Effect of the density of the electronic states at the valence orbital of the bridge redox molecule on the dependence of the tunnel current on the overvoltage in the case of fully adiabatic electron transition

Effect of the density of the electronic states at the valence orbital of the bridge redox molecule on the dependence of the tunnel current on the overvoltage and on the width at half maximum of the current-overvoltage curve is studied. A number of the approximate expressions for the density of states, the tunnel current and the width are obtained in the fully adiabatic limit for different particular cases. It is shown that at small values of the coupling of the electronic levels of the electrodes with the valence orbital of the redox molecule and the small values of the bias voltage two regions of the reorganization Gibbs energy exist with different dependence of the width on the reorganization Gibbs energy. The results of calculations of the density of states, the tunnel current and the width are presented and used for the interpretation of the experimental data [N.G. Tao, Phys. Rev. Lett. 76 (1996) 4066, I. Visoly-Fisher, K. Daie, Y. Terazono, C. Herrero, F. Fungo, L. Otero, E. Durantini, J.J. Silber, L. Sereno, D. Gust, T.A. Moore, A.L. Moore, S.M. Lindsay, PNAS 103 (2006) 8686].     

Preparation of an acrylics‐grafted polyester and its aqueous dispersion—mechanical properties of acrylics‐grafted polyesters

Mechanical properties of grafted polyesters were discussed. In the case of grafting of acrylics of more than 25% in the grafting product, mechanical properties of the grafting products decreased greatly compared with the raw polyester. The influence of the molecular structure of the grafted polyester was not observed. The effect of composition of the grafted polymers was discussed. Mechanical properties varied with the composition of the side chain. In the case of grafting onto aromatic polyesters, grafting of an aromatic unsaturated monomer improved the mechanical properties of the grafted polymer. On the other hand, in the case of grafting onto an aliphatic polyester, grafting of an aliphatic unsaturated monomer improved mechanical properties of the grafting polymer. We found that the grafting of the polymer having a high compatibility with the polyester improved the mechanical properties of the grafting products, from the determination of the compatibility of each polymer and the mechanical properties of the grafting products. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1149–1157, 2000     

Reflection of a shock wave from a rigid wall in a mixture of a liquid metal and solid particles

The problem of reflection of shock waves and expansion waves from a rigid wall in a mixture of liquid iron and small molybdenum crystals is considered. The study is performed within the framework of equilibrium and nonequilibrium approximations of mechanics of heterogeneous media with different pressures of the components. The mathematical model is verified by fitting the dependence of the equilibrium-frozen velocity of sound on the initial pressure in the mixture with available experimental data. In the equilibrium approach, the dependence of the type of the reflected wave on the type of the incident wave is determined. Direct numerical calculations within the framework of the nonequilibrium model of mechanics of heterogeneous media confirmed the validity of the reflection chart obtained. The possibility of significant compacting of molybdenum particles in reflected waves is revealed. Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 4, pp. 97–107, July–August, 2000. This work was performed within the framework of the Integration Project No. 97-24 of the Siberian Division of the Russian Academy of Sciences.     

Stabilisierung von Polypropylen durch Mischungen substituierter Phenole und Di-n-alkylsulfide

This paper is dealing with the synergistic effect of some phenolic antioxidants, e.g. 4,4′-butylidene-bis(3-methyl-6-tert.-butylphenol), 2,2′methylidene-bis(4-methyl-6-tert.-butylphenol) and 4,4′-thio-bis(3-methyl-6-tert.-butylphenol) with di-n-alkylsulfides of various chain lengths and of sulphoxides and sulphones of the latter on the induction period of oxidation of polypropylene. The influence of the type of the phenolic antioxidants in the mixtures of stabilizers, the influence of the length of the alkyl chain of the sulphide component and the influence of the temperature was studied. Because an interaction between the mentioned substances and the formed peroxides during the inhibition of polypropylene in the presence of sulphides and their derivates was considered, the effect of sulphides, sulphoxides and sulphones on the decomposition of tert.-butyl hydroperoxides was studied.     

