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991.
Superparamagnetic iron oxide nanoparticles with narrow size distributions were successfully prepared in large scale by a facile one‐pot synthetic method in the presence of hydrophilic polymers, such as polyethylene glycol diacid (HOOC‐PEG‐COOH) and poly(acrylic acid) (PAA). The as‐prepared products were investigated in detail by powder X‐ray diffraction (XRD), thermogravimetric analyses (TGA), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), and vibrating sample magnetometer (VSM). The interaction between polymers and iron oxide nanoparticles was investigated using Fourier transform infrared spectrometry (FT‐IR). The results show that polymers can be attached onto the surface of iron oxide nanoparticle by bridging coordination and monodentate fashion, respectively. The interaction affects iron oxide nanoparticle properties significantly, such as XRD diffraction intensity, hydrodynamic diameter, isoelectric point, and saturation magnetization. Furthermore, the results of in vitro experiments indicated that iron oxide‐PEG‐COOH nanoparticle is more cytotoxic than iron oxide‐PAA nanoparticle due to different coordinating modes. 相似文献
992.
A new copper and silver‐mediated cyanation of aryl iodides with DDQ as a cyanide source is achieved, providing nitriles with good yields. This new approach represents a safe method leading to aryl nitriles. 相似文献
993.
The anode materials Li4?xMgxTi5?xZrxO12 (x=0, 0.05, 0.1) were successfully synthesized by sol‐gel method using Ti(OC4H9)4, CH3COOLi·2H2O, MgCl2·6H2O and Zr(NO3)3·6H2O as raw materials. The crystalline structure, morphology and electrochemical properties of the as‐prepared materials were characterized by XRD, SEM, cyclic voltammograms (CV), electrochemical impedance spectroscopy (EIS) and charge‐discharge cycling tests. The results show that the lattice parameters of the Mg‐Zr doped samples are slightly larger than that of the pure Li4Ti5O12, and Mg‐Zr doping does not change the basic Li4Ti5O12 structure. The rate capability of Li4?xMgxTi5?xZrxO12 (x=0.05, 0.1) electrodes is significantly improved due to the expansile Li+ diffusion channel and reduced charge transfer resistance. In this study, Li3.95Mg0.05Ti4.95Zr0.05O12 represented a relatively good rate capability and cycling stability, after 400 cycles at 10 C, the discharge capacity retained as 134.74 mAh·g?1 with capacity retention close to 100%. The excellent rate capability and good cycling performance make Li3.95Mg0.05Ti4.95Zr0.05O12 a promising anode material in lithium‐ion batteries. 相似文献
994.
Hu Fu Chuang Ge Wei Cheng Caihui Luo Decai Zhang Li Yan Yun He Gang Yi 《Electroanalysis》2013,25(5):1223-1229
An electrochemical aptasensor was developed for sensitive and specific detection of thrombin by combining homogenous recognition strategy and gold nanoparticles (AuNPs) amplification. Streptavidin‐alkaline phosphatase was used as reporter molecule. Compared with the traditional hairpin aptasensor monitoring the distance of the redox molecule from the electrode surface, the proposed aptasensor successfully overcome the limitations of distance and improved the stability and high affinity of the aptamer hairpin through homogenous recognition, which enhanced the sensitivity and selectivity of the sensors effectively. Additionally, AuNPs were employed to increase the active area and conductivity of the electrode, thus, improving the sensitivity of the aptasensor. As a result, the designed thrombin detection sensor obtained a lower detection limit of 0.52 pM in buffer and 6.9 pM in blood serum. 相似文献
995.
996.
Qing-Zhong Li Wen-Ming Liu Ran Li Wen-Zuo Li Jian-Bo Cheng Bao-An Gong 《Structural chemistry》2013,24(1):25-31
The H2O···XCCNgF and H3N···XCCNgF (X = Cl and Br; Ng = Ar, Kr, and Xe) complexes have been studied with quantum chemical calculations at the MP2/aug-cc-pVTZ level. The results show that the inserted noble gas atom has an enhancing effect on the strength of halogen bond, and this enhancement is weakened with the increase of noble gas atomic number. The methyl and Li substituents in the electron donor strengthen the halogen bond. The interaction energy increases from ?3.75 kcal/mol in H3N–BrCCF complex to ?9.66 kcal/mol in H2LiN–BrCCArF complex. These complexes have been analyzed with atoms in molecules, natural bond orbital, molecular electrostatic potentials, and energy decomposition calculations. 相似文献
997.
The conventional strain energies of 1,2-dihydroazete, 2,3-dihydroazete, 1,2-dihydrophosphete, and 2,3-dihydrophosphete are determined within the isodesmic, homodesmotic, and hyperhomodesmotic models. Optimum equilibrium geometries, harmonic vibrational frequencies, and corresponding electronic energies and zero-point vibrational energies are computed for all pertinent molecular systems using SCF theory, second-order perturbation theory, and density functional theory and employing the correlation consistent basis sets cc-pVDZ, cc-pVTZ, and cc-pVQZ. Single-point fourth-order perturbation theory, CCSD, and CCSD(T) calculations employing the cc-pVTZ and the cc-pVQZ basis sets are computed using the MP2/cc-pVTZ and MP2/cc-pVQZ optimized geometries, respectfully, to ascertain the contribution of higher order correlation. Three DFT functionals, B3LYP, wB97XD, and M06-2X, are employed to determine whether they can yield results similar to those obtained at the CCSD(T) level. 相似文献
998.
Chen Ru-yu Cheng Leifeng 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):193-195
Abstract Cyclization of 1 with 2 yielded the title compound 3, which was transformed into the corresponding 1,3,2,4-diazadiphospholanes 4 and 5 by using DMSO or sulfur respectively. The addition reaction of 3 with butanedione gave 3,4-di-oxo-1-phenyl-2,5-diaza-6,9-dioxa-1λ5,3λ4-diphosphaspiro[4,4]nonane 6. The structures of 3, 4 and 5 were confirmed by elemental analysis, IR, NMR and GC-MS. Although 6 could not be isolated in pure form because of its rapid decomposition, the 31P NMR data indicated its existence. It was found that there were cis- and trans-isomers in 3, 4, 5 and 6. 相似文献
999.
1000.