Papers by Nguyen Lam Quang Thoai
Định danh ấu trùng giai đoạn 3 Gnathostoma SP. thu thập trên cá lóc bông, lươn, ếch tại một số tỉnh phía Nam bằng phương pháp sinh học phân tử
Action des bromures de perfluoroalkylmagn�siums sur les ald�hydes a,��thyl�niques
J Fluorine Chem, 1975
Polymeres optiquement actifs. VI.: Absorption ultra‐violette et dispersion rotatoire de deux acides carboxyliques phénoliques optiquement actifs pris comme modèles de leurs polycondensats formophénoliques
Recueil des Travaux Chimiques des Pays-Bas, 2010
Journal of Mathematical Analysis and Applications, 1998
The basic idea of the reciprocity principle of Tikhonov is to construct, from a given problem, a ... more The basic idea of the reciprocity principle of Tikhonov is to construct, from a given problem, a reciprocal problem that has the same solution set as the original problem and some special structure one can employ to investigate theoretical properties as well as to develop solution methods. In this note, we prove the reciprocity principle for a pair of nonconvex optimization problems, from which some optimality conditions for d.c. optimization can be derived immediately.
Journal of Global Optimization, 2011
Two of the main approaches in multiple criteria optimization are optimization over the efficient ... more Two of the main approaches in multiple criteria optimization are optimization over the efficient set and utility function program. These are nonconvex optimization problems in which local optima can be different from global optima. Existing global optimization methods for solving such problems can only work well for problems of moderate dimensions. In this article, we propose some ways to reduce the number of criteria and the dimension of a linear multiple criteria optimization problem. By the concept of so-called representative and extreme criteria, which is motivated by the concept of redundant (or nonessential) objective functions of Gal and Leberling, we can reduce the number of criteria without altering the set of efficient solutions. Furthermore, by using linear independent criteria, the linear multiple criteria optimization problem under consideration can be transformed into an equivalent linear multiple criteria optimization problem in the space of linear independent criteria. This equivalence is understood in a sense that efficient solutions of each problem can be derived from efficient solutions of the other by some affine transformation. As a result, such criteria and dimension reduction techniques could help to increase the efficiency of existing algorithms and to develop new methods for handling global optimization problems arisen from multiple objective optimization.
Journal of Fluorine Chemistry, 1992
Although variously fluorinated esters of acrylic acid have received important applications as mon... more Although variously fluorinated esters of acrylic acid have received important applications as monomers in the polymer field, the chemistry of genuine fluoroacrylic acids and esters, i.e. bearing fluorine atoms at the (Y and/or p positions, has received scarce attention, except for the promising cu-fluoroacrylates. This is mainly owing to synthesis problems. Two routes to some (previously unknown) /3-fluoroacrylic esters have already been reported [H. Molines and C.
Journal of Fluorine Chemistry, 1975
Rep le 5 avril 1974) Resume Les magnesiens perfluores C,F,, + r MgBr (n = 2, 6, 8) reagissent sur... more Rep le 5 avril 1974) Resume Les magnesiens perfluores C,F,, + r MgBr (n = 2, 6, 8) reagissent sur les aldehydes a$ ethyleniques uniquement en 1,2 pour donner les alcools allyliques. La presence de CuCl ne permet pas d'etendre la reaction au pole 0 du systeme conjugue C=C-C=O. Une partie des magnesiens se decomposent en truns-RFCF=CFBr et trans-RFCF=CFI. Ni une dissociation en Rg MgX-, ni celle en RF ne permettent pour le moment d'expliquer la decomposition thermique des magnesiens. Summary Perfluoroalkylmagnesium bromide, C,F,, + iMgBr (n = 2, 6, 8), reacts with cw$-unsaturated aldehydes to give allylic alcohols as the sole products. No attack on the B-carbon atom of the carbonyl was detected, even when the reaction was carried out in the presence of CuCl. Part of the Grignard reagent decomposes to trans-RFCF=CFBr and trans-R,CF=CFI. Neither a mechanism involving dissociation into Rg MgX-nor the formation of a carbene intermediate is capable of explaining the thermal decomposition of the Grignard reagent.
Journal of Colloid and Interface Science, 1977
European Journal of Operational Research, 2000
One of the most important and interesting approaches in multiple criteria optimization is the pro... more One of the most important and interesting approaches in multiple criteria optimization is the problem of optimizing some function over the set of ecient solutions. This is a very dicult multiextremal global optimization problem, even for the case that the underlying multiple criteria program is linear and the function to be optimized over the ecient set is linear as well. In this article, we consider the problem of maximizing a special function over the ecient set of a multiple criteria concave maximization problem under the assumption that the objective function is a nondecreasing composite quasiconvex function of the concave criteria. We show that this problem can be formulated as a special global optimization problem in the outcome space. An algorithm of the outer approximation type is proposed for solving the resulting problem. Preliminary computational experiments show that this algorithm can work well for problems with a small number of criteria (less than 8), while the dimension of the decision space can be fairly large.
Etude conformationnelle des alcényl phénylcétones par spectrographies infrarouge, ultraviolette et par l'utilisation de l'effet Overhauser nucléaire et de complexe de lanthanide Eu(dpm)3 en résonance magnétique nucléaire
Canadian Journal of Chemistry, 1974
By the use of i.r., u.v. and n.m.r. (n.O.e. and europium chelates) we have shown that a series of... more By the use of i.r., u.v. and n.m.r. (n.O.e. and europium chelates) we have shown that a series of phenyl ketones (R1R2C=CR3—CO—C6H5) exist within the s-cis conformation probably because of the steric bulk of the benzene ring. When these ketones have an alkyl substituent (R3=Me, Et) on the carbon atom α to the carbonyl group, the molecule is no longer planar. The molecular torsion in this case is not around the CO—C6H5, bond but rather at the CO—C= bond. The resulting dihedral angle is about 65°. We propose a tabular method which together with the use of Eu(dpm)3 allows rapid determination of the preferred conformation of non rigid α,β-unsaturated ketones and in the case of non-planar conformations allows the estimation of the dihedral angle between the C=C and C=O chromophores. [Journal translation]
Nghiên cứu một số đặc điểm sinh học của 3 chủng nấm linh chi được phân lập từ tự nhiên
Can Tho University Journal of Science, 2020
Uploads
Papers by Nguyen Lam Quang Thoai