Chemistry of molecular growth processes in flames

Chemical mechanisms of pyrolysis, growth, and oxidation processes in flames have traditionally been inferred from spatial profile measurements of species concentrations. Experimental investigations now include the detection of numerous minor species such as reactive radicals and intermediate hydrocarbons. In assessing a proposed mechanism important new constraints can be established when the detailed species profile data are combined with velocity and temperature measurements and analyzed to determine production and destruction rates for specific molecules. Recent results on hydrocarbon diffusion flames provide new information on the interplay between chemical and transport processes. These measurements have led to direct tests of proposed routes for the formation of aromatic hydrocarbons and the first, small soot particles. The inception chemistry of hydrocarbon growth reactions and initial particle formation is thought to control soot formation, flame radiation and energy transfer, and pollutant emission in combustion environments.     

肌内磷脂在腌腊肉制品风味形成中的作用机制研究进展

肌内磷脂是腌腊肉制品风味形成的重要前体。腌制过程中,肌内磷脂主要发生了水解、氧化,氧化产物还可以通过美拉德反应与其他化合物进一步作用形成风味物质。本文综合论述了肌内磷脂在腌腊肉制品加工过程中所发生的变化及变化机制,讨论了这些变化在腌腊肉制品风味形成中的作用。     

CH3·与CO反应机理的理论研究

采用密度泛函B3LYP/6-311G**和QC ISD(T)/6-311G**方法计算研究了CH3.与CO反应机理,全参数优化了反应势能面上各驻点的几何构型,用内禀反应坐标(IRC)计算和频率分析方法,对过渡态进行了验证。研究结果表明:CO对CH3.自由基有稳定化作用。该反应的研究将为烃类的燃烧和大气环境的保护提供理论依据。     

巴菲蛤壳脂溶性成分的气相色谱-质谱联用分析

[目的]为寻找巴菲蛤壳脂溶性成分的新用途提供理论支持。[方法]以氯仿为溶剂回流提取巴菲蛤壳中的脂溶性成分,利用气相色谱-质谱联用仪对提得物质进行分离和鉴定。采用色谱峰面积归一化法确定脂肪酸各组成成分的相对含量。[结果]从巴菲蛤壳的脂溶性成分中分离鉴定出了44种成分,包括5种羧酸类化合物,占总量的16.44%,其中含量最高的是戊酸(8.43%)和4-氧基苯甲酸(3.59%);28种烃类化合物,占总量的40.87%,其中含量最高的是稠环芳烃萘烷(8.43%)、脂肪烃二叔十二烷基二十一烷(3.53%)、环烃环己烷(3.46%)和烯烃5-二十烯(0.45%);还有4种含溴化合物、2种硅氧烷类化合物、2种酮类化合物、2种含硫化合物和1种含硼化合物。[结论]烃类化合物可确定为巴菲蛤壳脂溶性成分中的主要成分。     

牛心朴子挥发油成分分析

采用气相色谱—质谱联用技术对牛心朴子的挥发油成分进行了研究 ,分离鉴定出 4 5种化合物 ,检出成分占挥发油总质量的 87.80 %。其中主要成分为烷烃 (33.5 9% ) ,不饱和脂肪酸 (19.4 7% ) ,酯 (18.5 5 % )和烯烃(9.6 8% ) ,9,12 -十八碳二烯酸相对含量最高 ,为 18.6 5 %。     

抽穗期小麦抗赤霉病与酚类物质的关系初探

研究了不同抗赤霉病小麦品种抽穗期穗部的总酚含量和初花期穗部多酚氧化酶活性与小麦抗赤霉病的关系。结果表明：总酚含量以及多酚氧化酶的活性在不同品种间达极显著差异水平,经接种材料的酶活性普遍显著高于未接种的。总酚含量、酶活性与相对病指二元回归结果表明：接种后的达显著水平,没有接种的没达到显著水平;偏相关系数是总酚含量达负的显著水平,多酚氧化酶活性为正,但没达显著水平。总酚含量与多酚氧化酶是共同作用于赤霉菌的。     

