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Matlab/Simulink, Chemkin, as well as the finite element method (FEM) have been used to investigate the performance of the novel development of a two-stroke free-piston engine for electrical power generation. It is called free-piston linear alternator (FPLA). The motion differences between the FPLA and the internal combustion engine (ICE) are also presented. The effects of various resistance loads and equivalence ratios are studied. The simulation results show that the FPLA has a buildup nature to change the top dead center (TDC) according to loads and other parameters. The high compression ratio can be achieved easily by decreasing the equivalence ratio, which is an effective way to increase the indicated thermal efficiency. Besides, the peak temperature is much lower than the traditional engine under the same condition, which could reduce the temperature-dependent emissions.

Metal oxide nanocrystals have been pursued for various applications in photovoltaics as a buffer layer. However, it remains a challenging task to adjust their energy levels to achieve a better match of the donor–acceptor system. Herein, we report the fabrication of graphene quantum dots (GQDs) with bright blue photoluminescence by a top-down strategy based on laser fragmentation with posthydrothermal treatment. The GQDs demonstrate appropriate energy level positions and are used as an intermediate buffer layer between TiO2 and P3HT to form a cascade energy level architecture. The introduction of the GQDs into a bulk heterojunction hybrid solar cell has led to an enhancement of the power conversion efficiency.

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S pontaneous intracerebral hemorrhage (ICH) results from rupture of blood vessels in the brain. It represents ≈10% to 20% of all strokes and is a devastating clinical condition with a 30-day mortality rate of 30% to 55%.1 Currently, there is no proven treatment available for improving ICH outcome. Evidence suggest that ICH is associated with activation of local immune cells and release of inflammatory mediators, which result in enhanced disruption of the blood-brain barrier (BBB), causing an increase in peri-hematomal edema formation and consequent neuronal injury. [2][3][4] Cerebral edema is present in most patients with ICH and is an independent predictor of neurological deterioration.1,2 Therefore, strategies aimed at limiting inflammatory response and BBB dysfunction could be potential therapeutic targets for ICH.von Willebrand factor (VWF) is a multimeric adhesive protein that is released from endothelial Weibel-Palade bodies during injury or inflammation. 5 The multimeric size of VWF is modulated by ADAMTS 13 (a disintegrin and metalloprotease with thrombospondin type I motif, member 13), which processed proteolytically VWF into smaller lessreactive forms. 6 Accumulating data indicate that ADAMTS 13 and VWF play an opposite role in thrombus formation and Background and Purpose-Inflammatory responses and blood-brain barrier (BBB) dysfunction play important roles in brain injury after intracerebral hemorrhage (ICH). The metalloprotease ADAMTS 13 (a disintegrin and metalloprotease with thrombospondin type I motif, member 13) was shown to limit inflammatory responses through its proteolytic effects on von Willebrand factor. In the present study, we addressed the role of ADAMTS 13 after experimental ICH. Methods-ICH was induced in mice by intracerebral infusion of autologous blood. The peri-hematomal inflammatory responses, levels of matrix metalloproteinase-9 and intercellular adhesion molecule-1, pericyte coverage on brain capillaries, and BBB permeability were quantified at 24 hours. Functional outcomes, cerebral edema, and hemorrhagic lesion volume were quantified at day 3. Results-Treatment with recombinant ADAMTS 13 (rADAMTS 13) reduced the levels of chemokines and cytokines, myeloperoxidase activity, and microglia activation and neutrophil recruitment after ICH. rADAMTS 13 also decreased interleukin-6 expression in brain endothelial cells stimulated by lipopolysaccharide, whereas recombinant von Willebrand factor reversed this effect. The anti-inflammatory effect of rADAMTS 13 was accompanied by reduced expression of intercellular adhesion molecule-1 and less activation of matrix metalloproteinase, enhanced pericyte coverage of brain microvessels, and attenuated BBB disruption. Furthermore, neutrophil depletion protected against BBB damage, and rADAMTS 13 treatment had no further beneficial effect. Finally, treatment of mice with rADAMTS 13 reduced cerebral edema and hemorrhagic lesion volume and improved neurological functions. Conclusions-Our findings reveal the importance of rADAMTS 13 in regulating...

