Studies on Some Basic Physical Problems in Macromolecular Condensed State

Macromolecular condensed state involves crystalline state and non-crystalline state of long-chain synthetic and naturally occurring molecules. The noncrystalline state may be a polymeric fluid, a rubbery elastic semi-solid or a rigid glass.

Effect and Mechanism of Solvent Properties on Solution Behavior and Films Condensed State Structure for the Semi-rigid Conjugated Polymers

Solvents have an essential association with polymer solution behavior.However,few researches have been deeply done on this respect.In recent years,our research group focus on the study on effect of solvent properties on solution behavior and film condensed state structure for semi-rigid conjugated polymer up till to apply for optoelectronic device.Herein,influence of solvent properties including solubility of solvent,aromaticity,polarity and hydrogen bonds on semi-rigid polymer chain solution behavior,i.e.,single chain conformation,chain shape,size and chains aggregated density were studied by means of static/dynamic laser light scattering(DLS/SLS)and exponential law etc.Effect of solvent properties on condensed state structure of the semi-rigid conjugated polymer film was studied by UV absorption spectroscopy,PL spectroscopy and electron microscopy etc.The essential reasons for the influence were discovered and the mechanism was revealed.It was found that solution behavior with different solvent properties had an essential physical relationship with chains condensed state structure of the semi-rigid conjugated polymers.More importantly,there was a quantitative structure-activity relationship between solution and film.The key to this relationship depended on the interaction between solvent molecules and the semi-rigid conjugated polymer chains.This interaction could also affect optoelectronic devices performance.This study is of great significance to effectively control the condensed state structure of the semirigid conjugated polymers in the process of dynamic evolution from solutions to films.It not only enriches the knowledge and understanding of both semi-rigid conjugated polymer solution behaviors and film condensed state physics based on polymer physics,but also is meaningful to practical application for conjugated polymer and other traditional polymer systems.

Based on the Second Virial Coefficient(A2)to Study Effect of the Synergistic Action of Solvent and External Electric Field on the Solution Behavior and Film's Condensed State Structure

The solventnatures are crucial to deeply reveal solution behavior of macromolecular chains,physical essence of condensed state structures formation of the film as well as the photoelectronic devices performance.Based on the second virial coefficient(A2),effect of the synergistic action of solvents and external electric field on both solution behavior and the film’s condensed state structure for the semi-rigid conjugated polymer,poly[2-methoxy-5-(2’-ethylhexoxy)-1,4-phenylvinylene](MEH-PPV)was investigated by dynamic/static light scattering,photoluminescence spectroscopy and transmission electron microscopy,etc.It was found that although the MEH-PPV solutions with different solvents(toluene,chlorobenzene,chloroform and tetrahydrofuran)all could generate a response to the external electric field,the degree of response varied significantly with the change of solvent nature.Furthermore,ordered degree of the film from the solutions was also obviously different.The essential reason for this responsive difference was firstly revealed in the research,which actually depended on the degree of interaction between the solute and solvent,and this degree of interaction could be quantitatively described by the second virial coefficient(A2).The bigger the A2,the stronger the interaction between solvent and solute in the solution,and the stronger the response to the external electric field.Further,under the induction of external electric field,chains aggregations with different sizes were formed accompanied by large-scale chains ordered structure in the solution.This ordered structure not only can effectively transfer to film prepared by the precursor solution but also is beneficial to enhance the carrier mobility and device efficiency of the photoelectronic film.

THE SOLID STATE ALDOL CONDENSATION REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES

The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.

Thermodynamical Evaluation on Magnetocaloric Effect of Magnetic Refrigerating Materials Near Room Temperature

The relationship between isothermal magnetic entropy change DELTA S andadiabatic temperature change DELTA T_(ad) was deduced according to the principles of thermodynamics.The MCE and the engineering application were discussed for Gd and several new kinds of magneticrefrigerating materials near room temperature, Gd_5Si_2Ge_2, MnFeP_(0.45)As_(0.55) and LaFe_(11.2)Co_(0.7)Si_(1.1). Isothermal entropy change is proportional to adiabatic temperature change with afactor of T/C (T is temperature, C is heat capacity). When the comparison of magnetacoloric effectis made for two different materials, we should consider isothermal entropy change as well asadiabatic temperature change.

On a class of quasilinear Schrdinger equations

A type of quasilinear Schrodinger equations in two space dimensions which describe attractive Bose-Einstein condensates in physics is discussed. By establishing the property of the equation and applying the energy method, the blowup of solutions to the equation are proved under certain conditions. At the same time, by the variational method, a sutficient condition of global existence which is related to the ground state of a classical elliptic equation is obtained.

THE APPLICATION OF PATTERN RECOGNITION TECHNIQUES IN FAULT DIAGNOSIS OF MACHINERY EQUIPMENT

In this paper, the characteristics of vibration signal of machinery in different running conditions are statistically analysed, and some moments of statistical distribution of signals are selected as the eigenvector to condense the state information. Here, we divide the states of machinery into two: 'good' and 'faulty', and the pattern recognition techniques are used to classify the running conditions of machinery. At the end of this paper, the authors present some test data, and from the results obtained, it's verified that the eigenvector selected is reliable and sensible to faults. And the results also show the effectiveness of classification rule.

Ground and Low-Lying Collective States of Rotating Three-Boson System

The ground and low-lying collective states of a rotating system of N=3 bosons harmonically confined in quasi-two-dimension and interacting via repulsive finite-range Gaussian potential is studied in weakly to moderately interacting regime.The N-body Hamiltonian matrix is diagonalized in subspaces of quantized total angular momenta 0 ≤ L ≤ 4N to obtain the ground and low-lying eigenstates.Our numerical results show that breathing modes with N-body eigenenergy spacing of 2hω⊥,known to exist in strictly 2D system with zero-range(δ-function) interaction potential,may as well exist in quasi-2D system with finite-range Gaussian interaction potential.To gain an insight into the many-body states,the von Neumann entropy is calculated as a measure of quantum correlation and the conditional probability distribution is analyzed for the internal structure of the eigenstates.In the rapidly rotating regime the ground state in angular momentum subspaces L=(q/2)N(N-1) with q=2,4 is found to exhibit the anticorrelation structure suggesting that it may variationally be described by a Bose–Laughlin like state.We further observe that the first breathing mode exhibits features similar to the Bose–Laughlin state in having eigenenergy,von Neumann entropy and internal structure independent of interaction for the three-boson system considered here.On the contrary,for eigenstates lying between the Bose–Laughlin like ground state and the first breathing mode,values of eigenenergy,von Neumann entropy and internal structure are found to vary with interaction.