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51.
The rotation dynamics of C60 molecules in organic superconductor K3C60 has been investigated from the viewpoint of intramolecular interaction.It is determined that the rotation of C60 at room temperature has been frozen up within a small region of rotation angle (0→50°),and pointed out that the reason for the freeze is the physical interaction rather than the geometrical hindrance.The computations of the interactions for alkali-doped compounds A3-xAxC60(x=1,2,3;A,A'= K,Rb,Cs) other than K3C60 have also been carried out.From the obtained results,it is seen that the superconducting transition temperatures Tc are strongly connected with the interactions in them,and this observation is consistent with the discovery of the correlation between Tc and lattice constants a 相似文献
52.
在微波辐射下用低温固相配位反应合成出多核配合物.通过元素分析确定配合物组成为La2(CoL2)3(L=-S2CNHCH2CO-2),并研究了该配合物的摩尔电导、红外光谱、紫外光谱和核磁共振氢谱.配合物的抗癌活性测定结果表明Co(HL)2和La2(CoL2)3有一定的抗癌活性;La2(CoL2)3对肝癌细胞生长有显著抑制作用,对正常肝细胞的生长无影响. 相似文献
53.
54.
A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717^# resin, then Fe(Ⅲ) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×10^4L/mol.cm, which is 16 times higher than that of liquid phase spectrophotornetry, most coexisting ions do not influence the determination. The detection limit for Fe(Ⅲ) is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe(Ⅲ)]. The calibration curve is linear in the range of 0-25μg/50mL. The preposed method was applied to the determination of Fe(Ⅲ) in water sample with satisfactory results. 相似文献
55.
Tautomeric equilibrium of ethyl acetoacetate in compressed CO2 + ethanol and CO2 + methanol mixtures
Li Z Mu T Jiang T Du J Zhao G Zhang J Han B Huang Y 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(5):1055-1059
Tautomerism equilibrium of ethyl acetoacetate (EAA) in compressed CO2 + methanol and CO2 + ethanol mixtures was studied by UV-Vis spectroscopy at 308.15 K and different pressures. The volume expansion coefficient (alpha) of the solvents at different pressures was also determined. The relative permittivity (epsilon) of CO2 + methanol and CO2 + ethanol mixtures at different conditions was calculated using the Kc and Onsager solvent parameter. The equilibrium constant (Kc) of EAA in the binary mixtures increases considerably with increasing pressure or volume expansion coefficient. The relative permittivity or the polarity of the binary mixtures decreases sharply with increasing volume expansion coefficient in the range of 0 < alpha < 1.5. However, as the volume expansion coefficient exceeds 1.5, the relative permittivity decreases slowly. In other words, the dissolution of CO2 in the polar solvents can reduce the polarity of the solvents significantly in the low volume expansion coefficient range, and the polarity of the solution is not sensitive to the volume expansion coefficient as its value is large enough. The difference in polarity of the two solvents reduces with increasing pressure and becomes negligible after volume expansion coefficient exceeds about 2.5. 相似文献
56.
57.
Jaehong Park Chul Kim Jimin Jeong Sang-Gu Lee Jungho Hwang 《Journal of Electrostatics》2011,69(2):126-132
In this study, a unipolar charger for generating highly charged microparticles was designed and its performance was evaluated both theoretically and experimentally. The measured particle charge number and corona current of the charger were in good agreement with the theoretical results from FLUENT. The experimentally determined average particle charge number of 1 μm PSL under an applied voltage of 8 kV was 128, which agreed well with the theoretically predicted and simulated values of 118 and 121, respectively. Computational calculations revealed the average charge of 10 μm particles to be 7560 at an applied voltage of 8 kV. 相似文献
58.
Jimin Yoon Won Gun Kwack Wang-Seob Shim Jun Kyu Lee Dong Kee Jang Namyi Gu Ji-Yoon Cho Kyung-Tae Lee Eun Kyoung Chung 《Biomedical chromatography : BMC》2020,34(12):e4957
Cefpiramide is frequently used to treat biliary infections. However, no bioanalytical method has been validated to quantitate cefpiramide in human samples, particularly in bile. Therefore, this study was conducted to develop a simple, selective and validated high-performance liquid chromatographic method to determine cefpiramide in human plasma and bile. A protein precipitation procedure was used to extract cefpiramide and cefoperazone (internal standard, IS) from 200 μl of plasma and bile. Utilizing a Capcell Pak C18 column (4.6 × 250 mm), cefpiramide and IS were separated using the timed-gradient mobile phase consisting of 0.1 m sodium acetate (pH 5.2) and acetonitrile at a flow rate of 1 ml/min with photodiode array detector (wavelength set at 273 nm). The calibration curves showed linearity at concentrations ranging from 1 to 150 μg/ml in both plasma and bile (r2 > 0.999). The within- and between-run coefficients of variation (CVs) for plasma samples were 0.570–4.43 and 1.10–2.76%, respectively; for bile samples, the within- and between-day precision (CV) was 0.814–6.34 and 2.05–4.00%, respectively. Our newly developed bioanalytical method was successfully employed to quantify cefpiramide concentrations in both plasma and bile at multiple time points in patients with acute cholangitis. 相似文献
59.
A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717# resin, then Fe(Ⅲ) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×104L/mol. cm, which is 16 times higher than that of liquid phase spectrophotometry, most coexisting ions do not influence the determination. The detection limit for Fe(Ⅲ) is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe(Ⅲ)]. The calibration curve is linear in the range of 0~25μg/50mL. The preposed method was applied to the determination of Fe(Ⅲ) in water sample with satisfactory results. 相似文献
60.
基于国际热核聚变实验反应堆磁约束聚变-裂变混合能源系统次临界包层的物理-热工设计结果,提出了聚变-裂变混合堆次临界包层燃料区结构设计方案,包括纵骨支撑结构、燃料区结构和锆包壳结构。运用Pro/e建模软件建立了次临界包层燃料区结构模型,并利用ANSYS-workbench mechanical有限元分析软件对纵骨式支撑结构开展了初步力学分析,得到了燃料部件和纵骨式多层支撑结构的最大Tresca应力值、应力分布云图和总变形量,其中最大应力为87.04 MPa,最大变形量为0.17mm。按照第3强度理论校核,计算结果表明纵骨式次临界包层结构各部件能够满足强度要求。 相似文献