作者机构:
[Sizhe Liu; Xiaofei Liu; Sijiao Li; Wenxing Xu] School of Civil Engineering, Central South University of Forestry & Technology, Changsha 410004, China;Author to whom correspondence should be addressed.;[Jian Yin] School of Civil Engineering, Central South University of Forestry & Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
通讯机构:
[Jian Yin] S;School of Civil Engineering, Central South University of Forestry & Technology, Changsha 410004, China<&wdkj&>Author to whom correspondence should be addressed.
摘要:
Ecological porous concrete (EPC) is one of the novel formulations of concrete with unique phytogenic properties. However, achieving both low alkalinity and high strength in EPC proves challenging due to the inherently high alkalinity of the pore environment, which hinders the growth of the plant and affects its ecological benefits significantly. This research investigated the utilization of 15 types of chemical admixtures and diatomaceous earth as alkali-reducing agents to optimize the properties of silicate cementitious materials for the applications of EPC. To identify the most effective agents, the pH value and compressive strength of the cement paste were adopted as the screening criteria for the selection of the essential alkali-reducing ingredients. Subsequently, a composite approach combining chemical admixtures and DE was employed to explore the synergistic effects on the pH and strength of silicate cementitious materials. The results revealed that a combination of 8% DE, 5% oxalic acid, and 5% iron sulfate functioned effectively and resulted in desirable performance for the concrete. This synergistic blend effectively consumed a large amount of Ca(OH)2, reducing the pH of cement paste to 10.48 within 3 days. Furthermore, the hydration reaction generated C-S-H with a low Ca/Si ratio, leading to a remarkable increase in the compressive strength of the concrete, reaching 89.7 MPa after 56 days. This composite approach ensured both low alkalinity and high strength in silicate cementitious materials, providing a theoretical basis for the application and promotion of EPC in the ecological field.
作者:
Yuan, Jianzhong;Wan, Caichao;Wei, Song;Chai, Huayun;Tao, Tao
期刊:
CURRENT ORGANIC SYNTHESIS,2024年 ISSN:1570-1794
作者机构:
[Wei, Song; Yuan, Jianzhong; Tao, Tao; Wan, Caichao; Chai, Huayun] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, P. R. China;[Wan, Caichao] Yihua Lifestyle Technology Co., Ltd, Huaidong Industrial Zone, Lianxia Town, Chenghai District, Shantou 515834, P.R. China
摘要:
BACKGROUND: Nanocellulose is not only a biocompatible and environmentally friendly material but also has excellent mechanical properties, biodegradability, and a large number of hydroxyl groups that have a strong affinity for water. These characteristics have attracted significant attention from researchers in the field of glucose sensing. OBJECTIVE: This review provides a brief overview of the current research status of traditional materials used in glucose sensors. The sensing performance, chemical stability, and environ-mental properties of nanocellulose-based glucose sensors are compared and summarized based on the three sensing methods: electrochemical sensing, colorimetric sensing, and fluo-rescence sensing. The article focuses on recent strategies for glucose sensing using nanocel-lulose as a matrix. The development prospects of nanocellulose-based glucose sensors are also discussed. CONCLUSION: Nanocellulose has outstanding structural characteristics that contribute signifi-cantly to the sensing performance of glucose sensors in different detection modes. However, the preparation process for high-quality nanocellulose is complicated and has a low yield. Furthermore, the sensitivity and selectivity of nanocellulose-based glucose sensors require further improvement.
摘要:
With the rapid growth of Internet data, recommendation systems have become the basic technology to alleviate information overload. The session-based recommendation (SBR) is a challenging task, and its purpose is to predict user behavior based on anonymous sessions. The existing SBR methods need to be improved in capturing the complex conversion relationship of items. In contrast, Graph Neural Network (GNN) can capture the complex conversion between items by modeling sessions as graph structure data. However, current methods just sort the clicked items within a session based on time, without utilizing the temporal information between sessions, leading to poor recommendation performance. To improve the accuracy of session recommendation (SR), we propose an SBR model based on GNN with Combined Temporal (CT-GNN) information. The proposed CT-GNN model is built based on the time of session occurrence, and it can learn the temporal association relationship between session items to enrich the connection between items. More importantly, based on the diversity problem faced by current SRs, which refers to the tendency of users to engage with popular items and resulting in limited exposure for other items, the CT-GNN model uses the Local Item Representation Learning (LIRL) module to learn users' local preferences. Through the LIRL module, the CT-GNN can capture users' interests, boost item exposure, and increase recommendation diversity. The experimental results show that the CT-GNN model is superior to the state-of-the-art SBR methods, with MRR scores 1.1 %∼3.4 % higher than the best-performing baseline; recall scores 0.9 %∼2.3 % higher than the best-performing baseline, and alleviates the diversity problem faced by SR, greatly improving the speed of model convergence, and the training time is 13.6 %∼20.7 % of the best-performing baseline.
