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51.
目的 研究瑶药野柠檬根的挥发性成分.方法 采用水蒸气蒸馏法提取野柠檬根的挥发油,并用GC-MS进行测定,结合计算机检索技术对分离的化合物进行结构检索,应用色谱面积归一化法计算各成分的相对含量.结果 从野柠檬根挥发油中分离并检索出37种化学成分,其中相对百分含量大于3%的分别确定为α-法呢烯、榄香醇、β-马啊里烯、β-桉叶醇、Tticyclo[2.2.1.0(2,6)]heptane,1,7-demethyl-7- (4-methyl -3-pentenyl).结论 该植物中37个挥发性成分均为首次报道,占挥发油气化产物的91%. 相似文献
52.
This study aimed to explore the wear characteristics and evolution mechanisms of large-scale wind power gears under the impact load of particles of the three-body abrasive Al2O3 (0.2 mg/mL) from four aspects: oil analysis, vibration analysis, amount of gear wear, and tooth-surface-wear profile analysis. A magnetic powder brake was used to simulate the actual working conditions. Combined with the abrasive particle monitoring and the morphology analysis of the tooth-surface-wear scar, by setting quantitative hard particles in the lubricating oil, the gears are mainly operated in the abrasive wear state, and wear monitoring and wear degree analysis are carried out for the whole life cycle of the gears. Oil samples were observed and qualitatively analyzed using a particle counter, a single ferrograph, a metallographic microscope, and a scanning electron microscope. The experiments demonstrate that the initial hard particles have a greater impact in the early wear stage of the gears (<20 h), and abrasive particle concentration increases by 30%. This means that Al2O3 particles accelerate the gear wear during the running-in period. The loading method of the impact load on the oblique gear exacerbates the abrasion particle wear and expands the stress concentration, which reduces the surface of large milling particles on the surface, and reduces the width of the tooth (the part above the pitch line is severely worn), which causes the gear to break into failure. The research provides help for analyzing the mechanism of abrasive wear of gears and predicting wear life. 相似文献
53.
GC—MS法鉴定银柴胡挥发油的化学成分 总被引:5,自引:0,他引:5
目的 研究银柴胡的挥发油化学成分。方法 采用气相色谱-质谱联用仪(GC-MS)对银柴胡的挥发油化学成分进行了分析鉴定。结果 从分离出的20多个峰中鉴定出17个化学成分。结论 银柴胡挥发油的主要化学成分为2-甲基-5-异丙烯基-2,5-己二烯-1-乙酸酯,去乙酰基蛇形毒素和14-甲基十五烷酸甲酯等成分。 相似文献
54.
55.
目的:探讨薄荷油腹部湿热敷对维持性血液透析患者便秘的疗效。方法将60例维持性血液透析便秘患者随机分为观察组与对照组各30例,观察组患者采用薄荷油腹部湿热敷,对照组给予番泻叶3~6 g泡水顿服,疗程均为2周。观察2组患者的疗效及排便时患者的反应。结果观察组总有效率明显高于对照组,2组比较差异有统计学意义(P〈0.05)。结论薄荷油腹部湿热敷操作简单,无副作用,不仅可以使维持性血液透析患者保持大便通畅,而且可以减少因便秘引起的不适和并发症,进而提高患者的生活质量。 相似文献
56.
57.
Da-Som Kim Seong-Jun Hong Sojeong Yoon Seong-Min Jo Hyangyeon Jeong Moon-Yeon Youn Young-Jun Kim Jae-Kyeom Kim Eui-Cheol Shin 《Nutrients》2022,14(9)
We explored the physiological effects of inhaling basil essential oil (BEO) and/or linalool and identified odor-active aroma compounds in BEO using gas chromatography/mass spectrometry (GC–MS) and GC–olfactometry (GC–O). Linalool was identified as the major volatile compound in BEO. Three groups of rats were administered BEO and linalool via inhalation, while rats in the control group were not. Inhalation of BEO for 20 min only reduced the total weight gain (190.67 ± 2.52 g) and increased the forced swimming time (47.33 ± 14.84 s) compared with the control group (219.67 ± 2.08 g, 8.33 ± 5.13 s). Inhalation of BEO for 5 min (392 ± 21 beats/min) only reduced the pulse compared with the control group (420 ± 19 beats/min). Inhalation of linalool only reduced the weight of white adipose tissue (5.75 ± 0.61 g). The levels of stress-related hormones were not significantly different among the groups. The total cholesterol and triglyceride levels decreased after inhalation of BEO for 20 min (by more than −10% and −15%, respectively). Low-density lipoprotein cholesterol levels were lowered (by more than −10%) by the inhalation of BEO and linalool, regardless of the inhalation time. In particular, BEO inhalation for 20 min was associated with the lowest level of low-density lipoprotein cholesterol (53.94 ± 2.72 mg/dL). High-density lipoprotein cholesterol levels increased after inhalation of BEO (by more than +15%). The atherogenic index and cardiac risk factors were suppressed by BEO inhalation. Animals exposed to BEO and linalool had no significant differences in hepatotoxicity. These data suggest that the inhalation of BEO and linalool may ameliorate cardiovascular and lipid dysfunctions. These effects should be explored further for clinical applications. 相似文献
58.
