掺石膏灰渣混合料的力学性质试验分析

为研究掺石膏灰渣混合料作为筑坝材料、路基材料等的工程适用性,对掺石膏灰渣混合料进行了物理力学性质试验,重点研究了五种脱硫石膏掺量的混合料的渗透性和抗剪强度。结果表明,混合料的渗透系数k、粘聚力c、内摩擦角φ均随脱硫石膏掺量的增加呈先增后减的趋势,且当石膏掺量均为30%时,渗透性最大,强度最高。故在实际工程中,可根据具体工程对渗透性和强度的要求选择不同石膏掺量的混合料。     

静三轴试验中固化疏浚泥的力学特性研究

为正确理解固化疏浚泥的力学性质,通过对固化疏浚泥进行固结不排水静三轴压缩试验,研究了围压和固化剂掺量对固化疏浚泥的破坏形式、应力—应变关系及抗剪强度参数的影响。试验结果表明,随着固化剂掺量的增加,固化疏浚泥的应力—应变关系由应变硬化型变为应变软化型;破坏形式由塑性破坏向脆性破坏过渡,而围压对其破坏形式无影响;固化疏浚泥的强度和抗变形能力均随着围压和掺量的增加而增大,但当围压小于土体内结构体的屈服强度时,围压对抗变形能力的影响可忽略;粘聚力和内摩擦角随固化剂掺量分别呈对数型和线性规律增长。     

一种新型柴油机清洁含氧燃料添加剂合成及其应用的研究

合成了一种新型含氧物质乙二醇单乙醚乙酸酯用作柴油机清洁燃料添加剂,并研究了其对柴油机排放和性能的影响,结果表明：在柴油机外特性下,掺加259／5此种添加剂CO排放平均下降约50％,掺加15％时平均下降约309／6,下降幅度随乙二醇单乙醚乙酸酯掺加量增加而增大;在2000r／min负荷特性下掺加此添加剂使CO和烟度排放下降,但掺加量的变化对排放影响不明显,而排放下降幅度均随平均有效压力增高而增大,NOx排放变化不显著。     

水泥固化污染土强度与变形特性分析

水泥固化常用于污染场地的治理,然而对于不同类型的污染物质,其相应的固化体物理力学性质亦不同。基于锌离子污染土样,通过室内试验分析了不同水泥掺量、不同重金属离子浓度条件下水泥固化污染土样强度及压缩特性。试验结果表明,水泥固化土的强度及压缩特性随龄期增加而不断增强,固化体的强度在前期提高较快,到后期增长较为缓慢;重金属离子浓度对水泥水化具有显著的抑制作用,为了保证重金属污染土的固化效果,水泥掺量至少应达到7.5%;固化体内摩擦角在养护期前期（7 d）有所增加,但在后期出现明显的下降趋势,其机理并无一个较为明确统一的理论。     

组合式滚筒冷渣机灰渣运动规律研究

针对多六棱管结构、多段组合式滚筒冷渣机,建立了灰渣料床理论运动模型,并采用EDEM颗粒离散元仿真分析方法,对灰渣料床的运动状态进行模拟。分析渣灰填充率、料床表面速率、渣灰活动区最大厚度与滚筒式冷渣机结构参数、运转工艺参数的相关性,结果表明:料床运动周期随转速ω(5 r/min≤ω≤10 r/min)的增加而近似线性减少;且料床运动周期T随填充率F(F≤50%)的增加而增加,随冷渣管内接圆半径R(R≤300 mm)的增加而明显增大。料床表面最大速率v_m,随ω增大而小幅提高,随R的增大而近似线性增大,但填充率F小于50%时,F的变化对料床表面最大速率v_m没有明显的影响。ω和F的变化对活动层最大厚度δ_m的影响不明显,但δ_m随R的增大而近似线性增大。六变形结构相对于圆筒形结构,料床的翻滚次数更多,灰渣的混合运动越强,更加有利于传热。     

粒径对氯、碱及碱土金属在生物质燃烧中析出的影响

研究固定床上稻秆和玉米秆在不同温度下燃烧过程中原料粒径对氯、碱与碱土金属(AAEMs)元素析出的影响。实验结果表明:随生物质粒径减小,K元素析出量逐渐增大,但不同生物质中K元素析出特性不同;粒径对生物质灰渣中MgO和CaO的含量变化有一定影响,同一种生物质,灰渣中MgO和CaO的含量变化规律相似;Cl元素析出量随粒径的减小而增加,当温度大于800℃时Cl元素释放完全;高温下生物质颗粒内的碱与碱土金属元素在不同的粒径下存在不同的物理化学反应,生成产物有所不同。     

掺砾膨胀土的侧限压缩增湿变形试验研究

为研究掺砾膨胀土作为填筑材料的湿化变形特性,采用常规固结仪对掺砾膨胀土进行了侧限压缩条件下的增湿试验,研究初始含水率和应力水平对增湿膨胀率及增湿后压缩性的影响。结果表明,增湿膨胀率随应力水平的增加而减小,存在从增湿膨胀转化为增湿体缩的分界应力。增湿后的压缩性受制样含水率及应力水平的影响显著,初始含水率越低,在加压的初始阶段,膨胀率随压力的增加降低得越快,且分级加压结束后的膨胀率越低;增湿时所处的应力水平越低,增湿稳定后分级加载时,试样的压缩变形量越大。研究成果为掺砾膨胀土作为填筑材料的可行性提供了参考。     

