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41.
刺芫荽挥发性成分研究   总被引:1,自引:0,他引:1  
以野生刺芫荽为原料,采用同时蒸馏萃取法提取其挥发性成分,应用气相色谱—质谱法对提取物进行化学成分分析.实验结果表明,野生刺芫荽提取物中共鉴定出24种化合物,占总峰面积的65.94%,质量分数达到1.00%以上的有6种物质,其挥发性成分中醛酮类化合物相对质量分数达到58.05%.  相似文献   
42.
Ambipolar polymer semiconductors are potentially serviceable for logic circuits, light-emitting field-effect transistors (LFETs) and polymer solar cells (PSCs). Although several high-performance ambipolar polymers have been developed, their optoelectronic devices are generally processed from toxic chlorinated solvents. To achieve the commercial applications of organic FETs (OFETs), the polymers should be processed from nonchlorinated solvents, instead of chlorinated solvents. However, most conjugated polymers show poor solubility in nonchlorinated solvents. It is of great importance to develop ambipolar polymers that can be processed from nonchlorinated solvents. Here, we develop a nonchlorinated solvent processed polymer named poly[7-fluoro-N, N-di(4-decyltetradecyl)-7-azaisoindigo-6,6-(thieno[3,2-b]thiophene-2,5-diyl)-7‴-fluoro-N, N‴-di(4-decyltetradecyl)-7-azaisoindigo-6,6‴-([2,2-bithiophene]-5,5-diyl)] (PITTI-BT) by designing a monomer with a large molar mass. The polymer displays good solubility in p-xylene (PX). Well-aligned films of PITTI-BT are achieved by an off-center spin-coating (SC) method. Based on the high-quality films, the OFETs fabricated from PX solution achieve record ambipolar performance with hole and electron mobilities of 3.06 and 2.81 cm2 V−1 s−1, respectively. The combination of nonchlorinated solvents and good alignment process offers an effective and eco-friendly approach to obtain high-performance ambipolar transistors.  相似文献   
43.
Traditional recycling processes of LiCoO2 rely on destructive decomposition, requiring high-temperature roasting or acid leaching to extract valuable Li and Co, which have significant environmental and economic concerns. Herein, a direct repairing method for degraded LiCoO2 using a LiCl–CH4N2O deep eutectic solvent (DES) was established. The DES is not used to dissolve LiCoO2 but directly serves as a carrier for the selective replenishment of lithium and cobalt. Replenishment of lithium restores LiCoO2 at different states of charge to a capacity of 130 mAh/g (at 0.1 C rate), while replenishing the cobalt increases the capacity retention rate of 90% after 100 cycles, which is comparable to pristine LiCoO2. The DES is collected and reused multiple times with a high repair efficiency. This process reduces energy consumption by 37.1% and greenhouse gas emissions by 34.8% compared with the current production process of LiCoO2, demonstrating excellent environmental and economic viability.  相似文献   
44.
This research on the solvent effects of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine (MDOP) in binary solvent systems on the infrared spectra for MDOP in n-hexane/CHCl3 mixture solvents showed that there were three forms of carbonyl stretching vibration band [ν(C=O)] of MPOP as the mole fraction of CHCl3 in the binary solvents changes. In pure n-hexane solvent, the ν(C=O) of MDOP appeared at a relatively high wavenumber. With CHCl3 added, the ν(C=O) shifted to lower wavenumbers. Two new bands were observed over a certain range of mixture solvent compositions. The origin of the bands was discussed in the terms of two kinds of hydrogen bond together with their individual dependence on mixture composition. Comparisons were drawn for the solvent sensitivities of ν(C=O) for propanone. Project supported by the Analysis and Measurement Foundation of Zhejiang Province, China.  相似文献   
45.
建立顶空气相色谱法控制氟马西尼中有机溶剂乙醇、乙醚、二氯甲烷残留量的分析方法。方法:采用DB-624石英毛细管柱,FID离子化检测器,以90%的二甲亚砜水溶液为溶剂。结果:乙醇在12.60~75.60ug/ml(630ppm~3780ppm)的浓度范围内,r为0.9998乙醚在12.79~76.74ug/ml(639.5ppm~3837ppm)的浓度范围内,r为0.9999二氯甲烷在2.54~15.24ug/ml(127ppm~762ppm)的浓度范围内,r为0.9997,大于规定的0.99;定量限试验中,信噪比符合规定,能够达到定量检测及检出的要求;各浓度下的乙醇、乙醚、二氯甲烷平均回收率均在90%-110%范围内。结论:该方法专属性好,精密度、准确度都符合要求,方法可靠,可用于原料药氟马西尼中有机溶剂乙醇、乙醚、二氯甲烷的残留量的控制。  相似文献   
46.
Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%?84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%?66.00%).  相似文献   
47.
目的:观察乙醇、1.2-丙二醇、二甲基亚砜、吐温80对小鼠骨髓基质细胞(BMSC)、粒-巨噬系祖细胞(CFU-GM)和内皮细胞系细胞(BMEC)体外生长和活力的影响。并分析量效关系。方法:分别设置不同终体积分数有机溶剂的细胞培养体系及其对照。检测成纤维形成单位(CFU-F)和CFU-GM的集落生成率,用MTT比色法和台盼蓝排斥试验测定BMSC和BMEC的细胞活力和活细胞率。结果:乙醇为1.6%、丙二醇为1.6%、二甲基亚砜为2%、吐温80为0.005%-0.01%时,CFU-F和CFU-GM集落产率与对照纽相比显著降低(P〈0.05或〈0.01)。乙醇和丙二醇为02%、0.4%、二甲基亚砜为0.5%-1.0%、吐温80为0.002%-0.005%时,BMSC和CFU-GM的细胞活力和活细胞率与对照组相比显著减低(P〈0.05或〈0.01)。随着这几种有机溶剂在上述体积分数上增加,各相应检测指标的减低率递增。结论:乙醇、丙二醇、二甲基亚砜,吐温80在细胞培养体系中达一定含量时,对小鼠骨髓BMSC、CFU-GM和BMEC细胞具有明显的生长抑制作用和(或)细胞毒性效应。含量增高则效应更显著。  相似文献   
48.
金属活动顺序的应用是有条件的。常用的金属活动顺序表是根据金属在水溶液中电极电势值由小到大排列而成的,通常情况下不特别指明溶剂是“水”。然而,溶剂不同时,金属的电极电势也不相同,应予注意。以碱金属在液氨中的活泼性问题为例,讨论溶剂本身的氧化还原性对金属活动性的影响。  相似文献   
49.
提出了用无机盐代替卟啉铁作标准试剂,以甲苯—冰醋酸(1∶3)(体积比)为混合溶剂,火焰原子吸收法直接测定原油中的含量的新方法,与灰化法相比,方法简便、省时,精密度好,回收率高,经对两种原油进行了铁的测定证明,结果与灰化法相吻合  相似文献   
50.
β2-兴奋剂是一类化学合成的苯乙醇胺类衍生物,种类繁多,性质各异。研究了在不同的PH状态下,用不同有机溶剂从水中萃取7种β2-兴奋剂,利用高效液相色谱仪测定萃取率,气相色谱-质谱仪同时验证,从而得出7种β2-兴奋剂在各种溶剂中的萃取率,为β2-兴奋剂在多残留检测方面的研究提供可靠有效的数据支持。  相似文献   
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