Remote electron effects andπ-πinteractions ofα-diimine nickel complexes

The seminal report ofα-diimine palladium and nickel catalysts in 1995 represented a major breakthrough in the preparation of functionalized polyolefin materials.Owing to the high abundance and low cost of nickel,nickel-based catalysts have great application prospects in the industrialization process of olefin coordination polymerization.In this work,various N-aryl substituents with different electronic effects were synthesized and introduced intoα-diimine ligands.The aspreparedα-diimine nickel catalysts showed high polymerization activity(0.9×10^(7)–3.0×10^(7)g·mol^(−1)·h^(−1))in ethylene polymerization,generating polyethylene products with adjustable molecular weights(Mn values:7.4×10^(4)–146.9×10^(4)g·mol^(−1))and branching densities(31/1000 C–68/1000 C).The resulting polyethylene products showed excellent mechanical properties,with high tensile strength(up to 25.0 MPa)and high strain at break values(up to 3890%).The copolymerization of ethylene and polar monomers can also be achieved by these nicekel complexes,ultimately preparing functionalized polyolefins.

A computational study of the wing-wing and wing-body interactions of a model insect

The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of the body are less than 2%. The reason for this is as following. During each down- or up-stroke, a wing produces a vortex ring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex rings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.

The Impact of Lipid-metabolizing Genetic Polymorphisms on Body Mass Index and Their Interactions with Soybean Food Intake: A Study in a Chinese Population

Objective To evaluate the association of known polymorphisms in the lipid metabolic pathway with body mass index （BMI）, and estimate their interactions with soybean food intake. Methods A community-based cross-sectional survey was conducted in a Chinese Han population. BMI, soybean food intake, and single nucleotide polymorphisms of rs599839, rs3846662, rs3846663, rs12916, rs174547, rs174570, rs4938303, and rs1558861 were measured in 944 subjects. A multivariate logistic regression was used to analyze the association of the studied polymorphisms with BMIs. The expectation-maximization algorithm was employed to evaluate the extent of linkage disequilibrium between pairwise polymorphisms. The gene-environment interaction was assessed in the general multifactor dimensionality reduction model. Results The polymorphisms of rs3846662 and rs3846663 were associated with 10% highest BMIs when comparing to the 10% lowest values both in individuals and haplotype-based association tests. Although no statistically significant gene-environment interactions were found, people with the haplotype composed of C allele in rs3846662 and T allele in rs3846663 and low frequency of soybean intake had significantly hisher risk to overweight and obesity as compared with those with the haplotype consisting of T allele in rs3846662 and C allele in rs3846663 and highly frequent soybean food intake, with an odds ratio of 1.64 （95% confidence interval： 1.15-2.34, P〈0.01） after adjusting for the common confounders. Conclusion Our study has sugsested that rs3846662 and rs3846663 may be the potential candidate polymorphisms for obesity, and their effect on the pathogenesis could be mediated by the frequency of soybean food intake.

Coherence of Disordered Bosonic Gas with Two-and Three-Body Interactions

We theoretically and numerically investigate the coherence of disordered bosonic gas with effective two- and three-body interactions within a two-site Bose-Hubbard model. By properly adjusting the two- and three-body interactions and the disorder, the coherence of the system exhibits new and interesting phenomena, including the resonance character of coherence against the disorder in the purely two- or three-body interactions system. More interestingly, the disorder and three-body interactions together can suppress the coherence of the purely three-body interactions system, which is different from the case in which the disorder and two-body interactions together can enhance the coherence in certain values of two.body interaction. Furthermore, when two- or three- body interactions are attractive or repulsive, the phase coherence exhibits completely different phenomena. In particular, if two- or three-body interactions are attractive, the coherence of the system can be significantly enhanced in certain regions. Correspondingly, the phase coherence of the system is strongly related to the effective interaction energy. The results provide a possible way for studying the coherence of bosonic gas with multi-atoms＇ interactions in the presence of the disorder.

Numerical Study of Effects of Complex Topography on Surface-Piercing Wave-Body Interactions

In this paper, wave-body interactions under the effects of complex topography are investigated numerically by a two-phase incompressible Reynolds-Averaged Navier-Stokes(RANS) solver in OpenFOAM. A submerged bottom-standing structure is distributed below the floating body, and the effects of the water depth and top width of the submerged structure on wave-body interactions are studied. The results show that the submerged structure can affect wave loads and roll motion. The vertical force can be amplified on the fixed body when the water depth of the submerged structure is smaller than half of the water depth of the body. The top width significantly affects the vertical force when the top width is smaller than the incident wave length and larger than the body width. For the free-rolling body, roll amplitude can be increased when the ratio of the incident wave length to the water depth of the submerged structure is large enough. On the resonance condition, roll amplitude is slightly reduced by the submerged structure. The effects of the top width on roll amplitude are remarkable when special conditions are fulfilled.

