Measurement of the vertical aerosol distribution in the middle atmosphere by the twilight sounding method

Vertical variations of optical characteristics of atmospheric aerosol (air turbidities and logarithmic gradients of intensities) at altitudes between 20 and 150 km were obtained by twilight photometry carried out between 1942 and 1993 at the Abastumani Astrophysical Observatory in Georgia. The reported data include periods of increased volcanic and meteor activities. Also shown are air turbidity curves for different latitudes obtained in 1974 soon after the eruption of Fuego; these were derived from photographs of the earth's sunlit limb from the spacecraft Soyuz 16. A combined curve of vertical aerosol distribution typical of the middle atmosphere is presented.     

Thermal Explosions in the Early Evolution of the Earth

Exothermic regimes in the Earth's interior at an early stage of evolution are considered. Conditions are found that lead to selfaccelerating development of gravitational differentiation—separation of the heavier material forming the Earth's core from silicates in extended and heated local areas.     

造纸中段废水预处理工艺研究

根据北方造纸中段废水的特性,选择水解酸化法、生物/化学(BC)法、铁屑微电解法分别作为造纸中段废水的预处理工艺,同时分别与相同生物处理构筑物(复合生物反应器)组合,在相同的工艺参数条件下进行了对比试验.结果表明,BC法单独预处理对CODCr、BOD5、SS、色度的平均去除率分别为62.8%、43.45%、80.8%、80.8%,其处理效果均好于其他两种,同时BC法与复合生物反应器组合工艺出水结果也非常理想,因此,BC法为造纸中段废水的最佳预处理工艺.     

The role of gas atmosphere in the sieving process

We have investigated the effect of noble gas on sieving fine powders. Experiments show that the throughout is increased by approximately 35%. The results indicate that chemisorption is an important factor when sieving fine powders.     

Effect of Properties of the Source on the Action of Explosions in Air and Water

Results of an experimental study of parameters of the shock wave and explosion products in the near zone of explosions in air and water with a wide range of variation of explosion heat and charge density of high explosives are presented. It is shown that the influence of these characteristics on the action of explosions in the near zone can be characterized by one parameter: volume concentration of energy in the source. A change in this parameter involves a significant redistribution of energy between the explosion products and the shock wave, which can affect brisance and violate the energy similarity of explosions.     

Liminescence in water and glycerin in the field of spherically focused and plane shock-acoustic waves

The dynamics of luminescence generation and cavitation in the field of spherically focused and plane shock-acoustic waves in water, glycerin, and their mixtures is studied. It is shown that in the spherical focusing of shock-acoustic waves, the first pulse of luminescence correlates with cavitational rupture of the liquid. It is assumed that the registered luminescence is caused by electrokinetic processes upon formation and growth of cavitational bubbles. Translated fromFizika Goreniya i Vzryva, Vol. 35, No. 6, pp. 125–128, November–December 1999.     

FC-28型单段高中油型加氢裂化催化剂的工业放大

以改性Y型分子筛为主要酸性组分，钨镍为加氢组分，采用浸渍法制备了FC-28型单段高中油型加氢裂化催化剂。FC-28型单段高中油型加氢裂化催化剂工业放大结果表明，该催化剂制备工艺成熟可靠，重复性好，FC-28型放大催化剂的反应性能完全达到了实验室定型催化剂的水平。FC-28型单段高中油型加氢裂化催化剂工艺条件考察试验结果表明，该催化剂对工艺条件变化适应性强，中间馏分油产率高，活性适中，并具有较好稳定性。     

Multiple Tank Explosions in an Edible‐Oil Refinery Plant: A Case Study

Multiple explosions occurred when five workers were acting on a footbridge structure at the top of crude olive pomace oil tanks. Welding on the tank roofs was performed without previously cleaning the tanks stopping their operation. First, one of the several ～ 650‐m³ reservoirs exploded, provoking a pool fire that spread throughout the tank farm. Roughly 1 h later, two other reservoirs exploded causing the launching of missiles to a distance of 60–80 m and a huge fire that extended throughout the entire tank farm. Four workers were killed instantaneously. The explosion was caused by the unusually high content of hexane in the crude olive pomace oil and, hence, by the inefficiency of the desolventization process which creates a flammable and explosive oil from a combustible one.     

