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This work designed a simple, sensitive, low-cost, and disposable electrochemical platform for the detection of antibiotic rifampicin (RIF) by using a hollow manganese oxide@mesoporous silica oxide ([Mn.sub.3][O.sub.4]@Si[O.sub.2]) core-shell nanohybrid as sensitive material. The [Mn.sub.3][O.sub.4]@Si[O.sub.2] core-shell nanohybrid, prepared by a facile polyacrylic acid soft templating method, was applied to modify a homemade carbon paste microelectrode, which provided a feasible pathway for electron transfer of RIF due to the low density, large surface area, excellent loading capacity, high permeability, and abundant amount of active sites. The electrocatalytic behavior was further used for sensitive detection of RIF by square wave voltammetry. Under optimal conditions, the calibration curve was linear in the range from 30 nmol/L to 3.0 µmol/L. The electrochemical method showed good stability, reproducibility, and selectivity. It could effectively be applied to the determination of RIF in human serum and urine samples. Key words: rifampicin, hollow manganese oxide, mesoporous silica oxide, core-shell, electrochemical determination. Dans le cadre de ces travaux, nous avons concu une plateforme electrochimique simple, sensible, peu couteuse et jetable pour la detection de la rifampicine (RIF), un antibiotique, en utilisant comme materiau sensible des particules creuses nanohybrides de type creur-coquille composees d'oxyde de manganese et de silice ([Mn.sub.3][O.sub.4]@Si[O.sub.2]). Par une methode aisee de synthese en moule souple d'acide polyacrylique, nous avons fabrique les particules nanohybrides creur-coquille de [Mn.sub.3][O.sub.4]@Si[O.sub.2] que nous avons appliquees a une microelectrode a pate de carbone, de fabrication artisanale, afin de la modifier. De fait, cette microelectrode constituait une voie possible pour le transfert d'electrons de la RIF en raison de sa faible densite, de sa grande surface de contact, de son excellente capacite d'adsorption, de sa grande permeabilite et de son abondance de sites actifs. Nous avons ensuite utilise ce comportement electrocatalytique pour la detection sensible de la RIF par voltamperometrie a ondes carrees. En conditions optimales, la courbe de calibration etait lineaire dans l'intervalle allant de 30 nmol/L a 3,0 µmol/L. Cette methode electrochimique presentait des bonnes stabilite, reproductibilite et selectivite. Elle pourrait etre efficacement appliquee au dosage de la RIF dans des echantillons humains de serum et d'urine. [Traduit par la Redaction] Mots-cles: rifampicine, nanoparticules creuses d'oxyde de manganese, silice mesoporeuse, creur-coquille, dosage electrochimique., Introduction During the past two decades, microscopic materials have experienced a great structural evolution from simple to complex because they always show a strong correlation between their geometry and their [...]

Digitalization of government is a crucial strategy for enhancing national competitiveness and improving public services in numerous countries. This study introduced a quasi-natural experiment in China to evaluate the impact of a country's digital government policy on entrepreneurship. Using city-level data and regression analysis, we find that implementing the policy increases the number of newly registered firms by 0.0028 per 10,000 working-age labours. The study also examines potential mechanisms for this effect and finds evidence that the policy improves government efficiency, reduces risk-seeking behaviours of local government, and promotes access to financial resources. This study's findings contribute to research on digital government initiatives in developing countries and can inform future policy decisions. • Digital government policies can positively affect entrepreneurship. • Mechanisms for this effect are improving government efficiency, reducing risk-seeking behaviors, and access to financial resources. • Better marketability can strengthen the effects. [ABSTRACT FROM AUTHOR]

Establishing an optimal operation model of water resources is a crucial mean to promote the social and economic development in the Jiaodong area, where water resources are seriously deficient. Constraints of the optimal operation model mainly include water balance constraint, discharge capacity constraint, and constraint on the full utilization of operating water. For water transfer projects that have been in operation for decades, the parameters of these constraints, such as Discharge Capacity (DC), Water Conveyance Efficiency (WCE), Evapotranspiration (E), and Water Supply Volume (WSV), have changed from their original design values, which in turn affect the results of the operation model. In order to address the uncertainties caused by corresponding parameters, according to the characteristics of each parameter, an Interval-Chance Constrained Programming (ICCP) model for the Jiaodong Water Transfer Project was proposed. Interval Programming (IP) and Chance-Constrained Programming (CCP) were used to optimize the parameters of constraints involving WCE, DC, E, and WSV. Then, the Sobol method was used to analyze the sensitivity of each parameter to the operating objective function. The results reveal that (1) total water shortage ratio decreased by [14.82%, 17.26%], [14.81%, 17.25%], and [14.82%, 17.26%], respectively, under the incoming water condition of 50%, 75%, and 95%, indicating that ICCP model can adequately consider complex uncertainties and effectively alleviate water shortage; (2) WCE and DC are important parameters for optimal operation model of water resources, and therefore, channels should be regularly maintained to ensure that WCE and DC would not reduce; (3) Decision variables in this study are in the form of intervals, which are more reasonable because they provide more decision-making options to managers. [ABSTRACT FROM AUTHOR]

The corrosion properties of aluminum-lithium (AleLi) alloys, which are potential materials used to construct for tanks of liquid rockets or missiles, are essential for safe propellant storage and transport. In order to manifest the corrosion resistance of the 2195 AleLi alloy in practical propellant tanks filled with N2O4, the alloy was soaked in 30% nitric acid solution, an accelerating corrosion environment, to test its corrosion behavior. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize microstructure and corrosion morphology of the alloy. Focused ion beam (FIB), combined with SEM, was used to demonstrate localized corrosion features and the propagation of corrosion pathways beneath the alloy surface. It was found that the corrosion network was formed with most intergranular corrosion and sparse intragranular corrosion. Additionally, the distribution and number of intermetallic particles influenced the localized corrosion degree and the direction of corrosion pathways. Aggregated particles made corrosion pathways continuously and caused more severe corrosion. The results from this work were valid and useful to corrosion prevention and protection for storage safety on propellant tanks in N2O4. [ABSTRACT FROM AUTHOR]