聚乙烯醇改性及吹膜技术研究

研究了聚乙烯醇（PVA）改性及吹膜技术。经改性剂改性前后的IR分析结果表明，改性剂与PVA分子间发生了强烈的相互作用，并形成了较强的分子复合键。改性PVA塑化温度的研究表明，醇解度为88％的PVA，随相对分子质量的增加塑化温度升高。醇解度升高时，PVA塑化性能下降；改性剂用量增加，塑化温度下降。吹膜工艺研究表明，成膜助剂的加入能明显改善改性PVA的加工流动性，PVA膜对冷却效果要求较高，吹膜后的热定型处理能降低其吸湿性，延长水溶时间。     

Refractory compounds of basic composition for the monolithin lining of steel-teeming ladles

Conclusions Questions of the method of production of basic ramming compounds at Panteleimonovka Refractory Plant and their use in the monolithic lining of the walls of 160-ton steel-teeming ladles of the No. 2 Converter Shop of Kirvoi Rog Steel Combine are considered.An analysis of the wear of the lining during service showed that it occurs as the result of spalling of the sintered zone and salamandering of the lining. The use of a movable thermally insulated lid made it possible to hold the temperature of the ladle lining within limits of 730–1120°C between heats and to obtain a basic rammed lining life of 21–39 heats as opposed to an average life for the shop of 14.8 heats.A reserve for increasing the ladle basic lining life is optimization of the thermal conditions of its service, including high-temperature heating of the lining before pouring of the metal, the use of thermally insulated lids with the minimum consumption of time for placing of them, an increase in the life of the well refractory to the life of the walls and bottom, and elimination of cooling of the lining between heats.A Discussion: Problems of the Production and Use of Refractories for the Lining of Steel-Teeming Ladles. [For the start of the discussion see No. 8 (1988) and for the continuation Nos. 9–12 (1988) and Nos. 1–3, 5, and 7 (1989).]Deceased.I. I. Glaka, N. F. Drobot, N. V. Kurmaz, B. P. Zinchenko, S. A. Poznyak, I. M. Ryaboshapkin, V. V. Slushko, A. A. Chulkov, Yu. Bormatov, S. I. Vanchyuk, V. I. Dobrovol'skii, B. G. Zhuravel', N. I. Kiyan, L. I. Nekrasov, N. M. Sokolov, P. V. Khomenko, G. A. Nikitenko, S. Dorgobuzov, P. I. Valiev, N. N. Gorbatko, V. I. Kovalenko, and M. I. Lyakhov of Krivoi Rog Steel participated in the preparation and tests of the basic monolithic linings.Translated from Ogneupory, No. 8, pp. 1–4, August, 1989.     

Die differentielle Doppelschichtkapazität an der Phasengrenze Quecksilberanorganischer Elektrolyt—II. Das Kapazitätsminimum

In the negative range of charge, the differential double-layer capacitance at the interface of mercury and an inorganic electrolyte solution shows a characteristic minimum. This minimum is independent of the nature of the ion, of the concentration of electrolyte and of the temperature. However, the solvent strongly influences the capacitance of the minimum. The metal charge at which the minimum occurs is uninfluenced only by the temperature. Changes of the concentration of the electrolyte as well as of the nature of the anion are able to cause a shift of the minimum.     

硼酸钙对铜渣中夹杂铜沉降效果的影响

考察了添加剂CaB2O3对转炉铜渣中夹杂铜沉降效果的影响，并结合铜渣的粘度测试及红外光谱表征，研究其影响机理，采用FactSage软件计算了添加剂对铜渣液相线温度的影响。结果表明，随添加剂含量增大，铜渣中夹杂铜的沉降效果逐渐增强，添加剂含量由0增至6wt%时，底部渣含铜量由4.10wt%增至6.85wt%，这是由于添加剂可有效降低铜渣粘度。随添加剂含量增大，渣粘度降低，但降低效果随温度增大而趋于平缓。随添加剂含量增大，铜渣的硅酸盐结构趋于简化，添加剂通过破坏铜渣复杂的硅酸盐结构降低铜渣粘度。铜渣的液相线温度随添加剂含量增大而减小，添加剂通过减少渣中固体颗粒的方式降低铜渣粘度。     

