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排序方式: 共有158条查询结果,搜索用时 171 毫秒
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Coll R. Saurina J. Escoda L. Suñol J. J. 《Journal of Thermal Analysis and Calorimetry》2018,131(2):1277-1286
Journal of Thermal Analysis and Calorimetry - This paper reports the effects of welan gum on the hydration and hardening behaviors of Portland cement (PC) by using X-ray diffractometry, mercury... 相似文献
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Martín A. Iglesias Arteaga Roxana Pérez Gil Vivian Leliebre Lara Carlos S. Pérez Martinez Francisco Coll Manchado Arístides Rosado Pérez 《合成通讯》2013,43(8):1381-1386
The synthesis of a plant growth promoter furostanol which bears the characteristic functionality of teasterone on rings A and B is described. 相似文献
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B. Cantó C. Coll E. Sánchez S. C. Cardona J. Navarro-Laboulais 《Journal of mathematical chemistry》2014,52(4):1023-1035
The dynamics of the composition of chemical species in reacting systems can be characterized by a set of autonomous differential equations derived from mass conservation principles and some elementary hypothesis related to chemical reactivity. These sets of ordinary differential equations (ODEs) are basically non-linear, their complexity grows as much increases the number of substances present in the reacting media and can be characterized by a set of phenomenological constants (kinetic rate constants) which contains all the relevant information about the physical system. The determination of these kinetic constants is critical for the design or control of chemical systems from a technological point of view but the non-linear nature of the ODEs implies that there are hidden correlations between the parameters which maybe can be revealed with a identifiability analysis. 相似文献
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Carmen Coll Elena Aznar Ramón Martínez‐Máñez Prof. M. Dolores Marcos Dr. Félix Sancenón Dr. Juan Soto Dr. Pedro Amorós Joan Cano Dr. Eliseo Ruiz Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(33):10048-10061
We report the preparation of a MCM‐41 mesoporous material that contains the dye [Ru(bipy)3]Cl2 (bipy=bipyridine) inside the mesopores and functionalised with suitable binding groups at the entrance of the pores. Solids S1 – S3 were obtained by the reaction of the mesoporous material with N‐methyl‐N′‐propyltrimethoxysilylimidazolium chloride, N‐phenyl‐N′‐[3‐(trimethoxysilyl)propyl]thiourea, or N‐phenyl‐N′‐[3‐(trimethoxysilyl)propyl]urea, respectively. A study of the dye delivery of these systems in buffered water (pH 7.0, 2‐[4‐(2‐hydroxyethyl)piperazin‐1‐yl]ethanesulfonic acid (HEPES), 10?3 mol dm?3) in the presence of a family of carboxylate ions was carried out. In the interaction of the anions with the surface of the solids, the response depends on the characteristics of the binding groups (i.e., imidazolium, urea and thiourea) at the pore outlets and their specific interaction with the corresponding anion. The interaction of long‐chain carboxylate ions with the binding sites at the surface of the solids resulted in a remarkable inhibition of the delivery of the dye. This inhibition was observed clearly for the dodecanoate anion, whereas the octanoate, decanoate, cholate, deoxycholate, glycodeoxycholate and taurocholate anions induced a certain pore blockage that varied according to the solid studied. The interaction of smaller anions, such as acetate, butanoate, hexanoate and octanoate, with the solids had no effect on the dye release process. The possible use of the gating system for the chromo‐fluorogenic detection of anionic surfactants through selective dye delivery inhibition was also explored. Molecular dynamic simulations that use force‐field methods have been made to theoretically study the capping carboxylate mechanism. The calculations are in agreement with the experimental results, thus allowing a representation of the dye delivery inhibition in the presence of long‐chain carboxylate ions. 相似文献
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We characterize all the quadratic polynomial differential systems having a polynomial inverse integrating factor and provide explicit normal forms for such systems and for their associated first integrals. We also prove that these families of quadratic systems have no limit cycles. 相似文献
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R. Coll L. Escoda J. Saurina J. L. Sánchez-Llamazares B. Hernando J. J. Suñol 《Journal of Thermal Analysis and Calorimetry》2010,99(3):905-909
Three magnetic shape memory alloys: Mn50Ni50−x
Sn
x
(x = 5, 7.5, and 10) were produced as bulk polycrystalline ingots by arc melting. The structural austenite–martensite transformation
was checked by calorimetry. The transformation temperatures decrease as increasing the Sn content. The same trend is found
in the entropy and enthalpy changes related to the transformation. The control of the valence electron by atom e/a determines the transformation temperatures range in this kind of alloys and it is possible to develop alloys that can be
candidates in applications as sensors and actuators. Furthermore, X-ray diffraction was performed to check the crystalline
structure at room temperature. 相似文献