中华民族形成时代新考

从中华民族族称由来的考释入手，论述了中华民族形成于帝舜有虞氏朝的历史过程。其最早的族称得名于舜的名字“华”。汉朝以后，又出现“中华”一词。近代，民族一词传入中国，始有“中华民族”这个近现代民族学的规范族称。但其族体的形成则在此前约五千年前。     

正确理解科学发展观的形成

“科学发展观的形成”是《毛泽东思想、邓小平理论和“三个代表”重要思想概论》第一章第五节“科学发展观”中的难点之一,该难点如何突破？教师应结合历史并充分利用《科学发展观学习读本》、胡锦涛总书记十七大报告讲清楚三个方面问题：一、什么是科学发展观;二、科学发展观形成的社会历史条件;三、科学发展观形成和发展的历程。     

分散体系级配数据形成过程及其教育教学意义

通过对粉体物料级配分析中沉降法实验的数据形成过程的解析,探索了级配分析的不同实验技术之间偏差的来源,理论知识在实践中的应用,以及科学的实验教学方式在人才培养中不可替代的功能和作用.     

航母编队电磁信号安全威胁分析

 介绍了航母编队面临周边的电子侦察威胁情况,并以航母编队穿越宫古海峡为例,仿真分析了其电磁信号受到的威胁程度。仿真分析结果表明：航母编队在公海进行训练、演习等军事行动时,面临着各种侦察设备的侦察威胁。     

银离子-热力复合冲击消毒对生活热水管壁生物膜的控制作用

针对建筑生活热水的生物安全性问题,对比研究了银离子、热力以及银离子-热力复合冲击消毒技术对生活热水管壁生物膜微生物的灭活效能.结果表明,银离子浓度和热水温度对管壁生物膜的细菌总数和总大肠菌群灭活效果影响显著,银离子浓度和热水温度越高,管壁生物膜的微生物灭活效果越好.银离子-热力复合消毒对管壁生物膜微生物灭活效果显著好于单一的银离子消毒或热力消毒;60℃热水、0.05 mg/L银离子、消毒60 min条件下的复合冲击消毒效果已接近单一的70℃热力冲击消毒效果,消毒后生物膜变薄或脱落,生物膜结构破坏明显.银离子-热复合冲击消毒显著,提高了建筑生活热水管壁生物膜微生物灭活效果,更高效地杀灭了病原微生物,是一种有应用价值的生活热水安全消毒和水质保障技术.      

多株吡啶高效降解菌的降解性能与生物膜形成特性的研究

以吡啶为目标污染物, 考察从焦化废水处理系统中分离的 12 株高效吡啶降解菌对吡啶的降解性能和生物膜形成特性, 以期为在废水处理系统中构建降解型生物膜提供理论参考。结果表明: 12株菌都具有较高的吡啶降解活性, 其中代表性菌株Pseudomonas sp. ZX01和Arthrobacter sp. ZX07降解吡啶的最适温度是35oC, 最适pH是7.0, 在初始吡啶浓度为100~2000 mg/L的范围内, 降解率均达到100%。不同菌株的生物膜形成能力差异明显, 胞外蛋白分泌量、胞外多糖分泌量和由鞭毛参与的游动能力与各株菌的生物膜形成能力之间存在显著的正相关关系。     

BEWARE OF THE BEACH HIDDEN KILLER--RIP CURRENT

离岸流是垂直于海岸线、向外海方向快速移动的强劲海流。对于海边的人员来说非常危险,没有经验的游泳者一旦被离岸流带离浅滩,很难与之对抗游回岸边,往往因力竭而溺水。每年海滨区域都有大量的溺亡事件与此相关,但有关离岸流的知识在公众的视野里仍比较缺乏。本文从流体力学的角度对离岸流的危害、形成、特征以及分类进行了简要介绍,并在如何防范离岸流、保障自身安全等方面给出了一些建议。     

Turbulent flow past a transverse cavity with inclined side walls. 1. Flow structure

The process of vortex formation in a cavity with inclined walls, which has a moderate aspect ratio, is experimentally studied, and the distribution of pressure coefficients is measured. The angle of inclination of the side walls ϕ is varied from 30 to 90°. It is found that the flow in the cavity becomes unstable in the range of inclination angles ϕ = 60–70°. Flow reconstruction occurs, which substantially alters the surface-temperature and static-pressure distributions. Large changes in these characteristics and their nonuniform distributions for these angles are observed across the cavity on its frontal wall and on the bottom. For small angles (ϕ = 30 and 45°), the pressure on the rear wall drastically increases, which leads to a small increase in pressure averaged over the entire cavity surface. __________ Translated from PrikladnayaMekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 5, pp. 68–76, September–October, 2006.     

On the instability of microjets

The instability of an axisymmetric viscous liquid jet in a gas or in a vacuum is examined using the interface formation theory. This model allows for variable surface tension at constant temperature, generalising the classical continuum formulation by using irreversible thermodynamics. Steady-state solutions are determined and found to be unstable to a travelling wave that propagates down the liquid jet, causing the jet to break-up into drops. The linear instability results are compared to those of the classical formulation. These are especially found to differ when the jets are on the micron scale. This will give rise to significantly revised predictions in some parameter ranges for the break-up length and droplet sizes produced by microjets. Comparisons with molecular dynamics simulations are also presented, with encouraging results. Finally, the dependence of the results on the initial conditions is discussed. PACS 68.03.Cd     

Experimental Study of the Rate of Unsteady Fluid Flow from a Prefilled Vessel

The variation of the flow-rate of a fluid flowing out of a prefilled cylindrical vessel through sinkholes with a diameter less than 0.1 of the vessel diameter has been studied experimentally. The study was carried out in both the presence and the absence of a vortex funnel around the sinkhole. In these experiments the vessel was filled in such a way that a funnel was formed only when a disk immersed in the fluid was rotated before the sinkhole was opened. The time dependence of the flow-rate is found for various initial heights and rates of artificial swirl. Four different outflow stages were detected. It is shown that for certain flow parameters there is a time interval on which the fluid flow-rate is independent of the column height. A critical rotation velocity W _0* below which (W ₀ < W _0*) an intense funnel is not formed is found. A limiting curve approached by all the flow-rate curves in the final stage of outflow is obtained.__________Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, 2005, pp. 113–121.Original Russian Text Copyright © 2005 by Shtarev.