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991.
An experimental and theoretical study of the self-assembly of gold nanoparticles at the surface of functionalized multiwalled carbon nanotubes 总被引:3,自引:0,他引:3
Sainsbury T Stolarczyk J Fitzmaurice D 《The journal of physical chemistry. B》2005,109(34):16310-16325
This paper reports the findings of a detailed study of the self-assembly of gold nanoparticles at the surface of carbon nanotubes (CNTs). The study included the development of a predictive model for the interactions (charge transfer, van der Waals, osmotic, elastic, nonelastic, and covalent) between tetraoctylammonium bromide-stabilized (TOAB) gold nanoparticles and alkyl- and alkylthiol-modified multiwalled carbon nanotubes (MWCNTs). It also included the measurement of the coverage of gold nanoparticles at the surface of the above MWCNTs as a function of increasing alkyl chain length. One key finding is that it is possible to predict with a high degree of accuracy using the above model the measured coverage of gold nanoparticles adsorbed, either noncovalently or covalently, at the surface of a MWCNT. Another key finding is that, as predicted, under well-defined conditions the measured coverage of nanoparticles is very sensitive to the nature of the modified CNT surface and the contiguous environment, providing valuable insights that will underpin the rational design of functional nanoscale devices assembled from nanoparticle and CNT building blocks. 相似文献
992.
Jacek Jachymski 《Journal of Fixed Point Theory and Applications》2009,5(1):47-61
We revisit a fixed point theorem for contractions established by Felix Browder in 1968. We show that many definitions of contractive
mappings which appeared in the literature after 1968 turn out to be equivalent formulations or even particular cases of Browder’s
definition. We also discuss the problem of the existence of approximate fixed points of continuous mappings; in particular,
we settle it in the affirmative for Browder contractions. Finally, we recall three problems concerning Browder contractions
which remain unsolved.
With great respect for Professor Felix E. Browder 相似文献
993.
Jacek Tabor 《Journal of Mathematical Analysis and Applications》2004,299(2):651-662
Let X be a Banach space, let
994.
Gawroński J Grajewski J Drabowicz J Mikołajczyk M 《The Journal of organic chemistry》2003,68(25):9821-9822
A simple nonempirical method for the assignment of absolute configuration of N-phthalimidosulfoximines and related S-chiral sulfoxides, based on exciton-coupled circular dichroism, is presented. 相似文献
995.
Kazimierz Łątka Jacek Gurgul Andrzej W. Pacyna Yuriy Verbovytsky Birgit Heying C. Peter Sebastian Rainer Pöttgen 《Hyperfine Interactions》2008,184(1-3):39-43
The intermetallic compound TbRhSn was investigated in detail by X-ray, magnetic susceptibility measurements and 119Sn Mössbauer spectroscopy. This compound undergoes a transition from a paramagnetic to an antiferromagnetic state at T N = 20.8(2) K. The 119Sn Mössbauer spectrum recorded at 4.2 K can be well fitted as a composition of three subspectra with the same intensities, magnitudes of H hf, ΔE Q, and δ is, in agreement with the model of triangular-like antiferromagnetic arrangements of equal magnetic Tb moments lying in the basal ab-plane deduced from neutron diffraction studies (Szytu?a et al., J Alloys Compd 244:94–98, 1996). 相似文献
996.
Florence Draux Pierre Jeannesson Cyril Gobinet Josep Sule-Suso Jacek Pijanka Christophe Sandt Paul Dumas Michel Manfait Ganesh D. Sockalingum 《Analytical and bioanalytical chemistry》2009,395(7):2293-2301
Identifying early cellular events in response to a chemotherapy drug treatment, in particular at low doses that will destroy
the highest possible number of cancer cells, is an important issue in patient management. In this study, we employed Fourier
transform infrared spectroscopy as a potential tool to access such information. We used as model the non-small cell lung cancer
cell line, Calu-1. They were exposed to cytostatic doses (0.1 to 100 nM for 24, 48 and 72 h) of gemcitabine, an anti-tumour
drug, currently used in treatment of lung cancer patients. In these conditions, inhibition of cell proliferation ranges from
weak (≤5%), to moderate (∼23%), to high (82–95%) without affecting cell viability. Following drug treatment as a function
of doses and incubation times, the spectra of cell populations and of individual cells were acquired using a bench-top IR
source and a synchrotron infrared microscope. It is demonstrated that spectral cell response to gemcitabine is detectable
at sublethal doses and that effects observed on cell populations are similar to those from single cells. Using cluster analysis,
spectra could be classified in two main groups: a first group that contains spectra of cells exhibiting a weak or moderate
proliferation rate and a second group with spectra from cells presenting a high growth inhibition. These results are promising
since they show that effects of subtoxic doses can also be monitored at the single-cell level with the clinical implications
that this may have in terms of patient benefit and response to chemotherapy. 相似文献
997.
Reaction rates of interfacial polycondensation of bisphenol A and chlorobisphenol II with isophthaloyl chloride were investigated. Rate constants and activation energies were determined The reaction rate was found to depend on stirring speed, catalyst, type of bisphenol, and temperature. 相似文献
998.
999.
1000.
In the present study, pervaporation was applied to the determination of tetrachloroethene (PCE) and dichloromethane (DCM) in liquid samples. PCE is the most commonly used solvent in drycleaning processes. PCE belongs to group 2A of carcinogens (probably carcinogenic to humans) according to the classification of the International Agency for Research on Cancer (IARC). DCM is also widely used as an industrial solvent for the purification and isolation of intermediates or products. DCM is classified as a “possible” human carcinogen by the IARC. The aim of this study was to evaluate a new procedure for the determination of DCM and PCE in liquid samples based on the pervaporative removal of DCM and PCE from liquid samples as an analyte isolation/enrichment technique, followed by a direct aqueous injection of the extracts onto the column of a gas chromatograph equipped with an electron capture detector (DAI-GC-ECD). The basic parameters of the new PV-DAI-GC-ECD procedure were evaluated. 相似文献