andreeva_tia_nauchnyi_angliiskii_iazyk_vypusk_5_slovarminimu

et seq. (et sequentia)	и последующие
focus (pi. foci)	фокус
ib., ibid (ibidem)	там же, в том же месте
i.e. (ed. est)=that is	то есть
in ex. (in extenso)	довольно, полностью
in parvo	в незначительной мере
in re	относительно, по вопросу
in situ	на своем месте
in vitri	в лабораторном сосуде
in vivo	в естественных условиях, на
int.al.(inter alia)	живом организме
	между прочим
in toto	в целом
ipso facto	в силу очевидности, самим
	фактом
locus (pi. loci)	место, месторасположение,
loc. cit	геометрическое место точек
	указанное сочинение
med. (medium)	середина, средний
memo (memorandum)	меморандум
modus operandi	способ действия
mutatis mutandis	сделав соответствующие
N.B. (nota bene)	изменения
	примечание, отметка
nucleus (pi. nuclei)	ядро, ячейка
par example	например
par excellence	преимущественно
pari passu	попутно
per annum	в год

80

per capita	на душу населения
perse	сам по себе, по существу
p.m. (post meridiem)	после полудня
prima facie	на первый взгляд
pro et con (pro et contra)	за и против
pro forms	формально, для вида
prorata	пропорциональный
re,in re	по делу, по вопросу
sui generis	своего рода, своеобразный
terra incognita	незнакомая область
versus (vers, vs)	против, в сравнении с, в зави­
vica versa (v.v.)	симости от
	наоборот
vide infra	см. ниже
vide supra	см. выше
viz (videlicet)	а именно
vulgo	обычно

81

ОБРАЗЦЫНАУЧНЫХТЕКСТОВ’

T e x t 1

Numerical results

То investigate the slope of N(l) described in Eq. (2) for rather small /, the simulation of isotropic fractal systems was performed for a relatively small box of 6(7x б а х 6a. The simulations were carried out using the IMDSapplication, a software-framework for interactive MDsimulation and -visualization in real time. For larger sys­ tems (> 1 0 0 0 particles), a new algorithm based on spatial domain decomposition has been developed in order to im­ prove the performance of the MD-calculations. Based on this algorithm, parallel processing has also been applied. The volume that takes one particle in the most dense sphere package is a 3, where the particles touch each other at the distance of 1.122<r. Here, the potential reached its mini­ mum. Under these conditions, the box should be cast with 216 particles. For the simulation, a lower density was cho­ sen. 150 particles were randomly distributed in the box us­ ing periodic boundary conditions. Because their mutual re­ pulsions and potential energies were very large, the kinetic energy in the molecular dynamics procedure corresponded to a very high temperature. The systems were aged to re­ move the artifacts of the initial conditions.

Afterwards, the system was frozen to an amorphous or glassy state at veiy low temperatures with a simulatedannealing procedure and the coordinates of these particles were stored. To discriminate between next nearest and next-next nearest neighbours, bonds were defined for particles separated by less than 1.15cr. This threshold was slightly larger than the touching distance of 1.122<r. Be-

*} Материалы взяты из современных англоязычных научных жур­ налов

82

cause the two-particle correlation of this frozen system is very small for distances slightly larger than 1.15a, die re­ sultsdidnotchangeby increasingthis valueby a fewpercent

For the box-counting method, cubic boxes with side lengths between 6 a and 54<r were used by concatenating boxes with side lengths of 6 crand 18a. Simultaneously, on three-dimensional cubic lattices with side lengths between 1 and 30 particle distances, bond-percolation clusters were also determined . In Fig. 1(a), logio N(logi0 /) is plotted for both systems. For larger sizes in the isotropic system, die particle occupation (plotted as triangles) begins to bend upwards (for the probability p = 0.385 of the bond accep­ tance) and downwards (for the probability p = 0.380). Only for p=0.3825 does the occupancy curve (plotted as small open circles) follow a more or less straight line. Therefore, p = 0.3825 should be close to p c. Unfortunately, this value as such is meaningless because the number of bonds (280) is significantly smaller than 1296, the maximum theoretical value in the most dense sphere package. Reducing pcby the factor 280/1296 gives a value of 0.08264, which is three times smaller than 0.24881, the value of pc in the threedimensional fractal based on a simple cubic lattice. In comparison, the MD-simulation results of a system with a box-length of 18a and its expansions to 36a and 54a arc shown in Fig. 1(a) as larger circles. There, pc is reduced to the value of 0.350.

T e x t 2

From the History ofthe Computer

The introduction of agriculture revolutionized ancient man's social, economic, and cultural potential. This was the first great step in the evolution of civilization. The more recent Industrial Revolution, vastly increasing man's pro­ ductive capabilities, was the next great step and brought

83

forth our present highly mechanized economic and in­ terdependent social civilization.

