Calculations of the vibrational frequency and isotopic shift of UF6 and U2F6

Molecular structure, vibrational frequency and infrared intensity of UF6 are investigated by using the revised Perdew Burke-Enzerhof function with the triple-zeta polarized basis set. The calculation results are in good agreement with the experimental values and indicate the existence of a stable U2F6 molecule with a multiple bonded U2 unit. The calculation results also predict that the D3d symmetry of U2F6 is more stable than D3h. The optimized geometries, vibrational frequencies, and infrared intensities are also reported for U2F6 molecules in D3d symmetry. In addition, the isotopic shift of vibrational frequencies of the two molecules under isotopic substitution of uranium atom are also investigated with the same method. The U2F6 molecule is predicted to be better than UF6 for laser uranic isotope separation.     

Some remarks on quasilinear wave equations with null condition in 3‐D

In this paper, we give an alternative proof to the global existence result, which is originally owing to the pioneering work of Klainerman and Christodoulou, for the Cauchy problem of quasilinear wave equations with null condition in three space dimensions. The proof can display the following three features simultaneously: the Lorentz boost operator is not employed in the generalized energy estimates; the generalized energy of the solution will be always small, which was first observed by Alinhac; and the initial data are not assumed to have a compact support. Copyright © 2016 John Wiley & Sons, Ltd.     

Metal-cation-based anion exchange membranes

Here we present the first metal-cation-based anion exchange membranes (AEMs), which were synthesized by copolymerization and cross-linking of a norbornene monomer functionalized with a water-soluble bis(terpyridine)ruthenium(II) complex and dicyclopentadiene. Each ruthenium complex has two associated counteranions, unlike most ammonium- and phosphonium-based membranes with single cation-anion pairs. The resulting AEMs show anion conductivities and mechanical properties comparable to those of traditional quaternary-ammonium-based AEMs as well as good alkaline stability and methanol tolerance. These results suggest that metal-cation-based polymers hold promise as a new class of materials for anion-conducting applications.     

Fractal analysis on human dynamics of library loans

In this paper, the fractal characteristic of human behaviors is investigated from the perspective of time series constructed with the amount of library loans. The values of the Hurst exponent and length of non-periodic cycle calculated through rescaled range analysis indicate that the time series of human behaviors and their sub-series are fractal with self-similarity and long-range dependence. Then the time series are converted into complex networks by the visibility algorithm. The topological properties of the networks such as scale-free property and small-world effect imply that there is a close relationship among the numbers of repetitious behaviors performed by people during certain periods of time. Our work implies that there is intrinsic regularity in the human collective repetitious behaviors. The conclusions may be helpful to develop some new approaches to investigate the fractal feature and mechanism of human dynamics, and provide some references for the management and forecast of human collective behaviors.     

RETRACTED ARTICLE: Microenvironment characterization for a novel biocompatible hybrid carbon-silicon material

The compatible carbon-silicon complex materials originated from precursor diglycerylsilane (DGS) and sugar-modified silane N-(3-triethoxysilylpropyl)gluconamide (GLS) have gained substantial popularity by demonstrating admirable properties to stabilize entrapped biomolecules. The microenvironment inside these materials, especially the distribution of sugar moieties inside the matrix, which is likely the most critical factor determining compatibility of these materials, still remains unclear. To deeply investigate the biocompatibility mechanism of these materials, we have adopted two different preparation routes for these materials by introducing GLS into the starting DGS sol stage, but things are different after the DGS gel is formed. A fluorescence probe rhodamine 6G is introduced herein in the DGS sol to monitor the distribution of GLS moieties, as well as the evolution of the microenvironment inside resulting materials. All in all, the findings demonstrated that the timing of GLS addition plays a critical role in controlling the evolution of the inner structure of materials, suggesting that this factor provides a promising route to tune the properties of the resulting materials. Supported by the National Natural Science Foundation of China (Grant No. 20876176), Scientific Research Foundation for the Returned Overseas Chinese Scholars by the State Education Ministry, Key Project of Chinese Ministry of Education (Grant No. 109100), Doctoral Project of Shandong Province (Grant No. 2008BS09013), Research Foundation of Key Laboratory of Carbon Materials, Institute of Coal Chemistry, CAS (Grant No. KFJJ0506), and Natural Science Foundation of Shandong Province (Grant No. Q2007B02)     

