摘要:
Forests are essential for maintaining species diversity, stabilizing local and global climate, and providing ecosystem services. Exploring the impact of paleogeographic events and climate change on the genetic structure and distribution dynamics of forest keystone species could help predict responses to future climate change. In this study, we combined an ensemble species distribution model (eSDM) and multilocus phylogeography to investigate the spatial genetic patterns and distribution change of Quercus glauca Thunb, a keystone of East Asian subtropical evergreen broad-leaved forest. A total of 781 samples were collected from 77 populations, largely covering the natural distribution of Q. glauca. The eSDM showed that the suitable habitat experienced a significant expansion after the last glacial maximum (LGM) but will recede in the future under a general climate warming scenario. The distribution centroid will migrate toward the northeast as the climate warms. Using nuclear SSR data, two distinct lineages split between east and west were detected. Within-group genetic differentiation was higher in the West than in the East. Based on the identified 58 haplotypes, no clear phylogeographic structure was found. Populations in the Nanling Mountains, Wuyi Mountains, and the southwest region were found to have high genetic diversity. A significant negative correlation between habitat stability and heterozygosity might be explained by the mixing of different lineages in the expansion region after LGM and/or hybridization between Q. glauca and closely related species. The Nanling Mountains may be important for organisms as a dispersal corridor in the west-east direction and as a refugium during the glacial period. This study provided new insights into spatial genetic patterns and distribution dynamics of Q. glauca.
摘要:
The distribution of species is mostly influenced by climate synergistic effects and land use. The prediction of endangered species is dependent on fine-scale environmental features, especially in forests. The capture of fine-scale suitable habitats is bounded by low spatial resolution and coarse categorization. In this study, we improved the land use information and forest spatial detail through high forest thematic resolution land use data. To understand the relative influence of environmental factors, suitable habitat models for Chinese endangered tree species (Firmiana danxiaensis) under three climate and high forest thematic resolution land use conditions was constructed. We also assess F. danxiaensis 's response to climate and land use, and differential performance in land use on the suitable habitat. The area of suitable habitat for F. danxiaensis grows slowly under the SSP1-2.6 (shared social pathway scenario) scenario, decreases by 21.33% from the present to 2090 under the SSP2-4.5 scenario, and expands significantly under the SSP5-8.5 scenario. We conclude that high forest thematic resolution land use is beneficial in capturing species' requirements for specific habitats and especially necessary in predicting endangered species. At the same time, the distribution of suitable habitats for species is primarily driven by climate, and limited their development by land use. The study shows that the synthetic effects of climate and land use change on F. danxiaensis are positive, with a marked trend toward the northeast. As a consequence, some endangered species are able to benefit from future SSPs scenarios, in particular they respond more strongly to the SSP5-8.5 scenario than to the other scenarios. Assessing the role of changes in the climate and high forest thematic resolution land use on F. danxiaensis will help promote sustainable land use management and contribute to the conservation policy for Chinese endangered species.
关键词:
Cadmium ion;Enrichment and removal;Fluorescent probe;Functionalized glass slide
摘要:
Cadmium (Cd) is a widespread and highly toxic environmental pollutant, seriously threatening animal and plant growth. Therefore, monitoring and employing robust tools to enrich and remove Cd from the environment is a major challenge. In this work, by conjugating a fluorescent indicator (CCP) with a functionalized glass slide, a special composite material (CCPB) was constructed to enrich, remove, and monitor Cd2+ in water rapidly. Then Cd2+ could be effectively eluted by immersing the Cd-enriched CCPB in an ethylenediaminetetraacetic acid (EDTA) solution. With this, the CCPB was continuously reused. Its recovery of Cd2+was above and below 100 % after multiple uses by flame atomic absorption spectrometry (FAAS), which was excellent for practical use in enriching and removing Cd2+ in real aqueous samples. Therefore, CCPB is an ideal material for monitoring, enriching, and removing Cd2+ in wastewater, providing a robust tool for future practical applications of Cd enrichment and removal in the environment.
