Two-dimensional heterogeneous photonic bandedge laser

We proposed and realized a two-dimensional (2D) photonic bandedge laser surrounded by the photonic bandgap. The heterogeneous photonic crystal structure consists of two triangular lattices of the same lattice constant with different air hole radii. The photonic crystal laser was realized by room-temperature optical pumping of air-bridge slabs of InGaAsP quantum wells emitting at 1.55 micrometer. The lasing mode was identified from its spectral positions and polarization directions. A low threshold incident pump power of 0.24mW was achieved. The measured characteristics of the photonic crystal lasers closely agree with the results of real space and Fourier space calculations based on the finite-difference time-domain method.Comment: 14 pages, 4 figure

Investigating Information Systems Infusion and the Moderating Role of Habit: A User Empowerment Perspective

Organizations have made significant investments in information systems (IS) implementation. However, more than half of these IS implementations have reported failures due to underutilization. Although it is known that IS infusion is required for realizing expected returns on investments, most IS research has focused on initial adoption and continuance with only a handful examined infusion. These few IS infusion studies have produced inconclusive results as they have employed models and factors that are used for adoption and continued use. Compare to adoption and continuance, IS infusion requires authentic motivation of users. Thus, this study examines IS infusion using user empowerment as the authentic motivation based on the psychological empowerment theory which can explain employee’s behavior beyond management prescription. Results show that the four user empowerment dimensions have significant effects on the three IS infusion subtypes. Further, results show that habit attenuates the importance of user competence for extended use and integrative use but reinforces the importance of usage meaning for extended use and user self-determination for integrative use. This study advances our theoretical understanding of IS infusion and offers suggestions to organizations in achieving IS infusion

Effect of admixtures on the yield stresses of cement pastes under high hydrostatic pressures

When cement-based materials are transported at a construction site, they undergo high pressures during the pumping process. The rheological properties of the materials under such high pressures are unknown, and estimating the workability of the materials after pumping is a complex problem. Among various influential factors on the rheology of concrete, this study investigated the effect of mineral and chemical admixtures on the high-pressure rheology. A rheometer was fabricated that could measure the rheological properties while maintaining a high pressure to simulate the pumping process. The effects of superplasticizer, silica fume, nanoclay, fly ash, or ground granulated blast furnace slag were investigated when mixed with two control cement pastes. The water-to-cement ratios were 0.35 and 0.50.ope

ON POSITIVE QUATERNIONIC KÄHLER MANIFOLDS WITH b_4=1

Let M be a positive quaternionic Kähler manifold of dimension 4m. In earlier papers, Fang and the first author showed that if the symmetry rank is greater than or equal to [m=2]+3, then M is isometric to HP^m or Gr_2(C^). The goal of this paper is to give a more refined classification result for positive quaternionic Kähler manifolds (in particular, of relatively low dimension or with even m) whose fourth Betti number equals one. To be precise, we show in this paper that if the symmetry rank of M with b_4(M)=1is no less than [m/2]+2 for ≥5, then M is isometric to HP^m

Robust Co-catalytic Performance of Nanodiamonds Loaded on WO3 for the Decomposition of Volatile Organic Compounds under Visible Light

Proper co-catalysts (usually noble metals), combined with semiconductor materials, are commonly needed to maximize the efficiency of photocatalysis. Search for cost-effective and practical alternatives for noble-metal co-catalysts is under intense investigation. In this work, nanodiamond (ND), which is a carbon nanomaterial with a unique sp(3)(core)/sp(2)(shell) structure, was combined with WO3 (as an alternative co-catalyst for Pt) and applied for the degradation of volatile organic compounds under visible light. NDs-loaded WO3 showed a highly enhanced photocatalytic activity for the degradation of acetaldehyde (similar to 17 times higher than bare WO3), which is more efficient than other well-known co-catalysts (Ag, Pd, Au, and CuO) loaded onto WO3 and comparable to Pt-loaded WO3. Various surface modifications of ND and photoelectochemical measurements revealed that the graphitic carbon shell (sp(2)) on the diamond core (spa) plays a crucial role in charge separation and the subsequent interfacial charge transfer. As a result, ND/WO3 showed much higher production of OH radicals than bare WO3 under visible light. Since ND has a highly transparent characteristic, the light shielding that is often problematic with other carbon-based co-catalysts was considerably lower with NDs-loaded WO3. As a result, the photocatalytic activity of NDs/WO3 was higher than that of WO3 loaded with other carbon-based co-catalysts (graphene oxide or reduced graphene oxide). A range of spectroscopic and photo(electro)chemical techniques were systematically employed to investigate the properties of NDs-loaded WO3. ND is proposed as a cost-effective and practical nanomaterial to replace expensive noble-metal co-catalysts.1124Ysciescopu

Designing Urban Media Storytelling through Greimas ’ Narrative Model

This article attempts to establish an urban media storytelling model based on Greimas’ narrative model. Greimas ’ narrative model is distinguished into Narrative Schema model and Actantial model. Of course, other contents that reproduced through urban media can also establish storytelling strategies using these. Moreover, it can also be utilized in establishing a storytelling that applies to the entire space called “city. ” To be more specific, it is a process that receives information and entertainment based on the city, explores the city and ultimately recognizes the city image. This writing suggest such storytelling design linked with a narrative schema and actantial model