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91.
The chemical composition of the essential oil ofHaplophyllum myrtifoliumBoiss., endemic to Turkey, was examined by GC/MS. Ninety-seven compounds were characterized with linalool (12.8%), -caryophyllene (10.3 %), and methyleugenol (5.9 %) as the main constituents.  相似文献   
92.
汪杰  涂永善  杨朝合 《催化学报》2003,24(6):452-456
 采用阳离子表面活性剂十六烷基三甲基溴化铵为模板剂,以正硅酸乙酯为硅源,以硫酸铝为铝源,水热合成了以催化油浆窄馏分为添加剂的高比表面积Al-MCM-41介孔分子筛,并利用XRD,HREM,TG-DTA及N2吸附-脱附等测试手段对合成样品进行了表征.合成的Al-MCM-41分子筛的比表面积和孔体积分别达到1295m2/g和1.5cm3/g,其平均孔径为4.3nm.重点研究了Al-MCM-41分子筛结晶度、晶胞参数、比表面积、孔体积及平均孔径等结构性质随催化油浆窄馏分添加量及其组成的变化规律,并从合成机理上进行了解释.  相似文献   
93.
直接甲醇燃料电池阴极电催化剂的研究进展   总被引:8,自引:0,他引:8  
直接甲醇燃料电池(DMFC)功率密度高,燃料甲醇价格低廉、储存和携带方便,特别适合作为电动车和小型电子设备的电源,是目前燃料电池研究领域的一个热点。本文介绍了40年来DMFC阴极电催化剂的发展历史及现状,并针对目前严重影响DMFC性能的“甲醇透过”问题,阐述了研制耐甲醇阴极电催化剂的重要性,讨论了今后DMFC阴极电催化剂的发展趋势。  相似文献   
94.
吸热碳氢燃料裂解镧改性混合型催化剂的研究   总被引:3,自引:0,他引:3  
制备了吸热型碳氢燃料NNJ-150和镧离子交换改性的USY、ZSM-5分子重申及混合分子筛,考察了NNJ-150在USHY、HZSM-5和两者混合物以及镧改性单分子筛和混合分子筛催化剂上的裂解反应。结果表明,ZSM-5分子筛中添加镧,对NNJ-150的单分子裂解反应有明显影响;混合分子两种分子筛之间存在协同作用,低温(500℃)下,LaUSY LaZSM-5(75:25)混合分子筛对低碳烯烃的选择性较高(41.48%),催化剂寿命较长(35min以上),能有效提高吸热型碳氢燃料NNJ-150的吸热能效。  相似文献   
95.
The root of Carlina acanthifolia All. (Asteraceae) contained 1.0% of essential oil (expressed in g per 100 g of dried plant material). Using GC and GC/MS, nine components were identified (100% of total oil). The structure of benzyl 2-furylacetylene (carlina oxide), which is the principal component of the oil (91.5%), was spectrometrically identified. __________ Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 331–332, July–August, 2005.  相似文献   
96.
微波辅助提取-GC/MS联用分析苍耳子中油脂成分的研究   总被引:2,自引:0,他引:2  
采用微波辅助提取-GC/MS联用分析苍耳子中的油脂成分.以V(环已烷):V(丙酮)=1:1为提取溶剂,优化了微波辅助提取的条件.以正二十烷为内标,鉴定出了13种油脂成分,各组分相对保留时间的相对标准偏差(RSD)小于0.15%,相对峰面积的RSD<3.0%.对不同批次以及不同产地的苍耳子样品进行了对比研究.该方法可用于苍耳子的鉴定和质量控制.  相似文献   
97.
Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.  相似文献   
98.
The oleoresin of Pistacia atlantica var. mutica, growing in different regions of Iran, is a popular naturally occurring chewing gum and has been used traditionally in the treatment of peptic ulcer. The GC-MS analysis of the essential oil, obtained from steam distillation of the oleoresin of P. Atlantica var. mutica, has led to the identification and quantification of eleven terpenoids, -pinene (70%), -pinene (1.94%), 3-carene (0.2%), carveol (2.18%), epoxypinene (2.15%), limonene oxide (9%), myrtenol (5.31%), limonene (0.62%), citral (5.72%), -phellandrene (0.2%), and -myrcene (0.3%). The total amount of essential oil obtained was 22% v/w which is higher than any other species of the genus Pestacia.  相似文献   
99.
Developments of intermediate-temperature solid oxide fuel cells (IT SOFCs) require novel anode materials with a high electrochemical activity at 800–1070 K. The polarization of cermet anodes, made of nickel, ceria and yttria-stabilized zirconia (YSZ) and applied onto a YSZ solid electrolyte, can be significantly reduced by catalytically active ceria additions, the relative role of which increases with decreasing temperature. Further improvement is observed when using Ce0.8Gd0.2O2– (CGO) having a high oxygen ionic conductivity instead of undoped ceria, owing to enlargement of the electrochemical reaction zone. Nanocrystalline CGO powders with grain sizes of 8–35 nm were thus synthesized via the cellulose-precursor technique and introduced into Ni–CGO–YSZ cermets, and tested in contact with a (La0.9Sr0.1)0.98Ga0.8Mg0.2O3– (LSGM) electrolyte at 873–1073 K. The results showed that the anode performance can be enhanced by additional surface activation, in particular by impregnation with a Ce-containing solution, and also by incorporation of YSZ, which probably acts as a cermet-stabilizing component. The overpotential of the surface-modified Ni–CGO (25 wt%–75 wt%) anode in a 10% H2/90% N2 atmosphere was approximately 110 mV at 1073 K with a current density of 200 mA/cm2.Presented at the OSSEP Workshop Ionic and Mixed Conductors: Methods and Processes, Aveiro, Portugal, 10–12 April 2003  相似文献   
100.
Many standard and official sample digestion procedures for trace metal determination are carried out in open vessels on hot plates. A new procedure for the determination of trace metals by flame atomic absorption spectrometry or inductively coupled plasmaatomic emission spectrometry in beer samples was developed to be performed in closed reactors assisted by microwaves. The results are compared with the ones obtained by other procedures by means of the analysis of the variance. The differences between the procedures are attributed to residual organic matter. Voltammetry, absorption molecular spectrophotometry and high pressure liquid chromatography with a photodiode array detector are used to study the nature of these residues. Nitrobenzoic acids, phenolic acids and other organic compounds are often present after digestion. The results obtained are related to the precision in metal determination by atomic spectrometry. The need for elaboration of certified reference materials for trace metals in beer is suggested.  相似文献   
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