A Submillimeter Burst of S255IR~SMA1 - The Rise And Fall Of Its Luminosity

Temporal photometric variations at near infrared to submillimeter wavelengths have been found in low-mass young stellar objects. These phenomena are generally interpreted as accretion events of star-disk systems with varying accretion rates. There is growing evidence suggesting that similar luminosity flaring also occurs in high-mass star/cluster-forming regions. We report in this Letter the rise and fall of the 900 ${\mu}$m continuum emission and the newly found 349.1 GHz methanol maser emission in the massive star forming region S255IR~SMA1 observed with the Submillimeter Array and the Atacama Large Millimeter/submillimeter Array. The level of flux variation at a factor of $\sim$ 2 at the submillimeter band and the relatively short 2-year duration of this burst suggest that the event is probably similar to those milder and more frequent minor bursts seen in 3D numerical simulations.Comment: 8 pages, 4 figures, Accepted for publication in The Astrophysical Journal Lette

Preparation and Thermal Performance of Diatomite-Based Composite Phase Change Materials Wallboard

Two kinds of diatomite-based composite phase change materials (the phase change temperature was 35℃ and 42℃, respectively) were prepared by incorporating organic alcohol phase change materials into diatomite to form shape-stabilized composite PCMs. Then, diatomite-based phase change wallboards were fabricated, and the wallboards were attached to the exterior surface of the wall from a test small room to study the thermal performance. In this study, we investigated the effects on the wallboards location, the type of materials and the phase transition temperature on the thermal performance of the wallboards. It was found that comparing with the traditional polystyrene plastic insulation wallboard, the external surface temperature of the PCMs wallboards can be obviously lower than that of the traditional insulation wallboards due to thermal storage ability. But the thermal resistance of the PCMs wallboards was too small to reduce the indoor cooling load in summer comparing with the conventional polystyrene insulation wallboard. The suitable phase transition temperature for the PCMs wallboard was dependent on the orientation of the wall. At the same time, the optimal phase transition temperature is not just dependent on the outdoor meteorological conditions, but also relevant to the applied scenarios

Multipotent vascular stem cells contribute to neurovascular regeneration of peripheral nerve.

BackgroundNeurovascular unit restoration is crucial for nerve regeneration, especially in critical gaps of injured peripheral nerve. Multipotent vascular stem cells (MVSCs) harvested from an adult blood vessel are involved in vascular remodeling; however, the therapeutic benefit for nerve regeneration is not clear.MethodsMVSCs were isolated from rats expressing green fluorescence protein (GFP), expanded, mixed with Matrigel matrix, and loaded into the nerve conduits. A nerve autograft or a nerve conduit (with acellular matrigel or MVSCs in matrigel) was used to bridge a transected sciatic nerve (10-mm critical gap) in rats. The functional motor recovery and cell fate in the regenerated nerve were investigated to understand the therapeutic benefit.ResultsMVSCs expressed markers such as Sox 17 and Sox10 and could differentiate into neural cells in vitro. One month following MVSC transplantation, the compound muscle action potential (CMAP) significantly increased as compared to the acellular group. MVSCs facilitated the recruitment of Schwann cell to regenerated axons. The transplanted cells, traced by GFP, differentiated into perineurial cells around the bundles of regenerated myelinated axons. In addition, MVSCs enhanced tight junction formation as a part of the blood-nerve barrier (BNB). Furthermore, MVSCs differentiated into perivascular cells and enhanced microvessel formation within regenerated neurovascular bundles.ConclusionsIn rats with peripheral nerve injuries, the transplantation of MVSCs into the nerve conduits improved the recovery of neuromuscular function; MVSCs differentiated into perineural cells and perivascular cells and enhanced the formation of tight junctions in perineural BNB. This study demonstrates the in vivo therapeutic benefit of adult MVSCs for peripheral nerve regeneration and provides insight into the role of MVSCs in BNB regeneration

Strain-Induced Spin-Nematic State and Nematic Susceptibility Arising from 2×2 Fe Clusters in KFe_{0.8}Ag_{1.2}Te_{2}.

Spin nematics break spin-rotational symmetry while maintaining time-reversal symmetry, analogous to liquid crystal nematics that break spatial rotational symmetry while maintaining translational symmetry. Although several candidate spin nematics have been proposed, the identification and characterization of such a state remain challenging because the spin-nematic order parameter does not couple directly to experimental probes. KFe_{0.8}Ag_{1.2}Te_{2} (K_{5}Fe_{4}Ag_{6}Te_{10}, KFAT) is a local-moment magnet consisting of well-separated 2×2 Fe clusters, and in its ground state the clusters order magnetically, breaking both spin-rotational and time-reversal symmetries. Using uniform magnetic susceptibility and neutron scattering measurements, we find a small strain induces sizable spin anisotropy in the paramagnetic state of KFAT, manifestly breaking spin-rotational symmetry while retaining time-reversal symmetry, resulting in a strain-induced spin-nematic state in which the 2×2 clusters act as the spin analog of molecules in a liquid crystal nematic. The strain-induced spin anisotropy in KFAT allows us to probe its nematic susceptibility, revealing a divergentlike increase upon cooling, indicating the ordered ground state is driven by a spin-orbital entangled nematic order parameter

The Revelation of Foreign Carbon Emission Policies for Developing China Low-Carbon Economy

In present, developing the low-carbon economy is common recognized by the world. In order to achieve the aim of low-carbon economy, to reduce the carbon dioxide emissions is one of the most important measures. Nowadays, because of the large population, high energy intensity and the unreasonable energy structure based on fossil fuel, our country has faced an enormous pressure during the reducing carbon emissions process. Based on the current international applying carbon emission reduction proposals, we discussed the developed countries carbon emission reduction policies in detailed which includes the United States, Britain and Japan and etc. and in the meantime. Based on the above overseas developed countries experiences, the paper analyses  our country’s present situation of carbon emission reduction, finds the existing problems and put forward relevant recommendations. In brief, the research will provide some reference to build a low-carbon economy society of our country.Keywords:  low-carbon economy; CO2 emission; home and abroad carbon emission reduction policy; questions and measures Résumé:  A l'heure actuelle, le développement de l'économie à bas-carbone est généralement reconnu par le monde. Afin d'atteindre l'objectif de l'économie à bas-carbone, la réduction des émissions de dioxyde de carbone est l'une des mesures les plus importantes. De nos jours, en raison d'une population nombreuse, d'une intensité énergétique élevée et d'une structure énergétique déraisonnable basée sur les combustibles fossiles, notre pays a fait face à une pression énorme au cours du processus de réduction des émissions de carbone. Sur la base des propositions internationales de la réduction de l'émission de carbone actuellement appliquées, nous avons étudié les politiques de réduction des émissions de carboneles des pays développés en détail, qui comprend les États-Unis, la Grande-Bretagne, le Japon etc, et en même temps,  basé sur les expériences de ces pays développés ci-dessus, le document analyse la situation actuelle de notre pays en matière de la réduction des émissions de carbone, trouve des problèmes existants et propose des recommandations pertinentes. En bref, cette recherche fournira des références à la construction d'une société de l'économie bas-carbone dans notre pays.Mots-Clés:  économie à bas-carbone; émissions de CO2; politiques de la réduction de l'émission de carbone domestiques et étrangères; problèmes et mesure