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This contribution discusses the phenomena of retrograde condensation of one or two liquids. It w1 be shown that both phenomena can be well understood. Also the relation of retrograde condensation of one liquid phase with the condensation behavior of natural gas will be discussed. Similarly that of two liquid phases with multiple phase behavior occurring in low temperature reservoir fluids will be pointed out. 相似文献
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P Nürnberg I Barth E Fuhrmann C Lenzner T Losanova C Peters H P?che G Thiel 《Electrophoresis》1991,12(2-3):186-192
Germline and somatic instability of the human genome was studied, using synthetic oligonucleotides specific for simple repeat motifs. The following probes were used: (GTG)5, (GACA)4, (GATA)4, (CT)8, (TTAGGG)3, (GT)8, (GAA)6 and (GGAT)4. Each of them is unique with respect to the target regions recognized in the genome. Thus compilation of the various fingerprint data provides a complex map of the genome (and its deviations). While the fingerprints of differentiated somatic tissues never showed any alterations, in tumor tissues (namely gliomas) many changes could be detected. Most of the latter reflect secondary karyological aberrations. In nearly one third of the gliomas, drastically amplified and apparently monomorphic DNA fragments were identified. This marker should make it possible to deal with causal pathogenetic mechanisms as well as novel diagnostic strategies. 相似文献
4.
Kevin S. Peters 《Angewandte Chemie (International ed. in English)》1994,33(3):294-302
Why have molecules only been seen but not heard? For over a century chemists have probed reactions with various spectroscopic methods to learn about structures, dynamics, and reactivities of their molecules. What they have not done is to listen to their molecules react. Although the photoacoustic phenomenon has been known since 1880, it is only in the last twenty years that technology has developed to the point where sound waves produced by reacting molecules can be time resolved and the information contained within the waves deciphered. The information content within the photoacoustic wave is indeed rich, for one can learn about the dynamics and the magnitude of enthalpy changes associated with the reaction as well as the changes in molecular volume. This review article chronicles the development of time-resolved photoacoustic calorimetry and its application to a variety of reactions encountered in organic and organometallic chemistry and biochemistry. 相似文献
5.
A. Razavi V. Bellia D. Baekelmans M. Slawinsky S. Sirol L. Peters Ulf Thewalt 《Kinetics and Catalysis》2006,47(2):257-267
In this contribution, the stereochemistry of propylene insertion/propagation reactions with a variety of C
1 symmetric metallocene catalysts, containing bridged cyclopentadienyl-fluorenyl ligand for the preparation of highly stereoregular
polypropylene is presented. The impact of the distal substitutent’s size and composition and changes that the catalytic sites
undergo upon such substitution is elaborated. A comprehensive mechanism is proposed to explain the resulting catalytic changes
that bring about the irreversible C
s/C
1 site transformation and tactic behavior inversion. Furthermore the cyclopentadienyl’s combined distal/proximal and fluorenyl’s
frontal substituent effects on molecular weight, regio-, and stereoregularity of the final polymers are discussed. Finally,
stereoselectivities of C
2 and C
1 symmetric catalyst systems are compared. It is shown that current high performance C
1 symmetric catalyst systems with central site chirality can be isotactic selective as well or even better in certain aspects
than the C
2 symmetric bridged bisindenyl-based metallocene catalysts.
The text was submitted by the authors in English. 相似文献
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Hans Peters Hans van der Stel Ton Storcken 《Mathematical Methods of Operations Research》1993,38(2):213-229
A voting scheme assigns to each profile of alternatives reported byn individuals a compromise alternative. A voting scheme is strategy-proof if no individual is better off by lying, i.e., not reporting a best alternative. In this paper the main results concern the case where the set of alternatives is the Euclidean plane and the preferences are Euclidean. It is shown that for strategy-proof voting schemes continuity is equivalent to convexity of the range of the voting scheme. Using a result by Kim and Roush (1984), this leads to characterizations of surjective or unanimous, anonymous, strategy-proof voting schemes.Furthermore, the paper contains an extensive discussion of related results in the area. 相似文献
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