Exotic Haldane Superfluid Phase of Soft-Core Bosons in Optical Lattices

We propose to realize an exotic Haldane superfluid (HSF) phase in an extended Bose-Hubbard model on the two-leg ladder (i.e., a two-species mixture of interacting bosons). The proposal is confirmed by means of large-scale quantum Monte Carlo simulations, with a significant part of the ground-state phase diagram being revealed. Most remarkably, the newly discovered HSF phase features both superfluidity and the non-local topological Haldane order. The effects induced by varying the number of legs are furthermore explored. Our results shed light on how topological superfluid emerges in bosonic systems.Comment: 5 pages, 6 figures; accepted for publication in Physical Review B (April 29, 2016

GeV Scale Asymmetric Dark Matter from Mirror Universe: Direct Detection and LHC Signatures

Mirror universe is a fundamental way to restore parity symmetry in weak interactions. It naturally provides the lightest mirror nucleon as a unique GeV-scale asymmetric dark matter particle candidate. We conjecture that the mirror parity is respected by the fundamental interaction Lagrangian, and its possible soft breaking arises only from non-interaction terms in the gauge-singlet sector. We realize the spontaneous mirror parity violation by minimizing the vacuum Higgs potential, and derive the corresponding Higgs spectrum. We demonstrate that the common origin of CP violation in the visible and mirror neutrino seesaws can generate the right amount of matter and mirror dark matter via leptogenesis. We analyze the direct detections of GeV-scale mirror dark matter by TEXONO and CDEX experiments. We further study the predicted distinctive Higgs signatures at the LHC.Comment: 16pp. Plenary talk presented by HJH at the International Symposium on Cosmology and Particle Astrophysics (CosPA2011). To appear in the conference proceedings of IJMP. Minor refinement

Flux-lattice melting in LaO1−x_{1-x}Fx_{x}FeAs: first-principles prediction

We report the theoretical study of the flux-lattice melting in the novel iron-based superconductor $LaO_{0.9}F_{0.1}FeAs$ and $LaO_{0.925}F_{0.075}FeAs$. Using the Hypernetted-Chain closure and an efficient algorithm, we calculate the two-dimensional one-component plasma pair distribution functions, static structure factors and direct correlation functions at various temperatures. The Hansen-Verlet freezing criterion is shown to be valid for vortex-liquid freezing in type-II superconductors. Flux-lattice meting lines for $LaO_{0.9}F_{0.1}FeAs$ and $LaO_{0.925}F_{0.075}FeAs$ are predicted through the combination of the density functional theory and the mean-field substrate approach.Comment: 5 pages, 4 figures, to appear in Phys. Rev.

Analytical Study of the Responses of Bottom Panels under Slamming Loads and Steel/Composite Hybrid Slamming Test Boat

This dissertation consists of three parts - analytical modeling of slamming on a simplified bottom structure (Papers 1-2), manufacturing of sandwich panels and installing them on the Numerette high-speed offshore research boat, and experimental evaluation of slamming using the Numerette (Paper 3). In the first part, the responses of boat hull bottom panels under slamming loads are studied analytically using a linear elastic Euler-Bernoulli beam as a representation of the cross section of a bottom panel. The slamming pressure is modeled as a high-intensity peak followed by a lower constant pressure, traveling at constant speed along the beam. The problem is solved using a Fourier sine integral transformation in space and a Laplace-Carson integral transformation in time. The response of the beam is solved analytically. Deflection and bending moment as functions of time and position for different slamming speeds, bending stiffnesses, etc. are given. The response during both the initial structural inertia phase and the subsequent free vibration phase are studied and compared. In particular the effect of slamming load traveling speed on structural response of the simplified bottom structure is investigated. It is found that rather large deflections and bending moments are encountered at certain speeds of the pressure, which suggests that bottom panels may benefit from tailoring their stiffness and mass properties such that loads are reduced. The importance of the high-intensity pressure peak often encountered during slamming is also studied. In the second part some analysis of the structure plus manufacturing of sandwich panels for the Numerette craft is outlined. In the third part, experimentally obtained data from slamming on the bottom of the Numerette is studied. By combining traditional steel with modern composite materials, a creative steel/composite hybrid ship structure concept is developed and adopted in the design and manufacturing of the test boat. This slamming load test facility is also an attempt to shed some light on a new concept of building high-speed crafts with hybrid ship structures. With this new concept, the high-speed craft could be superior in certain aspects to traditional steel ship designs. The eventual goal is to develop the technology required to build a destroyer size ship using the steel/composite hybrid concept. Sea trials of the steel/composite hybrid boat were performed to evaluate the structural design of the steel/composite hybrid hull concept, as well as to investigate the response of bottom structures of high speed craft under slamming loads. A considerable amount of valuable data was collected with the onboard data acquisition system. Preliminary data analysis was accomplished. Typical strain and acceleration signals of bottom panels under real slamming loads were identified.Finally the conclusions and future work are briefly summarized in the last chapter of this dissertation

Bosonic Haldane insulator in the presence of local disorder: A quantum Monte Carlo study

The Haldane phase (HP) is a paradigmatic example of symmetry protected topological phase. We explore how the bosonic HP behaves in the presence of local disorder, employing quantum Monte Carlo simulations of an extended Bose-Hubbard model subject to uncorrelated, quenched disorders. We find that the HP is robust against a weak disorder and the non-local string order of HP exhibits a reentrant behavior. Besides, a direct transition between the HP and superfluid phase is uncovered. A significant part of the ground-state phase diagram is established for the model, unveiling the location of HP surrounded by Bose glass, charge density wave and superfluid phases. We also mention a possible experimental scheme with optical lattice emulator to realize the present findings.Comment: 6 pages, 5 figure

Research on Application of Cognitive-Driven Human-Computer Interaction

Human-computer interaction is an important research content of intelligent manufacturing human factor engineering. Natural human-computer interaction conforms to the cognition of users' habits and can efficiently process inaccurate information interaction, thus improving user experience and reducing cognitive load. Through the analysis of the information interaction process, user interaction experience cognition and human-computer interaction principles in the human-computer interaction system, a cognitive-driven human-computer interaction information transmission model is established. Investigate the main interaction modes in the current human-computer interaction system, and discuss its application status, technical requirements and problems. This paper discusses the analysis and evaluation methods of interaction modes in human-computer system from three levels of subjective evaluation, physiological measurement and mathematical method evaluation, so as to promote the understanding of inaccurate information to achieve the effect of interaction self-adaptation and guide the design and optimization of human-computer interaction system. According to the development status of human-computer interaction in intelligent environment, the research hotspots, problems and development trends of human-computer interaction are put forward

Small and Medium-Sized City: The Main Battle Field of the New Urbanization Construction

Small and medium-sized cities have played important roles in China’s new urbanization strategies. Small and medium-sized cities can not only help large cities avert over-concentration of population, but also avoid excessively decentralizing rural industrialization in small towns. To develop small and medium-sized cities, characteristic industries and vocational education are required so that people can get employed in the cities and become residents easily. City infrastructure and public services are necessary for urban residents. Public-Private Partnership may solve the problems of fund shortage that the local government is facing during the construction