2种茼蒿素类似物对菜粉蝶生物活性研究

研究了2种茼蒿素类似物对菜粉蝶的生物活性。结果表明,12号和20号化合物对菜粉蝶4龄幼虫24h的选择性AFC50分别为398.88mg.L^-1T 280.54mg.L^-1,能明显降低菜粉蝶幼虫体重、蛹重和成虫的羽化率。     

青花椒根际土壤化感物质成分分析

用气质联用仪分析了青花椒根际区不同深度土壤水浸液中化感物质的成分。检测鉴定出表层土壤含有23个组分的化学物质,而深层土壤中含有29个化学组分。在不同深度根际土壤中主要含有烷烃类、醇类、酯类、苯类、酚类及胺等有机化合物,其中包含有很多曾经被报道过的化感物质。结果表明,在青花椒根际土壤环境中确实存在化感物质。     

固相微萃取分析发酵肉制品中的挥发性风味组分

为开发新型肉制品,运用SPME-GC-MS对传统侗族发酵肉制品中的挥发性风味组分进行了分析.结果表明,在鉴定出的48种风味物质中,酯、醛、醇、烷烃分别为13,11,6,5种,其他杂环化合物13种.主体风味成分是己酸乙酯、苯乙醇、辛酸和辛酸乙酯.     

Detection of C3 in the Circumstellar Shell of IRC+10216

Vibration-rotation lines of C(3) have been identified in the circumstellar spectrum of the obscured carbon star IRC+10216. This molecule is of interest in both the chemistry of flames, where it may be involved in the formation of soot, and in astrophysics, where it is a potential building block for carbonaceous grains. This high-resolution infrared detection of the pure carbon chain molecule C(3) allows the estimation of the equilibrium C-C bond length, 1.297 angstroms. Possible astrophysical formation and destruction mechanisms for C(3) are reviewed, including the relationship between C(3) and carbon clusters.     

A model study of fecapentaenes: mutagens of bacterial origin with alkylating properties

Fecapentaene-14 and -12 are directly acting mutagens that do not require metabolic activation. Their unusual structure suggests a possible mechanism of action. A carbocation that is formed by the addition of an electrophilic species (such as a proton) to the enol ether is most probably the reactive species. A series of model enol ethers with conjugated systems of various lengths was prepared, and a correlation between mutagenicity and increasing reactivity of derived carbocations was found. The glycerol moiety does not play a crucial role in the overall reactivity of the fecapentaenes.     

Catalytic production of high-grade fuel (gasoline) from biomass compounds by shape-selective catalysis

Shape-selective hydrocarbon catalysis, such as the conversion capability of zealite catalysts of the ZSM-5 type to produce high-grade gasoline from methanol, can be extended to produce a similar gasoline or aromatics from plant extracts. Examples are rubber latex, corn oil, and peanut oil. Novel mechanisms for shape-selective reaction sequences are demonstrated.     

有机-无机复合污染对扇贝积累石油烃的影响

[目的]研究有机-无机复合污染对扇贝积累石油烃的影响。[方法]在实验室模拟条件下研究石油烃与Cu、Pb复合污染对栉孔扇贝积累石油烃的影响。[结果]单一石油烃污染条件下,石油烃在栉孔扇贝体内的积累量随暴露时间的延长及石油烃浓度的增大都有明显增大趋势;复合污染条件下,石油烃在栉孔扇贝体内的积累量随暴露时间及污染物种类及浓度的变化发生着动态变化,且不同浓度处理组间差异很大,当石油烃浓度固定为0.6 mg/L时,不同处理浓度组的Cu、Pb及Cu与Pb组合都促进了栉孔扇贝对石油烃的积累,但低处理浓度组的Cu、高处理浓度组的Pb、低处理浓度组的Cu与Pb组合更有利于促进栉孔扇贝对石油烃的积累。[结论]石油烃与Cu、Pb复合污染条件下,石油烃在栉孔扇贝体内的积累状况比单一石油烃污染条件下要复杂得多。     

