摘要：
<jats:p>Bamboo contains water-soluble saccharides and carboxylic acid which have an anticoagulation effect on Portland cement, and the anticoagulation ingredients can directly influence the hydration reaction extent. Hydration product varieties and hydration product-bamboo shaving binding interfaces of the Portland cement, and finally the mechanical properties of bamboo cement particle boards. In this paper, bamboo shavings are pretreated by carbonizing treatment, hydro-thermal treatment and alkali treatment; high performance liquid chromatography is adopted to analyze the influences of three different pretreatment methods on contents of water-soluble saccharides and carboxylic acid in the bamboo shavings; a Fourier infrared spectrometer and an X-ray diffractometer are respectively utilized to analyze the characteristic peak changes and crystallization property changes of chemical ingredients of the bamboo shavings before and after the three types of pretreatment. This paper discusses effects of three types of pretreatment methods in eliminating water-soluble saccharides and carboxylic acid in the bamboo shavings. Bamboo Portland cement particle boards was prepared using bamboo shavings, which are pretreated in three ways, and influences and mechanisms of different pretreatment methods on properties of the bamboo Portland cement particle boards were studied. Research indicates that the mechanical properties of the Portland cement particle board prepared from bamboo shavings pretreated with 3 % NaOH solution are superior to requirements of qualified products and superior products specified in the Standard.</jats:p>
摘要：
During manufacturing processes, alloys face increasingly demanding requirements for their mechanical and tribological properties, underscoring the importance of revealing their deformation mechanisms. This study employed molecular dynamics simulation to construct models of FeCrNi (C1), FeCoCrNi (C2), FeCrNiCu (C3), and FeCoCrNiCu (C4), investigating the tribological properties of C1 alloy under various conditions and the mechanical properties across a wide temperature range (223-1073 K). The results indicate that the elastic modulus of the alloys follows the order C2 > C4 > C3 > C1 across the temperature range of 223 K to 1073 K. The elastic modulus increases with rising temperatures and decreases before rising once again as temperatures decrease. The phase transitions become more pronounced below 300 K. The addition of Co elements to the FeCrNi alloy contributes to fine-grain strengthening, uniform distribution of internal stress and strain, reduction in local stress concentration, and improvement of the alloy ductility and tensile strength. Compared to sliding friction, rolling friction reduces the number of worn atoms; however, the tensile and shear effects cause an increase in the stress gradient, leading to more severe subsurface damage and shear deformation. Temperature significantly affects the tribological properties of the alloys: phase transitions at high temperatures promote dislocation slip and plastic deformation, while at low temperatures, higher hardness and strength are observed. The roughness of stacking faults is greatly influenced by temperature, with an increase at the low-temperature range (223-273 K), a decrease in the mid-temperature range (273-673 K), and a smoother surface at the high-temperature range (673-1073 K). The research aims to provide a deeper understanding of the excellent mechanical and tribological properties of FeCrNi alloy at the micro/nano scales, thereby advancing their application and development in manufacturing processes.
摘要：
Antibiotic pollution that often leads to the increases in the prevalence of resistance represents unneglectable risks to human health. Photocatalysis shows great potential in addressing the antibiotic pollution issue. However, developing photocatalysts integrating full-spectrum photocatalysis and self-adaptive antibacterial performances still remains challenges due to the limited utilization rate of light and carrier transfer capacity. Herein, a musselinspired anchoring strategy was employed to fabricate polydopamine coated Hydrothermal carbon carbide ZIF8ZnO (PDA@HTCC/ZIF-8ZnO) heterojunction photocatalyst. The PDA coating was used as a transition layer to promote the heterogeneous nucleation of ZIF-8 on HTCC. Benefiting from the interfacial connections formed by metal coordination interactions between catechol groups of PDA coating and metal sites of ZIF-8, the carrier transfer capacity of PDA@HTCC/ZIF-8ZnO was improved and the range of light that can be utilized for the PDA@HTCC/ZIF-8ZnO was broadened. Therefore, the PDA@HTCC/ZIF-8ZnO heterojunction presented outstanding full-spectrum photocatalytic degradation and antibacterial performances. The full-spectrum degradation efficiency of tetracycline by PDA@HTCC/ZIF-8ZnO reached 98.7 % in 50 min. Moreover, the antimicrobial efficacy of PDA@HTCC/ZIF-8ZnO against E. coli exceeded 90 % under both light and dark conditions. The promotion effect of PDA transition layer on electrons transfer has been confirmed by DFT calculations. Under light irradiation, PDA@HTCC/ZIF-8ZnO gradually degrades tetracycline through demethylation, deamination, decarboxylation reactions, and ring-opening reactions, ultimately generating CO2 and H2O. This innovative strategy benefits the future heterojunction photocatalysts design for efficient solution of antibiotics pollution and the derivative drug-resistant bacteria issues.
作者：
Su, Jiahui;Yang, Yadong;Wan, Caichao*;Li, Xingong;Chai, Yaling;...
期刊：
研究(英文),2024年7:0317 ISSN：2096-5168
通讯作者：
Wan, Caichao;Wu, YQ;Wan, CC
作者机构：
[Yang, Yadong; Li, Xingong; Wu, Yiqiang; Yuan, Jianzhong; Wan, Caichao; Chai, Huayun; Su, Jiahui; Wan, CC; Chai, Yaling] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Wan, Caichao; Wan, CC] Yihua Lifestyle Technol Co Ltd, Shantou 515834, Peoples R China.
