9-di­phosphaspiro­[5.5]undecane-3,9-dione

In the title compound, C5H8Cl2O6P2, the two six-membered rings display chair conformations. The P=O bond distances are 1.444 (2) and 1.446 (2) Å. Weak inter­molecular C—H⋯O hydrogen bonds are present in the crystal structure