作者机构:
[Zhong, Yijing; Zhai, Wenxiang; Wei, Xinli] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Zhai, Wenxiang] Northeast Forestry Univ, Key Lab Biobased Mat Sci & Technol, Minist Educ, Harbin 150040, Heilongjiang, Peoples R China.
通讯机构:
[Wei, XL ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词:
Cork;Sheets;Silica aerogel;Gaseous products;Char functional groups
摘要:
Recently, a novel lightweight cork with enhanced thermal stability has been prepared using a respiratory impregnation method. In this paper, the thermal stability and decomposition of two kinds of cork CS-P (Quercus suber) and CV-P (Quercus variabilis B1) and corks that infused silica aerogel in cells CSS-P (Quercus suber) and CSV-P (Quercus variabilis B1) were systematically studied, and their decomposition mechanisms were proposed. The results showed that the decomposition was inhibited at 200 degrees C, and the pyrolysis was significantly inhibited at the main pyrolysis stage (400 degrees C). Interestingly, the evolved gaseous products and their evolution models have also changed. Specifically, CO2 and aldehyde emissions were significantly reduced in the main pyrolysis stage, reducing environmental pollution. Silica aerogel filler plays a catalytic role in the pyrolysis process, thus increasing the output of some value-added products (such as aromatics), which is suitable as the appropriate raw material or source of olefins to produce aliphatic rich pyrolysis biofuels. In general, the yield of biochar and bio-oil can be adjusted under low environmental pollution by loading silica aerogel and adjusting pyrolysis tem-perature. Corks that infused silica aerogel in cells may be a promising raw material for the production of biochar and biofuel through pyrolysis and contribute to the environmental and economic sustainability of the cork production industry.
摘要:
As green renewable resources, wood and its composites are widely used in the construction field, which puts forward higher requirements for their flame-retardant performance. In this study, a high-temperature hydrothermal crystallization method for in situ constructing an epoxy crosslinked Si-Al zeolite-like structural wood composite (WZLC) was reported. Under the action of amine guiding agents and epoxy resin, the zeolite-like catalytic structure constructed in poplar wood comprised negative electrocatalytic sites, which can efficiently catalyze the formation of the carbon layer and endow WZLC with excellent flame retardant, smoke-suppression, and self-extinguishing properties. Compared with the untreated wood (WN), the thermal stability of the treated wood (WZLC) was greatly improved, and the amount of volatile organic compounds released during the decomposition process was significantly reduced. The heat release rate, total heat release, smoke production rate, and total smoke production of WZLC1 decreased by 50.23%, 44.14%, 45.21%, and 28.46%, respectively. Particularly, CO and CO2 yields of WZLC significantly decreased by 92.26% and 92.02%, respectively, indicating that the Si-Al zeolite-like catalytic structure displayed excellent catalytic flame retardant properties, which can effectively decrease the thermal decomposition rate and combustion risk of the WZLC. This method uses less flame retardants to achieve a good flame retardant and smoke suppression effect, thereby reducing the risk of environmental pollution caused by too many flame retardants.
摘要:
As a popular ornamental plant and an effective species for controlling rocky desertification, the identification and protection of potential habitats of Lagerstroemia excelsa habitats hold significant importance. To gain a comprehensive understanding of the natural resources and growing conditions for L. excelsa, predictive modeling was employed to estimate the potential geographical distribution of the species during the Mid-Holocene (MH), the present, and the years 2050 and 2070. The projection was based on current occurrences, and we selected the relevant environmental attributes through the Pearson analysis and the Maximum Entropy Model (MaxEnt). The analysis revealed that temperature and precipitation are the primary environmental factors influencing L. excelsa distribution, with the Wuling Mountains identified as a center distribution hub for this species. The anticipated suitable area for L. excelsa is expected to experience marginal expansion under future climate scenarios. These results are invaluable for guiding the protection and sustainable utilization of L. excelsa in the face of climate change. Additionally, the data generated can be leveraged for enhanced introduction, breeding, selection, and cultivation of L. excelsa, taking into account the challenges posed by global warming.
