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381.
We study the stability of a robot system composed of two Euler–Bernoulli beams with non-collocated controllers. By the detailed spectral analysis, we prove that the asymptotical spectra of the system are distributed in the complex left-half plane and there is a sequence of the generalized eigenfunctions that forms a Riesz basis in the energy space. Since there exist at most finitely many spectral points of the system in the right half-plane, to obtain the exponential stability, we show that one can choose suitable feedback gains such that all eigenvalues of the system are located in the left half-plane. Hence the Riesz basis property ensures that the system is exponentially stable. Finally we give some simulation for spectra of the system. 相似文献
382.
383.
Jia‐Jian Wang Hua‐Ming Zeng Zhi‐Gang She Cheng‐Du Miao Kui Hong Yu‐Cheng Gu Lan Liu Yong‐Cheng Lin 《Helvetica chimica acta》2011,94(10):1875-1880
Two new meroterpenes, ‘acetoxydehydroaustin B’ ( 1 ) and ‘1,2‐dihydro‐acetoxydehydroaustin B’ ( 2 ) were isolated in the form of a mixed crystal from the mangrove endophytic fungus Aspergillus sp. 085241B. Their structures and absolute configurations were determined by extensive analysis of their spectra and X‐ray diffraction data. In a preliminary bioassay, the mixed crystal did not exhibit activities against cancer cell lines of MDA‐MB‐435, SKBR3, HepG2, HEP3B, PC‐3, and A549, as well as against α‐glucosidase and tyrosinase. 相似文献
384.
Lan Yao Gregory O. Andreev Yana K. Reshetnyak Oleg A. Andreev 《Analytical and bioanalytical chemistry》2009,395(5):1563-1566
We demonstrate the feasibility of fabrication of semiconducting nanowires (quantum dots) using F-actin as a template. Three
different approaches of assembling quantum dots into nanowires are described. The nanowires were characterized by fluorescence
microscopy. 相似文献
385.
386.
α-Oxo Ketene Dithioacetals Chemistry-A Facile Route to the Synthesis of Fused Heterocyclic Compounds
Q-Oxo ketene dithioacetals and related compounds are versatile synthons in organicsynthesis'-'. The substitution reaction of or-oxo ketene dimethylthio acetals with diamineis one of the impel'tant applications for the synthesis of corresponding a-oxo ketenecyclic N, N-acetals. Junjappa and co-workers described this reaction ill a review'.However, since some kinds of ketene dimethylthio acetals are not easy to prepare, themethod melltioned above is limited. Zhu and co-workers had successfully… 相似文献
387.
Li Gaoliang He Hui Zheng Weifang Tang Hongbin Li Huirong Lan Tian Liu Xiechun Zhang Hu Yang He Luo Fangxiang Xiao Songtao Ye Guoan 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(1):279-284
Oxidation of Pu(III) in 1 bp solution to Pu(IV) was studied using the salt-free oxidant N2O4. It was proved that the reductants N,N-dimethylhydroxylamine (DMHAN) and monomethyl-hydrazine (MMH) present in 1 bp solution of CIAE-APOR process can be oxidized and removed from the solutions also by N2O4 before the oxidation of Pu(III). The effects of the acidity, the temperature and the amount of N2O4 added on the oxidation of DMHAN and MMH were studied. 相似文献
388.
389.
Xuening Fei Yingchun Gu Yunquan Lan Bin Shi Baolian Zhang 《Journal of chemical crystallography》2011,41(8):1232-1236
Abstract
The title compound of Thiazole Orange derivative was synthesized by the reaction of benzothiazolium and 4-methyl quinoline salts, which was determined by 1HNMR and MS. A crystalline hydrate of thiazole orange derivative was obtained when the crystal formed and characterized by single-crystal X-ray diffraction. The crystal belongs to the Triclinic system, and the cell parameters of space group P-1 were a = 10.162(2) ?, b = 10.501(2) ?, c = 11.040(2) ?, α = 92.17(3)o, β = 117.10(3)o, γ = 92.28(3)o, V = 1045.9(4) ?3, Z = 2, Dc = 1.380 mg/m−3, μ = 0.2 mm−1, F(000) = 460, and the final R = 0.0625 and wR = 0.1862 for 3658 observed reflections (I > 2σ(I)). The two aromatic rings linked by the methylene bridged chain are a coplanar structure. 相似文献390.
Jen‐Taut Yeh Chi‐Hui Tsou Wei Lu Ya‐Ming Li Han Wen Xiao Chi‐Yuan Huang Kan‐Nan Chen Chin‐San Wu Wan‐Lan Chai 《Journal of Polymer Science.Polymer Physics》2010,48(9):913-920
Fourier transform infrared and nuclear magnetic resonance results suggest that the carboxylic acid groups of poly(lactic acid) (PLA) molecules react with the hydroxyl groups of FePol (FP) molecules during the melt‐blending of PLAxFPy specimens. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) experiments of PLA and PLA/FP specimens suggest that only small amounts of poor PLA and/or FP crystals are present in their corresponding melt crystallized specimens. In fact, the percentage crystallinity, peak melting temperature, and onset re‐crystallization temperature values of PLA/FP specimens reduce gradually as their FP contents increase. However, the glass transition temperatures of PLA molecules found by DSC and DMA reduce to a minimum value as the FP contents of PLAxFPy specimens reach 6 wt %. Further DMA and morphological analysis of PLA/FP specimens reveal that FP molecules are compatible with PLA molecules at FP contents equal to or less than 6 wt %, as no distinguished phase‐separated FP droplets and tan δ transitions were found on fracture surfaces and tan δ curves of PLA/FP specimens, respectively. In contrast to PLA, the FP specimen exhibits highly deformable and tearing properties. After blending proper amounts of FP in PLA, the inherent brittle deformation and poor tearing behavior of PLA were successfully improved. Possible reasons accounting for these interesting crystallization, compatible and tearing properties of PLA/FP specimens are proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 913–920, 2010 相似文献