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1.
Ovshinsky SR Young RT Allred DD DeMaggio G Van der Leeden GA 《Physical review letters》1987,58(24):2579-2581
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Infrared spectra were obtained for the series of 2,X-dimethylheptanes (X = 2,3,4,5,6) and were interpreted with the aid of normal coordinate calculations. 2,2-DMH exists as two conformers, with the Cs conformer being the only one present in the crystalline solid. 2,3-DMH exists in at least three conformations, all of C1 symmetry. Ambiguities in spectral data indicate that more conformations are present. Two C1 conformations of 2,4-DMH were shown to be present, but an unassigned band may indicate the presence of a third conformer. The presence of at least four conformers, all of C1 symmetry, was shown to be necessary to explain the spectrum of 2,5-DMH. Finally, 2,6-DMH was shown to exist as three conformers, of symmetries Cs, C2, and C1. Vibrational assignments were made for all the probable conformers of all five compounds. 相似文献
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Infrared and Raman spectra have been obtained for 1,4-dibromopentane and interpreted with the aid of normal coordinate calculations. It is concluded that all six conformers resulting from rotation about the C1-C2 and C3-C4 bonds probably exist in the neat liquid and amorphous solid, and that the compound crystallizes in the PHSHH conformer that has the two bromine atoms on opposite sides of the plane of carbon atoms. The compound therefore behaves like 1,3-dibromopropane and 1,4-dibromobutane. 相似文献
6.
种植沙生植物--沙棘改善内蒙古地区生态环境 总被引:2,自引:0,他引:2
结合内蒙古地区现状,对沙棘的生物学和生态学特性、沙棘属植物化学成分和微量元素及种植沙生植物——沙棘的重要性和必要性进行了详细的研究和探讨。研究表明,沙棘属植物具有极强的生态适应性并富含多种营养成分和生物活性物质,并以耐干旱、耐瘠薄、萌蘖及固氮能力强等特点被称为治理非宜林地水土流失、改善生态环境的先锋树种。种植沙棘是治理内蒙古脆弱生态环境最经济、最有效的措施,是贫瘠的不毛之地发展经济、增加收入的经济树种。另外.种植沙棘的技术简便,容易掌握,投资少,见效快。 相似文献
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Infrared and Raman spectra have been obtained for benzyl fluoride and a vibrational assignment has been made. The spectra indicate the presence of a large number of conformers that differ only in the orientation of the C-F bond, as a result of free or nearly free internal rotation. 相似文献
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以内蒙古地区沙棘果实为原料,研究了提取黄色素的工艺条件,同时对该色素的性质进行了初步探讨。结果表明,以95%的乙醇溶液作浸提剂,提取的黄色素浓度最高,工艺流程简单易行,且无毒,无污染。对提取的黄色素进行的性质试验表明,沙棘黄色素对光、热具有较好的稳定性,适用于酸性或弱碱性的食品中,葡萄糖、氧化剂(H2O2)、还原剂(Na2SO3)等食品添加剂均无明显影响以上结果为这种优良天然色素的开发与应用提供了参考。 相似文献
9.
G.A. Crowder 《Molecular physics》2013,111(4):707-715
Normal coordinate calculations were carried out for fluoro-, chloro-, bromo- and iodoacetonitrile, using a seventeen-parameter valence force field. Most of the force constants have different values in the four halides that change in a regular manner. The a″ vibrations are essentially pure, but there is considerable mixing of normal modes in the a′ species. The difference in previous vibrational assignments is resolved but the bands assigned to the C-C-Br and C-C-I bends were found to be mainly C-Br and C-I stretching vibrations. Transferability of the force constants obtained for the CH2Cl group seems quite good. 相似文献
10.
Tvaskis V Christy ME Arrington J Asaturyan R Baker OK Blok HP Bosted P Boswell M Bruell A Cochran A Cole L Crowder J Dunne J Ent R Fenker HC Filippone BW Garrow K Gasparian A Gomez J Jackson HE Keppel CE Kinney E Lapikás L Liang Y Lorenzon W Lung A Mack DJ Martin JW McIlhany K Meekins D Milner RG Mitchell JH Mkrtchyan H Moreland B Nazaryan V Niculescu I Opper A Piercey RB Potterveld DH Rose B Sato Y Seo W Smith G Spurlock K van der Steenhoven G Stepanyan S Tadevosian V Uzzle A Vulcan WF Wood SA 《Physical review letters》2007,98(14):142301
We report on a study of the longitudinal to transverse cross section ratio, R=sigmaL/sigmaT, at low values of x and Q2, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06相似文献