预制体结构对炭／炭复合材料力学性能影响

四种用于制备炭／炭（C／C）复合材料的预制体，即1K发布叠层坯体（1#坯体），3K发布叠层坯体（4#坯体），发市 炭纸叠层坯体（2#坯体），特殊炭毡 发布叠层坯体（3#坯本），并探索了预制体结构对C／C复合材料力学性能影响．研究表明：用1#坯体制备的C／C复合材料弯曲强度最高，2#坏体制备的材料弯曲强度最低，随著炭纤维（CF）体积含量的增加，用四种坯体制备的材料弯曲强度增大。确定了弯曲强度的优化配方．     

纤维体积含量对炭／炭复合材料性能的影响

通过对不同纤维体积含量的炭／炭复合材料进行力学性能、导热、导电性能试验,分析了纤维体积含量对炭／炭复合材料性能的影响。初始坯体的纤维体积含量对炭／炭复合材料力学性能影响较大,导热、导电性能则与材料内部结构关联较大而与纤维体积含量的关系不大。预制坯体的纤维体积含量选为25％至30％为最好。     

金属/Al2O3基纳米复合材料研究最新进展

金属／Al2O3纳米复合材料在保持原有金属的功能特性时，还可以获得 很好的力学性能，是有良好发展前景的一种纳米复合材料。本文回顾了近年来金属／Al2O3基纳米复合材料在制备工艺，微观结构和力学性能，增韧强化机理方面的最新进展，并指出了今后的研究方向。     

ZrO2和Ni复合掺杂对Al2O3陶瓷结构及性能的影响

利用非均相沉淀包覆-热还原工艺制备粒径分布均匀、表面光滑的球形Al2O3/ZrO2/Ni,Al2O3/Ni,Al2O3/ZrO2复合结构粉体,再经真空热压烧结得到相应的复合陶瓷.通过X射线衍射和扫描电镜对前躯体、热还原粉体及烧结陶瓷的成分及结构进行了表征,并对陶瓷的力学性能、介电常数进行了检测和分析.实验结果表明:金属Ni的引入抑制了Al2O3的致密化,细化了晶粒,强化了氧化铝晶界,使氧化铝发生穿晶断裂而起到增韧效果;ZrO2对Al2O3陶瓷致密化及细化晶粒作用不明显,但通过相变增韧或形成弱界面起到了较好的增韧作用;Al2O3/ZrO2/Ni复合材料的断裂韧性增加值并未高于Al2O3/Ni和Al2O3/ZrO2 2种复合材料断裂韧性增加值之和,但增强了空间电荷的极化,使复合材料具有较高的介电常数.     

Fe3Al/Al2O3复合材料的凝胶注模成型工艺研究

机械合金化法制备Fe3Al粉,用凝胶注模成型的方法制备Fe3Al/Al2O3复合材料.结果表明,用凝胶注模成型工艺制备出了Fe3Al/Al2O3复合材料,分散剂MN可以显著提高浆料的固相含量,固相含量对浆料流变性有重要影响,10% Fe3Al/Al2O3坯体的微观结构最均匀.     

激光功率对聚己内酯基人工骨支架的影响

采用羟基磷灰石(HAP)和聚己内酯(PCL)作为原料,将HAP/PCL按1∶9的质量比制备HAP/PCL复合材料,打印成型后,测量其力学性能并进行分析研究。结果表明,所制备复合材料可用于选择性激光烧结技术,其烧结制件具有生物相容性并有较高强度。     

PPC/纳米羟基磷灰石复合材料的制备及其性能研究

采用共混的方法制备了聚碳酸亚丙酯(PPC)/羟基磷灰石(HAP)复合材料,研究了HAP用量对于PPC/HAP复合材料断面形貌、力学性能、接触角和流变性能的影响。断面形貌分析结果表明,纯PPC材料属于韧性断裂,随着HAP用量的增加,PPC/HAP复合材料逐渐转变为脆性断裂;HAP在PPC基体中能够均匀分散,二者具有良好的界面相容性。力学性能测试结果表明,PPC/HAP复合材料的断裂强度和冲击强度随着HAP用量的增加逐渐提高,而断裂伸长率随着HAP用量的增加逐渐降低。PPC/HAP复合材料具有良好的亲水性,且亲水性与HAP的用量成正比。流变测试结果表明,PPC/HAP复合材料的表观黏度具有温度和剪切速率敏感性,且复合材料的表观黏度随着HAP用量的增加先提高后降低。     

纳米Al2O3/环氧树脂复合材料的制备及性能

在原位法制备纳米复合材料时，要使纳米粒子在树脂中分散均匀，必须首先获得稳定的单体悬浮体系。基于这一原理，本文通过对纳米Al2O3表面改性即选择合适的分散剂，获得稳定的纳米Al2O3/丙酮悬浮液，然后将环氧树脂溶解于其中，制得纳米Al2O3／环氧树脂复合材料。运用透射电子显微镜，观察了纳米Al2O3在环氧基体中的分散情况。分析并讨论了纳米Al2O3含量对该复合材料力学性能的影响。结果表明：利用稳定的悬浮体系能制得分散较为均匀的纳米复合材料，在纳米Al2O3含量为5％的情况下，纳米复合材料的力学性能达到最优。     

Al2O3/Al复合材料的制备及性能研究

本文采用液相法和热压烧结制备出Al203／Al复合材料,并利用DSC／TG、SEM、显维硬度计及万能试验机测试研究了复合材料的热学性能、微观结构及力学性能。结果表明,引入Al后复合陶瓷的断裂韧性有显著提高。     

选区激光烧结制备PS/Al2O3纳米复合材料的研究

试探性地利用选区激光烧结制备PS／Al2O3纳米复合材料，利用乳液聚合方法改性纳米Al2O3，并在相同工艺条件下对PS／Al2O3纳米复合材料成型粉末（NH1）与纯聚苯乙烯（PS）粉末选区激光烧结试样的力学性能进行了比较结果表明，NH1烧结试样（PS／Al2O3纳米复合材料）较纯PS的拉伸强度提高了2倍左右，最大值达到29．8MPa；缺口冲击强度提高了20％～50％，最大值达到10．5kJ／m^2；洛氏硬度仅增加约5％；并利用场发射扫描电子显微镜对试样的冲击断面进行了微观结构分析．发现纳米Al2O3经乳液聚合改性后在基体中分散良好，起到很好的增强增韧作用．     

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。     

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.     

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.     

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.