本文選題：功能-結(jié)構(gòu)模型 + 葉曲面模型��； 參考：《中國(guó)農(nóng)業(yè)大學(xué)》2016年博士論文

【摘要】：基于精確的植物結(jié)構(gòu)模型,可實(shí)現(xiàn)對(duì)植物冠層光能利用等的精確分析。本文通過(guò)獲取高精度的葉曲面信息,構(gòu)建了玉米和煙草的精確冠層結(jié)構(gòu)模型。為解決精確冠層結(jié)構(gòu)模型所帶來(lái)的巨大計(jì)算量的問(wèn)題,探索植物精確冠層結(jié)構(gòu)模型的合理簡(jiǎn)化方案,本文系統(tǒng)地評(píng)估了葉曲面網(wǎng)格簡(jiǎn)化對(duì)植物結(jié)構(gòu)及光截獲的影響�；跇�(gòu)建的植物結(jié)構(gòu)精確模型對(duì)兩種簡(jiǎn)化的植物結(jié)構(gòu)模型進(jìn)行了精度評(píng)估�；诰_的煙草冠層結(jié)構(gòu)模型,結(jié)合光分布模型和光合模型,進(jìn)行了大田煙草群體冠層結(jié)構(gòu)優(yōu)化的評(píng)估。主要內(nèi)容如下：1.進(jìn)行了玉米和煙草的大田實(shí)驗(yàn)。在玉米灌漿期和煙草打頂后,采用三維激光掃描儀精確測(cè)定了具有復(fù)雜形態(tài)的玉米和煙草葉片,構(gòu)建了高精度的三維葉曲面和植株結(jié)構(gòu)模型。采用頂點(diǎn)消除法和邊折疊法對(duì)掃描獲取的高精度的葉曲面網(wǎng)格進(jìn)行不同程度的精簡(jiǎn),根據(jù)選定的五個(gè)指標(biāo),系統(tǒng)評(píng)估了不同的簡(jiǎn)化方法和簡(jiǎn)化率對(duì)葉形態(tài)的影響；采用三維光分布模型模擬了作物冠層的光截獲,分析了葉曲面網(wǎng)格簡(jiǎn)化對(duì)光截獲模擬的影響。結(jié)果表明,對(duì)葉曲面網(wǎng)格進(jìn)行適度簡(jiǎn)化,基本不會(huì)改變?nèi)~片的結(jié)構(gòu)參數(shù),對(duì)葉片光截獲模擬沒(méi)有顯著影響。當(dāng)簡(jiǎn)化率過(guò)大后,葉片形態(tài)誤差和光截獲模擬誤差均顯著增加。與頂點(diǎn)消除法相比,邊折疊法能夠更好地保持原始葉片的曲面形態(tài)特征,但會(huì)損失更多的葉緣信息。2. 通過(guò)對(duì)精確葉曲面模型上的褶皺進(jìn)行逐步簡(jiǎn)化,構(gòu)建了兩種具有不同褶皺程度的簡(jiǎn)化葉曲面模型。在葉片和冠層兩個(gè)尺度上研究了褶皺對(duì)植物結(jié)構(gòu)與光截獲能力的影響。結(jié)果表明,葉曲面褶皺會(huì)顯著改變?nèi)~片形態(tài)和葉傾角。葉緣褶皺對(duì)葉傾角的影響與葉傾角的大小有關(guān)。當(dāng)葉傾角較小時(shí),葉緣褶皺會(huì)使葉傾角增加,當(dāng)葉傾角較大時(shí),葉緣褶皺則會(huì)使葉傾角降低。對(duì)于煙草葉片,葉曲面褶皺還能夠改變冠層的葉傾角分布函數(shù)。在葉片尺度上,葉緣褶皺和非葉緣褶皺均會(huì)使單個(gè)葉片的光截獲率降低,對(duì)于煙草葉片,其光截獲率最大降幅可達(dá)30%。在冠層尺度上,葉曲面褶皺能夠使太陽(yáng)輻射射入冠層的更深處,增加冠層中下部的相對(duì)光強(qiáng),從而使冠層的光分布更加均勻。3. 基于精確的煙草冠層結(jié)構(gòu)模型、光分布模型和光合模型進(jìn)行虛擬實(shí)驗(yàn)。通過(guò)調(diào)整株距、行距、行向和煙株留葉數(shù),構(gòu)建了不同的煙草群體冠層結(jié)構(gòu)模型,模擬了不同天空條件下各個(gè)煙草群體冠層的光截獲量和日潛在光合同化量。結(jié)果表明,種植行距增至110cm、株距增至60 cm后煙草群體的日潛在光合同化量不再明顯增加,種植行向?yàn)槟媳毕?±20。)時(shí)煙株群體的光截獲量最大。在煙株現(xiàn)有留葉情況下,去掉頂部2片葉和底部2片葉不會(huì)降低煙草群體的凈潛在光合同化量,且因改善了煙株的受光環(huán)境而有利于剩余葉片產(chǎn)質(zhì)量的提高。
[Abstract]:Based on the accurate plant structure model, the utilization of light energy in plant canopy can be analyzed accurately. In this paper, the accurate canopy structure model of maize and tobacco was constructed by obtaining high precision leaf surface information. In order to solve the problem of huge computational cost caused by accurate canopy structure model and to explore a reasonable simplification scheme of plant precise canopy structure model, the effect of leaf surface mesh simplification on plant structure and light interception is systematically evaluated. The accuracy of two simplified plant structure models was evaluated based on the constructed plant structure precise model. Based on the accurate model of tobacco canopy structure, combined with light distribution model and photosynthesis model, the canopy structure optimization of tobacco population in field was evaluated. The main content is as follows: 1. Field experiments on corn and tobacco were carried out. After filling period of maize and topping of tobacco, three dimensional laser scanner was used to accurately measure the complex shape of maize and tobacco leaves, and a high precision 3D leaf surface and plant structure model were constructed. The vertex elimination method and the edge folding method are used to simplify the leaf surface mesh with high precision obtained by scanning. According to the selected five indexes, the effects of different