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41.
不同贮藏时间的普洱茶香气成分分析 总被引:23,自引:0,他引:23
采用顶空—固相微萃取技术提取不同贮藏时间的普洱茶香气成分, 经气质联用分析鉴定, 结果表明, 贮藏30 年、25 年、6 年和当年生产的茶样中, 萜烯化合物及其衍生物含量分别为51.42%、89.15%、74.10%、39.72%。但陈茶与新茶中的萜烯化合物及其衍生物的种类却有明显的不同, 陈茶中以反-丁香烯为主, 在贮藏30年、25年、6年茶样中的含量分别达36.78%、66.98%、56.08% , 而当年生产的样品以愈创木烯为主, 其含量达33130% , 反- 丁香烯含量仅为1102%。与当年生产的茶样相比, 陈茶香气成分种类和含量都较少, 贮藏30年、25年、6年茶样分别鉴定出23、24、22种香气化合物, 而当年生产的茶样共鉴定出36种化合物。 相似文献
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蔡祖聪 《农业环境科学学报》2023,42(2):237-241
本文简要地介绍了2022年《农业环境科学学报》刊出论文的总体情况和农业环境领域当前的研究热点,重点评述了土壤环境、环境健康与农产品安全、废弃物处理及资源化利用、农业与全球变化领域刊出的论文,总结了当前这些领域重点关注的科学问题及取得的主要进展。 相似文献
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Organic amendment is a proved method of improving soil physical properties thus affecting runoff and soil erosion. Urban wastes are a potential source of organic matter and their use would also be a convenient way of disposing of them. A field experiment was conducted from October 1988 to September 1993 in a semiarid Mediterranean site to determine the effect of applying several rates (65, 130, 195 and 260 Mg ha−1) of organic urban solid refuse (USR) on total runoff and soil loss. At the lowest rate, total runoff decreased by 67 per cent compared to the control plot. The decrease was 98 per cent when the highest rate was used. The lowest rate reduced total sediment loss by 81 per cent and the highest rate of 99 per cent. The decrease in soil erodibility at the different USR rates varied from 76 to 95 per cent depending on the year for the lowest rate and between 90 and 99 per cent for the other rates. Clear differences in the hydrologic and erosion responses were found between the eight initial rainfall events (during the first 10 months of the experiment) and the remainder of the events. The causes of such differences were due to the initial tillage of the soil by rotovation and the growth of natural vegetation in the treated plots. The mechanical effect of tillage reduced runoff and increased soil erodibility, although the effect was short‐lived. The addition of USR reduced runoff but lasted longer. An applied rate of 90–100 Mg ha−1 could be considered suitable for application in semiarid zones. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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Asahi HORINAKA Yo-Han KIM Atsushi KIMURA Eiji IWAMOTO Tatsunori MASAKI Toshihiro ICHIJO Shigeru SATO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(7):1098
We investigated changes in the predicted functions of the rumen bacterial community in Japanese Black beef cattle during fattening. Nine cattle were fed a high-concentrate diet during the early, middle, and late fattening stages consecutively (10–14, 15–22, and 23–30 months of age, respectively). The rumen fluid and solid samples collected at each stage were subjected to sequencing analyses. The sequencing results were clustered and classified into operational taxonomic units (OTUs). Representative sequences and a raw counting table for each OTU were submitted to the Piphillin website. The predicted functions were revealed by the Kyoto Encyclopedia of Genes and Genomes database as the ratio of the total sequence. In the early stage, “Biosynthesis of secondary metabolites” was significantly higher in the fluid fraction than in the solid fraction. “Two-component system” in the middle stage was significantly lower and “Purine metabolism” in the late stage was significantly higher in the fluid fraction than those in the solid fraction. The fluid fraction was significantly correlated with acetic acid, propionic acid, and bacterial metabolism, such as “Biosynthesis of secondary metabolites” and “Sugar metabolism.” Moreover, the solid fraction was correlated with “Purine metabolism” and “Biosynthesis of secondary metabolism”. These results suggest that the rumen bacterial community in Japanese Black beef cattle adapts to changes in rumen conditions by altering their functions in response to a long-term high-grain diet. 相似文献
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TOSHISADA SUZUKI IZUMI USUI KAORI TOMITA-YOKOTANI SHINYA KONO HIROKAZU TSUBURA YOICHI MIKI KOJI HASEGAWA 《Weed Biology and Management》2001,1(4):226-230
The effects of acid extracts of tomato ( Lycopersicon esculentum Mill.) and carrot ( Daucus carota L.) juice wastes from the food industry on the growth of five species of crops and four weeds were examined. The acid extract of the tomato juice waste promoted the shoot and root growth of tomato, Chinese cabbage, corn, and radish, but not the growth of oat seedlings. The extract did not promote the shoot growth of weeds tested, and it inhibited the root growth of the weeds that included barnyardgrass ( Echinochloa oryzicola Ohwi), southern crabgrass ( Digitaria ciliaris Koel.) and Japanese barnyard millet ( Echinochloa utilis Ohwi). The carrot juice waste was also examined as another waste from the food industry. The effect of the acid extract of carrot juice waste showed significant promoting effects on the root growth of Chinese cabbage; however, the effects on other plants were lower than that of tomato juice waste. It also did not inhibit the growth of weeds. These results suggested that the acid extract from tomato juice waste is useful as plant-growth substances because they have a promoting effect on the shoot and root growth of crops, and an inhibitory effect on the root growth of some weeds. 相似文献
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采用固体分散技术制备黄连解毒固体分散体,对其进行处方筛选及正交试验优化工艺,以盐酸小檗碱溶出度为主要指标,从性状、粒度、含量、稳定性等方面评价其质量。结果表明,通过溶剂一熔融法制备黄连解毒散固体分散体最为适宜的条件是:载体和中药散剂的比例为1:3、熔融温度100℃、反应时间1h。制备的黄连解毒固体分散体性质稳定,盐酸小檗碱的平均含量为12.98mg/g,90min时溶出度均可达93%以上。 相似文献