Transport Path Research Articles

Light-absorbing black carbon and brown carbon components of smoke aerosol from DSCOVR EPIC measurements over North America and central Africa

Abstract. Wildfires and agricultural burning generate seemingly increasing smoke aerosol emissions, impacting societal and natural ecosystems. To understand smoke's effects on climate and public health, we analyzed the spatiotemporal distribution of smoke aerosols, focusing on two major light-absorbing components, namely black carbon (BC) and brown carbon (BrC) aerosols. Using NASA's Earth Polychromatic Imaging Camera (EPIC) instrument aboard NOAA's Deep Space Climate Observatory (DSCOVR) spacecraft, we inferred BC and BrC volume fractions and particle mass concentrations based on spectral absorption provided by the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm with 1–2 h temporal resolution and ∼ 10 km spatial resolution over North America and central Africa. Our analyses of regional smoke properties reveal distinct characteristics for aerosol optical depth (AOD) at 443 nm, spectral single-scattering albedo (SSA), aerosol layer height (ALH), and BC and BrC amounts. Smoke aerosols in North America showed extremely high AOD up to 6, with elevated ALH (6–7 km) and significant BrC components up to 250 mg m−2 along the transport paths, whereas the smoke aerosols in central Africa exhibited stronger light absorption (i.e., lower SSA) and lower AOD, resulting in higher-BC mass concentrations and similar BrC mass concentrations than the cases in North America. Seasonal burning source locations in central Africa, following the seasonal shift in the Intertropical Convergence Zone and diurnal variations in smoke amounts, were also captured. A comparison of retrieved AOD443, SSA443, SSA680, and ALH with collocated AERONET and CALIOP measurements shows agreement with RMSE values of 0.2, 0.03–0.04, 0.02–0.04, and 0.8–1.3 km, respectively. An analysis of the spatiotemporal average reveals distinct geographical characteristics in smoke properties closely linked to burning types and meteorological conditions. Forest wildfires over western North America generated smoke with a small-BC volume fraction of 0.011 and a high ALH with large variability (2.2 ± 1.2 km), whereas smoke from wildfires and agricultural burning over Mexico region shows more absorption and low ALH. Smoke from savanna fires over central Africa had the most absorption, with a high-BC volume fraction (0.015) and low ALH with a small variation (1.8 ± 0.6 km) among the analyzed regions. Tropical forest smoke was less absorbing and had a high variance in ALH. We also quantify the estimation uncertainties related to the assumptions of BC and BrC refractive indices. The MAIAC EPIC smoke properties with BC and BrC volume and mass fractions and assessment of the layer height provide observational constraints for radiative forcing modeling and air quality and health studies.

Solvothermal synthesis and enhanced electrochromic properties of coal-based reduced graphene oxide and covalent organic framework electrochromic composite films containing triphenylamine unit

Two-dimension covalent frameworks (2D COFs) with reversible redox units show the potential in the field of photo-electronic functional materials because of their rich electron transport path and reversible redox characteristic. However, the pure organic conjugated system of COF results in poor electrical conductivity and weak cyclic performance. In this work, tris (4-aminophenyl) amine and 4,4-biphenyldiformaldehyde (TABP) COF electrochromic film with triphenylamine (TPA) active unit was synthesized by a solvothermal method in Teflon-lined reactor. And then the TABP-COF/coal-based reduced graphene oxide (C-rGO) film was prepared by the one pot method. C-rGO provides the growth substrate and electron transport path for COF. Taixi anthracite with a high degree of graphitization also contributes to the preparation of GO. The electrochemical and electrochromic properties of TABP-COF and TABP-COF/C-rGO were studied and they could be switched reversibly from yellow and brown. Relative to TABP-COF, the impedance and response time of composite decrease and the contrast of composite increases. Moreover, TABP-COF/C-rGO exhibits the excellent stability, which can remain 80.1 % initial contrast after 5000 s cycle.

