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991.
大庆渣油族组分非等温热反应的研究 总被引:2,自引:0,他引:2
采用动态热重分析法在升温速率为6.2K·min ̄(-1)及惰性气流量100cm ̄3·min ̄(-1)的条件下,对大庆渣油族组分的热转化行为进行了考察,获得了族组分的热转化速率峰值、速率峰值处的反应温度、转化率和剧裂分解温度区间等动力学基本数据以及各族组分的生焦性能。数据分析表明,族组分的热反应活性顺序为:饱和分>胶质>芳香分>沥青质。在大庆渣油族组分热转化的两个温区内,采用分段一级动力学模型较好地拟合了实验数据,确定了各族组分在两个温区内的热反应动力学参数。 相似文献
992.
Xin‐Zhou Yang Li‐Gen Lin Chun‐Ping Tang Yong‐Qiang Liu Yang Ye 《Helvetica chimica acta》2007,90(2):318-325
Five new nonalkaloid constituents, a neolignan, japonin A ( 1 ), a macrocyclic lactone, japonin B ( 2 ), a (phenylethyl)benzoquinone, japonin C ( 3 ), a phenanthraquinone, japonin D ( 4 ), as well as a dihydrostilbene, stilbostemin M ( 5 ), were isolated from the roots of Stemona japonica, together with eight known compounds. Their structures were established by spectroscopic analyses. 相似文献
993.
Xiang‐Gao Meng Chun‐Shan Zhou Li Wang Chang‐Lin Liu 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):o667-o670
5‐Sulfosalicylic acid (5‐SSA) and 3‐aminopyridine (3‐APy) crystallize in the same solvent system, resulting in two kinds of 1:1 proton‐transfer organic adduct, namely 3‐aminopyridinium 3‐carboxy‐4‐hydroxybenzenesulfonate monohydrate, C5H7N2+·C7H5O6S−·H2O or 3‐APy·5‐SSA·H2O, (I), and the anhydrous adduct, C5H7N2+·C7H5O6S− or 3‐APy·5‐SSA, (II). Both compounds have extensively hydrogen‐bonded three‐dimensional layered polymer structures, with interlayer homo‐ and heterogeneous π–π interactions in (I) and (II), respectively. 相似文献
994.
One new saponin, named capilliposide D (1), and a known saponin, candidoside (2), were isolated from the whole plants of Lysimachia capillipes. Their structures were determined by 1D and 2D NMR, MS techniques, and chemical methods.
Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 268–270, May–June, 2006. 相似文献
995.
合成了一种含吡唑啉酮的三脚架结构化合物 1,1,1 三 { 1′ [2′ 氧杂 5′ 氧代 5′ ( 1″ 苯基 3″ 甲基吡唑啉酮 4″ 基 )戊基 ] }丙烷 (H3 L)及其 7个稀土配合物。通过元素分析、摩尔电导、质谱、红外光谱、核磁共振谱、荧光光谱等对H3 L及其稀土配合物的组成及性质进行了表征。分析结果表明 :H3 L的分子式为C45H50 N6O9,配合物的组成比为REL·0 5H2 O (RE =La ,Sm ,Eu ,Gd ,Tb ,Dy ,Yb) ;该三脚架形配体分别以醚氧、烯醇氧及吡唑酮环上的羰基氧与稀土离子进行配位 ,形成内配型配合物。荧光光谱分析表明SmL·0 5H2 O ,EuL·0 5H2 O ,TbL·0 5H2 O ,DyL·0 5H2 O配合物具有三价稀土离子的特征线状荧光 ,其中TbL·0 5H2 O的荧光强度最强 ,表明T(配体 )→5D4(Tb)能级更为匹配 ,从而进行分子内能量有效传递 ;由EuL·0 5H2 O的荧光光谱图形推测 ,Eu3 +离子在该配合物中处于非对称中心 相似文献
996.
