Scheduling Performance Evaluation of Logistics Service Supply Chain Based on the Dynamic Index Weight

Scheduling is crucial to the operation of logistics service supply chain (LSSC), so scientific performance evaluation method is required to evaluate the scheduling performance. Different from general project performance evaluation, scheduling activities are usually continuous and multiperiod. Therefore, the weight of scheduling performance evaluation index is not unchanged, but dynamically varied. In this paper, the factors that influence the scheduling performance are analyzed in three levels which are strategic environment, operating process, and scheduling results. Based on these three levels, the scheduling performance evaluation index system of LSSC is established. In all, a new performance evaluation method proposed based on dynamic index weight will have three innovation points. Firstly, a multiphase dynamic interaction method is introduced to improve the quality of quantification. Secondly, due to the large quantity of second-level indexes and the requirements of dynamic weight adjustment, the maximum attribute deviation method is introduced to determine weight of second-level indexes, which can remove the uncertainty of subjective factors. Thirdly, an adjustment coefficient method based on set-valued statistics is introduced to determine the first-level indexes weight. In the end, an application example from a logistics company in China is given to illustrate the effectiveness of the proposed method

Golden Ratio Genetic Algorithm Based Approach for Modelling and Analysis of the Capacity Expansion of Urban Road Traffic Network

This paper presents the modelling and analysis of the capacity expansion of urban road traffic network (ICURTN). Thebilevel programming model is first employed to model the ICURTN, in which the utility of the entire network is maximized with the optimal utility of travelers’ route choice. Then, an improved hybrid genetic algorithm integrated with golden ratio (HGAGR) is developed to enhance the local search of simple genetic algorithms, and the proposed capacity expansion model is solved by the combination of the HGAGR and the Frank-Wolfe algorithm. Taking the traditional one-way network and bidirectional network as the study case, three numerical calculations are conducted to validate the presented model and algorithm, and the primary influencing factors on extended capacity model are analyzed. The calculation results indicate that capacity expansion of road network is an effective measure to enlarge the capacity of urban road network, especially on the condition of limited construction budget; the average computation time of the HGAGR is 122 seconds, which meets the real-time demand in the evaluation of the road network capacity

Research on seismic response of new lining structured of shallow double-arch tunnels under unsymmetrical pressure

A physical test model of a new lining structure for a shallow double-arch tunnels under unsymmetrical pressure with a scale of 1:20 was designed and manufactured. Kobe seismic waves and EI seismic waves were selected as the loading waves and a large-scale shaking table test was carried out. The acceleration and dynamic strain response of shallow double-arch tunnels under unsymmetrical pressure under different seismic wave types and seismic intensities are studied. The results show: Under different seismic wave excitations, only the horizontal acceleration amplification factor of the left-hole vault, right-hole invert and the top right of the mid-partition is less than 1, and the horizontal acceleration amplification factors of other measurement points are all greater than 1. The measurement points with relatively large horizontal acceleration response are the left-hole shoulder, the top left of the mid-partition, the right-hole vault and shoulder; The overall response of the right half-arch of the left-hole is greater than the left half-arch of the left-hole, and the overall response of the left half-arch of the right-hole is greater than the right half-arch of the right-hole. The measured points in the left half-arch of the left-hole and the right half-arch of the right-hole have small differences in acceleration response; The effects of Kobe wave on horizontal acceleration and vertical acceleration are greater than EI wave, and the average value of the vertical acceleration response of the lining is greater than the average value of the horizontal acceleration response. With the increase of seismic intensity, the larger the acceleration amplification factor is, the greater the increase is; Under the action of different seismic waves, the seismic wave excitation has a greater impact on the dynamic strain response of the left-hole, and less impact on the right-hole. Among them, the strain value of the left-hole shoulder, left-hole invert and the top left of the mid-partition is much larger than the other measurement points, the trend of the right-hole is relatively gentle, and the strain values of the shoulder are slightly larger. The research conclusions have certain guidance and reference value for the seismic design of shallow double-arch tunnels under unsymmetrical pressure

Conduction modulation of solution-processed two-dimensional materials

Solution-processed two-dimensional (2D) materials hold promise for their scalable applications. However, the random, fragmented nature of the solution-processed nanoflakes and the poor percolative conduction through their discrete networks limit the performance of the enabled devices. To overcome the problem, we report conduction modulation of the solution-processed 2D materials via the Stark effect. Using liquid-phase exfoliated molybdenum disulfide (MoS2) as an example, we demonstrate nonlinear conduction modulation with a switching ratio of >105 by the local fields from the interfacial ferroelectric P(VDF-TrFE). Through density-functional theory calculations and in situ Raman scattering and photoluminescence spectroscopic analysis, we understand the modulation arises from a charge redistribution in the solution-processed MoS2. Beyond MoS2, we show the modulation may be viable for the other solution-processed 2D materials and low-dimensional materials. The effective modulation can open their electronic device applications

Fascinating bifunctional electrocatalytic activity via a mesoporous structured FeMnO3@ZrO2 matrix as an efficient cathode for Li-O2 batteries

