18 research outputs found

    A cognitive evaluation and equity-based perspective of pay for performance on job performance: A meta-analysis and path model

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    Pay for performance, as one of the most important means of motivating employees, has attracted the attention of many scholars and managers. However, controversy has continued regarding whether it promotes or undermines job performance. Drawing on a meta-analysis of 108 independent samples (N = 71,438) from 100 articles, we found that pay for performance was positively related to job performance. That pay for performance had a more substantial positive effect on task performance than contextual performance in workplace settings. From the cognitive evaluation perspective, we found that pay for performance enhanced employees' task performance and contextual performance by enhancing intrinsic motivation and weakened task performance and contextual performance by increasing employee pressure. From the equity perspective, our results indicated that the relationship between pay for performance and task performance was partially mediated by employee perceptions of distributive justice and procedural justice, with distributive justice having a more substantial mediating effect than procedural justice. However, the relationship between pay for performance and contextual performance was only partially mediated by procedural justice. Further tests of moderating effects indicated that the varying impacts of pay for performance are contingent on measures of pay for performance and national culture. The findings contributed to understanding the complex mechanisms and boundary conditions of pay-for-performance's effects on job performance, which provided insights for organizations to maximize its positive effects

    Tuning crystal-phase of bimetallic single-nanoparticle for catalytic hydrogenation

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    Bimetallic nanoparticles afford geometric variation and electron redistribution via strong metal-metal interactions that substantially promote the activity and selectivity in catalysis. Quantitatively describing the atomic configuration of the catalytically active sites, however, is experimentally challenged by the averaging ensemble effect that is caused by the interplay between particle size and crystal-phase at elevated temperatures and under reactive gases. Here, we report that the intrinsic activity of the body-centered cubic PdCu nanoparticle, for acetylene hydrogenation, is one order of magnitude greater than that of the face-centered cubic one. This finding is based on precisely identifying the atomic structures of the active sites over the same-sized but crystal-phase-varied single-particles. The densely-populated Pd-Cu bond on the chemically ordered nanoparticle possesses isolated Pd site with a lower coordination number and a high-lying valence d-band center, and thus greatly expedites the dissociation of H2_2 over Pd atom and efficiently accommodates the activated H atoms on the particle top/subsurfaces

    RNA-binding protein RALY reprogrammes mitochondrial metabolism via mediating miRNA processing in colorectal cancer

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    Objective: Dysregulated cellular metabolism is a distinct hallmark of human colorectal cancer (CRC). However, metabolic programme rewiring during tumour progression has yet to be fully understood. Design: We analysed altered gene signatures during colorectal tumour progression, and used a complex of molecular and metabolic assays to study the regulation of metabolism in CRC cell lines, human patient-derived xenograft mouse models and tumour organoid models. Results: We identified a novel RNA-binding protein, RALY (also known as hnRNPCL2), that is highly associated with colorectal tumour aggressiveness. RALY acts as a key regulatory component in the Drosha complex, and promotes the post-transcriptional processing of a specific subset of miRNAs (miR-483, miR-676 and miR-877). These miRNAs systematically downregulate the expression of the metabolism-associated genes (ATP5I, ATP5G1, ATP5G3 and CYC1) and thereby reprogramme mitochondrial metabolism in the cancer cell. Analysis of The Cancer Genome Atlas (TCGA) reveals that increased levels of RALY are associated with poor prognosis in the patients with CRC expressing low levels of mitochondrion-associated genes. Mechanistically, induced processing of these miRNAs is facilitated by their N6-methyladenosine switch under reactive oxygen species (ROS) stress. Inhibition of the m6A methylation abolishes the RALY recognition of the terminal loop of the pri-miRNAs. Knockdown of RALY inhibits colorectal tumour growth and progression in vivo and in organoid models. Conclusions: Collectively, our results reveal a critical metabolism-centric role of RALY in tumour progression, which may lead to cancer therapeutics targeting RALY for treating CRC

    Numerical investigation for the fatigue performance of reinforced concrete beams strengthened with external prestressed HFRP sheet