作者机构:
[Bai, Yu; Cao, Yongxiang; Zhang, Naichang; Ning, Chendong] Power China Northwest Engn Corp Ltd, Xian 710065, Peoples R China.;[Cao, Yongxiang] Shaanxi Union Res Ctr Univ & Enterprise River & La, Xian 710065, Peoples R China.;[Wang, Yushi] Beijing Forestry Univ, Beijing 100083, Peoples R China.;[Jia, Jianbo] Cent South Univ Forestry & Technol, Changsha 410004, Peoples R China.
通讯机构:
[Jia, JB ] C;Cent South Univ Forestry & Technol, Changsha 410004, Peoples R China.
关键词:
sap flow;rainfall types;K-means clustering;sub-humid climate
摘要:
Sap flow is one of the most important physiological water transport processes of trees, and the characteristics of sap flow are greatly affected by the spatial and temporal distribution of water in the SPAC (soil–plant–atmosphere continuum). However, different precipitation characteristics have great influence on the water environment of forest trees, which causes considerable differences in sap flow. Therefore, researching the response of sap flow to precipitation type is the key to accurately determining plant transpiration in semi-arid areas. We used K-means clustering analysis to divide the rainfall during the study period into three rainfall types (the highest rainfall amount and intensity (types I), medium rainfall amount and intensity, with a long duration (types II); and the lowest rainfall amount and intensity (types III)) based on the rainfall amount and intensity in order to compare the differences in the response of sap flow trends and influencing factors of Pinus tabulaeformis and Robinia pseudoacacia under different rainfall types. The results showed that, under the daily scale average sap flow of P. tabulaeformis and R. pseudoacacia, rainfall type II decreased significantly relatively to rainfall types I and III (p < 0.05). In rainfall type II, The sap flow characteristics of R. pseudoacacia were positively correlated with solar radiation (p < 0.05), while those of P. tabulaeformis were positively correlated with temperature, solar radiation, and VPD (p < 0.01). The sap flow of P. tabulaeformis and R. pseudoacacia were significantly positively correlated with temperature, solar radiation, VPD, and soil moisture content (p < 0.01) and negatively correlated with relative humidity (p < 0.05) in rainfall type III. The hourly sap flow of P. tabulaeformis and R. pseudoacacia on rainfall days was higher than before the rainfall. Rainfall type I promoted the daily sap flow of both species, and the proportion of the sap flow in daytime was also higher. On rainy days, the sap flow rates of rainfall type I and III showed a “midday depression”. In type I rainfall events, the sap flow “midday depression” after rainfall occurred an hour ahead compared to the sap flow “midday depression” before rainfall. In type II rainfall events, the daytime sap flow rates of P. tabulaeformis and R. pseudoacacia were obviously inhibited, but the nighttime sap flow rate increased. In type III rainfall events, the sap flow before rainfall presented a unimodal curve versus time. The daily average sap flow of R. pseudoacacia was more susceptible to rainfall type II, while P. tabulaeformis was more susceptible to rainfall types I and III. The sap flow rate of R. pseudoacacia decreased on rainy days. The results show that the effects of different rainfall types on the sap flow trends of P. tabulaeformis and R. pseudoacacia were different. They revealed the responses of their sap flow trends to meteorological factors under different rainfall types, which provided basic data and theoretical support for further predicting the sap flow trends on rainy days, clarifying the effects of rainfall amount, rainfall duration, and rainfall intensity on sap flow trends and accurately estimating the transpiration water consumption of typical tree species in the sub-humid climate regions of China.
