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111.
Density of supercritical CO_2-tetrahydrofuran binary mixture and the partial molar volume of the cosolvent 总被引:1,自引:0,他引:1
The densities of supercritical CO2-tetrahydrofuran (cosolvent) binary mixture weremeasured at temperatures in range of 308.15 to 323.15 K and at pressure up to 16.5 MPa.The concentrations of tetrahydrofuran were from 0 to 0.57 mol/L.The partial molar volume of tetrahydrofuran was calculated based on the relationship between the density of the mixture and the concentration of the cosolvent.It is observed that the partial molar volume of the cosolvent is negative and the absolute value decreases with increasing pressure and the concentration of the cosolvent. 相似文献
112.
本文合成了2,5-二(2-菲基)-[3,2-b]并二噻吩(PhTT), 表征了其基本的物理和化学性质, 制备了相应的有机薄膜晶体管. 相似文献
113.
摘要运用多参考微扰理论(Multireference MΦller-Plesset theory)计算了SSCH3垂直激发能及其S-C与S-S两种断键方式的绝热(Adiabatic)与非绝热(Diabatic)的基态和激发态势能曲线, 研究了在193nm激光作用下SSCH3的光解离过程, 理论计算值与实验值相符. 相似文献
114.
A 285-pomt multi-reference configuration-interaction involving single and double excitations ( MRS DCI) potential energy surface for the electronic ground state of L12H is determined by using 6-311G (2df,2pd)basis set.A Simons-Parr-Finlan polynomial expansion is used to fit the discrete surface with a x2 of 4.64×106 The equn librium geometry occurs at Rc=0.172 nm and,LiHL1=94.10°.The dissociation energy for reaction I2H(2A)→L12(1∑g)+H(2S) is 243.910 kJ/mol,and that for reaction L12H(2A')→HL1(1∑) + L1(2S) is 106.445 kl/mol The inversion barrier height is 50.388 kj/mol.The vibrational energy levels are calculated using the discrete variable representation (DVR) method. 相似文献
115.
纳米材料的制备、性能与应用已成为近年来的研究热点之一犤1犦。由于在催化、光学和电学材料中的广泛应用,超细单分散的金属微粒的制备与性质已引起人们的广泛兴趣。通常制备金属纳米微粒的方法有两种:一是把固体金属材料分裂为纳米尺寸的颗粒,如机械粉碎、电弧放电及金属原子蒸气沉积犤2犦,用这种方法制备的金属微粒粒径一般都比较大,且粒子尺寸分布宽,另一种是把金属原子制成纳米尺度的颗粒,如乳液聚合法犤3犦、热解犤4犦、γ-射线辐照犤5犦、脉冲电沉积犤6犦和化学还原犤7犦等,这种方法制备的微粒粒径通常分布窄且粒子小… 相似文献
116.
Two New C—21 Steroidal Glycosides from Cynanchum aurichulatum 总被引:2,自引:0,他引:2
Two new C-21 steroidal glycosides, cynanauriculoside I and cynanauriculoside Ⅱ, were isolated from the roots of Cynanchum aurichulatum. Their structures were established using spectroscopic methods including one and two-dimensional NMR. 相似文献
117.
A series of novel two-dimensional (2D) and three-dimensional (3D) praseodymium coordination polymers, namely, {[Pr3(PDA)4(HPDA)(H2O)8] x 8H2O}n (2), {[Pr2(PDA)3(H2O)3] x H2O}n (3), {[Pr(PDA)(H2O)4] x ClO4}n (4), and { [Pr2(PDA)2(H2O)5SO4] x 2H2O}n (5) (PDA = pyridine-2,6-dicarboxylic anion), was designed and synthesized under hydrothermal conditions. Complexes 1-3 (chainlike polymer, {[Pr(PDA)(HPDA)(H2O)2] x 4H2O}n (1) was also obtained independently by us, although it has been reported recently by Ghosh et al.) were fabricated successfully by simply tuning the Pr/PDA ratio and exhibited various and intriguing topological structures from a 1D chain to a 3D network. While the synthetic strategy of 5 was triggered and further performed only after 1 was structurally characterized. The complexes were characterized by X-ray single-crystal determination, spectroscopic, and variable-temperature magnetic susceptibility analyses. In complex 2 an unusual nanosized square motif as a building block constructed by eight Pr ions was further assembled into a highly ordered 2D grid compound. In complex 3 the decanuclear Pr metal-based structure as a repeat unit interpenetrated to form a novel 3D polymer. Complex 4 was a 3D network polymer fabricated through a hexanuclear Pr ring as a building block, and ClO4- anions as guests were trapped in the cavity. In complex 5 six Pr atoms, two SO4(2-) anions, and carboxylic oxygen bridges constructed an intriguing rectangle structure as a repeat unit in the grid to form a 2D coordination polymer in which the unique bi-bidentate coordination mode of SO4(2-) anion was observed. 相似文献
118.
有机相中α-氰基-3-苯氧基苄醇乙酯的酶促醇解反应 总被引:1,自引:1,他引:1
研究了有机相中脂肪酶催化α-氰基-3-苯氧基苄醇乙酯的醇解化反应。制备α -氰基-3-苯氧基苄醇。考察了酶、溶剂、醇、醇用量、溶剂水含量以及底物浓度等 因素对反应的影响,结果表明Novozym435脂肪酶催化活性最高,经实验确定的最佳 条件为:脱水甲苯为溶剂,正辛醇为酰基受体,正辛醇、酯的摩尔比为1.5:1,酶 量为8 mg/mL时的最佳底物浓度为108.13 mmol/L,在上述条件下反应30 h酯的转化 率 > 96%。 相似文献
119.
A thin film of manganese hexacyanoferrate (MnHCF) was electrochemically formed on a glassy carbon (GC) electrode to prepare a chemically modified electrode (CME). The mechanism of film formation of MnHCF and its growth process were investigated in detail by cyclic voltammetry. The results show that the stoichiometric composition of MnHCF is Mn^ⅢFe^Ⅲ(CN)6, an analogue of prussian yellow. There exist three clear-cut stages in the whole modification process and the last stage is indispensable to the fabrication of homogenized, stable MnHCF film and must last for an appropriate time. The surface morphology of MnHCF/GC electrode was characterized by scanning electron microscopy (SEM), which further verified the effective deposition of MnHCF film on GC. The kinetic constants of MnHCF/GC electrode process were also evaluated. The resulting MnHCF film modified electrode presented good stability and high electrocatalytic activity toward the oxidation of H2O2, indicating that MnHCF film possesses function of catalase and can be expected for analytical purposes. 相似文献
120.