建筑地基施工方法新探

随着土木工程建设持续、高速发展,地基处理技术发展很快,许多地基处理新方法应运而生。本文就一种新的建筑地基的施工的方法一旋喷注浆法的施工方法进行了阐述。     

旋转锥形水射流喷头的结构设计与相关分析

为了进一步改善工作效果,提高工作效率,尽可能减少能量损失,理论上探索适合磨料与水两相介质的加旋方式,设计出喷头结构,对旋转锥形射流喷头结构和射流在加旋段中的受力进行分析和研究．利用螺旋二相流相关理论初步讨论旋转锥形射流的运动特性。     

主流区风口模型在室内气流CFD模拟中的应用

分析了4类风口模型（即基本模型、盒子模型、N点动量模型、主流区风口模型）在计算流体动力学中的应用以及在实际工程案例中的运行情况.在环境舱内进行了足尺实验,利用全方位热风速表测量了环境舱内的气流速度和温度场,并与4类风口模型的模拟结果进行比较.结果表明：基本模型与盒子模型并不适用于结构复杂的送风口模拟;基于N点动量模型和主流区风口模型的流体速度在工作区的模拟值与实测值的相对误差小于20%;在主流区风口模型中,送风口附近的气体速度模拟值与实测值的最大相对误差小于15%.证明主流区风口模型相对于其他3类风口模型而言,对于结构复杂的送风口模拟更准确,应用性更强.     

一种塑编行业实用的喷水平织机纬线折边装置

综述了国内塑编行业的现状,分析了国内纺织行业织机折边装置的应用,介绍了塑编业喷水平织机纬线折边装置的结构与原理,总结了喷水平织机纬线折边装置的技术特点.     

Reaction thrust characteristics of high-pressure submerged water jet of cylinder nozzles

The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. The simulation of the flow field characteristics was conducted via the FLUENT computational fluid dynamics package. Effects of the inlet conditions and the nozzle dimensions on the reaction thrust of a water jet were addressed particularly. The reaction thrust experiments were performed on a custom-designed test apparatus. The experimental results reveal that a） the nozzle diameter and the inlet conditions exert great influence on the water jet reaction thrust; and b） for L≤4d0, where the nozzle is treated as a thin plate-orifice, the reaction thrust is independent of nozzle length; for L〉4d0, where the nozzle is treated as a long orifice, the reaction thrust can reach maximum under the condition of a certain flow rate. These findings lay a theoretical foundation for the design of nozzles and have significant value, especially for the future development of high-oressure water-let orooulsion technology.     

直馏航煤吸附脱硫醇的试验研究（Ⅰ）——试验方法及吸附剂的选择

随着原油的含硫量增加,直馏航空煤油馏分中的硫醇硫随之增加,原有的精制工艺已出现或潜在许多问题,如硫醇硫含量超标、博士试验不合格等质量问题,需进一步发展完善以适应生产需要。直馏航煤精制脱硫醇的方法有加氢法．继化氧化法和吸附法等。文章在自主安装的试验装置,进行静态及动态吸附试验研究。通过静态吸附试验,在13种吸附剂中选定复合氧化锌作为吸附剂。在此基础上,考察了吸附剂结构形状对吸附精制效果的影响。试验结果表明,粉状吸附剂脱除硫醇硫质量百分率最高（98．1％）,粒状次之（34．9％）,条状最差（21．8％）;内扩散阻力是影响吸附过程的重要因素。     

Effects of cryogenic cold air jet cutting on chip break in metal machining

1.IntroductionTherequirementsforenvironmentalprotectionaregettingstricterworldwide.Notonlythenaturalecologyandresourcesshouldbeconsideredinconservation,butalsotheenvironmentbeprotectedfrombeingsacrificedastheexpenseofproductivityboosts.Aconventionalmachiningprocessusedtotakeoilasthelubricantandcoolantforthesurfacesofmachinedtoolsandworkpieces,whichbroughtforthenvironmentpollution,andincreasedcostsonpost-treatingoftools,workpiecesandcuttingscrap.Asaresult,greenmachiningtechnologyfeaturingcleanp…     

Critical Heat Flux in Forced Convective Boiling with a Wall Jet

Thecriticalheatflux (CHF)intheforcedconvec tiveboilingwithawalljethasbeenstudied.KattoandIshii[1 ] measuredtheCHFofsaturatedwater,R1 1 3 ,andtrichloroethane (ρl/ ρg =2 0 3— 1 60 3)atatmosphericpressureforadownwardfacingplanewalljet,varyingthevelocityufrom 1 .5to 1 5m/sandtheheaterlengthLfrom 1 0to 2 0mm ,andproposedEq.(1 )topredicttheirCHFdata.　　　 qcoρghfgu=0 .0 1 6 4(ρl/ ρg) 0 .867(σρlu2 L) 1 / 3 (1 )　　KattoandHaramura[2 ] ,further,haveextendedtheirvelocityrangefromu =1 .8t…     

Simulation investigation on fluid characteristics of jet pipe water hydraulic servo valve based on CFD

Simulation investigation on fluid characteristics of the water hydraulic jet pipe servo valve (WHJPSV) is conducted through a commercial computational fluid dynamics (CFD) software package FLUENT. In particular, the factors to fluid characteristics of WHJPSV are addressed, which include diameter combination of jet pipe and receiver pipe, jet pipe nozzle clearance, angle between two jet receiver pipes and deflection angle of the jet pipe. It is concluded from the results that: (i) Structural parameters have ...     

航空业套期保值对策研究——以美国为例

文章介绍了美国航空公司应对油价波动的策略,并对其策略进行了深入剖析,从中得到两点启示,即套期保值是企业的核心竞争力,要选择适合的套期保值市场。