Samarium(II) diiodide mediated intramolecular cyclisation of mixed enone-enoate substrates in THF/MeOH is described. Spirocyclic ethers are obtained, and the stereodefined preparation of 1-oxaspiro[4.4]nonan-7-one products is included. 相似文献
We reported an interfacial self-assembly of regularly layered porous poly(4-vinylpyridine)(P4VP) films at the interfaces of water-chloroform or -dichloroethane.The porous diameters were in the range from hundred nanometers to several micrometers.It was revealed that formation of such kind of porous materials was solvent dependent.Moreover,cyclic Ag nanoparticles could be grown in the porous P4VP films to form Ag-P4VP nanohybrids under radiation. 相似文献
Two series of novel tolane-type liquid crystals(LCs) comprising of hydrogen-bonded organic acids were synthesized.The formation of dimerized H-bond LCs was confirmed by IR spectroscopy,and mesomorphic properties of the LCs were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).It was found that the end groups of the liquid crystals as well as the unsaturated rigid core had effect on the mesomorphic properties. 相似文献
A high-performance liquid chromatographic method has been developed for the simultaneous analysis of the flavonols myricitrin (1), avicularin (2), and juglanin (3) in rat plasma and urine after oral administration of the total flavonoids from Polygonum aviculare. Samples were prepared by solid-phase extraction then separated on a C18 reversed-phase column by use of a mobile-phase gradient prepared from methanol and aqueous formic acid solution. The flow rate was 1 mL min−1. Detection was performed at 254 nm. The calibration range was 11–1,100 μg mL−1 for both 2 and 3 in plasma; in urine the calibration ranges for 1, 2, and 3 were 32–1,600, 11–1,100, and 22–1,100 μg mL−1, respectively. Intra-day and inter-day RSD were less than 4.33 and 3.62% for 2 and 3, respectively, in plasma, and no more than 4.03 and 2.22% for all the analytes in urine. The analytical sensitivity and selectivity of the assay enabled successful application to pharmacokinetic studies of flavonols 1–3 in rats.
JavaStatSoft, implemented using Java, is an open-source software for performing statistics. The current features of JavaStatSoft
are described. Several well-known patterns the software used are introduced. In addition, based on these patterns and the
experience in developing the software, a new framework, referred to as Data Analysis Module, is proposed to help programmers
develop a user-friendly software for data analysis. 相似文献
Based on a fictitious market model, a decentralized approach is presented for the workstation scheduling in a CNC workshop. A multi-agent framework is proposed, where job agents and resource agents act as buyers and sellers of resource in the virtual market. With cost and benefit calculation of these agent activities, which reflects the state of the production environment, various, and often conflicting goals and interests influencing the scheduling process in practice can be balanced through a unified instrument offered by the markets. The paper first introduces a heuristic procedure that makes scheduling reservations in a periodic manner. A multi-agent framework is then introduced, in which job agents and resource agents seek appropriate job–workstation matches through bidding in the construction of the above periodic “micro-schedules”. A pricing policy is proposed for the price-directed coordination of agent activities in this. Simulation results demonstrate the feasibility of the proposed approach and give some insights on the effects of some decision making parameters. Future work will be focused on the designing of some more sophisticated coordination mechanism and its deployment. 相似文献
Vacuum-prepared multi-layer Cu films have been studied by x-ray diffraction to detect the averaged dislocation density and distribution. There are very few stacking faults and a very small degree of texture in the films. 相似文献