摘要：Taking an oxygen enriched side-blown furnace as the prototype,a hydraulic model was established according to the similarity *** influence of three factors on the gas-liquid two-phase flow was analyzed,*** airflow speed,the submerged depth and the downward angle of the nozzle.A numerical simulation of the hydraulic model was carried out trying to find the suitable turbulence model which can describe the side-blown two-phase flow correctly by comparing the simulation results with the experimental *** experiment shows that the airflow speed has a great influence on the flow of the *** submerged depth of the nozzle has a relatively smaller influence on the penetration depth and the surface fluctuation height in the liquid *** the nozzle is at a downward angle of 15°,the penetration depth and the surface fluctuation height are *** is concluded that the numerical results with the realizable k-εturbulence model are the closest to the experiment for the penetration depth,the surface fluctuation height and the bubble scale.

摘要：根据一次表面热交换器(PSHE)的结构特点和流动传热规律,应用优化理论建立以结构质量、传热系数和压力损失为目标函数,以流道几何尺寸和流速为独立设计变量的PSHE多目标优化设计模型,利用线性加权和法将多目标向量极值问题转化为单目标标量极值问题,编程求解该优化数学模型.算例表明,优化设计分析方法可以避免板片几何尺寸选取的主观因素,获得最优性能的最佳设计.寻优分析有助于获得先进紧凑的一次表面换热器部件和高效的热动、化工联合装置.

摘要：Fast migration and efficient spatial separation of photogenerated charges in photocatalytic materials are indispensable to efficient solar water splitting ***,we construct a three-phase heterostructure of CdS/PbTiO_(3)/TiO_(2)by selectively depositing CdS and TiO_(2)at oppositely poled crystal facets of PbTiO_(3)using single-domain ferroelectric PbTiO_(3).The heterostructure has matching band edge alignments and strong interfacial connections at different *** heterostructure combines the interfacial electrical and ferroelectric fields because of their peculiar microstructures,which provide a strong driving force throughout the whole bulk to separate photogenerated *** two orders of magnitude improvement of visible-light-driven photocatalytic H_(2) production has been realized in CdS/PbTiO_(3)/TiO_(2)compared with bare PbTiO_(3)/TiO_(2),showing the efficiency of charge separation in the *** idea of combining ferroelectrics with potential light capture semiconductor provides a paradigm to accurately design charge migration pathways,bringing a step closer to efficient solar water splitting.

摘要：为了探索吸附式叶型设计特点,研究了一种将类别形状函数变换法(CST)方法和人工蜂群算法相结合,利用2D程序作为流场求解器,对吸附式叶型和抽吸方案进行耦合优化设计的新型吸附式压气机叶型设计方法,并且详细论证了CST方法用于吸附式叶型优化设计的可行性。研究结果表明:耦合优化设计之后在保证叶型强度未下降的基础上总压损失降低了65%,气流转折角增加了3°,气动性能得到较大的提升。针对所优化的进口高亚声速的吸附式叶型,通过适当改变叶型前缘处的型面,可以较好地控制气流马赫数,避免产生激波,从而防止附面层厚度增加,降低叶型损失。

摘要：为测量弹性减振元件传递动刚度,基于ISO 10846系列标准中的间接法测量原理,设计弹性减振元件传递动刚度测量台架;针对给定的有效测试频率上、下限确定阻滞质量块;基于有效测试条件,得到解耦弹簧选取依据。利用建立的台架试验研究某型挠性接管传递动刚度,测量结果在200~300 Hz频段内出现非正常波动。建立测量台架的有限元分析模型,数值研究表明,该波动是由于阻滞质量块与解耦弹簧之间的整体式过渡板存在局部模态。因此,对测量台架进行优化设计,结果表明,采用非整体式过渡结构可有效消除测量台架对测试结果的影响。

