【作者】 蔡卫明；

【导师】 朱松明； 汪宁； 贺惠农；

【作者基本信息】 浙江大学 ， 生物系统工程， 2013， 博士

【摘要】 随着Bio+X (Bio指生物学,x指物理学、工程学等其它科学)新思想、新科学的不断发展,工程学、物理学与植物学的多学科交叉与融合已经越来越受到国内外学术及工程界的重视。研究发现：适当的声波刺激对植物的生长与发育具有促进作用。这一研究结果为应用物理方法提高作物产量,减小传统化学农业由于化肥和农药的过量使用给生态环境带来的污染,实现生态农业的目标提供了一种新途径。然而,声波对植物生长的影响机制仍处于探索的初级阶段。相关的研究技术手段,专业的研究装备相对比较缺乏；声波对植物生长的影响机理在科学界还没有达到共识,理论支持不足。本文在对声波的产生与传递原理以及声波检测与控制的基本理论进行研究分析的基础上,研制了一套适宜植物-声频调控的实验系统,开发了相关的噪声屏蔽、声波发生及自适应校准技术,并提出了一种基于前馈补偿的闭环控制方法,实现了对设施环境中声波的模拟与控制。设计了一套声波刺激下的植物振动特性的测试平台。通过常见自然声的倍频程分析,得出各自然声的主要频率成分,并以此为基础,围绕探索不同可听声波对水培植物生长发育,吸收营养物质的变化规律,声波调控技术与自动控制技术在生产系统中的集成应用等方面开展了一系列的基础试验与应用研究工作,主要研究内容与结果如下：1.研制了一套适宜植物-声频调控的实验系统。对智能人工气候箱进行了分体式改造,植物培养箱与压缩机及循环风机分离,中间通过阻抗复合型消声器型结构导管进行隔音,使植物培养箱内部噪声比改造前降低了约28dB；开发了一套声波发生与控制系统,提出了一种基于前馈补偿的闭环控制方法,实现对设施环境中声波的自适应控制；对分别加载在人工气候箱中的纯音、组合频率声波、以及音乐声频等类型声波进行了测试,结果表明,不同类型的声波均达到了良好的校准作用。2.对植物野外生长环境中的几种常见的自然声进行分析得到：常见的鸟类晨鸣声的主频成分主要分布在2.0-4.1kHz；常见的蟋蟀和蝉鸣声的主频成分主要分布在3.0-4.0kHz；自然流水声及雨打荷叶声的主频成分主要分布在1.5-2.0kHz；通过对植物野外生长环境中各类声波特性的分析,发现2000Hz左右的频率是大多数植物野外生长环境中声波的主频中含有的频率成分。3.开展了声频调控对豆芽的发芽及生长、番茄的苗期生长等方面的研究工作。结果发现：声波处理可以缩短绿豆芽的发芽时间,随着声波强度及频率的增加,发芽时间呈现减小的趋势；不同声波对豆芽菜生长的影响不一样,声波对绿豆芽苗的茎部的生长有促进作用,但对其根部的生长有抑制作用。其中,声波频率在2.0kHz,90dB左右的声频对绿豆芽苗的生长影响最明显,可以提高豆芽的产量(茎部长度、鲜重等)；特定频率的声波处理可以加快番茄对氮元素的吸收,但对磷元素的吸收无显著影响,其中2200Hz的声波处理的促进相对较为明显。4.提出了一种声频调控技术与自动控制技术集成应用于微藻工厂化生产的技术实现方案。开发了一个微藻自动化生产控制系统,并通过微藻栽培试验探索了采用声频调控技术提高微藻生产产量的可行性。结果得到：声波处理可以加快微藻的生长速度,提高微藻的生产产量,其中2000Hz为主频的声波对产量的提高作用最为明显；不同声波对单位微藻生物质的含油量(即含油率)无明显影响,但是声波处理提高了微藻单位体积的产油量(含油率×生物量浓度),其中以2200Hz为主频的声波作用最为明显。更多还原