Although organometal halide perovskites have garnered enormous interest in solar cells, scarce attention has been paid to light-emitting devices using formamidinium lead halide perovskite as the emitting layer. Highly luminescent and air-stable formamidinium lead halide perovskite quantum dots using high-melting-point ligands have been synthesized. Through compositional engineering, the emission spectra are readily tunable over the entire visible spectral region of 409− 817 nm. The photoluminescence of FAPbX 3 nanocrystals has narrow emission line widths of 21−34 nm, high quantum yields of up to 88%, and a photoluminescence lifetime of 54.6−68.6 ns for single halide FAPbBr 3 , which could be stable for several months. We have demonstrated the fabrication of highly efficient formamidinium lead halide perovskite quantum dot-based green-light-emitting diodes with a moderately high luminance of 33993 cd m −2 , current efficiency of 20.3 cd A −1 , and moderately high maximum external quantum efficiency of 4.07%.

incorporated into graphene to harvest more photons. [4][5][6][7][8][9][10][11][12][13][14] These graphene photodetectors include metal graphene contact photodetectors, [4] plasmonics resonators to graphene, [5,6] photodetector based on vertical p-n graphene junctions, [7] photodetectors based on graphene field-effect transistors, [8][9][10] photodetectors coupling with microcavities, [11] and photodetector based on hybrid graphene-QD. [12][13][14] These works indicate great significance for the application of graphene in optical detecting field. Among them, the device combining quantum dots and graphene has achieved the highest response rate and quantum efficiency. [15] Perovskites quantum dots (PQDs), [16] whose three dimensions are all in the nanoscale, combined unique optical and electrical properties and solution-processed advantages. The band gaps could be easily tuned by adjusting the dot size and components. [17] The photodetectors based on PQDs have already outperformed conventional photodetectors in many aspects, including low-cost room-temperature device fabrication via solution processing, flexible substrate compatibility, high responsivity, and broadband spectral sensitivity. Recently, solution-processed organic-inorganic perovskite (ABX 3 , where A = CH NH 3 3 + (MA) or NH 2 CHCH + (FA), B = Pb 2+ or Sn 2+ and X = Cl − , Br − , and I − ) are emerging as promising semiconductors, illustrating a fast increase of light-to-electricity conversion efficiency through judicious optimizations to over 20%. [18][19][20] Recently, Liu et al. fabricated superior performance photodetector based on large-area single-crystalline MAPbX 3 perovskite wafer. [21,22] Compared with MAPbX 3 materials, FAPbX 3 was found to be an even better optoelectronic material with longer carrier time and diffusion lengths. [23,24] In this paper, we report a photodetector with high responsivity and external quantum efficiency (EQE) by combining single-layer graphene with FAPbBr 3 QDs. In this device, graphene provides conductive channels with high carrier mobility, while PQDs act as a strong light absorber. We present a hybrid FAPbBr 3 QD-graphene photodetector that exhibits a high photoresponsivity of ≈1.15 × 10 5 AW −1 , and a high EQE of ≈3.42 × 10 7 %. The high responsivity and EQE not only originate from the high photoelectric conversion efficiency of Highly performance photodetector requires a wide range of responses of the incident photons and converts them to electrical signals efficiently. Here, a photodetector based on formamidinium lead halide perovskite quantum dots (e.g., FAPbBr 3 QDs)-graphene hybrid, aiming to take the both advantages of the two constituents. The FAPbBr 3 QD-graphene layer not only benefits from the high mobility and wide spectral absorption of the graphene material but also from the long charge carrier lifetime and low dark carrier concentration of the FAPbBr 3 QDs. The photodetector based on FAPbBr 3 QD-graphene hybrid exhibits a broad spectral photoresponse ranging from 405 to 980 nm. A photoresponsiv...