(1H-1,3-Benzimidazole-5,6-dicarboxylic acid)(5-carboxyl­ato-1H-1,3-benzimidazole-6-carboxylic acid)silver(I) monohydrate

The title compound, [Ag(C9H5N2O4)(C9H6N2O4)]·H2O, contains one independent Ag atom, a neutral 1H-benzimidazole-5,6-dicarboxylic acid (bdcH), its monodeprotonated form, i.e. 5-carboxyl­ato-1H-1,3-benzimidazole-6-carboxylic acid (bdc), and one solvent water mol­ecule, the latter being disordered over three sites with site occupancy factors of 0.375 (× 2) and 0.25. In addition, the H atom on one carboxylic acid residue is disordered, being connected to each of the O atoms 50% of the time. The Ag atom is in a virtually linear geometry defined by two N atoms derived from the bdc and bdcH ligands. The three-dimensional supra­molecular structure is stablized by extensive O—H⋯O and N—H⋯O hydrogen bonds. An intramolecular O—H⋯O hydrogen bond is also present

A New Reduced Basis Method for Parabolic Equations Based on Single-Eigenvalue Acceleration

In this paper, we develop a new reduced basis (RB) method, named as Single Eigenvalue Acceleration Method (SEAM), for second-order parabolic equations with homogeneous Dirichlet boundary conditions. The high-fidelity numerical method adopts the backward Euler scheme and conforming finite elements for the temporal and spatial discretization, respectively. Under the assumption that the time step size is sufficiently small and time steps are not very large, we show that the singular value distribution of the high-fidelity solution matrix $U$ is close to that of a rank one matrix. We select the eigenfunction associated with the principal eigenvalue of the matrix $U^\top U$ as the basis of the Proper Orthogonal Decomposition (POD) method to obtain SEAM and a parallel SEAM. Numerical experiments confirm the efficiency of the new method

Small scale clustering of BOSS galaxies: dependence on luminosity, color, age, stellar mass, specific star formation rate and other properties

We measure and analyze galaxy clustering and the dependence on luminosity, color, age, stellar mass and specific star formation rate using Baryon Oscillation Spectroscopic Survey (BOSS) galaxies at $0.48<z<0.62$. We fit the monopole and quadrupole moments of the two-point correlation function (2PCF) and its projection on scales of $0.1$ -- $60.2h^{-1}$Mpc, after having split the catalog in a variety of ways. We find that the clustering dependence is consistent with previous well-established results showing the broad trends expected: For example, that brighter, redder, older, more massive and quenched galaxies are more strongly clustered. We also investigate the dependence on additional parameters previously derived from stellar population synthesis model fits to the spectra. We find that galaxy clustering depends on look-back formation time at a low level, while it has little dependence on metallicity. To understand the physics behind these trends, we fit the clustering with a simulation-based emulator to simultaneously model cosmology and galaxy bias using a Halo Occupation Distribution framework. After marginalizing parameters determining the background cosmology, galaxy bias, and a scaling parameter to decouple halo velocity field, we find that the growth rate of large scale structure as determined by the redshift-space distortions is consistent with previous analysis using the full sample and is independent of the galaxy selection. This demonstrates that cosmological inference using small scale clustering measurements is robust to changes in the catalog selection.Comment: 16 pages, 13+2 figures, comments welcom

Investigation of Energy Efficient Power Coupling Steering System for Dual Motors Drive High Speed Tracked Vehicle

This paper presents an energy efficient power coupling steering system for dual motors drive high speed tracked vehicle. The system consists of a new type of center steering motor, two electromagnetic (EM) clutches, two planetary gear couplers, and two propulsion motors. The motor torque and power required by dynamic steering with different steering radiuses for dual motors drive high speed tracked vehicle were investigated. A motor-speed-based control strategy of dynamic steering is designed to achieve vehicle lateral stability enhancement. The model of the proposed control strategy in RecuDyn and Matlab/Simulink is given. The simulation results of dynamic steering with 0.5B and 2B radius show that understeer in small radius steering can be significantly improved

Web Service Reputation Evaluation Based on QoS Measurement

In the early service transactions, quality of service (QoS) information was published by service provider which was not always true and credible. For better verification the trust of the QoS information was provided by the Web service. In this paper, the factual QoS running data are collected by our WS-QoS measurement tool; based on these objectivity data, an algorithm compares the difference of the offered and measured quality data of the service and gives the similarity, and then a reputation evaluation method computes the reputation level of the Web service based on the similarity. The initial implementation and experiment with three Web services' example show that this approach is feasible and these values can act as the references for subsequent consumers to select the service

Are Ride-Hailing Services Safer Than Taxis? A Multivariate Spatial Approach with Accomodation of Exposure Uncertainty

Despite many research efforts on ride-hailing services and taxis, limited studies have compared the safety performance of the two modes. A major challenge is the need for reliable mode-specific exposure data to model their safety outcomes. Moreover, crash frequencies of the two modes by injury severities tend to be spatially and inherently correlated. To fully address these issues, this study proposes a novel multivariate conditional autoregressive model considering measurement errors in mode-specific exposures (MVCARME). More specially, a classical measurement error structure is used to accommodate the uncertainty of mode-specific exposures estimated, and a multivariate spatial specification is adopted to capture potential spatial and inherent correlations. The model estimation is accelerated by an integrated nest Laplace approximation method. The census tracts in the city of Chicago are set as the spatial analysis unit. The mode-specific exposures (vehicle-mile-traveled) in each census tract are estimated by trip assignments using ride-hailing and taxi trip data in 2019. The modeling results indicate that both ride-hailing crashes and taxi crashes are positively associated with transportation factors (e.g., vehicle-mile-traveled, mode-specific vehicle-mile-traveled, and traffic signal numbers), land use factors (i.e., number of educational and alcohol-related sites), and demographic factors (e.g., median household income, transit ratio, and walk ratio). By comparison, the proposed model outperforms the others (i.e., negative binomial models and multivariate conditional autoregressive model) by yielding the lowest deviance information criterion (DIC), Watanabe-Akaike information criterion (WAIC), mean absolute error (MAE), and root-mean-square error (RMSE). According to the results of t-tests, ride-hailing services are found to be prone to a higher risk of minor injury crashes compared with taxis, despite no significant difference between the risks of severe injury crashes. Methodologically, this study adds to the literature a robust safety evaluation approach for comparing crash risks of different modes. At the same time, practically, it provides researchers, practitioners, and policy-makers insights into the safety management of various mobility alternatives

Draft Genome Sequence of Streptomyces sp. Strain CT34, Isolated from a Ghanaian Soil Sample

Copyright © 2015 Zhai et al. This work was supported by the China “973” program (2012CB721001), the “863” Program (2012AA092201), the National Natural Science Foundation of China (31170467), and the EU FP7 project PharmaSea (312184). K.K., M.J., and H.D. thank the Royal Society–Leverhulme Trust Africa for the financial support (award AA090088) that enabled the sampling of sediments and subsequent isolation of this unique Ghanaian strain.Non peer reviewedPublisher PD