摘要：
In order to investigate the dynamic response of embankment slopes supported by wooden frame beams and bamboo anchor rods under train loading, this study conducted model tests on embankment slopes supported by wooden frame beams and bamboo anchor rods and carried out three-dimensional numerical simulations of the slopes. This study focused on analyzing the effects of train loading frequency, the peak value difference, and the peak value of the soil pressure on the embankment slopes. This study also analyzed the horizontal displacement of the slope surface, the internal forces in the support structure, and the slope safety factor. The results indicated the following: (1) The increase in loading frequency from 2 Hz to 3 Hz resulted in a significant increase in dynamic soil pressure, with a smaller increase observed upon further frequency increments. Moreover, increasing the load or peak value difference led to an overall increase in the maximum dynamic soil pressure. (2) Under various loading conditions, the axial force in the top anchor rod was significantly greater than that in the middle anchor rod. Additionally, the axial force in the rod body exhibited a pattern of larger forces near the anchorage end and smaller forces near the anchor head. The location of the maximum bending moment in the anchor rod transitioned from the anchor head to the anchorage end as the slope depth increased. The bending moment of the anchor rod increased with the loading frequency but decreased with an increase in the peak value, showing a minor influence from the upper and lower peak values. (3) With the presence of this support system, the slope safety factor increased by 20.13%. A noticeable reduction in the horizontal displacement of the slope surface was observed, with the greatest reduction in the top slope area, followed by the slope angle.
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.
摘要：
Lightweight polymer composites promise incredible applications in aerospace, seaprobes, and medical apparatus. However, their performance is generally limited by a trade-off between mechanical strength and toughness. Herein, a crystallinity mitigating strategy driven by highly aligned bamboo macrofibers embedded in a polycaprolactone polyol (PCL) matrix for producing ultrastrong and tough lightweight polymer composites is proposed. The embedded bamboo macrofibers have oxygen-containing functional groups on the fiber surface, that can interact with functional groups (ester and hydroxyl groups) in the molecular chains of the PCL in the form of hydrogen bonds, thus preventing the aggregation of molecular chains and the crystallization of PCL, which ultimately leads to unprecedented toughness. Meanwhile, the bamboo macrofibres with intrinsically aligned microstructure, can enable effective stress transfer and dissipation, providing remarkable ultrahigh strength. As a result, the obtained lightweight polymer composite achieves ultrahigh mechanical strength (31.5 MPa) and superior toughness (21.7 MJ m-3) at an unprecedented low density (1.07 g cm-3), representing the state-of-the-art in reported lightweight polymers. Such lightweight polymer composite has the potential to greatly expedite the practical realization of artificial medical materials, including orthopedic instruments and joint prostheses. Herein, a crystallinity mitigation strategy driven by the embedding of highly aligned bamboo fibers into a polycaprolactone polyol (PCL) matrix is employed. At the same time, the bamboo fibers have an inherently aligned microstructure to effectively dissipate stress, and the resulting lightweight PCL composite achieves superior mechanical strength and excellent toughness at unmatched low density. image
摘要：
Reducing the ignition temperature of aromatic volatile organic compounds (VOCs) is a long-term pursuit for environmental pollution treatment and industrial application. In this paper, the toluene catalytic combustion was ignited at ultra-low temperature of 73 degrees C over a poplar wood monolithic catalyst with highly dispersed Pd particles coated by nano-thick graphited carbon layer via in-situ carbonization. Combing the characterizations and DFT calculations, the satisfying catalytic performance could be attributed to two aspects: (i) the unrestricted mass transfer of reactant and the high dispersity of Pd were simultaneously ensured in the straight micrometer-channel with abundant surface anchoring groups of poplar wood; (ii) the nano-thick graphited carbon layer on Pd significantly enhanced the oxygen activation. Given the low cost of economic wood and facile preparation technique, this work opened up new alternative for the preparation of highly dispersed noble metal catalyst and the low temperature catalytic combustion of aromatic VOCs in industry.