Assessment of Measured Mixing Time in a Water Model of Eccentric Gas-Stirred Ladle with a Low Gas Flow Rate: Tendency of Salt Solution Tracer Dispersions

The measurement of mixing time in a water model of soft-stirring steelmaking ladles is practically facing a problem of bad repeatability. This uncertainty severely affects both the understandings of transport phenomenon in ladles and the measurement accuracy. Scaled down by a ratio of 1:4, a water model based on an industrial 260-ton ladle is used. This paper studies the transport process paths and mixing time of salt solution tracers in the water model of eccentric gas-stirred ladles with a low gas flow rate. After a large number of repeated experiments, the different transport paths of the tracer and the error of the mixing time in each transport path are discussed and compared with the numerical simulation results. The results of a large number of repeated experiments on the water model show that there are five transport paths for the tracer in the ladle. The tracer of the first path is mainly transported by the left-side main circulation flow, which is identical to the numerical simulation results. The tracer of the second and third paths are also mainly transported by the left-side circulation flow, but bifurcations occur when the tracer in the middle area is transported downward. In the third path, the portion and intensity of the tracer transferring to the right side from the central region is higher than in the second path. The fourth path is that the tracer is transported downward from the left, middle, and right sides with a similar intensity at the same time. While the tracer in the fifth path is mainly transported on the right side, and the tracer forms a clockwise circulation flow on the right side. The mixing times from the first transport path to the fifth transport path are 158.3 s, 149.7 s, 171.7 s, 134 s and 95.7 s, respectively, among which the third transport path and the fifth transport path are the maximum and minimum values among all transport paths. The error between the mixing time and the averaged mixing time at each monitoring point in the five transport paths of the tracer is between −34.7% and 40.9%. Furthermore, the error of the averaged mixing time of each path and the path-based average value is between 5.5% and 32.6%.

Clay mineral composition and transport pattern of surface sediments in the Ganges Submarine Delta

The Ganges Submarine Delta is a key land-sea transitional area in the northeastern Indian Ocean. An understanding of sediment distribution, provenance, and transportation in this area is of great importance for understanding its sedimentary environment and the sediment “source-sink” system of the northeastern Indian Ocean. This study aimed to identify the provenances and transport patterns of fine-grained sediments in the Ganges Submarine Delta through analysis of the grain size and clay mineral content of 84 surface sediment samples. Sediment illite, chlorite, kaolinite, and smectite contents were ∼66%, 18%, 11%, and 5%, respectively. Sediment illite content decreased from north to south; smectite and chlorite decreased and increased from northwest to southeast, respectively; kaolinite content was highest in the south. Spatial cluster analysis of the four clay minerals grouped the study area into two provinces: province I in the north is characterized by a clay mineral assemblage similar to that of the Ganges-Brahmaputra rivers; province II in the south is characterized by deep water and changes to clay mineral characteristics due to the mixing of material originating from the Indian Peninsula. This study used the illite/(smectite + chlorite + kaolinite) and kaolinite/illite ratios to discuss sediment transport paths in the two provinces. Himalayan material is widely distributed throughout the study area, and mainly transported from the estuary to the southwestern area by the tides, plume, and monsoons; sediments of the Mahanadi river are transported from southwest to northeast by the southwest monsoon, thereby affecting the sediment composition of province II.

Climatic significance of clay minerals in Cenozoic marine and lacustrine sediments

Abstract In sediments, clay minerals are mainly detrital. Formed by continental weathering, they are carried by surface transport predominantly by rivers, glaciers and, to a lesser extent, winds to the adjacent sedimentary basins and then are redistributed by oceanic currents. In a sedimentary core, the variability in the clay mineral assemblages reflects either variable physical and chemical weathering conditions in the watershed, typically with a significant link to climatic conditions, or changes in the mineral source, the latter being associated with various transport agents. When different sources are involved, a combination of mineralogical and geochemical proxies allows us to trace the detrital provenance, but they also indirectly provide valuable information on transport pathways and palaeocurrents. This manuscript reviews several examples from the literature and ongoing research on clay mineral variability in marine or lacustrine sedimentary records and interprets them in terms of: (1) climate control at different timescales, from the Neogene to the Quaternary; and (2) transport paths. Examples are selected to review the various clay-derived proxies in existence.

