摘要:
Enzymatic hydrolysis lignin residues (EHLRs) of lignocellulose usually adsorbs cellulase, which can be recycled and used to replace parts of cellulase in the hydrolysis process. To understand this phenomenon during enzymatic hydrolysis (EH) of sugarcane bagasse (SCB) treated with sulfite (SPORL) and dilute acid (DA), the adsorption characteristics between lignin and cellulase in EHLRs were investigated, focusing on interaction force at molecular level and enzymatic activity. The results revealed that SPORL-EHLR adsorbed more beta-glucosidases (beta-GLs) through the stronger electrostatic attraction and hydrogen bond force, causing higher cellulase adsorption amount compared to DA-EHLR. Further exploration demonstrated that the cellobiose's catalytic and binding sites on beta-GLs were separated from the binding site of SPORL-EHLR on beta-GLs, resulting in minimal in-hibition of beta-GLs activity when bound to SPORL-EHLR. Furthermore, adding SPORL-EHLR in SCB hydrolysis saved 40% cellulase. This study deepens the understanding of the adsorption behavior between lignin and cellulase.
期刊:
Forest Policy and Economics,2024年160:103146 ISSN:1389-9341
通讯作者:
Zhang, SH
作者机构:
[Zhang, Shouhong; Zhang, SH; Zhang, Fan; Ren, Yufei] Beijing Forestry Univ, Sch Soil & Water Conservat, Jixian Natl Forest Ecosyst Observat & Res Stn, CNERN, Beijing 100083, Peoples R China.;[Li, Mo] Northeast Agr Univ, Sch Water Conservancy & Civil Engn, Harbin 150030, Heilongjiang, Peoples R China.;[Zhang, Shouhong; Zhang, SH] Beijing Forestry Univ, State Key Lab Efficient Prod Forest Resources, Beijing 100083, Peoples R China.;[Liu, Jiakai] Beijing Forestry Univ, Sch Ecol & Nat Conservat, Beijing 100083, Peoples R China.;[Cao, Yini] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.
通讯机构:
[Zhang, SH ] B;Beijing Forestry Univ, Sch Soil & Water Conservat, Jixian Natl Forest Ecosyst Observat & Res Stn, CNERN, Beijing 100083, Peoples R China.;Beijing Forestry Univ, State Key Lab Efficient Prod Forest Resources, Beijing 100083, Peoples R China.
关键词:
National Reserve Forest Project of China;Afforestation project;Carbon neutrality;Carbon sink;Carbon cost and price
摘要:
The National Reserve Forest Project (NRFP) is a forestry project launched by China in 2013 to ensure the safety of timber supply and create a carbon sink, which can contribute to China's future carbon neutrality goals. To evaluate the carbon neutral contribution and carbon sink benefits of the NRFP, it is necessary to estimate the carbon sink amount, carbon sink cost, and carbon sink price. A combined method, modified Hartman model, and Rubinstein-Stahl bargaining model were used to estimate and analyze the carbon sink amount, carbon sink cost, and carbon sink price of NRFPs from several typical NRFP zones to the nationwide level. Results show that: (1) if the yearly construction area of the NRFP keeps stable at 10.2 × 105 ha in the future, the carbon sink of NRFP will account for about 17.32%, 28.35%, and 80.00% of total carbon emissions in 2060 under low-, middle-, and high-policy scenarios, respectively, representing an increase compared to the current level of approximately 16%; (2) the weighted average carbon sink cost of NRFP is estimated to be 95.16 CNY/t CO2 e (lower than the average carbon sink cost of 150 CNY/t CO2 e), and several measures such as applying Public-private partnership investment (PPP), increasing project operation duration, and choosing construction areas with low farmland benefit can help further reduce carbon sink cost of NRRP; (3) the reasonable carbon sink price should fall between the carbon sink cost and marginal carbon emission reduction cost of enterprises, and increasing the carbon sink price has a positive impact on NRFP construction. NRFPs suffer economic losses in the present carbon trade market, but they will gradually become profitable with the rising carbon sink price in the future. Therefore, it is imperative to maintain or gradually expand the construction area, provide more financial support, and improve the carbon trading market of NRFPs.
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.
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.
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.
摘要:
Helianthemum songaricum and H. ordosicum are two shrubs disjunctively distributed in Central Asia and northwestern China. For conservation purposes, we used genotyping by sequencing (GBS) to investigate the genetic diversity and genetic structure of their populations. Based on the GBS data, H. songaricum populations showed considerable genetic differences from H. ordosicum populations. Helianthemum songaricum populations also showed a stronger population genetic structure within the isolated valleys in the Tianshan Mountains than was seen in previous studies. We speculated that the two species may represent two cotemporal migration events between the Middle East and Central Asia/Ordos Plateau since the early Pliocene. Due to the intense uplift of the Tianshan Mountains in the late Pliocene, populations of H. songaricum were isolated in different valleys. Subsequently, the cold glacial climate during the Pleistocene intensified the in situ intraspecific differentiation of the species. Based on our single nucleotide polymorphism data, we propose habitat damage by anthropological activities, where the two species inhabit should be urgently prohibited by executive management. In addition, a nursery for germplasm resources should be urgently set up to culture adequate progenies for the purpose of expanding the populations.