摘要：
The use of renewable materials as structural components for constructing superhydrophobic coatings is an important direction for future development. Here, a robust and photothermal superhydrophobic coating (with a water contact angle of 166.1 +/- 0.8 degrees and a sliding angle of 2.8 +/- 0.1 degrees) is fabricated using dual-size lignin micro-nanospheres (LMNSs), comprising lignin microspheres (m-LMNSs) and nanospheres (n-LMNSs), which successively settle on the substrate surface under the effect of gravity. The microstructure armor formed by the combination of m-LMNSs and epoxy resin endows the coating with excellent abrasion resistance and bonding strength. Moreover, the presence of n-LMNSs within the cavities provides water repellency. The coating maintains superhydrophobicity even after the abrasion distance exceeds 320 cm or after 210 tape peeling cycles. The coating also exhibits robustness under various forms of mechanical and chemical damage. Furthermore, the photothermal effect of the coating enables rapid heating of its surface temperature from similar to 13 to 112 degrees C in only 60 s under laser irradiation. This innovative structural regulation approach enhances the durability and photothermal performance of lignin-based superhydrophobic coatings, demonstrating the practical applicability of the approach.
通讯机构：
[Zhang, L ] C;Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Minist Educ, Changsha 410004, Hunan, Peoples R China.
关键词：
Mu oil tree;Flower development;Sexual dimorphism;Sex bias;Ethylene
摘要：
The mu oil tree (Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiation of mu oil tree via morphological and histological analyses of unisexual flowers: (I) differentiation of male or female primordia to produce staminate flowers (SFs) or transient hermaphrodite flowers (HFs), and (II) complete abortion of stamens in transient HFs to generate pistillate flowers (PFs). A total of 1621 sex-biased genes were identified by comparative transcriptome analysis which exhibited elevated rates of protein evolution than unbiased genes. The female-biased genes were enriched in the production of defense compounds while male-biased genes were focused on the production of viable pollens. Transcriptome-based analysis revealed that the differentially expressed genes (DEGs) between PFs and SFs in phase I involved in abscisic acid (ABA), auxin (AUX), cytokinin (CK), ethylene (ET), and gibberellin (GA) biosynthesis and signaling showed higher expression levels in males than in females in general, whereas the DEGs involved in jasmonic acid (JA) and salicylic acid (SA) pathways displayed opposite expression patterns. Moreover, differentially expressed endogenous ABA, AUX, GAs, JA, and SA exhibited consistent biased expression patterns with the DEGs by UPLC-MS-based analysis. Exogenous application of an anti-ethylene plant growth regulator could promote the development of stamens in PFs and generated HFs. Comparative transcriptomic and hormonal analyses of PFs and SFs in phase II indicated an increase in ET concentration when abortion of stamens in PFs occurred. This study suggested that phytohormones play key roles in sex dimorphism and ET may determine the development of stamens in PFs of mu oil tree, which provides an insight into plant sex differentiation mechanisms.
摘要：
Whitfordiodendron filipes var. tomentosum is an endemic plant in China. There have been no chemical or pharmacological studies of this plant reported before. In the current research, eight triterpenes and two steroids were obtained. Their structures were established by the analysis of NMR data and comparison with those reported in the literature. These ten structurally diverse compounds comprised five distinct carbon frameworks with different functionalities. The chemotaxonomic significance of these secondary metabolites was discussed, disclosing the common components between the variant W. filipes var. tomentosum and the species W. filipe. Evaluation of α-glucosidase inhibitory activities of these isolates disclosed that compounds 1, 2, 4, and 6 exhibited significant α-glucosidase inhibitory activities (IC(50) = 16.6-19.2 μM), which were close in value to the positive control acarbose (IC(50) = 11.5 μM). Moreover, the binding modes between the biologically active compounds 1, 2, 4, and 6 and the α-glucosidase protein were preliminarily studied using molecular docking. This study not only showed the chemical and biological profile of the plant W. filipes var. tomentosum but also revealed that these components could be developed as hypoglycemic lead compounds.
作者机构：
[Peng, Jiqing; Peng, JQ; Xue, Chao; Gao, Yu; Cao, Shoujin; Zhang, Yaoyi; Wen, Yuxing; Chen, Tingfeng; Sheng, Song] Cent South Univ Forestry & Technol, Coll Forestry, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.;[Peng, Jiqing; Peng, JQ; Sheng, Song] Hunan Agr Univ, Yuelushan Lab, Qiushi Bldg, Changsha 410128, Peoples R China.;[Peng, Jiqing; Peng, JQ; Sheng, Song] Belt & Rd Int Union Res Ctr Trop Arid Nonwood Fore, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.
通讯机构：
[Peng, JQ; Cao, SJ ] C;[Peng, JQ ] H;Cent South Univ Forestry & Technol, Coll Forestry, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.;Hunan Agr Univ, Yuelushan Lab, Qiushi Bldg, Changsha 410128, Peoples R China.;Belt & Rd Int Union Res Ctr Trop Arid Nonwood Fore, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.