Nonaqueous Li-O2 batteries have remarkable potential for use in future-generation sustainable green energy storage systems. Perovskites of the type ABO3 provide bifunctional electrocatalytic activity superior to that of dual mixed-metal oxides due to the presence of crystallographic defects and oxygen vacancies, arising from the multivalency of the A and B cations. In this study, we used a facile hydrothermal method with an ammonia solution to modify coralline-like ZrO2 with Fe0.5Mn0.5O3 (FeMnO3) and graphene nanosheets (GNSs). The porous structure of the resulting ZrO2@FeMnO3/GNS system featured a high surface area and large volume, thereby exposing a great number of active sites. X-ray photoelectron spectroscopy revealed that the surface of the as-synthesized FeMnO3@ZrO2/GNS cathode material was rich with oxygen vacancies (i.e., a huge quantity of defects). This coralline-like bifunctional electrocatalyst possessed effective redox capability between Li2O2 and O2 as a result of its excellent catalytic activity in the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). We examined the charge/discharge behavior of corresponding electrodes (EL-cell type for Li-O2 battery) in the voltage range of 2.0-4.5 V (vs Li/Li+). The synergistic effects of the high catalytic ability and coralline-like microstructure of our ZrO2@FeMnO3/GNS catalyst for Li-O2 batteries resulted in its superior rate capability and excellent long-term cyclability, sustaining 100 cycles at 100 mA g-1 with a limited capacity of 1000 mAh g-1. The cell overpotential was ∼0.14 V when adding LiI as a redox mediator, resulting in a more practical Li-O2 battery with the ZrO2@FeMnO3/GNS catalyst. Therefore, ZrO2@FeMnO3/GNS catalysts having distinctive coralline-like structures can display outstanding bifunctional catalytic activity and electrical conductivity, suggesting great potential for enhanced Li-O2 battery applications

Preparation of g-C3N4/ZIF-8/PVDF–modified Li anode for all-solid-state Li metal batteries

All-Solid-state lithium metal batteries (ASSLMBs) are promising next-generation energy storage devices. However, the formation of lithium (Li) dendrites in ASSLMBs limits their applications. In this study, we used an inorganic/organic mixture of graphitic carbon nitride (g-C3N4), zinc-based Zeolitic Imidazolate Framework-8 (ZIF-8), and poly(vinylidene difluoride) (PVDF)—g-C3N4/ZIF-8/PVDF (g-CNZP)—to modify the surface of a lithium metal anode (LMA). The 2032-type coin cell was assembled based on a lithium Nafion (LiNf)–coated NCM811 (denoted as LiNf@NCM811) cathode, inorganic/organic mixture modified Li metal anode (LMA) (denoted g-CNZP@Li), and a LiNf-coated Li6.05Ga0.25La3Zr2O11.8F0.2 ([email protected]) filler in bilayer hybrid solid electrolyte (Bi-HSE). The coin cell was charged between 2.8 and 4.2 V at 0.5C exhibited an initial specific discharge capacity of 134.45 mAh g−1 and retained 86.1 % of its capacity after 280 cycles at 30 °C. The average coulombic efficiency of the cell was approximately 99.8 %. Furthermore, the high-voltage (2.8–4.5 V, at a rate of 0.2C) result also delivered an initial specific discharge capacity of 194.3 mAh g−1 and, after 100 cycles, maintained 81.8 % of its initial capacity at room temperature. The presence of the nanosheet/nanoparticle composite coating material on the LMA surface suppressed Li dendrite growth and enhanced the compatibility between the LMA and Bi-HSE membrane. In addition, the in-situ formation of Li3N on the solid electrolyte interface (SEI) layer improved the ionic conductivity and ensured intimate interfacial contact during cycling. Therefore, these novel bi-layered fabrication strategies for obtaining hybrid/composite solid electrolyte membranes and modifying LMA surfaces via 2D g-C3N4 material with ZIF-8 MOFs and PVDF composites appear to have applicability in the preparation of very safe high-voltage cathodes for ASSLMBs

Energy evolution mechanism during rockburst development in structures of surrounding rocks of deep rockburst-prone roadways in coal mines

Influenced by the deep high-stress environment, geological structures, and mining disturbance in coal mines, the frequency of rockburst disasters in roadways is increasing. This research analyzed energy evolution characteristics during rockburst development in the elastic bearing zone and energy conversion in the plastic failure zone. The critical energy criteria for structural instability of roadway surrounding rocks were deduced. Numerical software was also applied to simulate the energy evolution during rockburst development in surrounding rocks of rockburst-prone roadways under conditions of different mining depths and coal pillar widths. The occurrence mechanism of rockburst deep in coal mines was analyzed from the perspective of energy in structures of deep roadway surrounding rock in coal mines. The research results show that the critical energy criteria are closely related to the elastic strain energy stored in deep roadway surrounding rocks and the energy absorbed by support systems. The impact energy in roadways is directly proportional to the square of the stress concentration factor k. Moreover, as the mining depth increases, the location of the peak point of maximum energy density gradually shifts to coal ahead of the working face. The larger the mining depth is, the more significantly the energy density is influenced by advanced abutment pressure of the working face and the wider the affected area is. With the increment of the coal pillar width, the distance from the peak point of energy density to the roadway boundary enlarges abruptly at first and then slowly, and the critical coal pillar width for gentle change in the distance is 30 m. Changes in the peak elastic energy density in coal pillars with the coal pillar width can be divided into four stages: the slow increase stage, abrupt increase stage, abrupt decrease stage, and slow decrease stage. The elastic energy density is distributed asymmetrically in deep roadway surrounding rocks in coal mines. Under the action of structures of roadway surrounding rocks, energy evolution in these structures differs greatly during rockburst development under conditions of different coal pillar widths. This research provides an important theoretical basis for the support of rockburst-prone roadways during deep coal mining