作者机构:
[Yang, Lixue; Wang, Mingwei; Shan, Chengfeng; Yang, LX; Shen, Fangyuan] Northeast Forestry Univ, Sch Forestry, Natl Forestry & Grassland Adm, Engn & Technol Res Ctr Northeast Native Tree Speci, Harbin 150040, Peoples R China.;[Ji, Li; Ji, L] Cent South Univ Forestry & Technol, Sch Forestry, Changsha 410004, Peoples R China.;[Wang, Mingwei] Beijing Forestry Univ, Sch Forestry, Beijing 100083, Peoples R China.;[Yang, Yuchun] Jilin Prov Acad Forestry Sci, Changchun 130033, Peoples R China.
通讯机构:
[Ji, L ] C;[Yang, LX ] N;Northeast Forestry Univ, Sch Forestry, Natl Forestry & Grassland Adm, Engn & Technol Res Ctr Northeast Native Tree Speci, Harbin 150040, Peoples R China.;Cent South Univ Forestry & Technol, Sch Forestry, Changsha 410004, Peoples R China.
关键词:
Extracellular enzymes;Microbial metabolic limitation;Altitude;Soil depth;Stoichiometric ratio
摘要:
Mountain ecosystems have obvious variations in environmental factors at small spatial scales and thus provide a natural platform for investigating climate change. To investigate the characteristics of extracellular enzymes and microbial metabolic limitations in the hostile environmental conditions of cold temperate mountain ecosystems, soil physicochemical properties and enzyme activities were measured in the 0–10 cm and 10–20 cm soil layers of Larix gmelinii forests at elevations of 830 m, 950 m, 1100 m, and 1300 m. Our results showed that altitude and soil depth had a significant effect on 1,4-β-glucosidase, 1,4-β-N-acetyl-glucosaminidase, leucine aminopeptidase, and acid phosphatase activities. Extracellular enzyme activities decreased with increasing altitude and soil depth. The stoichiometric ratio of soil C-, N-, and P-acquiring enzymes after logarithmic transformation was 1:1.27:0.72 across all altitudes and soil depths. The metabolism of the microorganisms was mainly limited by C and N, and a high C limitation was observed at higher-altitude sites. With increased soil depth, the N limitation gradually weakened. Moreover, soil bulk density and pH were the main factors affecting extracellular enzyme activities and microbial nutrient constraints. Our study revealed that the carbon and nitrogen limitation of soil microbes was induced by the variation in soil factors in a cold temperate mountain forest ecosystem. This finding provides important insights into the mechanism of microbial metabolic limitation in the face of climate change.
通讯机构:
[Zhou, WR; Li, JZ ] B;[Li, C ] H;Beijing Forestry Univ, State Key Lab Efficient Prod Forest Resources, Beijing 100083, Peoples R China.;Beijing Forestry Univ, MOE Key Lab Wooden Mat Sci & Applicat, Beijing 100083, Peoples R China.;Beijing Forestry Univ, Beijing Key Lab Wood Sci & Engn, Beijing 100083, Peoples R China.
关键词:
epoxy polymeric siloxane nanoclusters;phenylboronicacid polymeric siloxane nanoclusters;hyperbranched;functional SM adhesive;toughness
摘要:
From an environmentally sustainable perspective, soybean meal (SM) adhesive presents an ideal alternative to petrochemical-based adhesives. Generally, strength and toughness are mutually exclusive for an adhesive. Hence, the creation of protein-based adhesives with high water-resistant strength of bonding, remarkable toughness, and multifunctionality remains a notable challenge. This study reports a dual hyperbranched siloxane nanocluster cross-linking strategy for creating SM-based adhesives with superior performance. In detail, synthesized hyperbranched epoxy siloxane nanocluster (ESN) and hyperbranched phenylboronic acid siloxane nanocluster (BPA@SN) were introduced into the SM matrix to establish a targeted cross-linking network between epoxy groups and protein chains as well as phenylboronic acid and polysaccharides. Meanwhile, the flexible Si-O segments within the hyperbranched siloxane facilitated energy dissipation, significantly boosting the adhesive toughness. After cross-linking modification, SM/ESN/BPA@SN-1 adhesive demonstrated outstanding dry bonding strength (2.04 +/- 0.18 MPa), water-resistant bonding strength (1.12 +/- 0.06 MPa), and toughness (18.5 +/- 4.02 kJ/m(3)). Moreover, the adhesive exhibited distinctly improved resistance to mold, thermal stability, and flame retardancy. Therefore, this new strategy of using functional hyperbranched siloxane nanoclusters and SM to design strong, tough, and multifunctional green and sustainable wood-based biomass adhesives provides new ideas for achieving green development.
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.
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.