掺烧煤气协同分级配风对锅炉热量分配的影响

以煤粉掺烧高炉煤气和焦炉煤气的锅炉为研究对象,研究了高炉煤气与焦炉煤气热量掺烧比协同分级配风对锅炉主蒸汽、再热蒸汽吸热量的影响。结果表明:仅掺烧高炉煤气或焦炉煤气对辐射换热量和对流换热量的分配作用相反;同时掺烧高炉煤气和焦炉煤气时,主蒸汽、再热蒸汽吸热量均以对流换热为主,总吸热量均增加;高炉煤气二次风门开度增大会使再热蒸汽吸热量增加,而对于主蒸汽,对流换热量的增加未能抵消辐射换热量的减少;主蒸汽和再热蒸汽的对流换热量均随着煤粉二次风门开度的增大而减少,且随着分离燃尽风(SOFA)风门开度的增大而增加。     

SH固化黄土的土—水特征曲线试验

为提高黄土的强度和稳定性,采用新型高分子材料SH固化黄土,就固化黄土的击实、液塑限特性和土—水特征曲线进行试验研究。结果表明,固化黄土的最优含水率随SH掺量的增加而增大,而最大干密度则呈减小趋势;SH掺入后,黄土的液塑限、塑限指数均明显增大,但液限、塑性指数随SH掺量的增加先增后减;固化黄土的土—水特征曲线随着干密度的增大由陡变缓,干密度不变时,相同基质吸力下,SH掺量大的试样体积含水率大,固化黄土持水特性强,水稳定性高。     

含硅微粉变态混凝土浆液性能影响评价及时变演化规律

针对变态混凝土注浆施工中出现浆液堵管、扩散不均等问题，研究了不同硅微粉掺量对浆液的流动性、流变性、稳定性、强度和时变特性的影响。采用熵权理想点法综合考虑浆液工作性及经济性确定最优配合比。试验结果表明，掺加硅微粉可改善浆液泌水率，提高抗压强度。水胶比0.4时，掺硅微粉使浆液屈服应力与流动度减小、塑性粘度增大；水胶比0.5～0.7时，流变参数随硅微粉掺量增加而增大，浆液流变性与水膜厚度呈线性相关。随水胶比增大，硅微粉对浆液性能的影响逐渐减弱。浆液屈服应力随时间呈线性增长趋势，塑性粘度呈指数增长。基于熵权理想点法，可得到固定水胶比下的最优配合比方案。     

小型锅炉烟尘测试时锅炉出力的计算

锅炉烟尘测试时,必须对锅炉出力进行测试。但监测中,许多小型锅炉往往不具备相关的计量装置和仪表,为解决这一问题,文章提出了用烟气量和空气过剩系数来计算锅炉的出力的公式,在实际使用中,该方法简单易行,其结果和实测值具有很好的一致怀。     

Unerroric of control of mutual compliance of the efficiency of hydrogen engines of unmanned vehicles in the conditions of mass production

The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO₂ and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized.     

中国煤炭地下气化技术的发展

本文综述了煤炭地下汽化技术的国内外发展现状,对我国“长通道、大断面”煤炭地下气化新工艺给予了技术经济评述,并提出了发展煤炭地下汽化技术的政策建议。     

Review of theory of distortion and disintegration of liquid streams

Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined.     

MgO膨胀剂细度对MgO水化和水泥浆体膨胀的影响

基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁（MgO）,研究了该型MgO膨胀剂（MEA）细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析（TG DSC）分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。     

机车车轮多轴疲劳强度安全评定的研究

使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。     

Constructal optimization of the geometry of an array of micro-channels

This paper documents the geometric optimization of an array of circular and non-circular ducts. The optimization was carried out numerically using finite volume method. As optimal dimensions were independent of the array configuration, the numerical simulation was performed on a unit cell. Numerical optimization for circular, square and isosceles right triangle cross-sections of channels was performed. Based on the results of this investigation, some correlations were proposed to predict the optimal hydraulic diameter and dimensionless heat transfer per unit volume. In addition to examining the effect of pressure drop on these parameters, it was showed that among the different geometries of this study, square cross-section has the most efficiency for a given volume. The numerical results of the present study were compared with approximate results reported in the literature which a good agreement was observed.     

固体热辐射Yong性能分析

本文对漫灰均温物体在常物性条件下对外辐射传热的Ｙｏｎｇ值计算建立了数学模型。通过与物体内能Ｙｏｎｇ公式的数值计算比较,得出了辐射能量的Ｙｏｎｇ值不大于内能Ｙｏｎｇ值的结论。从初步的热射Ｙｏｎｇ值计算公式发现。Ｙｏｎｇ与物体表面辐射率有关。     

Measurements of concentration distribution of hydrogen jet using deflection of center of the laser spot

The main purpose of this work is to propose a new method to evaluate the concentration distribution of the hydrogen jet by using a He–Ne laser through the jet. This research attempts to apply the expression of concentration Gaussian distribution, the refraction formula of inhomogeneous refractive index medium, and the concentration inversion function to disclose the displacement of the center of the laser spot at different heights in the gas jet. The spot images of the laser beam passing through the gas jet at three vertical heights z = 10d, 20d, 30d, and different radial positions are obtained. The radial spatial asymmetry of the gas jet is also found in the experiment. Finally, the calculated concentration distribution curve and the fluent simulation curve, it is found that the two results are very similar. Our findings show that the error between the concentration distribution of this method and the simulated concentration distribution reaches 2.43%.     

Heat of vaporization of mixtures

General expressions for the heat of vaporization of mixtures at constant pressure; at constant temperature; and at constant pressure, temperature, and composition are proposed. The last one is related to the liquid-vapor interface where steady vaporization or condensation is taking place. Numerical examples by the proposed expressions are shown for binary mixtures of HCFC22(R22) and (HCFC123(R123) © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(1): 12–24, 1996