关键词:
Heavy metal stress;Transcriptional activation;Gibberellin signal;Phytoremediation
摘要:
Heavy metal pollution has become increasingly prominent, and bioremediation of heavy metal polluted areas is urgently needed. Broussonetia papyrifera is a pioneer tree species for vegetation restoration in the tailings area, while its molecular mechanism of heavy metal adaptation is not clear. Here, we report that a R2R3 MYB from B. papyrifera (BpMYB1) is involved in Cd accumulation by controlling the down-stream genes and mineral accumulation. Overexpression of BpMYB1 in B. papyrifera resulted in a significant increase in Cd accumulation and multiple gene transcription. Among the up-regulated genes, BpMYB1 could bind to ferrochelatase (BpFC2), basic helix-loop-helix transcription factor bHLH93 (BpbHLH93), and basic leucine zipper transcription factor bZIPs (BpbZIP1, BpbZIP-CPC1) by recognizing TATCCAOSAMY (TATCCA) motif and related promoter segments. Further investigations revealed that overexpression of BpbZIP1 promotes the absorption of Cd, BpMYB1 regulate Cd uptake in plant relating to Fe accumulation without Fe-deficiency pathway via recognizing the downstream BpbHLH93 and involving in PCs biosynthetic pathway via recognizing the target BpFC2. Moreover, the Cd response effect mediated by BpMYB1 was boosted by interacting with a DELLA protein BpGAI1, a vital member of of GA signaling. These results provide new insights into the molecular feedback mechanisms underlying BpMYB1-BpGAI1 controlled Cd uptake in plants, which will benefit for phytoremediation of Cd polluted soil.
通讯机构:
[Zhou, B; Peng, D ] C;[Zhou, B ] N;Cent South Univ Forestry & Technol, Fac Life Sci & Biotechnol, Changsha 410004, Hunan, Peoples R China.;Huitong Natl Field Stn Sci Observat & Res Chinese, Huaihua 438107, Hunan, Peoples R China.;Natl Engn Lab Appl Technol Forestry & Ecol Souther, Changsha 410004, Hunan, Peoples R China.
关键词:
TARGET OF MONOPTEROS;environmental cues;genetic engineering;root development;transcription factor;vascular development
摘要:
Plants have an incredible ability to sustain root and vascular growth after initiation of the embryonic root and the specification of vascular tissue in early embryos. Microarray assays have revealed that a group of transcription factors, TARGET OF MONOPTEROS (TMO), are important for embryonic root initiation in Arabidopsis. Despite the discovery of their auxin responsiveness early on, their function and mode of action remained unknown for many years. The advent of genome editing has accelerated the study of TMO transcription factors, revealing novel functions for biological processes such as vascular development, root system architecture, and response to environmental cues. This review covers recent achievements in understanding the developmental function and the genetic mode of action of TMO transcription factors in Arabidopsis and other plant species. We highlight the transcriptional and post-transcriptional regulation of TMO transcription factors in relation to their function, mainly in Arabidopsis. Finally, we provide suggestions for further research and potential applications in plant genetic engineering. Target of monopteros (TMO) transcription factors are involved in vascular development, root formation, and response to environmental cues in plants. Transcriptional and post-transcriptional regulation of TMO transcription factors is critical to plant development.
期刊:
Case Studies in Construction Materials,2024年20:e02768 ISSN:2214-5095
通讯作者:
Zhan, XF
作者机构:
[Zhan, Xue-fang; Yan, Heng-li; Zhan, XF; Chen, Jing-yuan; Wang, Xian] Cent South Univ Forestry & Technol, Shaoshan South Rd 568, Changsha 410004, Peoples R China.
通讯机构:
[Zhan, XF ] C;Cent South Univ Forestry & Technol, Shaoshan South Rd 568, Changsha 410004, Peoples R China.
关键词:
Crumb rubber;R-ECC mixtures;R-ECC road -bridge link slab;Mix proportion;Sensitivity finite element analysis;Crack distribution
摘要:
This paper presents a different way using crumb rubber and fine sand totally replaced for silica sand within ECC mixtures to make rubberized engineered cementitious composites (R-ECC) to solve the issues of high construction cost of the road-bridge link slab for fully jointless bridges (FJBs). The crumb rubber with a size of 80 CR was replaced with fine sand from a volume rate of 5–20% in multiples of 5% to prepare the R-ECC material. Five different R-ECC mixtures (CR0-CR20) with different mix designs were prepared and tested, then an optimum mix proportion for the R-ECC mixtures was found. An R-ECC road-bridge link slab made of the optimum mix proportion which replace with fine sand in a volume rate of 15% was constructed, and its absorptive deformation capacity, tensile performance, and crack distribution under the most unfavourable load (temperature drop load) were studied. It is found that the R-ECC slab has good absorptive deformation capacity, crack control capacity and better internal force distribution. Therefore, R-ECC mixtures can be utilized for road-bridge link slab construction. Then, a sensitivity finite element comparative analysis was carried out considering the content of crumb rubbers, the friction coefficient and the slab length. It is found that the design length has a greater influence on the tensile performance of the R-ECC slab than other factors. Finally, a preliminary design theory of road-bridge link slab for FJBs has been established.