摘要:
The function of the pith ring and cortex in biological and fluid exchanges with the surrounding environment implies a natural intelligence. Their ingenious structure enables bamboo to thrive and impacts its processing and utilization. As drying is an essential step in bamboo product manufacturing, in this study, the effects of the pith ring and cortex on the water loss, deformation, and cracking of bamboo at the macroscopic, tissue, and cellular levels were investigated. Our study revealed a previously unknown mechanism of bamboo drying deformation. The cortex significantly affected the rate of water loss, whereas the pith ring did not significantly reduce the drying rate. Three deformation mechanisms originating from the pith ring were identified: the cell structure and orientation, self-flattening during drying, and excellent bending performance in the chord direction. These pith ring characteristics led to a larger radius of the bamboo splits during drying. These findings expand our understanding of the natural intelligence of the inner and outer layers of bamboo and provide important insights into bamboo drying, deformation, cracking, bionics, and composite material manufacturing.
作者机构:
[Feng, Xiuxia] Shanghai Lida Univ, Sch Gen Educ & Foreign languages, Shanghai 201608, Peoples R China.;[Liu, Huying] Cent South Univ Forestry & Technol, SWAN Coll, Changsha 410211, Peoples R China.;[Liu, Huying] Stamford Int Univ, Grad Sch, Bangkok 10250, Thailand.
通讯机构:
[Liu, HY ] C;Cent South Univ Forestry & Technol, SWAN Coll, Changsha 410211, Peoples R China.;Stamford Int Univ, Grad Sch, Bangkok 10250, Thailand.
摘要:
This phenomenological study explored the experiences of language learners in the digital age, specifically investigating the intersection of digital literacy, technostress, online engagement, autonomy, and academic success. Twenty participants, selected through purposive sampling, shared Chinese as their native language and were between 18 and 20 years old, with five participants being female. Employing interviews and document analysis, the study aimed to understand the subjective meanings, emotions, and perceptions associated with these phenomena. The findings revealed the multifaceted nature of technostress, the crucial role of digital literacy in shaping online engagement and autonomy, and the nuanced impact on academic success. These qualitative insights contribute to a deeper understanding of the complex relationships in the digital language learning landscape. The study has implications for educators, materials developers, syllabus designers, and policy-makers, providing practical insights to enhance language learning experiences in the digital era. Future research may further explore specific dimensions uncovered in this study to adapt educational practices to the evolving digital terrain.
摘要:
Engelmann spruce (Picea engelmannii) is one of the most economically important tree species in the western United States. The species is widely distributed in mid- to high-elevation mountains, so its vulnerability to wind and snow is of concern to foresters. Height-to-diameter (H-D) ratio is an important metric for assessing tree stability and resistance to windstorm and icing damage. But our understanding of the variation in H-D ratio of Engelmann spruce and its driving mechanism is limited. Based on inventory data of 9004 Engelmann spruce trees from 997 permanent plots, this study used the random forest algorithm, an important machine learning method, to develop the H-D ratio model of Engelmann spruce related to competition, site condition, climate, topography and other environmental variables. We used cross-validation to train and optimize H-D ratio model, and then used variable importance ranking and partial dependence plot to quantify and analyze the effects of environmental factors on H-D ratio. Further, structural equation was used to perform path analysis between the response variable and the explanatory variables. The results reveal that competition contributes the most to changes in H-D ratio, followed by site index, topography and climate variables. The H-D ratio is positively affected by competition (DBH dominance and number of neighbors), site index, and May to September precipitation, but negatively affected by elevation. The results of path analysis indicate that the effects of elevation and May to September precipitation on H-D ratio can be mediated by site index. Although we sampled across broad climatic gradients, the effects of climate on H-D ratio were not as large as expected. In conclusion, competition is the primary driver for the variation in H-D ratio of Engelmann spruce, but the influence of environmental conditions including site quality, topography and climate on tree H-D ratio cannot be ignored. When designing management treatments for Engelmann spruce forests, we need to fully consider the potential effects of stand characteristics and environmental factors on tree stability.
