•Construction of port and shipping logistics emergy ecological footprint model based on shanghai port logistics ecology.•Improved ecological footprint model increases port logistics eco-account.•The ...proportion distribution of ecological footprint of port and shipping logistics is analyzed.•It is found that the logistics of Shanghai port and navigation is still in ecological deficit.•Suggestions on the construction of port green logistics are put forward.
With the advent of economic globalization, port logistics industry in China has developed rapidly, but the energy consumption and pollution emissions brought by the development of port logistics are also increasing, which has seriously affected the regional environment. This study improves the traditional calculation method of ecological footprint based on the theory of emergy analysis and builds the emergy-ecological footprint (EEF) model of port logistics. Through data collection and analysis, the ecological situation of Shanghai port logistics from 2009 to 2018 is studied. The results show that the energy footprint of Shanghai port logistics is the largest component of the ecological footprint of port logistics, followed by the pollution footprint. Although the development of port water logistics promotes the development of natural resources and improves the ecological carrying capacity of port logistics, the ecological footprint is higher than the ecological carrying capacity, and Shanghai port logistics is still in an ecological deficit state. Therefore, this paper puts forward some strategies and suggestions to improve the ecological situation of Shanghai port logistics from the aspects of the formulation of laws and regulations, the improvement of port production and operation facilities, the improvement of collection and distribution structure and the strengthening of propaganda. Not only is it beneficial to the development of Shanghai green port logistics, but it also brings certain reference significance to the construction of other green ports.
A non-enzymatic glucose biofuel cell (GBFCs) with high-power density and adequate open-circuit potential in physiological environment is based on the improved hydrogen template electrodeposition of ...the platinum-nickel (PtNi) nanoalloys (the third step adopted a potential-step electrochemical synthesis instead of the conventional method). The morphology tests demonstrate that the highly porous Pt
x
Ni
1-x
nanoalloys exhibit broader pore-size distribution and larger specific electrochemically active surface area than the Pt monometallic nanostructures. Combined with cyclic voltammograms, polarization parameters and cell tests, degradation behavior measurements prove that the nanoalloy products display the excellent long-term stability and high electrocatalytic activity. Controlling the preparation conditions of the highly porous Pt
x
Ni
1-x
nanoalloys could control the morphology and nanostructure of the as-synthesis nanoalloys in order to improve the catalytic performance of these nanoalloys, which grants it great potentialities for controllable synthesis of electrocatalysts in the application of GBFCs.
Graphical abstract
Description
The highly porous platinum nickel nanoalloys are applied as both anode and cathode in the non-enzymatic glucose biofuel cell with high-power density and adequate open-circuit potential in physiological environment.
Thermally activated delayed fluorescent (TADF) materials are promising to overcome triplet-induced optical loss in the pursuit of electrically pumped organic lasers. However, population inversion is ...difficult to establish in these materials due to the severe suppression of triplet-to-singlet upconversion in their condensed states. In this work, we report thermally activated lasing in solution-processed coassembled microcrystals, where TADF dyes were uniformly dispersed into crystalline matrices to ensure an efficient reverse intersystem crossing (RISC). The dark-state triplet excitons harvested by the RISC were effectively converted into radiative singlet excitons, which subsequently participated in the population inversion to boost lasing with an unusual temperature dependence. The lasing wavelength was tuned over the full visible spectrum by doping various TADF laser dyes, owing to the excellent compatibility. Trichromatic TADF microlasers were precisely patterned into periodic pixelated arrays by a template-confined solution-growth method. With as-prepared TADF microlaser arrays as display panels, vivid laser displays were achieved under programmable excitation. These results offer valuable enlightenment to minimize triplet state-related energy losses toward high-performance lasers.
Metal‐organic frameworks (MOFs) have recently emerged as appealing platforms to construct microlasers owing to their compelling characters combining the excellent stability of inorganic materials and ...processable characters of organic materials. However, MOF microstructures developed thus far are generally composed of multiple edge boundaries due to their crystalline nature, which consequently raises significant scattering losses that are detrimental to lasing performance. In this work, we propose a strategy to overcome the above drawback by designing spherically shaped MOFs microcavities. Such spherical MOF microstructures are constructed by amorphizing MOFs with a topological distortion network through introducing flexible building blocks into the growth environment. With an ultra‐smooth surface and excellent circular boundaries, the acquired spherical microcavities possess a Q factor as high as ≈104 and can provide sufficient feedback for high‐quality single‐mode lasing oscillations. We hope that these results will pave an avenue for the construction of new types of flexible MOF‐based photonic components.
