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排序方式: 共有9903条查询结果,搜索用时 31 毫秒
991.
Multi-wall carbon nanotubes and polyaniline composites were synthesized via a simple hydrothermal reaction, and the as-made composites were successfully applied in the analysis of small molecular-weight metabolites as a novel matrix by matrix assisted laser desorption/ionization mass spectrometry. 相似文献
992.
Zhu C Meng G Huang Q Zhang Z Xu Q Liu G Huang Z Chu Z 《Chemical communications (Cambridge, England)》2011,47(9):2709-2711
Large-scale Ag nanosheet-assembled micro-hemispheres, with sufficient hot spots on their surfaces, have been achieved on an indium tin oxide substrate via electrodeposition. Surface-enhanced Raman scattering (SERS) measurements demonstrate that the Ag nanosheet-assembled micro-hemispheres can serve as sensitive and reproducible SERS substrates. 相似文献
993.
A facile synthesis of potential acetylcholinesterase (AChE) inhibitors, the tacrine analogues 3a-p, has been accomplished by direct cyclocondensation of 1-aryl-4-cyano-5-aminopyrazole with β-ketoesters using tin(IV) chloride as catalyst. The structures of all the compounds have been confirmed by IR, 1H- and 13C-NMR. 相似文献
994.
Zhang A Fang Y Li X Meng J Wang H Li H Zhang Z Guo Z 《Molecules (Basel, Switzerland)》2011,16(4):2846-2861
The concentration of trans-resveratrol in 165 grape cane samples from three major grape production regions and four large distribution centers of Chinese wild Vitis species were determined by reversed-phase high-performance liquid chromatography (HPLC). Among the different genotype groups and purpose of uses, cultivars of V. vinifera had much higher amounts of trans-resveratrol than did the cultivars of both V. labrusca or V. labrusca and V. vinifera hybrids, and within the V. vinifera species, significantly higher amounts of trans-resveratrol were found in wine grapes compared to table ones. No significant differences were observed between V. labrusca and its hybrids from crosses with V. vinifera, and between red cultivars and white ones (P < 0.05 or P < 0.01). The contents of trans-resveratrol, as a normal constituent occurring in grape canes, in Chinese wild species of V. amurensis, V. pentagona, and V. davidii from their native habitats were also relatively high. 相似文献
995.
Chen-Zhong Yao Hui-Xuan Ma Xi-Sheng Zhang Li-Xin Meng Li-Ping Zhao Ling Tai Yu-Chun Wang Qiao-Juan Gong Ye-Xiang Tong 《Journal of Solid State Electrochemistry》2011,15(6):1193-1199
Magnetic dendrites of Co
x
Pb1−x
were fabricated through potentiostatic electrochemical deposition on Cu substrates in boric acid solution at room temperature.
The as-deposited dendrites were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron
microscopy (TEM), electrodeposition (ED), and energy dispersive X-ray spectroscopy (EDS). SEM results indicate that the Co
x
Pb1−x
dendrites are highly symmetrical in structures. The diameters of the branches are about 50 ~ 200 nm, and the backbones are
continuous with lengths up to about 10 μm. XRD patterns show that the as-deposited dendrites are solid solutions. The annealing
treatment can result in the recrystallization of these metastable alloys into two separate phases. TEM, ED, and EDS results
also reveal that the backbones and the branches of the dendrites are composed of different amounts of cobalt. Magnetic measurements
confirm that the as-deposited Co
x
Pb1−x
dendrites have a softly ferromagnetic behavior, and a small coercive force (about 80 Oe). Also the saturation magnetizations
of the Co
x
Pb1−x
dendrites decrease rapidly with the temperature increasing. 相似文献
996.
Qingyong Meng Hai-Bo Chang Ming-Bao Huang Hua Dong 《Theoretical chemistry accounts》2011,128(3):359-365
The N-loss predissociation mechanisms of the A 2Σ+ (2 2
A′) state of N2O+ to the first and second dissociation limits were studied in the C
s symmetry. The potential energy curves (PECs) and minimum energy crossing points (MECPs) for the C
s states of N2O+ were calculated at the CAS levels. On the basis of our CAS calculation results (CASPT2 energetic results and CASSCF spin
orbit couplings), we suggest two processes for N-loss predissociation mechanisms of A 2Σ+ (2 2
A′) to the first and second limits. The first two steps in the two processes are the same: A 2Σ+ passes through the 2 2
A′/1 4
A″ MECP and then reaches the 1 4
A″ (1 4Σ−) PEC. The 2 2
A′/1 4
A″ MECP has a bent geometry and is slightly higher in energy than the transition state along the 1 4
A″ PEC. Our mechanisms are different from the previously suggested mechanisms (via 1 4Π). 相似文献
997.
Yuan Shang Qikai Li Lingyi Meng Dong Wang Zhigang Shuai 《Theoretical chemistry accounts》2011,129(3-5):291-301
We present recent progresses on applying the theoretical models and computational tools in assessing the performance of organic solar cells, especially the bulk heterojunction solar cells. Both the continuum device model and the dynamic Monte Carlo model are developed to investigate the photocurrent-voltage characteristics based on the exciton and charge carrier dynamics. Insights into key factors influencing the organic photovoltaic performances have been gained from these studies. 相似文献
998.
999.
1000.