不同喷灌定额下垄作沟播油葵根系生长及分布特征

垄作沟播喷灌技术是集垄作沟播与喷灌技术为一体的节水栽培技术.以不同灌水定额各设4个处理(灌水定额分别为24 mm、30 mm、36 mm、42 mm,灌水5次),以常规覆膜喷灌为对照(灌水定额42 mm,灌水5次).通过测定不同灌水处理下垄作沟播油葵根系生长及分布特征等指标,分析了不同灌水处理对油葵根系纵向、横向生长及...     

车辆换挡系统调压阀优化设计与试验

针对车辆换挡充油过程中离合器充油压力曲线的实际值与理想值之间存在偏差的问题,建立了包含供油单元、电磁换向阀、调压阀和离合器的换挡系统仿真模型,采用AMESim对充油过程进行仿真分析。以充油压力为优化目标,应用误差积分准则确定优化函数,通过Pareto图得到调压阀中影响充油压力的关键参数为阀口开度、弹簧预紧力和阻尼孔直径。分别采用二次拉格朗日非线性规划算法(Non-linear programming by quadratic Lagrangian,NLPQL)和遗传算法(Genetic algorithms,GA)对上述参数进行优化。对比优化后的仿真充油曲线与理想充油曲线,可知遗传算法为最优算法,并确定了调压阀的最优结构参数。根据控制变量法设计试验方案,结果表明,采用遗传算法优化后,换挡系统的稳定性在一定程度上得到提高,其充油过程更加符合理想充油过程,换挡品质得到改善。     

土壤含水量对茴香植株生长及精油含量和组分的影响

 采用控制浇水量的方法设计土壤(相对含水量为低44.46%±1.22%~52.84%±2.34%）、中（59.75%±3.11%~77.85%±3.47%）、高（75.24%±3.24%~99.27%±5.67%）3个范围,研究土壤含水量对茴香生长与精油含量及其组分的影响。结果表明,随着土壤含水量的升高,茴香株高、植株节数、根干质量、地上部干质量、全株干质量、全碳含量、单株精油产量和叶绿素a/叶绿素b均随之升高,而根冠比、全氮含量、蛋白氮含量、叶绿素a含量、叶绿素b含量和类胡萝卜素含量均随之下降;中土壤含水量的植株花序数、精油含量和可溶性糖含量较高,低和高土壤含水量的则较低;不同土壤含水量处理茴香植株,其精油共鉴定出22种成分,除α-蒎烯、香桧烯、β-蒎烯、γ-萜品烯、萜品油烯、肉豆蔻醚6种成分相对含量差异不显著外,其余16种成分相对含量均表现出显著或极显著差异;随着土壤含水量的增大,精油的第一主要成分反式—茴香脑含量呈升高趋势,低、中、高3个含水量处理的含量依次为41.34%、53.87%和62.97%,第二主要成分柠檬烯含量与反式—茴香脑含量变化相反,其3个含水量处理依次为44.77%、34.77%和22.16%。因此,低土壤含水量处理相对有利于茴香柠檬烯的积累,而高土壤含水量处理相对有利于反式-茴香脑的积累。     

迷迭香精油对几种植物病原菌的抑菌活性研究

采用生长速率法和抑菌圈法测定了迷迭香精油对甜瓜蔓枯病菌、西瓜炭疽病菌、甜瓜灰霉病菌、甜瓜枯萎病菌、梨树腐烂病菌、柑橘黑腐病菌、油菜菌核病菌、蚕豆轮纹病菌和桃细菌性穿孔病菌的抑菌活性.结果表明:迷迭香精油对8种病原真菌都具有很好的抑菌活性,其EC50分别为843.9914、1 084.2372、483.9457、1 735.5866、1 011.7869、901.2150、356.8803、1 197.3657 μL/L;对桃细菌性穿孔病菌也具有一定的抑菌活性,浓度为100 mL/L时,抑菌圈直径为1.00 cm,最低抑菌浓度为1 000 μL/L.     

大果沙棘籽和油的理化成分研究

本文对采于新疆青河的大果沙棘籽进行了理化指标的分析研究。结果表明：大果沙棘籽在粗脂肪、粗蛋白含量上优于中国沙棘,在脂肪酸组成、维生素E含量上与中国沙棘无明显区别。该结果为大果沙棘籽的进一步开发利用奠定了基础。     

Fatty Acid and Non-Fatty Acid Components of the Seed Oil of Celastrus paniculatus willd.

