负载指数法在辽河流域水资源承载力评价中的应用

针对辽河流域水资源开发利用状况,选用负载指数分别评价了流域内四个水资源三级流域分区,并定量揭示了每个三级区内各城市的水资源利用程度与开发潜力,得出盘锦、沈阳、鞍山和营口地区负载指数最高.研究结果表明,现状年只有柳河口以上区间负载指数为Ⅱ级,其他几个地区负载指数已达到Ⅰ级,水资源开发利用程度已很高,未来负载状况将进一步恶化.     

浑河流域水资源合理配置研究

针对浑河流域水资源短缺和水污染问题严重的现状,同时考虑大伙房水库输水工程运行供水后的流域水资源供需变化情况,预测了2020年流域水资源的供需状况,并以流域供水净效益、流域总缺水量和流域协调发展指数为目标建立了流域水资源配置的多目标模型,采用大系统多目标总体遗传算法求解并提出了合理化建议,研究结果可为浑河流域水资源的可持续开发和综合规划决策提供理论支持和依据.     

基于耗水的盐城市水资源承载能力评价等级

盐城市在经济发展过程中暴露出一系列水资源问题。为了更好地了解区域社会经济发展阈值和水资源开发潜力,在分析水资源承载能力、水资源可利用量和耗水量之间联系的基础上,建立了基于耗水的水资源承载能力量化模型。计算了盐城市2015、2020年在75%来水频率下的水资源承载能力和各限制因素的承载潜力。结果表明,盐城市在2015年仍有一定承载潜力,在2020年将超载,主要原因为水量和氨氮排放。该结果为盐城市后续水资源开发利用提供了依据。     

汾河流域降水量时空分布变化对汛期的影响

合理地确定汛期是进行水库洪水调度的前提,对于流域、水库防洪及水资源的合理应用等具有重大意义。基于1957~2014年汾河流域13个气象站降水量资料,采用Mann-Kendall检验方法、Cramer法、Yamamoto法及Pettitt法检测突变点,以此突变点为分界线,采用扫描式滑动t值法研究突变年前后汛期的起止时间,采用PCA-Fisher最优分割法研究气候突变年前后汾河流域汛期分期的变化。结果表明,汾河流域降水量突变发生在1982年,汾河流域降水量突变年后多年平均降水量明显减少。在汾河流域降水量减少的同时,流域内降水量的年际分配越不均匀,突变年后各年内汛期起止时间波动幅度上升,从而导致流域内汛期提前并延长。     

基于集对指数势的流域水资源系统脆弱性影响因子分析

针对传统集对势定义的必要条件为对立度不等于零(不具有一般性)的问题,利用指数函数改进传统集对势,提出集对指数势的定义,建立基于集对指数势的流域水资源系统脆弱性影响因子分析方法,并对巢湖流域水资源系统脆弱性影响因子进行分析。结果表明,巢湖流域水资源系统脆弱性的影响因子主要包括水资源模数、水资源利用率、人均水资源量、工业废水处理率、人口密度、干旱受灾率、水利工程投资占GDP比例,可见利用集对指数势进行流域水资源系统脆弱性影响因子分析具有可行性。     

陕西泾河流域水资源评价

在实测水文资料的基础上,分析了陕西省泾河流域降水资源量、地表水资源量、地下水资源量、水资源总量、水资源可利用总量、水资源质量评价及水资源量趋势等,结果表明:陕西省泾河流域水资源总量6.32亿m3;泾河流域入境水量为14.01亿m3;陕西省泾河流域水利用总量为7.68亿m3。为陕西省泾河流域水资源管理及优化配置提供了参考。     

基于GIS的地图表达中国水资源公报主要内容及数据挖掘

鉴于目前出版的水资源公报多以文字表格的形式为主,表达方式僵硬,不能直观表达水资源的时空分布特点,难以挖掘出水资源公报中深层次的信息。以中国2001~2010年的水资源公报数据为例,建立了基于GIS的水资源公报数据库,对数据库中单要素和多要素进行图形化表达。即绘制各种专题地图,直观表达了多种水资源要素的时空分布,并可发现各要素之间存在的内在联系。然后,使用GIS对公报进行数据挖掘,建立了水资源负载指数和水资源承载指数模型,通过时空序列分析得出从表格文字型公报上不能直接获知的水资源与经济发展之间的制约关系和规律。结果表明,使用GIS发布水资源公报数据,以地图的形式直观全面地了解水资源时空变化,可以提高公报数据的易读性;基于GIS的数据挖掘,可使水资源公报成为智能分析系统。可见基于GIS的水资源公报系统是值得推广的一项新技术。     

新疆塔里木河流域干旱特征演变时空分析

基于塔里木河流域25个气象站1960~2011年的逐年降水资料,利用Z指数及相应的区域旱涝指标、M-K秩次相关法、R/S法、克里格插值法对该流域的降水量特征、干旱特征的变化趋势进行了时空分析。研究表明,流域由北向南多年平均降水量逐渐减小,年降水量变差系数逐渐增大;20世纪90年代前流域多以干旱为主,90年代后则多为偏雨,流域25个气象站中24个站的Z指数值存在上升趋势,并有11个站通过了90%置信度的M-K显著性检验,22个站点的Hurst值表明未来Z指数仍保持上升的趋势;流域有由干旱向湿润转化的趋势,转化趋势以源流区阿克苏河及中下游区域的站点最为明显;各年代Z指数值的空间分布状况有所不同,90年代的规律性最强。     

石羊河流域基流分割及特征分析

针对基流分割是水文预报中产汇流模型模拟、流域水文分析计算、区域水资源评价中经常遇到的问题,以石羊河流域为例,采用数字滤波法对流域的8条主要河流进行了基流分割和模型计算,分析了计算结果与流域水文特征值,探求了各指数指标的响应机制.结果表明,基流值与降水、地形等因素密切相关,该模型计算为流域水资源保护和合理分配提供了依据.     

基于均衡发展的郁江流域水资源优化配置

为使郁江流域水资源分配方案有利于沿岸区域之间的均衡发展,将基尼系数及纳什效率系数引入到水资源优化配置研究中,分别作为度量区域水资源分配公平程度和效率高低的指标,二者耦合作为区域均衡发展的度量标准。以经济效益和社会效益为目标,应用NSGA-Ⅱ对模型求解,得到郁江流域2020、2030年75%保证率一般节水模式下的水资源配置结果。结果表明,郁江流域平均缺水率为8.29%,比只有公平约束及只有效率约束时的缺水率均要小,且目标均达最优,考虑了流域各区域的协调发展,可为郁江流域水资源规划管理提供依据。     

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