Search

During the last train period, passengers will not successfully reach their destination if the timetables of the various transfer station lines are not coordinated. This paper proposes a general model to optimize the last train timetables of urban rail networks and maximize origin-destination (OD) accessibility for metro networks during the last train period. By using a generalized cost function, all transportation activities involved in an urban rail network are effectively described, and a generalized cost function is established for the last train as a criterion for its accessibility. A mixed-integer programming model that pays more attention to passengers' effective travel routes and accessibility of the entire OD route is proposed. A genetic algorithm combined with a K-shortest path algorithm is developed to calculate a rescheduling solution within a satisfactory running time (e.g., 35 min). Finally, comparative experiments are conducted using the Xi'an urban rail network as a case study. The results show that the objective function of OD accessibility is more favorable to last train passengers than to the number of successful transfer passengers at transfer stations. This increases the number of passengers successfully arriving at their destination by 12.03%. The proposed methodology assist in cost-effective coordination of the last train timetables and make accurate recommendations to improve passenger OD accessibility using information guidance. [ABSTRACT FROM AUTHOR]

Urea electrooxidation has received considerable attention because of its tremendous practical application in environmental protection and energy regeneration. The catalytic performance of urea oxidation as an electrochemical reaction is highly determined by catalysts, and Ni-based catalysts have been intensively studied due to their low cost, facile structure tuning, and easy active phase formation based on the electrochemical-chemical mechanism. The Ni catalyst for urea oxidation can be largely improved by rational surface/interface structure optimization via various surface engineering approaches that provide more active sites, desirable crystal phase, and defects promoting the mass and electron transfer for the catalytic reaction. Due to significant recent advances, herein, we review the recent advances of heterostructured Ni-based active catalysts for urea electrolysis. The concerns about general heterostructured catalyst engineering principles in terms of crystal phase orientation, increased bond polarity, high-valent Ni formation, increased active surface area, electronic effect, and ensemble effect are first presented, and then theoretical analysis for the promotion effect is briefly demonstrated. Following this, specific hetero-structured Ni-based catalysts classified according to hetero-element doping, hetero-metallic alloying, and multi-component heterostructure construction are mainly discussed and analyzed with some typical examples. Finally, we present the problems, challenges, and perspective comments for the subject topic. It is noted that each component has its functionality to contribute to catalytic reactions, and the study on rationally integrated components to fully make use of their strengths and make up for each other's weaknesses is still a great challenge. Hopefully, this review could be helpful and instructive for the literature survey of heterostructured Ni-based catalysts in urea electrolysis. [ABSTRACT FROM AUTHOR]

A one-way traffic strategy is widely used in densely populated urban areas to improve traffic efficiency, but its environmental impacts remain largely unclear. This study investigated the effects of a one-way traffic strategy on vehicle emissions along a busy traffic corridor in Xi’an, China. This was done by integrating the traffic flow model calibrated by onsite traffic data and the emission model. The detour distance estimation method was proposed so that the emission trade-offs between increased vehicle miles traveled (VMTs) and improved traffic efficiency on one-way traffic corridors could be uncovered. Empirical results showed that one-way traffic cut down the total CO2 emissions by 11.8%, and reduced the CO, hydrocarbon (HC), and NOx emissions by 4.7%–25.0%. However, such emission reduction capacity gradually weakened and even completely dissipated with the increase of traffic demand on the corridor. When the road volume-tocapacity ratio (V/C > 0.87), one-way traffic was no longer a greener traffic organization. With the promotion of mitigation policies and technologies, one-way traffic is expected to further reduce CO2 emissions by 4.7%–10.9% and CO, HC, and NOx emissions by 8.4%– 41.1%. In addition, there was a total of 456 vehicles detours with an overall detour distance of 316.8 km, which resulted in a doubling of the emissions of detour vehicles. Although the implementation of one-way traffic brings environmental benefits, the detour problem should also be taken seriously. This study provides convincing evidence for understanding the emission changes on traffic corridors caused by one-way traffic conversion to support the promotion of eco-friendly traffic organization for realizing the goal of carbon peaking. [ABSTRACT FROM AUTHOR]

