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61.
部分菊科入侵种种子(瘦果)的萌发能力和幼苗建群特性 总被引:3,自引:0,他引:3
对入侵种种子生物学各方面的了解有助于更好地预测入侵趋势和评估可持续管理的策略.研究通过对部分菊科入侵种种子(瘦果)进行的室内萌发实验和土壤埋藏实验,通过与相关研究的对比和分析,对这些入侵种的萌发能力和幼苗建群特性进行了研究.10个入侵种种子室内萌发实验的结果表明,在25℃、12h光照的情况下,除钻形紫菀和一年蓬以外,被研究的其它8个种的终萌发率超过了50%,而且都显示出早期快速萌发的特点.用SPSS的曲线拟合工具对10个种的累积萌发趋势进行了曲线回归分析,对应的最佳模型均为三次曲线方程.不同土壤埋藏深度下幼苗出苗实验的结果表明,菊科8个入侵种的种子在表土的出苗率均最高,随着覆土厚度的增加,种子的出苗率逐渐降低,当覆土厚度超过3 cm以上时,所有种子均不能出苗.种子在不同的埋藏深度的出苗情况与种子的大小有关,较大种子破土能力相对较强;种子在不同的埋藏深度的出苗情况与种子本身的萌发能力也相关.土壤埋藏期限的实验结果表明,随埋藏时期的增加,小蓬草、苏门白酒草和一年蓬3个人侵种种子的活力逐步降低,在土壤中埋藏12个月后,其活力分别为21.34%、18.15%和27.38%.这些入侵种较广的种子萌发温度适应范围和高萌发率为防除工作带来了困难.在生产上,可通过不同时期的翻耕、将种子深埋等措施减少这些入侵种的危害. 相似文献
62.
Biochar, is a low-cost material that can be used as an alternative adsorbent for the removal of heavy metals. In this study, a low-cost and efficient adsorbent synthesised from Jatropha curcas seeds was used for the uptake of Cu2+ from aqueous solutions. The as-prepared adsorbent was characterised by scanning electron microscopy and Brunauer–Emmett–Teller analysis post calcination at 500 °C, its BET surface area and total pore volume were 39.62?m2?g?1 and 0.049?m3?g?1, respectively. Subsequently, the effects of initial pH of the solution, contact time, and adsorbent material dosage on the adsorption of Cu2+ by the prepared adsorbent were investigated. The as-prepared adsorbent exhibited a high performance, with a maximum adsorption amount of 32.895?mg?g?1 for Cu2+ at pH 5.0 and 25 °C, owing to the presence of ?OH, C=O, C–O, Si-O-Si, and O-Si-O on its surface. The predominant Cu2+ adsorption mechanism was assumed to be ion exchange. Notably, the Cu2+ adsorption could attain equilibrium within 90?min. In addition, the fact that the Langmuir model was a better fit than the Freundlich model for the isotherm data of Cu2+ adsorption by the as-prepared adsorbent suggested that the adsorption of Cu2+ was a monolayer adsorption process. 相似文献
63.
Junguo HE Guangming ZHANG Haifeng LU 《Frontiers of Environmental Science & Engineering》2010,4(3):334-339
The conventional treatment method of soybean wastewater is expensive and generates waste sludge that requires further handling. Purple nonsulfur bacteria (PNSB) wastewater treatment is a clean technology and can generate single cell protein while degrading pollutants. A wild strain of PNSB, Rhodobacter sphaeroides Z08, was isolated from local soil and was used to treat soybean wastewater. To develop a cost-effective process, the work was performed under natural conditions without artificial light, aeration, nutrients addition, or pH and temperature adjustment. The results showed that the wild strain Rhodobacter sphaeroides Z08 could grow well under natural conditions. The growth curve showed two quick-growth periods and a turning point. The Z08 treatment of soybean wastewater was zero order reaction and COD reduction was 96% after 10 d. The major byproducts of the process were C2-C5 organic acids, predominantly butyric acid. No alcohol was found in the effluent. The initial COD/bacterial-mass ratio (F/M) had a significant effect on soybean wastewater treatment efficiency. When the initial F/M was lower than 10 mg-COD/mg-bacteria, a sufficient amount of time to achieve 90% of COD reduction was only three days. The Z08 biomass yield was 0.28g·g−1, and the bacterial protein content was 52%. 相似文献
64.