Tracing the electron transport behavior in quantum-dot light-emitting diodes via single photon counting technique

The electron injection and transport behavior are of vital importance to the performance of quantum-dot light-emitting diodes. By simultaneously measuring the electroluminescence-photoluminescence of the quantum-dot light-emitting diodes, we identify the presence of leakage electrons which leads to the discrepancy of the electroluminescence and the photoluminescence roll-off. To trace the transport paths of the leakage electrons, a single photon counting technique is developed. This technique enables us to detect the weak photon signals and thus provides a means to visualize the electron transport paths at different voltages. The results show that, the electrons, except those recombining within the quantum-dots, leak to the hole transport layer or recombine at the hole transport layer/quantum-dot interface, thus leading to the reduction of efficiency. By reducing the amount of leakage electrons, quantum-dot light-emitting diode with an internal power conversion efficiency of over 98% can be achieved.

Optimizing self-sensing performance of conductive mortar via gradation of graphene coated aggregate

With the increasing focus on structural health monitoring of concrete during its service life, self-sensing functional concrete has emerged as an effective method for real-time detection and assessment of structural conditions. We recently proposed a new methodology of preparing conductive cementitious mortar with graphene-coated aggregates (Gr@Ag). Instead of the traditional approach, where conductive fillers are directly intermixed and uniformly distributed in the binding matrix, the development of Gr@Ag has created a more efficient path for electron transport through the connections of aggregates. The main objective of this study is to understand the effect of aggregate gradation on the electrical performances of conductive mortars, and the piezoresistivity is optimized by adjusting the aggregate packing. Electrochemical impedance spectroscopy was employed to investigate the underlying mechanisms of how aggregate gradation affects the mortar's electrical conductivity. It was found that both the internal resistance and resistivity of the conductive mortar considerably decreased with the reduction in Gr@Ag particle size. The contribution of conductive sand to the conductivity of mortar can reach 80.89–92.36 %, effectively transforming the conductive path from a disconnected state to a connected state. Reducing the particle size of the conductive aggregates contributes to an increase in particle contact rate, with the particle contact rate reaching up to 59 %. The presence of completely isolated conductive aggregates is noticeably reduced. As the particle size decreases, there is a significant reduction in mechanical performance. The conductive aggregates become relatively isolated from the matrix, and both the size of the conductive aggregates and the interfacial transition zone play vital roles to affect the mechanical properties.

Perovskite quantum dots/WSe2 mixed-dimensional van der Waals heterostructure for photoelectric enhancement and polarization sensitivity

The performance of some heterostructures based devices is limited by strong interlayer coupling and limited electronic structure modulation. Meanwhile, the detection of polarized light holds great significance in future photoelectric fields such as cryptography. In this work, zero-dimensional/two-dimensional (0D/2D) mixed-dimensional van der Waals heterostructure (MvdWH) polarization-sensitive photodetector composed of solution-synthesized CH3NH3PbI3(MAPbI3) perovskite quantum dots (QDs) and chemical vapor deposition (CVD)-grown WSe2 was designed, forming a type II band structure. The MvdWH effectively enhance the carrier transmission rate, and improve the efficiency of charge separation, realizing an ultra-high responsiveness of 217.8 A/W and an ultrasensitive photodetectivity of 2.56 × 1011 Jones under 633 nm illumination. The device shows ultra-fast response times of 4.5/4.9 μs, which is due to the introduction of 0D QDs will shorten the electron transport path and reduces trap-mediated non-radiative recombination. Further, the in-plane anisotropy of MAPbI3 QDs was identified by angle-resolved absorption spectroscopy and angle-resolved polarization Raman spectroscopy, respectively. The MAPbI3/WSe2 device exhibits polarization-sensitive optoelectronic detection with an anisotropy ratio of 1.71, and powerful polarization-sensitive imaging ability, implying that MAPbI3 QDs endows the device with polarization detection and imaging capabilities. These results indicate that the construction of 0D/2D MvdWH opens a new avenue for ultrasensitive and polarization-sensitive photodetection, which depicts opportunities for designing multifunctional, high-performance imaging optoelectronic devices.

