植物乳杆菌对苜蓿青贮发酵品质和细菌菌群的影响

为了探究植物乳杆菌(Lactobacillus plantarum)作为添加剂对苜蓿青贮发酵品质与细菌菌群的影响,以新鲜苜蓿为原料,分别添加植物乳杆菌YX(LPI)或ZZU A341(LPA),以无添加剂为对照组.青贮60 d后取样分析发酵品质,并利用高通量测序技术分析细菌菌群变化情况.结果表明:青贮60 d后,与对照...     

添加剂对甘蔗梢叶青贮营养价值的影响

【目的】考察不同添加剂对甘蔗梢叶青贮营养价值的影响,为甘蔗梢叶高饲料化利用提供参考依据。【方法】采用单因素实验法考察尿素、糖蜜、乳酸菌液的添加和三者混合添加对甘蔗梢叶青贮营养价值的影响。【结果】不同的添加剂均能改善甘蔗梢叶青贮的营养品质。当尿素添加量为0.5%(W/W)时最佳,粗蛋白和粗脂肪含量分别提高34.68%和61.27%,半纤维素和中性洗涤纤维(NDF)分别降低10.67%和6.23%,差异极显著(P0.01);当糖蜜添加量为15%(W/W)时最佳,粗蛋白和粗脂肪含量分别提高20.42%和36.42%,纤维素、NDF和酸性洗涤纤维(ADF)分别降低54.04%,28.30%和45.72%,差异极显著(P0.01);单独添加乳酸菌对青贮影响不明显,差异不显著(P0.05);同时添加0.5%(W/W)尿素、15%(W/W)糖蜜和5%(W/W)乳酸菌液青贮效果最佳,粗蛋白和粗脂肪含量分别提高85.92%和69.36%,纤维素、NDF和ADF分别降低38.94%,17.92和33.44%,差异极显著(P0.01)。【结论】在甘蔗梢叶青贮时,同时添加尿素、糖蜜和乳酸菌,能有效降低其粗纤维含量,提高消化利用率。     

添加尿素对青贮玉米秸秆品质的影响

为了探讨添加尿素对青贮玉米饲料品质的影响,试验用不同剂量的尿素作为添加剂对原料进行青贮调制,并对开封后的青贮饲料进行了感官评定和实验室评定。结果表明:添加尿素的青贮玉米秸秆,其感官评定等于或优于对照组;实验室评定中青贮饲料的各组间的pH值差异不显著;各组间粗纤维的含量无显著变化;各组间的粗蛋白含量差异显著,特别是使用5g/kg的尿素作用显著优于其它各组。     

燕麦青贮研究进展

燕麦既可调制干草也可制作青贮,但在西北、西南、华北、东北等高寒农牧区有些地区由于制作干草时处于阴雨天气不宜调制干草,只能进行青贮.燕麦青贮在动物生产中作为一种优良的青贮饲料具有适口性好、营养价值高、环境适应范围广等特点.就燕麦青贮时期、添加剂青贮、混合青贮、青贮饲喂效果进行了综述,促进燕麦青贮的利用和发展.     

玉米秸青贮与黄贮及苜蓿干草的体外动态消化研究

采用产气量法测定了玉米秸青贮、玉米秸黄贮和苜蓿干草的瘤胃微生物体外动态消化参数。将3种饲料样品及其分离出的相应的中性洗涤纤维（NDF）同时进行72h体外发酵，并测定不同时间点的产气量，中性洗涤可溶物（NDS）的产气量可由饲料样品与其相应的DNF的产气量之间的差值计算得到。结果表明，3种饲料的72h累积产气量没有显著性差异，但3种饲料相应的NDF和NDS部分对产气量的贡献不同（P＜0.05）。其产气量曲线变化趋势受饲料中NDS和NDF的含量及消化率的影响。3种饲料经72h发酵后对瘤胃液的pH值没有显著影响，但对发酵终产物挥发性脂肪酸（VFA）的摩尔百分比有影响（P＜0.05）。     

不同添加方式对添加剂强化吸收的影响

为研究界面活性添加剂对吸收过程的强化作用,采用分子中含5~10个碳原子的多种醇类物质作为添加剂进行静态池吸收实验.采用传统的液相添加、两种添加剂的液相混合添加、吸收器中气相添加、蒸发器中气相添加及气、液相同时添加等添加方式,测试了多种添加剂对溴化锂溶液吸收水蒸气的影响.实验结果表明,添加剂在不同添加方式下均能起到一定的强化吸收作用.     

