Artificial ices enable the study of geometrical frustration by design and through direct observation. However, it has proven difficult to achieve tailored long-range ordering of their diverse configurations, limiting both fundamental and applied research directions. We designed an artificial spin structure that produces a magnetic charge ice with tunable long-range ordering of eight different configurations. We also developed a technique to precisely manipulate the local magnetic charge states and demonstrate write-read-erase multifunctionality at room temperature. This globally reconfigurable and locally writable magnetic charge ice could provide a setting for designing magnetic monopole defects, tailoring magnonics, and controlling the properties of other two-dimensional materials.

Abstract. -We present point-contact spectroscopy data for junctions between a normal metal and the newly discovered F-doped superconductor LaO0.9F 0.1−δ FeAs (F-LaOFeAs). A zero-bias conductance peak was observed and its shape and magnitude suggests the presence of Andreev bound states at the surface of F-LaOFeAs, which provides a possible evidence of an unconventional pairing symmetry with a nodal gap function. The maximum gap value ∆0 ≈ 3.9 ± 0.7meV was determined from the measured spectra, in good agreement with the recent experiments on specific heat and lower critical field.

By substituting the Fe with the 4d-and 5d-transition metals Rh, Ir, and Pd in SrFe 2 As 2 , we have successfully synthesized a series of superconductors SrFe 2−x M x As 2 ͑M = Rh, Ir, and Pd͒ and explored the phase diagrams of them. The systematic evolution of the lattice constants indicated that part of the Fe ions were successfully replaced by the transition metals Rh, Ir, and Pd. By increasing the doping content of Rh, Ir, and Pd, the antiferromagnetic ͑AF͒ state of the parent phase is suppressed progressively and superconductivity is induced. The general phase diagrams were obtained and found to be similar to the case of doping Co and Ni to the Fe sites. However, the detailed structure of the phase diagram, in terms of how fast to suppress the antiferromagnetic order and induce the superconductivity, varies from one kind of doped element to another. Regarding the close values of the maximum superconducting transition temperatures in doping Co, Rh, and Ir which locate actually in the same column in the periodic table of elements but have very different masses, we argue that the superconductivity is intimately related to the suppression of the AF order, rather than the electron-phonon coupling.

6Paraffin has a great potential as the phase change material (PCM) to be applied in many energy-related 7 applications, such as thermal energy storage and thermal management, due to its appropriate phase change 8 temperature and large latent heat. The heat transfer characteristics during phase change of paraffin play a 9 very important role in determining the thermo-fluidic performance of the systems. However, the drawback 10 of small thermal conductivity of PCM hampers its application. In the present study, the composite PCM 11 was fabricated by using copper foam to enhance the thermal conductivity of paraffin, and an experimental 12 setup was built to study the phase change heat transfer characteristics of composite PCM. The evolvement 13 of solid-liquid interface and temperature variation during the melting process were experimentally 14 investigated, and the experimental results were compared with the numerical results obtained by the 15 two-temperature energy model. It was indicated that there was a quite large temperature difference between 16 the ligament of copper foam and paraffin, which was due to the thermal non-equilibrium effect in heat 17 transfer between the paraffin and copper foam. Good agreement between the experimental and numerical 18 results showed that the heat transfer characteristics could be well depicted by the two-temperature energy 19 model, which can be further used to depict the heat transfer in thermal energy storage or temperature 20 management using composite PCM. 21 22