The role of ion—ion interactions in the electrical double layer: symmetrical electrolytes containing equal size ions

A simple model for the ion distribution at the metal—electrolyte interface is presented, based on charge redistribution in response to a change in potential across the interface. In this model, it is not necessary to subdivide the interface along the lines of the traditional approach to the double layer problem. The most important feature of our appraoch is an emphasis on ion—ion repulsion within a thin region of reduced (macroscopic) permittivity parallel to the metal surface.     

新型对称双偶氮苯化合物的合成及光学性能

以联苯二胺为原料,通过重氮化、偶联和Williamson醚合成反应,设计合成了一系列新型的对称性不同端基的双偶氮类化合物,考察了溶剂、不同取代基对偶氮化合物紫外吸收影响。以4,4’-二(4-辛氧基-苯偶氮基)-联苯(Azo3)为例,在365 nm紫外光照射下发生反-顺光异构化,光照10 min后达到光稳定态,具有良好的光致变色性。     

烧成气氛对陶瓷产品缺陷的影响及控制分析

以陶瓷烧制过程的物理变化和化学反应理论为指导，分析了烧成气氛对建筑陶瓷产品某些缺陷的影响，并结合理论与实际操作经验，探讨烧成过程中控制气氛制度要注意的问题。     

On the mixing properties of spherically symmetric helical coherent structures in turbulence

A paradigmatic family of flow fields for localized, spherically symmetrical flow with maximal helicity—a model for helical coherent structures that are localized—is introduced. The Lagrangian mixing of the lowest order member of the family that is truly 3-D due to spiral arms is analyzed with linear theory, demonstrating that trajectory growth rates for the short, convective time scale are exponential and bounded by the extremal eigenvalues of the Jacobian. However, these rates show strong inhomogeneity and anisotropy associated with anomalous mixing. It was found for nonlinear Lagrangian mixing times that for this paradigm helical coherent structure, 22% of the trajectory pairs were bounded by the initial separation (non-mixing) and 78% mixed in various classifications of convective dispersal. All non-local studies of 10,000 Lagrangian trajectories could be categorized into five classes of growth (decay) patterns which exhibit the effects of localized, finite helicity/momentum associated with this class of velocity field. A scalar dispersion simulation confirms that the “patch” of fluid near the origin is slowly mixing—on the diffusive time scale—and is convected “unmixed” when the influence of molecular diffusion is still not pronounced (short times relative to Pe=100).     

空气湿度对干燥过程的影响

以脉冲气流干燥过程为研究对象,利用数值模拟方法,分析了空气湿度对干燥过程的影响。     

Characterization of multiphase gas–solid flow and accuracy of turbulence models for lower stage cyclones used in suspension preheaters

This study involved the analysis and characterization of the multiphase flow phenomenon inside the lower stage cyclone separator used in the clinker burning process. The analysis was performed using both CFD and experimental research methods. Very few studies are devoted to such types of cyclone separators, which in addition to their basic functions are also responsible for the technological process. Due to the atypical working conditions of these cyclone separators, they are characterized with a complex geometry, which significantly differs from that of the traditional separators.Furthermore, the evaluation of the accuracy and level of reliability of the two models of turbulence closure—k-e RNG and RSM(RANS), and the LES. The results obtained led to the conclusion that for the lower stage cyclone separators, the LES model proved to be the most accurate(both in the case of forecasting the separation efficiency and pressure drop). The performance parameter(in particular the separation efficiency) values obtained for the RSM model were also characterized by high accuracy. The k-e RNG model was characterized by significantly larger deviations.