联合应用循环伏安法和表面等离子体振子共振法测量巯基捕收剂与金表面的相互作用

表面等离子体振子共振(SPR)光谱法与循环伏安法相结合已成功用于研究乙基黄药、庚基黄药、二硫代磷酸盐和丙基三硫代碳酸盐浮选捕收剂与金表面之间的相互作用。在这些巯基捕收剂与金相互作用的电位区内,可获得易于测量的响应,这四类捕收剂有不同的SPR最大值,烷基链越长,SPR响应越高,三硫代碳酸盐的响应值最大。在非常阳极和阴极电位下,SPR响应值与电流密度响应值之间有相当大的差别。可以指出,在低至-300mV(相对标准氢电极电位)电位下,这类巯基捕收剂仍能被吸附。

A Multifunctional Chiral Metasurface with Asymmetric Transmission and Linear-Polarization Conversion

In this paper,a multifunctional chiral metasurface is presented to achieve asymmetric transmission(AT)and linear-polarization conversion(LPC).The designed metasurface consists of a cross swords-like shape and two holes in the lower side of the unit cell.In the frequency band from 8.3 GHz to 10.4 GHz,AT is realized with more than 90%efficiency and the same chiral metasurface transforms linear polarized wave into its orthogonal counterpart with high efficiency.For LPC,the polarization conversion ratio(PCR)is greater than 95%.The proposed metasurface is stable against the incident angles of striking electromagnetic(EM)waves up to 60°for both operations of AT and LPC.

光学免疫传感器的生物传感研究

正在研制的表面等离子体振子共振免疫传感器，用于测量血清中的抗原和抗体的迅速结合，它的共振灵敏度比光学技术的灵敏度高达７倍．所以它是一种新型的生物传感器技术、具有广泛的应用前景．

Raman and Infrared Spectra for All-trans-astaxanthin in Dimethyl Sulfoxide Solvent

The Raman and infrared spectra of all-trans-astaxanthin （AXT） in dimethyl sulfoxide （DMSO） solvent were investigated experimentally and theoretically. Density functional cal-culations of the Raman spectra predict the splitting of the υ1 band into υ1-1 and υ1-2 compo-nents. The absence of splitting in Raman experimental spectra is ascribed to the competition between the two symmetric C=C stretching vibrations of the backbone chain. The υ1 band is very sensitive to the excitation wavelength： resonance excitation stimulates the higher-frequency υ1-2 mode, and off-resonance excitation corresponds to the lower-frequency υ1-1 mode. Analyses of the intramolecular hydrogen bonding between C=O and O-H in the AXT/DMSO system reveal that the C4=O1...H1-O3 and C4＇=O2...H2-O4 bonds are strengthened and weakened, respectively, in the electronically excited state compared with those in the ground state. This result reveals significant variations of the AXT molecular structure in different electronic states.

Resonance Raman Study of Aggregated Meso-tetra（4-pyridinium）porphyrin Diacid

Resonance Raman spectra of aggregated meso-tetra（4-pyridinium）porphyrin diacid （H8TPyP^6＋） were studied with excitation near the exciton absorption bands of 470 nm. The UV-Vis absorption and resonance light scattering spectra of HsTPyP^6＋ monomers and aggregates were also measured. The observed Raman bands of monomeric and aggregated HsTPyP^6＋ were assigned on the basis of the observed deuteration shifts and by comparing with the Raman spectra of analogous porphyrin diacids. Aggregation causes moderate downshifts （2-6 cm^-1） for high-frequency modes involving the in-plane CC/CN stretches of the porphyrin core and a dramatic upshift （12 cm^-1） for the out-of-plane saddling mode of the porphyrin ring. The structural changes induced by aggregation and the possible hydrogen bonding interaction between the HsTPyP^6＋ molecules in the aggregate are discussed based on the spectral observations.

Approach to Perturbative QCD Results in Transition Amplitudes of NucleonNegative-Parity Resonances

The scaling behaviors of the nucleon resonance transition amplitudes from perturbative QCD (PQCD) are utilized to parametrize the amplitudes of the first negative-parity nucleon resonance . Our analysis indicates that the constraints of the transition amplitude for the resonance at the limit by QCD sum rule calculations are not applicable at a moderate range of compared with the present available data if the contribution of is dominant in the limit.

Using sensitive surface plasmon resonance to detect binding of peptide molecules and immobilized vancomycin

To perform the mechanism study of special association for vancomycin and D-Ala-D-Ala-containing peptides on the interface of solution and self-assemble monolayer, the binding between vancomycin and pentapeptide （Lys-Lys-Gly-D-Ala-D-Ala） was investigated by flow injection surface plasmon resonance （FI-SPR） and flow injection quartz crystal microbalance （FI-QCM）. To facilitate the formation of a compact vancomycin adsorbates layer with a uniform surface orientation, vancomycin molecules were attached onto a preformed alkanethiol self-assembled monolayer. By optimizing the conditions for the binding between Lys-Lys-Gly-D-Ala-D-Ala and vancomycin on the assembled chip, the detecting limit of Lys-Lys-Gly-D-Ala-D-Ala was greatly improved （reaching 0.5 ×10^- 6 mol/L or 7.5 × 10^-12 mol）. The equilibrium constant of the association of Lys-Lys-Gly-D-Ala-D-Ala with vancomycin was also obtained （KAds=5.0×10^4 L/tool）.

