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排序方式: 共有152条查询结果,搜索用时 15 毫秒
91.
Oskar Nuyken Juan Rueda Sanchez Brigitte Voit 《Macromolecular rapid communications》1997,18(2):125-131
poly[isobutene-co-(p,m-chloromethylstyrene)]-graft-poly(2-methyl-2-oxazoline) graft copolymers ( GP ) were prepared by the “grafting from” method throught the cationic polymerization of 2-methyl-2-oxazoline (MeOXA) initiated by a statistical copolymer is isobutene and chloromethylstyrene. The unusual viscosity behavior in chloroform solution of these polymers, the dynamic laser light scattering analysis in aqueous solution, as well as the solubility in polar solvents like water and methanol demonstrate the amphiphilic character of the graft copolymers and indicate the formation of aggregates in solution. 相似文献
92.
M A García C Solans J J Aramayona S Rueda M A Bregante 《Journal of chromatographic science》1999,37(6):199-202
A simple and sensitive high-performance liquid chromatography method is developed for the determination of orbifloxacin (ORB) in rabbit plasma. Sample preparations are carried out by adding phosphate buffer (pH 7.4, 0.1 M) and extracting with trichloromethane. ORB and the internal standard, norfloxacin (NOR), are separated on a reversed-phase column using an aqueous phosphate buffer-acetonitrile (80:20, v/v) mobile phase. The concentrations of ORB and NOR eluting from the column with retention times of 2.16 and 3.09 min, respectively, are monitored by fluorescence detection at 338 (excitation) and 425 nm (emission). The method is shown to be linear from 4 to 1500 ng/mL (regression coefficient r2 = 0.999). The quantitation and detection limits are 4 and 9 ng/mL, respectively. Mean recovery is determined as 92% by the analysis of plasma standards containing 150, 750, and 1500 ng/mL. Inter- and intra-assay precisions were 4 and 3%, respectively. 相似文献
93.
Juan Luis Manríquez Zepeda Juvenal Rueda Paz Manuel Avila Aoki Shi-Hai Dong 《Entropy (Basel, Switzerland)》2022,24(6)
We study both pentapartite GHZ and W-class states in the noninertial frame and explore their entanglement properties by carrying out the negativities including 1-4, 2-3, and 1-1 tangles, the whole entanglement measures such as algebraic and geometric averages and , and von Neumann entropy. We illustrate graphically the difference between the pentapartite GHZ and W-class states. We find that all 1-4, 2-3 tangles and the whole entanglements, which are observer dependent, degrade more quickly as the number of accelerated qubits increases. The entanglements of these quantities still exist even at the infinite acceleration limit. We also notice that all 1-1 tangles of pentapartite GHZ state where , whereas all 1-1 tangles of the W-class state and are unequal to zero, e.g., but and disappear at and , respectively. We notice that the entanglement of the pentapartite GHZ and W-class quantum systems decays faster as the number of accelerated particles increases. Moreover, we also illustrate the difference of von Neumann entropy between them and find that the entropy in the pentapartite W-class state is greater than that of GHZ state. The von Neumann entropy in the pentapartite case is more unstable than those of tripartite and tetrapartite subsystems in the noninertial frame. 相似文献
94.
Abraham Rueda Zoca 《Journal of Mathematical Analysis and Applications》2022,505(1):125447
We study the presence of L-orthogonal elements in connection with Daugavet centers and narrow operators. We prove that if and is a Daugavet center with separable range then, for every non-empty -open subset W of , it follows that contains some L-orthogonal to Y. In the context of narrow operators, we show that if X is separable and is a narrow operator, then given and any non-empty -open subset W of then W contains some L-orthogonal u so that . In the particular case that is separable, we extend the previous result to . Finally, we prove that none of the previous results holds in larger density characters (in particular, a counterexample is shown for under the assumption ). 相似文献
95.
96.
We apply the optimality conditions of nondifferentiable minimax programming to formulate a general second-order Mond-Weir dual to the nondifferentiable minimax programming involving second-order pseudo-quasi Type I functions. We establish also weak, strong, and strict converse duality theorems.Research supported by the Council of Scientific and Industrial Research, New Delhi, India, Research Scheme-25 (0132)/04/EMR-II. 相似文献
97.
Li Hong Jovana V. Mili Paramvir Ahlawat Marko Mladenovi Dominik J. Kubicki Farzaneh Jahanabkhshi Dan Ren María C. Glvez‐Rueda Marco A. Ruiz‐Preciado Amita Ummadisingu Yuhang Liu Chengbo Tian Linfeng Pan Shaik M. Zakeeruddin Anders Hagfeldt Ferdinand C. Grozema Ursula Rothlisberger Lyndon Emsley Hongwei Han Michael Graetzel 《Angewandte Chemie (International ed. in English)》2020,59(12):4691-4697
Formamidinium (FA) lead iodide perovskite materials feature promising photovoltaic performances and superior thermal stabilities. However, conversion of the perovskite α‐FAPbI3 phase to the thermodynamically stable yet photovoltaically inactive δ‐FAPbI3 phase compromises the photovoltaic performance. A strategy is presented to address this challenge by using low‐dimensional hybrid perovskite materials comprising guaninium (G) organic spacer layers that act as stabilizers of the three‐dimensional α‐FAPbI3 phase. The underlying mode of interaction at the atomic level is unraveled by means of solid‐state nuclear magnetic resonance spectroscopy, X‐ray crystallography, transmission electron microscopy, molecular dynamics simulations, and DFT calculations. Low‐dimensional‐phase‐containing hybrid FAPbI3 perovskite solar cells are obtained with improved performance and enhanced long‐term stability. 相似文献
98.
The paper considers the problem of estimating the population mean using auxiliary information. We propose a new model-based
estimator of the population mean, based on local polynomial regression. This estimator exhibits several attractive properties
under the model-based approach. The estimator is compared to a number of methods which have been proposed in the literature
via a simulation study based on several populations. 相似文献
99.
Pietsch’s domination theorem, which is known for linear, multilinear and polynomial mappings, is extended to a larger class
of nonlinear mappings. 相似文献
100.
We investigate the nature of some critical decay processes in a bounded bistable reaction-diffusion system, through a perturbative expansion of its nonequilibrium potential. We elucidate the scaling behavior of the damped relaxation time. 相似文献