Two-dimensional band structure in honeycomb metal-organic frameworks

Metal-organic frameworks (MOFs) are an important class of materials that present intriguing opportunities in the fields of sensing, gas storage, catalysis, and optoelectronics. Very recently, two-dimensional (2D) MOFs have been proposed as a flexible material platform for realizing exotic quantum phases including topological and anomalous quantum Hall insulators. Experimentally, direct synthesis of 2D MOFs has been essentially confined to metal substrates, where the interaction with the substrate masks the intrinsic electronic properties of the MOF. Here, we demonstrate synthesis of 2D honeycomb metal-organic frameworks on a weakly interacting epitaxial graphene substrate. Using low-temperature scanning tunneling microscopy (STM) and atomic force microscopy (AFM) complemented by density-functional theory (DFT) calculations, we show the formation of 2D band structure in the MOF decoupled from the substrate. These results open the experimental path towards MOF-based designer quantum materials with complex, engineered electronic structures

Quasinormal modes of a charged spherical black hole with scalar hair for scalar and Dirac perturbations

The quasinormal modes of charged and uncharged massive scalar fields and also of charged Dirac fields against the background of a charged spherical black hole endowed with a scalar hair have been investigated. Special emphasis has been given to the case where negative scalar charge dominates over the electric charge of the black hole which mimics an Einstein-Rosen bridge. Except for the complete monotonic behaviour of the damping (imaginary part of the quasinormal mode) against the charge of the black hole as opposed to the existence of a peak for the pure RN case, the qualitative behaviour does not appreciably change due to the presence of scalar hair.Comment: 12 pages; 24 figures. Accepted for publication in EPJ

A Supply Chain Coordination Mechanism for Common Items Subject to Failure in the Electronics, Defense, and Medical Industries

Improved production processes, particularly miniaturization, have led to the development and use of non-reworkable items subject to failure in modern production environments. Coordinating supply chains for these items requires cooperation between suppliers and buyers in order to balance ordering/setup and holding costs among system partners. In this paper, we first determine optimal inventory policies for both the supplier and buyer. We then apply the bisection method to develop a mechanism which uses a common replenishment time to coordinate a supply chain consisting of a single supplier and n buyers. By utilizing this optimization framework, we minimize total system-wide costs and derive the cost savings associated with our coordinated solution. Numerical examples are then provided for illustration

Mineralizing agents to manage early carious lesions. Part II: clinical application

The successful commercialization of mineralization technologies used for the primary and secondary prevention of early carious lesions provides several clinical options for the oral healthcare team using the minimum intervention oral care (MIOC) delivery framework. These new technologies are available in many different forms, with different properties, and can be used in a variety of clinical scenarios. This article is the second in a series providing a review on the clinical efficacy of new technologies and the products available, as well as clinical guidance for their use. CPD/Clinical Relevance: Clinicians should have an appreciation of the different mineralizing agents available, and their related guidelines