436 research outputs found

    Redox-Active Molecules for Novel Nonvolatile Memory Applications

    Get PDF
    The continuous complementary metal‐oxide‐semiconductor (CMOS) scaling is reaching fundamental limits imposed by the heat dissipation and short‐channel effects, which will finally stop the increase of integration density and the MOSFET performance predicted by Moore’s law. Molecular technology has been aggressively pursued for decades due to its potential impact on future micro‐/nanoelectronics. Molecules, especially redox‐active molecules, have become attractive due to their intrinsic redox behavior, which provides an excellent basis for low‐power, high‐density, and high‐reliability nonvolatile memory applications. This chapter briefly reviews the development of molecular electronics in the application of nonvolatile memory. From the mechanical motion of molecules in the Langmuir‐Blodgett film to new families of redox‐active molecules, memory devices involving hybrid molecular technology have shown advantageous potential in fast speed, low‐power, and high‐density nonvolatile memory and will lead to promising on‐chip memory as well as future portable electronics applications

    Protecting the Giant Pandas: Newspaper Censorship of Negative News

    Get PDF
    We investigate newspaper censorship of firm-level negative news using a rare setting in which many companies were involved in similar tunneling scandals. We find that the Chinese censorship authorities restrict the dissemination of tunneling news on state-owned enterprises, firms with greater numbers of employees, and large taxpayers. An examination of the difference in censorship behaviors between the central and provincial authorities reveal three incentives that direct the censorship practices: strong local protectionism, cross-provincial competition, and the concern for the relative positions in the political power system. Finally, we show that the tunneling news that is reported leads to negative market reactions and greater trading volumes, indicating that the news that survives the censorship has information content

    Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough receiver

    Get PDF
    This paper proposes a comprehensive thermodynamic and economic model to predict and compare the performance of concentrated solar power plants with traditional and novel receivers with different configurations involving operating temperatures and locations. The simulation results reveal that power plants with novel receivers exhibit a superior thermodynamic and economic performance compared with traditional receivers. The annual electricity productions of power plants with novel receivers in Phoenix, Sevilla, and Tuotuohe are 8.5%, 10.5%, and 14.4% higher than those with traditional receivers at the outlet temperature of 550°C. The levelized cost of electricity of power plants with double-selective-coated receivers can be decreased by 6.9%, 8.5%, and 11.6%. In Phoenix, the optimal operating temperature of the power plants is improved from 500°C to 560°C by employing a novel receiver. Furthermore, the sensitivity analysis of the receiver heat loss, solar absorption, and freeze protection temperature is also conducted to analyze the general rule of influence of the receiver performance on power plants performance. Solar absorption has a positive contribution to annual electricity productions, whereas heat loss and freeze protection temperature have a negative effect on electricity outputs. The results indicate that the novel receiver coupled with low melting temperature molten salt is the best configuration for improving the overall performance of the power plants

    Free gas accumulations in basal shear zones of mass-transport deposits (Pearl River Mouth Basin, South China Sea): An important geohazard on continental slope basins

    Get PDF
    Free gas is an important trigger of instability on continental slopes, and resulting mass-wasting strata can potentially form competent seals to hydrocarbon accumulations. This work uses two high-quality 3D seismic volumes to investigate fluid accumulations at the base of mass-transport deposits in the Pearl River Mouth Basin, South China Sea. In parallel, IODP/ODP borehole data are used to document the petrophysical character of mass-transport deposits formed in similar continental-slope environments to the South China Sea. The interpreted data show gas accumulations as comprising enhanced seismic reflections that are discordant, or vertically stacked, below mass-transport deposits with chaotic seismic facies. Gas was accumulated in basal shear zones of mass-transport deposits in response to differences in capillary pressure and porosity. Free gas in Zone A covers an area of at least 18 km2. In Zone B, the free gas is sub-circular in plan view and covers an area of 30.58 km2 for a volume of sediment approaching 1.5 km3. This work is important as it shows that vertical migration of gas is not significant in mass-transport deposits from the Pearl River Mouth Basin, but up-dip migration along their basal shear zones is suggested in multiple locations. As a result, free gas can pinch-out laterally to extend 1–2 km beyond these same basal shear zones. As a corollary, we show that free gas accumulations below mass-transport deposits comprise an important geohazard and should be taken into account when drilling continental-slope successions in both the South China Sea and continental margins recording important mass wasting. Strata charged with free gas form weak layers, hinting at a novel trigger of retrogressive slope failures on continental slopes worldwide

    3D-printed polycaprolactone-chitosan based drug delivery implants for personalized administration

    Get PDF
    Fused deposition molding (FDM) can complete most complex preparation of drug delivery implants to meet the personalized needs of patients. However, the drug activity has strict requirements on processing temperature and preparation method of filaments, the implant also has strict biocompatibility requirements for the materials. In this study, a drug delivery implant was prepared with good biocompatibility, controlled and efficient drug release using FDM printing for personalized administration. Drug-loaded filaments were developed for FDM process by hot-melt extrusion (HME). Polycaprolactone was used as a drug delivery carrier, and ibuprofen as the model drug. Notably, chitosan was dissolved to form controlled and efficient release channels. The printability, changes in physical and chemical properties during HME and FDM processes of the filament, and drug release behavior, mechanism and biocompatibility of the implants were investigated. The results showed that the filament tensile strength decreased with the increase of drug and chitosan content. No obvious degradation and chemical change occurred during the whole process. The drug release efficiency could reach\u3e99% and lasted for 120 h mainly via the diffusion - erosion mechanism. The viability of cells cultured for 24 h in 72 h, 100% implant extract was 75.3%
    corecore