QCD PERTURBATION THEORY AND NUCLEI (1) THE ENERGY SHIFTS OF HADRENS AND HADRONS MASS DIFFERENCE MASS DIFFERENCE

QCD perturbation theory for confined quarks and gluons (inhadrons) is discussed.Based on the equivalent potential for the quark-gluon interaction derived, the energyshifts of hadrons and hadron mass difference in MIT bag (cavity) model and correcpond-ing approximation of the w. f. with Gassian form are calculated.     

Theoretical Investigations of Nonlinear Optical Properties of Transition Metal Cluster Anions

In the framework of density functional theory （DFT）, the electronic excitations and nonlinear optical （NLO） properties of six binuclear transition metal cluster anions with the formula of [Ch2M-（μ-Ch）2-M＇CN]^2- （M = Mo, W; Ch = S, Se; M＇ = Cu, Ag） have been systemically investigated at both cases of gas phase and DMF solution. The obtained electronic absorption spectra reveal that the element replacements of metals M and ligands Ch have significant influence on the absorptions, especially on the low-lying ones. In addition, the transitions of μ-Ch→M are dominant for the low-lying excitations, whereas the transitions of M＇→M as well as Ch→M are mainly responsible for the higher excitations. The calculated molecular first and second hyperpolarizabilities present the remarkable element substitution and solvent effects. The analyses show that the transitions involving μ-Ch→M charge transfer make the critical contributions to the first hyperpolarizability t, and that the charge transfers from the moieties of MCh4 to M＇CN as well as those of μ-Ch→M and M＇→M are responsible for the second hyperpolarizability y. Moreover, the introduction of solvent leads to the results that the transitions within the moieties of MCh4 and M＇CN make larger contributions to the hyperpolarizability, especially to γ.     

Macroporous Morphology of the Titania Films Prepared by a Sol-Gel Dip-Coating Method from the System Containing Poly(Ethylene Glycol). I. Effect of Humidity

The influence of humidity upon the macroporous morphology of the titania films has been studied for a sol-gel dip-coating system containing poly(ethylene glycol) (PEG). The water adsorption from the ambient atmosphere modifies the polycondensation rate of TiO2 oligomer and the phase separation rate between the TiO2-PEG complex and solvent mixture, and greatly varies the macroscopic morphology of the resultant TiO2 film.     

TDDFT Studies of Electronic Structure and First Hyperpolarizability of Tetra-nuclear Cubane-like Transition Metal Clusters

A series of tri-nuclear transition metal clusters with incomplete cubane-like configurations have been studied by TDDFT method. The calculations show that they have enormously large second-order polarizabilities () and are potential nonlinear optical materials for infrared double frequency conversion1. In this paper some tetra-nuclear transition metal clusters with cubane-like configurations, MCu3X4 (PPh3)3 (M=W, Mo; X= S, O, Cl, Se, Br), were studied by TDDFT method for a reference…     

Synthesis of Glc1Man9‐Glycoprotein Probes by a Misfolding/Enzymatic Glucosylation/Misfolding Sequence

Glycoproteins in non‐native conformations are often toxic to cells and may cause diseases, thus the quality control (QC) system eliminates these unwanted species. Lectin chaperone calreticulin and glucosidase II, both of which recognize the Glc₁Man₉ oligosaccharide on glycoproteins, are important components of the glycoprotein QC system. Reported herein is the preparation of Glc₁Man₉‐glycoproteins in both native and non‐native conformations by using the following sequence: misfolding of chemically synthesized Man₉‐glycoprotein, enzymatic glucosylation, and another misfolding step. By using synthetic glycoprotein probes, calreticulin was found to bind preferentially to a hydrophobic non‐native glycoprotein whereas glucosidase II activity was not affected by glycoprotein conformation. The results demonstrate the ability of chemical synthesis to deliver homogeneous glycoproteins in several non‐native conformations for probing the glycoprotein QC system.     

双圈图的零度与其匹配数之间的关系

Let G be a graph with n(G) vertices and m(G) be its matching number.The nullity of G,denoted by η(G),is the multiplicity of the eigenvalue zero of adjacency matrix of G.It is well known that if G is a tree,then η(G) = n(G)-2m(G).Guo et al.[Jiming GUO,Weigen YAN,Yeongnan YEH.On the nullity and the matching number of unicyclic graphs.Linear Alg.Appl.,2009,431:1293 1301]proved that if G is a unicyclic graph,then η(G)equals n(G)-2m(G)-1,n(G)-2m(G),or n(G)-2m(G) +2.In this paper,we prove that if G is a bicyclic graph,then η(G) equals n(G)-2m(G),n(G)-2m(G)±1,n(G)-2m(G)±2or n(G)-2m(G) + 4.We also give a characterization of these six types of bicyclic graphs corresponding to each nullity.     

A phenomenological theory for polarization flop in spiral multiferroic TbMnO<Subscript>3</Subscript>

A phenomenological Landau theory has been used to explain magnetic field-driven polarization flop in TbMnO ₃. The Néel wall-like magnetic structure in spiral multiferroics induces a space-dependent internal magnetic field which exerts a torque on spins to rotate bc-spiral to ab-spiral. The external magnetic field is argued to be competing with easy axis anisotropy and the system stabilizes when anisotropy is minimum. With the help of Landau free energy with DM magnetoelectric coupling and a general ansatz for magnetization, the phenomenon of polarization flop has been explained. Relation between T_flop and critical magnetic field has been established and found to be in good agreement with the experiment. This could be an indication that anisotropy of the system is temperature- and magnetic field-dependent.     

Efficient synthesis of MUC4 sialylglycopeptide through the new sialylation using 5-acetamido-neuraminamide donors

Sialylation reactions using a new sialyl donor, diethyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-O-beta-D-glycero-D-galacto-2-nonulopyranosylonamide phosphite (Neu5Ac-1-amide-2-phosphite) derivatives, and the synthesis of the sialyl-T N-MUC4 glycopeptide are described. The sialylation was performed in CH2Cl2 solvent toward the 6-hydroxyl group of several monosugar acceptors and generated alpha-sialoside in good yield under low temperature and TMSOTf activation system. Amide derivatives of sialoside were easily converted into naturally occurring sialoside after hydrolysis of the amide group. Sialyl-alpha(2,6)-GalN3 was also prepared by this new sialylation protocol, and then this sialoside was further converted into a Fmoc-protected sialyl-TN serine derivative for solid-phase glycopeptides synthesis. The solid-phase glycopeptide synthesis using this sialyl-TN serine derivative in which the sugar hydroxyl group was free afforded the target sialyl-TN-MUC4 glycopeptide.