摘要:
Exploring the single relationship between the inversion degree of spinel and its catalytic performance is a great challenge, but has important significance for further structural design and application. A series of CoMn inverse spinels were prepared and the general formula (Co-1-x(2+) Co-x(3+)) (tet) (Mn-1(3+) Co-x(2+) Co-1-x(3+))(oct)O-4 was deduced through X-ray diffraction refinement to find a decreased inversion degree x as calcination temperature rose. Catalytic oxidation of toluene showed that higher inversion degree (S-300 with x approximate to 0.95) can reach larger conversion rate (90 % at about 250 degrees C for 400 ppm toluene) with greater reaction stability (140 h). Density Functional Theory (DFT) calculations on density of states indicated its metallic nature, and found that the strength of O-p and Transition metal-d orbitals at Fermi energy is positively correlated to the inversion degree, meaning stronger electron migration ability. Along with the adsorption calculation analysis that lattice oxygen species are proved to work dominantly (S-300 with lowest adsorption energy but highest performance), this work uncovered a theoretical insight into inverse spinel oxide, to provide the possibility of elevated oxidation ability through structural control.
期刊:
IEEE Transactions on Intelligent Transportation Systems,2024年 ISSN:1524-9050
通讯作者:
Ji, B
作者机构:
[Ji, Bin; Ji, B; Zhou, Saiqi; Zhang, Dezhi] Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.;[Li, Shuangyan] Cent South Univ Forestry & Technol, Coll Logist & Transportat, Changsha 410004, Hunan, Peoples R China.
通讯机构:
[Ji, B ] C;Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.
关键词:
Two-echelon capacitated vehicle routing problem;sharing satellite resources;mixed integer linear programming model;adaptive large neighborhood search
摘要:
Collaboration vehicle routing has garnered increasing attention recently because it can help enterprises reduce costs by sharing resources. This paper addresses a novel two-echelon capacitated vehicle routing problem with sharing satellite resources (2E-CVRPSSR), which arises with the development of e-commerce and the Sharing economy in city logistics. In this problem, goods are delivered within a two-echelon routing network, where satellites are used to consolidate and transfer goods between first-and second-echelon routing. Moreover, the second-echelon vehicles can depart from and return to different satellites. A mixed integer linear programming model is first presented, and an adaptive large neighborhood search algorithm with several new search operators and strategies is proposed to solve this problem. The numerical results show that the proposed algorithm can effectively solve the 2E-CVRPSSR. Moreover, an average transportation cost savings of 6.29% can be obtained by sharing satellite resources. In addition, geographic analysis indicates that the layout of the depot, satellites, and customers largely impacts the economic advantages of sharing satellite resources. Specifically, the highest economic benefits are achieved when the satellites are distributed from nearest to farthest from the depot, with customers located between nearby and distant satellites and with satellites of large enough capacity close to the depot.
摘要:
Octacosanol, a naturally occurring higher fatty alcohol, possessed numerous biological effects. However, octacosanol limited solubility in water due to its lipophilic nature and large structure, resulting in poor absorption and low bioavailability. To overcome this challenge, we developed a simple, environmentally friendly, and energy-efficient O/W nanoemulsion synthesis process. The nanoemulsion achieved an average droplet size of approximately 30nm, exhibited excellent dispersibility and stability at room temperature for 60days, and showcased robust storage properties insensitive to ambient temperature, pH, NaCl, and sucrose. Remarkably, the preparation process of the nanoemulsion maintained the biological activity of octacosanol while demonstrating significantly enhancing antioxidant activity compared to octacosanol suspension. Additionally, the nanoemulsion displayed negligible cytotoxic effects on Caco-2 cells. Significantly, the octacosanol nanoemulsion exhibited a 5.4-fold enhancement in transmembrane transport efficiency when compared to the suspension in Caco-2 cell monolayers. Additionally, in an in vivo experiment, there was a notable 2.9-fold increase in rat intestinal absorption. These findings could provide valuable insights into the development of octacosanol nanoemulsion, supporting its future applications and paving the way for the design of stable nanoemulsion systems for other lipophilic and sparingly soluble substances.