Fabrication of high-performance gas diffusion electrode via microporous layer surface morphology control

Enhancing the performance of membrane electrode assemblies (MEAs) that utilize gas diffusion electrodes (GDEs) to match those based on catalyst coated membranes (CCMs) is critical for the widespread application of GDE-based technologies in proton exchange membrane fuel cells (PEMFCs). The inferior interfaces between the catalyst layers and the proton exchange membranes (PEMs) within GDE-based MEAs result in lower performance. In this study, the microporous layer (MPL) surface morphology control was achieved through hot pressing possessing the advantages of convenient implementation and avoiding excessive ionomer introduction. This approach produces smoother surfaces and higher peeling strengths between GDEs and PEMs, indicating enhanced interfacial contact. The ohmic resistance decreased from 0.056 to 0.033 Ω cm2, while the cathode catalyst layer proton resistance decreased from 0.124 to 0.059 Ω cm2, suggesting that the proton conductivity across the layers and within the catalyst layers were both increased. Moreover, the catalytic activity and gas transport capability within the catalyst layers are marginally improved. Following the MPL surface morphology control, the peak power density of GDE-based MEA was improved by 23 %, comparable to that of the CCM-based MEA. Nevertheless, excessive hot-pressing pressure might block the water transport path, resulting in poor performance at high current density.

Large-Scale Network-Based Observations of a Saharan Dust Event across the European Continent in Spring 2022

Between 14 March and 21 April 2022, an extensive investigation of an extraordinary Saharan dust intrusion over Europe was performed based on lidar measurements obtained by the European Aerosol Research Lidar Network (EARLINET). The dust episode was divided into two distinct periods, one in March and one in April, characterized by different dust transport paths. The dust aerosol layers were studied over 18 EARLINET stations, examining aerosol characteristics during March and April in four different regions (M-I, M-II, M-III, and M-IV and A-I, A-II, A-III, and A-IV, respectively), focusing on parameters such as aerosol layer thickness, center of mass (CoM), lidar ratio (LR), particle linear depolarization ratio (PLDR), and Ångström exponents (ÅE). In March, regions exhibited varying dust geometrical and optical properties, with mean CoM values ranging from approximately 3.5 to 4.8 km, and mean LR values typically between 36 and 54 sr. PLDR values indicated the presence of both pure and mixed dust aerosols, with values ranging from 0.20 to 0.32 at 355 nm and 0.24 to 0.31 at 532 nm. ÅE values suggested a range of particle sizes, with some regions showing a predominance of coarse particles. Aerosol Optical Depth (AOD) simulations from the NAAPS model indicated significant dust activity across Europe, with AOD values reaching up to 1.60. In April, dust aerosol layers were observed between 3.2 to 5.2 km. Mean LR values typically ranged from 35 to 51 sr at both 355 nm and 532 nm, while PLDR values confirmed the presence of dust aerosols, with mean values between 0.22 and 0.31 at 355 nm and 0.25 to 0.31 at 532 nm. The ÅE values suggested a mixture of particle sizes. The AOD values in April were generally lower, not exceeding 0.8, indicating a less intense dust presence compared to March. The findings highlight spatial and temporal variations in aerosol characteristics across the regions, during the distinctive periods. From 15 to 16 March 2022, Saharan dust significantly reduced UV-B radiation by approximately 14% over the ATZ station (Athens, GR). Backward air mass trajectories showed that the dust originated from the Western and Central Sahara when, during this specific case, the air mass trajectories passed over GRA (Granada, ES) and PAY (Payerne, CH) before reaching ATZ, maintaining high relative humidity and almost stable aerosol properties throughout its transport. Lidar data revealed elevated aerosol backscatter (baer) and PLDR values, combined with low LR and ÅE values, indicative of pure dust aerosols.

