Atomic needles

Lieb et al [42], see also [43] see also the review by Freeman and March [44]. Spherical atoms in our terrestrial environment become atomic needles in suflSiciently intense magnetic fields. 

And to bind electrons in a one-dimensional attractive potential is much easier than binding excess electrons to an almost spherical atom. Whereas in the latter case, only one electron can normally be bound in our terrestrial environment to an initially neutral atom, regardless of the atomic number Z, for atomic needles one can bind up to 2Z, as the total number of electrons. Localization around the magnetic field direction now swamps the infiuence of electron correlation for sufficiently intense fields. 

C. The only lerpene-like natural hydrocarbon containing nine C atoms. It is found in East Indian sandalwood oil and also in Siberian, German and Swedish pine-needle oils. It has a rather unpleasant smell, resinifies easily and is difficult to obtain pure. 

Sekatskii S K and Ketokhov V S 1996 Single fluorescence centres on the tips of crystal needles first observation and prospects for application in scanning one-atom fluorescence microscopy Appl. Phys. B 63 525-30... 

Shape anisotropy is related to the magnetostatic energy of a magnet. A needle-shaped sample tends to line the atomic moments along the needle axis and a disk-shaped sample tends to line these moments parallel to the disk surface. 

The reaction of a mixture of 1,5,9-cyclododecatriene (CDT), nickel acetylacetonate [3264-82-2], and diethylethoxyalurninum in ether gives red, air-sensitive, needle crystals of (CDT)Ni [12126-69-1] (66). Crystallographic studies indicate that the nickel atom is located in the center of the 12-membered ring of (CDT)Ni (104). The latter reacts readily with 1,5-cyclooctadiene (COD) to yield bis(COD) nickel [1295-35-8] which has yellow crystals and is fairly air stable, mp 142°C (dec) (20). Bis(COD)nickel also can be prepared by the reaction of 1,5-COD, triethylaluminum, and nickel acetylacetonate. 

The atom probe field-ion microscope (APFIM) and its subsequent developments, the position-sensitive atom probe (POSAP) and the pulsed laser atom probe (PLAP), have the ultimate sensitivity in compositional analysis (i.e. single atoms). FIM is purely an imaging technique in which the specimen in the form of a needle with a very fine point (radius 10-100 nm) is at low temperature (liquid nitrogen or helium) and surrounded by a noble gas (He, Ne, or Ar) at 10 -10 Pa. A fluorescent screen or a... 

In addition to the wet and optical spectrometric methods, which are often used to analyse elements present in very small proportions, there are also other techniques which can only be mentioned here. One is the method of mass spectrometry, in which the proportions of separate isotopes can be measured this can be linked to an instrument called a field-ion microscope, in which as we have seen individual atoms can be observed on a very sharp hemispherical needle tip through the mechanical action of a very intense electric field. Atoms which have been ionised and detached can then be analysed for isotopic mass. This has become a powerful device for both curiosity-driven and applied research. 

Meroquinenine, CgHjjOaN (meroquinene), formed by the oxidation of all four alkaloids and of cinchoninone or quininone and by the hydrolysis of quinenine or cinchenine (p. 489), crystallises from methyl alcohol in needles, m.p. 223-4° (dee.), [ajp -f- 27-5° (H2O). It gives a nitrosoamine, m.p. 67°, and a monoacetyl derivative, m.p. 110°, and can be esterified the ethyl ester hydrochloride has m.p. 165°. When oxidised by chromic acid it yields formic and cincboloiponic acids. On reduction with zinc dust and hydriodic acid, it adds on two atoms of hydrogen forming cincholoipon, CgH jOaN, and when heated with hydrochloric acid at 250-60° gives 3-ethyl-4-methylpyridine ()3-collidine). 

Strychninic Acids fStrychnic Acids). Although strychnine contains two atoms of nitrogen, it behaves as a monoacidic base. Warmed with a solution of sodium ethoxide it takes up a molecule of water, forming strychninic acid, which crystallises in minute needles, m.p. 215°,... 

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