基于FPGA和DSP的超声波风向风速测量系统

本文研究了数字化超声风速测量系统,提出并实现了完整的系统设计方案。该方案的核心是基于现场可编程门阵列(FPGA)和数字信号处理器(DSP)的硬件系统架构和基于包络重心法的信号处理算法。该设计可实现超声信号的高速数据采集和复杂的信号处理算法。测试结果表明所实现的超声风速测量系统具有体积小、反应速度快、抗干扰能力强和分辨率高等优点,且具有成本优势,并保持较低的功耗。     

污泥的超声破解实验研究

本文在测量超声破解污泥试验所用反应器声场的基础上,主要研究了复频超声作用下,超声频率和换能器位置对污泥破解效果的影响。在此基础上采用两个同相换能器,以污泥滤液COD、NH₃-N、TP的增量,首次研究了复频超声破解污泥的效果,且详细探讨了影响复频超声破解污泥的影响因素（不同频率组合、不同功率组合、不同时间组合）。实验结果与理论分析符合较好,从而说明超声是一种有效的破解污泥的方法,进而对超声处理污泥的规律进行研究,这将为超声处理污泥提供一定的实验基础。     

Characterizing the properties of ultrasonics propagating on the surface of materials with defect by Laser-ultrasonics method

A laser ultrasonics method is used to characterize the propagation properties of surface wave traveling on the surface of materials with sub-surface defect in 2D.Linear and nonlinear propagation properties of ultrasonics caused by the defects have been detected in experiment. A theoretical model is proposed and used to study the linear and nonlinear properties of ultrasonics caused by the defect.The numerical results indicate that the nonlinear ultrasonic wave will be excited when a finite amplitude ultrasonics propagates on the surface of materials with sub-surface defect.The theoretical analysis confirms that the nonlinear wave is caused by the "clapping"of the interface of defect instead of the mode conversions of ultrasonics.     

The effects of ultrasound frequency and power on the activation energy in Si-KOH reaction system

The activation energy is the minimum amount of energy required to initiate a reaction. It is one of the important indexes for appraising a reaction. The chemical reaction rate is closely related to the value of activation energy, and reducing activation energy is propitious to promoting a chemical reaction. In the present paper, the relationship between the activation energy in Si-KOH reaction system and the ultrasound frequency and power has been discussed for the first time. The range of ultrasound frequency and power is 40-100kHz （interval by 20kHz） and 10-50W （interval by 10W）, respectively. The experimental clata indicate that the activation energy decreases with the increasing ultrasound power. Comparing with the activation energy without ultrasound irradiation, the results in our paper indicate that ultrasound irradiation could reduce the activation energy in Si-KOH reaction system and increase the reaction rate.     

玉米粕蛋白质提取工艺的响应面法分析

探讨提取玉米粕蛋白质的最佳工艺条件。在单因素试验的基础上,选取料液比(g·mL-1)、温度、NaoH浓度为响应因子,玉米粕蛋白质的提取率为响应值,实施3因素3水平的响应面分析,建立数学模型,得出最佳工艺条件。试验结果表明,玉米粕蛋白质的最佳提取条件为:料液比1:6.89(g·mL-1)、温度44.92℃、NaoH浓度0.078mol·L-1,在此工艺条件下玉米粕蛋白质的提取率可达到40.57%。     

超声法合成CePO4纳米线及发光性能研究

用CeO2作为铈源,采用可重复利用的H3PO4及非模板剂的情况下,用低温超声法成功合成了六方结构的CePO4一维纳米线材料。用X-射线粉末衍射(XRD)、透射电镜(TEM)和荧光分光光度计(FL)测试样品的物相结构、微观形貌、颗粒尺寸和发光性能;并研究超声时间和PO3-4/Ce3+摩尔比对产物的形貌和荧光性能的影响。结果表明:实验所做出的样品全部是六方晶系的结构,形貌都为一维纳米线,其纳米线长50~200nm,宽5~40nm左右;不同超声时间和PO3-4/Ce3+摩尔比的纳米线长径比不同,随超声时间的延长和PO3-4/Ce3+摩尔比增大纳米线出现团聚现象,产物在250~300nm处有宽的激发峰,在378nm处有一个发射峰,是属于Ce3+的5d-4f能级跃迁。     

超声强化过氧化氢/三氯乙酸催化氧化柴油深度脱硫研究

选择H₂O₂一三氯乙酸作为催化氧化脱硫反应体系,砜类氧化产物用极性溶剂从柴油中萃取分离,研究了剂油体积比、有机酸用量、氧化反应温度、氧化反应时间等工艺参数对脱硫率的影响。在此基础上,引入功率超声为反应提供能量,并考察了超声频率、超声功率、超声时间等因素对脱硫效果的影响,从而确定最佳操作条件为,反应温度70℃,反应时间60min,三氯乙酸与过氧化氢体积比为1∶1,氧化剂与柴油体积比为1∶10,超声频率40kHz,超声功率200W,超声时间30min。萃取后柴油脱硫率可达97.5%,脱硫油收率94.0%。     

生物质快速热解油水相溶液超声乳化特性

使用生物油水相溶液与0# 柴油乳化,筛选了四种常用乳化剂和一种助乳化剂进行复配乳化实验,考察了复配乳化剂型号、乳化剂用量、超声作用时间对乳化效果的影响。结果表明,六种乳化液超过30d不破乳,与0# 柴油相比,密度和热值相差不大,含水量3%以下,黏度增大约40%,pH值降低一半。因素分析法表明,水相溶液与柴油质量比和不同的水相溶液对乳化效果影响较大。探讨了乳化机理,认为生物油水相溶液中水、醛、酸、酮等极性组分化合物稳定地被乳化剂包裹在W/O型乳化液液滴中,生物油水相溶液中少量的乙酸乙酯、芳香类化合物等则增溶于非离子乳化剂胶束中。热力学分析表明,超声乳化作用比静置作用具有更大的熵增,乳化液更趋于稳定平衡状态。     

超声辅助溶剂萃取-原子荧光法用于土壤中汞的形态分析

建立了超声辅助溶剂萃取联用原子荧光法测定土壤样品中迁移毒性态汞中无机汞和有机汞的分析方法.实验优化了萃取溶剂种类,溶剂浓度,各种辅助措施和超声波振荡时间等各种萃取条件.方法的检出限为0.01 μg/L,相对标准偏差(n=11)为2.1%.方法已应用于珠江三角洲4个代表性菜园土壤样品汞形态分析.     

Synthesis and Self-assembling of Coumarin-based Low-molecular Weight Organogelators

Four coumarin derivatives(4a―4d) with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organogels in various organic fluids via ultrasound treatment or heating-cooling process, whereas compound 4c could only gel in a few mixed solvents and compounds 4a, 4b could not form organogel. The results from fluorescent and FT-IR spectra indicate that π-π interaction had an effect on the formatio...