Ultrafast Internal Conversion Dynamics of 2-Chloropyridine by Femtosecond Time-Resolved Photoelectron Imaging

Ultrafast internal conversion dynamics of 2-chloropyridine were studied by femtosecond time-resolved photoelectron imaging spectroscopy coupled with time-resolved mass spectroscopy. The ultrafast internal conversion from the second excited state (S2) to the first excited state (S1) via an adjacent conical intersection within (162±5) fs was clearly observed from the time-dependence of the photoelectron spectra. The subsequent deactivations involved the coupling of S2/S0(the ground state) and S1/S0 conical intersections, which occurred on a timescale of about (5.5±0.3) ps, and led to the internal conversion to the ground state from the S2 and S1 states.     

Dendritic growth and solute trapping in rapidly solidified Cu-based alloys

Rapid solidification of binary Cu-22%Sn peritectic alloys and Cu-5%Sn-5%Ni-5%Ag quaternary alloys was accomplished by glass fluxing, drop tube and melt spinning methods. The undercooled, by glass fluxing method, Cu-22%Sn peritectic alloy was composed of α(Cu) and δ(Cu41Sn11) phases. If rapidly solidified in a drop tube, the alloy phase constitution changed from α(Cu) and δ(Cu41Sn11) phases into a single supersaturated (Cu) phase with the reducing of droplet diameter, and the maximum solubility of Sn in (Cu)...     

Synthesis of the Complex Fluoride LiBaF_3 through a Solvothermal Process

The complex fluoride LiBaF3 is solvothermally synthesized at 180℃ and characterized by means of X-ray powder diffraction, scanning electron microscopy, thermogravimetric analysis and infrared spectroscopy. In the solvothermal process, the solvents, mole ratios of initial mixtures and reaction temperature play important roles in the growth of the single crystal.     

Two New Triterpenoid Glycosides from Elsholtzia bodinieri Vant

Elsholtzia bodinieri Vant (Labiatae) named Feng-Wei-Cha or Dong-Zi-Su, is a Chinese medicinal plant, which is distributed in Yunnan and Guizhou Province of China. It is used in treatment of cough, headache, pharyngitis, fever and heptatitis1. In order to seek for the relative bioactive components, we studied the chemical constituents of E. bodinieri, which have not been reported in the literature. Two new triterpenoid glycosides, hederagenin-3-O-b-D-xylopyranoside (1), dodecandral-3-O…     

A Peptide—mediated Fenton Reaction in Wood—degrading Fungi

Cellulose is the most abundant resource of regenerative biomass on earth. But due to the complexity of its structure, its degradation mechanism was failed to fully understand. It makes a great limit to its full utility. In nature, wood decay is mainly accomplished by some wood-degrading fungi such as G.trabeum et al.. It is well-known that cellulases are the most important components of degrading cellulose. But because the cellulase activity is low, the complete utility of cellulose by e…     

Synthesis of a New Family of Green Light Emitting Material Containing Both Hole and Electron Transporting Units

Since Tang and Van Slyke reported the first double-layer organic electroluminescent (EL) device using Alq3 (q = 8-hydroxyquinolinyl) in 19871, organic EL devices have received a great deal of attention in view of their application as full-color flat-panel displays as well as academic interest2,3,4. There have been extensive studies of organic EL devices directed toward achieving high brightness and multi- or full-color emission, and in particular, improving the durability and thermal stabi…     

BINARY NONLINEARIZATION FOR THE DIRAC SYSTEMS

ＢＩＮＡＲＹＮＯＮＬＩＮＥＡＲＩＺＡＴＩＯＮＦＯＲＴＨＥＤＩＲＡＣＳＹＳＴＥＭＳＭＡＷＥＮＸＩＵＡｂｓｔｒａｃｔＡＢａｒｇｍａｎｎｓｙｍｍｅｔｒｙｃｏｎｓｔｒａｉｎｔｉｓｐｒｏｐｏｓｅｄｆｏｒｔｈｅＬａｘｐａｉｒｓａｎｄｔｈｅａｄｊｏｉｎｔＬａ...     

A Durable Catalyst for Vapor Phase Nitration of Benzene with Nitric Acid

Nitrobenzene is one of the most important chemical intermediates, for preparing drugs, pesticides and explosive etc. For more than a century, it has been commercially manufactured by reacting benzene with mixed acid in liquid phase under vigorous agitation. Despite the high efficiency, the mixed-acid process has some drawbacks, among which the huge amount of spent acid and wastewater are by far the most crucial, and this makes an alternative solution desirable. Nitration of benzene over sol…