Amorphous spherically‐shaped metal‐organic framework (MOF) microcavities have been constructed by amorphizing MOFs with a topological distortion network through introducing flexible building blocks, which possess a Q factor as high as ≈104 and can provide sufficient feedback for high‐quality single‐mode lasing oscillations. The results will pave an avenue for the construction of new types of flexible MOFs‐based photonic components.
To solve the problem of long logistics delivery time in supply chain, a Mixed Integer Non-linear Program (MINLP) model is built by using Mixed Integer nonlinear programming theory. Firstly, the ...General algebraic modeling system (GAMS) is used to build the model to fully integrate each parameter of logistics transportation, the total distribution time of the supply chain network, the coverage radius of the logistics base, the number of users, the total capacity of the logistics base, the mode of railway and road transportation, the nonlinear programming model is built and solved by DICOPT solver in GAMS. The cost of logistics can be decreased, transportation time can be reduced, and the logistics system's operating efficiency can be increased in the long term with the help of this algorithm. The proper operation of the logistics system is critical in encouraging the supply chain circulation of various industries and has a direct impact on the society's economic development. The optimal logistics distribution plan with 5 logistics bases covered users of 18 and railway capacity of 2. With the same railway capacity and the same total budget, the larger the number of covered users, the greater the total distribution time increases, but the larger the total budget, the growth of the total distribution time slows down significantly. Experiments show that MINLP model can solve the problem of logistics-based layout optimization in nonlinear logistics management.
To investigate the effect of high temperature-water cooling repeated impact action on the tensile mechanical properties of granite, Brazilian splitting tests are conducted on granite discs after ...repeated treatment with high temperature water cooling on specimens from 250 to 650 °C, the load–displacement curves, tensile strength, average stiffness, crack evolution and damage modes of the specimens are investigated in relation to the temperature and the number of cold and hot treatments, and finally the damage mechanism of granite specimens after repeated high temperature-water cooling is discussed from microstructural changes. The test results show that with the increase of temperature and hot and cold treatment times, the brittleness of granite specimens after the peak decreases, the plasticity increases, the tensile strength, the average stiffness and the cracking load show an overall decreasing trend, and the location of crack budding shifts from the two ends of the specimen to the middle, the main crack transforms from linear to curved and wavy, and the opening of the main crack gradually increases, the number of secondary cracks gradually increases, and the fracture surface transforms from smooth to granular structure.
Wheat is the main grain crop in our country, and the traditional wheat yield estimation method is time-consuming and laborious. By estimating wheat yield efficiently, quickly and non-destructively, ...agricultural producers can quickly obtain information about wheat yield, manage wheat fields more scientifically and accurately, and ensure national food security. Taking the Xinxiang Experimental Base of the Crop Science Research Institute, Chinese Academy of Agricultural Sciences as an example, hyperspectral data for the critical growth stages of wheat were pre-processed. A total of 27 vegetation indices were calculated from the experimental plots. These indices were then subjected to correlation analysis with measured wheat yield. Vegetation indices with Pearson correlation coefficients greater than 0.5 were selected. Five methods, including multiple linear regression, stepwise regression, principal component regression, neural networks and random forests, were used to construct wheat yield estimation models. Among the methods used, multiple linear regression, stepwise regression and the models developed using principal component analysis showed a lower modelling accuracy and validation precision. However, the neural network and random forest methods both achieved a modelling accuracy R2 greater than 0.6, with validation accuracy R2 values of 0.729 and 0.946, respectively. In addition, the random forest method had a lower cross-validation RMSE value, with values of 869.8 kg/hm−2, indicating a higher model accuracy. In summary, the random forest method provided the optimal estimation for wheat yield, enabling the timely and accurate pre-harvest wheat yield prediction, which has significant value for precision agriculture management and decision making.
