Synthesis and supercapacitor characteristics of PANI/CNTs composites

The polyaniline coated multi-walled carbon nanotubes (PANI/CNTs) composites were synthesized by in situ polymerization. The microstructure and component of the composites were characterized by scanning electron microscope (SEM), Fourier transfer infrared spectroscopy (FTIR), X-ray diffraction (XRD), and N2 adsorption BET. The electrochemical performances of the samples were tested by cyclic voltammogram (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge. The results showed...     

Crust-mantle coupling in North China: Preliminary analysis from seismic anisotropy

Data from the CASN (Capital Area Seismograph Network), NSNC (National Seismograph Network of China), and IRIS (Incor-porated Research Institutions for Seismology) are compared with data from a temporary North China Seismic Array to obtain the background orientation of the horizontal crustal principal compressive stress at NE 95.1°±15.4° in North China. Data are corrected for disturbances of faults and irregular tectonics, and are used to constrain the fast SKS polarization at NE 110.2°±15.8° in North China. Individual station analyses suggests that there is consistently more than 10° difference between the polarizations of fast shear-wave in the crust and those of fast SKS phases. Azimuthally anisotropic phase velocities of Rayleigh waves at different periods also indicate an orientation change for fast velocity with depth. It suggests the crust-mantle coupling in North China follows neither the simple decoupling model nor the strong coupling model. Instead, it is possibly some inhomogeneous combination of two models or some gradual-change model of physical characteristics. This study shows that anisotropy in the crust and mantle could be multiply characterized more correctly and crust-mantle coupling could be analyzed further, if increasing near-field shear-wave splitting data that indicate crustal anisotropy, combined with the azimuthal anisotropy of Rayleigh waves, besides the result of SKS splitting travelling through lithosphere and surface GPS measurements.     

First observation of mesospheric and thermospheric winds by a Fabry-Perot interferometer in China

A Fabry-Perot interferometer, funded by the Meridian Project in China, was deployed at the Xinglong station (40.2°N,117.4°E) of the National Astronomical Observatories in Hebei Province, China. The instrument has been operating since April 2010, measuring mesospheric and thermospheric winds. The first observational data of winds at three heights in the mesosphere and thermosphere were analyzed, demonstrating the capacity of this instrument to aid basic scientific research. The wavelengths of three airglow emissions were OH892.0, OI 557.7, and OI 630.0 nm, which corresponded to heights of 87, 98, and 250 km, respectively. Three 38-day data sets of horizontal winds, from April 5, 2010 to May 12, 2010, show clear day-to-day variations at the same height. The minimum and maximum meridional winds at heights of 87, 98, and 250 km were –16.5 to 8.7 m/s, –24.4 to 15.9 m/s, and –43.6 to 1.5 m/s. Measurements of zonal winds were –5.4 to 7.6 m/s, 2.3 to 23.0 m/s, and –22.6 to 49.3 m/s. The average data from the observations was consistent with the data from HWM93. The wind data at heights of 87 and 98 km suggest a semi-diurnal oscillation, clearly consistent with HWM93 results. Conversely there was a clear discrepancy between the observations and the model at 250 km. In general, this Fabry-Perot interferometer is a useful ground-based instrument for measuring mesospheric and thermospheric winds at middle latitudes.     

Fabrication and characterization of 3D scaffold using 3D plotting system

In this paper, we design and fabricate a 3D scaffold using rapid prototyping (RP) technology for tissue engineering. The scaffold should have a three-dimensional interconnected pore network. We fabricate a polycaprolactone (PCL) scaffold with interconnecting pores and uniform porosity for cell ingrowth using a 3D plotting system. In order to keep the three dimensional shape under mechanical loading while implanted, we design an oscillating nozzle system to increase elastic modulus and yield strength of PCL ...     