摘要:
The dowel-bearing properties of a newly laminated flattened-bamboo (LFB) composite for engineering use was studied in this research by using the 5% bolt diameter offset method. The effects of specimen dimensions, bolt diameter, density, and bolt placed direction were included. Computed tomography (CT) and scanning electron microscope (SEM) were used to identify the failure type. The test results indicate that the parallel-to-grain dowel-bearing strength of LFB generally increased with an increasing density. When the bolt was placed along the LFB’s radial direction, the parallel-to-grain dowel-bearing strength approximately remained a constant (52 MPa) with the change of specimen dimensions and bolt diameter, while when the bolt was along the tangential direction, the dowel-bearing strength increased with the raising ratio of specimen thickness and bolt diameter. The first failure type was a crushing failure of bamboo fiber underneath the bolt, it happened when bolt diameter was small (12 mm and 14 mm) and placed along LFB’s radial direction. The second type was a splitting failure due to the lateral force generated by the bolt embedded into specimen, bamboo fiber splitting failure dominated for specimens with bolt along radial direction, while when bolt along tangential direction, glue layer splitting happened. The measured dowel-bearing strength was compared to the predictions obtained from equations in current wood specifications and articles. The results indicated that, except for the predicted values from the NDS equation (max error = 36%), which showed relatively reasonable agreement with the test values, the remaining predicted values exhibited discrepancies with the test values. To obtain proper predicted values, equations include density and ratio of specimen thickness and bolt diameter were proposed for calculation of LFB’s parallel-to-grain dowel-bearing strength.
摘要:
The optimization of explant selection and adjustment of plant growth regulators (PGRs) ratio may enhance the efficiency of micro-propagation of Gardenia jasminoides Ellis. The findings of the study suggest that the shoot tip proved to be the optimal explant for regenerating adventitious buds, with an impressive regeneration rate of 77.78% and the average number of adventitious buds being 2.86. The ideal medium consisted of Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (6-BA) at a 2 mg L-1, indoleacetic acid (IAA) at a 0.2 mg L-1, kinetin (KT) at 0.15 mg L-1, resulting in an outstanding regeneration rate of adventitious buds reaching up to 91.11%. For rooting purposes, the best medium was found be half-strength MS supplemented with indoleacetic acid (IAA) 0.5 mg L-1, achieving an rate for adventitious roots amounting to as high as 97.78%. The culture plantlets ultimately thrived, achieving an impressive transplanting survival rate of 93.33%. The application of PGRs was also found to enhance the regeneration of adventitious buds by increasing the ratios of endogenous hormones ZR/IAA and GA(3)/IAA. Additionally, it facilitated the differentiation of adventitious roots by elevating the ratios of endogenous hormones IAA/ZR, IAA/GA(3), and ABA/GA(3). Our study would provide a theoretical reference for the establishment of an efficient gardenia tissue culture system and the industrial production of gardenia.
摘要:
Antimony pollution is well recognized to induce cancer and deformity. By polymerization technique, a carbon aerogel microsphere (Ce@SCA) modified by Ce and S with micron size, well-developed pore structure, and large specific surface area was created. Ce@SCA exhibited the advantages of efficient selectivity and high adsorption capacity for Sb(III) in water. The highest adsorption capacity derived using the Sips isothermal model was 345.18 mg.g(-1), and the Sb (III) adsorption process was thermodynamically estimated as spontaneous, exothermic, and entropy-decreasing chemisorption. Meanwhile, Ce@SCA can convert highly toxic Sb(III) into Sb (V), which is suitable for the remediation of antimony-contaminated water bodies. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) were analyzed to elucidate the adsorption mechanism and to propose optimized adsorption configurations. A considerable number of -OH and -SH on the surface may increase the binding site of Sb, and the creation of S-Sb, O-Sb, and Ce-O-Sb covalent bonds was the key to Sb adsorption. This research provides a simple method for preparing cerium oxide-loaded and sulfur-doped carbon aerogel (Ce@SCA) with mild conditions and no hazardous waste, which also has superior adsorption properties for Sb (III) and high reusability.
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.
关键词:
Battery electric vehicle;Energy flow;Vehicle test;Integrated simulation;Driving cycles
摘要:
To comprehensively investigate the energy distribution and performance of a battery electric vehicle (BEV), an integrated simulation model based on energy flow test data was developed and validated, and the energy flow characteristics of the BEV throughout the entire driving range in low-temperature conditions were studied. The results show that the battery heat loss and motor energy loss first increase and then decrease with an increment in cycle number, while the transmission loss first decreases and then remains constant. The energy recovery efficiency demonstrates an incremental trend with the number of cycles post-battery charging, while the energy utilization efficiency experiences a decline due to escalating energy losses within the power distribution unit (PDU). The energy flow characteristics of the BEV exhibit a pronounced connection with the speed properties inherent in the driving cycle. The battery charge energy is maximal under Urban Dynamometer Driving Schedule (UDDS), whereas the electricity consumption per 100 km is minimized under China light-duty vehicle test cyclepassenger (CLTC-P). Conversely, the energy utilization and recovery efficiency are the highest under Worldwide Light-duty Test Cycle (WLTC). These findings provide directional insights, theoretical support and data basis for rational performance evaluation and optimal energy distribution of BEVs.