以乙酰丙酮镍、油酸、油胺为原料,十八烯为溶剂,聚乙烯吡咯烷酮为表面活性剂,采用溶剂热法,在不同反应条件制备了纳米级氧化镍材料.通过X射线衍射(X-ray diffraction,XRD)、透射电子显微镜(Transmission electron microscope,TEM)、紫外-可见光吸收光谱(Ultraviolet-visible spectroscopy,UV-Vis)光谱分析以及塔菲尔(Tafel)测试考察了反应物比例、保温时间、表面活性剂(PVP)、油胺的量对产物微结构、粒径、形貌、光学以及电化学活性性能的影响.实验结果表明:在反应物n[Ni(acac)2]∶n(OA)=1∶2、添加剂PVP质量分数为1.66%、油胺物质的量为30 mmol、200℃下保温8 h时,可获得粒径约为30~40 nm纯相氧化镍,具有最佳电化学活性,交换电流密度为J0=1.23×10-2 mA·cm-2. 相似文献
997.
Rh- or Ru-catalyzed highly enantioselective hydrogenation of N-phthaloyl enamides is presented. Electron-rich TangPhos and DuanPhos are found to be effective ligands for Rh-catalyzed hydrogenation of α-aryl enamides and up to 99% ee has been achieved. In contrast, for the hydrogenation of α-alkyl enamide, the Ru-C3-TunePhos complex is more effective and up to 69% ee can be observed. This work is the first report of the hydrogenation of N-phthaloyl enamides. 相似文献
998.
Lijun X Bochu W Zhimin L Chuanren D Qinghong W Liu L 《Colloids and surfaces. B, Biointerfaces》2005,40(1):25-29
We studied the LAS degradation of immobilized Pseudomonas aeruginosa with low-intensity ultrasonic and the influence of original LAS concentration, pH, rotary velocity and different conditions of low-intensity ultrasonic irradiation on the degradation of LAS. In our experiment, the degradation rate of LAS was the main index. We found that low-intensity ultrasonic irradiation could improve the metabolism of microorganism cells and promote the LAS biodegradation of immobilized cells. In the experiment, 50 mg/l LAS were used to simulate wastewater, and low-intensity ultrasonic was considered. We found the influence was obvious, and the optimal degradation rate was acquired when the conditions of ultrasonic were frequency 24 kHz, power 8 W, stimulation time 5 s, intermissive time 30 s, and total time 10 min. The LAS degradation rate of immobilized cells with ultrasonic were respectively 40% and 9.5% higher than that of the suspending cells and immobilized cells without irradiation. 相似文献
999.
用TRP技术研究了以全硅MCM-41(Si-MCM-41)和HNO3交换的全硅MCM-41(H-MCM-41)为载体制备的Ni-Mo、Co-Mo和Ni-W加氢脱硫(HDS)催化剂的还原性能,并以0.8(wt)%二苯并噻吩(DBT)的十氢萘溶液为模型化合物,在高压固定床反应器上考察了上述催化剂的加氢脱硫(HDS)反应性能。结果表明,Si-MCM-41经稀HNO3交换后,所担载的Ni-Mo和Ni-W催化剂还原性能、HDS活性和加氢活性有显著变化,但对Co-Mo催化剂影响不大。这说明在Ni-Mo/H-MCM-41和Ni-W/H-MCM-41中可能存在氢溢流现象,DBT的HDS活性与载体表面酸性和氢溢流有关。 相似文献
1000.
The electroosmotic flow through an annulus is analyzed under the situation when the two cylindrical walls carry high zeta potentials. The analytical solutions for the electric potential profile and the electroosmotic flow field in the annulus are obtained by solving the Poisson-Boltzmann equation and the Stokes equation under an analytical scheme for the hyperbolic sine function. A mathematical expression for the average electroosmotic velocity is derived in a fashion similar to the Smoluchowski equation. Hence, a correction formula is introduced to modify the Smoluchowski equation, taking into account contributions due to the finite thickness of the electric double layer (EDL) and the geometry ratio-dependent correction. Specifically, under a circumstance when the two annular walls are oppositely charged, the flow direction can be determined from the sign of such correction formula, and there exists a zero-velocity plane inside the annulus. With the assumption of large electrokinetic diameters, the location of the zero-velocity plane can be estimated from the analytical expression for the velocity distribution. In addition, the characteristics of the electroosmotic flow through the annulus are discussed under the influences of the EDL parameters and geometric ratio of the inner radius to the outer radius of the annulus. 相似文献