有机化合物的构性相关分析Ⅰ.烯烃和炔烃的构性相关分析

阐述了烯烃和炔烃分子中的 π-分子轨道 ,并且根据有机化合物的构性相关理论对烯烃和炔烃进行了系统的构性相关分析。经过分析将烯烃和炔烃的化学性质归纳成为 3大类 :官能团的反应 ,烃基的反应和端基炔的特殊反应 ,从而增强了烯烃和炔烃化学的规律性和科学性。     

重迎茬大豆根区土壤有机化合物的GCM/S分析

采用GC M/S分析法,鉴定了重迎茬大豆成熟期根区土壤有机化合物。结果表明,在重迎茬土壤中存在有机酸、醇、酯、酮、醛、苯、酚和烃类等有机化合物,其中很多被报道是化感物质,重茬化感物质种类远多于迎茬。重迎茬土壤中的化感物质种类多与大豆根系分泌物、根茬腐解产物、地上部水浸物中的化感物质相同。     

GC-MS法鉴定漾濞泡核桃壳中挥发性化学成分

[目的]研究漾濞泡核桃壳中挥发性成分的化学组成。[方法]采用水蒸气蒸馏法提取漾濞泡核桃壳中的挥发性成分,并用气相色谱-质谱联用仪（GC-MS）对漾濞泡核桃壳中挥发性成分进行分离和鉴定。[结果]确定了其中20个组分的化学结构和相对含量。漾濞泡核桃壳中挥发性成分主要为脂肪酸及脂肪烃类物质,占总挥发油的50.41%。其中,含量最高的棕榈酸占总挥发油的25.46%。含量较高的物质还有蒽（4.41%）、亚油酸（4.37%）、二苯并呋喃（2.50%）和二十七烷（2.27%）。[结论]漾濞泡核桃壳中挥发性成分主要为脂肪酸及脂肪烃类。     

Seep oil and gas in gulf of Mexico slope sediment

Concentrations in Gulf of Mexico slope sediment of material soluble in methanol and benzene as high as 4.5 percent are shown to be attributable to biodegraded petroleum. Associated carbonate deposits and organic sulfur are the products of the microbial oxidation of petroleum and sulfate reduction. The results of chemical and carbon isotope analyses indicate that high concentrations of hydrocarbon gases, from methane to pentane, are petroleum rather than microbiologically derived. These hydrocarbons, believed to have been produced thermally at depth, probably reached the surface through faults and fractures associated with salt diapirs.     

有机化合物构性相关分析的解析程序

根据有机化合物的构性相关规则 ,用演绎推理的方法建立了有机化合物构性相关分析的解析程序。这一解析程序把有机化合物的构性相关分析归纳成 5个步骤 ,即写出靶结构式 ,找出官能团 ,分析官能团和烃基中所含的每 1根化学键 ,考察分子中各结构单元之间产生的相互影响 ,最后分类总结出有机化合物的全部性能。     

香米在加工过程中香气成分的变化

为研究稻米加工工艺对香米香气成分的影响,采用SDE法对加工过程中香米香气成分的变化进行了分析.研究结果表明,随着碾磨程度的提高,香米中香气成分的损失越大,由谷糙分离米至成品米,杂环类、酮类、酯类、烃类、醛类及醇类香气成分的含量减少,分别减少了71.52%,29.70%,27.64%,27.38%,26.83%,20.00%;而酸类香气成分的含量却呈增加的趋势,增加了21.77%.     

Rare-earth oxides of manganese and cobalt rival platinum for the treatment of carbon monoxide in auto exhaust

The perovskite-like compounds RE(1-X)Pb(5)MnO(3) and RECoO(3), where RE (rare earth) is lanthanum, praseodymium, or neodymium, are active catalysts for the oxidation of carbon monoxide. Crushed single crystals of these compounds compare favorably with commercial platinum catalysts in initial activity and lifetime. Therefore, these compounds are promising substitutes for platinum in devices for the catalytic treatment of auto exhaust.