摘要：以高温合金低压涡轮叶片为原型,研究了采用SiC/SiC复合材料进行该型涡轮叶片结构设计的可行性。完成了SiC/SiC叶片的宏观设计、榫头设计和细节设计。计算分析了金属和复合材料涡轮叶片的变形和应力特点。对按设计制备的SiC/SiC叶片开展了拉伸强度测试,并在试验中监测了叶片的应变。计算结果表明:SiC/SiC叶片在额定状态下的伸长量低于原金属叶片;叶身叶根与缘板过渡处应力水平最高,但低于SiC/SiC复合材料的拉伸强度;榫头榫颈处有发生局部剪切破坏的风险。试验结果表明:该SiC/SiC叶片的断裂明显呈现出拉伸失效模式,以断裂转速计算的静强度储备系数约为1.3;所采用的SiC/SiC叶片结构设计方法可行,所制备的复合材料叶片也顺利通过了实验室条件下的静强度考核。

摘要：Real-time monitoring of the Bragg peak location of carbon ions is urgently required for the quality control of hadron therapy. In this study, we design an annular detector to monitor the Bragg peak location of carbon ions with Geant4 simulation. This 360° surrounding structure has a high detection efficiency for the small-dose situation. The detector consists of a multilayered collimator system and an Na I scintillator for prompt gamma counting. The multilayered collimator includes a lead layer to prevent unwanted gammas and the paraffin and boron carbide layers to moderate and capture fast neutrons. An inclination of the detector further diminishes the background signal caused by neutrons. The detector, with optimized parameters, is applicable to carbon ions of different energies. In addition, the scintillator is replaced by an improved EJ301 organic liquid scintillator to discriminate gammas and neutrons. Inserting thin Fe slices into the liquid scintillator improves the energy deposition efficiency. The Bragg peak location of 200 Me V/u carbon ions can be monitored by prompt gamma detection with the improved liquid scintillator.

摘要：二回路系统是船舶核动力装置的重要组成部分,其重量和尺寸是影响核动力装置合理布置的重要因素。随着船用核动力装置大功率、高推进速度的发展趋势,二回路系统重量和体积进一步增加,对核动力设备的设计安装带来困难,并严重影响船舶的机动性。本工作建立了二回路系统的数学模型,开发了相应的计算程序,并对影响二回路重量的设计参数进行了敏感性分析。以二回路重量最小为目标和在给定的约束条件下,采用混合粒子群算法对二回路系统进行了优化设计。研究结果显示,采用优化方案后,二回路系统重量减小了7%。最后对计算结果进行了分析,指明了二回路系统优化设计的方向。

摘要：探讨了直线超声电机夹持结构的设计方法。依据直线超声电机夹持结构的设计准则建立了在弹性夹持下的定子力学模型;研究了夹持结构的法向和切向弹簧刚度对定、动子在接触界面上的法向压力和切向摩擦力的影响规律,并通过有限元软件进行了仿真分析。最后,提出了一种切向刚度充分大的夹持方式,并设计了相应的梁式夹持V型直线超声电机。通过实验对比了设计的梁式夹持超声电机与柔性圆弧式夹持电机的输出特性。结果表明:相对原有的圆弧式夹持电机,新直线超声电机的输出力增大了1.7倍,速度增大了4.6倍,其最大输出力达到37N,最大速度达到1.4m/s。研究表明,提高切向弹簧刚度有利于提高电机的输出力和速度,设计的梁式夹持V型直线超声电机输出特性及稳定性良好。

摘要：随着经济的快速发展,环境污染、能源短缺的问题日益突出,发展新能源已是实现可持续发展的必然趋势。从发展需求的角度分析,本文提出了一种基于单片机的甲醇燃料电池控制系统,主要由燃料电池电堆系统、控制系统、辅助系统与机械系统构成。基于直接甲醇燃料电池(DMFC)电堆工作原理和评价单体电压一致性的研究基础,采用图形法确定系统最优运行工作参数。进一步在整体设计和详细设计两个层面进行系统开发设计。首先,在系统总体设计方案的基础上,阐述分析了控制系统电路以单片机STM32为核心的硬件电路设计与软件程序设计,经研究结果可知,该系统运行稳定可靠;其次,使用SolidWorks软件创建DMFC箱体3D模型,利用ANSYS Workbench建立DMFC仿真模型进行仿真分析,结合3D打印技术验证了整体设计参数的合理性以及最后产品与设计初衷的吻合性;最后,燃料电池系统在90 min的恒电流运行测试条件下,验证了该系统设计的正确性、合理性与可行性。文中设计为未来新能源产业相关燃料电池能源设备的研究开发提供了参考。