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1.
Interaction of α,ω-dihaloalkanes with sulfide ion (eq. 1) is a common route for the synthesis in good yield of 5- and 6-membered polymethylene sulfides. 相似文献
2.
3.
Nélio Drumond André Sá Couto Ana Costa Helena Cabral-Marques 《Journal of inclusion phenomena and macrocyclic chemistry》2014,80(1-2):25-30
The aim of this study was to investigate the influence of different cyclodextrins (CyD) on physical characteristics of inhalation dry powders. The particle size was characterised by Aerosizer® LD and aerodynamic behaviour of inhaled complexes assessed by twin-stage liquid impinger. The in vitro release profile of the powders was studied through Franz cell modified method. Produced particles showed a suitable size for pulmonary delivery, ranging between 1 and 5 μm. The nature of the CyD affected the powders performance on reaching the lower compartment (“Lungs”), mainly by the altering their aerodynamic properties, which is reflected on the different percentages of their emitted respirable fractions. HP-γ-CyD:fluticasone propionate complex showed a fast release of corticosteroid while γ-CyD had a constant release throughout time. The best characteristics for pulmonary delivery were obtained with acetyl-γ-CyD:fluticasone propionate complex. 相似文献
4.
F. J. Baltá Calleja D. R. Rueda T. Secall R. K. Bayer M. Schlimmer 《Journal of Macromolecular Science: Physics》2013,52(4):461-469
Native potato starch was prepared using different processing methods. The samples were characterized by wide-angle X-ray scattering (WAXS), optical microscopy, differential scanning calorimetry (DSC), and microhardness. Compression molding of the starch granules led to sintered relatively brittle materials. Here, the amylopectin crystals of the native powder remained grossly preserved. Preparation of dry films from aqueous gels resulted in disintegration of the structure of the native starch granules and in the formation of a new semicrystalline structure comprised of crystallized amylose molecules. Injection molding of native starch was found to be a processing method that gives rise to amorphous materials with superior mechanical properties. 相似文献
5.
Jana Špaková Raschmanová Miroslava Martinková Jozef Gonda Alena Uhríková 《Chemical Papers》2013,67(10):1317-1329
The stereoselective synthesis of sulfamisterin I and its unnatural analogues II and V in their protected form was achieved through a common strategy. The Wittig reaction of aldehydes VIII and IX with the C14 hydrophobic side-chain X served as the key C-C connecting transformation. Subsequent functional group inter-conversions in the coupling products XI and XX completed the total synthesis. 相似文献
6.
Tomá? Weidlich Anna Krej?ová Lubomír Proke? 《Monatshefte für Chemie / Chemical Monthly》2010,9(4):1015-1020
Abstract
Dehalogenation of halogenated anilines by action of powdered aluminium–nickel alloy in aqueous alkaline solution at room temperature has been studied. The reaction course was monitored by means of 1H nuclear magnetic resonance (NMR) spectroscopy. The rates of dehalogenation of 4-bromo-, 4-chloro-, 4-fluoro- and 3-chloroaniline were compared under conditions of minimum necessary excess of Al–Ni alloy as reducing agent in edetane buffer medium at pH 10.9. The dehalogenation rates of halogenated anilines decreased in the following order: 3-chloroaniline > 4-bromoaniline ≥ 4-chloroaniline > 4-fluoroaniline. On the basis of the results obtained in buffers, the dehalogenation method of aqueous solutions of halogenoanilines was verified using NaOH as the base. 相似文献7.
8.
The inhibition of the oxygen evolution rate (OER) in Chlorella vulgaris by 2-alkylsulphanyl-4-pyridinecarbothioamides (APCTs; alkyl = methyl up to hexadecyl) was studied. APCTs were found to inhibit
photosynthetic electron transport (PET) which resulted in the inhibition of OER in algae. The inhibitory activity of APCTs
was highly dependent on the alkyl chain length of the 2-alkylsulphanyl substituent and the corresponding dependence showed
a bilinear course with the decyl derivative as being the most active inhibitor. Using EPR spectroscopy, the site of APCT action
in the algal photosynthetic apparatus was determined. It was confirmed that APCT interacted mainly with the D. intermediate,
i.e. with tyrosine radical (TyrD) occurring at the 161st position in D2 protein which is situated on the donor side of photosystem 2. 相似文献
9.
Trajectory planning is a well-known open-loop control strategy to minimize residual vibrations in point-to-point tasks of systems featuring mechanical flexibility. However, the major drawback of open-loop control is its limitation in coping with modeling uncertainty. In this paper a novel approach to trajectory planning based on LQR theory is proposed and applied to a single flexible link robot. To improve performance under parameter uncertainty the strategy is combined with collocated vibration control through piezoelectric actuation of the link. This combination raises the issue of the roles and the contribution of each actuator type to the overall performance of the maneuver. An actuator specialization is proposed where the joint controller is responsible for the gross vibrationless motion of the link, while the link actuators are expected to deal only with residual vibrations that may arise from modeling errors. Simulation and experimental results validate the trajectory planning methodology and the combination of the open-loop strategy with collocated vibration control. 相似文献
10.
Alicia Godoy Linda Cattin Jean Christian Bernède Fernando Díaz Mará Angélica del Valle 《Macromolecular Symposia》2011,304(1):109-114
Summary : Perylene derivatives, that behave as liquid crystal and might be used as electron acceptors, and poly(tetrabromo-p-phenylenediselenide) (PTBrPDSe) were synthesized with the purpose of using the polymer as buffer layer in solar cells. It was demonstrated that perylene compounds of N,N′-diheptyl-3,4,9,10-perylentetracarboxyldiimide (PTCDI-C7) and N,N′-diundecyl-3,4,9,10-perylentetracarboxyldiimide (PTCDI-C11) enabled obtaining photovoltaic effect when coupled with copper phthalocyanine (CuPc). The power conversion efficiency of the cells prepared from these perylenes is similar, whatever the x value. However this efficiency is smaller than the one achieved when the couple CuPc/C60 (fullerene) is used. More precisely, the best efficiency was obtained when a PTBrPDSe/Au buffer layer is introduced between the ITO anode and the CuPc. It was established that the presence of the thin PTBrPDSe layer allows improving the shunt resistance and consequently the cells performance. 相似文献