A Path Planning Method Based on Hybrid Sand Cat Swarm Optimization Algorithm of Green Multimodal Transportation

Aiming at the difficulty of measuring various costs and time-consuming elements in multimodal transport, this paper constructs a green vehicle comprehensive multimodal transport model which incorporates transportation, transit, quality damage, fuel consumption, and carbon emission costs and proposes a hybrid embedded time window to calculate the time penalty cost in order to reflect the actual transport characteristics. Furthermore, in order to better solve the model, a hybrid sand cat swarm optimization (HSCSO) algorithm is proposed by introducing Logistic–Tent chaotic mapping and an adaptive lens opposition-based learning strategy to enhance the global search capability, and inspired by the swarm intelligence scheme, a momentum–bellicose strategy and an equilibrium crossover pool are introduced to improve the search efficiency and convergence ability. Through testing nine benchmark functions, the HSCSO algorithm exhibits superior convergence accuracy and speed in dealing with complex multi-dimensional problems. Based on the excellent global performance, the HSCSO algorithm was utilized for multimodal vehicle transportation in East China, and a path with a lower comprehensive cost was successfully planned, which proved the effectiveness of the HSCSO algorithm in green intermodal transport path planning.

Core-shell like rGO coated Co9S8 hollow dodecahedron for enhanced oxygen evolution reaction

The development of low-cost, high-activity, high-durability non-precious metal OER electrocatalysts is still the most critical bottleneck for the preparation of clean-energy by water splitting. In this thesis, the Co9S8@rGO heterogeneous interface was constructed to optimize the electron transport pathway and enhance the active site to improve the OER activity. The ZIF-67 dodecahedron was used as a template to prepare Co9S8 with a hollow dodecahedron structure using the hydrothermal method and annealing treatment to shorten the charge transport path and increase its specific surface area. Subsequently, a protective shell layer of rGO with good conductivity and stability was wrapped around the Co9S8 catalyst core by the construction of a Co9S8@rGO core-shell heterostructure. It was found that the 30 % Co9S8@rGO core-shell heterostructure not only reduced the overpotential (190 mV at 10 mA cm−2) and tafel slope (66.48 mV dec−1) but also improved the stability compared to Co9S8. The density of states and the Gibbs free energy of HO*, O* and HOO* intermediates of Co9S8@rGO were investigated by first-principles theoretical calculations according to density functional theory (DFT). The DFT calculation results showed that the Gibbs free energy (ΔG30) of Co9S8@rGO core-shell heterostructure was lower than that of Co9S8 in the rate-control step, which leaded to the decrease of overpotential and was beneficial to the OER reaction.

Significant performance enhancement of Zn-ion hybrid supercapacitors based on microwave-assisted pyrolyzed active carbon via synergistic effect of NaHCO3 activation and CNT networks

Zinc-ion hybrid supercapacitors (ZIHSCs) represents a promising technological approach for large-scale energy storage with the combined advantages of supercapacitors and zinc-ion batteries. Unfortunately, it is still challengeable to quickly fabricate low-cost, high-performance carbonaceous cathode materials at relatively low temperature. To address such issues, herein, taking waste Eucommia ulmoides Oliver (EUO) wood as an example, we present a novel microwave-assisted carbonization (MWC) approach at relatively low temperature to quickly prepare active carbon, and we present a synergistic strategy to significantly enhance the electrochemical performance by introducing sodium bicarbonate activation (SA) and constructing conductive carbon nanotubes (CNT) networks. The MWC-SA@CNT hybrid exhibits outstanding specific capacitance of 344.2 F/g at 0.2 A/g within three-electrode system, much better than conventional high-temperature pyrolyzed AC, MWC carbon, and MWC-SA carbon. The superior performance of MWC-SA@CNT can be attributed to the synergistic effect of its large specific surface area of 1102.7 m2/g, high mesoporous percentage of 53.5%, and rich –OH and CO groups due to microwave-assisted carbonization and sodium bicarbonate activation, and rich electron transport paths due to the presence of CNT networks. Furthermore, ZIHSCs assembled by MWC-SA@CNT cathode could delivers impressive performance with excellent capacity (194.37 mA h/g at current density of 1 A/g), energy density (142.30 Wh/kg), and durability (capacitance retention rate of 97.65% after 5000 cycles). This work offers a rapid and low-temperature method for preparing wood-based active carbon with rich nanopores and strong conductivity to improve performance of Zinc ion storage.