期刊:
Journal of Cleaner Production,2024年434:140106 ISSN:0959-6526
通讯作者:
Qin, CR;Li, ZH
作者机构:
[Qin, Chengrong; Huang, Haibo] Guangxi Univ, Sch Light Ind & Food Engn, Nanning 530004, Peoples R China.;[Li, Zhihan; Li, ZH; Qing, Yan] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Hu, Can] Hunan Univ Technol, Hunan Key Lab Biomass Fiber Funct Mat, Zhuzhou 412007, Peoples R China.
通讯机构:
[Li, ZH ] C;[Qin, CR ] G;Guangxi Univ, Sch Light Ind & Food Engn, Nanning 530004, Peoples R China.;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词:
Oily sludge;Amphipathic hemicellulose derivatives;Biosurfactants;Oil recovery;Kinetic model
摘要:
This study presents an improved sustainable approach to produce high-performance hemicellulose-based biosurfactants for environmentally friendly oily sludge remediation and oil components recovery. The amphipathic hemicellulose derivatives were prepared by hydrothermal extraction from renewable bamboo resources followed by rapid homogeneous esterification with alkenyl succinic anhydrides (C12–C18). The chemical structures of the prepared amphipathic hemicellulose derivatives were analyzed by FT-IR and NMR. The amphipathic hemicellulose derivatives with different hydrophobic chains were used to improve the separation and recovery of oil components from oily sludge in the thermal washing process. The hemicellulose modified with octadecenylsuccinic anhydride (HC-ODSA) exhibited the best oil recovery rate of 79.9%. The results of the interfacial activity, foaming, emulsification, and solubilization tests confirmed that the carbon chain length in the introduced hydrophobic groups exerted a substantial influence on the surface-active characteristics of the prepared amphipathic hemicellulose derivatives. Moreover, the results of desorption kinetics revealed that the amphiphilic hemicellulose molecules can reduce the interfacial tension between oil and water by adsorption at the interface and the petroleum hydrocarbons follow the pseudo-second-order desorption kinetic mode.
摘要:
Diabetes is one of the most prevalent diseases worldwide. The tissue regeneration of diabetes patients is known to be rather tricky as the result of vascular dysfunction, and this leads to various clinical complications including diabetic foot ulcers. The vascular endothelial cells, which compactly line the inner surface of blood vessels, are responsible for the growth and maintenance of blood vessels and play an essential role in tissue regeneration. Although the mechanical properties of cells are generally known to be regulated by physiological/pathological conditions, few studies have been performed to investigate vascular endothelial cellular mechanics under hyperglycemia and the biological functions related to tissue regeneration. In this study, we conduct a systematic investigation of this issue. The results suggested that the stiffness of human umbilical vein endothelial cells (HUVECs) can be significantly regulated by the glucose concentration, subsequently, leading to significant alterations in cell migration and proliferation capabilities that are closely related to tissue regeneration. The rearrangement of the cytoskeleton induced by hyperglycemia through Cdc42 was found to be one of the pathways for the alteration of the cell stiffness and the subsequent cell dysfunctions. Therefore, we suggested that the inhibition of Cdc42 might be a promising strategy to facilitate various tissue regeneration for diabetes patients.