Electrodes surface-intercalated with powder catalysts: II. Microelectrodes surface-intercalated with powder catalysts

Microelectrode techniques were worked out for the study of electrocatalytic behaviors of powder catalysts. Ultra thin layer of fine catalyst powder was intercalated into the surface layer of soft conductive plastic sheet made from acetylene black and polytetrafluoroethylene (PTFE) binder. Microelectrodes of such construction have been successfully employed in the study of reversible and irreversible electrode reactions. Experimental results clearly indicated that microelectrode with ultra thin layer of surface-intercalated catalyst powder could serve as a powerful tool for the study of electrocatalytic behaviors of powder catalysts.     

Metabonomic profiling of liver metabolites by gas chromatography–mass spectrometry and its application to characterizing hyperlipidemia

The measurement of metabolites in tissues is of great importance in metabonomic research in the biomedical sciences, providing more relevant information than is available from systemic biofluids. The liver is the most important organ/tissue for most biochemical reactions, and the metabolites in the liver are of great interest to scientists. To develop an optimized extraction method and comprehensive profiling technique for liver metabolites, organic solvents of various compositions were designed using design of experiments to extract metabolites from the liver, and the metabolites were profiled by gas chromatography/time‐of‐flight mass spectrometry (GC/TOF‐MS). The resolved peak areas were processed by principle components analysis, partial least‐squares projections to latent structures, and discriminant analysis. The results suggest the highest extraction efficiency was for methanol–water, which maximized the majority of GC/TOF‐MS responses. The optimal solvent was applied to extract metabolites in liver of hyperlipidemia hamster and the control. The GC/TOF‐MS profiles of liver metabolites showed obvious differences between hyperlipidemic hamsters and controls. A comparison of liver and serum data from the same animals identified common biomarkers and presented complementary information. Our results suggest that liver metabonomics is a valuable technique and that the combined analysis of systematic biofluids and local tissues is meaningful and complementary, recovering more comprehensive metabonomic data than either analysis alone. Copyright © 2009 John Wiley & Sons, Ltd.     

亚硫酰氯阴极还原的半对数极化曲线

目前正在广泛研究的鲤/亚硫酰氯(Li/SOCl_2)电池是迄今为止比能量最高的一种新型化学电源。提高电池的性能和可靠性与电池反应的化学和电化学性质直接有关。但是,SOCl_2的还原过程相当复杂,对其反应机理迄今尚无明确的结论。由于SOCl_2还原时伴随着LiCl的沉积,当用常规电极测量时难以得到稳态极化曲线,因而至今未见报道SOCl_2还原反应的半对数极化曲线。微电极的单位表面上极限液相传质速度较高,且测量时较易得到稳态电流。因此,采用微电极方法可在一定程度上避开上述困难,研究SOCl_2还原反应的机理。     

Simultaneous separation of simulated radionuclides strontium and neodymium using in situ hydrotalcite synthesis

Aerosol collections were initiated at several locations by Pacific Northwest National Laboratory (PNNL) shortly after the Great East Japan earthquake of May 2011. Aerosol samples were transferred to laboratory high-resolution gamma spectrometers for analysis. Similar to treaty monitoring stations operating across the Northern hemisphere, iodine and other isotopes which could be volatilized at high temperature were detected. Though these locations are not far apart, they have significant variations with respect to water, mountain-range placement, and local topography. Variation in computed source terms will be shown to bound the variability of this approach to source estimation.