2-Carb­oxy-1-(3-nitro­phen­yl)ethanaminium perchlorate

In the title compound, C9H11N2O4 +·ClO4 −, the organic cations form centrosymmetric dimers via a pair of O—H⋯O hydrogen bonds between the carboxyl groups. In the crystal, N—H⋯O inter­actions between the protonated amine group and the perchlorate anions and the nitro group connect the components into a two-dimensional network parallel to (001)

2,4-Dimethyl­anilinium perchlorate

The crystal packing of the title compound, C8H12N+·ClO4 −, is stabilized by N—H⋯O hydrogen bonds, the protonated amine group acting as a hydrogen-bond donor with the perchlorate O atoms as acceptors. These connect neighbouring cations and anions, forming a two-dimensional network. Variable-temperature dielectric constant measurements on the salt indicated that no distinct phase transition occurred within the measured temperature range of 80–293 K

Identifying vital edges in Chinese air route network via memetic algorithm

Due to its rapid development in the past decade, air transportation system has attracted considerable research attention from diverse communities. While most of the previous studies focused on airline networks, here we systematically explore the robustness of the Chinese air route network, and identify the vital edges which form the backbone of Chinese air transportation system. Specifically, we employ a memetic algorithm to minimize the network robustness after removing certain edges hence the solution of this model is the set of vital edges. Counterintuitively, our results show that the most vital edges are not necessarily the edges of highest topological importance, for which we provide an extensive explanation from the microscope of view. Our findings also offer new insights to understanding and optimizing other real-world network systems

Oxonium 2-carb­oxy-3-(2-fur­yl)acrylate

In the title compound, H3O+·C8H5O5 −, neighbouring cations and anions are linked by O—H⋯O hydrogen bonds, forming a one-dimensional chain framework along [001]. The crystal structure is further stabilized by π–π inter­actions, with centroid–centroid distances of 3.734 (3) Å

2-Carb­oxy-1-phenyl­ethanaminium nitrate

In the title salt, C9H12NO2 +·NO3 −, the cation and anion are linked by a bifurcated N—H⋯(O,O) hydrogen bond. The crystal packing is stabilized by inter­molecular N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds, which connect neighbouring cations and anions, resulting in a two-dimensional network

3,5-Dicarboxyanilinium nitrate dihydrate

In the crystal of the title compound, C8H8NO4 +·NO3 −·2H2O, the 5-ammonio­isophthalic acid cations, the nitrate anions and the water mol­ecules are linked by N—H⋯O, O—H⋯O and C—H ⋯O hydrogen bonds into a three-dimensional network. The structure is further stabilized by aromatic π–π stacking inter­actions, with centroid–centroid separations of 3.827 (2) Å

Noise in Genotype Selection Model

We study the steady state properties of a genotype selection model in presence of correlated Gaussian white noise. The effect of the noise on the genotype selection model is discussed. It is found that correlated noise can break the balance of gene selection and induce the phase transition which can makes us select one type gene haploid from a gene group.Comment: 8 pages, 4 figure

2,2′-Bis(4-nitro­phen­oxy)-1,1′-binaphth­yl

The title compound, C32H20N2O6, was synthesized by the reaction of 1,1′-binaphthyl-2,2′-diol and 4-nitro­phenol in the presence of K2CO3. The two naphthalene systems make a dihedral angle of 73.70 (5)°. The crystal packing involves mol­ecules connected by C—H⋯O hydrogen bonds into a chain along the c axis

catena-Poly[cadmium(II)-μ-benzene-1,2-diamine-κ2 N:N′-di-μ-chlorido]

The title compound, [CdCl2(C6H8N2)]n, is a coordination polymer prepared by the hydro­thermal reaction of cadmium chloride and o-diamino­benzene. The cadmium cation, located on an inversion center, is octa­hedrally coordinated by four Cl atoms at equatorial sites and two N atoms from two ligands at the axial sites. Cd atoms are bridged by Cl atoms, forming extended chains parallel to [010]. Neighboring chains are connected by N—H⋯Cl hydrogen bonds

Current Reversals in a inhomogeneous system with asymmetric unbiased fluctuations

We present a study of transport of a Brownian particle moving in periodic symmetric potential in the presence of asymmetric unbiased fluctuations. The particle is considered to move in a medium with periodic space dependent friction. By tuning the parameters of the system, the direction of current exhibit reversals, both as a function of temperature as well as the amplitude of rocking force. We found that the mutual interplay between the opposite driving factors is the necessary term for current reversals.Comment: 9 pages, 7 figure