Traffic density, congestion externalities, and urbanization in China

<p>Although there is an abundant regional literature analyzing traffic congestion, only a few studies have explored extending such analysis with spatial effects. This study uses a dynamic spatial Durbin model and city-level panel data for the period 2003–14 to investigate the spatial spillover effects of traffic congestion on urbanization in China. The results show that there is an inverted ‘U’-shaped relationship between urbanization and traffic density in local and neighbouring cities, and congestion effects have appeared. In the short and long run, the spatial effects of traffic congestion have become an important force restricting the effective promotion of urbanization in China.</p

Amphiphilic polymer and processes of forming the same

Disclosed are an amphiphilic polymer, its synthesis and uses thereof. The polymer has a hydrocarbon backbone with —COOH side groups. It further has first aliphatic moieties with a main chain of about 3 to about 20 carbon atoms and 0 to about 3 heteroatoms, and second aliphatic moieties that have a main chain of about 3 to about 80 carbon atoms and about 2 to about 40 heteroatoms. The second aliphatic moieties have a copolymerisable group. In the synthesis a maleic anhydride polymer of formula (I) where n is an integer from about 10 to about 10000 and R1 is H or methyl, is reacted with a monofunctional compound with an alkyl chain of about 3 to about 20 carbon atoms and 0 to about 2 heteroatoms, and with an at least bifunctional compound with an alkyl chain of about 3 to about 80 carbon atoms and 0 to about 40 heteroatoms. The functional group of the monofunctional compound and one functional group of the at least bifunctional compound can form a linkage with an anhydride. Another functional group of the at least bifunctional compound, which is not allowed to react with the maleic anhydride polymer, is copolymerisable

Self-supporting lithiophilic N-doped carbon rod array for dendrite-free lithium metal anode

Carbon materials as host matrix of lithium (Li) anode attract more and more attention in order to inhibit uncontrollable dendritic growth of Li. Powdery carbon materials are usually synthesized and loaded on current collector by binder. The pore structure and active site of powdery materials will be easily destroyed during cycling. Herein, a self-supporting carbon film consisting of nitrogen (N)-doped carbon rod array (NCRA) with high N content and large surface area skeleton is developed as Li host matrix to regulate Li metal nucleation and suppress dendrites growth. The NCRA matrix exhibits low lithium loss mass and good long-term cycling stability during Li plating/stripping. The loss mass of Li in each cycle on NCRA is less than 0.01 mg cm(-2) at 1.0 mA cm(-2) and the value is much smaller than that (0.063 mg cm(-2)) on Cu foil. The Li vertical bar NCRA@Li symmetric cell has ultralong lifespan beyond 620 h and small voltage hysteresis of less than 40 mV at 2.0 mA cm(-2). The good electrochemical performance is ascribed to the stable self-supporting array structure for the storage of Li and abundant lithiophilic active sites for uniform Li electrodeposition in NCRA host matrix. Therefore, the dendritic growth of Li is effectively inhibited. This study provides a promising self-supporting lithiophilic NCRA as host material of Li anode to promote practical application in next-generation lithium-metal based batteries

Online Detection of Peroxidase Using 3D Printing, Active Magnetic Mixing, and Spectra Analysis

A new method for online detection of peroxidase (POD) using 3D printing, active magnetic mixing, fluidic control, and optical detection was developed and demonstrated in this study. The proposed POD detection system consisted of a 3D printing and active magnetic mixing based fluidic chip for online catalytic reaction, an optical detector with a fluidic flow cell for quantitative determination of the final catalysate, and a single-chip microcontroller based controller for automatic control of two rotating magnetic fields and four precise peristaltic pumps. Horseradish peroxidase (HRP) was used as research model and a linear relationship between the absorbance at the characteristic wavelength of 450 nm and the concentration of HRP of 1/4–1/128 μg mL−1 was obtained as A  =  0.257ln⁡(C) + 1.425 (R2  = 0.976). For the HRP spiked pork tests, the recoveries of HRP ranged from 93.5% to 110.4%, indicating that this proposed system was capable of detecting HRP in real samples. It has the potential to be extended for online detection of the activity of other enzymes and integration with ELISA method for biological and chemical analysis

Single light emitters in electrospun polymer nanofibers: Effect of local confinement on radiative decay

The fabrication of light emitting polymer nanofibers by electrospinning of polymer solutions containing either fluorescent organic dye molecules or luminescent semiconductor nanoparticles (quantum dots) is presented. The fluorescence spectra and lifetime of the embedded emitters, down to the level of single molecules were investigated. While the average fluorescence lifetime of single molecules embedded in poly(methyl methacrylate) fibers appears independent of the fiber diameter, the single molecule approach reveals a significant broadening of the fluorescence lifetime distribution for fibers with diameters below the wavelength of light.\ud \u

Memory in quantum-dot photoluminescence blinking

10.1088/1367-2630/7/1/197New Journal of Physics7

Target Lines for in Planta Gene Stacking in Japonica Rice

The clustering of transgenes at a chromosome location minimizes the number of segregating loci that needs to be introgressed to field cultivars. Transgenes could be efficiently stacked through site-specific recombination and a recombinase-mediated in planta gene stacking process was described previously in tobacco based on the Mycobacteriophage Bxb1 site-specific integration system. Since this process requires a recombination site in the genome, this work describes the generation of target sites in the Japonica rice genome. Agrobacterium-mediated gene transfer yielded ~4000 random-insertion lines. Seven lines met the criteria of being single copy, not close to a centromere, not inserted within or close to a known gene or repetitive DNA, having precise recombination site sequences on both ends, and able to express the reporter gene. Each target line tested was able to accept the site-specific integration of a new gfp-containing plasmid and in three of those lines, we regenerated fertile plants. These target lines could be used as foundation lines for stacking new traits into Japonica rice