[en] A coupled extended Lotka-Volterra lattice and a special Toda lattice are derived from the existing bilinear equations. Starting from the corresponding bilinear Baecklund transformation, Lax pairs for these two differential-difference systems are obtained. Furthermore, an infinite number of conservation laws for the differential-difference equations are deduced from the Lax pairs in a systematic way

[en] We have calculated the electronic structure and optical properties of Wurtzite structure AIN under different high pressure with generalized gradient approximation (GGA) in this paper. The total energy, density of state, energy band structure and optical absorption and reflection properties under high pressure are calculated. By comparing the changes of the energy band structure, we obtained AIN phase transition pressure for 16.7 GPa, which is a direct band structure transforming to an indirect band structure. Meanwhile, according to the density of states distribution and energy band structure, we analyzed the optical properties of AIN under high-pressure, the results showed that the absorption spectra moved from low-energy to high-energy. (authors)

[en] An integrative D-dot monitor is designed to measure high voltage pulse in transmission line. The monitor which consists of base, airproof BNC connector, probe shell, insulation, probe and connecting rod is located on the outshell of transmission line. Monitor assemblies are coaxially connected by thread, resulting in compaction of configuration and integrality in dis-mounting or mounting. An airproof BNC connector and a seal packing ring of oxygen free copper are used to get good sealing performance and veracity, meanwhile their low elasticity leads to high accuracy of measurement. Low ground capacitance of monitor is designed to get good high-frequency response. Simulation by OrCAD/Pspice is taken, with good signal-to-noise ratio and rising time. Results of simulation on electrostatic field by CST show that the monitor is safe to measure 1 MV high voltage. Results of calibration and experiment show that the integrative D-dot monitor can response to signals with rise time of several tens of nanoseconds, which could fulfill our diagnostic requirement. (author)

[en] Objective: To study the relationships between dynamic changes of the hippocampus metabolites, cognitive impairment and ultrastructural changes of hippocampus in rats during the initial 4 weeks after 6 MV X-ray whole-brain irradiation. Methods: 65 rats were randomly divided into foul groups as sham control (n=5), 10 Gy, 20 Gy and 30 Gy groups (n=20). The learning and memory ability was measured with the Y maze test 4, 8 weeks, 2, 6 months after irradiation. ¹H-MRS was performed after 2 or 4 weeks' brain irradiation. The ultrastructural changes of the hippocampus were observed by electronic microscope. Results: The learning and memorizing ability of irradiation groups was significantly different from that of control group. Compared with control group, the NAA/Ct and Cho/Cr ratio in the left hippocampus in 10 Gy, 20 Gy and 30 Gy groups at 2 weeks and 4 weeks decreased significantly. Neuronal mitochondria edema, endothelial cells swelling and lamina dissociation in myelin sheath were demonstrated in various degrees by electromicroscope at 4 weeks following whole brain irradiation. Conclusions: ¹H-MRS can be used to non-invasively monitor the metabolic changes, both quantitatively and dynamically, of the irradiated rat brain, ¹H-MRS is superior to MRI in detecting early abnormality of the brain. The NAA/Cr and Cho/Cr ratio in irradiated hippocampus could reflect the severity of the brain injury to some extent. (authors)

[en] Solutions of a noncommutative nonisospectral Kadomtsev-Petviashvili equation are given in terms of quasiwronskian and quasigrammian respectively. These solutions are verified by direct substitutions. Dynamics of some obtained solutions are illustrated. (general)

[en] In this Letter, we present multi-soliton solutions to a higher order Ito equation and give a strict proof by pfaffian identities. To a certain point, for soliton equations having 3-soliton solutions, pfaffian technique provides us an approach to determine whether soliton equations have multi-soliton solutions or not

[en] This paper analyzes the distribution and correlation of electrical field and magnetic field located at the emission domain in the solenoid for the high power foil less diode using over-mode microwave device based the single electronic moving equations. It is confirmed that the electronic beam transmission efficiency is correlated with the reflux. The results from experimental research indicate that distinct power efficiency was explicated for the emission electronic beam from foil less diode with different radius cathode when the guiding magnetic field inside the magnetic solenoid was bigger. When the beam radius was 48 mm the electronic beam transmission efficiency was more than 95%, when the beam radius was more than 90 mm the efficiency was smaller than 75%. (authors)

[en] NaYF₄:Yb³⁺, Er³⁺ nanoparticles were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized with SiO₂-NH₂ layer, these NaYF₄:Yb³⁺, Er³⁺ nanoparticles can conjugate with activated avidin molecules (activated by the oxidation of the oligosaccharide chain). The as-formed NaYF₄:Yb³⁺, Er³⁺ nanoparticles, NaYF₄:Yb³⁺, Er³⁺ nanoparticles functionalized with amino groups, avidin conjugated amino-functionalized NaYF₄:Yb³⁺, Er³⁺ nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), UV/Vis absorption spectra, and up-conversion luminescence spectra, respectively. The biofunctionalization of the NaYF₄:Yb³⁺, Er³⁺ nanoparticles has less effect on their luminescence properties, i.e., they still show the up-conversion emission (from Er³⁺, with ⁴S_3/2^→4I_15/2 at ∼540 nm and ⁴F_9/2^→4I_15/2 at ∼653 nm), indicative of the great potential for these NaYF₄:Yb³⁺, Er³⁺ nanoparticles to be used as fluorescence probes for biological system.

[en] Cobalt hydroxide in α-form (α-Co(OH)₂) is an attractive electrocatalyst for oxygen evolution reaction (OER). Traditional preparation of α-Co(OH)₂ nanosheets often leads to a packing morphology after synthesis or post electrode fabrication, which severely limits the exposure of surface active sites. In this work, we report the synthesis of a self-supported 3D flower-like structure consisting of 2D α-Co(OH)₂ nanosheets through a metal-organic-framework (MOF)-mediated synthetic method. We found that the formation of MOF intermediates can produce dispersive α-Co(OH)₂ nanosheets with a stable 3D hierarchical structure which can effectively avoid the packing of individual nanosheets. The developed α-Co(OH)₂ nanosheets exhibit an obviously enhanced OER activity in comparison with the nanosheets prepared with traditional method. The prepared α-Co(OH)₂ nanosheets have been well characterized and their formation mechanism is proposed.

[en] In this Letter, we first present the Wronskian solutions to the Baecklund transformation of a special two-dimensional lattice by Blaszak and Szum [M. Blaszak, A. Szum, J. Math. Phys. 42 (2001) 225] and then derive the coupled system for the Baecklund transformation through Pfaffianization. It is shown the coupled system so obtained is nothing but the Baecklund transformation for the coupled system of the special lattice [G.F. Yu, C.X. Li, J.X. Zhao, X.B. Hu, J. Nonlinear Math. Phys. 12 (2005) 316]. This implies that Pfaffianization and Baecklund transformations are commutative for the special lattice. Moreover, since the two-dimensional Toda lattice equation forms one part of the special lattice, it is obvious that the commutativity is also applicable to it