不同生育期苜蓿叶蛋白的营养价值

利用直接加热法提取了不同生育期的苜蓿叶蛋白,并对其进行了营养价值评价。结果显示,苜蓿叶蛋白较适合少年的需要,其中初花期叶蛋白的营养价值最高。     

静电场对苜蓿幼苗期酶活性的影响

为了研究静电对紫花苜蓿(Medicago sativa Leguminosae)抗旱性的影响，寻找出提高紫花苜蓿幼苗抗旱性的最佳电场条件。在静电场不同电场强度下处置紫花苜蓿种子10min后，室温下培养9d，再测定幼苗的丙二醛(MDA)的含量和过氧化物酶(POD)、超氧化物酶(SOD)的活性。实验所用电极电压波形为50Hz半波整流，电场强度共11个，其中1个未经电场处理作为对照组。结果表明，在11个电场处理的材料中，有6个MDA水平低于对照，1个与对照相同，其余4个高于对照，变化幅度为22．8％～34．8％。SOD酶和POD酶的活性普遍降低，降低幅度分别为7．7％～57．7％和0．5％～59．4％。静电场处理可以提高紫花苜蓿幼苗的抗旱性。     

蜗牛壳里的御宅族

“宅文化”、似乎成了席卷整个亚洲的风潮，尤其是在经济危机的影响下，越来越多的青年人选择御宅生存，如同背着全部家当的蜗牛。     

各种添加剂对低温陶瓷结合剂性能的影响

实验主要研究6种添加剂对陶瓷结合剂性能影响。实验证明,随着α-Al2O3加入量的增多,结合剂的熔点逐渐升高,在加入量为15%时流动度最好;CuO、Cr2O3和Zn对结合剂熔点有明显的提高作用;Sn和Cu可以降低结合剂的熔点;加入8%Cr2O3或加入6%Sn时其流动度值最佳。     

A study on the effect of the bacterial inoculant on corn silage quality,digestibility and performance in dairy cattle

Effect of the bacterial inoculant Sil-All (short for ‘ SA‘ ) on corn silage quality, digestibility and performance in dairy cattle was studied. SA treated silage resulted in the higher level of retained protein and slightly higher level of residual sugars in that treatment, the better digestibility of the neutral detergent fibre (NDF) and the acid detergent fibre (ADF), the lower pH and evolution of ammonia compared to the control; The fall in pH was most rapid in the SA treated silage in the first 4 days of ensilage, when it matters most for the conservation of protein, compared with the control silage and this was linked more to both lactic and total acids. Both volatile fatty acid (VFA) and lactate content increased with ensiling time, increase degree reached up near 100%; Lactate content in treatment silage was higher than that in the control, and this difference was all maintained at the level of approximately 7% - 13% almost in all cases, at length, up 16% in the case of day 15; pH value decreased with ensiling time. Moreover, pH value in most of treatment were lower than that in the control ; The digestibility of both dry matter (DM) and crude protein (CP) was appreciably improved by the use of inoculant SA. Also, in relation to reductions, of NDF and ADF were noted. An increase in milk yield of the order of 0.9kg per head per day in favour of SA was observed. Alternatively, with an average daily feed intake of 20kg, this indicates with 1 ton of corn silage milk yield could be increased by 46.5kg.     

Diet control on carbon isotopic composition of land snail shell carbonate

Carbon isotope compositions for both the carbonate shells and soft bodies (organic tissue) of living land snails collected mostly from the Loess Plateau, China have been measured. The result shows that δ 13C values range from -13.1‰ to -4.3‰ for the aragonite shell samples and from -26.8‰ to -18.0‰ for the soft body samples. Although the shells are enriched in 13C relative to the bodies averagely by 14.2(±0.8)‰, the shell δ 13Ca values are closely correlated to the body δ 13Corg values, expressed as δ 13Ca = 1.021 δ 13Corg 14.38 (R = 0.965; N = 31). This relationship indicates that δ 13Ca is primarily a function of the isotopic composition of the snail diets since previous studies have proved that the snail body is the same as their food in carbon isotope composition. In other words, carbon isotope compo-sition of the carbonate shell can be used as a proxy to estimate the dietary 13C abundance of the land snails. The data also support that the 13C enrichment of the carbonate shells results mainly from the equilibrium fractionations between the metabolic CO2, HCO3-in the hemolymph and shell aragonite, and partially from kinetic fractionations when snail shells form during their activity.     

民间节令食品营养意义初探——荠莱习俗

通过对民间荠莱习俗的初步分析，试图从节令与人体营养的关系角度，对节令食品是否具有合理性、科学性作初步探讨。     

菜芙蓉多糖对秀丽隐杆线虫抗氧化作用的研究

为进一步研究菜芙蓉多糖（AMP）的体内生物学作用,系统探究其抗氧化机理,以秀丽隐杆线虫(Caenorhabditis elegans)为模型,分析了正常生长条件及氧化应激条件下,空白对照组(0 mg/mL)、低剂量组(25 mg/mL)、中剂量组(50 mg/mL)、高剂量组(100 mg/mL)AMP对线虫生理指标、生化指标及细胞凋亡的影响。结果表明,正常生长条件下AMP可延长线虫寿命、降低生殖能力、提高运动能力,降低线虫体内MDA和ROS含量、提高SOD,CAT和GSH-Px 的酶活性。在200 μmol/L胡桃醌氧化应激条件下,AMP可提高线虫存活率,并能有效清除体内ROS、降低MDA含量,提高线虫体内SOD,CAT和GSH-Px 的酶活性,抑制细胞凋亡。AMP可通过提高线虫体内抗氧化防御系统酶活性及清除自由基提高氧化应激抵抗力,因此AMP有潜力成为一种新的抗氧化天然多糖。     