Simulation of hydrogen transportation development path and carbon emission reduction path based on LEAP model - A case study of Beijing-Tianjin-Hebei Region

Hydrogen-fuelled vehicles have attracted significant attention around the world recent years as the main form of hydrogen transportation. Chinese government in September 2020 has introduced corresponding supporting policies. In particular, Beijing-Tianjin-Hebei urban agglomeration is the first batch of pilot cities. To research the development of hydrogen transportation and carbon emission reduction paths in Beijing-Tianjin-Hebei urban agglomeration, we construct LEAP-Beijing-Tianjin-Hebei Urban Agglomeration Hydrogen Transportation model, and simulate it based on the scenario analysis method. The results show that the total hydrogen demand reaches 7,975,860 tonnes in the year 2060. And the freight transportation sector is the largest hydrogen consumer in transportation. For carbon emission reduction, transportation sector under different scenarios could achieve net-zero emission in year 2060, with total emission reduction 431.19 million metric tonnes. We suggest that the promotion of hydrogen transportation should be carried out in stages. Early large-scale development of hydrogen-fuelled vehicles in sectors such as passenger cars and specialized vehicles is not significant in emission reduction, and it is more appropriate to start with medium and large-sized commercial vehicles. Gradually extend to the whole transportation sector after the technology of hydrogen-fuelled vehicles is mature and the supply capacity of clean hydrogen is improved.

Plasmonic‐Promoted Interatomic Hot Carriers Regulation Enhanced Electrocatalytic Nitrogen Reduction Reaction

Utilizing hot carriers for efficient plasmonic‐mediated chemical reactions (PMCRs) to convert solar energy into secondary energy is one of the most feasible solutions to the global environmental and energy crisis. Finding a plasmonic heterogeneous nanostructure with a more efficient and reasonable hot carrier transport path without affecting the intrinsic plasmonic properties is still a major challenge that urgently needs to be solved in this field. Herein, the mechanism by which plasmonic‐promoted interatomic hot electron redistribution on the surface of Au3Cu alloy nanoparticles promotes the electrocatalytic nitrogen reduction reaction (ENRR) is successfully clarified. The localized surface plasmon resonance (LSPR) effect can boost the transfer of plasmonic hot electrons from Au atoms to Cu atoms, trigger the interatomic electron regulation of Au3Cu alloy nanoparticles, enhance the desorption of ammonia molecules, and increase the ammonia yield by approximately 93.9%. This work provides an important reference for rationally designing and utilizing the LSPR effect to efficiently regulate the distribution and mechanism of plasmonic hot carriers on the surface of heterogeneous alloy nanostructures.

Plasmon-Promoted Interatomic Hot Carriers Regulation Enhanced Electrocatalytic Nitrogen Reduction Reaction.

