Constraining spacetime nonmetricity with neutron spin rotation in liquid 4He

General spacetime nonmetricity coupled to neutrons is studied. In this context, it is shown that certain nonmetricity components can generate a rotation of the neutron's spin. Available data on this effect obtained from slow-neutron propagation in liquid helium are used to constrain isotropic nonmetricity components at the level of GeV. These results represent the first limit on the nonmetricity parameter as well as the first measurement of nonmetricity inside matter.DOE/DE-SC0010120NSF/PHY-1614545IU Center for Spacetime SymmetriesNational Science Foundation of China/11605056Chinese Scholarship CouncilAlexander von Humboldt Foundatio

A Survey Study on Consumer Perception of Mobile- Commerce Applications

AbstractMobile commerce (m-commerce) can have an important influence on business and society in the future. Hence, m- commerce developers and practitioners must understand consumers’ perception of m-commerce applications in order to better design and deliver m-commerce service. This paper studied Chinese consumers’ perception of m-commerce applications by using the survey methodology. Firstly, 44 mobile applications were adopted on the basis of related study work, and then the web-based questionnaire was employed for obtaining online Chinese consumers’ importance ratings with regard to each mobile application. The survey result is helpful for both academics and practitioners to better design innovative and satisfying m-commerce applications

3′,6′-Bis(ethyl­amino)-2′,7′-dimethyl-2-{2-(E)-[(thio­phen-2-yl)methyl­idene­amino]­eth­yl}spiro­[isoindoline-1,9′-xanthen]-3-one methanol monosolvate

The title compound, C33H34N4O2S·CH3OH, was prepared as a spiro­lactam ring formation of rhodamine 6 G dye for comparison with a ring-opened form. The xanthene and spiro­lactam rings are approximately planar [r.m.s. deviations from planarity = 0.122 (3) and 0.072 (6) Å, respectively]. The dihedral angles formed by the spiro­lactam and thio­phene rings with the xanthene ring system are 89.7 (6) and 86.5 (2)°, respectively. The crystal structure features N—H⋯O and C—H⋯O hydrogen bonds

Galactic diffuse gamma-ray emission from GeV to PeV energies in light of up-to-date cosmic ray measurements

The diffuse gamma-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured by the Large High Altitude Air Shower Observatory (LHAASO). These observations will help tremendously in constraining the propagation and interaction of cosmic rays in the Milky Way. Additionally, new measurements of CR spectra reach a very high precision up to 100 TeV energies, revealing multiple spectral structures of various species. In this work, we confront the model prediction of the diffuse gamma-ray emission, based on up-to-date measurements of the local cosmic ray spectra and simplified propagation setup, with the measurements of diffuse gamma-rays. To better constrain the low-energy part of the model, we analyze the 14.6 years of Fermi-LAT data to extract the Galactic diffuse emission between 1 and 500 GeV from the same sky regions of LHAASO, after subtracting the contribution from known sources and the isotropic diffuse gamma-ray background. The joint Fermi-LAT and LHAASO spectra thus cover a very wide energy range from 1 GeV to 1 PeV with small gaps from 0.5 to 10 TeV. Compared with the prediction, we find that clear excesses between several GeV and ~60 TeV of the diffuse emission exist. Possible reasons to explain the excesses may include unresolved sources or more complicated propagation models. We illustrate that an exponential-cutoff-power-law component with an index of -2.40 and cutoff energy of ~30 TeV is able to account for such excesses

Aleurochiton orientalis Danzig, 1966 (Hemiptera: Aleyrodidae), newly recorded from China, with a key to puparia of all described Aleurochiton species

The genus Aleurochiton Tullgren (1907) is here newly recorded from China as A. orientalis Danzig (1966). It was collected from Acer mono Maxim (Sapindales: Aceraceae) in Shaanxi Province, but was originally described from the Russian Far East (Southern Primor’ye) by Danzig (1966). The puparial morphology of A. orientalis is here illustrated by line art, photomicrographs and scanning electron microscope (SEM) photographs. An identification key to the all five described Aleurochiton species is provided

Kinetically Controlled Synthesis of Cefaclor with Immobilized Penicillin Acylase in the Presence of Organic Cosolvents

Enzymatic syntheses of cefaclor with immobilized penicillin acylase in organic cosolvents under kinetic control were carried out. KcPGA from Kluyvera citrophila was selected as the best catalyst among the three species of immobilized penicillin acylase. Ethylene glycol, glycerol, methanol, ethyl estate and polyethyleneglycol (PEG) were selected accordingly and cefaclor syntheses were preformed respectively. Best results in terms of yield were obtained in ethylene glycol, with which further studies were investigated and the maximum yield was Y = 93.5 %. The optimal conditions were pH 6.5, temperature θ = 5 °C, 3 mol D-phenylglycine methyl ester (PGME) per mol 7-aminodesacetoxymehtyl-3-chlorocephalosporin acid (7ACCA) and x = 30 % ethylene glycol fraction. Under above mentioned conditions, the yield was Y = 91.1 %