气力输送中变径管道系统设计的研究

介绍了气力输送中变径管道的设计方法和主要参数（临界速度、管径、压降、气体流速、变径位置、变杆角）的确定。通过分析实验数据,说明采用逐渐增大管径的变径管道可以有效地降低输送管道中的气速、压损和能耗。     

化学反应速率模型对高温空气燃烧特性的影响

为了探讨更恰当的高温空气燃烧研究方法,本文从燃烧机理的角度,通过数值分析方法研究了化学反应速率模型对高温空气燃烧特性的影响,分别研究了单步有限反应速率模型、多步有限反应速率模型和涡旋破散模型.在多步有限反应速率模型中,考虑了多个反应步和逆反应,所以该模型结果中的温度比其他2种低,进而抑制了热力NO_x的生成,因此NO_x排放较低.单步有限反应速率模型与涡旋破散模型的结果基本一致,这与单步模型所用的一些经验常数是在常温下得到的有很大关系.研究结果验证,无论是对单步反应还是多步反应,建立的模型都有较好的适用性.     

基于Unity3D塔防游戏的设计与实现

基于Unity 3D引擎等技术进行开发了一款塔防游戏,实现的人物模型的创建与设置、游戏场景的布置、防守单位的创建、UI界面功能的完善、物品与背包系统的设计。本文对塔防游戏的设计,优化了场景,避免了游戏的崩溃与闪退,实现流畅的游戏体验。     

基于背景纹影技术的长空气间隙放电通道温度场测量

长空气间隙放电发展过程中伴随有介质热电离现象,准确获取温度场有助于深度分析间隙放电特性,背景纹影技术突破了传统纹影技术中透镜组镜面尺寸的限制,可获得大尺寸放电通道的温度分布特性。文中搭建了背景纹影测量系统,采集了放电发展过程中的背景斑点图集,利用PIV粒子图像测速技术分析得到了穿过放电通道的光线偏移量;基于Abel逆变换计算得到了光线偏移量对应的折射率,再根据热力学方程和理想气体状态方程定量重构出密度场和温度场,并以酒精灯火焰为参照物进行了温度校验,分析结果与热电偶实测结果基本一致。以1m棒–板空气间隙为研究对象,通过搭建的背景纹影实体测量系统观测间隙正极性放电发展过程,分析了放电通道温度的时空变化规律,结果表明间隙中部横截面温度分布在1 200 K左右,温度场呈轴对称分布且离通道中心越近温度梯度越大,整个通道温度自棒极而下逐渐降低。     

扇贝柱预处理工艺优化及干燥过程中品质变化评价

以栉孔扇贝柱为实验对象对其干燥前预处理工艺进行优化,得出最佳预处理工艺参数组合,对经过优化工艺预处理后的样品在干燥过程中外形、营养成分、流变学特性参数的变化进行评价。结果表明:栉孔扇贝柱干燥前预处理工艺参数组合为:扇贝柱在瓜儿豆胶和黄原胶的复配液中浸渍时间为1 h,复煮时间为1 min。在干燥过程中,工艺优化组扇贝柱样品水分含量变化缓和,扇贝柱干品柱形完好,表面裂纹细且少,不出现凹陷和散柱现象,外形评分较高。与传统预处理工艺相比,优化后的工艺预处理扇贝柱基本成分含量较高,营养成分损失少;流变学特性参数中硬度变化小而弹性、黏聚性和咀嚼性均显示出增长趋势,反映其具有弹性大、硬度小、黏结性好的特点,也说明改良的预处理工艺条件具有可行性。      

Dempster-Shafer证据理论在目标意图预测中的应用

为了准确对目标意图进行预测,以便我方及时合理地作出战术决策,采用D-S证据理论对目标意图进行预测。首先提取出影响目标意图预测的各个态势因素,然后分析每个因素的影响效果。在此基础上建立目标意图预测的数学模型,利用D-S合成法则将所有因素的影响进行综合,并计算出各个可能命题的概率赋值并给出相应决策。最后,通过仿真实例验证了该方法在目标意图预测中的可行性和实用性。     

Aerosol composition and source apportionment in Santiago de Chile

Santiago de Chile, São Paulo and Mexico City are Latin American urban areas that suffer from heavy air pollution. In order to study air pollution in Santiago area, an aerosol source apportionment study was designed to measure ambient aerosol composition and size distribution for two downtown sampling sites in Santiago. The aerosol monitoring stations were operated in Gotuzo and Las Condes during July and August 1996. The study employed stacked filter units (SFU) for aerosol sampling, collecting fine mode aerosol (dp<2 μm) and coarse mode aerosol (210 mass of particles smaller than 10 μm) and black carbon concentration were also measured. Particle-Induced X-ray Emission (PIXE) was used to measure the concentration of 22 trace elements at levels below 0.5 ng m⁻³. Quantitative aerosol source apportionment was performed using Absolute Principal Factor Analysis (APFA). Very high aerosol concentrations were observed (up to 400 μg/m³ PM₁₀). The main aerosol particle sources in Santiago are resuspended soil dust and traffic emissions. Coarse particles account for 63% of PM₁₀ aerosol in Gotuzo and 53% in Las Condes. A major part of this component is resuspended soil dust. In the fine fraction, resuspended soil dust accounts for 15% of fine mass, and the aerosols associated with transportation activities account for a high 64% of the fine particle mass. Sulfate particle is an important component of the aerosol in Santiago, mainly originating from gas-to-particle conversion from SO₂. In the Gotuzo site, sulfates are the highest aerosol component, accounting for 64.5% of fine mass. Direct traffic emissions are generally mixed with resuspended soil dust. It is difficult to separate the two components, because the soil dust in downtown Santiago is contaminated with Pb, Br, Cl, and other heavy metals that are also tracers for traffic emissions. Residual oil combustion is observed, with the presence of V, S and Ni. An aerosol components from industrial emissions is also present, with the presence of several heavy metals such as Zn, Cu and others. A factor with molybdenum, arsenic, copper and sulfur was observed frequently, and it results from emissions of copper smelters.     

空调水系统变流量节能控制分析

分析了变频调速水泵在三种控制(压差控制、温差控制、末端压差控制)方式下的运行过程、运行效果和节能效果,认为应综合考虑空调水系统的规模、负荷组成和分布、空调控制精度要求等因素选择最合适的控制方式。     

基于空气焓差法的空调机柜性能测试实验研究

本文以一种全热回收型空调机柜为研究对象,通过开关全热回收装置模拟了全热回收型空调机柜和普通空调机柜.利用DT?321s温湿度仪和AR866A风速仪测试了空调机柜的新风点、全热回收点、混合点、送风点的状态参数,基于空气焓差法计算了空调机柜的制冷量和能效比,并通过水流量计算方法进行了验证.研究结果表明:全热回收型空调机柜相...