摘要:
Light is one of the most important environmental factors for plant growth. In the production process of tung oil tree cultivation, due to the inappropriate growth of shading conditions, the lower branches are often dry and dead, which seriously affects the yield of tung oil trees. However, little is known about the key factors of light-induced tree photomorphogenesis. In this study, a total of 22 VfBBX family members were identified to provide a reference for candidate genes in tung tree seedlings. All members of the VfBBX family have different numbers of highly conserved B-box domains or CCT domains. Phylogenetic evolution clustered the VfBBX genes into four categories, and the highest density of members was on chromosome 6. Interspecific collinearity analysis suggested that there were six pairs of duplicate genes in VfBBX members, but the expression levels of all family members in different growth and development stages of the tung tree were significantly divergent. After different degrees of shading treatment and physiological data determination of tung tree seedlings, the differential expression level and chlorophyll synthesis genes correlation analysis revealed that VfBBX9 was a typical candidate nuclear localization transcription factor that was significantly differentially expressed in light response. This study systematically identified the VfBBX gene family and provided a reference for studying its molecular function, enhanced the theoretical basis for tung tree breeding, and identified excellent varieties.
摘要:
Metal-based materials are widely regarded as promising catalysts for activating peroxymonosulfate (PMS) to remove refractory organic contaminants with high efficiency. In our study, Ni-Fe layered double hydroxide (LDH)-biochar (BC) composite-induced PMS-based advanced oxidation process (AOP) was utilized to elucidate the degradation of tetracycline hydrochloride (TCH). In Ni-Fe LDH-BC/PMS system, more than 99% TCH (45 mu M) could be removed effectively at low doses of oxidant (PMS, 0.10 mM) and catalyst (Ni-Fe LDH-BC, 0.10 g/L) addition within 80 min. Besides, the Ni-Fe LDH-BC/PMS system showed high resistance to some inorganic anions, and the Ni-Fe LDH-BC composite possessed excellent reusability in the degradation of TCH (>99% in four cyclic experiments). The reaction mechanisms were investigated via electron paramagnetic resonance detection, chemical quenching tests, probe experiments, and electrochemical measurements. These results indicated that the electron-shuttle mechanism played the dominant role in the removal of TCH. It is worth noting that determination of PMS concentration can reflect the reliability of quenching experiments. In the Ni-Fe LDH-BC composite, BC could not only improve the dispersion of Ni-Fe LDH, but also increase the conductivity of Ni-Fe LDH. Overall, a successful modification strategy was proposed in our study to improve the catalytic property of Ni-Fe LDH, and reaction mechanisms of TCH degradation were discussed deeply and comprehensively.
摘要:
Single-atom catalysts have wide application prospects in peroxydisulfate (PDS)-based advanced oxidation process to degrade organic pollutants, but its catalytic performance is limited due to its cost, Metal-N coordination number, and single-atom loading amount. Herein, a novel nitrogen doped algal-based carbon confined singleatom copper catalyst (Cu-N/C-SAC((S))) was synthesized using molten salt assisted pyrolysis and coupling with PDS to degrade tetracycline (TC). AC-HAADF-STEM and XAFS analysis proved that single atom Cu was loaded (Content 1.9 %) successfully and coordinated with two N and two C. XPS and XANES spectra analysis suggested that Cu atoms mainly existed in a positive divalent state in Cu-N/C-SAC(S). When the catalyst dosage of Cu-N/CSAC((S)) was 0.1 g/L, TC was almost completely removed. Moreover, Cu-N/C-SAC(S) had a broad pH adaptation range and strong ability against interference. Singlet oxygen (O-1(2)), superoxide radicals (center dot O-2(-)), and electron transfer had an important contribution for TC removal. DFT calculations confirmed that the activation process of Cu-N/C-SAC((S)) producing SO4 center dot- was easier than the nitrogen doped blue-green algal-based carbon (N-BGAC). In addition, Cu-N/C-SAC((S)) possessed good recyclability and stability. The main degradation pathways of TC were analyzed, and the toxicity of the intermediates was calculated. This study provides a new solution strategy for the resource utilization of waste biomass, and provides technical support and theoretical guidance for the efficient application of single-atom catalysts in organic wastewater.
