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1.
Microring resonator channel dropping filters 总被引:17,自引:0,他引:17
Little B.E. Chu S.T. Haus H.A. Foresi J. Laine J.-P. 《Lightwave Technology, Journal of》1997,15(6):998-1005
Microring resonators side coupled to signal waveguides provide compact, narrow band, and large free spectral range optical channel dropping filters. Higher order filters with improved passband characteristics and larger out-of-band signal rejection are realized through the coupling of multiple rings. The analysis of these devices is approached by the novel method of coupling of modes in time. The response of filters comprised of an arbitrarily large dumber of resonators may be written down by inspection, as a continued fraction. This approach simplifies both the analysis and filter synthesis aspects of these devices 相似文献
2.
Bruce J. West Raoul Kopelman Katja Lindenberg 《Journal of statistical physics》1989,54(5-6):1429-1439
The conditions for macroscopic segregation ofA andB in a steady-stateA+B 0 reaction are studied in infinite systems. Segregation occurs in one and two dimensions and is marginal ford=3. We note the dependence of these results on the precise experimental conditions assumed in the theory. We also note the difference between these results and our earlier ones for finite systems where the critical dimension isd=2. 相似文献
3.
The relation between the aperiodic solution of the Lorenz model and that of a stochastic anharmonic oscillator is explored. The stochastic oscillator is constructed by replacing (t) in the Lorenz model by a stochastic variable(t) of specified statistics. The resulting system is of course not isomorphic to the Lorenz model, but does share with it a number of statistical properties. Thus, within the confines of these measures the two systems are physically very similar. 相似文献
4.
Nonlinear systems with stochastic parameters are approximated by simpler systems using a method that we call statistical replacement. This method is an extension of the previously developed AGREE which was restricted to systems with additive fluctuations. Statistical replacement incorporates the distinctions between globally stable thermodynamically closed systems and thermodynamically open systems that can be unstable. 相似文献
5.
We consider the equation \(\rm f^{\prime\prime}+{A}(z){f}=0\) with linearly independent solutions f1,2, where A(z) is a transcendental entire function of finite order. Conditions are given on A(z) which ensure that max{λ(f1),λ(f2)} = ∞, where λ(g) denotes the exponent of convergence of the zeros of g. We show as a special case of a further result that if P(z) is a non-constant, real, even polynomial with positive leading coefficient then every non-trivial solution of \(\rm f^{\prime\prime}+{e}^P{f}=0\) satisfies λ(f) = ∞. Finally we consider the particular equation \(\rm f^{\prime\prime}+({e}^Z-K){f}=0\) where K is a constant, which is of interest in that, depending on K, either every solution has λ(f) = ∞ or there exist two independent solutions f1, f2 each with λ(fi) ≤ 1. 相似文献
6.
The major octabromo isomer of technical octabromo diphenyl ether mixture (technical octaBDE) DE-79 was isolated by RP-HPLC. Three serially coupled columns (each 250 mm long) enabled a good separation of the target compound from other congeners using 100% ACN as eluent. Approximately 100 microg of the target compound was isolated with a purity of >90% and investigated by MS for confirmation of the degree of bromination. 1H-NMR and 2-D 1H-13C correlation NMR spectra unequivocally clarified that the octaBDE in question is 2,2',3,3',4,4',6,6'-octabromodiphenyl ether (BDE 197). Based on annual production rates of technical BDE products (1999/2001), approximately 380 tons of BDE 197 were annually produced which, on the long term, may enter the environment. Compared with other individual BDE congeners, BDE 197 has the seventh highest application rate. Reductive debromination of BDE 197 can lead to four hepta-, 15 hexa-, 23 penta-, and 28 tetra-BDE isomers, respectively. This variety includes all known major BDEs of environmental concern (BDE 47, 85, 99, 100, 153, 154, and 183). The identification of BDE 197 in technical octaBDE DE-79 strongly suggests that research on the environmental fate of BDEs should include this key-BDE congener. 相似文献
7.
Flowers of Jasminum rincospernum convert deuterium-labeled jasmonic acid [2H5]- 4a and methyl 1,2-didehy-drojasmonate [2H4]- 8 into labeled cis-jasmone [2H4]- 1. The labeling pattern of the resulting cis-jasmone ( 1 ) is consistent with a Grob fragmentation of the didehydrojasmonic acid 8a by decarboxylation after protonation of the keto group. The pathway is also operative in leaves of several higher plants, including mono- and dicotyledonous specimens. In Lima beans besides cis-jasmone ( 1 ) an equimolar mixture of trans- and cis-isomers of methyl jasmonate ( 4 ) and epi- 4 , is emitted after treatment with Jasmonic acid ( 4a ). The relative ratio of 1 and 4 /epi- 4 is critically dependent on the concentration of the administered jasmonic acid ( 4a ) and the ambient temperature of the plant. Unlike 4a , the 1,2-didehydrojasmonic acid ( 8a ) is not able to induce volatile biosynthesis. Therefore, the transformation of 4a via 8 a into 1 appears to have a special importance for the irreversible inactivation and disposal of the plant stress hormone jasmonic acid to the gas phase and may serve, besides other modes of inactivation, as a shunt in case of high internal of the stress hormone 4a. The conversion of the biologically active jasmonic acid ( 4a ) into the inactive and volatile cis-jasmone (1) is the first example of a disposal of an inactive metabolite of a phytohormone to the gas phase as an infinite sink. 相似文献
8.
Bond AD García F Jantos K Lawson GT McPartlin M Wright DS 《Chemical communications (Cambridge, England)》2002,(12):1276-1277
The novel, deca-lithium cage [(mtaNHLi)(As2(Nmta)5)-Li(4).2thf]2 (1) (mtaN = 5-methylthiazolyl, C4H4N2S) contains an imido-bridged tetraanion [(mtaN)2As(mu-Nmta)-As(Nmta)2]4-, which represents a new type of multi-functional imido group 15 ligand framework (homologous with group 15 anions of the type [As(NR)3]3-). 相似文献
9.
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