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61.
Two three-dimensional open-framework zinc phosphites, H2aem·Zn3(HPO3)4·0.5H2O (1) and H2apm·Zn3(HPO3)4 (2), have been synthesized by a phosphorous acid flux method, where aem=4-(2-aminoethyl)morpholine and apm=4-(3-aminopropyl)morpholine. Compound 1 crystallizes in the monoclinic system, P21/c, a=9.5852(7) Å, b=20.3941(8) Å, c=10.5339(8) Å, β=94.125(9)°, V=2053.8(2) Å3, Z=4, R1=0.0319, wR2=0.0628. Compound 2 crystallizes in the monoclinic system, P21/n, a=8.589(2) Å, b=14.020(3) Å, c=16.606(3) Å, β=97.190(8)°, V=1983.9(7) Å3, Z=4, R1=0.0692, wR2=0.1479. Both compounds are based on (3,4)-connected networks with 8- and 12-ring channels, which are constructed from Zn3(HPO3)4 clusters as the same secondary building units. These inorganic clusters are spatially organized by different structure-directing agents into different three-dimensional frameworks. 相似文献
62.
I. Delgadillo-Holtfort E. Neubauer J. S. Antoniow J. Gibkes M. Chirtoc B. K. Bein J. Pelzl 《The European physical journal. Special topics》2008,153(1):147-150
Photoacoustic effect and scanning near field microscopy
have been applied to characterise the thermal properties of diamond
crystallites which were coated by a Cu film, a Cr-film and a Cr-Cu film. The
Cu-coated diamond exhibits a considerable thermal barrier at the Cu-diamond
interface which had disappeared for the crystallites with a thin bond
Cr-layer between diamond and Cu. The local inspection of the thermal
conductivity with a thermal nano-probe operated in the 3ω-mode
reveals slight local variations of the thermal conductivity of the Cr-coated
crystallite. 相似文献
63.
64.
Dirk Steinhilber Torsten Rossow Dr. Stefanie Wedepohl Florian Paulus Dr. Sebastian Seiffert Prof. Dr. Rainer Haag 《Angewandte Chemie (International ed. in English)》2013,52(51):13538-13543
pH‐Cleavable cell‐laden microgels with excellent long‐term viabilities were fabricated by combining bioorthogonal strain‐promoted azide–alkyne cycloaddition (SPAAC) and droplet‐based microfluidics. Poly(ethylene glycol)dicyclooctyne and dendritic poly(glycerol azide) served as bioinert hydrogel precursors. Azide conjugation was performed using different substituted acid‐labile benzacetal linkers that allowed precise control of the microgel degradation kinetics in the interesting pH range between 4.5 and 7.4. By this means, a pH‐controlled release of the encapsulated cells was achieved upon demand with no effect on cell viability and spreading. As a result, the microgel particles can be used for temporary cell encapsulation, allowing the cells to be studied and manipulated during the encapsulation and then be isolated and harvested by decomposition of the microgel scaffolds. 相似文献
65.
Stefanie Pötz Heinz Wilkes Matthias Witt Brian Horsfield 《Rapid communications in mass spectrometry : RCM》2010,24(8):1185-1197
Four different geological sample types (a crude oil, a crude oil asphaltene, a reservoir core extract and a reservoir core asphaltene) have been characterized by negative ionization electrospray mass spectrometry at low and high mass resolution using a double‐focusing magnetic sector field mass spectrometer. The mass range, shape of the spectra and the signal distribution of the acidic constituents as well as the average molecular weights, the total ion abundance and signal intensity in the spectra were compared for the different sample types. Nominal mass classes have been evaluated and Kendrick mass plots were generated in order to identify homologous series. For the crude oil sample, accurate mass assignments were made by high‐resolution double‐focusing magnetic sector field mass spectrometry (DFMSFMS) and were compared with those obtained by negative ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). With both instrument types, compounds with the molecular composition CnH2n+zO2, among which carboxylic acids predominated, were the main acidic compound class detectable in negative ESI mass spectra. Good agreement was achieved for the double bond class distribution and the carbon number distribution of the O2 class. In addition, minor compound classes could be identified using FTICRMS. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
66.
S. Chotikaprakhan A. Haj-Daoud D. Dietzel R. Meckenstock E. Neubauer J. Pelzl B. K. Bein 《The European physical journal. Special topics》2008,153(1):175-178
The effective thermal depth profiles of copper-carbon
interface systems with and without additional metallic submicron bond layers
have been measured by means of modulated IR radiometry and have been
evaluated using a new quantity, the thermal (wave) contrast, defined with the help of the
calibrated thermal wave amplitudes. Useful correlations between the thermal wave contrast and the
mechanical adhesion strength between copper film and carbon substrate have
been found. By comparing the measurements based on thermal wave excitation and
contact-less IR detection with microscopic contact temperature measurements
close to the copper-carbon interface, the similarities between the two
experiments are discussed, and the advantages and problems related to the thermal wave contrast
are analyzed. 相似文献
67.
Stefanie Breukers Christer L. Øpstad Hans‐Richard Sliwka Vassilia Partali 《Helvetica chimica acta》2009,92(9):1741-1747
The oft‐claimed ‘good’ water solubility of the food color norbixin ( 3 ) could not be confirmed. In contrast, the potassium salt 5 of norbixin formed suitable dispersions. The surface and aggregation properties of salt 5 were investigated and compared with other naturally occurring and synthetic hydrophilic carotenoids (Table). 相似文献
68.
Seven organo‐bridged bis[tris(arylchalcogenolato)tin] compounds with the general formulae (R′E)3Sn–R–Sn(ER′)3 (R = –(CH2)4–, 1,4‐bis(methyl)benzene, 4,4′‐bis(methyl)biphenyl; R′ = Ph, 1‐Np, 2‐Np; E = S, Se) were synthesized and characterized by means of X‐ray diffractometry as well as NMR spectroscopy. Three different conformations of the arylchalcogenolato groups ER′ with respect to the bridging group R were rationalized and explained by means of quantum chemical investigations. 相似文献
69.
70.
Martin Hanke Nuutti Hyvönen Manfred Lehn Stefanie Reusswig 《BIT Numerical Mathematics》2008,48(2):245-264
We investigate the inverse source problem of electrostatics in a bounded and convex domain with compactly supported source.
We try to extract all information about the unknown source support from the given Cauchy data of the associated potential,
adopting by this previous work of Kusiak and Sylvester to the case of electrostatics. We introduce, and for the unit disk
we also compute numerically, what we call the discoidal source support, i.e., the smallest set made up by the intersection of disks within the domain, which carries a source compatible with the
given data.
AMS subject classification (2000) 35R30, 65N21 相似文献