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Based on land-use database updated with the survey of 1996, 2000, 2004 and 2008, this paper analyzed the land-use changes in the typical transect area along National Highway 106 with the aid of GIS technology and quantitative models. The results showed that arable land had been continuously decreased from 1996 to 2008, with a loss of 65.85×10 3 hm 2 and an average decrement of 5.49×10 3 hm 2 per year, and the loss in northern areas was larger; garden land and woodland were gradually centralized to the predominance area with an increment of 25.73×10 3 hm 2 and 22.37×10 3 hm 2 , respectively; residential and industrial land increased year after year, and the transportation land showed the equalized developing spatial pattern; the increment of construction land and encroachment on arable land in the area were deeply influenced by the national macroscopic land-use policies, the rapid advance of urbanization and the development level of the regional economy. Through this case study, it is suggested that differential land-use policies should be adopted to create good environmental conditions to guarantee food security and to promote the economic development.

We study the coherent exciton transport of continuous-time quantum walks (CTQWs) on Erdos–Renyi networks. We numerically investigate the transition probability between two nodes of the networks, and compare the classical and quantum transport efficiency on networks of different connectivity. In the long time limiting, we find that there is a high probability to find the exciton at the initial node. We also study how the network parameters affect such high return probability.

This paper derives the formulas to determine T c by the long-range phase coherence conditions in quantum and classical XY -models, solves BCS gap equation, explains uniformly the experimentally observed doping dependences of T c , the temperature of opening the pseudogap T * , the gap at 0 K Δ (0), 2 Δ (0)/ T * , 2 Δ (0)/ T c , and the superfluid density in the high- T c cuprates, and makes four predictions.

This paper derives a generic Tc formula by using the long-range phase coherence condition in quantum phase fluctuation of the order parameter. Taking the two-local-spin-mediated interaction as a Cooper pair potential, and using BCS gap equation and the Tc formula, this paper explains some basic experimental findings of both the high-Tc singlet and the low-Tc triplet superconductors, i.e. La2−xSrxCuO4 (LSCO) and Sr2RuO4, and predicts that the high-Tc superconductivity should also be discovered for extra-underdoped LSCO.

The theory in this paper concludes that the gap along Gamma-X in the CuO 2 plane of B2212 should be zero.

This paper shows that in YBCO and BSCCO there are five kinds of waves for the order parameter, d, pl, p2, s and extended s, and explains six important experimental facts.

We show that the anisotropic gap in the CuO 2 plane of high- T c cuprates is s ′ + i d ′, s ′ and d ′ being the extended s -wave and d -wave, respectively, and the maximum value of the gap is at the angle Φ = 12.2° at any fixed temperature, Φ being the angle from the CuO bond in the CuO 2 plane. Because the corresponding experimental maximum value is at Φ ⋍ 13° as well, it may be possible that the high T c in the cuprates is due mainly to the two-local-spin-mediated interaction.

This paper shows that the observed high Tc, the observed nesting Fermi surface, and the directly observed eight properties of the gap on the CuO2 plane in the high-Tc cuprates, including the gap anisotropy, the zero gap at T

From the numerical solution of the Eliashberg equation for more than a hundred model spectra of the Eliashberg function with single peak, it is concluded that the high T c superconductivity can in principle be caused by the phonon mechanism under the condition λ T c , the high frequency phonon is important and the low frequency phonon is negligible.

This paper shows that high local spin benefits superconductivity, and gives a conjectured explanation for the high T c in Fe 1− x S. This paper points out that the search for high- T c superconductive materials should extend into antiferromagnetic conductors, and the combination of the two-local-spin-mediated interaction and the phonon-mediated interaction may be a superconductive mechanism for many kinds of materials.

Using Abrikosov's pseudo-fermion method, Larsen's technique, and Cheung and Mattuck's procedures, this paper gives a new solution for exchange scattering with local spin S = 1 in dilute alloys, and show that the simple s-d model can solve the problem contradicting charge neutrality.

The measurements of the energy gap at different locations on the CuO 2 plane in BSCCO, YBCO, and TBCCO by STM indicate that the different locations can have different values of gap, which is called by us the local gap. The spread of the local gap values is from 27 to 50 meV at 6.4 K. This paper interprets the cause of formation of the local gap and explains its three features using the two-local-spin-mediated interaction (TLSMI) mechanism of the superconductivity in the high-T c cuprates and the fluctuation of antiferromagnetic(AF) short range order.

We have deduced from muffin-tin orbitals band structure calculations that there is sizeable hybridization between the non-bonding d state of the transition metal atom and the p state of the chalcogen. Through an increase (a decrease) in hybridization effected by lattice distortions, attractive interactions at metal atom sites for a pair of electrons (holes) in the conduction band result and give rise to charge density waves. We calculate the dependence of this attractive interaction λ on the fractional ionic character of the metal-chalcogen bond. Calculated physical quantities and behaviors are in agreement with experimental data.

An orthogonal and complete set for relative motion of four-electron 2-D system in strong magnetic field is given, the energy of ground state of relative motion is calculated. This paper also calculates the energy of ground state whose maximum of single electron angular momentum is limited by the degeneracy under a given magnetic field, obtains the energy minimums corresponding to a fractional quantized Hall effect of 2 5 , 2 7 , and from it the physical meaning of “magic number” is interpreted.

The scattering of electrons in the superconducting phase is calculated including the exchange of magnetic impurity pairs. Providing that the RKKY coupling favors ferromagnetic alignment of the impurity spins, the superconducting transition temperature is found to exhibit a re-entrant behavior as a function of the impurity concentration.

This paper presents a limitation on the eigenvalues of angular momentum with the degeneracy of Landau level. According to the limitation a series of wave functions are given. In the case of few-body our calculations show that the Laughlin's Jastrow function are correct. This paper suggests wave functions to explain the fractionally quantized Hall effect.

Using the Eliashberg equation in the Matsubara representation, the calculation of Tc for the PdH and PdD systems is performed under two schemes, and the inverse isotope effect is restudied. We conclude that the inverse isotope effect derives from the harmonicity of the lattice in most cases. In fact, there are more experiments to support our results.

Based on Weber's and Mattheiss's spectra, Frohlich's electron-phonon interaction and the Jahn-Teller effect, this paper concludes that the high Tc superconductivity of Ba2YCu3O7 originates in a phonon mechanism.

A superconductivity theory is set up in this Communication, which considers the effective retardative attractive interaction mediated by LO phonon under the condition of transition of small polaron into large polaron. It has been discovered that high Tc superconductivity will be caused in the condition of existence of degenerate high frequency LO phonon spectra. The high Tc superconductivity of YBaCuO and similar MO systems are caused by the exchange of LO phonon between two Frohlich polarons.

An electron scattering from interacting magnetic impurities is found to exhibit a T − divergence in the resistance at low temperatures. Together with the normal T 5 phonon contribution, a concentration x of magnetic impurities with a ferromagnetic RKKY interaction yields a resistivity minimum with a characteristic temperature T min σx 1 3 . The theory provides a good description of data on Fe x TaSe 2 and similar compounds, in distinct contrast to the Kondo effect.