通讯机构：
[Wu, YQ ; Wan, CC] C;[Wan, CC ] Y;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;Yihua Lifestyle Technol Co Ltd, Shantou 515834, Peoples R China.
摘要：
<jats:p>
Silica glass, known for its brittleness, weight, and non-biodegradable nature, faces challenges in finding suitable alternatives. Transparent wood, made by infusing polymers into wood, shows promise but is hindered by limited availability of wood in China and fire risks associated with its use. This study explores the potential of utilizing bamboo, which has a shorter growth cycle, as a valuable resource for developing flame-retardant, smoke-suppressing, and superhydrophobic transparent bamboo. A 3-layered flame-retardant barrier, composed of a top silane layer, an intermediate layer of SiO
<jats:sub>2</jats:sub>
formed through hydrolysis-condensation of Na
<jats:sub>2</jats:sub>
SiO
<jats:sub>3</jats:sub>
on the surface, and an inner layer of Na
<jats:sub>2</jats:sub>
SiO
<jats:sub>3</jats:sub>
, has been confirmed to be effective in reducing heat release, slowing flame spread, and inhibiting the release of combustible volatiles, toxic smoke, and CO. Compared to natural bamboo and other congeneric transparent products, the transparent bamboo displays remarkable superiority, with the majority of parameters being notably lower by an entire order of magnitude. It achieves a long ignition time of 116 s, low total heat release (0.7 MJ/m
<jats:sup>2</jats:sup>
), low total smoke production (0.063 m
<jats:sup>2</jats:sup>
), and low peak CO concentration (0.008 kg/kg). Moreover, when used as a substrate for perovskite solar cells, the transparent bamboo displays the potential to act as a light management layer, leading to a marked efficiency enhancement of 15.29%. The excellent features of transparent bamboo make it an enticing choice for future advancements in flame-retardant glasses and optical devices.
</jats:p>
作者机构：
[Yang, Yadong; Zhu, Yuan; Zhang, Zhe; Xie, Yuzhong; Zhou, Zaiyang; Li, Xingong; Wu, Yiqiang; Li, Liangli; Wan, Caichao; Chai, Huayun; Liu, Xinyi; Wan, CC] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Liu, Sulai] Hunan Prov Peoples Hosp, Dept Hepatobiliary Surg, Changsha 410000, Peoples R China.;[Yang, Zhenxu] Univ Sydney, Sch Biomed Engn, Sydney, NSW 2006, Australia.;[Zhao, Xinpeng] Michigan State Univ, Dept Mech Engn, E Lansing, MI 48824 USA.
通讯机构：
[Wu, YQ ; Wan, CC] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
energy efficiency;future buildings;multifunctional;transparent wood;ultraviolet shielding
摘要：
Indoor UV damage is a serious problem that is often ignored. Common glasses cannot filter UV rays well and have fragility and environmental issues. UV-shielding transparent wood (TW) holds promise, yet striking the right balance between blocking UV rays and allowing sufficient visible-light transmission poses a challenge. The pronounced capillary force, fueled by persistent moisture and extractives in wood, alongside the existence of multiphase interfaces, collectively hinder the uniform penetration of polymers and the effective dispersion of nanomaterials within the wood skeleton. Here, we incorporate high-pressure supercritical CO(2) fluid-assisted impregnation (HSCFI) into fabricating UV-shielding TW. The supercritical CO(2) pretreatment efficiently eliminates moisture and refines wood structure by extracting polar substances, resulting in a prominent 52.4% increase in average water permeability. Subsequently, this HSCFI method facilitates the infiltration of methyl methacrylate (MMA) monomer and Ce-ZnO nanorods (NRDs) into the refined anhydrous wood, leveraging the excellent solvency of supercritical CO(2) for MMA. The impregnation rate of PMMA undergoes a substantial increase from 34.5 to 59.1%. With the robust UV-blocking capability of Ce-ZnO NRDs, thanks to dual-valence Ce doping widening the ZnO energy gap via the Burstein-Moss effect and their unique photoactive microstructure featuring a solid prism with a sharp hexahedral pyramidal tip, along with intrinsic physical scattering/reflection actions, Ce-ZnO NRDs@TW achieves an impressive 99.6% UVA radiation blockage (the highest for TW) and maintains high visible-light transmission (83.2%). Furthermore, Ce-ZnO NRDs@TW presents favorable energy-saving, sound absorption, and antifungal abilities, making it a promising candidate for future green buildings.
摘要：
Gypsum-based composites were prepared via a slurry casting process using construction gypsum as the binding material and poplar fibers as reinforcing material. The effects of different fiber content and curing time on the mechanical properties, water resistance, and flame retardancy of these composites were investigated, and the influence mechanism was characterized by infrared spectroscopy, scanning electron microscopy, and X-ray diffractometry. The results showed that the best composite mechanical strength was achieved with 10% poplar fiber- content, and the absolute dry flexural and compressive strengths reached 3.59 and 8.06 MPa, respectively. Compared with pure gypsum, the flexural strength and compressive strength increased by 10% and 19%, respectively. The inclusion of fibers somewhat prevented the migration of free water within the composites and enhanced their water resistance. At 10% fiber content, the composite's 24 h water absorption rate was 34.3%, 8% lower than that of pure gypsum, with a softening coefficient of 0.55. However, fiber content increases the porosity of gypsum-based composites. When heated, this increased porosity accelerates' heat conduction within the matrix, raising the peak and total exothermic rates, thereby weakening the composites' inherently flame-retardant properties. