排序方式: 共有11条查询结果,搜索用时 15 毫秒
1.
Moiz Ahmad Yinan Liu Zachary W. Slavens Russell Low Elmar Merkle Ken-Pin Hwang Anthony Vu Jingfei Ma 《Magnetic resonance imaging》2010
Sampling water and fat signals symmetrically (i.e., at 0° and 180° relative phase angles) in a dual-echo Dixon technique offers high intrinsic tolerance to phase fluctuations in postprocessing and maximum signal-to-noise performance for the separated water and fat images. However, identification of which image is water and which image is fat after their separation is not possible based on the phase information alone. In this work, we proposed a semiempirical automatic image identification method that is based on the intrinsic asymmetry between the water and fat chemical shift spectra. Specifically, the approximately bimodal feature of the fat spectra and the observation that most in vivo tissues are either predominantly water or predominantly fat are used to construct a spectrum-based algorithm. Additional refinement is accomplished by considering the spatial distribution of the tissues that may have a coexistence of water and fat. The final improved algorithm was tested on a total of 131 three-dimensional patient datasets collected from different scanners and found to yield correct water and fat identification in all datasets. 相似文献
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N. S. Prostakov Sipeu Simo Moiz V. P. Zvolinskii G. I. Sherenkova 《Chemistry of Heterocyclic Compounds》1970,6(6):719-721
2-Benzyl-3,6-dimethyl-4-phenylpyridine has been obtained from 2,5-dimethyl-4-phenyl-pyridine by the Ladenburg—Chichibabin reaction. The compounds formed in its oxidation have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinii, Vol. 6, No. 6, pp. 779–781, June, 1970. 相似文献
3.
Parvej Ali Seema Srivastava Moiz Ahmad 《Journal of Macromolecular Science: Physics》2014,53(7):1305-1317
Using the Urey–Bradley force field and Wilson's GF matrix method as modified by Higgs, normal modes of vibration and their dispersions in poly(3-methylthiophene) have been obtained. They provide a detailed interpretation of its I.R. and Raman spectra. Characteristic features of the dispersion curves, such as regions of high density-of-states, repulsion, and character mixing of dispersive modes, are discussed. Predictive values of the heat capacity as a function of temperature have been calculated. 相似文献
4.
Khasan Sanginovich Karimov Muhammad Tariq Saee Fazal Ahmad Khali Syed Abdul Moiz 《中国物理 B》2011,20(4):40601-040601
This paper investigates the properties of displacement sensors based on polyaniline (PANI) films. About 1 wt% of PANI micropowder is mixed and stirred in a solution of 90 wt% water and 10 wt% alcohol at room temperature. The films of PANI are deposited from solution by drop-casting on Ag electrodes,which are preliminary deposited on glass substrates. The thicknesses of the PANI films are in the range of 20 μm-80 μm. A displacement sensor with polyaniline film as an active material is designed and fabricated. The investigations showed that,on average,the AC resistance of the sensor decreases by 2 times and the capacitance accordingly increases by 1.6 times as the displacement changes in the range of 0 mm-0.5 mm. The polyaniline is the only active material of the displacement sensor. The resistance and capacitance of the PANI changes under the pressure of spring and elastic rubber,and this pressure is created by the downward movement of the micrometer. 相似文献
5.
Daniel D. Caspi Russell D. Cink Dean Clyne Moiz Diwan Kenneth M. Engstrom Timothy Grieme Jianzhang Mei Robert W. Miller Clifford Mitchell José G. Napolitano Nandkishor Nere Matthew M. Ravn Ahmad Sheikh Seble Wagaw Hongqiang Zhang 《Tetrahedron》2019,75(32):4271-4286
ABT-450 (8), a potent hepatitis C (HCV) NS3/4A protease inhibitor, was approved as part of AbbVie's first generation HCV treatment for the United States in December 2014. A series of process optimizations were developed over six years to support the program starting with recycling of a previous protease inhibitor candidate through route development and final process. This discussion will focus on optimization of the final six steps starting from dipeptide 12 and amino acid 13 and highlights the use of a large scale ring closing metathesis (RCM), reactive crystallizations for isolation of intermediates, and detailed process understanding of the final sulfonamide coupling. The process provides ABT-450 (8) in 72% overall yield for the final 6 steps. 相似文献
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Arsheen Moiz M. Aleem Ahmed Naheed Kausar Kamran Ahmed Munnaza Sohail 《Journal of Saudi Chemical Society》2010,14(1):69-76
Aqueous extract of natural dye, tea was dyed on the wool fabric with dark brown for 2% and 5% shade. The tea containing tannins as the main colorant species to produce different shade with different mordant salts. The mordant salts Alum, CuSO4, FeSO4, ZnSO4, Na2SO4, and MgSO4 were used to dye fabric using three different dyeing methods: pre-mordanting, meta-mordanting and post-mordanting. The color of the fabric was investigated on Data Color matching system in terms of K/S and CIE Lab-color difference values. The post-mordanting method gave the great depth of shade of natural dye tea with 2% and 5% shade, it also give good light fastness and wash fastness properties. Copper was found as a good mordant to achieve the best results with transition metal ions effect. Deep shades (K/S = 17.50) were obtained for original sample of 5% with color difference ΔE value is 0.17, as compare to 2% original sample of tea of light brown shades (K/S = 10.50) with color difference ΔE value is 0.50 under maintained temperature at 85 °C for 35 min of dyeing. 相似文献
8.
N. S. Prostakov Sipeu Simo Moiz V. P. Zvolinskii V. V. Dorogov 《Chemistry of Heterocyclic Compounds》1972,8(1):85-88
New substituted 4-phenyl-2-benzyl- and 2,4-dibenzylpyridines were obtained, and some of their transformations were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 91–94, January, 1972. 相似文献
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N. S. Prostakov Sipeu Simo Moiz A. T. Soldatenkov V. P. Zvolinskii G. I. Cherenkova 《Chemistry of Heterocyclic Compounds》1971,7(10):1305-1309
The possibility of obtaining 3-methyl-2-azafluorene by dehydrocyclization of 2,5-dimethyl-4-phenylpyridine at 500–750° in the absence of a catalyst was examined. This azafluorene was condensed with aromatic aldehydes. Several transformations of the geometrical isomers of 3-methyl-9-benzylidene-2-azafluorene and its analogs were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1398–1402, October, 1971. 相似文献