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11.
Ohne Zusammenfassung
On the local zeta function of Shimura varieties. Monodromy filtration and vanishing cycles in unequal characteristic相似文献
12.
Emission and UV-vis absorption spectra of (hydrotris(pyrazolyl)borato)(triphenylarsine)copper(I), (CuTpAsPh3), (hydrotris(pyrazolyl)borato)(triethylamine)copper(I), (CuTpNEt3), and (hydrotris(pyrazolyl)borato)(triphenylphosphine)copper(I), (CuTpPPh3), are reported. The spectra of the arsine complex contain low-energy bands (with a band maximum at 16,500 cm(-1) in emission and a weak shoulder centered at about 25,000 cm(-1) in absorption) that are not present in the corresponding spectra of the amine or phosphine complexes. The lowest energy electronic transition is assigned to ligand to ligand charge transfer (LLCT) with some contribution from the metal. This assignment is consistent with PM3(tm) molecular orbital calculations that show the HOMO to consist primarily of pi orbitals on the Tp ligand (with some metal orbital character) and the LUMO to be primarily antibonding orbitals on the AsPh3 ligand (also with some metal orbital character). The absorption shoulder shows a strong negative solvatochromism, indicative of a reversal or rotation of electric dipole upon excitation, and consistent with a LLCT. The trends in the energies of the electronic transitions and the role of the metal on the LLCT are discussed. 相似文献
13.
Singh SB Zink DL Heimbach B Genilloud O Teran A Silverman KC Lingham RB Felock P Hazuda DJ 《Organic letters》2002,4(7):1123-1126
[structure: see text] HIV-1 integrase is a critical enzyme for viral replication, and its inhibition is an emerging target for potential antiviral chemotherapy. We have discovered a novel inhibitor, integramycin, from screening of fermentation extracts using an in vitro assay. Integramycin possesses a hexacyclic ring system and exhibited an IC50 value of 4 microM against HIV-1 integrase (strand transfer). The isolation, structure elucidation, stereochemistry, conformation, and biological activity has been described. 相似文献
14.
Abstract The reflection spectrum for visible light is examined for the cholesteric and blue phases of chiral CE6. Pronounced side band oscillations are observed. The Bragg wavelength for total reflection diverges towards the smectic phase with an exponent v = 0·71±0·05. Going from the cholesteric phase to BPI, the lattice parameter increases by (2)1/2. Evidence is given for the existence of a long-lived supercooled blue phase (BPS). 相似文献
15.
Bis‐clickable Mesoporous Silica Nanoparticles: Straightforward Preparation of Light‐Actuated Nanomachines for Controlled Drug Delivery with Active Targeting 下载免费PDF全文
Dr. Achraf Noureddine Dr. Magali Gary‐Bobo Dr. Laure Lichon Dr. Marcel Garcia Prof. Jeffrey I. Zink Dr. Michel Wong Chi Man Dr. Xavier Cattoën 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(28):9624-9630
Bis(clickable) mesoporous silica nanospheres (ca. 100 nm) were obtained by the co‐condensation of TEOS with variable amounts (2–5 % each) of two clickable organosilanes in the presence of CTAB. Such nanoparticles could be easily functionalized with two independent functions using the copper‐catalyzed alkyne‐azide cycloaddition (CuAAC) reaction to transform them into nanomachines bearing cancer cell targeting ligands with the ability to deliver drugs on‐demand. The active targeting was made possible after anchoring folic acid by CuAAC click reaction, whereas the controlled delivery was performed by clicked azobenzene fragments. Indeed, the azobenzene groups are able to obstruct the pores of the nanoparticles in the dark whereas upon irradiation in the UV or in the blue range, their trans‐to‐cis photoisomerization provokes disorder in the pores, enabling the delivery of the cargo molecules. The on‐command delivery was proven in solution by dye release experiments, and in vitro by doxorubicin delivery. The added value of the folic acid ligand was clearly evidenced by the difference of cell killing induced by doxorubicin‐loaded nanoparticles under blue irradiation, depending on whether the particles featured the clicked folic acid ligand or not. 相似文献
16.
