The relation between the socalled Coriolis couplingI · j, operating in rotating nuclei, and the classical Coriolis force is discussed. The system forces acting in the cranking model for non-uniform rotation and in the rotator-particle model are examined. Differences with the molecular Coriolis coupling are indicated. 相似文献
Terminal alkynols react with formaldehyde and secondary amines in aqueous ionic liquid [emim]HSO–4 in the presence of Cu(OAc) to afford the corresponding 1-(a-hydroxyalkyl)- or 1-(b-hydroxyalkyl)-2-(aminomethyl)acetylenes in better yields in comparison with the reaction in conventional organic solvents. The catalytic system can be easily recovered and recycled. 相似文献
Abstract Two imino(bismethylene)phosphat-ions can be synthesized via reaction of phenylamino- and α-naphthylaminobismethylenephosphorane with n-butyllithium in tetrahydrofuran. Anions containing [sgrave]3λ6-bounded phosphorus are stabilized in the crystal with THF-solvated lithium-kations. Zwei Imino(bismethylen)phosphat-ionen werden durch Umsetzung des Phenylamino- und des α-Naphthylaminobismethylenphosphorans mit n-Butyllithium in Tetrahydrofuran erhalten. Die Anionen mit [sgrave]3λ6-gebundenem Phosphor werden im Kristall durch THF-solvatisierte Lithium-Kationen stabilisiert. 相似文献
The very strong Lewis acid aluminium chlorofluoride (ACF) was loaded with anhydrous HF. The interaction between the surface of the catalyst and HF was investigated using a variety of characterization methods, which revealed the formation of polyfluorides. Moreover, the reactivity of the HF-loaded ACF towards the hydrofluorination of alkynes was studied. 相似文献
A novel strategy for the automation of trace lead (Pb2+) and cadmium (Cd2+) anodic stripping voltammetry (ASV) is described. This was achieved using an electrode assembly comprising a small standard reference electrode, a Pt wire counter electrode, and an in situ bismuth-plated pencil lead working electrode for ASV in a robotic device adapted for measurements in a 24-well microtiter plate format. The movement of the electrode assembly through individual wells was by computer-controlled micropositioning, and each microtiter plate run included a sequence of electrode pretreatment, water rinsing, and simultaneous Pb2+ and Cd2+ ASV measurements. Analyte concentrations down to 2 μg/L (Pb2+) and 20 μg/L (Cd2+) could be measured in drinking and tap water, a wastewater reference material and a soil sample, with an accuracy and standard deviation typical of stripping analysis. This robotic electrochemical strategy offers automated trace metal analysis with simple instrumentation and is suggested as an option for routine use in analytical laboratories such as those providing environmental heavy metal testing services. 相似文献
Designing three‐dimensional (3D) scaffolds for selective manipulation of cell growth is of high relevance for applications in regenerative medicine. Especially, scaffolds with oriented morphologies bear high potential to guide the restoration of specific tissues. The fabrication of hydrogel scaffolds that support long‐term survival, proliferation, and unidirectional growth of embedded cells is presented here. Parallel channel structures are introduced into the bulk hydrogels by uniaxial freezing, providing stable, and uniform porosity suitable for cell invasion (pore diameters of 5–15 µm). In vitro assessment of the scaffolds with murine fibroblasts (NIH L929) shows a remarkable unidirectional movement along the channels, with the cells traveling several millimeters through the hydrogel.