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。     

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.     

添加物对木耳液体菌种老化的影响

以黑木耳品种‘黑威15’为试验材料,研究营养物质对木耳液体菌种生长及老化的影响,筛选抗老化及易老化培养基,研究其抗氧化酶活性、底物降解酶活性、抗氧化物质及膜质过氧化程度变化规律。结果表明,①与对照组相比,添加磷酸二氢钾及VB1可延缓菌丝老化,且促进菌丝生长。添加硫酸镁对菌丝老化有缓解作用,但抑制菌丝生长。添加过量氮源可促进菌丝生长且加速菌丝老化。②与对照及易老化培养基相比,抗老化培养基中菌丝总蛋白含量、过氧化物酶、超氧化物歧化酶、抗坏血酸过氧化物酶、淀粉酶活性显著提高。表明活性氧自由基清除系统相关酶活性的提高对延缓菌丝老化具有重要作用。③SOD活性随菌龄增加而逐渐减小,与菌龄呈显著负相关。在抗老化培养基中,丙二醛含量随菌龄增加而降低,两者间呈显著负相关。在对照及易老化培养基中,MDA含量随菌龄增加呈上升趋势,两者间呈显著正相关。研究对分析木耳菌丝老化机制及解决液体菌种老化问题具有理论价值。     

Kaempferol alleviates the reduction of developmental competence during aging of porcine oocytes

Kaempferol (KAE) is a natural flavonoid present in different plant species and exhibits anti‐inflammatory, antioxidant, and anticancer therapeutic properties. In the present study, we investigated the influence and underlying mechanisms of KAE supplementation on porcine oocytes during in vitro aging. The results show that KAE treatment can alleviate the aging‐related reduction of developmental competence. We observed that the blastocyst production rate in aged oocytes treated with 0.1 μM KAE was significantly higher than in untreated aging oocytes (36.78 ± 0.86% vs. 27.55 ± 2.60%, respectively, p < .05). The KAE‐treated aging oocytes had significantly reduced levels of reactive oxygen species (p < .05). Furthermore, the mRNA levels of the embryonic pluripotency‐related genes Oct4, NANOG, and ITGA5 were significantly increased in blastocysts derived from KAE‐treated oocytes (p < .05). During excessive oocyte culture, KAE treatment maintained the mitochondrial membrane potential and reduced apoptosis; however, this was not observed in untreated aging oocytes. In conclusion, our results suggest that KAE treatment can alleviate the aging of porcine oocytes by reducing oxidative stress and improving mitochondrial function.     

线粒体与种子老化的关系

种子作为最基本的生产资料,其活力高低直接关系到农业生产的成败。关于种子老化机理的研究是种子科学研究的热点和难点。线粒体是真核生物细胞内重要的细胞器,是细胞能量合成和物质代谢的中心,也是活性氧产生的主要位点,且普遍认为,活性氧是导致种子老化的主要因素。种子老化过程中线粒体的典型结构逐渐被破坏,呼吸速率和氧化磷酸化效率降低,抗氧化功能发生改变,因此,本文主要概述种子的老化与线粒体结构、呼吸作用、抗氧化系统变化的关系,并阐述线粒体与细胞程序性死亡关系的研究进展,系统分析种子老化与线粒体变化研究中存在的问题及未来发展趋势,以期为研究种子老化的线粒体作用机理提供理论基础。     

Structural mechanics of wood composite materials I: Ultrasonic evaluation of internal bond strength during an accelerated aging test

This research attempts to observe indirectly the variation of internal bond characteristics for wood composite materials during accelerated aging test treatment using ultrasonic pulse-transmission techniques. Particleboard (PB) and oriented strandboard (OSB) were the representative specimens. The transit time of the ultrasonic wave propagating through the samples along the nominal length and thickness directions was recorded using an apparatus called PUNDIT (C.N.S. Electronic, London). The transit times were measured in the samples under an oven-dried condition after treating them with boiling water at different treating time stages, and the velocity was then calculated based on the transit time. Examination of the internal bond strength conducted on the same samples was done according to JIS A 5908. A study of the relations among springback, internal bond strength, and velocity indicated that a high correlation existed between ultrasonic velocity measured in the length or thickness direction and the internal bond strength for the PB specimen, but no significant correlation was observed between the velocity measured in the length direction and the internal bond strength for the OSB specimen. The results of this research suggested that ultrasound techniques can be applied to predict or evaluate the internal bond state of some wood-composite materials made of relatively small particles, such as PB especially, during accelerated aging test treatment processes.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, April 1997     

膨润土防渗毯用于渠道衬砌及其老化因素对力学性能的影响

膨润土防水毯(GCL)在渠道衬砌工程有较大的应用价值.为了测试膨润土防渗毯用于渠道衬砌其老化因素对力学性能的影响,以内蒙古河套灌区为研究区域,采用室内模拟及工程现场试验相结合,对5种老化因素的3种GCL力学性能影响进行了测试.结果表明:温度、湿度、紫外线照射都会对GCL的力学性能造成影响.高温对GCL力学性能影响大于低...     

水稻种子老化的生理生化与遗传学研究进展

膜系统损伤、DNA损伤、蛋白质合成能力下降和蛋白质损伤、活性氧过量积累是引起或加剧种子老化的主要原因.利用自然老化或人工老化处理方法,已报道的水稻种子耐贮性相关QTL除了第10染色体外,在其他染色体上均有分布.本文综述了水稻种子老化的生理生化与遗传学研究进展,同时分析了水稻耐贮性分子育种存在的问题,并对今后的发展前景进行了展望,以期为水稻种子耐贮性的基础研究与遗传改良提供参考.