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The growth kinetics and the structure of oxides, as well as the macrostresses and density of the fixed positive charge are studied in SiO2 films up to 50 nm thick, obtained by thermal oxidation in dry oxygen at T = 1373 K. At a certain stage of oxidation, growth kinetics anomalies and changes in macrostresses and the density of the fixed positive charge due to structural transformations in the oxide (spontaneous amorphization effect) are observed. The obtained results are explained on the basis of the physical double-zone model of the silicon heterogeneous oxidation reaction. [Russian Text Ignored].

The ways in which electronically excited molecular systems are deactivated are examined, a theory of the non-adiabatic and predissociation mechanisms for the decomposition of molecular systems with elimination of a hydrogen atom is described, and the isotope effect in this reaction is discussed and compared with experimental data. The photochemical stability of molecules of different classes, radical-cations, and radicals is explained on the basis of the theoretical results. The evolution of atomic hydrogen (formation of radicals) in low-temperature radiation-chemical experiments is associated with the position of the lowest triplets state of the molecules, their ionisation potentials, the polarity of the medium, and the energies of the C–H bonds in the radical-cations. The bibliography includes 95 references.

Existence theorems on optimal controls for systems with distributed parameters and with trajectories given by a general operator of the form up(t, w, v) are proved. A set of quasiregular functionals is chosen as a criterion of optimality of the process. Such a choice essentially exhausts the cases which are practically interesting in applications.

The scheme used at the Ust'-Khantaisk hydroelectric station for passing construction discharges markedly reduced the amount of earth-rock work in the preparation of the structures for passage of floods, reduced the volume of work on the embankments by 200,000 m3, on underground rock excavation by 135,000 m3, and on placement of underground concrete by 10,000 m3, and according to the calculations of the Siberian Branch of Gidroproekt, affected an economy of about 5 million rubles.

Experience in construction and in the first period of operation of the Ust’-Khantaisk HES merits the following conclusions: 1. Passing discharges over a partially erected rock-fill dam in the construction of a hydrocenter is technically feasible, dependable, and economically advisable for rivers with a flow regime typical of northern regions. 2. An underground HES building is most suitable for northern hydroelectric stations. 3. Existing instructions on antiseepage arrangements in dams are very laborious. It is therefore necessary to seek new technical solutions. Use of polymer materials deserves special attention, but their durability must be thoroughly investigated. 4. The lack of an excavator with a 3–5-m3 bucket for work under northern conditions and of large capacity cranes must be pointed out. 5. The labor-consuming nature and difficulty of building dams on a soft foundation composed of lacustrine-swampy and lacustrine-glacial deposits in boggy, and permanently frozen states call for new technical solutions and for the design of special earth-moving equipment suitable for work under such conditions.

In this work we establish necessary and sufficient optimality conditions, and a theorem on the uniqueness of optimizing functions for control systems of general type.

1. The experience of constructin the Khantaika hydroelectric scheme confirmed the practical possibility and economic expediency of using the pioneer method of damming river channels under conditions of the Far North at heads of 5–7 m at the upstream rock embankment. 2. The practical possibility of damming northern rivers during the fall-winter period at river discharges to 500 m3/sec and of achieving a dumping rate from one bank of 400 m3/h with a limited number of vehicles was proved. The rate can be doubled if vehicles are available for dumping from both banks. 3. The pioneer method of damming rivers produces backwater in the upper pool and thus permits regulating the velocity of approach of the stream in order to prevent the entrance of slush and ice into the breach. This method eliminates the need to construct labor-consuming and expensive booms to combat ice. 4. At water velocities in the breach of 6–8 m/sec the use of oversize rocks weighing less than 15–20 tons is ineffective. Rocks of lesser weight should be cabled together into strings of 3–10 each. The volume of oversize rock should be at least 20% of the volume of fill. 5. The construction of approach roads to the site of damming under conditions of narrow canyons with a precipitous bank is accompanied by collapse of a large quantity of oversize rock into the river channel where the embankment abuts the river bank. This can create the danger of concentrated seepage through the retaining cofferdam of the foundation excavation for the plant. Therefore, effective measures should be worked out in the plans to combat seepage at the abutments of the cofferdam.

A new procedure is proposed for solving optimal problems. Necessary optimality criteria are obtained for a nonlinear time-optimal problem in the presence of several control parameters of different functional structure.

The necessary condition for optimality of control of a plant which can be described by a weakly nonlinear system of hyperbolic equations with constraints of the inequality type on the phase coordinates of the system at a stipulated finite time are derived.

In this article we prove an energy inequality for the third boundary value problem (the parabolic case) and certain completeness and closure properties of the system of eigenfunctions.

The gear-type vacuum press of the design developed, in which the feeder and the pressing device are made in the form of gears in contact engagement, is suitable for operation with mixtures of reduced moisture content and for production of thin walled parts of complex profile.

