Intermediate coupling model description of55Fe and57Fe

The properties of the negative parity states of⁵⁵Fe and⁵⁷Fe are investigated in the framework of the intermediate coupling model. In the model, a neutron or a quasineutron is coupled to anharmonic vibrations of the core. Anharmonicities of the vibrations are estimated through the observed properties of the core. Energy levels, spectroscopic factors and electromagnetic properties have been calculated. The results of the present calculations are also compared with available experimental results and other theoretical results. The model reasonably accounts for many of the properties of the low-lying states.     

Effect of radiative cooling on collapsing charged grains

The effect of the radiative cooling of electrons on the gravitational collapse of cold dust grains with fluctuating electric charge is investigated. We find that the radiative cooling as well as the charge fluctuations, both, enhance the growth rate of the Jeans instability. However, the Jeans length, which is zero for cold grains and nonradiative plasma, becomes finite in the presence of radiative cooling of electrons and is further enhanced due to charge fluctuations of grains resulting in an increased threshold of the spatial scale for the Jeans instability.     

Automatic Structure Determination of Organic Molecules： Principle and Implementation of the LSD Program

The LSD (Logic for Structure Determination) program gener-ates organic molecular structures from 1D and 2D NMR data without resorting to chemical shift databases. Its use in the res-olution of natural product structure determination problems has been already reported in the literature. This paper describes how data and structures are internally represented and pro-cessed by LSD to build solution structures.     

A calcium-selective optrode based on fluorimetric measurement of membrane potential

An ion-selective optrode for the continuous determination of calcium ions is presented. It is based on measurement of the fluorescence intensity of a potential-sensitive dye (the C-18 ester of rhodamine B) incorporated into a lipid membrane constructed by the Langmuir-Blodgett film technique. The membrane potential depends on the calcium ion concentration in the sample solution, when a calcium-selective ionophore (ETH 1001) is incorporated into the lipid membrane. The fluorescence of the potential-sensitive dye is reduced with increasing calcium ion concentrations. Interferences by other cations can be compensated for by using a reference optrode. The relation between the negative logarithm of the calcium ion concentration and the decrease in relative fluorescence is linear over the range 0.1–10 mM calcium and can be described by an optical “Nernst” equation. The selectivity factors over magnesium, sodium and potassium are better than 1×10⁵ when the reference optrode is used. The maximal signal change caused by 10 mM calcium ion is ?8%. The membranes are stable for more than six months when stored in the dark. The analytical data are compared with those obtained with potassium- and sodium-selective optrodes, and the photophysical principles underlying the selective and unselective responses are discussed.     

Comparison between the growth of gold particles onto MgO and amorphous carbon substrates by in situ electrical conductance measurements

The sheet conductance of gold condensates on MgO anda-C is expressed in terms of granulometric quantities. This expression enables us to follow the evolution of metal repartition on its substrate during the gold evaporation. The difference between the growth modes of these gold layers on MgO and ona-C is explained by the predominance of respectively nucleation and coalescence phenomena     

Determination of glucose in wine and fruit juice based on a fibre-optic glucose biosensor and flow-injection analysis

A flow-injection system for the determination of glucose in various samples using a glucose biosensor based on an oxygen optrode with immobilized glucose oxidase (GOD) is described. The consumption of oxygen was determined via dynamic quenching of the fluorescence of an indicator by molecular oxygen. GOD was adsorbed on a sheet of carbon black and cross-linked with glutaraldehyde. Carbon black was used as an optical isolation to protect the optrode from interference from ambient light and sample fluorescence. The system is linear for 0.1–500 mM glucose, with an r.s.d. of 2% at 100 mM (5 measurements). The application of the system to glucose in wine and fruit juice is demonstrated. It was possible to analyse up to 60 samples per hour. The enzyme optrode was stable for more than 400 h in continuous use and was easily maintained.