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One of the major breakthroughs associated with multiferroicity in recent years is the discovery of ferroelectricity generated by specific magnetic structures in some magnetic insulating oxides such as rare-earth manganites RMnO3 and RMn2O5. An unresolved issue is the small electric polarization. Relatively large electric polarization and strong magnetoelectric coupling have been found in those manganites of double magnetic ions: magnetic rare-earth R ion and Mn ion, due to the strong R-Mn (4f-3d) interactions. DyMn2O5 is a representative example. We unveil in this work the ferrielectric nature of DyMn2O5, in which the two ferroelectric sublattices with opposite electric polarizations constitute the ferrielectric state. One sublattice has its polarization generated by the symmetric exchange striction from the Mn-Mn interactions, while the polarization of the other sublattice is attributed to the symmetric exchange striction from the Dy-Mn interactions. We present detailed measurements on the electric polarization as a function of temperature, magnetic field, and measuring paths. The present experiments may be helpful for clarifying the puzzling issues on the multiferroicity in DyMn2O5 and other RMn2O5 multiferroics.

Anisotropic modification on nanodiscs could trigger huge differences in their endocytosis mode and following behaviors. In article number https://doi.org/10.1002/adfm.201700406 Zhifei Dai, Qiang Zhang, and co‐workers design analyze the cellular uptake of nanoparticulates differing in anisotropy of shape and ligand modification. This anisotropy‐based approach is promising for manipulating the biointeraction mode of nanomaterials and its outcome.

We integrate the orbital solutions of the planets orbiting 55 Cnc. In the simulations, we find that not only three resonant arguments θ 1 = λ 1 − 3λ 2 + 2ω 1 , θ 2 = λ 1 − 3λ 2 + 2ω 2 and θ 3 = λ 1 − 3λ 2 + (ω 1 +ω 2 ) librate respectively, but the relative apsidal longitudes ∆ω also librates about 250 • for millions of years. The results imply the existence of the 3:1 resonance and the apsidal resonance for the studied system. We emphasize that the mean motion resonance and apsidal locking can act as two important mechanisms of stabilizing the system. In addition, we further investigate the secular dynamics of this system by comparing the numerical results with those given by Laplace-Lagrange secular theory.

Summary Shale gas has changed the energy equation around the world, and its impact has been especially profound in the United States. It is now generally agreed that the fabric of shale systems comprises primarily organic matter, inorganic material, and natural fractures. However, the underlying flow mechanisms through these multiporosity and multipermeability systems are poorly understood. For instance, debate still exists about the predominant transport mechanism (diffusion, convection, and desorption), as well as the flow interactions between organic matter, inorganic matter, and fractures. Furthermore, balancing the computational burden of precisely modeling the gas transport through the pores vs. running full reservoir scale simulation is also contested. To that end, commercial reservoir simulators are developing new shale gas options, but some, for expediency, rely on simplification of existing data structures and/or flow mechanisms. We present here the development of a comprehensive multimechanistic (desorption, diffusion, and convection), multiporosity (organic materials, inorganic materials, and fractures), and multipermeability model that uses experimentally determined shale organic and inorganic material properties to predict shale gas reservoir performance. Our multimechanistic model takes into account gas transport caused by both pressure driven convection and concentration driven diffusion. The model accounts for all the important processes occurring in shale systems, including desorption of multicomponent gas from the organics' surface, multimechanistic organic/inorganic material mass transfer, multimechanistic inorganic material/fracture network mass transfer, and production from a hydraulically fractured wellbore. Our results show that a dual porosity, dual permeability (DPDP) model with Knudsen diffusion is generally adequate to model shale gas reservoir production. Adsorption can make significant contributions to original gas in place, but is not important to gas production because of adsorption equilibrium. By comparing triple porosity, dual permeability; DPDP; and single porosity, single permeability formulations under similar conditions, we show that Knudsen diffusion is a key mechanism and should not be ignored under low matrix pressure (Pematrix) cases, whereas molecular diffusion is negligible in shale dry gas production. We also guide the design of fractures by analyzing flow rate limiting steps. This work provides a basis for long term shale gas production analysis and also helps define value adding laboratory measurements.

