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931.
Controller design methods based on flatness and passivity are well established. These methods are applied to PCHD systems such that flatness is used to achieve a high tracking performance and passivity ensures disturbance rejection and robustness. Since the error system, written in displacement coordinates, is not a PCHD system in general, we present conditions, which ensures this property. Therefore, one can apply methods from passivity control to stabilize the error dynamics. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
932.
[{Cp*(CO)2Fe}6Sn6O8]2+, a Cationic Tin Oxo Cluster with Organometallic Substituents The reaction of [{Cp*(CO)2Fe}SnCl3] 1 (Cp* = Pentamethylcyclopentadienyl) with Ag2O in acetone leads to the formation of [{Cp*(CO)2Fe}6Sn6O8][AgCl2]2( 2 ). 2 contains the novel tin oxo cluster cation [{Cp*(CO)2Fe}6Sn6O8]2+ which consists of six {Cp*(CO)2Fe}Sn‐groups bridged by eight μ3 oxygen atoms (Sn—O = 209.2(3)‐212.5(3) pm). The resulting Sn6O8 cage exhibits a distorted rhombodocahedral structure. The [AgCl2]— anion is essentially linear with a Ag—Cl bond length of 250.3(3) pm. 相似文献
933.
Angela I. Caldern Christian Terreaux Mahabir P. Gupta Kurt Hostettmann Kurt J. Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):o174-o176
(2R)‐α‐(β‐d ‐Glucopyranosyloxy)‐4‐hydroxybenzeneacetonitrile (taxiphyllin) dihydrate, C14H17NO7·2H2O, is a naturally occurring cyanogenetic glycoside which has been isolated from Henriettella fascicularis (Sw.) C. Wright (Melastomataceae). Its structure is stabilized by a wealth of intermolecular O—H⃛O and O—H⃛N hydrogen bonds spun into a three‐dimensional network. Further stabilization arises from an intramolecular O—H⃛O bond and weak intermolecular C—H⃛O interactions. The very anisotropic growth speeds of the basal pinacoids from methanol mirror a certain structural inhomogeneity. 相似文献
934.
935.
936.
Lithiated Phosphoraneimine Complexes. Crystal Structures of [LiCH(Me)PEt2NSiMe3]4 and of Cuprate [Li{Me3SiNPMe2CH2–Cu–CH(SiMe2OLi)PMe2NSiMe3}]2 [LiCH(Me)PEt2NSiMe3]4 ( 1 ) has been obtained as colorless, oxygen and moisture sensitive crystals from the reaction of the silylated phosphoraneimine Me3SiNPEt3 with nbutyllithium in nhexane at 0 °C. 1 crystallizes in the tetragonal space group I41/acd with eight formula units per unit cell. Lattice dimensions at –80 °C: a = b = 1505.2(1), c = 4747.4(6) pm, R1 = 0.0278. 1 forms a Li4 tetrahedron, the faces of which are capped with the carbon atoms of the carbanionic ‐CH(Me)‐ groups. The nitrogen atoms occupy the corners of the Li4 tetrahedron by means of “inner solvation”. The cuprate [Li{Me3SiNPMe2CH2–Cu–CH(SiMe2OLi)PMe2NSiMe3}]2 ( 4 ) has been obtained from the known [LiCH2PMe2NSiMe3]4 and copper(I) iodide in the presence of silicon grease (‐OSiMe2‐)n in diethylether, forming colorless oxygen and moisture sensitive crystals. 4 crystallizes in the triclinic space group P 1 with one formula unit per unit cell. Lattice dimensions at –50 °C: a = 1025.4(2), b = 1145.5(2), c = 1261.0(2) pm, α = 65.19(1)°, β = 79.55(1)°, γ = 77.94(1)°, R1 = 0.039. 4 forms a centrosymmetric dimeric molecule with a central Li2O2 four‐membered ring, the oxygen atoms of which are connected by ‐SiMe2‐ bridges with the cuprate fragment > CH–Cu–CH2‐. 相似文献
937.
Raman spectroscopic and 35Cl‐NMR scans of Hydro‐Xan®, a preparation containing the biocatalytically effective Tetrachlorinedecaoxide anion (TCDO), are described. The spectroscopic analyses showed that HydroXan® does not contain chlorite initially used in the preparation anymore. Furthermore, a structure of four equal chlorate‐like ClO3‐groups was indicated for TCDO by the scans. Such a structure is supported by the long‐term stability of HydroXan® found at tests over 267 days. 相似文献
938.
Diacetone Alcohol Complexes of Lanthanide Trichlorides. Crystal Structures of [LnCl3(DAA)2] with Ln = Sm and Eu The diacetone alcohol complexes [LnCl3(DAA)2] with Ln = samarium ( 1 ) and europium ( 2 ) are obtained from the waterfree metal trichlorides with excess diacetone alcohol (4‐hydroxy‐4‐methyl‐2‐pentanone = DAA) forming colourless ( 1 ) and pale yellow crystals ( 2 ), respectively, which are characterized by crystal structure determinations. The europium compound 2 is additionally described by its vibrational spectra (IR, Raman). 1 and 2 crystallize isotypically with one another. The metal atoms of the molecular complex units are unusually coordinated in a distorted pentagonal‐bipyramdial fashion by the three chlorine atoms and by the two alcoholic oxygen atoms of the DAA molecules in the equatorial plane. The apical positions are occupied by the carbonyl oxygen atoms of the chelating DAA molecules. The complex units [LnCl3(DAA)2] are associated along [100] by bifurcated —OH···Cl···HO— bridges to form chains. 1 : Space group P21, Z = 2, lattice dimensions at —80 °C: : a = 710.2(1), b = 1617.6(2), c = 827.3(1) pm; β = 106.36(1)°; R1 = 0.026. 2 : Space group P21, Z = 2, lattice dimensions at —80 °C: a = 709.7(1), b = 1614.5(2), c = 825.7(1) pm; β = 106.40(1)°; R1 = 0.0303. 相似文献
939.
Reiner Weichert Walter Klemm Kurt Legenhausen Claudia Pawellek 《Particle & Particle Systems Characterization》2002,19(3):216-222
Biological aerosols like pollen or bacteria can be differentiated from non‐biological aerosols as dust by fluorescence. Several organic substances contained in biological particles emit fluorescence light if they are illuminated with ultraviolet light. An instrument has been developed which generates aerosols of individual bacteria, illuminates them with light in the range of wavelengths from 220 to 570 nm and detects the spectra of fluorescence. The instrument has been tested on different species of bacteria showing that their fluorescence spectra are different. 相似文献
940.
Structures of cyclic 2‐(3‐oxo‐3‐phenylpropyl)‐substituted 1,3‐diketones 4a – c were determined by 17O‐NMR spectroscopy and X‐ray crystallography. In CDCl3 solution, compounds 4a – c form an eight‐membered‐ring with intramolecular H‐bonding between the enolic OH and the carbonyl O(11)‐atom of the phenylpropyl group, as demonstrated by increased shielding of specifically labeled 4a – c in the 17O‐NMR spectra (Δδ(17O(11))=36 ppm). In solid state, intermolecular H‐bonding was observed instead of intramolecular H‐bonding, as evidenced by the X‐ray crystal‐structure analysis of compound 4b . Crystals of compound 4b at 293 K are monoclinic with a=11.7927 (12) Å, b=13.6230 (14) Å, c=9.8900 (10) Å, β=107.192 (2)°, and the space group is P21/c with Z=4 (refinement to R=0.0557 on 2154 independent reflections). 相似文献