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排序方式: 共有133条查询结果,搜索用时 31 毫秒
31.
S.B. Qadri T.M. Keller M. Laskoski C.A. Little P. Lubitz M.S. Osofsky H.R. Khan 《Applied Physics A: Materials Science & Processing》2007,86(3):391-394
Nanoparticles of Ru1-xFex (0≤x≤1) in a carbon matrix were synthesized over the entire composition range using organometallic precursors. For Fe concentrations
with x<0.70, a hexagonal close-packed phase was formed whereas a body-centered cubic phase was observed for x>0.70. The crystallite
sizes varied between 5–10 nm. In addition, multi-wall carbon nanotubes formed during the pyrolysis of the precursors. Increasing
superparamagnetic order was observed with increasing Fe content. 相似文献
32.
N.A. Mahadik S.B. Qadri M.V. Rao J.P. Yesinowski 《Applied Physics A: Materials Science & Processing》2007,86(1):67-71
Free-standing GaN films grown by hydride vapor phase epitaxy (HVPE) on c-plane sapphire have been studied for in-plane anisotropic strain. Lattice parameters are obtained from high-resolution X-ray diffraction data and the film quality is determined by measuring the rocking curves and by 71Ga nuclear magnetic resonance (NMR). The in-plane strain was determined using grazing incidence X-ray diffraction and conventional X-ray measurements. It is found that the in-plane lattice parameter varies with depth and has estimated surface strain anisotropy of 4.0791×10-3 up to a thickness of 0.3 μm. The 71Ga NMR experiments reveal different degrees of inhomogeneity amongst the three samples. This is shown by the appearance of an additional broad central-transition peak shifted to higher frequency by a Knight shift from conduction electrons in sample regions having high carrier concentrations. PACS 72.80.Ey; 61.10.-i; 61.72.Hh 相似文献
33.
A series of new symmetrical tetrazole-based carbazole derivatives starting from the initially generated 3,6-diformyl-N-alkylcarbazoles were successfully synthesized through a one-pot Ugi-azide reaction in moderate to high yields. Simplicity, easily accessible chemicals, mild reaction conditions, and fast separation of the products with the formation of bistetrazole-based carbazole derivatives in one step are some advantages of this method. The structure of the products was characterized and confirmed by using spectroscopic techniques such as 1H NMR, 13C NMR, FT-IR, and MS spectroscopy. 相似文献
34.
Abstract Electrical resistance measurements have been performed on samples of Hg1-xFexSe and Hg1-xMnxTe for × ≤ 0.30 as a function of pressure to 7.0 GPa. Both materials crystallize in the B3 structure at atmospheric pressure and room temperature and belong to the class of materials known as diluted magnetic semiconductors. At elevated pressures, HgTe undergoes a phase change from the B3 to B9 phase which is accompanied by an increase in the electrical resistivity of several orders of magnitude. The results reported here are that increasing × in both materials serves to increase the B3-B9 transition pressure. The implication being that partial replacement of the Hg-bonds by Fe-Se and Mn-Te, respectively, increases the stability range of the B3 phase 相似文献
35.
Shahnaz Rostamizadeh Hamid Estiri Mohammad Azad 《Journal of the Iranian Chemical Society》2016,13(7):1367-1374
36.
Seraj Faiza Kanwal Khan Khalid Mohammed Khan Ajmal Ali Muhammad Khalil Ruqaiya Ul-Haq Zaheer Hameed Shehryar Taha Muhammad Salar Uzma Perveen Shahnaz 《Molecular diversity》2021,25(1):143-157
Molecular Diversity - Novel ibuprofen derivatives 1–19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2–19 were synthesized and characterized by EI-MS, FAB-MS,... 相似文献
37.
38.
Mahboubeh Tasviri Shahnaz Ghasemi Hedayatollah Ghourchian Mohammad Reza Gholami 《Journal of Solid State Electrochemistry》2013,17(1):183-189
By combination of 1-ethyl-3-methyl immidazolium ethyl sulfate as a typical room temperature ionic liquid (IL) and graphene oxide (GO) nanosheets, a nanocomposite was introduced for improving the direct electrochemistry and electrocatalytic activity of glucose oxidase (GOx). The enzyme on the IL–GO-modified glassy carbon electrode exhibited a quasireversible cyclic voltammogram corresponding to the flavine adenine dinucleotide/FADH2 redox prosthetic group of GOx. At the scan rate of 100 mV?s?1, the enzyme showed a peak-to-peak potential separation of 82 mV and the formal potential of ?463 mV (vs Ag/AgCl in 0.1 M phosphate buffer solution, pH?7.0). The kinetic parameters of the charge transfer rate constant, the electron transfer coefficient, and the apparent Michaelis–Menten constant were calculated as 1.36 s?1 and 0.35 and 2.47 μM, respectively. When the modified electrode was examined as a biosensor for glucose determination, a linear range of 2.5–45 nM with detection limit of 0.175 nM (signal to noise?=?3) was obtained. The biosensor was stable for 2 months. 相似文献
39.
Khalid M. Khan Nida Ambreen Muhammad Taha Sobia A. Halim Zaheer-ul-Haq Shagufta Naureen Saima Rasheed Shahnaz Perveen Sajjad Ali Mohammad Iqbal Choudhary 《Journal of computer-aided molecular design》2014,28(5):577-585
Using structure-based virtual screening approach, a coumarin derivative (1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC50 values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC50 = 9.9–352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC50 values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent. 相似文献
40.
High performance liquid chromatography (HPLC) with a TSK-4000SW gel filtration column was used to compare envelope polypeptides from four strains of herpes simplex virus type 1 (HSV-1). The chromatographic profiles demonstrated polypeptide variability among three clinical strains and the wild-type F strain. Radioimmunoprecipitation of the HPLC fractions with polyclonal anti-HSV-1 followed by SDS-polyacrylamide gel electrophoresis (PAGE) of the immunoprecipitates revealed molecular weight differences of various polypeptides in fractions from the area containing major peaks. This HPLC method could prove useful for the analysis of polypeptide polymorphism in clinical isolates of HSV-1, as well as in other viruses. 相似文献