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    External FRP (Fiber Reinforced Polymer) strengthening method has been considered to be an effective way to restore or increase the capacity of RC (Reinforced Concrete) beams. This study focuses on numerical simulating the fatigue performance of HFRP (Hybrid Fiber Reinforced Polymer) strengthened RC beam. Beams are pre-cracked first, then strengthened by HFRP, and subjected to fatigue loading. The test variable is the prestress of HFRP. Stress distribution and damage development of pre-cracking, strengthening and fatigue loading process are analyzed. The user-subroutine UMAT in Abaqus is used for implementation of the constitutive models of component materials. The simulation results show good agreements with experimental data. The failure of both reference beam and strengthened beams is found caused by fatigue fracture of the longitudinal steel bar. Therefore, the stress amplitude of the longitudinal steel bar is the dominant factor of the fatigue life of RC beams. Prestressed HFRP can significantly reduce the stress magnitude of longitudinal steel bar and suppress crack propagation, thus improve the fatigue life of the strengthened RC beam. In an appropriate range, elevating prestress level can prolong fatigue life of strengthened RC beam

    Aerodynamic modification and optimization of intermediate pressure compressor in marine intercooled recuperated gas turbine

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    The intercooling recuperated cycle (ICR) is commonly employed in marine gas turbines to enhance thermal efficiency. However, the addition of an intercooler may lead to the increased dimension and structural complexity of marine ICR gas turbines. To address this issue, we propose an improved configuration of the intermediate pressure compressor – an axial-centrifugal combined compressor (ACC) with high inlet hub-tip ratio and high flow rate. The aerodynamic performance of the ACC at multi-operating points is optimized via an improved free-form deformation method for the parametric modeling of the flow paths and blades of turbomachinery. The result indicates that the number of stages decreases from 6 to 3 and the axial length is reduced by 38.3% after modification. The adiabatic efficiency of the optimized ACC at the design and low-speed operating points is improved by 1.18% and 6.48% respectively. Additionally, the ACC redesigned scheme can reduce the axial length, maximize the flow path space utilization, enhance the stage load capacity, and significantly improve the low-speed performance. This provides a reference for developing advanced marine ICR gas turbines with high power and low fuel consumption

    Impact of city lockdown on the air quality of COVID-19-hit of Wuhan city

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    A series of strict lockdownmeasures were implemented in the areas of China worst affected by coronavirus disease 19, including Wuhan, to prevent the disease spreading. The lockdown had a substantial environmental impact, because traffic pollution and industrial emissions are important factors affecting air quality and public health in the region. After the lockdown, the average monthly air quality index (AQI) in Wuhan was 59.7, which is 33.9% lower than that before the lockdown(January 23, 2020) and 47.5% lower than that during the corresponding period (113.6) from 2015 to 2019. Compared with the conditions before the lockdown, fine particulate matter (PM2.5) decreased by 36.9% and remained the main pollutant. Nitrogen dioxide (NO2) showed the largest decrease of approximately 53.3%, and ozone (O-3) increased by 116.6%. The proportions of fixed-source emissions and transported external-source emissions in this area increased. After the lockdown, O-3 pollution was highly negatively correlated with the NO2 concentration, and the radiation increase caused by the PM2.5 reduction was not the main reason for the increase in O-3. This indicates that the generation of secondary pollutants is influenced by multiple factors and is not only governed by emission reduction. (C) 2020 Elsevier B.V. All rights reserved

    Rapeseed (Brassica napus L.) Primary Ramification Morphological Structural Model Based on Biomass

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    International audiencePrimary ramification morphogenesis has a significant influence on the yield of rapeseed. In order to quantify the relationship between rapeseed architecture indices and the organ biomass, a rapeseed primary ramification structural model based on biomass were presented. Intended to explain effects of cultivars and environmental conditions on rapeseed PR morphogenesis. The outdoor experiment with cultivars: Ningyou 18 (V1, conventional), Ningyou 16 (V2, conventional) and Ningza 19 (V3, hybrid), and designed treatment of cultivar-fertilizer, cultivar-fertilizer-density, and cultivar tests in 2011–2012 and 2012–2013. The experimental result showing that the leaf blade length of PR, leaf blade width of PR, leaf blade bowstring length of PR, PR length, and PR diameter from 2011 to 2012 were goodness, and their da values and RMSE values were −1.900 cm, 5.033 cm (n = 125); −0.055 cm, 3.233 cm (n = 117); 0.274 cm, 2.810 cm (n = 87); −0.720 cm, 3.272 cm (n = 90); 0.374 cm, 0.778 cm (n = 514); 0.137 cm, 1.193 cm (n = 514); 0.806 cm, 8.990 cm (n = 145); and −0.025 cm, 0.102 cm (n = 153), respectively. The correlations between observation and simulation in the morphological indices were significant at P < 0.001, but the dap values were <5 % for the second leaves length and the third leaves length, leaf blade bowstring length, PR length, and PR diameter, which indicated that the model’s accuracy was high. The models established in this paper had definite mechanism and interpretation, and the impact factors of N, the ratio of the leaf length to leaf dry weight of primary ramification (PRRLW), and the partitioning coefficient of leaf blade dry weight of primary ramification (PRCPLB) were presented, enabled to develop a link between the plant biomass and its morphogenesis. Thus, the rapeseed growth model and the rapeseed morphological model can be combined through organ biomass, which set a reference for the establishment of FSPMs of rapeseed