Tubular particleboard is made of wood shavings through high-temperature extrusion. It is a particleboard with round thru-holes aligned lengthwise in the board. This paper discussed the development of multidimensional-interface extrusion technology. Process parameters were determined for the production of five different particleboard thicknesses of 24 mm, 28 mm, 35 mm, 40 mm, and 60 mm. The authors also tested the physical and lengthwise mechanical properties of the tubular particleboards. The manufactured tubular particleboards had the following properties, with respect to the above thicknesses: MOR of 4.9 to 2.2 MPa; MOE of 380 to 250 MPa; IB of 0.54 to 0.37 MPa; TS of 1.7 to 0.8%; and LDC of 9.1 to 5.2%. All met the values specified in the standards LY/T 1856 (2009) and GB/T 34717 (2017). MOR was ≥1 and ≥1.7; IB was ≥0.1 and ≥0.17; TS was ≤5; LDC was ≤15. It was concluded that as the thickness of the board increased, the mechanical properties decreased, but the physical properties increased. When compared to traditional extruded tubular particleboards, the multidimensional-interface extruded tubular particleboards had excellent physical and lengthwise mechanical properties. In addition, the lengthwise mechanical properties were similar to flat-pressed tubular particleboard, and ultra-thick particleboard can be produced. [ABSTRACT FROM AUTHOR]

Activated sericite was prepared by thermal modification, acid activation and sodium modification, and it was characterized by X-ray diffraction (XRD) analysis, differential scanning calorimetry (DSC), N2 adsorption test, thermo-gravimetric analysis (TGA), nuclear magnetic resonance (NMR), and scanning electron microscope (SEM). The results indicated that the crystallinity of raw sericite decreased after thermal modification; the pores with sizes between 5 nm to 10 nm of thermal-modified sericite have collapsed and the surface area increased after thermal modification. The dissolving-out amount of Al3+ reached ca. 31 mg/g in the optimal processing conditions during acid activation; cation exchange capacity (CEC) of acid-treated sericite increased to 56.37 mmol/100 g meq/g after sodium modification compared with that of raw sericite (7.42 mmol/100 g). The activated sericite is a promising matrix for clay-polymer nanocomposites. [ABSTRACT FROM AUTHOR]

In order to reduce the primary particle size of zinc oxide (ZnO) and eliminate the agglomeration phenomenon to form a monodisperse state, Zn2+ was loaded on the surface of amorphous silica (SiO2) by the hydrogen bond association between hydroxyl groups in the hydrothermal process. After calcining the precursors, dehydration condensation among hydroxyl groups occurred and ZnO nanoparticles supported on amorphous SiO2 (ZnO-SiO2) were prepared. Furthermore, the SEM and TEM observations showed that ZnO nanoparticles with a particle size of 3-8 nm were uniformly and dispersedly loaded on the surface of amorphous SiO2. Compared with pure ZnO, ZnO-SiO2 showed a much better antibacterial performance in the minimum inhibitory concentration (MIC) test and the antibacterial properties of the paint adding ZnO-SiO2 composite. [ABSTRACT FROM AUTHOR]

Evolocumab has been considered as an efficacious, safe and promising therapeutic modality for hypercholesterolemia and is associated with cardiovascular diseases. The efficacy and safety of two different doses of evolocumab were evaluated and the safety of evolocumab was compared with that of a placebo and ezetimibe. PubMed and EMBASE databases were searched and randomized controlled trials that examined the effect and safety of evolomucab compared with a placebo and ezetimibe were retrieved. Two authors independently performed article reviews and study quality evaluations. Odds ratios (ORs) were calculated using a fixed or random-effects model [95% confidence intervals (CIs)]. In the direct comparison, a significant reduction was observed in the muscle-associated events compared with ezetimibe [OR=0.54 (95% CI, 0.31-0.93); P (Z)=0.03, P (Q)=0.43, I2=0%]. In the adjusted indirect comparison of evolocumab 140 mg Q2W vs. evolocumab 420 mg Q4W, no significant differences in efficacy [OR=1.04 (95% CI, 0.55-1.99); P (Z)=0.90] or adverse events [OR=1.08 (95% CI, 0.66-1.74); P (Z)=0.76] were identified. The funnel plots of these direct comparison studies indicated that there was no publication bias. The results of this meta-analysis demonstrate that evolocumab significantly reduced low-density lipoprotein cholesterol levels, and no difference was noted between evolocumab 140 mg Q2W and evolocumab 420 mg Q4W. Furthermore, evolocumab had fewer muscle-associated events than ezetimibe. [ABSTRACT FROM AUTHOR]