Synthesis and fluorescence properties of dysprosium‐coordinated with high‐Tg polyaryletherketones containing carboxyl side groups

A series of novel dysprosium coordination polymers were synthesized using new high‐T_g carboxyl‐containing polyaryletherketones (PEKs) as macromolecular ligands and a small molecule, 1,10‐phenanthroline, as co‐ligand. The FTIR, WAXD, and UV–Vis results indicated that the dysprosium ions were coordinated simultaneously with carboxyl group of PEKs and 1,10‐phenanthroline, and homogeneously distributed along the polymer backbone. These obtained dysprosium coordination polymers showed excellent film‐formation properties. Moreover, all the dysprosium coordination polymers could exhibit the intense characteristic emission of dysprosium ions under UV excitation. Meanwhile, the emission intensity increased with increasing dysprosium ion content, and no obvious fluorescence quenching happened at the Dy³⁺ ion content up to 10.71 wt%, which was attributed to the very rigid structure of PEK and synergistic coordination effect of PEK and 1,10‐phenanthroline. Copyright © 2009 John Wiley & Sons, Ltd.     

Gnetifolin L and O, Two Dimeric Stilbenes from Gnetum Montanum

GnetuI)1monlanlImgr0wsinthes0uthernpart0fChinaandhasbeenusedf0rthetreatment0fbronchitisandarthritisinf0lkmedicinel.Previously,aninvestigationofthisspeciesledt0theis0lationofs0meaIkal0idsanddibenzyletherderivatives2.lnourstudies,tenc0mp0nentsincludingresveratr0l,is0rhapontigenin,daucoster0l,O-sitosterol,stearicacid,gnetif0linE,gnet0l,is0rhapontigenin-3-O-6-gluc0pyra(-)8-viniferinandgnetifolinCwere0btainedfromthisplant'.Inthefurtherstudy,f0urnewdimericstilbenesnamedgnetif0IinMandN',gnetifoli…     

A stage-structured predator–prey model with disturbing pulse and time delays

In this article we propose a stage-structured predator–prey model with disturbing pulse and time delays and obtain the sufficient conditions for the global attractivity of predator-eradiation periodic solution and permanence of the system. We also show that time delay, pulse catching rate and the period of pulsing can affect the dynamics of the system.     

Time‐resolved spectroscopy study of donor–acceptor‐type copolymers in a monodisperse system: The effect of ratio between the acceptor and the donor

The photoexcitation processes of two donor–acceptor‐type copolymers PCFBT with different ratios between the donor and the acceptor ( PCFBT_0.5 and PCFBT_0.1 ) in the solution system are systematically studied. If the number of the donor is equal to that of the acceptor in one repeat unit (such as PCFBT_0.5 ), intrachain charge transfer (ICT) can occur and participate in the relaxation of the excited state after photoexcitation. When the number of donors is much larger than that of acceptors (such as PCFBT_0.1 ) in one repeat unit, the ICT character can disappear, and the localized exciton decay process is dominant in the relaxation of the copolymer, which also involves an excitation intensity‐independent vibrational thermal relaxation process at the initial time. The results further the understanding of the basic structure‐property relationship. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 992–996     

Structure and dynamics of polymeric materials in nano-scale

The nano-palpation technique,i.e.,nanometer-scale elastic and viscoelastic measurements based on atomic force microscope,is introduced.It is demonstrated to be very useful in analyzing nanometer-scale materials properties for the surfaces and interfaces of various types of soft materials.It enables us to obtain not only structural information but also mechanical information about a material at the same place and at the same time.     

A New Dimeric Alkaloid from the Leaf of Psychotria calocarpa

Psychotriasine was isolated from the leaves of Psychotria calocarpa (Rubiaceae). The structure was established by spectroscopic methods including 2D‐NMR analysis. To the best of our knowledge, psychotriasine is the first example of a dimeric tryptamine‐related alkaloid that contains a free N^α‐methyltryptamine unit in the molecule.     

Biologically Active Iridoids from Hedyotis diffusa

Two new iridoids, 10‐O‐benzoyl‐6′‐O‐α‐L ‐arabino(1→6)‐β‐D ‐glucopyranosylgeniposidic acid ( 1 ), deacetyl‐6‐ethoxyasperulosidic acid methyl ester ( 2 ), along with 14 other known iridoids, were isolated from the whole plant of Hedyotis diffusa Willd. Their structures were determined on the basis of spectroscopic analysis. The short‐term‐memory‐enhancement activities of compounds 1, 7 – 9, 11 , and 13 were evaluated on an Aβ transgenic drosophila model.