Electroproduction of Roper Resonance in a Meson Cloud Model

The Q^2 dependencies of Roper resonance (N~* (1440)) helicity amplitudes have been discussed based on twoassumptions:(i) the Roper resonance is an excitation of one of the three quarks,and (ii) the quarks are surrounded bya pion-meson cloud.Our study shows that the mixing of the ground state in the Roper wavefunction caused by the pionmeson cloud together with the pion meson cloud itself is crucial for the predictions of the photoproduction amplitudesof the Roper resonance.It is found that our model can give a good description for the helicity amplitudes of the Roperresonance comparing with the experimental measurement.

Study of Nonpolaritons in a Kerr Nonlinear Optical Resonator

We find that in a Kerr nonlinear optical resonator, the photon system possesses a new kind of quasiparticle, the nonpolariton. The existence of nonpolaritons should be testified by observing the energy density dependence of the velocity and squeezing of nonpolaritons. As we have investigated, the transition energy density of a Kerr nonlinear optical resonator is larger than that of a normal state.

Research progress of surface plasmon resonance technology in drug discovery

Surface plasmon resonance(SPR)technology is a powerful and sensitive tool for investigating molecular interactions.Technical improvements in recent years have brought new functionality to SPR apparatuses that can be widely applied at multiple stages of the drug discovery process.The technology allows users to conduct ligand fishing and offers rich and in-depth information regarding the affinity,specificity,kinetics,concentration and identification of covalent/allosteric/competitive binding behaviors.The present review highlights the principle,sample types,detection ranges,experimental methods,strengths,limitations,and the latest research progress on the application of SPR technology in the drug discovery process.

Modulation of Fano resonances in symmetry-broken gold-SiO_2-gold nanotube dimers

Fano resonances in the symmetry-broken gold-SiO2-gold(BGSG)nanotubes and the associated dimers have been investigated based on the finite element method.In the BGSG nanotube,the symmetry breaking induced the interactions of the inner gold core and outer gold nanoshell plasmons of all multipolar orders and hence the red-shifts of the plasmon resonance modes and the enhanced quadrupole mode peaks were observed.The interference of the quadrupole mode peak with the subradiant dipole mode caused a Fano-dip in the scattering spectrum.By increasing the core offset-value in the BGSG nanotube,the Fano dip with low energy showed a red-shift and became deeper.Unexpectedly the plasmon coupling between a GSG nanotube and a BGSG nanotube can lead to two strong Fano dips in the scattering spectra of the dimer.It was further noted that the thin side of the BGSG nanotube located at two sides of the dimer gap can lead to the strong near-field coupling between two BGSG nanotubes and hence a deeper and broader Fano dip.

Recent advances in biological detection with magnetic nanoparticles as a useful tool

Magnetic nanoparticles have emerged as a powerful tool for magnetic resonance imaging, biodetection, drug delivery, and hyperthermia. This review focuses on the biological detection of magnetic nanoparticles as well as their physicochemical properties. Substantial progress in the sensitivity of detection has been made by developing variety of methods. Five applications of magnetic nanoparticles in biological detection are discussed in this review: magnetic separation, magnetic sensing, magnetic manipulation, magnetic catalysis, and signal enhancer for surface plasmon resonance(SPR). Finally, some future trends and perspectives in these research areas are outlined.

Electronic Structure of Helium Atom in a Quantum Dot

Bound and resonance states of helium atom have been investigated inside a quantum dot by using explicitly correlated Hylleraas type basis set within the framework of stabilization method.To be specific,precise energy eigenvalues of bound 1sns(~1S^e)(n=1-6)states and the resonance parameters i.e.positions and widths of^lS^e states due to 2sns(n=2-5)and 2pnp(n=2-5)configurations of confined helium below N=2 ionization threshold of He^+have been estimated.The two-parameter(Depth and Width)finite oscillator potential is used to represent the confining potential due to the quantum dot.It has been explicitly demonstrated that the electronic structural properties become sensitive functions of the dot size.It is observed from the calculations of ionization potential that the stability of an impurity ion within a quantum dot may be manipulated by varying the confinement parameters.A possibility of controlling the autoionization lifetime of doubly excited states of two-electron ions by tuning the width of the quantum cavity is also discussed here.

Multiple Quantum Coherences(MQ) NMR and Entanglement Dynamics in the Mixed-Three-Spin XXX Heisenberg Model with Single-Ion Anisotropy

We analytically investigate Multiple Quantum(MQ) NMR dynamics in a mixed-three-spin(1/2,1,1/2)system with XXX Heisenberg model at the front of an external homogeneous magnetic field B. A single-ion anisotropy property ζ is considered for the spin-1. The intensities dependence of MQ NMR coherences on their orders(zeroth and second orders) for two pairs of spins(1,1/2) and(1/2,1/2) of the favorite tripartite system are obtained. It is also investigated dynamics of the pairwise quantum entanglement for the bipartite(sub)systems(1,1/2) and(1/2,1/2)permanently coupled by, respectively, coupling constants J_1 and J_2, by means of concurrence and fidelity. Then, some straightforward comparisons are done between these quantities and the intensities of MQ NMR coherences and ultimately some interesting results are reported. We also show that the time evolution of MQ coherences based on the reduced density matrix of the pair spins(1,1/2) is closely connected with the dynamics of the pairwise entanglement. Finally, we prove that one can introduce MQ coherence of the zeroth order corresponds to the pair spins(1,1/2) as an entanglement witness at some special time intervals.