老芒麦种子人工加速老化条件的筛选比较

以4份不同发芽水平的老芒麦(Elymus sibiricus Linn.)种子作为试验材料,研究比较老化温度(39、41、43℃和45℃)和老化时间(1、2、3、4、5、6、7 d)处理对种子发芽率的影响,筛选确定老芒麦种子进行人工加速老化测定的适宜条件,并建立标准化的测定程序。结果表明:随着老化温度升高,Lot1、Lot2和Lot3样品种子发芽率均下降,且各处理间均差异显著(p<0.05),只有Lot 3在45℃条件下老化后发芽率下降的比例最低;Lot 4样品种子老化后发芽率较低,且45℃处理与其他各处理间均差异显著(p<0.05)。随着老化时间延长,Lot 1和Lot 2老芒麦种子老化发芽率不断降低,老化1、2 d处理与其他各处理发芽率间差异显著(p<0.05);Lot 3和Lot 4老芒麦种子老化至第4天后发芽率出现峰值。老化温度与老化时间互作效应与种子发芽率和休眠程度有关,且对老芒麦种子老化发芽率具有极显著(p<0.01)的影响。老芒麦种子人工加速老化处理的适宜条件为温度45℃老化2 d。     

发酵床陈化垫料腐解复合微生物菌剂筛选

为了探讨微生物茵剂对发酵床陈化垫料堆肥腐解的影响,以陈化垫料为原料,用实验室分离纯化得到不同类型的微生物菌株,选择搭配优势群体组成复合微生物茵剂,进行堆肥腐解试验。结果表明：添加不同配比比例的枯草芽孢杆菌,康宁木霉和高温放线茵能有效促进陈化垫料腐解,其中接种复合微生物茵剂（Kc：Kn：Gf=l：1：1）腐解效果最好,高温保持的时间达13d,堆肥结束时,纤维素降解率、木质素降解率、发芽率指数、C／N分别为47．6％、30．2％、98．5％、18．sN,大肠杆菌未检出。     

Interactive Effects of CO2 and O3 on the Growth of Trisetum flavescens and Trifolium pratense Grown in Monoculture or a Bi-Species Mixture

SUMMARY

Golden oat grass (Trisetum flavescens L.) and red clover (Trifolium pratense L.) were grown as monocultures or bi-species mixtures under controlled conditions and exposed to ambient (350 ppm) or elevated (580 ppm) CO₂, with or without addition of O₃ (diel profile with 150 ppb maximum). Shoot biomass measurements after the initial growth and two re-growth periods were used to determine the specific responses of both species, and the difference in the specific response between monocultures and mixtures. T. pratense was much more responsive to CO₂, O₃, and their combination, compared to T. flavescens. In the case of O₃ but not of CO₂, the difference in sensitivity between species was larger in mixture than in monoculture. In contrast to elevated CO₂, O₃ significantly reduced the root:shoot ratio in the mixture, which could explain the increasing negative effect of O₃ on clover with progressing harvests.

The relative CO₂ stimulation of T. pratense and of the cumulative mixture shoot biomass was larger in the presence than in the absence of O₃, which was due to an almost complete protection from O₃ stress by elevated CO₂. In the mixture, the fraction of T. flavescens was small and increased during the experiment; this increase was most pronounced with O3, but any change in mixture biomass was dominated by the response of T. repens.

The results confirm that in grass/legume mixtures legumes are most sensitive to elevated CO₂ and O₃, but the magnitude of specific responses depends on canopy structure and of plant development. Elevated CO₂ minimizes the negative impacts of O₃ stress on above- and below-ground plant growth.     

臭氧氧化对奶牛场沼液中磷形态转化的影响

为了提高沼液磷的回收效果,研究了曝气种类和曝气条件对奶牛场沼液磷形态转化的影响。结果表明:在参考曝气条件下,与氮气和空气相比,臭氧能更大程度地降低颗粒态磷和交换态磷含量,并大幅度提升溶解性正磷酸盐含量。臭氧曝气的优选条件为沼液初始pH值为6、臭氧发生量为10 g·h~(-1)、氧化时间为60 min,曝气后沼液中溶解性正磷酸盐浓度提高了76.12%,溶解性正磷酸盐占总磷比例提升20.75%。臭氧氧化可以促进颗粒态磷和交换态磷向溶解性正磷酸盐转化,从而促进沼液磷的回收。     

臭氧处理对番茄和黄瓜种子萌发的影响

【目的】阐明臭氧处理对陈番茄和黄瓜种子萌发及种子活力的影响。【方法】以放置1年的陈番茄和黄瓜种子作为研究对象,用80,120和160 mg/m~3的臭氧分别处理番茄和黄瓜种子30 min,研究不同臭氧处理对番茄和黄瓜种子表面微生物菌落数以及种子发芽势、发芽率和活力(SOD、POD活性和MDA含量)的影响,并对各生理指标的相关性进行分析。【结果】用160 mg/m~3的臭氧处理30 min,番茄和黄瓜种子表面微生物的抑制率均达到最大值,分别为97.4%和99.5%。用80 mg/m~3的臭氧处理30 min,番茄种子的发芽势、发芽率、SOD活性和POD活性均达到最大值,分别为68.0%,94.5%,193.8 U/g和2 193.4 U/g,MDA含量达到最小值,为19.4 nmol/g。用160 mg/m~3的臭氧处理30 min,黄瓜种子的发芽势、发芽率、SOD活性和POD活性均达到最大值,分别为96.5%,99.5%,160. 3 U/g和2 300.4 U/g,MDA含量达到最小值,为10.8 nmol/g。臭氧处理后,番茄和黄瓜种子SOD和POD活性与发芽势和发芽率呈显著正相关,而MDA含量与发芽势和发芽率呈显著负相关。【结论】适宜浓度的臭氧处理后可以抑制种子表面微生物的生长,提高种子的发芽率和活力。     