    Compact Circular-Shaped MIMO Antenna Covers UWB Bandwidth With Four Frequently-Used Band-Notched Characteristics for Multi-Scenario Applications

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    In this work, a tapered fed circular-shaped monopole antenna for ultrawideband (UWB) applications integrated with four frequently-used band-notched properties is designed. By the design of notch structures inside the radiation patch, on the feedline, and on either side of the feedline, four notch bands covering from3.3&#x2013;3.8 GHz, 5.25&#x2013;5.75 GHz, 7.25&#x2013;7.75 GHz, and 8.01&#x2013;8.5 GHz are obtained possibly, which suppress the interference with WiMax, WLAN, satellite downlink and ITU applications, respectively. Based on these, the proposed antenna is operable from 1.4 GHz to 25 GHz with maximum coupling value of &#x2212;20 dB covering almost operational band, and it has compact dimensions of 43×36×1.5943\times 36\times 1.59 mm3. Evolution and accomplishment of final results, involving the reduction of mutual coupling suppression, are illustrated gradually. The property of the monopole antenna considering reflection coefficient, isolation among different ports, realized gain, radiation pattern, efficiency, and envelope correlation coefficient (ECC) are studied. Moreover, experimental results are verified with the simulations. In addition, using the antenna inserted in chest badge, the chance of infection will greatly reduce. Ultimate, the proposed MIMO monopole antenna has a potential application in the medical, high precision machining, and biopharming relevant domains

    Biomass-Based Leaf Curvilinear Model for Rapeseed (Brassica napus L.)

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    International audienceLeaf is one of the most important photosynthetic organs of rapeseed (Brassica napus L.). To quantify relationships between the leaf curve and the corresponding leaf biomass for rapeseed on main stem, this paper presents a biomass-based leaf curvilinear model for rapeseed. Various model variables, including leaf length, bowstring length, tangential angle, and bowstring angle, were parameterized based on data derived from the field experiments with varieties, fertilizer, and transplanting densities during 2011 to 2012, and 2012 to 2013 growing seasons. And then we analysed the biological significance of curvilinear equation for straight leaves, constructed the straight leaf probabilistic model on main stem, quantified the relationship between leaf curvature and the corresponding leaf biomass, and constructed the leaf curvilinear model based on the assumption and verification of the curvilinear equation form for curving leaf. The probability of straight leaf can be quantified with piecewise function according to the different trend in the normalized leaf ranks ((0, 0.4], and (0.4, 1]). The leaf curvature decreased with the increasing of leaf biomass, and can be described with reciprocal function. The curve of straight leaf and the curving leaf can be simulated by linear equation and the quadratic function, respectively. Our models were validated with the independent dataset from the field experiment, and the results indicated that the model could effectively predict the straight leaf probability and leaf curvature, which would be useful for linking the rapeseed growth model with the rapeseed morphological model, and set the stage for the development of functional-structural rapeseed models

    Oblique penetration mechanism of hybrid composite laminates

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    Abstract Hybrid fiber composites are widely used to improve the anti-penetration performance. Carbon/Kevlar hybrid composites are used in aircrafts and safety devices, thanks to the strong toughness of Kevlar fibers and high strength of carbon fibers. In the present work, the contact force of hybrid composites under oblique impact is derived. The viscoelastic constitutive model of Kevlar layer is investigated and the dissipation energies of composites for different high velocity oblique impacts are simulated. The results show that hybrid composites have good bullet-proof performance, the contact forces are fluctuant in short time and the frictional dissipation energy allows us to prevent penetration
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