Research on the complicated dynamical behaviors of nonlinear ecosystems (II)

This paper is a further study of reference [1]. In this paper, we mainly discuss the complicated dynamical behaviors resulting from a simple one-dimensional model of nonlinear ecosystems: fixed point motion, periodic motion and chaotic motion etc., and briefly discuss the universality of the complicated dynamical behaviors, which can be described by the first and the second M. Feigenbaun. constants. At last, we discuss the one-side lowering phenomenon due to near unstabilization when the nonlinear ecosystem approaches bifurcation points from unbifurcation side. It is of important theoretical and practical meanings both in the development and utilization of ecological resources and in the design and management of artifitial ecosystems.Supported by the Youth Science Fundation of Chinese Academia Sinica and Youth Fundation of Lanzhou Unviersity.     

Operation analysis of natural resources and their pan-weighted network models

In this paper, we propose a competition-share 3-category principle, on which we unite the problems of natural resources, energy, population and environment and so on into a mutual scheme, and provide a united model for the comprehensive research on these problems. This makes the idea of operation analysis of natural resources clearer and the relationships between each of their parts more obvious. On the basis of the above discussion, we propose mathematical models for the operation analysis of multi-networks and the solution of the above global comprehensive problems. We discuss, especially, Shengke (growth and restraint) relationships between two networks of natural resources and share-competitors and their analysis models, providing mathematical tools for solving the problems of the resource-population and the resource-economy, etc. Supported by Science Fund of Lanzhou University.     

Synthesis,crystal structures and characterizations of three new copper(II) complexes including anti‐inflammatory diclofenac

Three new diclofenac‐based copper(II) complexes, namely tetrakis{μ‐2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ²O:O′}bis(methanol‐κO)copper(II), [Cu₂(μ‐dicl)₄(CH₃OH)₂] ( 1 ), bis{2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ²O,O′}bis(1‐vinyl‐1H‐imidazole‐κN³)copper(II), [Cu(dicl)₂(vim)₂] ( 2 ), and bis{2‐[2‐(2,6‐dichloroanilino)phenyl]acetato‐κ²O,O′}bis(1H‐imidazole‐κN³)copper(II), [Cu(dicl)₂(im)₂] ( 3 ) [dicl is diclofenac (C₁₄H₁₀Cl₂NO₂), vim is 1‐vinylimidazole (C₅H₆N₂) and im is imidazole (C₃H₄N₂)], have been synthesized and characterized by elemental analysis, FT–IR spectroscopy, thermal analysis and single‐crystal X‐ray diffraction. X‐ray diffraction analysis shows that complex 1 consists of dimeric units in which the dicl ligand exhibits a bidentate syn,syn‐μ₂ coordination mode linking two copper(II) centres. Complexes 2 and 3 have mononuclear units with the general formula [Cu(dicl)₂L₂] (L is vim or im) in which the Cu^II ions are octahedrally coordinated by two L and two dicl chelating ligands. The L and dicl ligands both occupy the trans positions of the coordination octahedron. The different coordination modes of dicl in the title complexes were revealed by Fourier transform IR (FT–IR) spectroscopy. The spin matching between the copper(II) centres in the dimeric [Cu₂(μ‐dicl)₄(CH₃OH)₂] units was also confirmed by magnetic data to be lower than the spin‐only value and electron paramagnetic resonance (EPR) spectra. The thermal properties of the complexes were investigated by thermogravimetric (TG) and differential thermal analysis (DTA) techniques.     

Solving the problem of linear viscoelasticity for multiply connected anisotropic plates

This paper describes the method for solving the problems of linear viscoelasticity for thin plates under the influence of bending moments and transverse forces. The small parameter method was used to reduce the original problem to a sequence of boundary-value problems solved via complex potentials of the bending theory of multiply connected anisotropic plates. The general representations of complex potentials and boundary conditions for their determination are obtained. The method for determining the stress state of the plate at any time with respect to complex approximation potentials is developed by replacing the powers of the small parameter by the Rabotnov operators. The problem of a plate with elliptical holes is solved. The numerical calculation results in the case of a plate with one or two holes are given. The variation of bending moments in time until stationary condition is reached is studied, and the influence of geometric characteristics of the plate on these variable is described.     

Dense inverse subsemigroups of a topological inverse semigroup

In this paper we study dense inverse subsemigroups of topological inverse semigroups. We construct a topological inverse semigroup from a semilattice. Finally, we give two examples of the closure of B _{( −∞, ∞ )}¹, a topological inverse semigroup obtained by starting with the real numbers as a semilattice with the operation a ∨ b=sup{a,b}. The author would like to thank to the referee for useful suggestions.     