Existing calibration systems (float type, photoelectric with direct readout, etc.) for certifying gauges for warm liquids cannot be used in certifying cryogenic gauges on account of the specific features of cryogenic media: low boiling points (from 4.2 to 90~ and instability in the pressure, temperature, dielectric constant, etc. Therefore, the best method is to use semiconductor transducers in the calibration system. Semiconductor resistance thermometers are suitable for the purpose [I, 2]. In particular, one can use any semiconductor component with a nominal crystal diameter of 1.0-2.0 mm and a protective coating thickness not more than 0.05-0.1 mm in liquid nitrogen. These transducers have direct heating, and the output signal is displayed via a threshold relay. The direct heating of the sensitive element and the choice of relay threshold determine the mode of operation, which is based on the difference in heat transfer in liquid and vapor.

g plant control system which consists of several independent subsystems makes it possible to enhance the "viability" of the system because failure of one subsystem will not lead to failure of the whole system. The functions of each control subsystem are distributed between the local regulators, logical programming devices, and microcomputers. Further, the distribution of the control system function is so accomplished that the basic functions pertaining to the normal plant operation can be achieved with the aid of local automatic devices with a high reliability and the regime optimization function can be executed on a microcomputer. The control system being developed is meant for performing the following computer-aided information processing and control functions: monitoring of the current values of the technological parameters; operative information display and automatic accounting during the technological process; remote control of units and accessories; automatic control of the most important technological parameters; execution of program and logical operations; optimum control of the technological regime. The major economy due to the use of this system will accrue from the solution of the problem of regulation of the AFP productivity in the case of uneven consumption of oxygen by varying the productivity of the compressor, It must be noted that the consumption regime can be expressed in the form of dependences of the flow rates and concentrations of the air-fractionatio n products on the time in a set time range. To attain a new productivity, the plant control system alters the flow rates of the main technological streams by acting on the set-point devices of the regulators, whereupon the uncontrollable flow rate of the still liquid changes through regulation of the level in the

My breeding experiments on Locusta migratoria, L., in 1913−14 enabled me to establish that the progeny of this species sometimes belongs to the form which was previously regarded as a distinct species, L. danica, L., and in the same way, the latter insect may give rise to progeny that is typical of L. migratoria. These results have been used by B. P. Uvarov in developing his theory that the periodicity of locusts is due to a kind of irregular alternation of two phases, swarming (ph. migratoria) and solitary (ph. danica), respectively. I shall not dwell here on that theory or on the differences between the two phases, referring those interested in the subject to Uvarov's paper, but will describe further breeding experiments conducted during the year 1923 with a view to obtaining an idea as to what may be the factors that cause the variation in the species.

Separate and combined effect of TChAA and DMS was studied as applied to Arabidopsis of Estland race. When the Arabidopsis seeds were treated with TChAA in M1 separately, stimulation was observed as to certain features. A combined treatment with TChAA + DMS reduces significantly the yield of chlorophyll mutations both as compared to variants of separate treatment and to those of control. On the basis of the data obtained an important role of histones in mutation process is suggested.

The investigation of biological activity of two coordination platinum (II) compounds covalently linked with Fab-fragments of nonspecific immunoglobulin donors on mononuclears of peripheral man blood in vitro and blood elements of mice BALB/c has been done in this paper. There have been stated the decrease of cytotoxic activity of platinum reagents after complexing and modulating influence of platinum-globulin complexes on immunocompetent cells. The prospects of increasing biological activity of immunological preparations on the basis of directed modification by platinum reagents has been also discussed.

Experiments on 110 white noninbred tumor-free rats were made to explore the myelotoxic action of a new antineoplastic drug spirobramine. A single (200 mg/kg) intravenous injection and a course of drug treatment (40 mg/kg 5 times every other day) produced monotypic changes in the peripheral blood and bone marrow hemopoiesis, primarily marked by inhibition of erythroid, eosinophilic and thrombocytic myeloid fibers followed by the development of moderate anemia, thrombocytopenia and aneosinophilia in the peripheral blood. A single injection of spirabramine in an MTD produced more pronounced changes in the blood than injection of the drug in divided doses.

In tests conducted on 220 rats with transplantable sarcoma M-1 and intact animals acute toxicity, antineoplastic effect and the action on the blood system of tomizine, a new neoplastic drug of the group of the folic acid antagonists, were studied. Investigation involved a single intraperitoneal injection of the drug in DL50/30 and MTD. The compound is shown to exert an inhibiting action on the development of sarcoma M-1 and lengthens the survival of the tumour-stricken animals, without producing any pronounced myelotoxic effect. The disclosed shifts on the level of the periphedal blood and marrow were short-lived and concerned mainly the erythroid germ cells.

The paper is concerned with the results of experimental studies on the equivalent doses of irradiation of 11 organs and tissues by which one can calculate effective equivalent doses per study. Calculation were done on an anthropomorphous phantom of "conventional" man with the help of a thermoluminescent dosimetric system based on lithium fluoride. Equivalent doses were evaluated by the mean calculated value. The tabulated results make it possible to determine equivalent doses.

In poikilotherm animals--the frog Rana ridibunda, lizards Lacerta strigata, Eremias arguta, snake Natrix tesselata--high glycogen and glucose concentrations have been found not only in the liver, but also in muscles and especially in the brain. The content of glycogen in the brain of the reptiles investigated is 63.5--4.2 times higher, whereas that of glucose--6.9--39.5 times higher than in the brain of rats. The level of free fatty acids in the blood of frogs and snakes studied is the same as in rats, being 3.8 times higher in the blood of the lizards.

For a more precise diagnosis of the level of nucleus pulposus herniation in lumbar osteochondrosis, a table has been compiled taking into account 35 signs of the disease. It is based on numerical evaluation of individual symptoms of the disease depending on their topico-diagnostic importance. The table was checked on 108 patients with discogenic lumbosacral radiculitis treated at the neurosurgical department of the clinic in whom posterolateral or paramedial herniation of the nucleus pulposus at the level of L4 or L5 was discovered during the operation. The table diagnosis proved to be correct in 91% of patients, while the preoperative clinical diagnosis--only in 82% of patients. All this provides the grounds for the use of this table in precise diagnosis of the level of nucleus pulposus herniation in discogenic lumbosacral radiculitis.