217 research outputs found

    Supplementary document for Optical bistability and flip-flop function in feedback Fano laser - 6832232.pdf

    No full text
    Supplemental Document: Optical bistability and flip-flop function in feedback Fano lase

    Integrating Down-Shifting and Down-Conversion into Metal–Organic Frameworks to Enhance the Spectral Conversion for Solar Cells

    No full text
    Luminescent spectral conversion, including down-conversion (DC) and down-shifting (DS) is a potential route to overcome the spectral mismatch between solar photons and the semiconductor energy gap. Here, we introduce metal organic frameworks (MOFs) that integrate DC and DS processes into one system. Three different MOFs (Gd­(BTC)­(<b>1</b>), Gd­(BPT)­(<b>2</b>), and Gd­(OBT)­(<b>3</b>)) were synthesized doped with lanthanide ions couples. The DS–DC synergistic fluorescent processes were observed in all the MOFs. The overall absorption and near-infrared (NIR) emission intensity are dramatically enhanced (by factors of ∼4 800 and 550) due to the DS-sensitized effect for DC. As for DS process, the DC-bridge effect is quantified for the first time by comparing the NIR quantum yield (QY<sub>NIR</sub>). Benefiting from the bridge effect, QY<sub>NIR</sub> (5.30%) of <b>Dy0.01Yb0.10-3</b> is increased around 3 times greater than the system without DC process, and it is close to the highest value reported for the C–H bond containing Yb<sup>3+</sup> emitter. Our study demonstrated that MOFs can be regarded as easily prepared, environmentally friendly and efficient spectral conversion materials to improve the photon-response for c-Si solar cells

    Hydropower generation coefficients.

    No full text
    <p>Hydropower generation coefficients.</p

    An enhanced artificial bee colony algorithm (EABC) for solving dispatching of hydro-thermal system (DHTS) problem

    No full text
    <div><p>The dispatching of hydro-thermal system is a nonlinear programming problem with multiple constraints and high dimensions and the solution techniques of the model have been a hotspot in research. Based on the advantage of that the artificial bee colony algorithm (ABC) can efficiently solve the high-dimensional problem, an improved artificial bee colony algorithm has been proposed to solve DHTS problem in this paper. The improvements of the proposed algorithm include two aspects. On one hand, local search can be guided in efficiency by the information of the global optimal solution and its gradient in each generation. The global optimal solution improves the search efficiency of the algorithm but loses diversity, while the gradient can weaken the loss of diversity caused by the global optimal solution. On the other hand, inspired by genetic algorithm, the nectar resource which has not been updated in limit generation is transformed to a new one by using selection, crossover and mutation, which can ensure individual diversity and make full use of prior information for improving the global search ability of the algorithm. The two improvements of ABC algorithm are proved to be effective via a classical numeral example at last. Among which the genetic operator for the promotion of the ABC algorithm’s performance is significant. The results are also compared with those of other state-of-the-art algorithms, the enhanced ABC algorithm has general advantages in minimum cost, average cost and maximum cost which shows its usability and effectiveness. The achievements in this paper provide a new method for solving the DHTS problems, and also offer a novel reference for the improvement of mechanism and the application of algorithms.</p></div

    Atomic Structure of Ultrathin Gold Nanowires

    No full text
    Understanding of the atomic structure and stability of nanowires (NWs) is critical for their applications in nanotechnology, especially when the diameter of NWs reduces to ultrathin scale (1–2 nm). Here, using aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM), we report a detailed atomic structure study of the ultrathin Au NWs, which are synthesized using a silane-mediated approach. The NWs contain large amounts of generalized stacking fault defects. These defects evolve upon sustained electron exposure, and simultaneously the NWs undergo necking and breaking. Quantitative strain analysis reveals the key role of strain in the breakdown process. Besides, ligand-like morphology is observed at the surface of the NWs, indicating the possibility of using AC-HRTEM for surface ligand imaging. Moreover, the coalescence dynamic of ultrathin Au NWs is demonstrated by in situ observations. This work provides a comprehensive understanding of the structure of ultrathin metal NWs at atomic-scale and could have important implications for their applications

    Table_1_Association between statin use and acute pulmonary embolism in intensive care unit patients with sepsis: a retrospective cohort study.docx

    No full text
    IntroductionAcute pulmonary embolism (APE) is a life-threatening medical condition that is frequently encountered and associated with significant incidence and mortality rates, posing a substantial threat to patients’ well-being and quality of life. Sepsis is prominent independent risk factor for the development of APE. Despite recent investigations indicating a reduced APE risk through statin therapy, its impact on patients with sepsis and APE remains unresolved.MethodsThe Medical Information Mart for Intensive Care (MIMIC)-IV database was utilized to identify patients diagnosed with sepsis and APE, irrespective of statin treatment status, as part of this study. The primary study aim was to assess the risk of APE, which was analyzed using multivariate logistic regression models.ResultsThe study encompassed a total of 16,633 participants, with an average age of 64.8 ± 16.2 years. Multivariate logistic regression revealed that septic patients receiving statin therapy in the intensive care unit (ICU) exhibited a 33% reduction in the risk of developing APE (OR = 0.67, 95% CI: 0.52–0.86, p DiscussionThe results of the study provide compelling evidence in favor of administering statins to septic patients as a prophylactic measure against APE, given that statins may reduce the risk of developing APE, and their anti-APE effect appears to be dose-dependent. Nonetheless, future randomized controlled trials are needed to validate these results.</p

    The detailed steps of initial flow processing.

    No full text
    <p>The detailed steps of initial flow processing.</p

    The optimization processes of the optimal solution with different algorithms.

    No full text
    <p>The optimization processes of the optimal solution with different algorithms.</p

    The system daily hourly loads (MW).

    No full text
    <p>The system daily hourly loads (MW).</p

    Room-Temperature Dynamics of Vanishing Copper Nanoparticles Supported on Silica

    Get PDF
    In heterogeneous catalysis, a nanoparticle (NP) system has immediate chemical surroundings with which its interaction needs to be considered, as nanoparticles are typically loaded onto certain supports. Beyond what is known about these interactions, dynamic atomic interactions between the nanoparticle and support could result from the increased energetics at the nanoscale. Here, we show that the dynamic response of atoms in copper nanoparticles to the underlying silica support at room temperature and ambient atmosphere results in the complete disappearance of supported nanoparticles over the course of only a few weeks. A quantitative study of copper nanoparticles at various size regimes (6–17 nm) revealed the significance of size-dependent nanoparticle energetics to the interaction with the support. Extended X-ray absorption fine structure is used to show that copper atoms could readily diffuse into the support to be locally surrounded by oxygen and silicon with structurally disordered outer coordination shells. Increased energetic states at the nanoscale and the energetically favorable configuration of individual copper atoms within silica, identified through EXAFS, are suggested as the cause of nanoparticle disappearance. This unexpected observation opens up new questions as to how nanoparticles interact with surrounding environments that could fundamentally change our conventional view of supported nanoparticle systems
    • …
    corecore