MCM-41-supported bidentate phosphine palladium(0) complex: a highly active and recyclable catalyst for the Sonogashira reaction of aryl iodides

The first MCM-41-supported bidentate phosphine palladium(0) complex has been prepared. This complex is a highly efficient catalyst for Sonogashira reaction and can be reused at least 10 times without any decrease in activity.     

Quantum State Sharing of an Arbitrary Three-Atom State by Using Five-Atom Cluster State in Cavity QED

We present a scheme for implementing the deterministic quantum state sharing of an arbitrary three-atom state by using a five-atom cluster state and a Bell-state in cavity QED. In the scheme, it does not involve Bell-state measurement and only needs to perform the single-atom measurements. Our scheme is not sensitive to both the cavity decay and the atom radiation, which is of importance in view of decoherence.     

Nonclassicality and Decoherence of the Variable Arcsine State in a Thermal Environment

A kind of non-Gaussian state—variable arcsine state is studied by using the input-output theories which relate the statistical properties of the output field to those of the input field. The variable arcsine state (VAS) is generated by using a variable beam splitter (BS), which means that the transmissivity (reflectivity) of the BS is adjustable continuously. The nonclassicality is investigated by studying the negativity of Wigner function (WF). It is shown that the variable arcsine state has negative values of WF when transmissivity is not equal to 1 or 0. The decoherence effect of the VAS is then studied by analytically deriving the time evolution formula of WF.     

Surface-enhanced Raman scattering effect of gold nanoparticle arrays: The influence of annealing temperature,excitation power and array thickness

Gold nanoparticle arrays are fabricated for surface-enhanced Raman scattering (SERS) and the effect of the annealing temperature, the thickness of nanoparticle array and the exciting power on the SERS signals are investigated. The particle distribution and particle size are dense and uniform on the glass substrate when the 10 nm gold film was annealed at 250 °C and strong SERS signals for Rhodamine 6G were achieved via a 532 nm excitation with a 10 mW power. The SERS signal at 1650 cm⁻¹ is enhanced more than 10 times as compared to that of the gold film without annealing. The strong SERS behavior of gold nanoparticle arrays may broaden the SERS applications in biomedical and analytical chemistry.     

Efficient Fluorescent Recognition of Carboxylates in Aqueous Media Using Facilely Electrosynthesized Poly(9-Aminofluorene)

A variety of carboxylates were recognized using poly(9-aminofluorene) (P9AF) in the HEPES buffer (pH 7.4), and a proposed possible mechanism was proposed as following. The intermolecular hydrogen bonding interactions resulted in electron transfer between P9AF and carboxylates. P9AF was facilely electrosynthesized in boron trifluoride diethyl etherate and could be used as an efficient fluorescent sensing material for the detection of AcO^?. On binding to AcO^?, fluorescence quenching of P9AF was demonstrated by a maximum 80 % reduction in the fluorescence intensity, while no obvious fluorescence change could be observed in the presence of some other common anions. Some different carboxylates could be recognized at different levels by P9AF. Substituent groups in carboxylates could affect the intermolecular interaction between carboxylates and P9AF. These could be explained by a possible mechanism that hydrogen bonding was the main way of intermolecular interactions between P9AF and carboxylates, which was further confirmed by absorption spectra monitoring and density functional calculations. The significant advantage of this strategy is that it does not require a prequenching procedure and the polymer can be used directly for analyte detection.     

High-Order Hamilton＇s Principle and the Hamilton＇s Principle of High-Order Lagrangian Function

In this paper, based on the theorem of the high-order velocity energy, integration and variation principle, the high-order Hamilton＇s principle of general holonomic systems is given. Then, three-order Lagrangian equations and four-order Lagrangian equations are obtained from the high-order Hamilton＇s principle. Finally, the Hamilton＇s principle of high-order Lagrangian function is given.     

Quantum Hadamard Operators and Their Decomposition Derived by Virtue of IWOP Technique

We introduce the quantum Hadamard operator in continuum state vector space and find that it can be decomposed into a single-mode squeezing operator and a position-momentum mutual transform operator. The two-mode Hadamard operator in bipartite entangled state representation is also introduced, which involves the two-mode squeezing operator and [η〉 ←→｜ξ〉 mutual transformation operator, where [η〉 and ｜ξ〉 are mutual conjugate entangled states. All the discussions are proceeded by virtue of the IWOP technique.     

Luminescence of the compounds Y0.5 − x Li1.5PO4:Eu x

In this paper for the first time, the compounds Y_{0.5 ? x} Li_1.5PO₄:Eu _x (YLP:Eu) were synthesized by the simple method of solid state reaction. The technology takes much time dry low temperature and little time calcined to synthesize rare earth phosphates. Their structures were analyzed by X-ray powder diffraction experiment. The excitation and emission spectra were measured at room temperature. Y_{0.5 ? x} Li_1.5PO₄:Eu _x shows the characteristice emissions of Eu³⁺ (⁵ D ₀-⁷ F _{1, 2, 3, 4} transitions dominated by ⁵ D ₀-⁷ F ₄). Incorporation of Li⁺ ions in the phosphors promote the crystallinity, reduce the amount of Y₂O₃, and lower the cost of production, moreover, transition dominated by ⁵ D ₀-⁷ F ₄ is important for a number of practical applications.     

Environment-Induced Entanglement for a Tripartite System in Non-Markovian Dissipation

We show that entanglement between three two-level atoms can be generated if the three atoms interact with a common structured reservoir, but do not interact directly with each other. Comparing with the results in Markovian case, we find that much higher values of bipartite and tripartite entanglement can be obtained for an initially factorized state of the tripartite system. The maximal value of entanglement depends on the detuning and the strength of relative coupling between the atoms and the reservoir.