氮气幕对瓦斯爆炸进行阻爆实验

为阻断瓦斯爆炸在管道方向上的传播，保护管道后方区域，本文采用氮气幕来进行阻爆，所设计的实验装置在爆炸发生后能自动喷出氮气。主要研究了氮气的喷气压力和喷气时刻对阻爆功能的影响。结果表明，在喷气压力为0.1MPa时，氮气幕仅起到抑制作用，爆炸火焰能穿过整个实验管道。在喷气压力为0.2MPa时，仅部分实验能够阻爆，氮气幕产生不稳定的阻爆效果。在喷气压力为0.3MPa时，阻爆位置均稳定在左喷头和右喷头之间区域，氮气幕产生稳定地阻爆效果。喷气压力超过0.4MPa后，阻爆位置稳定在右喷头附近。在较低氮气压力0.2MPa下，喷气时刻对阻爆效果产生显著影响。随着喷气时刻延迟，氮气喷出量减小，氮气幕由不稳定阻爆变为不阻爆。喷气时刻延迟到198ms后，氮气幕便丧失阻爆功能。在喷气压力超过0.3MPa后，氮气幕阻爆效果便不受喷气时刻的影响，喷气压力对能否阻爆起决定作用。     

Fractal structure and features of energy-release (combustion) processes in heterogeneous condensed systems

In this work, the theory of fractals has been used to describe the structure of heterogeneous condensed systems (HCS). Features of energy-release processes with variation of the initial structure parameters have been investigated. The microstructure of HCS and the dynamics of its change have been studied as functions of the proportion and properties of their components. It is shown that particles of the components form fractal structures, which are characterized by fractional dimensions. The obtained images of the microstructure reflect the presence of the geometric phase transition “fractal cluster-percolation cluster.” Regularities of reaction-front propagation are determined. It is found that the concentration limits of energy release and combustion are associated with the evolution of fractal structures and the formation (disruption) of a continuous reaction surface. The electrical conductivity of the starting compositions is measured as an indicator of the formation of fractal structures of one or another configuration. Electrical and thermal-physics properties of the samples and energy-release (combustion) parameters are analyzed. The systems exhibit similar behavior in different processes. Near the critical point, the dependence of the parameters studied on concentration has an exponential character. The exponent is close to that determined in percolation theory. A computational algorithm for the contact surface of the components is developed and implemented. The computation results allow one to distinguish the “base block” that influences the combustion rate and to determine the critical concentrations of the components. The study of HCS in the context of the new direction in the geometry of disordered systems—the theory of fractals—is promising for generalization of available experimental data and for predicting the parameters of energy release in HCS with variation in the structural parameters. Institute of Chemical Physics, Russian Academy of Sciences, Moscow 117977. Translated from Fizika Goreniya i Vzryva, Vol. 33, No. 5, pp. 3–19, September–October, 1997.     

The performance of the refractories in the stack of a 2700-m3 blast furnace

Conclusions The refractory lining of the cooled part of the stack eroded before the end of the campaign and the blast furnace was operated for 18 months without this masonry.In the furnace the refractory impregnated with the dustlike and gaseous products of the melting materials, viz., the ferrous compounds of the ore in the charge, oxide vapors of the alkali metals, and the components of the slag melt. The chemical conversions in the refractory result in the erosion of the lining of the stack. The refractory lining of the noncooled part of the stack remains in a satisfactory condition and may serve for 10 years or more without major patching.Hydrogen and soot carbon are not primary causes of the failure of the stack lining, but it would be difficult at this stage to give an unequivocal answer to the question of their contribution to the process of erosion.It was established that sphalerite deposits are confined to the heat cracks in the refractory and the joints in the masonry of the refractory lining of the shaft.Translated from Ogneupory, No. 4, pp. 18–26, April, 1977.     

含缩水甘油基／氨基丙烯酸酯共聚物乳液的聚合稳定性

研究了乳胶粒组成对含有缩水甘油基,羧基和胺基的丙烯酸酯多层核壳型乳液聚合稳定性的影响规律,探讨了聚合过程的凝聚机理。研究表明：官能团间的交联凝聚作用和水溶性聚合物的架桥凝聚作用是本体系凝聚物形成的主要原因。     

Calculation of the gasification of cokes of high-ash coals on the basis of the model of randomly porous media

A mathematical model is constructed to describe the dynamics of the pore structure of cokes of high-ash coals with allowance for the fact that the different parts of the internal volume of the structure are not equally accessible to the gaseous reactant. The model accounts for the increase in the area of the pore structure due to the removal of organic material, coalescence of pores, and opening of the interior volumes of the sample in the course of conversion. In the examination of heat- and mass-transfer processes inside the particles, attention is given to the thermal effect of the reaction along with diffusion resistance in the mineral component and the layer of reaction products — which decreases the cross section of the transport pores. The results of the calculations are compared with experimental data on the gasification of culm in gaseous carbon dioxide.Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 2, pp. 58–65, March–April, 1992.     