【Abstract】 With the continuous development of Bio+X science, multidisciplinary cross and integration among engineering, physics, and botany has been getting more and more attention by both engineering and academic community. Modern agriculture heavily relies on applications of fertilizers to promote plant growth and crop yield, but long-term fertilizer uses have brought severer environmental pollution. Reduction of chemical uses in crop production has been one of the major tasks for agricultural engineers. Recent studies have revealed that appropriate audible sound stimulation, a clean solution, has a great potential to improve plant growth and the quality of products. However, this new technology is still in the early stages of exploration. There was a lack of precise devices such as specialized research equipments and technical means to facilitate plant growth studies in the acoustic biology field. How plants sensing sound waves is still unknown. The mechanism of sound effects on plant growth haven’t reached consensus in scientific community because of insufficient theoretical support.This dissertation summarized and analysed the principle of generation and transmission of audible sound and the basic theory of acoustic detection technology. An audio frequency controllable experiment system was developed, a self-adaptive control method was put forward to reduce distortion characteristics of sound waves in facilities closed environment, and a measurement system was designed to detect vibration characteristics of plant under the stimulation of audible sound. Common audible sounds from Nature were analysed to obtain main frequency components, and based on the results, a series of basic tests and applied studies including sound effect on the growth, development, and nutrients absorption of hydroponic plant, and the integrated application of acoustic control technology and automatic control technology in production system were done. The major contents and results in this dissertation are as follows:1. An audio frequency controllable experiment system was created for experimental studies of audible sound effects on plant growth. The compressor and circulation fan of intelligent artificial climate box were separated from the plant cultivation chamber, and linked through ventilating duct with sound insulation. The internal noise was reduced by28dB. A control system was developed for audible sound generating. A solution was proposed for improving audible sound output based on closed-loop feed-forward control method. Results showed that pure tones, combination sound of pure tones, and normal music can be produced with high output accuracy.2. Different nature sound collected from environment of wild plants growth was analyzed. Results showed that:the acoustic frequency composition in most of nuture audible sound contained sound frequency of2.0kHz. The main frequency composition was from1.5kHz to2.0kHz in most of wild birds’chirm, from3.0kHz to4.0kHz in most of crickets and cicadas’ chirp, and from1.5kHz to2.0kHz in sound of trickling water and the sound of rain.3. Studies were carried out about the audible effect on the germination and growth of mung bean, the hydroponic Tomatoes’ early growth and absorption of N, P and other nutrients, etc. Experimental results indicated that the sound wave can reduce the germination period of mung bean and the mung bean under treatments of sound with intensity around90dB and frequency around2000Hz significantly increased in growth. Audible sound treatment can promote the growth of mung bean differently for distinct frequency and intensity. The volume of nutrient solution, total nitrogen, total phosphorus absorbed by tomato was exponentially increased versus growth time. Regression equation of the general formula can be represented as:y=y=aebx (a>0, b>0), where b can reflect the differences in abilities to absorb nutrients. The ability to absorb N or water of the audible sound treatment groups (N: b=0.0653; Water:b=0.0778) was better than the control groups (N:b=0.0591; Water: b=0.0765), but there was no difference between the ability to absorb P of the audible sound treatment groups (b=0.0649) and the control groups (b=0.0643), which indicated that audible sound with certain frequency can accelerate tomoto’s absorption of solution and N, but it have little effect on tomoto’s absorption of P. Audible sound with main frequency of2200Hz was a better one than audible sound with other main frequencies. 4. A technical proposal was made for Integration of plant acoustic control technology into an automated microalgae growth system for industrialized production. Test experiments were conducted to testify the automated microalgae growth system. The effect of the frequency of audible sound on biomass and algal oil production was examined. Results showed that audible sound with certain frequency can speed up the growth of microalgae and improve microalgae production. The mean biomass concentration of audible sound stimulation groups with main sound frequency of1100Hz,2200Hz, and3300Hz respectively increased by9.6%,35.5%, and10.7%than control groups. There was no distinct effect on increasing oil content in biomass of microalgae (PO) of after audible sound stimulation with main sound frequency of1100Hz,2200Hz, and3300Hz. However, the amount of oil production per unit volume of matured microalgae (PO) culture media increased through audible sound stimulation, and the maximum increase was about27.5%.更多还原