Photodiode-Based Chua＇s Circuit with Light Controllability

We present a photodiode-based Chua＇s chaotic circuit that is controllable by light. The proposed circuit consists of an inductor, two passive capacitors, a photodiode-based variable resistor, and a positive feedback trans- conductor with negative nonlinearity. The chaotic dynamics of the circuit were verified by using the simulation program with integrated circuit emphasis analysis using the 0.35 #m complementary metal-oxide-semiconductor process parameters. The gain results （such as the time waveform~ frequency analysis, three-dimensional attractor, bifurcation and Lyapunov exponents diagrams） confirm that the chaotic behavior of the circuit could be controlled by light intensity via the photodiode-based variable resistor.     

A QUANTITATIVE EVALUATION OF ELASTIC WAVE IN SOLID BY STROBOSCOPIC PHOTOELASTICITY

We have developed a method for visually measuring and evaluating stresses emitted from an ultrasonic probe into a model solid similar to the actual material, by using image-processing techniques and stroboscopic photoelasticity. The visualization of wave stress (sound pressure) distribution can be achieved by synthesizing two photoelastic pictures, in which the directions of the principal axes of linear polariscopes are different by 45 degrees. The sound pressure field generated by commercial ultrasonic probes was measured by using the proposed method.     

Zagreb indices of graphs

The first Zagreb index M₁(G) is equal to the sum of squares of the degrees of the vertices, and the second Zagreb index M₂(G) is equal to the sum of the products of the degrees of pairs of adjacent vertices of the underlying molecular graph G. In this paper, we obtain lower and upper bounds on the first Zagreb index M₁(G) of G in terms of the number of vertices (n), number of edges (m), maximum vertex degree (Δ), and minimum vertex degree (δ). Using this result, we find lower and upper bounds on M₂(G). Also, we present lower and upper bounds on M₂(G) +M₂(G) in terms of n, m, Δ, and δ, where G denotes the complement of G. Moreover, we determine the bounds on first Zagreb coindex M₁(G) and second Zagreb coindex M₂(G). Finally, we give a relation between the first Zagreb index and the second Zagreb index of graph G.     

Molecular and electronic structure of zwitterionic diamino-meta-quinonoid molecules

Quantum chemical calculations using molecular orbital (HF, CASSCF) and density functional theory (B3LYP) methods, in conjunction with the 6–311 + + G(d,p) basis set, have been applied to investigate the molecular and electronic structure of two diamino-meta-quinonoid molecules 1a and 2a, each containing a six-membered ring coupled with two exocyclic C = O bonds situated in a meta position, along with two amino substituents (NH₂ and NH-CH₃). It is confirmed that these substituted meta-quinone systems exhibit a zwitterionic structure in which the positively charged N-C-C(H)-C-N subunit, containing the two amino-groups, forms two chemical bonds with the negatively charged O-C-C(H)-C-O subunit. The negative charge amounts to about half of an electron. The charge separation has been approached in terms of geometries, vibrational frequencies, and electronic distribution. The ionization energy for molecule 1a is about 7.8±0.3eV. The quinonoid systems are essentially non-aromatic characterized by the NICS(+1) values of around 1.2 ppm.     

Regioselective Bridging Calix[6]arenes: Synthesis and X-ray Structure of Trisbridged Calix[6]arene

The preparation and characterization of gold nanoparticles (～6 nm in diameter) modified with mono-6-thio-β-cyclodextrin (II) is described. The resulting monolayer-protected gold nanoparticles are water-soluble and more stable. The concentration of II plays a crucial role for the distribution of the modified nanoparticles. When the ratio of concentration of II to HAuCl₄,[II]/[HAuCl₄] ≥ 0.93, a stable gold nanoparticle with uniform distribution and diameter of 6.0 ± 0.9 nm will be obtained. The recognition of modified gold nanoparticles to organic guest molecule is researched. The modified gold nanoparticles can make the electrochemical reduction current of nitrobenzene decrease and can be self-assembled in three-dimensional to form spherical clusters with ligand of methylene green.     

Relativistic Electron Acceleration in a Wake Field Generated by the Intense Femtosecond Laser Interaction with a Mixture Jet of Deuterium Clusters and Molecules

High energy electron acceleration in a wake field generated in the intense ultrashort （30fs） laser pulse cluster gas jet interaction is experimentally demonstrated. Relativistic electrons with energy of 60 MeV were observed. These high energy electrons split into two beams due to the relativistic self-focusing of the laser.     

The Invariant Rings of the Generalized Transvection Groups in the Modular Case

In this paper, first we investigate the invariant rings of the finite groups G ≤ GL(n, F_q) generated by i-transvections and i-reflections with given invariant subspaces H over a finite field F_q in the modular case. Then we are concerned with general groups G_i(ω) and G_i(ω)~t named generalized transvection groups where ωis a k-th root of unity. By constructing quotient group and tensor, we calculate their invariant rings. In the end, we determine the properties of Cohen-Macaulay,Gorenstein, complete intersection, polynomial and Poincare series of these rings.     

Deuterium Clusters Fusion Induced by the Intense Femtosecond Laser Pulse

Neutrons （2.45MeV） from deuterium cluster fusion induced by the intense femtosecond （3Ors） laser pulse are experimentally demonstrated. The average neutron yield 103 per shot is obtained. It is found that the yield slightly increases with the increasing laser spot size. No neutron can be observed when the laser intensity I 〈 4.3 × 10^15 W/cm^2.