柑桔属果皮精油的GC-MS分析 Ⅰ.广西容县沙田柚精油化学成分的研究

以气相色谱-质谱-计算机联用技术研究了广西容县柚皮精油的化学成分,从其总离子流色谱峰鉴定了36个化合物,其中部分倍半萜化合物(萨剔烯、艾里莫芬烷、异可拉酮、长叶蒎烯等)在该精油中为首次发现。     

不同生长期黄蒿挥发油化学成分分析

本文采用水蒸气蒸馏法从黄蒿中提取挥发油,分析不同生长期黄蒿挥发油的主要化学成分,用气相色谱-质谱联用法对其化学成分进行鉴定,归一法计算各组分的相对百分含量.从三个不同生长期黄蒿的挥发油中鉴定出25、28、24种成分,相同成分17种,其中开花期黄蒿挥发油种类和含量较多.共有成分主要是篙属酮(Artemisia ketone)、石竹烯(Caryophyllene)、4(14),11-桉叶二烯(Eudesma-4(14),11-diene)、金合欢烯(Farnesene)、甜没药萜醇(Bisabolol)等.     

超临界CO2萃取黔产干姜挥发油的化学成分及抑菌活性研究

利用超临界CO2萃取法提取黔产干姜挥发油,通过气相色谱一质谱联用(GC-MS)技术对其化学成分进行分析并采用归一化法测定其相对含量;采用纸片法研究干姜挥发油对金黄色葡萄球菌和铜绿假单胞菌的抑菌活性,并用试管法测定了最低抑菌浓度.从超临界提取的黔产干姜挥发油中共分离鉴定出41个化合物,主要成分为α-姜烯(45.52％),β-倍半水芹烯(15.55％),α-法呢烯(9.79％),β-甜没药烯(6.21％),A-姜黄烯(5.01％),姜酮(3.13％);干姜挥发油对金黄色葡萄球菌和铜绿假单胞菌均有抑制作用,经测定最低抑菌浓度均为250μL/L.     

毕拨挥发油化学成分的固相微萃取研究

采用固相微萃取/气相色谱／质谱法分析毕拨挥发油化学成分,在毕拨挥发油化学成分中,共分离出115个成分,鉴定出其中的81个成分,已鉴定成分占总挥发油成分峰面积的97．83％;主要为萜烯类及其含氧衍生物等化合物,含量较高的成分是α-律草烯（4．44％）、α-姜黄烯（4．94％）、大根香叶烯-d（5．67％）、十五烷（12．30％）、β-没药烯（6．20％）、十七（碳）-8-烯（6．66％）、8-十七（碳）烯（9．29％）、十七烷（9．07％）等化合物。     

山东野生百里香挥发油化学成分的GC-MS研究

采用水蒸气蒸馏法提取百里香挥发油;利用气相色谱-质谱联用技术(GC-MS)对山东野生百里香挥发油化学成分进行分离鉴定,共分离鉴定出了30种化合物,占挥发油总量的98.92%,主要成分为百里香酚(15.64%),香芹酚(13.27%),冰片(12.86%),莰烯(8.07%),桉树脑(6.22%),α-蒎烯(5.35%)等.本实验方法可靠,重现性好,易于操作.     

六个花椒栽培种挥发油组分的特征性差异及生物学意义（英文）

从花椒人工引种栽培出发,通过气相色谱法-质谱法联用法(GC-MS)分析了6个不同花椒栽培种的挥发油组分,据此进行了聚类分析,研究结果如下。(1)占挥发油99.07%~99.78%的71种化合物得以鉴定,其中29种为6个栽培种共有。(2)聚类分析将6个品种分为3类:Dahongpao A~C(Ⅱ~Ⅳ)与Shizitou(Ⅵ)聚为一类,因为有6个主化合物相同,为β-月桂烯、(E)/(Z)-β-罗勒烯、枞油烯、桉树脑和4-羟基松油醇,占挥发油的53.46%~70.42%;Qin’an(Ⅰ)单独一类,因为其α-柠檬烯占挥发油的60.53%;Meifengjiao(Ⅴ)也单独成类,其主成分和其他品种均不同,含21.17%β-芳樟醇和20.80%乙酸芳樟酯,而其他品种的这些成分却低于3%。(3)Dahongpao B/C、Qin’an和Meifengjiao分别具有良好的抗肿瘤、抗真菌、抗细菌及杀虫潜力。     