Nowadays we have another new kind of revolution, based on machines that greatly increase man's thinking ca­ pabilities of planning, analysing, computing, and control­ ling. Hundreds of millions of computers are already in daily use penetrating almost all spheres of our modem so­ ciety, from nuclear energy production and missile design to the processing of bank checks and medical diagnoses.

The development of mechanical calculating machines made the digital computers necessary. An ordinary arith­ mometer and a desk key calculator have given rise to elec­ tronic digital.computers. Digital computers came into being in the first half of the 17th century. Many outstanding Russian and foreign mathematicians of the time created mechanical calculating devices.

The famous Russian scientist M.VXomonosov com­ piled a lot of calculating tables and several computing de­ vices concerning different fields of science and engineer­ ing.

In 1874 the Russian engineer V.T. Ordner invented a special counter wheel named after him the Ordner's wheel which is used in modem arithmometers and calculators.

P.L. Chebyshev, academician, made a valuable contri­ bution to the field of computing machine. He is known to have many good ideas in mathematics, some of which have been named after him. For example, the Chebyshev's poly­ nomials play a unique role in die field of orthogonal func­ tions. In 1878 he constructed the original computing ma­ chine which was exhibited in Paris. In 1882 P.L. Che­ byshev invented an arithmometer performing automati­ cally multiplication and division. The principle of automati­ zation put into this computing machine is still widely used all over the world when developing die mostmodem computers.

In 1884 Russia began to manufacture computing ma­ chines. In the period of World War I the output of com­ puting machines ceased and was resumed later.

84

T e x t No. 3

Simulation ofMulti-Level Systems

in Amorphous Metals

In crystalline materials any microstructure leading to a perturbation of the translational symmetry represents a lat­ tice defect. Based on this definition it is obvious that in amorphous structures each -atom may be considered as a 'defect' of the structure, i.e., for a more physical characteri­ sation of defects in amorphous structures besides the for­ mal geometrical arguments we have to consider thermody­ namic and elastic properties. Such physical properties are, for example, the stress fields generated by each atom. As shown by Egami et al (1980) in amorphous alloys each atom may be considered as a source of elastic stresses. In these investigations the atoms are treated as centres of dila­ tion or compression in a nearly dense random packed (DRP) glass model. An additional characteristic property of defect structures is the mobility of point-like defects. Such mobile defects are responsible for structural relaxation phenomena and, in the case of ferromagnetic alloys, for magnetic after­ effects and induced anisotropies in particular.

An interpretation of these phenomena has been given previously on the basis of two-level systems by Kronmiiller (1983). Here it has been assumed that in the environment of vacancy-type defects an atom may occupy two energeti­ cally nearly equivalent positions, thus giving rise to relaxa­ tion phenomena by hopping between these two configura­ tions. In contrast to this model Spaepen (1978) as well as Benett et al (1979), using Lennard-Jones potentials in computer built DRP glasses, have suggested that vacancies in amorphous materials are not stable. Also Rivier (1982) suggested that only odd line defects or disclinations should be stable in amorphous material. Generation of a vacancy in these simulated amorphous structures led to a disappear­ ance of die vacancy by a multitude of structural rearrange­ ments. This problem has been reconsidered by Brandt

85

(Brandt 1984, Brandt and Kronmiiller 1983) who has shown that, depending on the range of the interaction po­ tential, vacancy type defects can always he conserved to some extent in amorphous structures. It seems that the presence of these free volumes is a prerequisite of a multi­ tude of diffusional properties or amorphous alloys. In par­ ticular magnetic and elastic relaxation phenomena can be attributed to the reorientation of atom pairs near free vol­ umes. Quantitative analysis of these experimental results (Kronmiiller and Moser 1985) has confirmed that many relaxation phenomena existing over a wide spectrum of ac­ tivation energies correspond to rather localised atomic rear­ rangements, leading to reversible relaxation processes. In computer simulated amorphous structures the presence of such localised rearrangement modes so far has not been detected. Since amorphous structures are characterised by an infinitely large number of metastable states we concen­ trate in the following on those configurations which ,may have only slightly different energies. If such twofold de­ generate atomic configurations are trapped in regions ex­ tending over nearest or next-nearest neighbours we are dealing with a localised two-level system.

T e x t 4

Mesomorphic Order in Polymers with Side Groups ContainingElements ofMesogenic Structure

Recent industrial developments in the field of high modulus fibers have generated a lively interest in polymers with liquid crystalline organization. Such polymers can be roughly divided into three categories: polymers in which the mesogenic element of structure is contained in the backbone of the macromolecule, polymers in which such elements are in the side group, and block and graft copoly­ mers.

86

The correlation between molecular structure and nature of the liquid crystalline order has been a subject of inten­ sive study in the case of block and graft copolymers. How­ ever, such correlations have been little discussed for the first two categories of polymers mentioned above. The ob­ ject of this note is to discuss such correlations for polymers in which the side groups contain elements of mesogenic structure. This discussion will be based on existing litera­ ture data.

