【摘要】：土壤團(tuán)聚體是土壤結(jié)構(gòu)的基本組成單位。土壤結(jié)構(gòu)的穩(wěn)定性,大多數(shù)情況下是指團(tuán)聚體的水穩(wěn)定性,決定土壤行為、可產(chǎn)值、以及對土壤侵蝕和退化的抑制能力。關(guān)于土壤團(tuán)聚體穩(wěn)定性的測定,許多學(xué)者根據(jù)自己研究工作的需要,提出了各自的研究方法和測定方法。現(xiàn)有的利用超聲分散研究土壤團(tuán)聚體穩(wěn)定性定量評估系統(tǒng),試驗(yàn)過程中沒有針對土水溶液溫度快速升高的控制措施,受到土水溶液溫度上限的限制,每一次分散試驗(yàn)都不能持續(xù)過長時(shí)間,而一次試驗(yàn),不能保證土樣被完全分散,因此同一土樣完全分散需要多輪次試驗(yàn)。本文針對其存在的不足,進(jìn)行了如下改進(jìn)研究:(1)設(shè)計(jì)了一種新的雙層試驗(yàn)容器。針對普通50mL燒杯作為試驗(yàn)容器存在的不足,設(shè)計(jì)了一種新雙層試驗(yàn)容器,并在實(shí)驗(yàn)室條件下進(jìn)行了密封性、流通性、冷卻性能的測試,證明新的試驗(yàn)容器設(shè)計(jì)合理,達(dá)到了預(yù)期設(shè)計(jì)要求。為進(jìn)一步保證試驗(yàn)容器的可靠性,對其進(jìn)行保溫設(shè)計(jì),并對保溫性能進(jìn)行理論分析,結(jié)果表明試驗(yàn)容器熱損失只有系統(tǒng)總輸入能量的1‰,試驗(yàn)容器保溫性能良好。(2)設(shè)計(jì)了超聲分散測量系統(tǒng)。根據(jù)設(shè)計(jì)的試驗(yàn)容器,針對的研究配套試驗(yàn)設(shè)備和器件如超聲儀器、超聲探頭、數(shù)據(jù)采集系統(tǒng)、循環(huán)冷卻液體溫度測量探頭等,進(jìn)而集成設(shè)計(jì)了超聲分散能量測量系統(tǒng)。在實(shí)驗(yàn)室環(huán)境下分別進(jìn)行了超聲儀器空載損耗測試和超聲儀器振子深入液面不同深度輸出功率等性能測試,證明了試驗(yàn)容器控制溶液溫度的有效性,為土壤團(tuán)聚體分散能量測量提供快速高效的硬件平臺。(3)通過分析土壤超聲分散過程中能量的變化關(guān)系,確定了土壤超聲分散能量測量的計(jì)算方法,在實(shí)驗(yàn)室環(huán)境下對不同負(fù)載下超聲儀器輸入功率、溶液熱功率等分能量進(jìn)行了測試;在此基礎(chǔ)上對紅壤進(jìn)行測試計(jì)算,得出其總超聲分散能量約183J/g,與原系統(tǒng)多輪試驗(yàn)得到的結(jié)果相近,證明此方法可行。(4)進(jìn)行了超聲分散測量系統(tǒng)性能的進(jìn)一步驗(yàn)證。用超聲分散法和濕篩法兩種方法對比研究了不同土樣的穩(wěn)定性,并分析了兩種方法之間的關(guān)聯(lián)性和差異性,發(fā)現(xiàn)強(qiáng)穩(wěn)定性土樣用兩種方法分析的結(jié)果是一致的,即試樣土樣穩(wěn)定性:ZJJXCQ,但是弱穩(wěn)定土樣短時(shí)間內(nèi)被完全分散,從而導(dǎo)致結(jié)果出現(xiàn)差異,即弱穩(wěn)定性的土樣不適合用現(xiàn)有設(shè)備利用超聲分散法分析其穩(wěn)定性。即現(xiàn)有超聲儀器輸出功率對于弱穩(wěn)定性土樣來說,功率過大,這也可以作為一個(gè)判斷土樣是否適合使用現(xiàn)有超聲分散方法分析其穩(wěn)定性的方法。通過對土壤粒徑動態(tài)分布測量的試驗(yàn)設(shè)計(jì),并用HN、ZJ、CQ、JX四種土樣進(jìn)行了試驗(yàn),得出了它們的粒徑動態(tài)分布規(guī)律。HN、ZJ和CQ三種土樣都是在200s左右完成了土壤團(tuán)聚體的主要分散過程,而JX土樣在120s左右就完成了主要分散過程。再次驗(yàn)證了該試驗(yàn)系統(tǒng)的可行性。
[Abstract]:Soil aggregate is the basic unit of soil structure. The stability of soil structure, in most cases, refers to the water stability of aggregates, the determination of soil behavior, the value of production, and the ability to inhibit soil erosion and degradation. As to the determination of the stability of soil aggregates, many scholars have put forward their own research methods and methods according to the needs of their own research work. The existing quantitative evaluation system for the stability of soil aggregates by ultrasonic dispersion has no control measures for the rapid increase of soil water temperature during the experiment, which is limited by the upper limit of soil aqueous solution temperature. Each dispersion test can not last for too long, and one test can not guarantee that the soil sample is completely dispersed, so the complete dispersion of the same soil sample requires multiple rounds of tests. In this paper, the following improvements are carried out: (1) A new double-layer test vessel is designed. In view of the deficiency of ordinary 50mL beaker as a test vessel, a new double-layer test vessel was designed, and the sealing, flow and cooling properties of the new vessel were tested under laboratory conditions, which proved that the design of the new test vessel was reasonable. Meet the expected design requirements. In order to further ensure the reliability of the test vessel, the insulation design is carried out, and the thermal insulation performance is theoretically analyzed. The results show that the heat loss of the test vessel is only 1 鈥，

本文編號：2348574