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71.
Ohne Zusammenfassung 相似文献
72.
Goldenberg LM Kulikovska O Stumpe J 《Langmuir : the ACS journal of surfaces and colloids》2005,21(11):4794-4796
In a search for effective polymer film material for holographic surface patterning, commercially available azobenzene polyelectrolyte has been employed. Films of good optical quality in a wide range of thickness were produced. Optical dichroism up to 0.19 was induced upon irradiation with linearly polarized light. Surface relief gratings with amplitudes up to 630 nm and diffraction efficiency of 37% were inscribed by holographic exposure to the light of 488 nm. Due to the ionic nature of the material, the relief was stable at least up to the temperature of decomposition (ca. 200 degrees C) but could be erased and inscribed again by light. 相似文献
73.
Reich HJ Goldenberg WS Sanders AW Jantzi KL Tzschucke CC 《Journal of the American Chemical Society》2003,125(12):3509-3521
Chelation and aggregation in phenyllithium reagents with potential 6- and 7-ring chelating amine (2, 3) and 5-, 6-, and 7-ring chelating ether (4, 5, 6) ortho substituents have been examined utilizing variable temperature (6)Li and (13)C NMR spectroscopy, (6)Li and (15)N isotope labeling, and the effects of solvent additives. The 5- and 6-ring ether chelates (4, 5) compete well with THF, but the 6-ring amine chelate (2) barely does, and 7-ring amine chelate (3) does not. Compared to model compounds (e.g., 2-ethylphenyllithium 7), which are largely monomeric in THF, the chelated compounds all show enhanced dimerization (as measured by K = [D]/[M](2)) by factors ranging from 40 (for 6) to more than 200 000 (for 4 and 5). Chelation isomers are seen for the dimers of 5 and 6, but a chelate structure could be assigned only for 2-(2-dimethylaminoethyl)phenyllithium (2), which has an A-type structure (both amino groups chelated to the same lithium in the dimer) based on NMR coupling in the (15)N, (6)Li labeled compound. Unlike the dimer, the monomer of 2 is not detectably chelated. With the exception of 2-(methoxymethyl)phenyllithium (4), which forms an open dimer (12) and a pentacoordinate monomer (13), the lithium reagents all form monomeric nonchelated adducts with PMDTA. 相似文献
74.
Moore AJ Goldenberg LM Bryce MR Petty MC Moloney J Howard JA Joyce MJ Port SN 《The Journal of organic chemistry》2000,65(24):8269-8276
The synthesis of new S(2)O(4)-crown annelated tetrathiafulvalene (TTF) derivatives substituted with one terminal thiol group is described. Self-assembled monolayers (SAMs) of these compounds have been assembled on gold and platinum surfaces, the latter substrate giving improved quality films. SAMs of TTF derivative 16b are the most stable of those we have studied. Electrochemical data for SAMs of 5a, 5b, 8, 16a, and 16b in acetonitrile reveal two reversible one-electron waves, typical of the TTF system; the current increased linearly with scan rate, indicating a surface wave response. SAMs of 8, 16a, and 16b exhibited an electrochemical response in aqueous electrolytes, which was observed between 50 and 100 cycles. Moreover, if the potential scanned was limited to the first TTF oxidation, the cyclic voltammetry response was observed for at least 1000 cycles. Metal complexation by the crown ionophore of the SAMs in acetonitrile has been monitored by a positive shift in the first oxidation potential of the TTF unit (maximum DeltaE(1)(1/2) = 80 mV for Ag(+)). We also report the X-ray crystal structure of TTF-crown derivative 21 bearing two hydroxymethyl substituents, synthesized during the course of this work. The structure is characterized by infinite chains of molecules linked by strong intrachain hydrogen bonds between the terminal hydroxy groups. 相似文献
75.
76.
S Chanda Sarmishtha Bhattacharyya Tumpa Bhattacharjee SS Ghugre Swapan Kumar Basu S Muralithar RP Singh B Mukherjee RK Bhowmik SN Ray 《Pramana》2001,57(1):175-179
The high spin states in N=80 139Pr have been investigated by in-beam γ-spectroscopic techniques following the reaction 130Te (14N, 5n) reaction at E=75 MeV, using a gamma detector array, consisting of seven 23% compton-suppressed high purity germanium detectors and a multiplicity
ball of fourteen bismuth germanate elements. Based on γ-γ coincidence data, the level scheme of 139Pr has been considerably extended up to 7.2 MeV excitation. Tentative spin-parity assignments are done for the newly proposed
levels on the basis of the DCO ratios corresponding to strong gates and the available information from the earlier light ion
experiments. 相似文献
77.
78.
The propagation of stress waves through a chain of discs has been studied experimentally in Part I (Glam et al. [1]) and is
completed here with numerical investigation using the standard package ABAQUS. A fair agreement is found between experimental
findings and their simulations. Based on this agreement, parametric study of wave propagation through disc-chains was conducted.
Specifically, effects associated with changes in the disc diameter, material density, stiffness/rigidity and the number of
discs in the chain on the stressed chain have been studied. It was found that the propagation velocity of the evolved waves
increases with improving contacts between the chain’s discs by exposing the chain to a static load before its dynamic loading.
The wave- propagation velocity decreases with increase in the discs material density and it increases when its diameter increases.
In case of a chain composed of small diameter discs and/or small material density, the transmitted stress wave is first strengthened
and only at discs further down the chain it starts decaying. When checking the influence of the dynamic-loading duration it
was found that long dynamic-load duration dissolves quickly into short pulses. It was also found that there is a ‘characteristic’
wave for a given chain. This wave propagates with minimal dispersion. Dynamic loads having shorter time duration than the
‘characteristic’ one experiences significant attenuation. 相似文献
79.
S. E. Peltek T. N. Goryachkovskaya S. V. Bannikova S. V. Shekhovtsov B. G. Goldenberg A. K. Potashnikov V. M. Popik 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(9):1171-1174
The passive immunodiffusion reaction in a microfluidic system is investigated via the interaction between fluorescein human albumin conjugate and monoclonal antibodies. The topology of a microfluidic device suitable for this reaction was designed, and the device was fabricated using LIGA technology. A system for transitioning from the macro- to the microlevel is developed and produced. The dissociation constants and specificity of interaction in complexes formed as a result of the reaction between fluorescein human albumin conjugates and monoclonal antibodies are determined. The results from our study reveal that systems based on combinations of passive immunodiffusion reactions and microfluidic technologies are applicable for detecting antigens and antibodies in the analyzed fluids. 相似文献
80.
N. A. Timchenko R. M. Galimov A. M. Lider B. G. Goldenberg A. N. Shmakov 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(2):159-161
Data from measurements of the disintegration kinetics of hydrogen phases in palladium and titanium during annealing and irradiation with a synchrotron radiation bunch in the X-ray spectral region on the VEPP-3 LIGA Technology station are presented. The hydride phases in palladium and titanium remain stable at sample temperatures of 60°C and irradiation doses of up to 3000 J cm?3 during irradiation with a synchrotron radiation bunch and start to decompose during sample heating to a temperature of 90–100°C. 相似文献