摘要:
It is important to reduce Cd and As content in brown rice in contaminated paddy soils. We conducted research on the effects of rice husk ash (RHA) on the Cd and As in the rhizosphere microenvironment (soil, porewater, and iron plaque) and measured the Cd, As, and Si content in rice plants. The main elements in RHA were Si (29.64%) and O (69.17%), which had the maximum adsorption capacity for Cd was 42.49 mg/kg and for As was 18.62 mg/kg. Soil pH and available Si content increased, while soil available Cd and As decreased following application of 0.5%-2% RHA. RHA promote the transformation of Cd to insoluble fraction, while As was transformed from a poorly soluble form to a more active one. RHA reduced Cd content and increased Si content in porewater, and reduced As only at the later rice growth stages. RHA increased the amount of iron plaque, thereby decreasing the Cd content in iron plaque, while increased the As content in it. Cd and inorganic As content in brown rice were decreased, to 0.31 mg/kg and 0.18 mg/kg, respectively. The decrease of Cd in brown rice was due to the decrease of Cd mobility in soil, thereby reducing root accumulation, while the decrease of As in brown rice was affected by the transport from roots to stems. Therefore, RHA can be considered as a safe and efficient in-situ remediation amendment for Cd and As co-contaminated paddy soil.(c) 2023 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
期刊:
Science of The Total Environment,2024年906:167219 ISSN:0048-9697
通讯作者:
Wang, Ping;Zhu, J
作者机构:
[Zhou, Tao; Sun, Jikang; Xing, Qinqin] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, 498 South Shaoshan Rd, Changsha 410004, Hunan, Peoples R China.;[Wang, Ping; Zhu, Jian; Zhu, J] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.;[Liu, Zhiming] Eastern New Mexico Univ, Dept Biol, Portales, NM 88130 USA.
通讯机构:
[Wang, P; Zhu, J ] C;Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.
关键词:
Cd stress;Koelreuteria paniculata;KpMIPS;Resistance
摘要:
Cadmium (Cd) pollution in soil is an important factor endangering plant growth and harming human health through food chains. Koelreuteria paniculata is an important woody plant for ecological restoration of Cd-contaminated soils. In this study, KpMIPS gene of K. paniculata was cloned, and the expressed protein (60kDa) had 1-phosphate synthase activity. The results showed that KpMIPS significantly promoted root development of K. paniculata and Arabidopsis thaliana, reduced damage to the roots of Arabidopsis thaliana caused by Cd, and decreased transfer of Cd to the aboveground parts of K. paniculata and Arabidopsis thaliana . In the K. paniculata plants overexpressing KpMIPS integrity of the root cells was maintained and the content of pectin and phytic acid was significantly increased. Overexpression of KpMIPS increased the Cd accumulation in the roots and decreased the Cd content in the stems and leaves. Clearly, KpMIPS could regulate the contents of pectin and phytic acid in K. paniculata, thereby passivating Cd(2+) and enriching it in the root cell wall, reducing the transfer of free Cd(2+) to other parts of K. paniculata, and providing a positive regulatory effect on the Cd resistance of K. paniculata. The results of the study provide a technical introduction for the selection and genetic improvement of target genes regulating heavy metal resistance of plants in phytoremediation technology.
摘要:
Thus far, the available works on sequencing flexibility in shop floor scheduling only consider the sequencing flexibility with serial operation constraint. However, the sequencing flexibility with discrete and hybrid operation constraints are also widely existed in the actual production and have significant impact on production efficiency. Therefore, this work proposes a distributed flexible job shop scheduling problem considering integrated sequencing flexibility (DFJSPS), in which the serial, discrete and hybrid operation constraints are considered simultaneously. A mixed integer linear programming model is proposed to solve the DFJSPS by using the CPLEX solver. Then, an efficient memetic algorithm (EMA) is designed with the objectives of minimizing makespan and total energy consumption. In the EMA, a five-layer coding method and an efficient initialization method are presented to obtain high quality initial solutions; and an efficient local search operator is designed to help the algorithm to improve its convergence speed. Comprehensive experiments show that the EMA outperforms other three well-known algorithms in most of the instances, demonstrating the superior performance of EMA for solving DFJSPS in terms of both computational efficiency and solution quality. In summary, the research fills the research gap on integrated sequencing flexibility in the field of shop floor scheduling; on the other hand, it can help production managers to obtain the efficient scheduling schemas in the decision-making systems about various types of sequencing flexibility.