As one of the recent advances of optics and photonics, plasmonics has enabled unprecedented optical designs. Having a vectorial configuration of surface plasmon field, metallic nanostructures offer efficient solutions in polarization control with a very limited sample thickness. Many compact polarization devices have been realized using such metallic nanostructures. However, in most of these devices, the functions were usually simple and limited to a few polarization states. Here, we demonstrated a plasmonic polarization generator that can reconfigure an input polarization to all types of polarization states simultaneously. The plasmonic polarization generator is based on the interference of the in-plane (longitudinal) field of the surface plasmons that gives rise to versatile near-field polarization states on a metal surface, which have seldom been considered in previous studies. With a well-designed nanohole array, the in-plane field of SPPs with proper polarization states and phases can be selectively scattered out to the desired light beams. A manifestation of eight focusing beams with well-routed polarizations was experimentally demonstrated. Our design offers a new route to achieve the full control of optical polarizations and possibly advance the development in photonic information processing. Keywords: near-field interference; phase modulation; plasmonics; polarization generator INTRODUCTIONOptical polarization is an important characteristic of light that enables transmission of information for signal processing in optical information technology by utilizing classical or quantum phenomena. Compared with conventional optical elements, plasmonic devices provide a more compact and efficient means to manipulate the polarization of light (e.g., plasmonic polarizers 1-5 , polarization rotators and converters 6-11 , polarization detectors 12 , etc.). Recently, plasmoninduced spin-orbital coupling has generated strong interest in the field of photonics [13][14][15][16][17] , primarily due to the possibility of polarization and phase modulation. In fact, the vectorial structure of the surface plasmon field gives rise to unique properties in the conversion of optical fields between propagating light and bounded surface plasmon polaritons (SPPs), where the polarization information of light can be reloaded by special SPPs in a controllable way [18][19][20][21][22] . However, most of these devices offer only limited functions in polarization control. To address the ever increasing requirements of information processing, a full polarization generator is one of the desired technologies.The limitations of polarization control would obviously be overcome with the development of a polarization converter that can convert all polarization states at the same time. However, developing such an all-states polarizer in a single device is quite a challenge. Here, we demonstrate such a plasmonic polarization generator that can generate, in principle, all types of polarizations and route them selectively to the appropriate beams in...

We numerically investigated the dynamical architecture of 47 UMa with the planetary configuration of the bestfit orbital solutions by Fischer and coworkers. We systematically studied the existence of Earth-like planets in the region 0:05 AU a 2:0 AU for 47 UMa with numerical simulations and also explored the packed planetary geometry and Trojan planets in the system. In the simulations, we found that ''hot Earths'' at 0:05 AU a < 0:4 AU can dynamically survive for at least 1 Myr. The Earth-like planets can eventually remain in the system for 10 Myr in areas involved in mean motion resonances (MMRs; e.g., 3:2 MMR) with the inner companion. Moreover, we showed that the 2:1 and 3:1 resonances are on the fringe of stability, while the 5:2 MMR is unstable. In addition, the 2:1 MMR marks out a remarkable boundary between chaotic and regular motions: inside, most of the orbits can survive, but outside, they are mostly lost in the orbital evolution. In a dynamical sense, the most likely candidates for habitable environments are Earth-like planets with orbits in the ranges 0:8 AU a < 1:0 AU and 1:0 AU < a < 1:30 AU (except the 5:2 MMR and several unstable cases) with relatively low eccentricities. The Trojan planets with low eccentricities and inclinations can secularly last at the triangular equilibrium points of the two massive planets. Hence, the 47 UMa planetary system may be a close analog to our solar system, bearing a similar dynamical structure. Subject headingg s: celestial mechanics -methods: n-body simulations -planetary systemsstars: individual (47 Ursae Majoris)