关键词:
the three-terminal ballistic junction;the alpha-T-3 lattie;the anisotropic transport
摘要:
The three-terminal ballistic junction (TBJ) has promising applications in nanoelectronics. We investigate the transport properties of aα-T(3)-based TBJ, where two typical configurations are considered, i.e. the A- and Z-TBJ. It is found that both A- and Z-TBJ exhibit transmission anisotropy, and the transmission of the A-TBJ has stronger anisotropy than that of the Z-TBJ. The amplitude of the rectification coefficient is smaller than that of phosphorene TBJ, but larger than that of graphene TBJ. When the symmetrical input is applied, the output voltage curve exhibits symmetric behavior. While in the case of asymmetric input, the symmetric behavior is broken, and the maximum value of the output voltage can reach a positive value. Interestingly, the voltage output shows a dramatic nonlinear response which may be useful for the voltage diode application with a push-pull input voltage. In addition, the heat fluxes of the asymmetric input are much smaller than those of the symmetric input. The maximum value of the heat flux under the symmetric input exceeds twice of that under the asymmetric input. Our results are useful to design nanoelectronic devices based onα-T(3)TBJ.
摘要:
In eukaryotic cells, epigenetic modifications of DNA and histone play an important role in the regulation of gene expression. ROXY19 is a member of the plant specific CC-type glutaredoxins (GRXs). We found previously that ROXY19, by association with the TOPLESS/TOPLESS-related (TPL/TPR) family, strongly repressed a subset of genes which were positively regulated by the class II TGA factors. Arabidopsis plants ectopic expressing ROXY19 (ROXY19OE) were hypersensitive to xenobiotic chemicals due to the silencing of detoxification pathway genes. Here, we confirmed in vivo the interaction between ROXY19 and TPL. In order to understand the molecular mechanism underlying ROXY19-TPL module mediated gene repression, DNA methylation and histone deacetylation inhibitors were applied to assess the involvement of epigenetic modifications in the silencing of detoxification pathway genes in ROXY19OE plants. Promoter regions of some ROXY19 repressed genes were not methylated in wild-type/Col-0, and the methylation status were not altered in ROXY19OE. Furthermore, we investigated the role of epigenetic modifications in the antagonistic interplay between ethylene/jasmonic acid (ET/JA) and salicylic acid (SA) signaling pathways, which were supposed to be regulated by ROXY19.
作者:
Li Ji;Song Sheng;Fangyuan Shen;Lili Yang;Shizhi Wen;...
期刊:
CATENA,2024年237:107816 ISSN:0341-8162
通讯作者:
Li Ji<&wdkj&>Xu Wang<&wdkj&>Lixue Yang
作者机构:
[Song Sheng; Lili Yang; Shizhi Wen; Gongxiu He] School of Forestry, Central South University of Forestry and Technology, 410004 Changsha, PR China;[Fangyuan Shen; Lixue Yang] Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, 150040 Harbin, PR China;Hunan Key Laboratory for Conservation and Utilization of Biological Resources in the Nanyue Mountainous Region, Hengyang Normal University, 421008 Hengyang, PR China;School of Life Science, Hengyang Normal University, 421008 Hengyang, PR China;[Xu Wang] Research Institute of Tropical Forestry, Chinese Academy of Forestry, 510520 Guangzhou, PR China
通讯机构:
[Li Ji] S;[Xu Wang] R;[Lixue Yang] K;Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, 150040 Harbin, PR China<&wdkj&>Research Institute of Tropical Forestry, Chinese Academy of Forestry, 510520 Guangzhou, PR China<&wdkj&>School of Forestry, Central South University of Forestry and Technology, 410004 Changsha, PR China<&wdkj&>Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, 150040 Harbin, PR China
摘要:
Soil bacteria, as integral components of the soil microbial community, play pivotal roles in biogeochemical cycles and ecosystem functions in boreal forests. The altitudinal patterns of soil bacteria have been widely reported, but their community assembly is uncertain. Here, we investigated the soil bacterial community attributes (diversity, taxonomic and functional composition, and bacterial interactions) and ecological processes associated with community assembly on Mt. Oakley in the northern Greater Khingan Mountains via Illumina MiSeq sequencing and functional annotation tools. The alpha diversity indices of the soil bacteria exhibited a progressively decreasing trend with increasing altitude across seasons. The relative abundance of the dominant bacterial taxa was more sensitive to altitude than to season. More complex (more nodes and links) bacterial interactions were detected at the lowest and highest altitudinal sites, as well as in September. The variations in the taxonomic and functional compositions of the soil bacteria induced by altitude were mainly driven by the variations in soil pH and extracellular enzyme activities. Stochastic (dispersal limitation and drift) processes largely controlled the soil bacterial community assemblages across spatiotemporal scales. The community assemblages of soil bacteria were affected by altitude-induced changes in the taxonomic composition and functional groups. Collectively, our results have significant implications for understanding bacterial biogeography and community assembly mechanisms along altitudinal gradients in boreal forest ecosystems.