摘要:
Solid-state LiDARs have become an important perceptual device for simultaneous localization and mapping (SLAM) due to its low-cost and high-reliability compared to mechanical LiDARs. Nevertheless, existing solid-state LiDARs-based SLAM methods face challenges, including drift and mapping inconsistency, when operating in dynamic environments over extended periods and long distances. To this end, this paper proposes a robust, high-precision, real-time LiDAR-inertial SLAM method for solid-state LiDARs. At the front-end, the raw point cloud is segmented to filter dynamic points in preprocessing process. Subsequently, features are extracted using a combination of Principal Component Analysis (PCA) and Mean Clustering to reduce redundant points and improve data processing efficiency. At the back-end, a hierarchical fusion method is proposed to improve the accuracy of the system by fusing the feature information to iteratively optimize the LiDAR frames, and then adaptively selecting the LiDAR keyframes to be fused with the IMU. The proposed method is extensively evaluated using a Livox Avia solid-state LiDAR collecting datasets on two different platforms. In experiments, the end-to-end error is reduced by 35% and the single-frame operational efficiency is improved by 12% compared to LiLi-OM.
作者机构:
[Ai, Wei; Meng, Tao; Meng, T; Xu, Jia; Shao, Hongen] Cent South Univ Forestry & Technol, Sch Comp & Informat Engn, Changsha 410082, Hunan, Peoples R China.;[Li, Keqin] State Univ New York New Paltz, Dept Comp Sci, New York, NY 12561 USA.
通讯机构:
[Meng, T ] C;Cent South Univ Forestry & Technol, Sch Comp & Informat Engn, Changsha 410082, Hunan, Peoples R China.
摘要:
Entity event deduplication is the task of identifying all duplication entity events that have described the same entity within a set of events. However, the traditional entity event deduplication method has two challenges. First, the traditional method usually used global comparison when finding the duplication entity event, are all entity events in the dataset need to be compared, leading to low performance. Second, when the entity event evolves, the traditional method does not identify it well and reduces the effectiveness. To address these two problems and improve the performance and effectiveness, we propose a two-stage deduplication method based on graph node selection and optimization (TS-NSNO) strategy. In the first stage (TS-NS), we propose a graph node selection strategy, which transforms the global comparison into a local comparison by selecting the leader node, greatly reduces the number of calculations and improves the performance. In the second stage (TS-NO), we propose a graph node optimization strategy, by combining the spatiotemporal distance and entity event importance change of the event evolution, which optimizes the entity event with incorrect judgment to improve the effectiveness. We conduct extensive experiments on real entity event datasets of different sizes, and the results show that our method performs better in terms of performance and effectiveness.
摘要:
The ultrasensitive detection of hepatitis C virus (HCV) nucleic acid is crucial for the early diagnosis of hepatitis C. In this study, by combining Ag@Au core/shell nanoparticle (Ag@AuNP)-based surface-enhanced Raman scattering (SERS) tag with hybridization chain reaction (HCR), a novel SERS-sensing method was developed for the ultrasensitive detection of HCV nucleic acid. This SERS-sensing system comprised two different SERS tags, which were constructed by modifying Ag@AuNP with a Raman reporter molecule of 4-ethynylbezaldehyde, two different hairpin-structured HCR sequences (H1 or H2), and a detection plate prepared by immobilizinga capture DNA sequence onto the Ag@AuNP layer surface of the detection wells. When thetarget nucleic acid was present, the two SERS tags were captured on the surface of the Ag@AuNP-coated detection well to generate many "hot spots" through HCR, forming a strong SERS signal and realizing the ultrasensitive detection of thetarget HCV nucleic acid. The limit of detection of the SERS-sensing method for HCV nucleic acid was 0.47 fM, and the linear range was from 1 to 10(5) fM.