simplification methods and simplification rate on leaf morphology are systematically evaluated. Three dimensional light distribution model was used to simulate the light interception of crop canopy. The effect of leaf surface mesh simplification on the simulation of light capture was analyzed. The results show that the reasonable simplification of leaf surface mesh will not change the structural parameters of the blade and has no significant effect on the simulation of leaf light capture. When the simplification rate is too large, both the leaf shape error and the light interception simulation error increase significantly. Compared with the vertex elimination method, the edge folding method can keep the surface morphology of the original blade better, but it will lose more information of the blade edge. Two simplified leaf surface models with different fold degrees were constructed by simplifying the fold on the precise leaf surface model step by step. The effects of folds on plant structure and light interception were studied at leaf and canopy scales. The results showed that leaf surface fold could significantly change leaf morphology and leaf inclination. The influence of leaf margin fold on leaf inclination is related to the magnitude of leaf inclination. When the dip angle is small, the leaf edge fold will increase the leaf inclination angle, and when the leaf dip angle is large, the leaf edge fold will make the leaf dip angle decrease. For tobacco leaves, leaf surface folds can also change the leaf inclination distribution function of the canopy. In leaf scale, leaf margin fold and non-leaf fold can decrease the light interception rate of single leaf, and the maximum light capture rate of tobacco leaf can reach 30%. On the scale of the canopy, the leaf curved fold can make the solar radiation into the deeper part of the canopy, increase the relative light intensity in the middle and lower part of the canopy, and make the light distribution of the canopy more uniform. 3. Based on the accurate model of tobacco canopy structure, light distribution model and photosynthetic model, virtual experiments were carried out. The canopy structure models of different tobacco populations were constructed by adjusting the plant spacing, row direction and the number of leaves left in tobacco plants. The light interception amount and the potential daily light contract amount of different tobacco populations under different sky conditions were simulated. The results showed that the daily potential photocontractual amount of tobacco population increased from 110 cm to 110 cm and from 60 cm to 60 cm, but the row direction was from south to north (鹵20. 05). The light interception of tobacco population was the largest. The removal of the top 2 leaves and the bottom 2 leaves did not reduce the net potential light contract amount of tobacco population under the condition of the existing leaves of tobacco plants, and the improvement of the light receiving environment of the tobacco plants was beneficial to the increase of the yield and quality of the remaining leaves.
【學(xué)位授予單位】：中國(guó)農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：S513;S572

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相關(guān)期刊論文 前3條

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本文編號(hào)：2114665