摘要:
Enzymatic degradation of plastic is an effective means of plastic recycling and pollution control. However, the strong chemical inertness of polypropylene plastic (PP) severely impedes its oxidative cleavage, making it resistant to degradation. In this study, based on sequence screening of Hidden Markov Model (HMM), a dioxygenase (HIS1) was identified and characterized to be effective in PP oxidation. Various kinds of PP products, including plastic films, microplastics, and disposable water cups or bags, were HIS1-degraded with cracks and holes on the surface. The hydrophobic binding was the primary force driving oxidative degradation in the specific cavity of HIS1. The discovery of HIS1 achieved a zero breakthrough in PP biodegradation, providing a promising candidate for the selection and evolution of degrading enzymes.
关键词:
Chinese pangolin;CT;Histopathology;Immunohistochemistry;Infantile hemangioma
摘要:
Hemangiomas are a relatively common type of tumor in humans and animals. Various subtypes of hemangiomas have been described in the literature. The classification methods for hemangiomas differ between human and veterinary medicine, and the basis for tumor classification can be found in the literature. This study describes a tumor in the subcutaneous tissue of the right dorsum of an artificially rescued juvenile Chinese pangolin. Computed tomography (CT) examination yielded the preliminary diagnosis of a vascular malformation, and surgery was performed to resect the tumor. Histopathological examination showed that the tumor mainly was consisted of adipose tissue, capillaries, and spindle cells in the fibrous stroma. Immunohistochemistry showed the positive expression of CD31, CD34, α-SMA, GLUT1 and WT-1 in the tumor tissue, and the tumor was eventually diagnosed as an infantile haemangioma. The final diagnosis of infantile hemangioma was depended on the histopathological immunohistochemical and CT examination of the neoplastic tissue. This is the first report of infantile hemangioma in a critically endangered species Chinese pangolin.
期刊:
Journal of Environmental Management,2024年351:119688 ISSN:0301-4797
通讯作者:
Zhang, C;Yan, WD
作者机构:
[Ye, Zhencheng; Zhang, Chao; Wang, Wancai; Zhang, C; Li, Jing] Northwest A&F Univ, Key Lab Soil Eros & Dryland Farming Loess Plateau, Yangling 712100, Peoples R China.;[Liu, Guobin; Zhang, Chao] Chinese Acad Sci & Minist Water Resources, Inst Soil & Water Conservat, Yangling 712100, Peoples R China.;[Wang, Zhaoyang; Wu, Qixiao; He, Guoqin] Cent South Univ Forestry & Technol, Bangor Coll China Joint Unit Bangor Univ, Changsha 410004, Hunan, Peoples R China.;[Yan, Wende] Cent South Univ Forestry & Technol, Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.
通讯机构:
[Zhang, C ] N;[Yan, WD ] C;Northwest A&F Univ, Key Lab Soil Eros & Dryland Farming Loess Plateau, Yangling 712100, Peoples R China.;Cent South Univ Forestry & Technol, Natl Engn Lab Appl Technol Forestry & Ecol South C, Changsha 410004, Peoples R China.
关键词:
Abundant taxa;Agricultural ecosystem;Greenhouse gas emissions;Multinutrient cycling;Rare taxa
摘要:
The field practices, including irrigation and fertilization, strongly affect greenhouse gas emissions and soil nutrient cycling from agriculture. Understanding the underlying mechanism of greenhouse gas emissions, soil nutrient cycling, and their impact factors (fungal diversity, network characteristics, soil pH, salt, and moisture) is essential for efficiently managing global greenhouse gas mitigation and agricultural production. By considering abundant and rare taxa, we determine the identities and relative importance of ecological processes that modulate the fungal communities and identify whether they are crucial contributors to soil nutrient cycling and greenhouse gas emissions. The research is based on a 4-year field fertigation experiment with low (300kg/ha P(2)O(5) with 150kg/ha urea) and high (600kg/ha P(2)O(5) with 300kg/ha urea) fertilization level and three irrigation levels, that is, low (200mm), medium (300mm), and high (400mm). The α-diversity (richness and Shannon index) of fungal subcommunities was significantly higher under medium irrigation (300mm) and low fertilization (300kg/ha P(2)O(5) with 150kg/ha urea) than under other treatments. Intermediate irrigation with low fertilization treatment yielded the most significant higher multinutrient cycling index and the lowest CO(2) and CH(4) emissions. The null model indicated that abundant taxa are mainly regulated by stochastic processes (dispersal limitation), and rare taxa are mainly regulated by environmental selection, especially by soil salinity. The co-occurrence network of rare taxa explained the changes in the entire fungal network stability. The abundant taxa played vital roles in regulating soil nutrient status, owing to the stronger association between their network and multinutrient cycling index. Furthermore, we have confirmed that soil moisture and fungal network stability are crucial factors affecting greenhouse gas emissions. Together, these results provide a deep understanding of the mechanisms that reveal fungal community assembly and soil fungal-driven variations in nutrient status and network stability, link fungal network characteristics to ecosystem functions, and reveal the factors that influence greenhouse gas emissions.