黄瑞香干燥叶片挥发油的GC-MS分析及抑菌活性研究

采用水蒸气蒸馏法对黄瑞香干燥叶片挥发油进行提取,运用毛细管气相色谱-质谱联用法结合计算机检索对黄瑞香干燥叶片挥发油进行成分分析和鉴定,经毛细管色谱分离出68个峰,并确认了这68种化合物,所鉴定化合物的含量占全油的99.51%.用气相色谱面积归一化法测定了各组分的相对百分含量.其化学成分主要为:3-己烯-1-醇、顺式-α,α,5-三甲基-5-四氢呋喃-2甲醇、天然壬醛、十六烷、二噻吩乙酸,3-三癸酯、柏木脑、2-乙氧基丁烷、β-紫罗酮、1-乙氧基丙烷、苯乙醛、6,10-二甲基-5,9-十一双烯-2-酮、十五烷、(2R,3R)-(-)2,3-丁二醇、杜松烯、六氢合金欢丙酮、(E)-呋喃基芳樟醇氧化物,以上十六种化合物占其挥发油总量的66.78%.利用滤纸片扩散法研究山胡椒挥发油对7种常见食源性污染菌的抑菌作用,并探讨加热处理对水蒸汽蒸馏法所得挥发油抑菌活性的影响.实验表明,所得挥发油对6种污染菌都有抑制作用,而且加热处理对水蒸汽蒸馏法所得黄瑞香干燥叶片挥发油的抑菌效果无明显影响.     

美花红千层挥发油的化学成分分析

应用水蒸气蒸馏法从美花红千层叶提取挥发油,利用气相色谱-质谱联用技术(GC-MS)分离鉴定芳香成分,采用GC峰面积归一法确定其相对含量,鉴定了其中的21种化合物,占色谱总馏出峰面积的94.77%,其主要成分是1,8-桉叶素(43.36%)、α-蒎烯(33.18%)、α-松油醇(7.37%)、柠檬烯(3.57%)。     

潮州柑果皮挥发油的组分分析及其抑菌性和抗氧化性的研究

利用水蒸汽蒸馏法提取潮州柑(Citrus reticulata Blanco‘Jiao gan’)果皮中的挥发油,并用气相色谱-质谱联用法对其化学成分进行分析和鉴定,并利用比重瓶法等测定挥发油的相对密度等理化性质;以金黄色葡萄球菌、大肠杆菌等为受试菌株,观察潮州柑果皮挥发油对各菌的体外抑制作用;以清除DPPH自由基的能力考察挥发油的抗氧化性.结果表明,潮州柑果皮精油共鉴定出66种化学成分,其含量占挥发油总量的98.89%,主要为:D-柠檬烯(93.75%)、β-月桂烯(2.46%)、β-芳樟醇(1.55%)、α-蒎烯(0.57%)、乙酸乙酯(0.34%)、3-蒈烯(0.14%),α-水芹烯(0.05%),4,5-二甲基-2,6-辛二烯(0.03%).理化性质结果表明:潮州柑果皮挥发油的相对密度为0.83,折光率为1.47,酸价为7.29,过氧化值为8.33 meq/kg,含皂量0.07%.抑菌试验结果表明:潮州柑果皮挥发油可抑制金黄色葡萄球菌、藤黄微球菌、枯草芽孢杆菌、大肠杆菌等细菌的生长.抗氧化性分析表明:潮州柑果皮挥发油可有效清除DPPH自由基,其IC50值为50.16μg/mL.上述实验结果表明,潮州柑果皮精油可作为一种食品防腐剂或抗氧化剂应用.     

肾茶叶挥发油化学成分分析

用水蒸气蒸馏法、溶剂萃取法从新鲜肾茶叶中提取挥发油,用气相色谱-质谱联用技术对挥发油的化学成分进行了分析,用气相色谱面积归一化法测定了各个成分的相对百分含量.共分离出82个峰,鉴定出82个化学成分.其中主要成分柏木醇(53.64%)、斯巴醇(4.13%)、1-辛烯-3-醇(3.92%)、α-柏木烯(3.47%)、蓝桉醇(3.24%)和β-柏木烯(2.51%).     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.