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41.
食用茉莉花香味成分的GC/MS分析 总被引:6,自引:0,他引:6
采用水蒸气蒸馏-乙醚萃取法对云南引种食用茉莉花中芳香性成分进行了提取,并用气相色谱-质谱联机技术对其中化学成分进行分析鉴定.共鉴定出46种芳香性有机成分,占茉莉花挥发油提取物总含量的99.9005%.通过对食用茉莉花芳香性成分的分析,为茉莉花香精香料的开发提供了依据. 相似文献
42.
综合分析了当今档案软件现状及发展趋势,根据需求的分析确定了基于Client/Server体系结构的应用模型,建立了以数据库管理系统为核心的声像档案信息管理系统,并详细介绍了通用模块、文书与声像档案模块的开发. 相似文献
43.
Anish Dave 《Technical Communication Quarterly》2015,24(3):258-286
I explore the role of categories as rhetorical barriers in organizations responding to crisis (Veil, 2011). I analyze some problematic categories of the Department of Homeland Security (DHS) and the Federal Emergency Management Agency (FEMA) and the categories’ impact on the organizations’ response to Hurricane Katrina. My analysis shows that unintended and perverse consequences (Giddens, 1984, 1987) reversed the power of a key legitimated category (Orlikowski, 1995; Giddens, 1984) and exposed a set of reified categories (Giddens, 1984). 相似文献
44.
A high-speed train-track coupling dynamic model is used to investigate the dynamic behavior of a high-speed train operating on a curved track with failed fasteners. The model considers a high-speed train consisting of eight vehicles coupled with a ballasted track. The vehicle is modeled as a multi-body system, and the rail is modeled with a Timoshenko beam resting on the discrete sleepers. The vehicle model considers the effect of the end connections of the neighboring vehicles on the dynamic behavior. The track model takes into account the lateral, vertical, and torsional deformations of the rails and the effect of the discrete sleeper support on the coupling dynamics of the vehicles and the track. The sleepers are assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. The train model couples with the track model by using a Hertzian contact model for the wheel/rail normal force calculation, and the nonlinear creep theory by Shen et al. (1984) is used for wheel/rail tangent force calculation. In the analysis, a curved track of 7000-m radius with failed fasteners is selected, and the effects of train operational speed and the number of failed fasteners on the dynamic behaviors of the train and the track are investigated in detail. Furthermore, the wheel/rail forces and derailment coefficient and the wheelset loading reduction are analyzed when the high-speed train passes over the curved track with the different number of continuously failed fasteners at different operational speeds. Through the detailed numerical analysis, it is found that the high-speed train can operate normally on the curved track of 7000-m radius at the speeds of 200 km/h to 350 km/h. 相似文献
45.
高元明 《温州职业技术学院学报》2013,(2):58-61
概率布尔网络是布尔网络的拓展。布尔网络和概率布尔网络已经广泛应用于生物系统模拟中。运用马尔科夫链模拟概率布尔网络的动态行为及采用消除趋势波动分析(DFA)方法,分析概率布尔网络的长程相关性特性发现,概率布尔网络的动态行为具有长程相关性,大部分概率布尔网络能呈现1/f波动,且产生1/f波动的噪声值和范围比布尔网络的大。 相似文献
46.
目的:探讨复方丹参片早期干预对APP/PS1转基因小鼠学习记忆的影响及作用机制。方法:4月龄野生型小鼠和APP/PS1转基因小鼠分别灌胃给予溶剂或药物8周后,采用新物体识别实验和跳台实验评价复方丹参片对小鼠行为学表现的影响;应用ELISA检测小鼠海马β淀粉样蛋白(β-amyloid protein,Aβ)Aβ40、Aβ42的含量;采用Real time PCR和Western blot分别检测胰岛素分解酶(insulin degrading enzyme,IDE)/脑啡肽酶(neprilysin,NEP)m RNA和蛋白水平的变化。结果:新物体识别实验结果显示,复方丹参片720 mg·kg-1显著性增加APP/PS1转基因小鼠对新物体的识别指数。跳台实验结果显示,复方丹参片720、360 mg·kg-1显著性减少APP/PS1转基因小鼠学习次数,此外,复方丹参片720 mg·kg-1明显增加小鼠在平台的停留时间。ELISA结果显示,复方丹参片720、360 mg·kg-1显著性降低APP/PS1转基因小鼠海马Aβ40、Aβ42水平。Real-time PCR结果显示,复方丹参片720 mg·kg-1显著性上调APP/PS1转基因小鼠海马IDE和NEP m RNA的表达。Western blot结果显示,复方丹参片720 mg·kg-1显著性增加小鼠海马IDE蛋白表达。结论:复方丹参片可改善APP/PS1转基因小鼠学习记忆能力,可能与减少海马Aβ水平和增加IDE的表达有关。 相似文献
47.
ZHENG Bing-jie 《海外英语》2014,(22):284-287
The issue of bilingualism has been widely explored in the past decades,showing that there are multiple positive effects of"additive bilingualism".Such positive factors are closely linked with children’s cognitive development and intelligence.This paper gives a detailed review on how bilingualism plays a role in children’s divergent thinking ability.Fully taking advantage of such positive effects in language education should be a significant part for bilingual education and foreign language programs.Thus,this paper further discusses the educational implications of these theoretic findings,suggesting that an additive bilingual environment should be cultivated through multiple ways of curriculum and program planning. 相似文献
48.
杨洪春 《黄石理工学院学报(人文社科版)》2006,23(2):84-92
本文简单探讨了tcp/ip协议,并利用网络协议分析器对Ieternet网络中数据包实例进行了解析。 相似文献
49.
院(系)级党组织是教育和团结本单位广大师生员工的政治核心,在学校党组织结构中处于承上启下的关键位置。新修订的高校基层组织工作条例,首次把党政联席会议制度确立为院(系)的工作机制和决策方式。当前,有些高校在落实党政联席会议制度时,还存在着一些问题。因此,必须建立健全党政联席会议的议事决策机制,进一步健全和完善党政联席会议制度,保证院(系)级党组织的政治核心,保证监督作用的有效发挥。 相似文献
50.
This paper describes the sexual socialisation process of marginalised, drug-using heterosexual black men, focusing primarily on the sources and content of sexual information. Analysing qualitative interview data, we discovered that the men in our sample both learn about sex and become sexually active at an early age. They most often learn about sex from the media and least often learn about sex from family members. The content of sexual information varies in specifics, but overall tends to equate sex with pleasure, encourage sexual activity with multiple partners and emphasise using protection. Our goal is to use this data to better understand how sexual socialisation contributes to the prevalence of multiple sexual partners and high rates of HIV among heterosexual black men in order to inform future risk-reduction intervention programmes. 相似文献