Observation of bound-free transitions of the linear Ar...I2(X,v"=0) complex in and above the I2 B-X spectral region

Laser-induced fluorescence and action spectroscopy experiments were performed to identify the origin of the Ar...I(2) continuum signals observed in and above the I(2) B-X spectral region. We have verified that these signals arise from transitions of the linear Ar...I(2) (X,v"=0) complex. The data provides no evidence that the excited state complexes undergo a one-atom caging mechanism when prepared above the I(2)(B) dissociation limit, Ar...I(2) (B)*-->Ar+I+I*-->Ar+I(2)(B,v'). Instead, our results indicate that the continuum signals result from bound-free transitions of the linear Ar...I(2) X,v(")=0) complex to the inner repulsive walls of numerous Ar+I(2)(B,v') intermolecular potentials. The bound-free continuum signal associated with transitions to each Ar+I(2)(B,v') potential spans an energy region >700 cm(-1). We have found that the continuum signals turn-on 250(2)cm(-1) above the corresponding I(2) B-X,v'-0 band origin, and this energy represents the binding energy of the linear Ar...I(2) (X,v"=0) conformer, D(0) (")(L)=250(2)cm(-1).     

Great expectations: Specific lexical anticipation influences the processing of spoken language

Background  

Recently several studies have shown that people use contextual information to make predictions about the rest of the sentence or story as the text unfolds. Using event related potentials (ERPs) we tested whether these on-line predictions are based on a message-level representation of the discourse or on simple automatic activation by individual words. Subjects heard short stories that were highly constraining for one specific noun, or stories that were not specifically predictive but contained the same prime words as the predictive stories. To test whether listeners make specific predictions critical nouns were preceded by an adjective that was inflected according to, or in contrast with, the gender of the expected noun.     

Anomalous atomic hydrogen shock pattern in a supersonic plasma Jet

A two-photon laser-induced fluorescence study on the transport of ground-state atomic hydrogen in a supersonic plasma jet, generated from an Ar-H (2) mixture, reveals an unexpected shock pattern. Whereas both the axial-velocity profile and the temperature profile of hydrogen atoms along the jet centerline can be interpreted in terms of a supersonic expansion of an Ar-H gas mixture, the H-atom density profiles do not satisfy the well established Rankine-Hugoniot relation leading to a nonconservation of the forward flux. The experimental results show that H atoms escape from the supersonic expansion by a diffusion process due to strong density gradients between the core of the jet and its vicinity.     

Experimental and theoretical investigations of the He...I2 rovibronic spectra in the I2 B-X, 20-0 region

The laser-induced fluorescence and action spectra of I2 in a helium supersonic expansion have been recorded in the I2 B-X, 20-0 region. Two features are identified within the spectra. The lower-energy feature arises from transitions between states that are localized in a T-shaped conformation on both the X- and B-state potentials. The higher-energy feature reflects transitions from states that are localized in a linear conformation on the X state to states that have energies that are larger than the barrier for free rotation of the rare gas atom about the I2 molecule on the B-state potential. Ground-state binding energies of 16.6(6) and 16.3(6) cm-1 were determined for the T-shaped and linear conformers, respectively. These spectra are compared to those calculated using the experimentally determined rotational temperatures. Based on the agreement between the experimental and calculated spectra, the binding energies of the J'=0 states with 0 and 2-6 quanta of excitation in the He...I2 bending mode on the B state were determined. Several models for the B-state potential were used to investigate the origins of the shape of the contour of the higher-energy feature in the spectra for He...I2 and He...Br2. The shape of the contours was found to be relatively insensitive to the choice of potential. This leads us to believe that the spectra of these systems are relatively insensitive to the parameters of the B-state potential energy surface and are more sensitive to properties of the halogen molecule.     

Instant nano-hydroxyapatite: a continuous and rapid hydrothermal synthesis

Nano-particle hydroxyapatite (HA) rods, were rapidly synthesised using a three pump continuous hydrothermal process (using a water feed at up to 400 degrees C and at 24 MPa): the product was obtained as a highly crystalline and phase pure material, without the need for an ageing step or subsequent heat treatment.     

ICP-AES法测定色漆可溶性金属含量

用ICP-AES法测定了色漆中的“可溶性”金属铬、镉、铅元素，考察了不同酸度对分析结果的影响，优化了测试条件。进行了回收率和精密度试验。并用原子吸收光谱国标方法进行对照，结果一致。     

Gas sensing with nano-indium oxides (In2O3) prepared via continuous hydrothermal flow synthesis

A rapid, clean, and continuous hydrothermal route to the synthesis of ca. 14 nm indium oxide (In(2)O(3)) nanoparticles using a superheated water flow at 400 °C and 24.1 MPa as a crystallizing medium and reagent is described. Powder X-ray diffraction (XRD) of the particles revealed that they were highly crystalline despite their very short time under hydrothermal flow conditions. Gas sensing substrates were prepared from an In(2)O(3) suspension via drop-coating, and their gas sensing properties were tested for response to butane, ethanol, CO, ammonia, and NO(2) gases. The sensors showed excellent selectivity toward ethanol, giving a response of 18-20 ppm.