不同添加剂对石膏模型性能的影响

研究了分别以聚乙烯醇 (PVA )、聚乙烯醇缩甲醛 (PVF)和甲基纤维素 (MC)为添加剂对石膏模型性能的影响。结果表明三种添加剂的加入均可使石膏模型的强度增大 ,在聚乙烯醇和甲基纤维素的加入量为 0 .3%时 ,石膏模型的抗折强度最大 ;添加剂使石膏的凝结时间略有延长 ,添加剂的加入使石膏模型的吸浆厚度略有减小 ;添加剂的加入均能提高石膏模型的耐碱蚀能力。     

掺外加剂的橡胶沥青SMA混合料设计方法

为了研究橡胶沥青SMA混合料的配合比设计和路用性能,在普通SMA配合比设计方法的基础上,选择3种橡胶粉、1种基质沥青和4个间断级配,对橡胶沥青混合料配合比设计过程进行了详细的介绍;利用车辙试验和疲劳试验,分析了不同油石比、外加剂(如SBS、高模量耐久剂)等对混合料高温稳定性能和抗疲劳性能的影响。结果表明:与普通SMA混合料相比,橡胶沥青SMA混合料具有较小的矿粉用量和较大的目标空隙率;随着油石比的增大,橡胶沥青SMA混合料的高温稳定性能逐渐降低,抗疲劳性能则不断提高;车辙试验结果和疲劳试验结果呈现一致的规律,即油石比较大时,高模量耐久剂对混合料路用性能的提高作用更为明显。     

Variability of snail growing season at the Chinese Loess Plateau during the last 75 ka

Knowledge of seasonal climate change is one of the key issues facing Quaternary paleoclimatic studies and estimating seasonal climate change is difficult,especially changes such as seasonal length on glacial-interglacial timescales.The stable isotope composition from seasonal land snail shells provides the potential to reveal seasonal climatic features.Two modern land snail species,cold-aridiphilous Pupilla aeoli and thermo-humidiphilous Punctum orphana,were collected from different climatic zones in 18 localities across the Chinese Loess Plateau,spanning 11 degrees of longitude and covering a range of 1000 km2.The duration of the snail growing season(temperature ≥10℃) was shorter(202 ± 6 d) in the eastern Loess Plateau compared with in the western Loess Plateau(162 ±7 d).The δ13C of P.aeoli shells was ?9.1‰ to ?4.7‰ and ?5.0‰ to 0.3‰ for δ18O.For P.orphana,the δ13C ranged from ?9.1‰ to ?1.9‰ and ?8.9‰ to ?2.9‰ for δ18O.Both the δ13C and δ18O differences between the two snail species were reduced from the east to the western Loess Plateau(2.8‰ to 0.2 ± 1.1‰ for δ13C and 4.7‰ to 2.9 ± 1.3‰ for δ18O).These isotopic differences roughly reflect the difference in the growing season lengths between the east and west Loess Plateau indicating that the duration of the snail growing season shortens by 15 d or 19 d if the difference decreases by 1‰ in δ13C or δ18O,respectively.Thus,the difference in δ13C and δ18O between both snail species can be used to reveal the length of the snail growing season in the past.Based on our investigation,the length of the snail growing seasons from the Xifeng region during the last 75 ka was reconstructed.During the mid-Holocene(8-3 ka),the mean isotopic difference from both snail species reached maximum values of 2.6 ± 0.7‰ and 2.1 ± 1.4‰ for δ13C and δ18O,respectively.This was followed by MIS 3 that ranged from 2.5 ± 0.4‰ for δ13C and 1.6 ± 0.8‰ for δ18O.The Last Glacial Maximum changed by only 0.2‰ and 0.4‰ for δ13C and δ18O,respectively.Therefore,we estimate that the duration of the snail growing seasons to be ～200 ± 10 d during the mid-Holocene,190 ± 6 d in MIS 3 and 160 ± 3 d during the last glacial period.     

不同物流条件对荔枝品质的影响(英文)

分析了鲜荔枝在物流与运输全过程(如采收→转运→分级→前处理(预冷和杀菌)→包装→运输→销售)中的品质变化,通过对比不同物流运输条件下荔枝果皮褐变指数和果皮花色素苷含量的变化速率,观察对荔枝的品质影响,结果表明:低温环境(3.5～5.5℃)和预冷杀菌等预处理在荔枝的整个物流过程中都起到了积极的作用,大大减缓果实的褐变进程;为延长其货架期,荔枝销售也应当在低温环境之下,通常在5～13℃为宜.