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In this work, tetrazole-functionalized stationary phase was prepared with nitrile-modified silica by an ammonium-catalyzed (3 + 2) azide-nitrile cycloaddition reaction. The prepared stationary phase was used for separation of nucleobases and nucleosides by hydrophilic interaction chromatography (HILIC) mode. A typical HILIC mechanism was observed at higher content of acetonitrile (>85%, v/ v) in the mobile phase. The retention mechanism of the column was investigated by the models used for describing partitioning and surface adsorption through adjustment ratio of water in the mobile phase, and by the influence of salt concentration, buffer pH, and temperature on the retention of solutes. The results illustrated that the surface adsorption through hydrogen bonding dominated the retention behavior of nucleobases/nucleosides under HILIC mode. From the separation ability, the tetrazole-functionalized stationary phase could become a valuable alternative for the separation of the compounds concerned. [ABSTRACT FROM AUTHOR]

This paper examines, how individual preferences for redistribution in general and redistribution to improve access to education, improve social protection for the poor, reduce income inequality and reduce unemployment depend on beliefs about what determines one’s lot in life and self-assessed prospects for climbing the social ladder in urban China. We find that beliefs about what determine one’s lot in life and subjective perceptions of future mobility are correlated with preferences for redistribution. We find that those who believe one’s lot in life is outside their control are generally more likely to favour redistribution. We show that this result is consistent with the existence of an altruism effect among the rich and entitlement effect among the poor. These findings are robust to the inclusion of control variables for the respondent’s personal characteristics and the location in which he or she lives. [ABSTRACT FROM AUTHOR]

The bounded-iteration construct foreach x in R/p do t od is very commonly used in database programming, due to the fact that database programs are dominated by data retrieval and manipulation tasks rather than by complex computations. Hence in database programming language design, it is important to understand the expressive power of the bounded-iteration construct and its relationship with other language constructs. We study the bounded-iteration construct within the context of a simple database programming language called the iterative transaction language. The language is shown to have NPTIME expressive power, and the deterministic subclass of it has PTIME expressive power, without any extra machineries or restrictions. We show that the bounded-iteration construct is essential for achieving this expressiveness, by characterizing its relationship with other constructs in the language. We also identify another natural subclass of iterative transactions called first-order transactions with exactly first-order expressive power. The complexity of first-order transactions in terms of nested iterations and intermediate states is connected further to the complexity of first-order updates in terms of quantification depth. [ABSTRACT FROM AUTHOR]