Preparation of an acrylic‐grafted polyester and its aqueous dispersion—Effect of the molecular structures of the grafted polyesters on viscosity and rheology of dispersion

An investigation was undertaken to develop a new class of water‐borne polyesters that have various viscosity and various rheological profiles. We discussed the effect of the grafting condition on the molecular weights of the acrylic segments in the acrylic‐grafted polyester. The molecular weights of the acrylic segments could be changed by an initiator concentration, a chain transfer agent concentration, and a monomer concentration. We discussed the viscosity and the rheology of the dispersions obtained from the above‐grafted polyesters. The viscosity of the dispersion decreased as the molecular weights of the acrylic segments decreased. It was considered that the interaction between the particles of the dispersions decreased with a decrease in the thickness of the shell layer. The viscosity of the dispersions also decreased as the solubility of the acrylic segments in water decreased. It was considered that the interaction between the particle of dispersion decreased with the shrinkage of the shell layer. The rheological profile of dispersion was changed not by the molecular weights but the composition of the acrylic segments. The dispersions having various rheological profiles could be obtained by the control of the molecular weights or the composition of the acrylic segments in the grafted polyesters. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 350–356, 2000     

Autoregression method for determining the decrement and frequency of the natural oscillations of a gas in a combustion chamber

Conclusions A new method for determining the decrement and frequency of the natural oscillations of the gas from the intrachamber noise for stable combustion regimes has been developed. The accuracy of estimates of the decrement and frequency of oscillations obtained by the given method has been analyzed, and rules for processing of realizations of random oscillations of the gas have been determined which provide the required accuracy of the estimates of the decrement in the range 0.01–0.4. The proposed approach for the construction of an algorithm for the processing of experimental data reduces the problem to a linear one and allows the application of mini- and micro-computers to its solution. The method possesses low sensitivity to the presence of additive noise in the recorded signal and provides the required accuracy for the determination of small values of the decrement. For the choice of a filter which ensures a signal/noise ratio of 16 or greater, application of the method is not required if simulators are employed in the calibration of the analytic procedure. The proposed method can be implemented in all branches of technology where the mechanism of generation of processes to be analyzed can be represented as the response of a linear, oscillatory system to a wide-band random input. Moscow. Translated from Fizika Gorenia i Vzryva, Vol. 23, No. 6, pp. 33–40, November–December, 1987.     

含气泡油滴撞击矩形沟槽壁面的数值分析

采用耦合水平集-体积分数（CLSVOF）方法对含气泡油滴撞击矩形沟槽壁面现象进行数值模拟研究,考察了油滴撞击壁面后的形态演化过程,分析了中心射流形成机理和气体夹带的分布规律,并探究了沟槽宽度、沟槽深度和撞击位置对油滴铺展特性的影响。研究表明：含气泡油滴在矩形沟槽壁面铺展时会形成中心射流,沟槽内部存在气体夹带现象。气泡底部的速度旋涡是形成中心射流的主要原因,沟槽内的气体夹带受油滴铺展速度影响呈现规律性分布。沟槽宽度对含气泡油滴在垂直沟槽方向和平行沟槽方向的铺展长度影响较大,但对铺展高度影响较小。当无量纲沟槽宽度为0.3时,油滴形成颈部射流并在运动后期使垂直沟槽方向的铺展长度迅速增加。此外,沟槽深度也对含气泡油滴在各方向的铺展有重要影响,沟槽深度越大,中心射流现象越难形成。撞击位置变化不改变油滴在沟槽壁面上的运动演化过程,但对沟槽内部的气体夹带规律有一定影响。     

Numerical investigation of the influence of material properties and adhesive layer thickness on the heating efficiency of microwave curing of an adhesive‐bonded joint

In the process of microwave curing of an adhesive‐bonded joint, both the adhesive layer and the adherends affected the heating efficiency of the joint. As an extension of previous studies, the influences of changing the properties of the components of the joint on the heating efficiency were predicted by simulations that were based on the numerical model developed previously. The influence of adhesive thickness was also studied. The properties that directly affected power dissipation and heat loss of the adhesive layer were found to be important to the heating efficiency of the process. The heating rate was also sensitive to the thickness of the adhesive layer. Polym. Eng. Sci. 44:1414–1418, 2004. © 2004 Society of Plastics Engineers.     