It has been pointed out on several occasions that the molecular organization of a mesomorphic monomer can be "locked in" if rapid polymerization were accompanied by extensive cross-linking of the polymer. In such cases the molecular organization prevailing within the mesophase of the monomer was found preserved in the polymeric net­ work down to the minute detail of textural disclinations. The situation is, however, entirely different in the absence of cross-linking at lower polymerization rates. Under such circumstances relaxation occurs and this often leads to phase separation and formation of an amorphous polymer. In some cases a directional (nematic) or layered (smectic) order is developed in the polymer. Rapid precipitation from dilute solution in good solvents of such ordered polymers leads invariably to an amorphous polymer, whereas skilful annealing, swelling, and casting bring back the mesomor­ phic order. This order is not necessarily identical with the order of the initial monomeric mesophase.

T e x t 5

Degradation ofPhenanthrene, Fluorene and Fluoranthene by Pure Bacterial Cultures

Summary. Bacterial mixed cultures able to degrade the polycyclic aromatic hydrocarbons (PAH) phenanthrene, fluorene and fluoranthene, were obtained from soil using conventional enrichment techniques. From these mixed

87

cultures three pure strains were isolated: Pseudomonas paucimobilis degrading phenanthrene; P. vesicularis de­ grading fluorene and Alcaligenes denitrificans degrading fluoranthene. The maximum rates of PAH degradation ranged from 1.0 mg phenanthrene/ml per day to 0.3 mg fluoranthene/ml per day at doubling times of 12 h to 35 h for growth on PAH as sole carbon source. The protein yield during PAH degradation was about 0.25 mg/mg С for all strains. Maximum PAH oxidation rates and optimum spe­ cific bacterial growth were obtained near pH 7.0 and 30° C. After growth entered the stationary phase, no dead, endproducts of PAH degradation could be detected in the cul­ ture fluid.

Introduction. The fate of polycyclic aromatic hydrocar­ bons (PAH) in nature is of great environmental concern due to their toxic, mutagenic, and carcinogenic properties (Kingsbury et al. 1979; Mortelmans et al. 1986; Pahlmann and Pelkonen 1987). Although PAH may undergo photoly­ sis, chemical oxidation, and volatilisation, the major de­ composition process is microbial degradation (Callahan et al. 1979). Consequently considerable research efforts on the microbial degradation of PAH concerning metabolic pathways, enzymatic mechanisms, and genetic control have been made, as reviewed by Gibson (1984), Cemiglia (1984) and Williams (1978). Furthermore the microbial oxidation of PAH containing more than three fused ben­ zene rings to several metabolites has been investigated (Cemiglia et al. 1986; Hammel et al. 1986; Heitkamp and Cemiglia 1987). However, information on microbial biodegradability of these PAH when used as sole carbon source is lacking.

This paper deals with the isolation and characterization of different bacterial strains which were able to completely mineralize the PAH phenanthrene, fluorene, and, reported here for the first time, fluoranthene.

The Materials and Methods

88

Chemicals. Nutrient broth medium and bacto-agar (Difco) were purchased from Nordwald KG (Hamburg, FRO), PAH from Aldrich-Chemie (Steinheim, FRG) and solvents from Riedel de Haen (Hannover, FRG). All other chemicals and reagents were commercial products of the highest purity available.

Enrichment, isolation and identification o f microor­ ganisms. The mineral salt medium (MSM) used as basal medium for enrichment and isolation contained (per litre

deionized water) lg K2HPO4, lg NH4NO3,	0.2 g
MgS04-7H20 , O.lg CaCl2-2H20 , 0.1 g NaCl, 0 .0 1	g FeCl3

•6H20 and 1 ml trace element solution (Pfennig and Lippert 1966) and was adjusted to pH 7.2 by adding 1 MHC1.

Bacterial cultures with PAH degradation potential were enriched in pneumatically operated percolators with an ex­ ternal loop as described by Codner (1969). The reactor was run with MSM for 1 month at room temperature containing 50% w/w) samples of contaminated soils and 50% (w/w) Raschig rings. In order to adapt soil microorganisms to de­ grade PAH, phenanthrene, fluorene and fluoranthene were supplemented (0.1% w/w each). The circulating fluid was used as inoculum or enrichment cultures which were incu­ bated in tightly closed 100 -ml erlenmeyer flasks containing 10 ml selective media (1 mg PАН/ml medium respec­ tively).

Unless otherwise mentioned, all media used for experi­ ments contained the respective PAH as sole carbon source and were incubated on a rotary shaker (1 0 0 rpm/30 °C). Flasks containing MSM without a carbon source served as controls incubated simultaneously.

Growth of the cultures was monitored either spectrophotometrically (Photometer type 1101 M, Eppendorf, Hamburg, FRG) at 578 nm or by the determination of pro­ tein (Lowry et al. 1951).

89