A topological constraint model is developed to predict the compositional scaling of glass transition temperature ( T) in a metal-organic framework glass, aZIF-62 [Zn(ImbIm )]. A hierarchy of bond constraints is established using a combination of experimental results and molecular dynamic simulations with ReaxFF. The model can explain the topological origin of T as a function of the benzimidazolate concentration with an error of 3.5 K. The model is further extended to account for the effect of 5-methylbenzimidazolate, enabling calculation of a ternary diagram of T with a mixture of three organic ligands in an as-yet unsynthesized, hypothetical framework. We show that topological constraint theory is an effective tool for understanding the properties of metal-organic framework glasses.
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http://dx.doi.org/10.1021/acs.jpclett.8b03348 | DOI Listing |
Natl Sci Rev
January 2025
Institute for Advanced Study, Tsinghua University, Beijing 100084, China.
In closed systems, the celebrated Lieb-Schultz-Mattis (LSM) theorem states that a one-dimensional locally interacting half-integer spin chain with translation and spin rotation symmetries cannot have a non-degenerate gapped ground state. However, the applicability of this theorem is diminished when the system interacts with a bath and loses its energy conservation. In this letter, we propose that the LSM theorem can be revived in the entanglement Hamiltonian when the coupling to the bath renders the system short-range correlated.
View Article and Find Full Text PDFNat Commun
January 2025
MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
Structural brain organization in infancy is associated with later cognitive, behavioral, and educational outcomes. Due to practical limitations, such as technological advancements and data availability of fetal MRI, there is still much we do not know about the early emergence of topological organization. We combine the developing Human Connectome Project's large infant dataset with generative network modeling to simulate the emergence of network organization over early development.
View Article and Find Full Text PDFNeural Netw
January 2025
Chongqing Key Laboratory of Computational Intelligence, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China; College of Computer and Information Science, Chongqing Normal University, Chongqing, 401331, China. Electronic address:
The production of expressive molecular representations with scarce labeled data is challenging for AI-driven drug discovery. Mainstream studies often follow a pipeline that pre-trains a specific molecular encoder and then fine-tunes it. However, the significant challenges of these methods are (1) neglecting the propagation of diverse information within molecules and (2) the absence of knowledge and chemical constraints in the pre-training strategy.
View Article and Find Full Text PDFEntropy (Basel)
December 2024
Electronic Engineering Institute, National University of Defense Technology, Hefei 230037, China.
Correctly identifying influential nodes in a complex network and implementing targeted protection measures can significantly enhance the overall security of the network. Currently, indicators such as degree centrality, closeness centrality, betweenness centrality, H-index, and K-shell are commonly used to measure node influence. Although these indicators can identify critical nodes to some extent, they often consider node attributes from a narrow perspective and have certain limitations.
View Article and Find Full Text PDFEntropy (Basel)
November 2024
Institute of Theoretical Physics, Wrocław University of Science and Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland.
We demonstrate that at the rim of the photon sphere of a black hole, the quantum statistics transition takes place in any multi-particle system of indistinguishable particles, which passes through this rim to the inside. The related local departure from Pauli exclusion principle restriction causes a decay of the internal structure of collective fermionic systems, including the collapse of Fermi spheres in compressed matter. The Fermi sphere decay is associated with the emission of electromagnetic radiation, taking away the energy and entropy of the falling matter without unitarity violation.
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