Placement and characterization of pairs of luminescent molecules in spatially separated regions of nanostructured thin films 总被引:1,自引:0,他引:1
Minoofar PN Hernandez R Chia S Dunn B Zink JI Franville AC 《Journal of the American Chemical Society》2002,124(48):14388-14396
Methods of making mesostructured sol-gel silicate thin films containing two different molecules deliberately placed in two different spatially separated regions in a one-step, one-pot preparation are developed and demonstrated. When the structure-directing agent is the surfactant cetyltrimethylammonium bromide, the structure is 2-D hexagonal with lattice spacings between 31.6 and 42.1 angstroms depending on the dopant molecules and their concentrations. The three general strategies that are used to place the molecules are philicity (like dissolves like), bonding, and bifunctionality. These strategies take advantage of the different chemical and physical properties of the regions of the films. These regions are the inorganic silicate framework, the hydrophobic organic interior of the micelles, and the ionic interface between them. Luminescent molecules that possess the physical and chemical properties appropriate for the desired strategies are chosen. Lanthanide and ruthenium complexes with condensable trialkoxysilane groups are incorporated into the silicate framework. 1,4-Naphthoquinone, pyrene, rhodamine 6G and coumarin 540A, and lanthanides with no condensable trialkoxysilanes occupy the hydrophobic core of micelles by virtue of their hydrophobicity. The locations of the molecules are determined by luminescence spectroscopy and by luminescence lifetime measurements. In all cases, the long-range order templated into the thin film is verified by X-ray diffraction. The simultaneous placement of two molecules in the structured film and the maintenance of long-range order require a delicate balance among film preparation methodology, design of the molecules to be incorporated in specific regions, and concentrations of all of the species. 相似文献
17.
We synthesized tunable far-infrared radiation at frequencies higher than 9 THz (300 cm (-1)) by mixing CO(2) laser, (15)NH(3) laser, and microwave radiation in a W-Co metal-insulator-metal diode. We used this farinfrared radiation to accurately measure torsion-rotation transitions of CH(3)OH in the 8-9-THz region. We also measured the frequency of the aP(7, 3) (15)NH(3) laser transition. 相似文献
18.
19.
M. G. Grigorian Robert E. Zink 《Proceedings of the American Mathematical Society》2003,131(4):1137-1149
If one discards some of the elements from the Walsh family, an ancient example of a system that serves as a Schauder basis for each of the -spaces, with , the residual system will not be a Schauder basis for any of those spaces. Nevertheless, Price has shown that each member of a large class of such subsystems is complete on subsets of that have measure arbitrarily close to . In the present work, it is shown that subsystems of this kind can be multiplicatively completed in such a way that the resulting systems are quasibases for each space , , from which the earlier completeness result follows as a corollary.
20.
Julius Zink 《Fresenius' Journal of Analytical Chemistry》1933,91(7-8):246-258
Zusammenfassung Für die Beurteilung des Wassers auf seine Fähigkeit, Blei zu lösen, ergeben sich nach den vorstehenden Ausführungen folgende Gesichtspunkte.Die Hydrocarbonate vermindern das Bleilösungsvermögen des Wassers von allen Anionen am stärksten, da die entstehenden Bleiearbonate die geringste Löslichkeit besitzen. Demgegenüber begünstigt die freie Kohlensäure wiederum die Bleiaufnahme, indem sie lösend auf die Bleicarbonate wirkt und Bleihydrocarbonat bildet. Sofern sie allein auf Blei einwirkt, vermindert sie zunächst die Bleiaufnahme, da Bleicarbonat entsteht. Erst die darüber hinaus vorhandene Kohlensäure wirkt lösend, wie es die theoretische Betrachtung von Paul, Ohlmüller, Heise und Auerbach erfordert. 相似文献