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991.
Shoichi Nakata Jose Brisson 《Journal of polymer science. Part A, Polymer chemistry》1997,35(12):2379-2386
Copolyamides based on poly(m-phenylene isophthalamide) and poly-(p-phenylene terephthalamide), to which 1,6-diaminohexane units were regularly inserted every 3 or 5 phenylene monomer units, were synthesized. The copolymers were obtained by condensation of individually prepared diamino- and dicarboxylic-building blocks via the Yamazaki–;Higashi reaction. Solubility of the copolyamides are discussed in relation with the structure. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2379–2386, 1997 相似文献
992.
Carboalumination of alkynes in the presence of catalytic Cp2ZrCl2 and H2O affords vinyl‐alane intermediates, which serve as nucleophiles in the subsequent addition to enantiomerically enriched (tert‐butyl)‐ and (para‐tolyl)sulfinimines. This new in situ protocol produces two new C C bonds. Chiral allylic sulfinamides are obtained in high diastereoselectivity and in good yield. Cleavage of the chiral auxiliary leads to synthetically useful allylic amine building blocks, and facile oxidative degradation of the alkene moiety can be used as an approach toward amino acid derivatives and for assignment of absolute configuration. 相似文献
993.
994.
H. Oppermann H. Dao Quoc M. Zhang‐Preße P. Schmidt B. A. Popovkin P. S. Berdonosov V. A. Dolgikh 《无机化学与普通化学杂志》2002,628(4):891-895
Investigations on the System SmOCl/SeO2 The existence of three ternary phases SmSeO3Cl, SmSe2−O5Cl, and SmSe3O7Cl is shown on the quasibinary line SmOClSeO2. The phase barogram and the phase diagram are determined by total pressure measurements and DTA, respectively. SmSe3O7Cl melts peritectical at 340 ± 10 °C, SmSe2O5Cl melts peritectical at 560 ± 10 °C while SmSeO3Cl shows no thermal effects up to 900 °C The data of enthalpies and entropies of the phases are evaluated from the total pressure measurements (Data see „Inhaltsübersicht”︁) 相似文献
995.
Linda Leme Mihaela Gulea Monique Saquet Serge Masson Noël Collignon 《Heteroatom Chemistry》1999,10(4):281-289
New variously substituted 1‐dimethylamino or 1‐methylthio but‐3‐enylidene‐bis‐phosphonates have been prepared from readily availableα‐dimethylamino or α‐methylthio methylene‐bis‐phosphonates by postulated [2,3]‐Wittig rearrangements of the corresponding N‐ or S‐allylic intermediate ylides. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 281–289, 1999 相似文献
996.
997.
D. A. Jackson J. T. Koberstein R. A. Weiss 《Journal of Polymer Science.Polymer Physics》1999,37(21):3141-3150
The crystallization, melting, and dissolution behavior of zinc stearate (ZnSt) in ZnSt-filled sulfonated poly(ethylene-co-propylene-co-ethylidene norbornene) (SEPDM) ionomers was studied by synchrotron small-angle X-ray scattering (SAXS). The melting temperature of ZnSt in the ionomer was considerably lower than in the pure state, which was consistent with the existence of very small ZnSt crystalline domains and a specific interaction between the metal sulfonate groups of the SEPDM and the metal carboxylate groups of ZnSt. Temperature-resolved SAXS showed that, on melting, some or all of the ZnSt rapidly dissolved into the ionomer. Ionic aggregates in the neat ionomer persisted up to 300°C. Microphase separation was also observed at elevated temperatures for the ZnSt-filled ionomers, but the composition of the microdomains was believed to be quite different than that of the microdomains in the neat SEPDM. The time and temperature dependence of the ZnSt crystallization in the filled ionomers was characterized by time-resolved SAXS experiments following a temperature quench from the melt. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 3141–3150, 1999 相似文献
998.
Radu Custelcean James E. Jackson 《Angewandte Chemie (International ed. in English)》1999,38(11):1661-1663
Topochemical assembly of a covalent material can be achieved with the complex LiBH4⋅TEA (TEA=triethanolamine; section of structure shown), a dihydrogen-bonded system which has very short H⋅⋅⋅H contacts and high solid-state reactivity due to acidity enhancement in the OH groups by Li+ ion complexation. 相似文献
999.
This paper is devoted to the mathematical justification of the Bending-Gradient theory which is considered as the extension of the Reissner-Mindlin theory (or the First Order Shear Deformation Theory) to heterogeneous plates. In order to rigorously assess the well-posedness of the Bending-Gradient problems, we first assume that the compliance tensor related to the generalized shear force is positive definite. We define the functional spaces to which the variables of the theory belong, then state and prove the existence and uniqueness theorems of solutions of the Bending-Gradient problems for clamped and free plates, as well as for simply supported plates. The obtained results are afterward extended to the general case, i.e., when the compliance tensor related to generalized shear forces is not definite. 相似文献
1000.
Jony Javorski Eckert Fabio Mazzariol Santiciolli Elvis Bertoti Eduardo dos Santos Costa Fernanda Cristina Corrêa Ludmila Corrêa de Alkmin e Silva 《基于设计的结构力学与机械力学》2018,46(2):238-253
In the present work, the Adaptive-Weight Genetic Algorithm was employed in order to determine the gear shifting strategies that allow an automobile to work in the best compromise among fuel consumption, engine emissions, and vehicle performance. For the assessment of each of the three objective functions, a simulation model based on engine data and on the well-established equations of the longitudinal dynamics was developed. The driving cycle chosen for the calculations was the FTP-75, which takes into account both cold and hot starts, meaning that the transient operation during the warm-up of the catalyst is also considered. 相似文献