THE INTERACTIONS BETWEEN WAVE-CURRENTS AND OFFSHORE STRUCTURES WITH CONSIDERATION OF FLUID VISCOSITY

Study of the how held around the large scale offshore structures under the action of waves and viscous currents is of primary importance for the scouring estimation and protection in the vicinity of the structures. But very little has been known in its mechanism when the viscous effects is taken into consideration. As a part of the efforts to tackle the problem, a numerical model is presented for the simulation of the how held around a fixed vertical truncated circular cylinder subjected to waves and viscous currents based on the depth-averaged Reynolds equations and depth-averaged k-epsilon turbulence model. Finite difference method with a suitable iteration defect correct method and an artificial open boundary condition are adopted in the numerical process. Numerical results presented relate to the interactions of a pure incident viscous current with Reynolds number Re = 10(5), a pure incident regular sinusoidal wave, and the coexisting of viscous current and wave with a circular cylinder, respectively. Flow fields associated with the hydrodynamic coefficients of the fixed cylinder, as well as corresponding free surface profiles and wave amplitudes, are discussed. The present method is found to be relatively straightforward, computationally effective and numerically stable for treating the problem of interactions among waves, viscous currents and bodies.

Dinuclear Silver(Ⅰ) Complex Based on 1-Picolyl-3-propylbenzimidazolium Salt: Crystal Structure and Weak Interactions

1-Picolyl-3-propylbenzimidazolium bromide （LBr） was prepared from benzimida- zole by alkylation with 2-chloromethyl-pyridine in the presence of NaH, followed by quaternization with 1-bromopropane. Ligand LBr was treated with AgBr in CH2Cl2 to afford a dinuclear silver（I） complex L2Ag2Br4 （1）. In complex 1, a 2-D supramolecular layer is formed through two types of π-π stacking interactions. Fluorescent emission spectra of ligand LBr and complex 1 are described.

A Silver Complex of 6,7-Dicyanodipyridoquinoxaline:π-Stacking Interactions and Luminescence

The reaction of 6,7-dicyanodipyridoquinoxaline （DICNQ） with AgNO3 in a 1：1 molar ratio by solution method gave a new complex [Ag（DICNQ）2]NO3 1. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the space group Ibca of orthorhombic system with eight formula units in a cell. Crystal data for 1： a = 15.7055（17）, b = 18.411（2）, c = 20.680（2）A, V = 5979.7（11）A3, Z = 8, C32Hl2AgN13O3, Mr = 734.42, Dc = 1.632 g/cm3, μ= 0.734 mm-1, F（000） = 2928, S = 1.023 and T= 293（2） K. The final R = 0.0659 and wR = 0.1927 for 2118 observed reflections with I 〉 2σ（I）, and R = 0.0801 and wR = 0.2196 for all data. The complex builds up a packing structure by π-π stacking interactions and shows a luminescent feature.

A New Cadmium(Ⅱ) Coordination Polymer Extended through Hydrogen Bonds and π-π Stacking Interactions: Synthesis and Photoluminescence Property

A new coordination polymer, {[Cd(OPY)(tdc)(HO)]·H2 O}n(OPY = 4,4?-(oxybis(4,1-phenylene))dipyridine, H2 tdc = thiophene-2,5-dicarboxylic acid), has been synthesized hydrothermally based on a V-shaped ligand OPY. The structure was fully characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction analysis. In1, two OPY ligands and one water molecule acted as terminal ligands coordinating to Cdcation to form [Cd(OPY)HO]units, which are then linked by tdc2-ligands to generate a one-dimensional chain. Every two adjacent chains linked by extensive O–H···O hydrogen bonds constitute one-dimensional double-chains, and such chains are extended into two-dimensional layers via O–H···N hydrogen bonds. These layers are further connected to form a three-dimensional supramolecular architecture via π-π stacking interactions. In addition, the thermal stability and solid state fluorescence property of 1 were also investigated.

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis, a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper, resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom, while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force dements built on the theory of terramechanics acting on each discrete dement. To evaluate and verify the correctness and effectiveness of this new modeling and analysis method, typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method. In full consideration of the particMar structure design of the pilot miner, the special characteristics of the seafioor soil and the hydrodynamic force of near-seafloor currnt, the dynamic simulation analysis of the miner is performed and discussed, which can provide useful guidance and reference for the practical miner system in design and operation. This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.

