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81.
82.
Zheng-Ming Wang Noriko Yoshizawa Katsunori Kosuge Wendong Wang Geoffrey A. Ozin 《Adsorption》2014,20(2-3):267-274
Quiescent hydrothermal conditions were applied to synthesis of the sandwich nanocomposites of reduced graphite oxide (rGO) and periodic mesoporous silica (PMS) with vertically aligned mesochannels. It was found that the formation of the PMS–rGO–PMS sandwich structure is very sensitive to the surface and synthesis conditions. Although a higher temperature hydrothermal condition promotes reduction of GO and formation of bulky mesoporous nanoparticles, quiescent hydrothermal condition can serve as an alternative approach to obtain the unusual nanocomposites and slightly promote the structural stability of PMS on the surface of rGO. 相似文献
83.
The X-ray structure of H2T(3-Py)P·HgI2·C60, cocrystallized from a chlorobenzene/methanol solvent mixture containing 5,10,15,20- tetra(3-pyridyl)porphyrin, HgI2 and C60, has been determined. A new two dimensional arrangement of the tetra(3-pyridyl)porphyrin molecules joined by coordination to HgI2 is formed. These assemblies are connected by close C60-porphyrin π–π interactions leading to the alignment of the porphyrins into linear alternating fullerene porphyrin columns. The structure is compact with no significant cavities. 相似文献
84.
Hai‐Jing Nie Xialing Chen Chang‐Jiang Yao Prof. Dr. Yu‐Wu Zhong Prof. Dr. Geoffrey R. Hutchison Prof. Dr. Jiannian Yao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(45):14497-14509
Electron delocalization of new mixed‐valent (MV) systems with the aid of lateral metal chelation is reported. 2,2′‐Bipyridine (bpy) derivatives with one or two appended di‐p‐anisylamino groups on the 5,5′‐positions and a coordinated [Ru(bpy)2] (bpy=2,2′‐bipyridine), [Re(CO)3Cl], or [Ir(ppy)2] (ppy=2‐phenylpyridine) component were prepared. The single‐crystal molecular structure of the bis‐amine ligand without metal chelation is presented. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic techniques and DFT/TDDFT calculations. Compounds with two di‐p‐anisylamino groups were oxidized by a chemical or electrochemical method and monitored by near‐infrared (NIR) absorption spectral changes. Marcus–Hush analysis of the resulting intervalence charge‐transfer transitions indicated that electron coupling of these mixed‐valent systems is enhanced by metal chelation and that the iridium complex has the largest coupling. TDDFT calculations were employed to interpret the NIR transitions of these MV systems. 相似文献
85.
Magninos (neutral spin 1/2 fermions with mass 4–10 GeV and anomalous magnetic moment μ≈10−2) have been proposed as a solution to both the solar neutrino and dark matter problems. Direct detection of galactic halo magninos is possible via their coherent interaction with heavy nuclei. In this paper we have calculated the relevant non-relativistic cross section. We find a typical counting rate of about 100 events per day per kilogram of either a silicon or germanium detector. The magnetic moment of the magnino was needed in order to solve the solar neutrino problem. When scattering off of heavy nuclei, the charge radius r of the magnino is also relevant. 相似文献
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Derivatives of N-acetylgalactosamine and N-acetylglucosamine in which the 4-OH group could be selectively labelled have been prepared from a common precursor. 相似文献
89.
90.
Ison JR Virag TM Allen PD Hammond GR 《The Journal of the Acoustical Society of America》2002,112(1):238-246
Listeners asked to detect tones masked by noise hear frequent signals but miss infrequent probes, suggesting that they attend to spectral regions where they expect the signals to occur. The narrow detection pattern centered on the frequent target approximates that obtained in notched noise, indicating that attention is focused on the auditory filter. We measured attention bands in young and elderly listeners (n=5, 4; 20-25 and 62-82 years of age) for targets (800 or 1200 Hz) and infrequent probe signals (target +/-25-100 Hz) masked in wideband noise. We anticipated that their width would increase with age, as has been reported for auditory filters. A yes-no single-interval procedure provided detection probabilities and detection response speeds. Both measures showed near-linear declines with decreasing signal level, and graded decay functions as probe frequency deviated from the target frequency. Probes deviating from the target by 25 to 50 Hz were equivalent to a 2-dB reduction in signal level for both measures. The equivalent rectangular bandwidth (ERB) for detection approximated 11% of the signal frequency for each age group. Confidence intervals (95%) showed that the elderly ERB could be at most only about 20% larger than that of younger listeners. 相似文献