Phase composition of the products of encrustation of the channels of magnetodynamic feeders for aluminum alloys

Conclusions The investigations made it possible to establish the composition of the crust and the influence on its formation of certain service factors. In operation of MDN-6A feeders encrustation of the channels has a local character. The crust is formed in one of the side vertical portions of the channel. Failure of the crucible lining, contamination of the metal with coarse nonmetallic particles, and the occurrence of local overheating in the channel influence the operating life of the channel and the feeder in general. The rate of crust formation is determined by the quality of the lining fluorophlogopite material. The presence of cracks, shrinkage porosity, and an increased quantity of free glassy substance causes acceleration of failure of the channel lining.Translated from Ogneupory, No. 3, pp. 49–52, March, 1988.     

Acoustophoretic studies of aqueous suspensions of alumina and 8 mol% yttria stabilised zirconia powders

The iso electric points (IEPS) of four alumina powders and three 8 mol% yttria stabilised zirconia powders were investigated using acoustophoresis to measure the zeta potential as a function of pH. All the powders were characterised by X-ray fluorescence spectroscopy for elemental composition and BET nitrogen adsorption for surface area. Initial experiments revealed that the IEPS of the alumina powders were independent of the volume fraction of the alumina suspensions. Further experiments investigated the effect of adjusting the pH with different bases, i.e. NaOH, KOH, and NH₄OH, on the IEPS of the alumina powders. The IEP of an individual powder was independent of the base used, however, the degree of hysteresis varied depending on the polarisability of the cation. The smallest degree of hysteresis was recorded with additions of NaOH. The differences in IEP between the alumina powders were attributed to the different surface chemistries of the powders. For the zirconia powders the IEP of each suspension was identified using HCl and NaOH to adjust the pH. Again the differences in the IEP were attributed to different surface chemistries of the powders. Two of the powders demonstrated an IEP of approximately 6.5; however the Tosoh powder suspension demonstrated considerable hysteresis and an IEP of 9.3. This was due to its natural pH being an approximate pH unit lower than the other two powders. At this lower natural pH, yttria dissolved out of the Tosoh powder, generating yttrium ions in solution. These precipitated onto the powder surface and altered the surface chemistry with time; i.e increased the zeta potential. Atomic absorption experiments on the supernatant confirmed the dissolution of the yttria from the Tosoh powder.     

Homogenizing role of hydrogen in the synthesis of multicomponent Carbohydrides and Nitridohydrides of transition metals in the combustion mode

This work presents the results of study of combustion with carbon of transition metals of IV, V and VI groups of the periodic system in atmospheres of argon, hydrogen, nitrogen and nitrogen-hydrogen mixture. The significance of hydrogen in the formation of single-phase products in the self-propagating high-temperature synthesis (SHS) mode was underlined. The combustion of carbon containing systems in argon resulted in the synthesis of two-phase carbides with FCC lattice. In contrary, the combustion of the same systems in hydrogen atmosphere leaded to the synthesis of single-phase carbo-hydrides. The products of combustion of transition metals in nitrogen atmosphere were the multiphase nitrogen-containing compounds. Their following re-ignition in hydrogen leaded to the synthesis of single-phase nitrido-hydrides. It was demonstrated that in all the studied systems, the combustion in hydrogen atmosphere leaded to the homogenized final synthesis products. The results of these processes were the formation of single-phase carbo- and nitrido-hydrides based on the metals of IV, V and VI groups. The presence of hydrogen in the crystal lattice of synthesized refractory carbides and nitrides facilitated easy dispersion of the compound to submicron sizes. After removal of hydrogen, the single phase structure was not violated. The described results may be of commercial value in the industry of refractory materials.