successfully applied to the growth of AGNRs 11-13 and related structures [14][15][16] . Here, we describe the successful bottom-up synthesis of ZGNRs, which are fabricated by the surface-assisted colligation and cyclodehydrogenation of specifically designed precursor monomers including carbon groups that yield atomically precise zigzag edges. Using scanning tunnelling spectroscopy we prove the existence of edge-localized states with large energy splittings. We expect that the availability of ZGNRs will finally allow the characterization of their predicted spin-related properties such as spin confinement 17 and filtering 18,19 , and ultimately add the spin degree of freedom to graphene-based circuitry.To explore the fundamental electronic and magnetic properties related to zigzag edges and to realize specific carbon nanostructures for the controlled manipulation of their spin states,ZGNRs with atomically precise edges are required. For GNRs with armchair edges, it was demonstrated that atomic precision can indeed be achieved by a bottom-up approach based on the surface-assisted polymerization and subsequent cyclodehydrogenation of specifically designed oligophenylene precursor monomers 11 . The on-surface synthesis has been applied by many groups to fabricate a number of different AGNR structures [11][12][13] , N-doped AGNRs 14,15 as well as AGNR heterostructures 15,16 . It is, however, not directly suited forZGNRs since polymerization of monomers via aryl-aryl coupling does not take place along the zigzag but along the armchair direction (Fig. 1a). In addition, dehydrogenative cyclization of phenyl subgroups is not sufficient to form pure zigzag edges, thus calling for a totally new chemical design. Thereby, additional carbon functions must be placed at the edges of the monomers to complete the tiling toolbox needed for the bottom-up fabrication of arbitrary GNR structures.Here, we report a bottom-up fabrication approach to ZGNRs. In our unique protocol, surfaceassisted polymerization and subsequent cyclization of suitably designed molecular precursors carrying the full structural information of the final ZGNR afford atomic precision with respect to ribbon width and edge morphology. The groundbreaking idea depends upon the choice of a unique U-shaped monomer as 1 shown in Fig. 1b. With two halogen functions for thermally induced aryl-aryl-coupling at the R 1 positions, it allows the polymerization toward a snake-like polymer. It is the beauty of this design that additional phenyl groups at the R 2 position fill the holes in the interior of the undulating polymer. The crucial precursor is monomer 1a which carries two additional methyl groups. In such a case, apart from the 3 polymerization and planarization, an oxidative ring closure including the methyl groups is expected which would then establish two new six-membered rings together with the zigzag edge structure. To our delight, this concept could indeed be synthetically realized under reaction monitoring and structure proof by scanning tunneling microscopy (S...

With the application of Internet of Things and services to manufacturing, the fourth stage of industrialization, referred to as Industrie 4.0, is believed to be approaching. For Industrie 4.0 to come true, it is essential to implement the horizontal integration of inter-corporation value network, the end-to-end integration of engineering value chain, and the vertical integration of factory inside. In this paper, we focus on the vertical integration to implement flexible and reconfigurable smart factory. We first propose a brief framework that incorporates industrial wireless networks, cloud, and fixed or mobile terminals with smart artifacts such as machines, products, and conveyors. Then, we elaborate the operational mechanism from the perspective of control engineering, that is, the smart artifacts form a self-organized system which is assisted with the feedback and coordination blocks that are implemented on the cloud and based on the big data analytics. In addition, we outline the main technical features and beneficial outcomes and present a detailed design scheme. We conclude that the smart factory of Industrie 4.0 is achievable by extensively applying the existing enabling technologies while actively coping with the technical challenges.

Boundaries between distinct topological phases of matter support robust, yet exotic quantum states such as spin-momentum locked transport channels or Majorana fermions. The idea of using such states in spintronic devices or as qubits in quantum information technology is a strong driver of current research in condensed matter physics. The topological properties of quantum states have helped to explain the conductivity of doped trans-polyacetylene in terms of dispersionless soliton states. In their seminal paper, Su, Schrieffer and Heeger (SSH) described these exotic quantum states using a one-dimensional tight-binding model. Because the SSH model describes chiral topological insulators, charge fractionalization and spin-charge separation in one dimension, numerous efforts have been made to realize the SSH Hamiltonian in cold-atom, photonic and acoustic experimental configurations. It is, however, desirable to rationally engineer topological electronic phases into stable and processable materials to exploit the corresponding quantum states. Here we present a flexible strategy based on atomically precise graphene nanoribbons to design robust nanomaterials exhibiting the valence electronic structures described by the SSH Hamiltonian. We demonstrate the controlled periodic coupling of topological boundary states at junctions of graphene nanoribbons with armchair edges to create quasi-one-dimensional trivial and non-trivial electronic quantum phases. This strategy has the potential to tune the bandwidth of the topological electronic bands close to the energy scale of proximity-induced spin-orbit coupling or superconductivity, and may allow the realization of Kitaev-like Hamiltonians and Majorana-type end states.

The proliferation of cyber-physical systems introduces the fourth stage of industrialization, commonly known as Industry 4.0. The vertical integration of various components inside a factory to implement a flexible and reconfigurable manufacturing system, i.e., smart factory, is one of the key features of Industry 4.0. In this paper, we present a smart factory framework that incorporates industrial network, cloud, and supervisory control terminals with smart shop-floor objects such as machines, conveyers, and products. Then, we provide a classification of the smart objects into various types of agents and define a coordinator in the cloud. The autonomous decision and distributed cooperation between agents lead to high flexibility. Moreover, this kind of self-organized system leverages the feedback and coordination by the central coordinator in order to achieve high efficiency. Thus, the smart factory is characterized by a self-organized multi-agent system assisted with big data based feedback and coordination. Based on this model, we propose an intelligent negotiation mechanism for agents to cooperate with each other. Furthermore, the study illustrates that complementary strategies can be designed to prevent deadlocks by improving the agents' decision making and the coordinator's behavior. The simulation results assess the effectiveness of the proposed negotiation mechanism and deadlock prevention strategies.