9 research outputs found

    BICYCLE SHARING IN CHINA: PAST, PRESENT, AND FUTURE

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    This paper systematically explicates the historical developmental stages of China’s bicycle sharing economy including current and future business models. This paper also identifies problems that exist in the evolution of China’s bicycle sharing and provides potential solutions. Furthermore, it proposes a fifth-generation bicycle sharing model, the “intelligent dock-less bicycle sharing” model and analyzes its characteristics and development. The paper concludes with a discussion on the limitations of the study and future research directions

    Development of UHF Micromechanical Resonators and Arrays Based on Silicon-OnInsulator (SOI) Technology

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    A novel micromachining technology on SOI substrates is presented that is capable of producing on-chip high-Q resonators and resonator arrays equipped with high aspect-ratio (30:1) microstructures and nano-gap capacitive transducers filled with high-k dielectrics. The newly developed IC-compatible MEMS microfabrication process consists of merely three standard photolithography steps, which is much simpler than the other SOI-based resonator device technologies. In order to achieve the optimum performance and yield of the resonators and resonator arrays, this SOI-based fabrication process has been carefully designed and investigated step by step. For capacitively-transduced extensional mode (e.g., radial-contour and wine-glass mode) resonators, formation of nano-scale capacitive gaps and large resonator-to-electrode overlap area is essential for reducing the motional resistance Rx and DC bias voltage by strengthening the capacitive transduction. Atomic Layer Deposition (ALD) technology with superb conformability and uniformity as well as outstanding thickness controllability is used to deposit the ultra-thin layer (~10 nm) of high-k dielectric material that acts as the solid capacitive gaps, which allows the mass production of on-chip capacitively-transduced resonators and resonator arrays with greatly enhanced electromechancial coupling coefficient, and thus lower motional resistance and DC bias voltage. Using this technique, high-Q micromechanical resonators and resonator arrays on SOI substrates operating at ultra-high frequencies (UHF) have been developed. The ultimate goal of this project is to implement on-chip narrow-band micromechanical filters with unprecedented frequency selectivity and ultra-low insertion loss. By fine-tuning the nonlinear characteristics of the capacitive transducers enabled by the new SOI technology, novel on-chip mechanical signal processors for frequency manipulation, such as mixer and multiplier, will be investigated

    Development of UHF Micromechanical Resonators and Arrays Based on Silicon-OnInsulator (SOI) Technology

    Get PDF
    A novel micromachining technology on SOI substrates is presented that is capable of producing on-chip high-Q resonators and resonator arrays equipped with high aspect-ratio (30:1) microstructures and nano-gap capacitive transducers filled with high-k dielectrics. The newly developed IC-compatible MEMS microfabrication process consists of merely three standard photolithography steps, which is much simpler than the other SOI-based resonator device technologies. In order to achieve the optimum performance and yield of the resonators and resonator arrays, this SOI-based fabrication process has been carefully designed and investigated step by step. For capacitively-transduced extensional mode (e.g., radial-contour and wine-glass mode) resonators, formation of nano-scale capacitive gaps and large resonator-to-electrode overlap area is essential for reducing the motional resistance Rx and DC bias voltage by strengthening the capacitive transduction. Atomic Layer Deposition (ALD) technology with superb conformability and uniformity as well as outstanding thickness controllability is used to deposit the ultra-thin layer (~10 nm) of high-k dielectric material that acts as the solid capacitive gaps, which allows the mass production of on-chip capacitively-transduced resonators and resonator arrays with greatly enhanced electromechancial coupling coefficient, and thus lower motional resistance and DC bias voltage. Using this technique, high-Q micromechanical resonators and resonator arrays on SOI substrates operating at ultra-high frequencies (UHF) have been developed. The ultimate goal of this project is to implement on-chip narrow-band micromechanical filters with unprecedented frequency selectivity and ultra-low insertion loss. By fine-tuning the nonlinear characteristics of the capacitive transducers enabled by the new SOI technology, novel on-chip mechanical signal processors for frequency manipulation, such as mixer and multiplier, will be investigated

    Location Model for Distribution Centers for Fulfilling Electronic Orders of Fresh Foods under Uncertain Demand

