From December 2011 to May 2014, about 5 fb−1 of data were taken with the BESIII detector at center-of-mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher ...excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.
Using data samples collected with the BESIII detector at the BEPCII collider at six center-of-mass energies between 4.008 and 4.600 GeV, we observe the processes e(+)e(-) -> phi phi omega and ...e(-)e(-) -> phi phi phi. The Born cross sections are measured and the ratio of the cross sections sigma(e(+)e(-) -> phi phi omega)/sigma(e(-)e(-) -> phi phi phi) is estimated to be 1.75 +/- 0.22 +/- 0.19 averaged over six energy points, where the first uncertainty is statistical and the second is systematic. The results represent first measurements of these interactions.
Nanocrystalline diamond films, prepared by a microwave plasma-enhanced CVD, were implanted using 110-keV nitrogen ions under fluence ranging from 10
16–10
17 ions cm
−2. AFM, XRD, XPS and Raman ...spectroscopy were used to analyze the changes in surface structure and chemical state of the films before and after implantation. Results show that high-fluence nitrogen ions implanted in the nanocrystalline diamond film cause a decline in diamond crystallinity and a swelling of the crystal lattice; the cubic-shaped diamond grains in the film transform into similar roundish-shaped grains due to the sputtering effect of implanted nitrogen ions. Nitrogen-ion implantation changes the surface chemical state of the nanocrystalline diamond film. After high-fluence implantation, the surface of the film is completely covered by a layer of oxygen-containing groups. This phenomenon plays an importance role in the reduction of the adhesive friction between an Al
2O
3 ball and the nanocrystalline diamond film.
•The NBKT15 thin films with typical perovskite polycrystalline phase were grown on LNO and Pt electrodes.•The NBKT15 thin film on LNO electrode exhibits better crystallinity, stronger remnant ...polarization and smaller leakage current.•The domain configurations of single grain are easier to be reversed by electric field for the NBKT15 thin film on LNO electrode.•The domain switching criterion was adopted to explain the mechanisms of electric-generated domain switchings.
Several researches have shown the bottom electrode can strongly affect the physical properties of thin film. However, they seldom involve with the domain switching performance. Here we investigated emphatically the effects of bottom electrodes LNO and Pt on the domain configurations of (Na0.85K0.15)0.5Bi0.5TiO3 (NBKT15) thin films using piezoresponse force microscopy. In comparison with the NBKT15 thin film on Pt electrode, the NBKT15 thin film on LNO electrode shows better performance in crystalline and electrical properties. Moreover the domain configuration of single grain within the NBKT15 thin film on LNO electrode is easier to be reversed under the electric fields, due to the larger grain size. Furthermore, we adopted the domain switching criterion from the perspective of equilibrium state free energy of ferroelectric nanodomain to explain the mechanisms of electric-generated domain switchings.
Bamboo curtains, coarse glass fiber cloth, bamboo mat, poplar veneer, and fine glass fiber cloth impregnated with phenolic resin adhesive were sequentially laid from the inside to the outside, and ...the symmetrically balanced material was sent to the hot press. The bonding mechanism of the resulting glass fiber-reinforced bamboo plywood (GFRBP) was analyzed using environmental scanning electron microscopy (ESEM) and Fourier transform infrared (FTIR) spectroscopy. The bonding between the phenolic resin and fiberglass cloth was achieved with a coupling agent, which reacted chemically with both the fiberglass cloth and phenolic resin. ESEM showed that glass fiber was bonded strongly with phenolic resin after treatment with coupling agents such as KH-550, KH-560, and KH-792. When the GFRBP was damaged, there was no breakage at the bonding surface between the glass fiber and phenolic resin. During the hot-pressing process, the phenolic resin easily migrated to the middle of the gap between plywood plates, which promoted better integration and properties. FTIR results showed that the longitudinal sides of the GFRBP pressed by the fiberglass cloth that had been treated by the coupling agents KH-550 and KH-792 were similar to each other, but those treated with KH-792 contained more -CH2- and had a longer carbon backbone.
A variety of studies has linked vasoactive intestinal peptide (VIP) to idiopathic pulmonary arterial hypertension (IPAH). In this study, we investigated the correlation between VIP gene variants and ...IPAH in Chinese population. A total of 81 consecutive unrelated patients diagnosed as IPAH from 2006 to 2008 and 250 controls were included in the study. VIP gene variants were screened by direct sequencing, and VIP serum level was determined by enzyme‐linked immunosorbent assay. Clinical and hemodynamic data of all patients were also obtained. The variant g.8129T→C in exon 7 was found to be the only variant in the coding region of VIP gene with a significantly higher frequency in patients (40.7%) than in control samples (15.2%). Moreover, there was marked difference in VIP serum level and hemodynamic data between IPAH patients with and without the variant. The variant g.8129T→C in exon 7 of VIP gene was correlated with the clinical phenotype of lower VIP serum level, higher mean pulmonary artery pressure and pulmonary vascular resistance in patients with IPAH comparing to those in patients without this variant. The VIP gene variant g.8129T→C may be one of the risk factors in the pathogenesis of IPAH.
Stable icosahedral quasicrystals with wide composition ranges have been found in the systems Cd-Mg-Yb and Cd-Mg-Ca. The icosahedral quasicrystals form in the following composition ranges: ...25-85at.%Cd, 0-60at.%Mg and 10-20at.%Yb for the Cd-Mg-Yb system; 33-85at.%Cd, 0-52at.%Mg and 10-20at.%Ca for the Cd-Mg-Ca system. An electron diffraction study confirmed that the icosahedral quasicrystals have a primitive lattice. Its quasilattice constant is proportional to a Goldschmidt atom diameter of the quasicrystals weighted by a factor of 1.75 in the range 0.5681- 0.5799nm for the Cd-Mg-Yb system and 0.5697-0.5778nm for the Cd-Mg-Ca system. The closely similar atom sizes of Cd and Mg, the valence electron ratio e / a =2.0 and the large atom sizes of Yb and Ca cause the wide composition ranges of the Cd-Mg-Yb and Cd-Mg-Ca quasicrystals. The metallurgical behaviour of the quasicrystals is discussed.
Understanding the spatiotemporal characteristics of ambient air quality and identifying the associated factors are helpful to develop integrated interventions to prevent and control air pollution. ...Based on daily data of air quality index (AQI) in 31 Chinese provincial capital cities in 2014, this study aimed to investigate the spatiotemporal variations of ambient air pollution and the influencing factors. The spatial and temporal patterns of AQI were presented using GIS map and heat map, respectively. We constructed a hierarchical linear model to quantify the effects of meteorological and socioeconomic factors on AQI. In 2014, the air quality nonattainment (AQI >100) rate was 34.6% on average (1.9 to 74.4%). Air pollution levels were highest in winters and lowest in summers. We found substantial spatial variations of AQI, with the highest values in the middle-east area of the North China Plain. The city-level AQI was positively associated with vehicle population, industrial dust emission, and GDP per capital, which cumulatively explained 67.5% of spatial variations of AQI. The city-level AQI also increased with city’s annual atmospheric pressure but decreased with annual mean temperature. Daily AQI within a city decreased with daily temperature, sunshine duration, wind speed, precipitation, and relative humidity. The national analyses indicate that the ambient air quality in China exhibits significant geographical and seasonal variations which were mainly driven by socioeconomic and meteorological factors. The findings would help to understand the underlying reasons for spatial health disparities and would provide important information to guide targeted policy response to ambient air pollution.
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