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281.
Tran Duc Thiep Truong Thi An Nguyen The Vinh Phan Viet Cuong A. G. Belov O. D. Maslov Trinh Thi Thu My 《Physics of Particles and Nuclei Letters》2006,3(4):223-228
We have carried out a study on the isomeric ratio in the 197Au(γ, n)196m,g
Au photonuclear reaction in a giant dipole resonance region with bremsstrahlungs produced by electron accelerator Microtron
MT-25 of the Flerov Laboratory of Nuclear Reactions, JINR. The isomeric ratio has been determined from a series of gamma spectra
measured with a high-energy-resolution gamma spectrometric system consisting of an HPGe detector and a multichannel analyzer.
The results have been discussed, compared with those of other authors, as well as considered by the statistical model supposed
by Huizenga and Vandenbosch.
The text was submitted by the authors in English. 相似文献
282.
Ho Duc Cuong Thanh Thi Thu Thuy Tran Thu Huong Bui Minh Ly Tran Thi Thanh Van 《Natural product research》2015,29(5):411-415
The aim of this study is to elucidate the structure and investigate the hypolipidaemic activity of a fucoidan extracted from brown seaweed Sargassum henslowianum collected at Hai Van–Son Cha peninsula, Hue province, Vietnam by using tandem electrospray ionisation mass spectrometry. The results demonstrated that the fucoidan has α(1 → 3)-linked l-fucopyranose backbone and sulphate groups occupied mostly at C-2, C-4 and sometimes at C-3 position of fucose residues. The results of in vivo bioactivity examination revealed that the fucoidan in the dose of 100 mg/kgP/day by oral administration helped decrease cholesterol, triglyceride and LDL-cholesterol levels on obese mice. 相似文献
283.
284.
285.
Pierre Thuéry;Jack Harrowfield; 《欧洲无机化学杂志》2018,2018(40):4465-4471
Three heterometallic complexes including uranyl and either CoIII or MnII cations were crystallized under hydrothermal conditions. Complexes [Co(bipy)3]2[UO2(NO3)4]2[(UO2)2(NO3)4(OH)2] (1) and [UO2(NO3)2Co(bipy)2(OH)2]·NO3·H2O (2) (bipy = 2,2′-bipyridine) were obtained from the same solution. UO22+ and CoIII are part of separate anions and cations, respectively, in complex 1, the uranyl ion being present in both a mononuclear dianion with two chelating and two monodentate nitrates in cis positions, and in a dinuclear, bis-hydroxo-bridged dianion. In contrast, both metal cations are part of a monocationic heterometallic bis-hydroxo-bridged complex in 2, UO22+ retaining two nitrate and CoIII two bipy ligands. This is the third example only of a hydroxo-bridged heterometallic uranyl complex, and the first to involve CoIII. The complex [(UO2)6Mn(O)4(OH)6(H2O)4]·5H2O (3), synthesized in the absence of any added ligand, crystallizes as a three-dimensional framework in which anionic uranyl oxyhydroxide layers with the α-U3O8-type polyhedral arrangement are connected to one another by Mn(H2O)42+ cations axially bound to two uranyl oxo atoms. These very simple systems thus display a large range of possible intermetallic associations, that involving bis-oxo-bonding to uranyl enabling formation of a framework through pillaring of sheets. 相似文献
286.
Kristina Hanauer;Minh Thu Pham;Christoph Förster;Katja Heinze; 《欧洲无机化学杂志》2017,2017(2):433-445
Conformations and (dis)assembly processes of ureas and thioureas are of fundamental importance in supramolecular chemistry, anion binding, or crystal engineering, both in solution and in the solid state. For sensing and switching processes a redox-active unit, such as the ferrocene/ferrocenium couple, is especially suitable. Here, self-assembly processes of redox-active ferrocenyl(thio)ureas FcNHC(X)NHR [X = O, R = Fc (1), Ph (2), 1-naphthyl (3), Me (4), Et (5); X = S, R = Fc (6), 1-anthracenyl (7)] through hydrogen bonds – both in the solid state and in THF and CH2Cl2 solution – are reported. Special emphasis is placed on the impact of nonclassical intramolecular NH···Fe hydrogen bonds in these organometallic systems [these are absent in conventional organic (thio)ureas] on conformation and assembly. Furthermore, conformational switching and disassembly of 1–6 is induced by oxidation of 1–6 to the corresponding ferrocenium cations 1+–6+ (redox switch). 相似文献
287.
288.
The first crystal structures of a p-tert-butyltetrahomodioxacalix[6]arene comprising two tri-phenolic subunits separated by two ether bridges and two of its complexes with uranyl ions are reported. The doubly deprotonated macrocycle assumes a much elongated, cone-like conformation including two organic species. Two binuclear uranyl complexes are described. In both, each cation is bound to the three phenoxide oxygen atoms of a tri-phenolic subunit and to a central, bridging, carbonate or carbamate ion. The formation of the latter ions from the amines used as bases is discussed. 相似文献
289.
Zin Thu Win ;Boping Tian 《Discrete and continuous dynamical systems》2023,28(5):2994-3013
We are interested in modeling the influence of random fluctuations on population systems. In this paper, we consider the population dynamics of jellyfish stochastic differential equation by introducing the random perturbation. Firstly, we provide the sufficient criteria to study the existence and uniqueness of non-negative solution. We prove that population will be permanence and persistence in mean when the noise is relatively small as well as it is discussed that the population may become extinct with probability one when the noise is too large. Then we show that the system has a stationary distribution under sufficient conditions using Hasminskii's methods and Lyapunov function. Finally, numerical simulations are performed to verify the results attained in this paper. 相似文献
290.
Novokshonov V. V. Xuan Nguyen Thi Thu Shaglaeva N. S. 《Russian Journal of Organic Chemistry》2019,55(10):1616-1617
Russian Journal of Organic Chemistry - An improved procedure has been proposed for the synthesis of 6I-O-(4-methylbenzenesulfonyl)-β-cyclodextrin by reaction of β-cyclodextrin with... 相似文献