臭氧在醋酸溶液中溶解及稳定性研究

【目的】臭氧在水中的溶解度很小,极不稳定,易分解,且寿命很短,其半衰期仅 20~30 min。考 察臭氧在醋酸溶液中的溶解特性,以提高臭氧的溶解度与稳定性。【方法】在水中加入少量醋酸,采用碘量法 测定醋酸溶液中臭氧的浓度,间接得出臭氧在醋酸溶液中的溶解度;通过控制变量法,改变单一变量,探索醋 酸浓度、温度、配制醋酸溶液的水质、通入臭氧后的放置时间、通入臭氧气体的时间等因素对臭氧在醋酸溶液 中的溶解度的影响,探讨臭氧在醋酸溶液中溶解度最高的最佳条件。【结果】当醋酸浓度为 0.6 mol/L、温度低于 5℃、 通入臭氧处理 60 min 左右,臭氧溶解度最高,达 2.37 mg/L。试验还显示,水质越纯时,臭氧溶解度越大。【结论】 在水中添加少量醋酸能够提高臭氧在水中的溶解度与稳定性。     

玉米种子人工老化过程中生理特性与种子活力的变化

种子贮藏过程中各项活力逐渐降低,即种子的老化。老化不仅影响种子萌发与幼苗的生长,也会影响到后期植株的产量与品质。以玉米自交系昌7-2、杂交组合郑单958和农大108的F1种子为试验材料,通过人工加速老化的方法,对3个品种(系)的玉米种子人工老化过程中生理特性与种子活力的变化规律进行了分析。结果表明,玉米种子的发芽势、发芽率、发芽指数和活力指数均随老化时间的延长而降低;过氧化物酶(POD)的活性随老化时间的增加而降低,与种子的各项活力指标呈正相关,其中昌7-2与各项活力指标的相关性、郑单958与活力指数的相关性达显著水平;浸出液的相对电导率和丙二醛(MDA)含量随种子的老化时间而升高,与种子的各项活力指标呈负相关,其中昌7-2和农大108的相对电导率、昌7-2的MDA含量与各项活力指标的相关性均达到极显著水平,郑单958的相对电导率与活力指数和MDA含量与各项活力指标的相关性也达到显著水平;玉米种子的发芽率和活力指数随着老化时间的增加呈现一个先缓慢后加快的下降趋势;农大108的抗老化能力较弱,昌7-2和郑单958表现出较强的抗老化能力。     

Preparation of a dicyandiamide-contained novel insulation paper and an experiment on the thermal aging characteristics of relevant oil-paper insulations

In order to study the influence of dicyandiamide added into the insulation paper on the oil-paper insulation during the aging process.The insulation paper containing dicyandiamide and the insulation paper without any stabilizer are prepared. They are immersed in transformer oil separately and placed in the aging chamber with predefined temperature of 130℃ for 31 days to perform thermal aging experiment of oil-paper insulation. The specimens are periodically sampled and some parameters are measured like the degree of polymerization(DP), the breakdown voltage, the nitrogen content, the acidity of insulation oil, and UV-Vis spectrum. The results show that the insulation paper added with dicyandiamide has a distinct anti-aging and anti-breakdown effect and the DP is 58% higher than that of blank sample at the later stage of aging. In the aging process, decline of the nitrogen content of insulation paper is not serious. The oil-paper sample containing dicyandiamide has a far lower value of acidity than that of blank sample, besides the oil color is deeper. Dicyandiamide in the insulation paper improves not only the anti-aging and anti-breakdown properties, but also the performance of oil in the aging process.     

不同土壤处理对番茄根结线虫防治效果及产量的影响

为了建立安全、高效、绿色的蔬菜根结线虫防治技术,研究了"臭氧水+生物菌肥+噻唑膦""臭氧水+生物菌肥+阿维菌素""臭氧水+生物菌肥""生物菌肥+噻唑膦"及生物菌肥5种土壤处理对设施番茄根结线虫病的防治效果和产量的影响。结果表明:以臭氧水为基础组配的土壤处理防治根结线虫,对秋冬茬、冬春茬2茬番茄根结线虫病的防效均在90.0%及以上,对番茄产量的恢复或增加效果明显,其中"臭氧水+噻唑膦+生物菌肥"土壤处理对番茄根结线虫防治效果最好,"臭氧水+生物菌肥"土壤处理最为安全、经济,且防治效果较好,建议广大菜农积极应用。