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A new mercury coordination polymer was successfully prepared from HgCl2 and 5-methyltetrazole (Hmtz) and characterized by elemental analysis, thermal analysis, luminescence, theoretical calculation, powder X-ray diffraction and single-crystal X-ray diffraction. Complex 1 is a three-dimensional (3D) hybrid framework constructed from 1D double mercury halide chains and mtz−, and it has an unprecedented ‘AFUQOH’ topological network. Time-dependent density functional theory (TDDFT) calculations reveal that the mechanisms of the fluorescence emission of 1 are dominantly resulted from the metal-to-ligand charge transfer (MLCT) and ligand-to-metal charge transfer (MLCT). Impressively, acentric complex 1 displays not only second harmonic generation (SHG) response but also ferroelectric behaviors.

The objective of this study was to investigate five nutrient factors of the forest topsoil (0–20 cm), including pH, soil organic matter (SOM), total nitrogen (STN), available phosphorus (AP), and available potassium (AK). This study adopted the revised Nemerow index method to conduct a comprehensive quantitative evaluation on the soil nutrition contents, and using geostatistical method to address the spatial variability of soil properties in hilly and mountainous regions, southern China. Data were analyzed both statistically and geostatistically on the basis of semivariogram. Our results indicate that the soil is generally acidic, containing rich SOM and STN, but lacks AP and AK. Most of the sub-indexes of fertility were at grade III, showing a middle level. According to the coefficient of variations (CV), the five soil nutrient factors can be ranked in decreasing order as follows: AP > SOM > AK > STN > pH. There were differences between the sub-indexes of fertility, which could be ranked as follows: PSOM > PAK > PSTN > PpH > PAP. The semi-variation functions for the five soil nutrient factors studied here show some spatial structure features, over a range of 23–274 km. All nutrient factors had different nugget-to-sill ratios in each region, which varied from 10 to 50%, suggesting a strong or medium correlation. Thus, it can be concluded that the nutrient spatial distribution of the study area was the result of the combined action of structural factors and random factors, and the factors affecting the soil nutrients of the research area are highly complex. We will develop more targeted research plans about soil nutrients of study area in the next time.

A new compound of [Cu8(Metz)9](OH)·xH2O (x≈3) (1) (Metz = 5-Methyltetrazole) has been prepared and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The crystal is of hexagonal, space group P63/m with a = b = 13.988(1) A, c = 16.309(2) A, α = β = 90°, γ = 120°, V = 2 763.5 (4) A3, Mr = 1327.13, D c = 1.595 g cm−3, Z = 2, F(000) = 1 316, μ = 3.076 mm−1, the final R = 0.0494 and wR = 0.1532 for 1,731 observed reflections (I > 2σ(I)). In this compound, the [(CuII)2(CuI)6(Metz)9]+ cationic clusters are connected together through CuI cations and Metz ligands and result in a three-dimensional framework. Remarkable, three-dimensional intersecting channels exist in it. The variable temperature magnetic investigations indicate that 1 exhibits typical antiferromagnetic behaviors. N2 gas adsorption measurements at 77 K showed that compound 1 possesses permanent porosities.

A new compound of CuCl(QOA)(H2O) (1) [QOA = (8-quinolinyloxy)acetate] has been prepared and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. The crystal is of orthorhombic, space group P212121 with a = 5.364(1) A, b = 13.876(3) A, c = 15.435(3) A, V = 1,148.8(4) A3, Mr = 319.19, Dc = 1.846 g cm−3, Z = 4, F(000) = 644, μ = 2.138 mm−1, flack parameter = 0.00(17), the final R = 0.0311 and wR = 0.0646 for 2,179 observed reflections (I > 2σ(I)). Compound 1 consists of one-dimensional helical chains deriving from CuCl(QOA)(H2O) units linked by hydrogen bonds and further extend into a 3D supramolecular structure through Van der Waals interactions, and it exhibits strong luminescent emission at room temperature.