The yield and chemical composition of the seed oil of Celastrus paniculatus were determined by solvent extraction and gas chromatography-mass spectrometry. The yield of crude fatty oil was found to be 45.5% in the mature seeds on dry weight basis. Fourteen compounds, constituting 97.57% of the oil, were identified. The oil was rich in unsaturated fatty acids (70.11%) followed by saturated fatty acids (25.2%). Oleic acid (54.42%), palmitic acid (20.0%), linoleic acid (15.51%), and stearic acid (4.18%) were the main fatty acids in the oil together with four other minor fatty acids. The current study identifies the novel compounds not previously reported in C. paniculatus oil, including 1,4-benzenediol (0.46%), cinnamic acid (0.15%), 2,6-di-tert-butyl-p-benzoquinone (0.03%), butylated hydroxytoluene (0.4%), and eudalene (0.16).     

微波对毛酸浆籽油提取效率的影响及其脂肪酸分析

以毛酸浆种子为原料,研究索氏微波提取法对毛酸浆籽油提取效率的影响,并以甲酯化脂肪酸为标准品,采用气相色谱法对毛酸浆籽油脂肪酸成分进行分析,通过与标准品比对出峰时间确定试样脂肪酸成分,使用面积归一法确定试样中各脂肪酸含量。结果表明,与普通热风干燥相比,微波干燥法能够提高毛酸浆籽油的提取效率;利用气相色谱法对毛酸浆籽油进行脂肪酸分析,共检测出8种脂肪酸,分别为:肉豆蔻酸1.3%,棕榈酸10.3%,硬脂酸5.3%,油酸14.3%,亚油酸62.7%,亚麻酸4.0%,花生酸1.1%,二十二烷酸1.0%。其中不饱和脂肪酸相对含量占81.0%,说明毛酸浆籽油具有较高的营养价值,开发前景广阔。     

甜橙精油分子蒸馏组分的成分分析及其抗菌活性研究

应用分子蒸馏技术加工冷压甜橙精油,分离得到轻相与重相两个组分,采用气相色谱-质谱联用技术(GC-MS)分析其化学成分,鉴定出甜橙精油轻相组分中含22种化合物,重相组分中含40种化合物。抑菌试验结果表明,甜橙精油轻相和重相组分对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和酵母菌均具有较好的抑菌效果,最低抑菌浓度(MIC)范围为0.78~3.125μL/m L。抑菌活性受不同p H和温度条件的影响,酸性环境下轻相组分的抑菌效果较好,碱性环境下重相组分的抑菌活性更强。在高温处理下,轻相组分对细菌的抑菌效果具有较好的热稳定性,重相组分的抑菌效果有所减弱。     

Intra‐household constraints on educational attainment in rural households in Papua New Guinea

This paper examines intra‐household and socio‐cultural factors leading to differential outcomes in educational attainment by gender and birth order amongst smallholder oil palm households in Papua New Guinea. Not all children share equitably in the household resources allocated to education: females have lower average education levels than males, and high birth order children have higher education attainment than lower birth order siblings, indicating preferential parental investment in sons and early born children. The findings demonstrate that despite households having regular access to relatively high incomes from oil palm and residing in close proximity to schools, primary school net enrolment rates remain significantly lower than those for East Asia and the Pacific region, and the millennium development goal of universal primary education has not been met. This finding is likely to be the result of a combination of intra‐household factors including gender power imbalances, low parental education levels, the agency of youth in educational decision‐making and the weakening attraction of education as a means of improving income‐earning potential.     

茉莉花香气成分及其加工应用研究进展

笔者阐述了茉莉花香气成分的释放机理,分析了影响茉莉花香气成分的因素,指出茉莉花香气成分的释放主要是酶促反应的进行,是由花香前体物质在温度、水分、氧气等作用下经生物酶水解释放出来,认为品种、花的开放程度、产地、环境因子、提取方法都对茉莉花香气成分的组成和含量具有不同程度的影响,其中以花的开放程度、环境因子和提取方法最为明显。文章还对茉莉花在食品、茶叶、香烟及其他方面的应用做了概述,最后对茉莉花的理论研究以及开发新产品方面做了展望。