Lipid diffusion in giant unilamellar vesicles is more than 2 times faster than in supported phospholipid bilayers under identical conditions

The lateral diffusion coefficients of a BODIPY tail-labeled lipid in two model systems, namely, free-standing giant unilamellar vesicles (GUVs) and supported phospholipid bilayers (SPBs), were determined by fluorescence correlation spectroscopy (FCS) using the Z-scan approach. For the first time, the performed measurements on 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers maintain exactly the same experimental conditions for both systems, which allows for a quantitative comparison of lipid diffusion in these two commonly used model membranes. The results obtained revealed that the lipid mobility in free-standing bilayers (D=7.8+/-0.8 microm2 s-1) is significantly higher than in the bilayer created on the solid support (mica) (D=3.1+/-0.3 microm2 s-1).     

Simple analysis of four bisphosphonates simultaneously by reverse phase liquid chromatography using n-amylamine as volatile ion-pairing agent

Volatile organic amine was used as the mobile phase addictive during the separation of four bisphosphonates (alendronate, pamidronate, zoledronic acid and etidronate). An isocratic liquid chromatography method with evaporative light-scattering detection (ELSD) was developed for these bisphosphonates which are not retained on non-polar column and lack chromophore for detection. The analytes have sufficiently separated from each other on a Phenomenex C18 column. The effects of mobile phase composition and instrumental parameters of ELSD were studied. This newly developed method enables direct measurement for analysis of bisphosphonates without the need of derivatization. This developed method provides high separation and specificity to bisphosphonate analysis. In quantitative analysis, the method showed satisfactory precision (less than 2.8%) and accuracy (higher than 94.4%), good linearity (r=0.9991-0.9997) and sufficient sensitivity (15-18 microg/ml). It can be easily and conveniently adopted for the routine quality control analysis.     

Hydrothermal synthesis and characterization of the first 1-D indiumphosphate chain In2(HPO4)2(H2PO4)2F2·C4N2H12, a precursor for high dimensional structures

The first one-dimensional (1-D) indiumphosphate chain, In₂(HPO₄)₂(H₂PO₄)₂F₂·C₄N₂H₁₂ (1), has been hydrothermally prepared using piperazine (PIP) as a template. The structure consists of infinite chains of trans,trans-corners-sharing InO₄F₂ octahedra with the adjacent octahedra being bridged by tetrahedral PO₃(OH) and PO₂(OH)₂ units, which are H-bonded with amine groups of the organic cations. Interestingly, this macroanionic chain InP₂O₈H₃F⁻ is similar to that found in the mineral tancoite-like chains and has potential to further set up higher-dimensional networks. On heating 1 in the presence of additional phosphoric acid at 180 °C under hydrothermal condition, compound 2, In₂(OH)(H₂O)(PO₄)₂·H₃O·H₂O, possessed a 3-D structure building from the repetition of a secondary building unit is obtained. When 1 is heated with additional PIP, an unknown phase, compound 3 is formed. Finally, on treatment with another amine, such as diethylenetriamine or 1,4-diaminobutane, at 180 °C, 1, as a precursor, can convert into a previously known 3-D framework structure with 16-membered ring compound 4. Compounds 1 and 2 are determined by single-crystal X-ray diffraction. Furthermore, 1 is characterized by X-ray powder diffraction, IR spectroscopy, inductively coupled plasma analysis, thermogravimetric analysis and differential thermal analysis.     

Static secondary ion mass spectrometry (S-SIMS) for the characterization of surface components in mineral particulates

The feasibility of static secondary ion mass spectrometry (S-SIMS) for the detection of molecule specific information from complex materials, such as natural clay and soil samples, has been investigated. Ion trap (IT), as well as triple quadrupole (TQ) instruments, have been used for mass analysis. Secondary ion images have been acquired using time-of-flight (TOF) S-SIMS. The generation of molecular adduct ions from thin and thick layers on the mineral substrates has been investigated using KBr as a simple model system. Results show that molecular adducts of KBr can be indeed detected from the spiked materials. However, the concentrations of the spiking solutions have to be significantly larger than expected from the surface area measured by gas adsorption techniques. In addition imaging analysis has evidenced that the detection of adduct ions in the mass spectra directly relates to the presence of local micro-crystallites.     

Neutrino Production via e-e+ Collision at Z-Boson Peak

The production of the three normal neutrinos via e^-e⁺ collision at Z-boson peak (neutrino production in a Z-factory) is investigated thoroughly. The differences of v_e-pair production from v_μ-pair and v_τ-pair production are presented in various aspects. Namely the total cross sections, relevant differential cross sections and the forward-backward asymmetry etc. for these neutrinos are presented in terms of figures as well as numerical tables. The restriction on the room for the mixing of the three species of light neutrinos with possible externals (heavy neutral leptons and/or sterile neutrinos) from refined measurements of the invisible width of Z-boson is discussed.