Occurrence of Neoproterozoic low-grade metagranite in the western Beihuaiyang zone,the Dabie orogen

Based on detailed field investigations and petrographic observations, we discovered Neoproterozoic-emplaced granite from the metavolcanics of the Dingyuan Formation in the western Beihuaiyang zone, the Dabie orogen. This study reports the results of zircon U-Pb dating and preliminary petrographic observations on two metagranite samples. The studied rocks experienced epidote-amphibolite facies metamorphism and strong structural deformation. Their U-Pb ages are 726 ± 6 and 758 ± 12 Ma, respectively, similar to those for the Luzhenguan complex in the eastern segment of the Beihuaiyang zone. In combination with previously determined 635 ± 5 Ma low-grade metagabbro, this study suggests the occurrence of at least two types of Neoproterozoic intrusive rocks in the Beihuaiyang zone, the northern margin of the South China Block (SCB): 726–758 Ma metagranite and 635 Ma metagabbro. These rocks occur within the metamorphosed Ordovician volcanic zone (originally named the Dingyuan Formation) and are in tectonic contact to each other, but they formed in different tectonic settings. The protolith ages for the Neoproterozoic low-grade metaigneous rocks are in good agreement not only with ages for two episodes of mid- and late-Neoproterozoic mafic and felsic magmatism in the Suizhou and Zaoyang area, Hubei Province, but also agree with protolith ages of ultrahigh-pressure metaigneous rocks in the Dabie-Sulu orogenic belt. In view of their tectonic relationships to country rocks, it appears that these Neoproterozoic low-grade rocks are exotic and they may have been detached and scraped from subducting SCB crust in the early Triassic during the initial continental subduction, and thrusted over Paleozoic metamorphosed rocks in the southern margin of the North China Block during continental collision.     

Restricted allowable generalized quantum gates

An allowable generalized quantum gate (introduced by Long, Liu and Wang) has the form of U = Σ _k=0 ^d−1 c _k U _k , where U _k’s are unitary operators on a Hilbert space H and |Σ _k=0 ^d−1 c _k |⩽1 and |c _k |⩽1 (0⩽k⩽d−1). In this work we consider a kind of AGQGs, called restricted allowable generalized quantum gates (RAGQGs), satisfying 0 < Σ _k=0 ^d−1|c _k |⩽1. Some properties of the set RAGQG(H) of all RAGQGs on H are established. Especially, we prove that the extreme points of RAGQG(H) are exactly unitary operators on H and that B(H)=R ⁺ RAGQG(H).     

Study on the micro-region structure and properties of two dithienothiophene-dicarboxylic acids

Self-organized dithieno [3,2-b:2',3'-d] thiophene-2,5-dicarboxylic acid (A) and dithieno [2,3-b:3',2'-d] thiophene-2,5-dicarboxylic acid (B) films were prepared through solvent-induced order-disorder transition method.The arrangement of the two molecules on substrates were observed by atomic force microscopy (AFM),which demonstrated that A was arranged orderly in a certain angle on mica,while B was flat-flying on mica.The optical and conductance properties in micro region of these two compound films were ch...     

Effect of wing planform on leading-edge vortex structures

Flow visualization experiments are conducted in water tunnel for low aspect ratio cropped wings at low Reynolds number. The experimental results show that the model sweep angle Λ influences the formation and development of the leading-edge vortex. For wings with Λ =0°, the dominant flow structure is transverse vortex. When Λ≥26°, the dual vortex structure can be observed at some angles of attack, and it is confirmed that the dual vortex is a special structure for flow over low aspect ratio wing at low Reyno...     

Effects of carbon diffusing field in alloy solvent on the growth of tower-shape diamond single crystal

High-quality type-Ib tower-shape diamond single crystals were synthesized in cubic anvil high pressure apparatus (SPD-6×1200) at 5.4 GPa and 1250-1450°C. The (100) face of seed crystal was used as the growth face, and FeNiMnCo alloy was used as the solvent/catalyst. Two kinds of carbon diffusing fields (type-B and type-G) were simulated by finite element method (FEM). Using the two kinds of carbon diffusing fields, many diamond single crystals were synthesized. The effects of carbon diffusing fields on the ...