摘要:
Our results highlight the regulatory role of the negative bacterial‐fungal association in enhancing the correlation between bacterial diversity and C mineralisation. This suggests that promoting short‐term successive planting in the management of Eucalyptus plantations can mitigate the impact of this association on SOC decomposition. Taken together, our study advances the understanding of bacterial‐fungal negative associations to mediate carbon mineralisation in Eucalyptus plantations, giving us a new insight into SOC cycling dynamics in artificial forests. Abstract Bacteria and fungi are core microorganisms in diverse ecosystems, and their cross‐kingdom interactions are considered key determinants of microbiome structure and ecosystem functioning. However, how bacterial‐fungal interactions mediate soil organic carbon (SOC) dynamics remains largely unexplored in the context of artificial forest ecosystems. Here, we characterised soil bacterial and fungal communities in four successive planting of Eucalyptus and compared them to a neighbouring evergreen broadleaf forest. Carbon (C) mineralisation combined with five C‐degrading enzymatic activities was investigated to determine the effects of successive planting of Eucalyptus on SOC dynamics. Our results indicated that successive planting of Eucalyptus significantly altered the diversity and structure of soil bacterial and fungal communities and increased the negative bacterial‐fungal associations. The bacterial diversity significantly decreased in all Eucalyptus plantations compared to the evergreen forest, while the fungal diversity showed the opposite trend. The ratio of negative bacterial‐fungal associations increased with successive planting of Eucalyptus due to the decrease in SOC, ammonia nitrogen (NH4+‐N), nitrate nitrogen (NO3−‐N) and available phosphorus (AP). Structural equation modelling indicated that the potential cross‐kingdom competition, based on the ratio of negative bacterial‐fungal correlations, was significantly negatively associated with the diversity of total bacteria and keystone bacteria, thereby increasing C‐degrading enzymatic activities and C mineralisation. Synthesis and applications: Our results highlight the regulatory role of the negative bacterial‐fungal association in enhancing the correlation between bacterial diversity and C mineralisation. This suggests that promoting short‐term successive planting in the management of Eucalyptus plantations can mitigate the impact of this association on SOC decomposition. Taken together, our study advances the understanding of bacterial‐fungal negative associations to mediate carbon mineralisation in Eucalyptus plantations, giving us a new insight into SOC cycling dynamics in artificial forests.
通讯机构:
[Liu, SG ] C;Cent South Univ Forestry & Technol, Changsha 410004, Peoples R China.
关键词:
Chinese fir plantations;Ecological network;Ecological stoichiometry;Enzyme stoichiometry;Forest restoration;Nutrient limitation;Soil biota
摘要:
Forest ecosystem productivity and function is strongly influenced by the interaction between soil organisms and their resource use that can be impeded by an imbalance of ecological stoichiometry. Soil microorganisms are known to have an important role in biogeochemical cycling which is strongly influenced by ecological stoichiometry. However, there is limited understanding of how soil micro-food web respond to stoichiometric imbalances during forest restoration. Here, we investigated the effect of forest restoration on soil physio-chemical properties and the structure and function of soil micro-food web along a chronosequence of transformation stages: (i) early stage monoculture plantation of Chinese fir (Cunninghamia lanceolata) comprised of three age classes (5, 10 and 20years); (ii) mid-stage conifer-broadleaved mixed forest; and (iii) late-stage mixed species broadleaved forest in south China. Results showed that forest restoration from C. lanceolata monocultures to mixed species broadleaved forest significantly increased soil organic carbon and total nitrogen. Soil bacteria, fungi, protists and nematodes abundance increased and the co-occurrence networks of soil biota became more complex and stable along the restoration chronosequence. In contrast, soil nitrogen and phosphorus limitations, particularly phosphorus limitation, increased along the chronosequence. In addition, soil exoenzyme activity suggested that the microbial investment in resource acquisition shifted from C- to nutrient-acquiring enzymes from the earlier to the later restoration stages. Availability of soil resources (e.g., dissolved organic carbon, ammonium, and available phosphate) appeared to have an important role in regulating soil food web composition, structure and stability during forest restoration. We conclude that nutrient limitation, particularly phosphorus limitation, likely has an important role in determining the stability of soil food webs during forest restoration. These findings contribute to our understanding of the relationships between soil nutrient limitation and soil micro-food web, and have implications for carbon sequestration through forest restoration and management in southern China.