65.
针对大豆深加工高浓度有机废水厌氧出水的特点,采用移动床生物膜反应器-沉淀池-厌氧池(MBBR-SA)工艺进行处理,重点考察了其COD去除、脱氮以及污泥减量化的性能。处理前厌氧出水水质参数为COD 1 350~1 851 mg/L、TN 45~73 mg/L和TP 35~55 mg/L。结果表明,经过70 d的运行,在最佳水力停留时间(HRT)1.68 d与最佳回流比0.75条件下,出水平均COD、TN和NH4+-N浓度分别为91.5、12.4和11.4 mg/L,分别达到了《城镇污水处理厂污染物排放标准》二级标准、二级标准和一级B标准,其平均去除率分别为96.0%、87.4%和88.3%;该工艺未排放剩余污泥,其表观污泥产率为0.13,比MBBR降低了43.5%,具有明显的污泥减量化特性。 相似文献
66.
对大豆膳食纤维进行了羧甲基化改性,并利用红外光谱(FT-IR)和扫描电镜(SEM)对其结构进行了表征.研究了羧甲基化大豆膳食纤维用量、吸附时间、吸附温度、溶液pH值等因素对其吸附亚甲基蓝、结晶紫和品红效果的影响.结果表明,当吸附温度为25℃、羧甲基化大豆膳食纤维浓度为20 mg/L、溶液pH值为6.8和吸附时间为60 min时,羧甲基化大豆膳食纤维对亚甲基蓝、结晶紫和品红的去除率分别达到96.4%、95.6%和94.7%.另外,此吸附过程较好地符合Langmuir和Freundlich等温吸附模型. 相似文献
67.
Ziyuan Zhou Weian Zhang Dafeng Sun Liwei Zhu 《International Journal of Green Energy》2016,13(12):1185-1192
As a potential hydrocarbon production method, the hydrocracking of soybean biodiesel, using a commercial petroleum hydrocracking catalyst, was studied. Experiments were carried out in a 1,000 mL, high-pressure autoclave for 2–4 hr over the temperature range of 200–280°C under an initial hydrogen pressure of 10 MPa. Hydrocracking of soybean biodiesel produced n-paraffins in the C8–C17 boiling range, which includes both green gasoline and diesel. Both pressure and temperature play important roles in the transformation of soybean biodiesel. Hydrocarbons can be formed above 220°C with a liquid yield of 81.76%. The n-alkanes content of the liquid product reached 32.29% at 280°C, with 88.32% C11–C14 selectivity. In addition, hydrocracking results in many changes of catalyst such as physical properties, morphology, etc. For the used catalyst, the concentrations of Ni and C increased, and the pore channels were significantly reduced. 相似文献
68.
SO2和酸雨对大豆的单一及复合效应 总被引:12,自引:3,他引:9
应用开顶式熏气装置研究了SO2和模拟酸雨对大豆的单一与复合作用效应.结果表明:经SO2和酸雨处理后,大豆叶绿素含量减少、膜透性增加,叶液pH值降低,但SO2和酸雨对叶片含糖量的影响不明显;SO2+酸雨对大豆的复合作用效应明显大于SO2或酸雨单因子作用效应;SO2+酸雨对大豆的复合作用效应与SO2熏气浓度,酸雨pH和暴露时间有密切关系. 相似文献
69.
静电场和聚乙二醇等处理对大豆种子抗吸胀冷害的促进作用的比较 总被引:1,自引:0,他引:1
用正、负高压静电场(HVEF),聚乙二醇(PEG),氯化钙(CaCl2)和二甲基亚矾(DMSO)等方法预处理大豆种子,比较种子抗低温吸胀冷害的能力结果表明:负高压静电场处理能促进膜相转变或损伤修复,并能在低温吸胀时减少无机离子,有机大分子物质的外渗;还能提高种子内自由基清除酶系的活性,促进糖原和贮存蛋白的代谢及生长调节物质的水平比较几种处理方法的效果表明:高压静电场处理主要提高自由基清除酶系和基础代谢酶的活性,而对吸胀时的膜损伤修复的促进效果较小;聚乙二醇和氯化钙则在促进种子吸胀时的睦相转变和膜损伤修复方面有显著作用所有的处理方法均在不同程度上抑制羟自由基(HO)的产生,从而减轻膜脂质过氧化的伤害. 相似文献
70.