Showing papers by "Rong Wang published in 2009"

Development and application of EST-STS markers specific to chromosome 1RS of Secale cereale

Abstract: Molecular markers are important tools that have been used to identify the short arm of rye chromosome 1R (1RS) which contains many useful genes introgressed into wheat background. Wheat expressed sequence tag (EST) sequences are valuable for developing molecular markers since ESTs are derived from gene transcripts and more likely to be conserved between wheat and its relative species. In the present study, 35 sequence-tagged site (STS) primers were designed based on EST sequences distributed on homology group 1 chromosomes of Triticum aestivum and used to screen specific markers for chromosome 1RS of Secale cereale . Two primer pairs different from the early studies, STS WE3 , which amplified a 1680-bp and a 1750-bp fragment, and STS WE126 , which produced a 850-bp fragment from rye genome, were proved to be specific to chromosome 1RS since the corresponding fragments were only amplified from 1R chromosome addition line and wheat-rye lines with chromosome 1RS, but not from wheat-rye 2R-7R chromosome addit...

Responsive polymer nanoparticles formed by poly(ether amine) containing coumarin units and a poly(ethylene oxide) short chain.

Abstract: We reported a novel poly(ether amine) (PEAC) containing poly(ethylene oxide) (PEO) short blocks and coumarin units, which was synthesized by nucleophilic addition/ring-opening polymerization of diepoxy and diamine monomers. PEAC can be directly dispersed in aqueous solution as uniformly sized nanoparticles 50−60 nm in diameter. The whole process for aggregation of PEAC was revealed by transmission electron microscopy (TEM) and ultraviolet−visible (UV−vis) spectra. The results show that these polymeric nanoparticles possess a very sharp response to temperature and light, and can form complex micromicelles with nanoparticles inside.

Two-state competition in 1.3 μm multilayer InAs/InGaAs quantum dot lasers

Abstract: The competition of ground state (GS) and excited state (ES) is investigated from the as-grown and thermally annealed 1.3 μm ten-layer p-doped InAs/GaAs quantum dot (QD) lasers. The modal gain competition between GS and ES are measured and analyzed around the ES threshold characteristics. Our results show that two-state competition is more significant in devices with short cavity length operating at high temperature. By comparing the as-grown and annealed devices, we demonstrate enhanced GS and suppressed ES lasing from the QD laser annealed at 600 °C for 15 s.

Temperature Characteristics of Gain Profiles in 1.3- $ \mu\hbox{m}\ p$ -Doped and Undoped InAs/GaAs Quantum-Dot Lasers

Abstract: The modal gain and differential gain of 1.3-mum p-doped and undoped InAs/GaAs quantum-dot (QD) lasers have been investigated as a function of injection current under different operation temperatures. The results show that p-doping improves the modal and differential gains in QD lasers at high temperatures. Exponential decrease in the differential gain profiles were observed in both types of lasers from 20degC to 80degC. Theoretical calculations based on the rate equation model for the undoped QD laser gain at different temperatures are presented.

Method for the production of an asymmetric hollow fiber membrane

Abstract: The present invention provides a method for the production of a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) asymmetric hollow fiber membrane. The invention comprises preparing a dope solution of PVDF-HFP with an additive of lithium chloride or glycerol dissolved in a solvent such as N-methylpyrollidone (NMP). The dope solution is spun to form a PVDF-HFP asymmetric hollow fiber membrane.

INCLUSION COMPLEX FORMATION BETWEEN α-CYCLODEXTRIN AND BIODEGRADABLE COMBLIKE COPOLYMERS WITH POLY(α,β-MALIC ACID) BACKBONES AND MPEG SIDE CHAINS

Abstract: Inclusion complexes (ICs) composed of α-cyclodextrins (α-CD) and biodegradable comblike copolymers with poly(α,β-malic acid) (PMA) backbones and methylated poly(ethylene glycol) (mPEG) side chains were prepared by the host-guest reaction. Two series of ICs with mPEG750 and mPEG2000 were prepared. The stoichiometry (EG/CD) of all the ICs in mPEG2000 series was 3.1, no matter what the graft degree was. While in mPEG750 series, the stoichiometry (EG/CD) was very different; it increased with the amount of mPEG decreasing. The decomposition temperatures of the fragments in ICs were closely related to graft degrees. The stack of α-CDs in ICs was a channel-type structure. The crystal of ICs was lamellar, and it could be reorganized to well-defined supermolecular structure.