关键词：
hormone;regulation of flowering;transcriptome;molecular mechanism
摘要：
Understanding the molecular mechanisms that regulate flower growth, development, and opening is of paramount importance, yet these processes remain less explored at the genetic level. Flower development in Hydrangea paniculata 'Vanilla Strawberry' is finely tuned through hormonal signals, yet the genetic underpinnings are not well defined. This study addresses the gap by examining the influence of gibberellic acid (GA3), salicylic acid (SA), and ethylene (ETH) on the flowering traits and underlying molecular responses. Treatment with 100 mg/L SA significantly improved chlorophyll content and bolstered the accumulation of soluble sugars and proteins, advancing the flowering onset by 6 days and lengthening the flowering period by 11 days. Concurrently, this treatment enhanced inflorescence dimensions, increasing length, width, and petal area by 22.76%, 26.74%, and 27.45%, respectively. Contrastingly, 100 mg/L GA3 expanded inflorescence size but postponed flowering initiation and decreased inflorescence count. Higher concentrations of SA and GA3, as well as any concentration of ETH, resulted in delayed flowering and inferior inflorescence attributes. A physiological analysis over 50 days revealed that these regulators variably affected sugar and protein levels and modified antioxidant enzyme activities. An RNA-seq analysis during floral development highlighted significant transcriptomic reprogramming, with SA treatment downregulating Myb transcription factors, implicating them in the modulation of flowering timing and stress adaptation. These findings illuminate the complex interplay between hormonal treatments, gene expression, and flowering phenotypes in Hydrangea paniculata, offering valuable perspectives for ornamental horticulture optimization.
摘要：
Firmiana danxiaensis (F. danxiaensis) is a special native species with a narrow distribution. More than 90 % of the plant species in the genus that F. danxiaensis belongs to are rare species with a narrow distribution. The main distribution area is Mount Danxia, a representative area of China Danxia where many endemic species of the Danxia landform have been bred. We carried out a gap analysis by overlapping the nature reserves with the potential habitat of F. danxiaensis. The results show that: (1) the potential habitat area of F. danxiaensis is 6,255.28 km(2) simulated by the Biomod2 ensemble model and 4,114.19 km(2) by Maxent, respectively, which accounted for 3.48 % and 2.29 % of the study area, located in Nanxiong county, Shixing county, Renhua county, and Qujiang county; (2) F. danxiaensis prefers areas with the max temperature of the warmest month over 32.5degree celsius, the temperature seasonality between 6000 and 7000, and the occurrence probability of F. danxiaensis was at its highest level when the max temperature of the warmest month reached between 36 and 37 degrees C, the temperature seasonality was nearly 7000; (3) more than 40 % of the potential habitat of F. danxiaensis was anthropogenically disturbed; (4) in the potential habitat simulated by Maxent, the conservation gap area is 3,390.26 km(2), accounting for 82.40 % of the total potential habitat, in the potential habitat simulated by Biomod2 ensemble model, the conservation gap area is 4.899.62 km(2), accounting for 78.33 % of the total potential habitat. The protection status of F. danxiensis is poor, with populations of F. danxiaensis in Yingde and Shixing not covered by nature reserves and already subject to serious human disturbance. It is recommended that the structure of existing protected areas be adjusted, the scope of corresponding nature reserves be appropriately expanded, and new nature reserves be added to ensure the sustainable development of F. danxiaensis populations.
作者机构：
[Li, Zhi; Zhu, Mingshan; Zhou, Daixi] Jinan Univ, Sch Environm, Guangdong Key Lab Environm Pollut & Hlth, Guangzhou 511443, Peoples R China.;[Hu, Xinjiang] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.;[Chen, Li] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 1, Dept Gen Practice, Beijing 100853, Peoples R China.
通讯机构：
[Chen, L ] C;[Zhu, MS ] J;Jinan Univ, Sch Environm, Guangdong Key Lab Environm Pollut & Hlth, Guangzhou 511443, Peoples R China.;Chinese Peoples Liberat Army Gen Hosp, Med Ctr 1, Dept Gen Practice, Beijing 100853, Peoples R China.
