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W. R. Schoeller A. R. Powell O. Hahn K. E. Pütter E. S. Simpson W. F. Hillebrand G. E. F. Lundell O. Ruff E. Schiller W. P. Headden H. Pied H. W. Webb R. J. Meyer O. Hauser W. B. Giles R. C. Wells E. F. Waterhouse G. T. Prior E. C. Deering L. Finckh J. H. Muller J. W. Mellor E. W. Todd V. Schwarz G. W. Sears und W. D. Treadwell 《Fresenius' Journal of Analytical Chemistry》1934,99(5-6):205-227
Ohne Zusammenfassung 相似文献
66.
Novak D. Smith G. H. Lowery A. J. Liu H. F. Waterhouse R. B. 《Optical and Quantum Electronics》1998,30(11-12):1021-1031
This paper describes two techniques for the implementation of millimetre-wave (mm-wave) wireless communication systems incorporating optical fibre distribution networks. Fibre chromatic dispersion can exhibit severe effects on the transportation of mm-wave frequencies over fibre, resulting in greatly reduced post-detection rf powers. Each mm-wave fibre–wireless system demonstrated here incorporates a method for the generation and modulation of an optical mm-wave carrier, which enables the effect of fibre dispersion to be significantly reduced. One set-up is a direct-detection scheme where optical single-sideband (SSB) with carrier modulation is used to overcome fibre dispersion effects. The other system employs a self-heterodyne arrangement in which a dual-frequency optical source generates a low phase-noise mm-wave beat signal. Data transmission is achieved by externally modulating the dual-mode signal and reduced effects of fibre dispersion are observed. 相似文献
67.
Jiahao Guo Yitao Cao Run Shi Geoffrey I. N. Waterhouse Li‐Zhu Wu Chen‐Ho Tung Tierui Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(25):8531-8535
Synthesizing nanomaterials with anisotropic architectures, especially two‐dimensional (2D) nanosheets (NSs), is a key focus of materials science research. Metal sulfide nanosheets (MSNSs) are typically obtained involving exfoliation of bulk metal sulfides with layered structures. The synthesis of NSs of intrinsically non‐layered metal sulfides has received relatively less attention. Metal alkanethiolates with lamellar structures are now shown to serve as effective scaffolds for constructing NSs. A novel photochemical step was employed to transform 2D metal thiolates into MSNSs. By this strategy the 2D nature of metal thiolate precursors was preserved in the final products, resulting in the successful synthesis of NSs of binary PbS, CdS, and Cu9S5, as well as ternary wurtzite CuInS2, Cu2SnS3. Results encourage the wider utilization of photochemical strategies in the synthesis of anisotropic MSNSs. 相似文献
68.
William C. Waterhouse 《Linear and Multilinear Algebra》1985,17(2):101-106
We show that over any cummutative ring R,the combinations, of 2 × 2 minors are the only quadratic forms vanishing on the matrices of rank 1. Hence any invertible linear transformation on matrices that preserves the rank-1 set over R will automatically do the same over all extensions of R. Similarly, the linear combinations of 4 × 4 Paffians are the only quadratic forms vanishing on the alternating matrices of rank 2. Hence again any invertible transformation preserving that set over R will do so formally. This fact allows us to determine the collection of such transformations 相似文献
69.
Canonical forms are given for complex quadric surfaces (and conics) under real changes of variable. The basic idea is to use known results on pairs of real quadratic forms. 相似文献
70.
William C. Waterhouse 《Journal of Pure and Applied Algebra》1976,7(2):121-132
This paper is a self-contained introduction to a theory of higher differential algebra. The results were originally accumulated in sporadic attempts to forge a link between differential algebra and the study of formal groups, and one trace of that goal is included here as motivation. Primarily, however, the theory is of interest because it preserves for arbitrary rings much of the formal structure of ordinary differential algebra for Ritt algebras. Some of the results have appeared in weaker form in the literature, so it seems worthwhile to put the theory on record. 相似文献