Sebastian Wiedl Peter Karlinger Michael Schemme Manuela List Holger Ruckdschel 《Materials》2022,15(9)
The necessity for resource-efficient manufacturing technologies requires new developments within the field of plastic processing. Lightweight design using wood fibers as sustainable reinforcement for thermoplastics might be one solution. The processing of wood fibers requires special attention to the applied thermal load. Even at low processing temperatures, the influence of the dwell time, temperature and shear force is critical to ensure the structural integrity of fibers. Therefore, this article compares different compounding rates for polypropylene with wood fibers and highlights their effects on the olfactory, visual and mechanical properties of the injection-molded part. The study compares one-step processing, using an injection-molding compounder (IMC), with two-step processing, using a twin-scew-extruder (TSE), a heating/cooling mixer (HCM) and an internal mixer (IM) with subsequent injection molding. Although the highest fiber length was achieved by using the IMC, the best mechanical properties were achieved by the HCM and IM. The measured oxidation induction time and volatile organic compound content indicate that the lowest amount of thermal damage occurred when using the HCM and IM. The advantage of one-time melting was evened out by the dwell time. The reinforcement of thermoplastics by wood fibers depends more strongly on the structural integrity of the fibers compared to their length and homogeneity. 相似文献
59.
目的 :探讨豆油 [富含 ω- 6多不饱和脂肪酸 ( PUFAs) ]对饲低硒粮大鼠血浆 Cu、Zn、Ca和 Mg含量变化的影响。方法 :用低硒和补硒饲料喂养大鼠 4周 ,补加 5 %豆油后再继续饲养 4周。用原子吸收分光光度计测定大鼠血浆中 Cu、 Zn、 Ca、和 Mg含量。结果 :饲低硒粮和补硒粮组 ,在饲料中添加豆油后 ,大鼠血浆中 Cu、Zn、Ca、和 Mg含量均有不同程度下降。在添加豆油的大鼠 Zn、Mg含量下降更明显 ,Ca、Cu含量虽有所下降 ,但差异无显著性。结论 :饲料中添加豆油 ,使大鼠PUFAs的摄入量增加 ,Cu、Zn、Ca和 Mg含量降低。 相似文献
60.
The single light oil regenerating agent has certain limitations on the performance recovery of aged asphalt. In this study, tung oil, dioctyl phthalate (DOP), C9 petroleum resin, and organic montmorillonite (OMMT) were used to prepare the composite regenerating agent, and its optimal mix proportion was determined by the orthogonal experimental design. The rheological properties and anti-aging performance of reclaimed asphalt were studied by the dynamic shear rheometer (DSR) and bending beam rheometer (BBR); and the Fourier transform infrared (FTIR) spectrometer, gel permeation chromatography (GPC), and scanning electron microscope (SEM) were adopted to explore its microstructure, morphology, and mechanism of action. The results show that with the addition of tung oil composite regenerating agent, the rheological properties of aged asphalt can be effectively recovered, even better than that of base asphalt. By using the complex modulus aging index (CMAI) and phase angle aging index (PMAI) it is found that the anti-aging performance of reclaimed asphalt is better than that of base asphalt. With the optimal content of the tung oil composite regenerating agent, the contents of characteristic functional groups and macromolecular asphaltenes in the aged asphalt can be reduced, indicating that the composite regenerating agent is beneficial to the dispersion and dissolution of polar substances in the aged asphalt. After aging, a large number of wrinkles appear on the surface of the asphalt. However, the addition of the tung oil composite regenerating agent can make the asphalt surface smooth, which indicates that the tung oil composite regenerating agent can restore the microstructure and morphology of aged asphalt to a certain extent. 相似文献