Aerosol particles at a high-altitude site on the Southeast Tibetan Plateau, China: Implications for pollution transport from South Asia

      Bulk aerosol samples were collected from 16 July 2008 to 26 July 2009 at Lulang, a high-altitude (>3300m above sea level) site on the southeast Tibetan Plateau (TP); objectives were to determine chemical characteristics of the aerosol and identify its major sources. We report aerosol (total suspended particulate, TSP) mass levels and the concentrations of selected elements, carbonaceous species, and water-soluble inorganic ions. Significant buildup of aerosol mass and chemical species (organic carbon, element carbon, nitrate, and sulfate) occurred during the premonsoon, while lower concentrations were observed during the monsoon. Seasonal variations in aerosol and chemical species were driven by precipitation scavenging and atmospheric circulation. Two kinds of high-aerosol episodes were observed: one was enriched with dust indicators (Fe and Ca2+), and the other was enhanced with organic and elemental carbon (OC and EC), SO42−, NO3−, and Fe. The TSP loadings during the latter were 3 to 6 times those on normal days. The greatest aerosol optical depths (National Centers for Environmental Protection/National Center for Atmospheric Research reanalysis) occurred upwind, in eastern India and Bangladesh, and trajectory analysis indicates that air pollutants were transported from the southwest. Northwesterly winds brought high levels of natural emissions (Fe, Ca2+) and low levels of pollutants (SO42−, NO3−, K+, and EC); this was consistent with high aerosol optical depths over the western deserts and Gobi. Our work provides evidence that both geological and pollution aerosols from surrounding regions impact the aerosol population of the TP

In-plane and Out-of-plane Plasma Resonances in Optimally Doped La1.84Sr0.16CuO4

We addressed the inconsistency between the electron mass anisotropy ratios determined by the far-infrared experiments and DC conductivity measurements. By eliminating possible sources of error and increasing the sensitivity and resolution in the far-infrared reflectivity measurement on the single crystalline and on the polycrystalline La1.84Sr0.16CuO4, we have unambiguously identified that the source of the mass anisotropy problem is in the estimation of the free electron density involved in the charge transport and superconductivity. In this study we found that only 2.8 % of the total doping-induced charge density is itinerant at optimal doping. Our result not only resolves the mass anisotropy puzzle but also points to a novel electronic structure formed by the rest of the electrons that sets the stage for the high temperature superconductivity

Shredding energy consumption of GFRP composite waste

This work investigated effect of glass fibre fabric structures, feedstock feed rate and screen size on specific shredding energy of glass fibre reinforced plastics (GFRP) waste via a two-level factorial design of experiment study. Four types of fabric structure, i.e. unidirectional (UD), biaxial (BIAX), triaxial (TRIAX) and chopped strand mat (CSM), were impregnated separately with unsaturated polyester resin to manufacture GFRP plates. The shredding energy was measured using a two-wattmeter approach. During shredding, CSM demonstrated a relatively flat power consumption curve compared to other fabric types. It was also noticed that the GFRP plate reinforced with more complex woven structure, i.e. TRIAX, required higher energy for shredding, especially with a combination of high feed rate and small screen size. It was found that mechanical efficiency was only around 8.2-15.7% and 0.8-2.2% for shredding at feed rate of 60 kg/hr and 10 kg/hr respectively. It was also found that adopting a larger screen size and lower feed rate could reduce the specific shredding energy

The σ\sigma pole in J/ψ→ωπ+π−J/\psi \to \omega \pi^+ \pi^-

Using a sample of 58 million $J/\psi$ events recorded in the BESII detector, the decay $J/\psi \to \omega \pi^+ \pi^-$ is studied. There are conspicuous $\omega f_2(1270)$ and $b_1(1235)\pi$ signals. At low $\pi \pi$ mass, a large broad peak due to the $\sigma$ is observed, and its pole position is determined to be $(541 \pm 39)$ - $i$ $(252 \pm 42)$ MeV from the mean of six analyses. The errors are dominated by the systematic errors.Comment: 15 pages, 6 figures, submitted to PL

The molecular systems composed of the charmed mesons in the HSˉ+h.c.H\bar{S}+h.c. doublet

We study the possible heavy molecular states composed of a pair of charm mesons in the H and S doublets. Since the P-wave charm-strange mesons $D_{s0}(2317)$ and $D_{s1}(2460)$ are extremely narrow, the future experimental observation of the possible heavy molecular states composed of $D_s/D_s^\ast$ and $D_{s0}(2317)/D_{s1}(2460)$ may be feasible if they really exist. Especially the possible $J^{PC}=1^{--}$ states may be searched for via the initial state radiation technique.Comment: 42 pages, 4 tables, 31 figures. Improved numerical results and Corrected typos

An Investigation into Contribution I-Intention and We-Intention in Open Web-Based Encyclopedia: Roles of Joint Commitment and Mutual Agreement

In the current study, knowledge contribution in open web-based encyclopedia is conceptualized as a group-referent intentional social action, and we-intention, which reflects one’s perception of the group acting as a unit, has been employed. The motivation of this study thus is to better understand antecedents and consequences of contribution I-intention and we-intention in open web-based encyclopedia. A research model was developed and empirically examined with 202 knowledge contributors in two most famous wiki communities in Mainland China. The results demonstrated that personal outcome expectations exert significant effects on both intentions. Joint commitment, mutual agreement and community-related outcome expectations are significantly related to we-intention to contribute, but not related to I-intention. In addition, we-intention has a statistically significant positive effect on contribution behavior. However, I-intention negatively relates to contribution behavior. We believe this study will serve as a starting point for furthering our limited understanding of the intentional social action in knowledge management research

We-Intention to Use Instant Messaging for Collaboration: A Social Influence Model

The purpose of this study is to introduce the concept of “we-intention” into group technology adoption and diffusion research. In this study, we examined the “we-intention” of using instant messaging for team collaboration. Building upon the social influence framework, a we-intention model is developed and tested with 163 respondents. The research model explained 41.3% of the variance in we-intention. Attitude, group norm and social identity were found to be statistically significant in determining we-intention to use instant messaging for collaboration, and value perception had significant effects on attitude and social influence factors. We believe that the implications of this study are important for both researchers and practitioners

Measurements of Cabibbo Suppressed Hadronic Decay Fractions of Charmed D0 and D+ Mesons

Using data collected with the BESII detector at $e^{+}e^{-}$ storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo suppressed hadronic weak decays $D^0 \to K^- K^+$, $\pi^+ \pi^-$, $K^- K^+ \pi^+ \pi^-$ and $\pi^+ \pi^+ \pi^- \pi^-$, $D^+ \to \bar{K^0} K^+$, $K^- K^+ \pi^+$ and $\pi^- \pi^+ \pi^+$ are presented.Comment: 11 pages, 5 figure