Studying urban heat islands holds significance for the sustainable development of cities. This comprehensive study analyzed the temporal characteristics of a Surface Urban Heat Island and Canopy ...Layer Heat Island by employing Moderate-Resolution Imaging Spectroradiometer image data spanning from 2003 to 2020 over Beijing, China. Leveraging the Gaussian capacity model, the geometrical characteristics of the Surface Urban Heat Island and Canopy Layer Heat Island, such as intensity, center, direction, and range, were examined among three different timescales of day, month, and year. Results indicate that the intensities of the Surface Urban Heat Island and Canopy Layer Heat Island tend to have bigger seasonal variations during winter nights and summer daytime. In addition, at night the centers of Surface Urban Heat Island and Canopy Layer Heat Island are mainly concentrated in the range of 116.3°~116.4° E in longitude and 39.90°~39.95° N in latitude, while during the daytime they are more scattered, mainly in the range of 116.2°~116.5° E in longitude and 39.7°~40.0° N in latitude. In the hot season, the center of the heat island moves east to north, while in the cold season it moves west to south. Monthly average ellipse areas of Surface Urban Heat Island and Canopy Layer Heat Island vary more during the day than that at night, the maximum daytime differences were 2662 km2 and 2293 km2, while the maximum nighttime differences were 484 km2 and 265 km2. Overall, the average area is increasing, with the heat island center moving eastward and deflecting towards the northeast-southwest direction. The expansion of urban areas will continue to influence the movement and extent of heat islands. The study offers insights to inform strategies for mitigating urban heat islands.
As an important part of the Bohai economic rim, the Laizhou Bay has been stressed by serious eco-environmental problems in recent years. In this study, the Shannon-Wiener index (
H
'), AZTI’s marine ...biotic index (AMBI) and the multivariate AMBI (M-AMBI) were used to assess the ecological quality status (EQS) of the Laizhou Bay according to macrobenthos data collected annually in August 2011-2014. The results showed that the overall benthic habitat quality in the Laizhou Bay was assessed as “Good”. However, 25% of the samples were classified as “Moderate”, “Bad” or “Poor” status under degraded conditions. Ecological group III (EGIII) species which had a certain tolerance to environmental disturbances had a higher proportion in each station, and most of them had appeared the pollution indicator species
Capitella capitata
. This indicated that the benthic habitat in the Laizhou Bay had been disturbed and polluted to some extent. The comparison of the three indices evaluation result and the RDA analysis showed that the
H
' and M-AMBI were more suitable when the relative abundance of the single species was high and the macrobenthic community was significantly imbalanced; when the relative abundance of opportunistic species (EGIV and EGV) was high, the AMBI and M-AMBI could reflected the EQS objectively; in an undisturbed and polluted environment, all the three indices could indicate the benthic habitats quality. In summary, the better correlation between the three indices and environmental factors showed that they were well responsive to the tendency of the benthic habitats quality in the Laizhou Bay.
Circularly polarized light (CPL) detection has emerged as a key technology for various optoelectronics. Chiral hybrid perovskites (CHPs) that combine CPL‐sensitive absorption induced by chiral ...organic ligands and superior photoelectric properties of perovskites are promising candidates for direct CPL detection. To date, most of the CHP detectors are made up of polycrystalline thin‐film, which results in a rather limited discrimination of CPL due to the existence of redundant impurities and intrinsic defect states originating from rapid crystallization process. Here, it is developed a direct CPL detector with high photocurrent and polarization selectivity based on low‐defect CHP single‐crystal nanowire arrays. Large‐scale CHP nanowires are obtained through a micropillar template‐assisted capillary‐bridge rise approach. Thanks to the high crystallinity and ordered crystallographic alignment of these arrays, a CPL photodetector with high light on/off ratio of 1.8 × 104, excellent responsivity of 1.4 A W−1, and an outstanding anisotropy factor of 0.24 for photocurrent has been achieved. These results would provide useful enlightenment for direct CPL detection in high‐performance chiral optoelectronics.
An efficient circularly polarized light (CPL) detector is demonstrated with large‐scale chiral hybrid perovskite (CHP) nanowire arrays. Based on the high photocurrent and polarization selectivity of CHP single‐crystals, high‐performance CPL detectors with high light on/off ratio and excellent polarization distinguishability through arranging such single‐crystalline CHP nanowires into low‐defect arrays are achieved.
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