摘要:
Cadmium-contaminated water and food are seriously hazardous to the human health, especially liver injury. To understand the entanglement relationship between cadmium ion (Cd2+)-induced liver injury and the biomarker sulfur dioxide (SO2), a reliable bioanalytical tool is urgently needed, detecting SO2 to diagnose and evaluate the extent of liver injury in vivo. Herein, based on the F & ouml;rster resonance energy transfer (FRET) mechanism, a novel SO2-tunable NIR ratiometric fluorescent probe (<bold>SMP)</bold> was developed, it was used to diagnose and treat liver injury induced by Cd2+ in biosystems. Specifically, it was constructed by conjugating a NIR dicyanoisophorone with a NIR benzopyranate as the donor and acceptor, respectively, and the ratiometric response of SO2- regulated by the Michael addition reaction. In addition, <bold>SMP</bold> exhibits rapid reaction time (<15 s), two well-resolved emission peaks (68 nm) with less cross-talk between channels for high imaging resolution, superior selectivity, and low limit of detection (LOD=80.3 nM) for SO2 detection. Impressively, <bold>SMP</bold> has been successfully used for intracellular ratiometric imaging of Cd2+-induced SO2 and diagnostic and therapeutic evaluation in liver injury mice models with satisfactory results. Therefore, <bold>SMP</bold> may provide a powerful molecular tool for revealing the occurrence and development relationship between SO2 and Cd2+-induced liver injury. Environmental Implication Cadmium ions are one of the well-known toxic environmental pollutants, which are enriched in the human body through inhalation of cadmium-contaminated air or from the food chain, leading to damage in various organs, especially liver injury. Therefore, we developed a novel fluorescent probe that can specifically detect SO2 in Cd2+-induced liver injury, which is critically important for the diagnosis and evaluation of Cd2+-induced liver injury diseases. The specific detection of SO2 of this probe has been successfully demonstrated in live HepG2 cells and Cd2+-induced liver injury mice.
通讯机构:
[Sun, DL ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
摘要:
Bamboo is an environmentally friendly building structural material. This work investigated the cavity structural characteristics and physical and mechanical properties of honeycomb sandwiches and natural bamboo in the longitudinal direction. The effective elastic parameters of periodically arranged hexagonal bamboo honeycomb cells under in-plane and out-of-plane loads were modeled using analytical and numerical approaches. Then, the effective elastic parameter model of bamboo honeycomb cells was validated by experiments and finite element analysis. The average errors between the calculated and experimental equivalent modulus of elasticity, Poisson's ratio, and shear modulus in the three principal axis directions were 7.43, 4.37, and 8.68%, respectively. The average relativities between the model values of the elastic parameters of the bamboo honeycomb cell and the simulation results in the three directions were 5.46, 5.40, and 6.12%, respectively. The experimental and finite element analysis showed that the constructed effective elastic parameter model of the bamboo honeycomb cell better reflected the state of the bamboo core when subjected to force. This study provides insights for further research on the mechanical properties of bamboo materials and their application in bamboo-based lightweight and high-strength sandwich structures.
期刊:
Computer-Aided Civil and Infrastructure Engineering,2024年39(4):617-634 ISSN:1093-9687
通讯作者:
Zhou, GX
作者机构:
[Yang, Yixin; Sun, Lixiang; Zhou, Guoxiong; Chen, Aibin; Zhang, Yukai] Cent South Univ Forestry & Technol, Coll Comp & Informat Engn, Changsha 410004, Peoples R China.;[Cai, Weiwei] Jiangnan Univ, Coll Artificial Intelligence & Comp Sci, Wuxi, Peoples R China.;[Li, Liujun] Univ Idaho, Dept Soil & Water Syst, Moscow, ID USA.
通讯机构:
[Zhou, GX ] C;Cent South Univ Forestry & Technol, Coll Comp & Informat Engn, Changsha 410004, Peoples R China.
摘要:
Abstract The segmentation accuracy of bridge crack images is influenced by high‐frequency light, complex scenes, and tiny cracks. Therefore, an integration–competition network (complex crack segmentation network [CCSNet]) is proposed to address these problems. First, a grayscale‐oriented adjustment algorithm is proposed to solve the high‐frequency light problem. Second, an integration–competition mechanism is proposed to detach complex backgrounds and grayscale features of cracks. Finally, a tiny attention mechanism is proposed to extract the shallow features of tiny cracks. CCSNet outperforms seven state‐of‐the‐art crack segmentation methods in both generalization and comparison experiments on self‐built dataset and four public datasets. It also achieved excellent performance in practical bridge crack tests. Therefore, CCSNet is an effective auxiliary method for lowering the cost of bridge safety detection.