Effects of three-body interaction on collective excitation and stability of Bose-Einstein condensate

This paper investigates the collective excitation and stability of low-dimensional Bose-Einstein condensates with two- and three-body interactions by the variational analysis of the time-dependent Gross-Pitaevskii-Ginsburg equation. The spectrum of the low-energy excitation and the effective potential for the width of the condensate axe obtained. The results show that： （i） the repulsive two-body interaction among atoms makes the frequency red-shifted for the internal excitation and the repulsive or attractive three-body interaction always makes it blue-shifted; （ii） the region for the existence of the stable bound states is obtained by identifying the critical value of the two- and three-body interactions.

DYNAMIC CHARACTERISTIC ANALYSIS OF A 3-D SEMI-SUBMERGED BODY AS A FLUID-STRUCTURE INTERACTION SYSTEM

An Arnoldi's method with new iteration pattern,which was designed for solving a large unsymmetric eigenvalue problem introduced by displacement-pressure FE (Finite Element) pattern of a fluid-structure interaction system,was adopted here to get the dynamic characteristics of the semi-submerged body. The new iteration pattern could be used efficiently to obtain the Arnoldi's vectors in the shift-frequency technique,which was used for the zero-frequency problem. Numerical example showed that the fluid-structure interaction is one of the important factors to the dynamic characteristics of large semi-submerged thin-walled structures.

Simulation of Water-Soil-Structure Interactions Using Incompressible Smoothed Particle Hydrodynamics

In the present work,an incompressible smoothed particle hydrodynamic(SPH)method is introduced to simulate water-soil-structure interactions.In the current calculation,the water is modelled as a Newtonian fluid.The soil is modelled in two different cases.In the first case,the granular material is considered as a fluid where a Bingham type constitutive model is proposed based on Mohr-Coulomb yield-stress criterion,and the viscosity is derived from the cohesion and friction angle.In addition,the fictitious suspension layers between water and soil depending on the concentration of soil are introduced.In the second case,Hooke’s law introduces elastic soil.In ISPH,the pressure is evaluated by solving the pressure Poisson equation using a semi-implicit algorithm based on the projection method and an eddy viscosity for water is modelled by a large eddy simulation with the Smagorinsky model.In the proposed ISPH method,the pressure is stabilized to simulate the multiphase flow between soil and water.Numerical experiments for water-soil suspension flow of Louvain erosional dam break with flat soil foundation,is simulated and validated using 3D-ISPH method.Coupling between water-soil interactions with different solid structures are simulated.The results revealed that,the suspension layers with the Bingham model of soil gives more accurate results in the experiment as compared to the case of the Bingham model without suspension layers.In addition,the elastic soil model by the Hooke’s law can simulate soil hump accurately as compared to the Bingham model.From the simulations,avoiding erosion behind the structure for preventing the structure break during flood are investigated by using an extended structure or a wedge structure.

A New Cobalt(Ⅱ)Polymer Based on 1-Butylben-zimidazole and Terephthalate Mixed-ligands:Crystal Structure and Weak Interactions

A new cobalt（Ⅱ） polymer with quasi-rectangular cavities, [Co（L）2（TP）·H2O]n 1 （L=1-butylbenzimidazole, TP = terephthalate ion） has been prepared by means of self-assembly of 1-butylbenzimidazole, terephthalic acid and Co（NO3）2·6H2O. The structure of 1 was characterized by X-ray diffraction analysis. In the crystal packing, 2-D supramolecular layers are formed via π-π stacking interactions. The fluorescence emission spectra of L and 1 are described.

Two Cd(Ⅱ) and Cu(Ⅱ) Complexes Based on 1-Butylbenzimidazole: Crystal Structures and Weak Interactions

1-Butylbenzimidazole L reacted with Cd（NO3）2·4H2O to afford complex [CdL（NO3）3H2O]·[HL] 1. The heptacoordinated Cd（Ⅱ） center adopts a distorted pentagongal bipyramidal geometry, and complex [CdL（NO3）3H2O]-entity and the protonated benzimidazium salt [HL]＋ are connected via N–H···O hydrogen bond to form a dimeric unit [CdL（NO3）3H2O]·[HL]. A 3-D supramolecular network of 1 is formed through N–H···O and O–H···O hydrogen bonds together with π-π stacking interactions. Reaction of L with CuCl2 afforded a mononuclear complex, [CuL2Cl2] 2, in which the tetracoordinated Cu（II） center adopts a distorted tetrahedral geometry. In contrast, 2-D supramolecular layers of 2 are formed by C–H···Cl hydrogen bonds. The fluorescent emission spectra of L, 1 and 2 are described.

