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排序方式: 共有130条查询结果,搜索用时 15 毫秒
41.
42.
Chen R Pearce DJ Fortuna S Cheung DL Bon SA 《Journal of the American Chemical Society》2011,133(7):2151-2153
The fabrication of polymer vesicles with a colloidal armor made from a variety of nanoparticles is demonstrated. In addition, it is shown that the armored supracolloidal structure can be postmodified through film-formation of soft polymer latex particles on the surface of the polymersome, hereby effectively wrapping the polymersome in a plastic bag, as well as through formation of a hydrogel by disintegrating an assembled polymer latex made from poly(ethyl acrylate-co-methacrylic acid) upon increasing the pH. Furthermore, ordering and packing patterns are briefly addressed with the aid of Monte Carlo simulations, including patterns observed when polymersomes are exposed to a binary mixture of colloids of different size. 相似文献
43.
Carmelo Sgarlata Giuseppe Arena Cosimo G. Fortuna Domenico Sciotto 《Supramolecular chemistry》2016,28(5-6):544-550
AbstractThe binding features of a sulfonato-calix[4]arene with pyridinium-based gemini guests have been investigated in water at physiological condition by NMR spectroscopy. Results provided converging evidence showing that guests having different size, shape and flexibility formed water-soluble homodimeric supramolecular capsules. The remarkably large encapsulation efficiency of the anionic calixarene host towards these bis(pyridinium) gemini guests results from the favourable combination of electrostatic and hydrophobic interactions. The introduction of short and rigid spacers between the two positively charged heads of the guest improves the efficiency of the capsule formation. The insertion of a substituent into the pyridinium ring of the guest dramatically affects both the association constants and the binding modes. 相似文献
44.
Chernyshev A Fleischmann T Koehn EM Lesley SA Kohen A 《Chemical communications (Cambridge, England)》2007,(27):2861-2863
New findings lead to a revised understanding of the substrates' binding order, the role of the substrate as an activator, and the observed lag phase in the FDTS catalyzed reaction. 相似文献
45.
Jeff Fortuna Alyaa H. Elzibak Zhaoyang Fan John F. MacGregor Michael D. Noseworthy 《Journal of Chemometrics》2012,26(5):170-179
The liver is a highly vascular organ with a dual blood supply, and it performs a remarkable number of vital functions. Here, we show, through measurement of blood oxygen level‐dependent (BOLD) signal, that liver arterial and hepatic portal blood supplies can be modulated through hyperoxia exposure and by consumption of a standardized meal, respectively. As such, we suggest that hyperoxia modulates the hepatic arterial BOLD signal, whereas a controlled meal changes predominantly the hepatic portal BOLD signal. The hemodynamics of the dual liver blood supplies in response to the aforementioned challenges are complex and variable across subjects, making a general linear model‐based analysis difficult. Therefore, we present the application of two local (at each voxel) hemodynamic response‐independent techniques—principal component analysis and partial least squares—to observe the hypothesized reduction in BOLD contrast during cycles of hyperoxic breathing, when comparing preprandial versus postprandial states in a normally functioning liver. We illustrate the ability of our techniques to differentiate between healthy and diseased livers with an analysis of 17 subjects—11 with normal livers and 6 with liver disease (hepatitis or cirrhosis). Our local analysis can correctly classify all of the subjects. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
46.
47.
Zehavit Kohen 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1128-1151
Technology has an inseparable role in contemporary educational systems. Recent demands consider its informed integration in classrooms. The current study aims to investigate whether informed use of Interactive Whiteboard (IWB) technologies affects students’ real-time emotions in mathematics classes, through an integrative research model that combines two components: varying levels of technology integration and varied levels of problem-solving skills. Participants included 64 sixth-grade students who were assigned to one of two comparison groups who have been progressively exposed to different implementations of the research model. The study used a real-time judgment of emotions scale, and a reflective questionnaire. Findings indicate that when being exposed to informed IWB integration, more positive emotions arose in real-time during learning; specifically, toward understanding-performance, and when being required to demonstrate applying problem-solving skills. The study provides a holistic view that reinforces the interplay between the two components of the integrative research model, particularly as it supports the advantage of an informed IWB technology integration in a way that most successfully incorporated with the cognitive demand required from students. 相似文献
48.
Synchronization of moving chaotic agents 总被引:1,自引:0,他引:1
We consider a set of mobile agents in a two dimensional space, each one of them carrying a chaotic oscillator, and discuss the related synchronization issues under the framework of time-variant networks. In particular, we show that, as far as the time scale for the motion of the agents is much shorter than that of the associated dynamical systems, the global behavior can be characterized by a scaled all-to-all Laplacian matrix, and the synchronization conditions depend on the agent density on the plane. 相似文献
49.
Y. Dagan A. Kohen G. Deutscher 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,19(3):353-356
We have measured I(V) characteristics of c-axis planar tunnel junctions on Y1Ba2Cu3O 7 - δ films. Our results and their analysis provide experimental support for the importance of the two-dimensional character of
the YBCO band structure, and a method to measure the ratio between the Fermi energy of YBCO and the barrier height. The analysis
is based on the relation between the linear conductance background, related to the inelastic tunneling component, and the
zero bias conductance, related to the elastic one.
Received 24 September 2000 and Received in final form 15 November 2000 相似文献
50.
Yakov I. Tur’yan Fernando Mata Jorge Moyano Pavel Gorenbein Ron Kohen 《Journal of Solid State Electrochemistry》2007,11(1):10-20
The theory of the polarographic catalytic currents (mechanism CE) has been developed for the system: Ni2+-L-Xp− where L: pyridine (Py), nicotinamide (NA), N,N-diethylnicotinamide (DEN), nicotine (NC) and Xp−: NO−
3, AcO−, HPO2−
4 . The theory is based on the kinetic parallel heterogeneous catalytic reactions:
with the use of Langmuir’s adsorbed isotherm. The kinetic equations obtained for average and instantaneous currents allowed
to determine the Langmuir’s parameters (NA<DEN<NC), kinetic parameters and the contribution of reactions 1a and b to the summary catalytic currents. The k
h″ value rises with the increase of the NiX2−p stability constant. The correlation k
h″≫k
h′ was explained by the additional effect of the field electrode through Xp−. These effects base the reaction 1b instead of accepted early alternative reaction of the ligand exchange. In spite of the fact that k
h″≫k
h′, the contribution of the reaction 1a in the summary catalytic current attained more than 60% (Py, DEN) due to the influence of the ψ0 potential.
Dedicated to Professor Zbigniew Galus on the occasion of his 70th birthday and in recognition of his many contributions to
electrochemistry 相似文献
(1a) |
(1b) |