作者机构:
[Gen-Hua Liu; Jin-Xiang Yan] College of Computer and Information Engineering, Central South University of Forestry and Technology, Changsha 410004, People's Republic of China
摘要:
The spin polarization of current plays an important role in the performance of spintronic devices. Therefore, a highly spin-polarized current source has always been explored through various methods. We study the effects of magnetic order on the electronic structures of antiferromagnetic (AFM) MnBi2Te4 films. A significant spin splitting is found in the surface states of a AFM MnBi2Te4 film with three septuple layers (SLs). The AFM film can show typical metallic behavior for spin-down electrons, and exhibit a semiconductor or insulator behavior with a band gap at the Fermi level for spin-up electrons, just like semimetal ferromagnets with theoretical spin polarization up to 100%. We also study that the electron transport in the 3-SLs AFM film with a square potential barrier, we find a highly spin-polarized current can be switched on and off by modulating the barrier height in the film.
摘要:
The "Annual Report 2021" from the United Nations Environment Programme (UNEP) highlights that the transportation sector is the fastest-growing greenhouse gas emissions sector, accounting for approximately 25% of energy-related emissions. What is even more concerning is that, at a time when carbon emissions need to be urgently reduced across various industries globally, carbon emissions from the transportation sector continue to rise. This is because the improvement in the efficiency of vehicle power combustion struggles to offset the increasing emissions resulting from the massive volume of travel. With the enhancement of transportation networks in various countries, it is projected that the growth rate of carbon emissions in the transportation sector will surpass that of the industrial and power sectors, presenting a significant challenge to achieving the emission reduction goals outlined in the Paris Agreement. Carbon emissions in the global transportation sector encompass various modes of transportation, including road, rail, aviation, and maritime, with road transportation being the largest contributor to carbon emissions. This study utilized the Stacking technique to build the X-MARL model for predicting
$$\hbox {CO}_{2}$$
emissions from vehicles and formulated recommendations for carbon reduction in the transportation industry. The model was tested using a dataset of vehicle
$$\hbox {CO}_{2}$$
emissions officially recorded by the Canadian government, comprising 7385 data points and covering 12 different vehicle parameter attributes. During the experimentation process, three statistical evaluation metrics were employed, namely mean squared error (MSE), root-mean-squared error (RMSE), and the coefficient of determination (R2). The dataset was randomly split into a training set (80% of the total data) and a testing set (20% of the total data). The experimental results demonstrated that the X-MARL model exhibited the highest prediction accuracy. This study provides an original strategy for accurately predicting carbon emissions from road transportation, which can offer support and guidance to decision-makers in formulating and implementing effective environmental policies.
摘要:
Sb-based materials exhibit considerable potential for sodium-ion storage owing to their high theoretical capacities. However, the bulk properties of Sb-based materials always result in poor cycling and rate performances. To overcome these issues, pyridine-regulated Sb@InSbS3 ultrafine nanoplates loaded on reduced graphene oxides (Sb@InSbS3@rGO) were designed and synthesized. During the synthesis process, pyridine was initially adopted to coordinate with In3+, and uniformly dispersed In2S3 ultrafine nanoplates on reduced graphene oxide were generated after sulfidation. Next, partial In3+ was exchanged with Sb3+, and Sb@InSbS3@rGO was obtained by using the subsequent annealing method. The unique structure of Sb@InSbS3@rGO effectively shortened the transfer path of sodium ions and electrons and provided a high pseudocapacitance. As the anode in sodium-ion batteries, the Sb@InSbS3@rGO electrode demonstrated a significantly higher reversible capacity, better stability (445 mAh<middle dot>g(-1) at 0.1 A<middle dot>g(-1) after 200 cycles and 212 mAh<middle dot>g(-1) at 2 A<middle dot>g(-1) after 1200 cycles), and superior rate (210 mAh<middle dot>g(-1) at 6.4 A<middle dot>g(-1)) than the electrode without pyridine (355 mAh<middle dot>g(-1) at 0.1 A<middle dot>g(-1) after 55 cycles and 109 mAh<middle dot>g(-1) at 2 A<middle dot>g(-1) after 770 cycles). Furthermore, full cells were assembled by using the Sb@InSbS3@rGO as anode and Na3V2(PO4)(3) as cathode, which demonstrated good cycling and rate performances and exhibited promising application prospects. These results indicate that adjusting the microstructure of electrode materials through coordination balance is A<middle dot>good strategy for obtaining high-capacity, high-rate, and long-cycle sodium storage performances.