Single-impurity

Ambrose W P and Moerner W E 1991 Fluorescence spectroscopy and spectral diffusion of single impurity molecules in a crystal Nature 349 225-7... 

Basche T and Moerner W E 1992 Optical modification of a single impurity molecule in a solid Nature 355 335-7... 

Unfortunately, both EEEM and EIM microscopes require a conducting sample, usually metaUic, capable of being fashioned into a very tine point. The microscopes are used for study of crystal defects, purity, and, with EIM, the identification of single impurity atoms. 

Result quoted in ref.2 referring to a single impurity calculation including the first shell of neighbours. 

Similar calculations were carried out for the single impurity systems, niobium in Cu, vanadium in Cu, cobalt in Cu, titanium in Cu and nickel in Cu. In each of these systems the scattering parameters for the impurity atom (Nb, V, Co, Ti or Ni) were obtained from a self consistent calculation of pure Nb, pure V, pure Co, pure Ti or pure Ni respectively, each one of the impurities assumed on an fee lattice with the pure Cu lattice constant. The intersection between the calculated variation of Q(A) versus A (for each impurity system) with the one describing the charge Qi versus the shift SVi according to eqn.(l) estimates the charge flow from or towards the impurity cell.The results are presented in Table 2 and are compared with those from Ref.lc. A similar approach was also found succesful for the case of a substitutional Cu impurity in a Ni host as shown in Table 2. 

A.N. Andriotis, J.S. Faulkner and Yang Wang, Single impurity calculations using the quadratic Korringa-Kohn-Rostoker method , Solid State Commun. 84 267 (1992). 

In the two rows for TLC, the legends total impurities and single impurity are reversed. 

The observed value of the density of a sample is sometimes presented as evidence of its purity. Assuming the sample contains a single impurity, equation (1.10) can be solved for p - pc... 

Single (or multiple) electrons or holes can be bound locally to a small semiconductor nanostructure or to a single impurity in a solid. The resulting discrete energy levels can be used to define a spin qubit. Coherent control and read-out... 

Sautet P, Joachim C (1988) Electronic transmission coefficient for the single-impurity problem in the scattering-matrix approach. Phys Rev B 38 12238... 

In general, limit tests are quantitative or semi-quantitative tests particularly put forward to identify and control invariably small quantities of impurity that are supposed to be present in a pharmaceutical substance. Obviously the amount of any single impurity present in an official substance is usually small, and therefore, the normal visible-reaction-response to any test for that impurity is also quite small. Hence, it is necessary and important to design the individual test in such a manner so as to avoid possible errors in the hands of various analysts. It may be achieved by taking into consideration the following three cardinal factors, namely ... 

Note According to Chevron Phillips Company s (2005) Technical Data Sheet, 99.0-99.4 wt % / -heptane (pure grade) contains the following components c/s-l,2-dimethylcyclopentane -1- methyl-cyclohexane (< 1 wt %), /rafl5-l,2-dimethylcyclopentane (< 0.25 wt %), 3-methylhexane (< 0.25 wt %), sulfur content (< 1 wt %), and the largest other single impurity at a concentration of (<0.15 wt %). 

A. Not more than 0.1% of any single impurity determined by the following method. Carry out the method for liquid chromatography, Appendix III D, using the following solutions in the mobile phase. Solution (1)... 

Impurities Total, ideally, <2% with no single impurity >0.5%... 

To achieve s=97% purity, with no single impurity >1.5%, except up to 10% dimer as determined by the reversed phase HPLC conditions set out in 1.06. The purification is to be achieved by Reversed Phase Preparative HPLC using a 110 mm DAC column packed with 10 m C8 100 A to a length of approximately 25 cm. The product will be purified by gradient elution using the Guideline Purification Strategy attached. 

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