General results on preferential attachment and clustering coefficient

This is a review paper that covers some recent results on the behavior of the clustering coefficient in preferential attachment networks and scale-free networks in general. The paper focuses on general approaches to network science. In other words, instead of discussing different fully specified random graph models, we describe some generic results which hold for classes of models. Namely, we first discuss a generalized class of preferential attachment models which includes many classical models. It turns out that some properties can be analyzed for the whole class without specifying the model. Such properties are the degree distribution and the global and average local clustering coefficients. Finally, we discuss some surprising results on the behavior of the global clustering coefficient in scale-free networks. Here we do not assume any underlying model.     

Muography of Large Natural and Industrial Objects

Physics of Atomic Nuclei -     

Nanosized cation exchanger for the electrophoretic separation and preconcentration of catecholamines and amino acids

The first example of application of nanosized polystyrene-based cation exchanger (NSCE) with sulfo groups as a dynamic coating of capillary walls was demonstrated. The conditions of dynamic coating formation were optimized and ensured the long-term stability of the coating. Capillary-to-capillary and day-to-day repeatabilities were 4% and 3%, correspondingly. The NSCE coating stability at various pH and influence of pH on the EOF mobility were investigated. The developed NSCE-modified coated capillaries provided improved resolution (R_s = 0.9–3.2 for catecholamines and R_s = 1.7–2.8 for amino acids) and efficiencies (330–520 ×10³ t.p./m) of basic analytes, which are 1.5 times higher compared to untreated capillary. The optimized conditions were as follows: 50 mM phosphate buffer solution at pH 2.2 with 5 μM NSCE. The effect of the NSCE concentration in BGE on the electrophoretic mobilities of the analytes was investigated. The various online concentration techniques were tested in order to decrease the LODs. The simultaneous application of NSCE capillaries and field-amplified sample stacking provided the lowest LODs of catecholamines and amino acids and allowed to determine these analytes in human urine.