Gear faults are among the main causes of rotating machines breakdown in industrial applications. Intelligent condition monitoring for fault diagnosis can be helpful for detecting gear faults in an early stage so as to reduce production loss and, in addition, improve operation safety and reliability. In this work, we present an intelligent gear fault diagnosis scheme based on a novel classification model, namely the fuzzy lattice neurocomputing (FLN) classifier model. Five gear states including one healthy state and four defective states are tested in a two-stage gearbox. Statistical parameters in both the time domain and the frequency domain of vibration signals, acquired from gearbox, are used as features. We conducted experiments on a benchmark dataset as well as on a gear faults dataset to evaluate both the classification performance and the computational cost of the FLN classifier comparatively with alternative classification methods from the literature including artificial neural networks, support vector machines and decision trees. Our study has demonstrated that the FLN model yields better classification performance with smaller computational cost than the aforementioned alternative methods. The FLN classifier can further be used for condition monitoring and fault diagnosis in other mechanical systems.

Two nickel coordination compounds with m-aminophenol-N,N,O-triacetic acid (H3L), [Ni(L)·(H2O)3]2·Ni(H2O)6·4.3H2O (1), and [Ni(L)·H2O]2·Ni(H2O)6 (2), were obtained under similar reaction conditions but at different synthesis temperature. Single crystal X-ray diffraction analysis reveals that both coordination compounds exhibit discrete dimeric entity structures and contain hexaaquanickel cations acting as counter-ions. Unit cell data for (1): triclinic, space group P-1, a = 7.9977(16), b = 10.475(2), c = 12.952(3) A and α = 107.36(3), β = 99.66(3), γ = 96.15(3)°; and for (2): monoclinic, space group P21/c, a = 13.524(3), b = 8.5703(17), c = 13.820(3) A and β = 95.25(3)°. In (1), O–H⋯O hydrogen bonds link the complex anions into a dimeric unit. But in (2), the dimeric unit is generated from two Ni centers bridged by two ligands. Extensive hydrogen bond interactions exist in both coordination compounds, and connect the complex anions, hexaaquanickel cations and/or water molecules, resulting in three-dimensional supramolecular structures. The compounds also have been characterized by elemental analysis, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), FT-IR and UV–Vis spectra. More coordinated water molecules of metal ion are substituted by N and/or O donors of ligand at higher reaction temperature.

The first example of isonicotinic acid compounds with infinite mercury halide chains, [HgCl2(C6NO2H5)]nn[HgCl2]n(C6NO2H5) (1), was synthesized through hydrothermal reactions and structurally characterized by X-ray single crystal diffraction. Compound 1 features a one-dimensional (1-D) motif, based on infinite 1-D [HgCl2(C6NO2H5)]n chains, neutral HgCl2 moieties and isolated isonicotinic acid molecules. The [HgCl2(C6NO2H5)]n chains, HgCl2 moieties and isonicotinic acid molecules are interlinked by hydrogen bonds and π-π interactions to give a two-dimensional supramolecular layer. Photoluminescent investigation reveals that the title compound exhibits a strong emission in blue region. The emission band is identified as the π -π* transitions of the isonicotinic acid moieties.

The title complex, (N,N′-dimethyl-4,4′-bipyridinium)[Cd2(μ 2-Cl)4Cl2]n (1), in which the N,N′-dimethyl-4,4′-bipyridinium was generated in situ, was synthesized via hydrothermal reaction. X-Ray diffraction analysis revealed that the structure of 1 consisted of MV 2+ (MV 2+ = N,N′-dimethyl-4,4′-bipyridinium) cationic moieties and infinite [Cd2(μ 2-Cl)4Cl2]n anionic chains. The cadmium atom was bound by one terminal chlorine atom and four μ 2-bridging chlorine atoms, yielding a slightly distorted triangular bipyramid. Photoluminescent investigation revealed that the complex displayed an emission in greenish blue region.

In this paper, we describe the nonlinear models of a rod in three-dimensional space based on the Cosserat theory. Using the pseudo-rigid body method and variational principle, we obtain the motion equations of a Cosserat rod including shear deformations.