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    The problem of locating distribution centers for delivering fresh food as a part of electronic commerce is a strategic decision problem for enterprises. This paper establishes a model for locating distribution centers that considers the uncertainty of customer demands for fresh goods in terms of time-sensitiveness and freshness. Based on the methodology of robust optimization in dealing with uncertain problems, this paper optimizes the location model in discrete demand probabilistic scenarios. In this paper, an improved fruit fly optimization algorithm is proposed to solve the distribution center location problem. An example is given to show that the proposed model and algorithm are robust and can effectively handle the complications caused by uncertain demand. The model proposed in this paper proves valuable both theoretically and practically in the selection of locations of distribution centers

    Genome-Wide Identification, Characterization, and Expression Pattern of <i>MYB</i> Gene Family in <i>Melastoma candidum</i>

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    The MYB gene family is significant in plants, playing a role in numerous plant development processes, including metabolism, hormone signal transduction, cell identity, and biotic and abiotic stresses. Due to the recent availability of the Melastoma candidum genome, this is the first time that the MYB gene family has been identified in this species. This study identified 421 MYB gene members in the M. candidum genome using the HMMER search and BLASTp method. These MYBs were further divided into 10 sub-types, including R2R3, R-R, CPC-like, CCA1-like, TBP-like, R1R2R3, I-box, atypical MYB, MYB-CC, and MYB-like. Domain and conservation analyses revealed that each type of MYB was characterized by a different number and combination of SANTs/myb DNA-binding domains. Collinearity analysis revealed several gene duplication events within the MYB gene family. The Ka to Ks ratio suggested that most of the MYB genes underwent purifying selection during the evolution process. Phylogenetic analysis among three species confirmed our findings and displayed the evolutionary relationship of MYB genes in different species. RNA-seq of three developmental stages of flowers and WGCNA analysis identified McMYB113h, McMYB21b, and McGLK1c as playing a pivotal role during flower development in M. candidum. Finally, we conducted qRT-PCR experiments for 20 flower-development-related MYBs across 9 tissues to illustrate their expression patterns in M. candidum. This study establishes a foundation for exploring MYB gene resources and their potential applications in related industries of M. candidum

    Topical administration of tranexamic acid reduces postoperative blood loss and inflammatory response in knee arthroscopic arthrolysis: a retrospective comparative study

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    Abstract Background Knee arthroscopic arthrolysis serves as an effective treatment for knee arthrofibrosis. However, hemarthrosis is the most common complication in arthroscopic surgery, which has potential adverse effects on postoperative rehabilitation. The purpose of this study was to evaluate the effects of topical tranexamic acid (TXA) in knee arthroscopic arthrolysis. Methods A total of 87 patients with knee arthrofibrosis who underwent arthroscopic arthrolysis from September 2019 to June 2021 were eligible for this retrospective review. Patients in the TXA group (n = 47) received topical administration of TXA (50 mL, 10 mg/mL) at the end of the surgery, and patients in the control group (n = 40) received no TXA. The postoperative drainage volumes, hematologic levels, inflammatory marker levels, knee range of motion (ROM), visual analog scale (VAS) pain scores, Lysholm knee scores and complications were compared between the two groups. The curative effect of each group was calculated according to Judet’s criteria. Results The mean drainage volumes on postoperative day (POD) 1 and POD 2, and total drainage volume were significantly lower in the TXA group than in the control group (P < 0.001 for all). The TXA group had significantly lower postoperative CRP and IL-6 levels on POD 1 and POD 2, and at postoperative week (POW) 1 and POW 2 than the control group. The VAS pain scores in the TXA group were significantly lower on POD 1 and POD 2, and at POW 1 and POW 2 than those in the control group (P < 0.001 for all). Patients in the TXA group showed better postoperative ROM and Lysholm knee scores at POW 1 and POW 2. No patient had any complications such as deep venous thrombosis (DVT) or infection. The excellent and good rates of knee arthroscopic arthrolysis were comparable between the two groups at the sixth postoperative month (P = 0.536). Conclusions Topical administration of TXA in knee arthroscopic arthrolysis can reduce postoperative blood loss and inflammatory response, alleviate early postoperative pain, increase early postoperative knee ROM, and improve early postoperative knee function without increased risks
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