Utilizing hot carriers for efficient plasmon-mediated chemical reactions (PMCRs) to convert solar energy into secondary energy is one of the most feasible solutions to the global environmental and energy crisis. Finding a plasmonic heterogeneous nanostructure with a more efficient and reasonable hot carrier transport path without affecting the intrinsic plasmonic properties is still a major challenge that urgently needs to be solved in this field. Herein, the mechanism by which plasmon-promoted interatomic hot electron redistribution on the surface of Au3Cu alloy nanoparticles promotes the electrocatalytic nitrogen reduction reaction (ENRR) is successfully clarified. The localized surface plasmon resonance (LSPR) effect can boost the transfer of plasmon hot electrons from Au atoms to Cu atoms, trigger the interatomic electron regulation of Au3Cu alloy nanoparticles, enhance the desorption of ammonia molecules, and increase the ammonia yield by approximately 93.9 %. This work provides an important reference for rationally designing and utilizing the LSPR effect to efficiently regulate the distribution and mechanism of plasmon hot carriers on the surface of heterogeneous alloy nanostructures.

How Can the Filler-Polymer Interaction in Mixed Matrix Membranes Be Enhanced?

Mixed matrix membranes (MMMs) constitute a type of molecular separation membranes in which a nanomaterial type filler is dispersed in a given polymer to enhance its selective permeation ability. The key issue in MMMs is the establishing of a proper filler-polymer interaction to avoid non-selective transport paths while increasing permeability but also to improve other membrane properties such as aging and plasticization. Along the pass years several strategies have been applied to enhance the physicochemical interaction between the fillers (e.g. silicas, zeolites, porous coordination polymers, carbonaceous materials, etc.) and the membrane polymers: increase of external surface area, priming, use of intrinsically more compatible fillers, in situ synthesis of filler, in situ polymerization, polymer side-chain modification and post-synthetic modification of filler.

Multi-objective Optimization-Based Algorithm for Selecting the Optimal Path of Rural Multi-temperature Zone Cold Chain Dynamic Logistics Intermodal Transportation

The road network in rural areas is complex and the infrastructure is relatively backward. The multi-temperature zone cold chain logistics involves agricultural products with different temperature requirements, which requires considering the transportation cost, carbon emission cost, refrigeration cost, and time cost of different temperature zones during path planning, thereby increasing the difficulty of path planning. Therefore, a multi-objective optimization-based algorithm for selecting the optimal path of rural multi-temperature zone cold chain dynamic logistics intermodal transportation is proposed. Based on the analysis of the multi-temperature cold chain collection and distribution model based on multimodal transportation, a multi-objective optimization model is constructed. This model aims to minimize transportation costs, carbon emission costs, refrigeration costs, time costs, and maximize logistics quality, while satisfying constraints such as transfer schedule times, the number of transport mode conversions, transport mode selection, and time continuity. To solve this model, an improved NSGA-II algorithm is adopted, which combines an improved mutation operator, congestion distance calculation, and the C-W saving algorithm to achieve the optimal transport path solution. Additionally, ArcGIS software is used to implement the shortest path planning based on real road networks. The experimental results show that by selecting the road-rail combined transport mode and adopting the D1–D6–D10 transport path, it is possible to transport fresh agricultural products from location A to the distribution center at location B, with the lowest Pareto fitness value. Furthermore, the algorithm's effectiveness is further verified by completing the end-of-life fresh agricultural product distribution task with four multi-temperature refrigerated vehicles. The study also finds that extending or shortening the latest service time window for customers, although it leads to a decrease or increase in the optimal value of the algorithm's objective function, has little impact on the average distribution time and transport vehicles. These findings provide new theoretical and practical guidance for the path selection of multimodal transportation in multi-temperature cold chain logistics, with significant theoretical and application value.

Investigation of structural, optical, photocatalytic, and antibacterial properties of ZnO doped GO nanoparticles for environment applications.

