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51.
Collision-induced decompositions (CIDs) of the [M + H]+, [M + Li]+, [M + Na]+, [M + K]+ and [M + Ag]+ ions of some methyl-6-deoxy-6-bromo-α-D-glucopyranoside derivatives are discussed. Elimination of MeOH resulting in the glycosidyl cation is the predominant reaction of the [M + H]+ ion. This process is completely suppressed during CID of the metal-cationized species, which, surprisingly, show elimination of the added metal in the form of RCOO-metal and metal bromide in the case of the ester derivatives. These reactions appear to be assisted by neighbouring group participation. Because of the proximity of the C(3)-oxygen with C(6), the benzyl ether derivative is characterized by the loss of PhCH2Br from the [M + metal]+ ion.  相似文献   
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An easy access to enantiopure isochromans through cross alkyne trimerization of a glucose derived dialkyne was developed. One of the synthesized isochromans was converted into a novel tricyclic nucleoside by simple transformations.  相似文献   
53.
Clover detector has been used as a Compton polarimeter to measure the linear polarization of γ-rays produced in heavy ion fusion reaction. The polarization sensitivity of the clover detector has been measured over γ-ray energies ranging from 386 to 1368 ke V. The E1 multipolarity of the 1117 keV transition in 99Rh has been established using this polarimeter. This has resulted in the assignment of negative parity to the band head at 3710 keV in 99Rh.  相似文献   
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Industrial waste locks are used as raw materials to reduce harmful effects on the environment and improve environmental performance. Marble clay powder can be used as a filling aid and can fill voids in concrete structures. This article will show you how to use a maximum natural sand alternative in concrete with marble powder and quarry dust. The challenge of the 21st century is to change to a new form that can support the natural system. This necessitates a radical rethinking of how to give the community infrastructure and housing. Making a concerted effort to develop novel, innovative, and alternative construction materials may be necessary. Jungles of concrete around cause's impact on the Environment and it would result in climate change. Mankind must avoid the use of things that are detrimental to the environment. So in this paper, it is decided to address the issue by adopting the use of the green concrete concept which is environmentally friendly. Green concrete is concrete made up using industrial wastes such as marble powder, quarry dust, wood ash, paper pulp, etc. Green concrete, which is capable of sustainable development, helps to reduce the consumption of natural resources, energy use, and environmental pollution. Green concrete is more cost-effective than ordinary concrete and reduces the cost of resultant concrete by 14%–20%. It is also observed that the alkali-aggregate reaction and sulfate attack resistance of concrete are both significantly improved. Green concrete is a useful tool for lowering environmental pollution and enhancing concrete's resistance to harsh conditions. All stages of infrastructure construction and rehabilitation will follow this trend of using new cement and techniques. Green concrete's adaptability and its performance derivatives will meet a variety of future needs.  相似文献   
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