Li Wen-Zhu

Water Soluble C60-Liposome and the Biological Effect of C60 to Human Cervix Cancer Cells

A preparative technique to obtain water soluble C60-liposome by means of molecular package of C60 with lecithin has been established. The concentration of C60 presented in liposome is 1.09 × 10-4 mol/dm3. The molecular system of C60-liposome with human cervix cancer cells is irradiated with laser (570 nm, 800 mW), there is obvious biological effect of C60 to huma cervix cancer cells.

Properties of Boron-Substituted Heterofullerenes

On the basis of a succinct description of geometrical configurations for giant fullerenes, the electronic properties and structural distortions of heterofullerenes CN-1B(N = 60, 180, 240, 420, 540, 720, 780) are analyzed by the extended Su-Schrieffer-Heeger model. In comparison with their pristine fullerenes CN, local distortions and mid-gap states are found to occur in boron-doped giant fullerenes.

Electrical Conductivity of the Two-Dimensional Half-Filled Hubbard Model

The electrical conductivity of the one-band Hubbard model on a two-dimensional square lattice at half-filling is studied through the grand canonical quantum Monte Carlo method. Our results support that there exists an insulator-to-metal transition for the half-filled Hubbard model at high temperature.

Peierls Instability in Giant Fullerene

The John-Teller effect of the giant fullerene (GF) is studied. We find that in the giant fullerenes, the C-C bonds are dimerized, binding energies are decreased, energy gaps are enlarged, and the symmetries are reduced in the metallic GF but not in the semiconducting GF. The dimerization patterns of these onions are presented. The distortions decrease as the number of carbon atoms on the GFs increases.

Conformation and microstructure of carbon nanofibers deposited on foam Ni

Bundles of pure carbon nanofibers were prepared by catalytic decomposition of acetylene on foam Ni. The morphological and structural characteristics of the carbon nanostructures, in the as-prepared state, were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HTEM). A special conformation of carbon nanofibers composed of segmented structures was found among the products by both SEM and TEM observations. Further HTEM examination indicated that the segments were stacked with well ordered graphite platelets arranged perpendicular to the axis of the filaments.

Bosonization and Random-Phase Approximation of the Interacting Fermions in High Dimensions

The random-phase approximation (RPA) of interacting fermions is recast into a bosonized form and the RPA results are rederived by the standard bosonization method, which shows that there is a natural connection between bosonization and RPA.

General Jahn-Teller potentials with many electrons

The present paper investigates the Jahn-Teller theory for the case that the degenerate molecular energy level is occupied by many electrons. The Oepik-Pryce treatment and the isostationary function method are used to determine the structure of the Jahn-Teller potential, whose symmetric properties are discussed. Examples are given for ? ? (?1 + ?2) Jahn-Teller problems.

Jahn-Teller effect and superconducting mechanism of the hole-doped C60 solid

A possible superconducting mechanism of the hole-doped C60 solid is discussed. Under the assumption that the superconductivity results from the strong coupling between electrons at Fermi surface and intramolecular vibrations, a simple expression for the electron-phonon coupling parameter λ is derived. The related transition temperature is estimated and can be much greater than that of the alkali-metal-doped C60 solid.

Electron-Phonon Vertex Corrections and Superconductivity in Alkali-Metal-Doped C60 Solids

The narrow conduction band of C60 leads to the breakdown of the Migdal theorem and the McMillan formula is no longer applicable. In this letter, the second-order electron-phonon vertex correction is considered to explain the superconductivity in doped C60 solids and the transition temperature Tc thus obtained is in accordance with the experimental results.

High Yield Synthesis of Bucky Tubules and Bucky Onions

The bucky tubules and bucky onions are synthesized in macroscopic quantity with high yield by modified Kratschmer-Lamb-Fostiropoulos-Huffman method. Besides ordinary concentric bucky tubules, also are observed abnormal nonconcentric multilayer graphitic tubules with varying layer spacings. The curved graphitic tubules are observed, showing the tendency to form torus. Under appropriate helium pressure, about half of the synthesized product is the multi-shell bucky onions, polyhedral in shape in accord with the theoretical calculation.