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1.
Michael Binnewies Marion Jerzembeck Andreas Kornick 《Angewandte Chemie (International ed. in English)》1991,30(7):745-753
One of the modern high technologies which has advanced enormously in the last few years is glass fiber technology. This is used in the manufacture of glass fibers for lighting purposes and for the optical transfer of analog and digital data with a high transfer density. The technical demands made on the glass fibers required for data transfer, the optical waveguides, are extremely high and are already fulfilled to a large extent by industry. At present about four million kilometers of fiber, worth ca. 800 million DM are produced worldwide (10% in the Federal Republic of Germany). Numerous chemical processes take place during the manufacture of optical waveguides. However, in contrast both to the high and constantly growing demands on the quality and to the increasing production volume of such fibers, little is in fact known about the reactions involved. The present article will attempt to develop a picture of the multifarious reactions occurring in the course of this technical process on the basis of literature data and our own studies. 相似文献
2.
3.
CuAl2Cl8. Preparation and Crystal Structure. Crystals of CuAl2Cl8 have been prepared. Their remission spectrum agrees with that of gaseous CuAl2Cl8. The crystal structure (P21/c;a = 6.614, b = 7.376, c = 12.319 Å; β = 94.11°) shows a molecular lattice with Cu in square planar coordination, which is completed to a stretched octahedron (as in solid CuCl2) by two Cl atoms from neighbour molecules. Al has tetrahedral coordination. 相似文献
4.
The Catalysed Volatilization of Red Phosphorus and of Claudetite The catalysis of the volatilization of Pred (as P4) by AlCl3,g, and of the volatilization of claudetite (as As4O6) by I2,g is observed by mass spectrometry. 相似文献
5.
Phosphorus(III) Thiohalides: Sd?P? F and S?P? Br. Mass Spectrometric Investigations The compounds S?P? F and S?P? Br are formed by reaction of P(S)FBr2 and P(S)Br3, respectively, with silver at temperatures of about 800 K. S?P? Br is also formed by pyrolysis of P(S)Br3 at temperatures above 298 K. Mass spectrometric equilibrium measurements lead to the heat of formation of S?P? F: ΔH°298(SPFg) = ?260.8 kJ/mol. 相似文献
6.
Binnewies J. Knieh B. A. Kramer G. 《Zeitschrift fur Physik C Particles and Fields》1995,65(3):471-480
We present new sets of fragmentation functions for charged pions and kaons, both at leading and next-to-leading order. They are fitted to TPC data taken at energy
=29 GeV and describe excellently a wealth of othere
+
e
– data on charged-hadron production, ranging from
=5.2 GeV way up to LEP 1 energy. They also agree with data on the production of neutral pions and kaons, if one makes the natural assumption that the respective fragmentation functions are related to the charged counterparts bySU(2) symmetry. We also list simple parameterizations of thex andQ
2 dependence of our results, which may be implemented conveniently in applications.Supported by Bundesministerium für Forschung und Technologie, Bonn, Germany, under Contract 05 6 HH 93P (5), and by EEC ProgramHuman Capital and Mobility through NetworkPhysics at High Energy Colliders under Contract CHRX-CT93-0357 (DG12 COMA) 相似文献
7.
Wilpers G Binnewies T Degenhardt C Sterr U Helmcke J Riehle F 《Physical review letters》2002,89(23):230801
We demonstrate how to realize an optical clock with neutral atoms that is competitive to the currently best single ion optical clocks in accuracy and superior in stability. Using ultracold atoms in a Ca optical frequency standard, we show how to reduce the relative uncertainty to below 10(-15). We observed atom interferences for stabilization of the laser to the clock transition with a visibility of 0.36, which is 70% of the ultimate limit achievable with atoms at rest. A novel scheme was applied to detect these atom interferences with the prospect to reach the quantum projection noise limit at an exceptional low instability of 4 x 10(-17) in 1 s. 相似文献
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As described in the preceding article, all elements with atomic masses above that of iron and also the radioactive elements thorium and uranium have been formed by a supernova star explosion. Their long‐lived isotopes of thorium and uranium are now distributed in the earth crust. The chemistry of uranium and thorium is of less importance, but these elements can be used to produce enormous amounts of energy in nuclear power stations. It will be described how it works. Surprisingly, small natural nuclear reactors were producing heat during hundreds of thousand years. Subsequently, we are dealing with this phenomenon, the principle of nuclear fission, the different types of nuclear reactors, security aspects and new developments. 相似文献
10.