20-O-β-d-Xylopyranos­yl(1→6)-β-d-glucopyranosyl-20(S)-protopanaxadiol methanol solvate

The title compound, C41H70O12·CH4O, was prepared by microbial transformation. Within the steroid skeleton of the mol­ecule, three six-membered rings exhibit a chair conformation, while the five -membered ring adopts an envelope conformation. The two pyranosyl rings also adopt chair conformations. The mol­ecules are held together by an extensive O—H⋯O hydrogen-bonding network

China's Role in the Rising of the South: Vision for 2030

This article examines China's major development contributions, looking at its wider impact on world development. In particular, the article examines the impact of China's development on the changing pattern between the North and South and the human development index. The factors and related regimes behind these phenomena are discussed and a conceptual model is constructed, providing a meta?analysis of the evolution of China's role, based on the structural interpretation of external impetus and barriers, as well as internal advantages and shortcomings. The authors' long?term projections show that the rise of the South, led by China, will be the most important shift in the world's landscape with respect to the development of the emerging world, perhaps leading other large developing economies to play a more prominent role in international development in the future, bringing common development, common prosperity and common progress to the world

Incompressible SPH Based on Rankine Source Solution for Water Wave Impact Simulation

AbstractSmoothed Particle Hydrodynamics (SPH) is a Lagrangian meshless particle method. It was originally developed to simulate astrodynamics but has been extended to model dynamics problems with violent motions in many areas. This paper is based on ISPH and its pressure time history is transformed into another equation based on a Rankine source solution. In the new formulation of ISPH, the governing equation for pressure does not include any derivatives of unknown functions and so overcomes the problems associated with direct numerical approximation to second derivatives in existing ISPH formulation, and some important numerical handling techniques will also be included, like free surface particle identification method and solid boundary discrete scheme. The newly improved method will be applied to model various wave and wave impact interaction with different angle slopes, and the results of comparison with experimental data are also given. According to the comparison of pressure time history, this new method can get a good agreement with experimental results

Solvatochromic Parameters of the Binary Mixtures of Imidazolium Chloride Ionic Liquid Plus Molecular Solvent

Imidazolium-based chloride ionic liquids (ILs) have exhibited remarkable performance in several important applications such as biomass dissolution and extraction, but their large viscosity is a non-negligible problem. Adding molecular co-solvents into chloride ILs is effective in reducing viscosity; nevertheless, understanding of the accompanied change of thermodynamic polarity is quite few. Therefore, in this work we reported three Kamlet-Taft solvatochromic parameters, including dipolarity/polarizability π*), hydrogen-bond acidity (α) and hydrogen-bond basicity (β), for the binary mixtures of several imidazolium-based chloride ILs plus either dipolar protic solvents (water and methanol) or dipolar aprotic solvents (dimethyl sulfoxide, N,N-dimethylformamide and acetonitrile). The results demonstrated that those parameters could be altered by the structure of IL and type of co-solvent owing to the solute-solvent and solvent-solvent interactions. The structure of alkyl chain of cation had considerable impact on the π* variation of IL aqueous solution against IL concentration but hardly affected other mixtures. Moreover, remarkable preferential solvation of probes was observed for β and α in the mixtures of IL and dipolar aprotic co-solvents, whereas the hydrogen-bond interactions between IL and dipolar protic co-solvent enabled the preferential solvation to be alleviated and resulted in more linear variation of β and α against the molar fraction of IL. The results not only contribute to a better understanding of the effect of co-solvent on imidazolium-based chloride ILs, but also are instructive for improving the thermodynamic performance of IL-based applications via providing IL+co-solvent mixtures with desirable physicochemical properties