关键词：
advanced oxidation process;persulfate;reactive oxygen species;single atom catalysts;substance
摘要：
In this review, SACs with different metal species and substrates are summarized to investigate the metal−support interaction effects on the persulfate oxidation reaction for water treatments. Abstract With maximum utilization of active metal sites, more and more researchers have reported using single atom catalysts (SACs) to activate persulfate (PS) for organic pollutants removal. In SACs, single metal atoms (Fe, Co, Cu, Mn, etc.) and different substrates (porous carbon, biochar, graphene oxide, carbon nitride, MOF, MoS2, and others) are the basic structural. Metal single atoms, substances, and connected chemical bonds all have a great influence on the electronic structures that directly affect the activation process of PS and degradation efficiency to organic pollutants. However, there are few relevant reviews about the interaction between metal single atoms and substances during PS activation process. In this review, the SACs with different metal species and substrates are summarized to investigate the metal−support interaction and evaluate their effects on PS oxidation reaction process. Furthermore, how metal atoms and substrates affect the reactive species and degradation pathways are also discussed. Finally, the challenges and prospects of SACs in PS‐AOPs are proposed.
摘要：
Improving the adsorption performance of wetland fillers is of great significance for enhancing pollutant removal in constructed wetlands. Currently, limited by complex preparation processes and high costs, large numbers of high adsorption fillers studied in lab are difficult to be applied in practical engineering. In this study, a newly low-cost and efficient phosphorus removal composite wetland filler (CFB) is prepared by using industrial and agriculture waste (steel slag and oyster shells) and natural ore (volcanic rock) as raw materials. The results show that phosphorus removal efficiency was largely enhanced by synergistic effects of steel slag, oyster shells, and volcanic rock, and it was mainly influenced by the proportion of each component of CFB. Based on the fitting of the classical isothermal equation, the adsorption capacity of CFB is 18.339 mg/g. The adsorption of phosphorus by CFB is endothermic and spontaneous, and there are heterogeneous surfaces and multi-layer adsorption processes, as well as pH value and temperature, are free from the influence on CFB phosphorus removal. During the practical wastewater application experiments, the phosphorus removal rate of the CFB-filled constructed wetland apparatus (CW-A) can reach 94.89% and is free from the influence on the removal of other pollutants (COD, TN, and NH(3)-N) by the system. Overall, the prepared CFB is of excellent decontamination effect, an extremely simple preparation process, low cost, and sound practical engineering application potential, providing new ideas and approaches for enhancing the phosphorus removal capacity and waste resource utilization of constructed wetland systems.
期刊：
Science of The Total Environment,2024年922:171245 ISSN：0048-9697
通讯作者：
Hang Zhou
作者机构：
[Liao, Bohan; Zeng, Peng; Liao, Ye; Liu, Jiawei; Gu, Jiaofeng; Ni, Li; Zhou, Hang] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;[Zeng, Peng] Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China. Electronic address: zengzengpp@foxmail.com;[Zhou, Hang] Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China. Electronic address: zhouhang4607@163.com;[Wang, Yun] College of Life and Environmental Science, Hunan University of Arts and Science, Changde 415000, China;[Liao, Bohan; Gu, Jiaofeng] Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China
通讯机构：
[Hang Zhou] C;College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China
关键词：
Cd and As pollution soil;Compound passivator coupled with foliar spraying and soil applying Si fertilizer;Health risk evaluation;Rice
摘要：
Cadmium (Cd) and arsenic (As) are precedence-controlled contaminants in paddy soils, that can easily accumulate in rice grains. Limestone and sepiolite (LS) compound passivator can obviously reduce Cd uptake in rice, whereas Si fertilizer can effectively decrease rice As uptake. Here, the synergistic effects of the LS compound passivator coupled with Si fertilizer (LSCS) on the soil pH and availability of Si, Cd, and As, as well as rice grain Cd and As accumulation and its health risk were studied based on a 3-year consecutive field experiment. The results showed that the LSCS performed the best in terms of synchronously decreasing soil Cd and As availability and rice Cd and As uptake. In the LSCS treatments, soil pH gradually decreased with the rice-planting season, while soil available Cd and As contents gradually increased, suggesting that the influence of LSCS on Cd and As availability gradually weakened with rice cultivation. Nonetheless, the contents of Cd and inorganic As (i-As) in rice grains treated with LSCS were slightly affected by cultivation but were significantly lower than the single treatments of LS compound passivator or Si fertilizer. According to the Cd and As limit standards in food (GB2762-2022), the Cd and i-As content in rice grains can be lowered below the standard by using the 4500kg/hm(2) LS compound passivator coupled with 90kg/hm(2) Si fertilizer in soil and spraying 0.4g/L Si fertilizer on rice leaves for at least three years. Furthermore, health risk evaluation revealed that LSCS treatments significantly reduced the estimated daily intake, annual excess lifetime cancer risk, and hazard quotient of Cd and i-As in rice grains. These findings suggest that LSCS could be a viable approach for reducing Cd and As accumulation in rice grains and lowering the potential health risks associated with rice.