Effects of effective attractive multi-body interaction on quantum phase and transport dynamics of a strongly correlated bosonic gas across the superfluid to Mott insulator transition

We theoretically investigate quantum phases and transport dynamics of ultracold atoms trapped in an optical lattice in the presence of effective multi-body interaction. When a harmonic external potential is added, several interesting phenom- ena are revealed, such as the broadening and the emergence of a central insulator plateau and the phase transition between superftuid and Mott insulator phase. We also study the transport of the system which runs across the superfluid-insulator transition after ramping up the lattice, and predict a slower relaxation which is attributed to the influence of the multi-body interaction on the mass transport.

A 3D Supramolecular Pd(Ⅱ) Complex via Hydrogen-bonding and Weak M…M Interactions

The reaction of 2,4,6-tris（2-pyridyl）-1,3,5-triazine （tptz） and K2PdCl4 in THF/H2O （10：1） results in the hydrolysis of tptz to bis（2-pyridylcarbonyl）amide anion （bpca）, and affords complex Pd（bpca）Cl 1, which is the first example of Pd（Ⅱ）-promoted hydrolysis of ligands. Crystal data for 1： orthorhombic, space group Pbcn, a = 12.0136（17）, b = 14.180（2）, c = 6.9747（11）A, V= 1188.2（3） A3, Z = 4, Mr = 368.06, Dc = 2.058 g/cm3, F（000） = 720,μ = 1.786 mm^-1, λ（MoKα） = 0.71073 A, T= 293（2） K, 2θmax = 54.9°, GOOF = 1.085, the final R= 0.0647 and wR = 0.1051 for 1234 observed reflections with I 〉 2σ（I） （refinement on F2）. Complex 1 is connected through hydrogen bonding to give a 2D network. And weak Pd...Pd interactions are also found between adjacent molecules with the distance of 3.6074（5） A, so the complex is further extended into a 3D supramolecular structure. Thermal gravity analysis （TGA） shows that 1 exhibits high thermal stability below 310℃. X-ray powder diffraction （XRD） and UV/Vis spectrum of 1 are also discussed.

Effects of three-body interaction on dynamic and static structure factors of an optically-trapped Bose gas

We investigate how three-body interactions affect the elementary excitations and dynamic structure factor of a Bose- Einstein condensate trapped in a one-dimensional optical lattice. To this end, we numerically solve the Gross-Pitaevskii equation and then the corresponding Bogoliubov equations. Our results show that three-body interactions can change both the Bogoliubov band structure and the dynamical structure factor dramatically, especially in the case of the two-body interaction being relatively small. Furthermore, when the optical lattice is strong enough, the analytical results, combined with the sum-rule approach, help us to understand that： the effects of three-body interactions on the static structure Ihctor can be significantly amplified by an optical lattice. Our predictions should be observable within the current Bragg spectroscopy experiment.

Topological quantum-phase coherence in full counting statistics of transport electrons with two-body interaction

The full counting statistics of electron transport through two parallel quantum dots with antiparallel magnetic fluxes is investigated as a probe to detect the topological quantum-phase coherence （TQPC）, which results in the characteristic oscillation of the zero-frequency cumulants including the shot noise and skewness. We show explicitly the phase transition of cumulant spectrum-patterns induced by the topology change of electron path-loops while the pattern period, which depends only on the topology （or Chern number）, is robust against the variation of Coulomb interaction and interdot coupling strengths. Most importantly we report for the first time on a new type of TQPC, which is generated by the two- particle interaction and does not exist in the single-particle wave function interference. Moreover, the accurately quantized peaks of Fano-factor spectrum, which characterize the super- and sub-Poissonian shot noises, are of fundamental importance in technical applications similar to the superconducting quantum interference device.

Modeling of Adhesive Particles Using a Combination of the Two-Body Interaction and Phase-Field Methods

Discrete materials such as powders and granular materials have been widely used due to their specific characteristics. The precise evaluation is accordingly becoming important, and various numerical schemes have been developed. However, the interactions among the constituent particles are still difficult to model precisely. Especially, contact conditions, which vary with material properties and circumstances, are difficult to formulate. In this study, a computational model for simulating adhesive particles on contact in a many-particle system is proposed. The interaction between the particles was represented by a two-body repulsive force that depends on the distance between particles and an additional adhesive force at the contact point. A phase-field variable was introduced to express the surface of each particle, and the adhesive force was formulated using the phase-field distribution. As a result, the adhesion of particles was properly expressed. For a mono-particle system, neighboring particles adhered and uniformly aggregated, while for a dual-particle system, several characteristic patterns were obtained depending on the initial arrangement of the particles. Repulsive contact was also considered as a specific case, and the corresponding results were obtained.