As a result of their unique and novel properties, nanocomposites have found applications in a wide variety of fields. The purpose of this study is to demonstrate the ability to synthesize nanoparticles consisting of zinc oxide (ZnO) and graphene oxide (GO) via sol-gel techniques. An x-ray diffractometer (XRD) as well as a UV-visible spectrometer were used to determine the crystalline and optical characteristics of the prepared samples. A hexagonal wurtzite crystal structure was observed in both pure ZnO nanoparticles and those that contain GO based on XRD results. It was estimated that the average crystallite size is based on the broadening of x-ray lines. In comparison with pure ZnO, the antimicrobial properties were enhanced when GO was incorporated with ZnO. In addition, experiments on the absorption edge indicated the presence of a red shift as a result of the incorporation of GO. When GO is incorporated in quantitative amounts, the bandgap value of pure ZnO decreased. FTIR spectra exhibit a band of absorption at 486 cm-1, which confirms Zn-O stretching in both samples. SEM images reveal a random pattern of structural features on the surface of the prepared samples. According to the EDX spectrum, pure GO nanoparticles and those doped with ZnO contain 61%-64% zinc and 32%-34% oxygen, respectively. When annealed at a higher temperature, ZnO NPs produced more H2 with a narrower bandgap than before annealing. In addition, methyl blue (MB) was used as an example of an organic compound in order to investigate the potential photocatalytic properties of nanoparticles with ZnO doped GO. In addition to DPPH assays, ZnO nanoparticles and ZnO doped GO nanoparticles were tested for their ability to scavenge free radicals. Comparing ZnO doped GO NPs with pure ZnO, these nanoparticles showed increased antioxidant activity. Based on the increased zone of inhibition observed for pure ZnO and ZnO doped GO (5, 10, 50, and 100 mg/mL), the antibacterial activity of pure ZnO and ZnO doped GO is concentration dependent. A detailed discussion of the results of the study demonstrated that ZnO doped GO and pure ZnO are toxic in different ways depending on how long they survive in degreased Zebrafish embryos and how fast they decompose. RESEARCH HIGHLIGHTS: The scope of the manuscript was under the results of the study confirmed that both nanoparticles exhibited concentration dependent antioxidative activity. Determined that 89% of methyl orange dye can be degraded photocatalytically. ZnO nanoparticles were found to be 74.86% antioxidant at a concentration of 50 g/mL in the present study. At a concentration of 50 g/mL, ZnO doped GO NPs showed 79.1% antioxidant activity. Photocatalytic degradation mechanism scheme is implicit in the photoexcited charge carrier transportation path is observed for all the samples. Survival rate of zebrafish embryos was shown to decrease with increasing concentrations of ZnO and zinc oxide plus GO nanoparticles.

Reconfigurable acoustic topological valley-locked waveguide states transport based on nestable sonic crystals

Topological waveguide states in condensed matter physics systems show significant potential for applications, such as high-capacity information communication and energy regulation of complex physical fields owing to the phenomenon of large-area wave transport. The lack of tunability design for sonic crystals makes it difficult to change the structure and function of existing topological waveguide states transport structures after sample fabrication, especially in terms of the freedom of width and tunability on the transport path, and thus hinders further engineering applications of topological waveguide states. To address these challenges, the design method based on nested difference theory to achieve topological phase transitions in sonic crystals is proposed, which in turn leads to the construction of fully reconfigurable acoustic topological waveguide states and explores their potential applications. Firstly, a reconfigurable nested scatterer structure is designed, which is split into a snowflake-like core and an outer shell. This scatterer is demonstrated to be able to break the spatial inversion symmetry and realize the transition of sonic crystals between three valley topological phases by only changing the nesting mode of the nested outer shell. Based on reconfigurable sonic crystals, the fully reconfigurable acoustic topological valley-locked waveguide states are constructed. Simulations and experiments further confirm that such waveguides are characterized by high-capacity transport, acoustic focusing, and robust transport over large inflection corners. In addition, we explore the potential applications of reconfigurable waveguides for acoustic channels and acoustic logic gates. The precise distribution of the waveguide states energy is achieved in the acoustic channel by adjusting the rotation angle of the channel. Moreover, the logical computational relationships of the transport structure of the topological waveguide states are determined using different acoustic excitation modes. The excellent transport properties generated by fully reconfigurable acoustic topological waveguide states will have potential applications in both field enhancement and energy harvesting. This provides the possibility for the development of novel acoustic devices capable of modulating waves in complex physical scenarios.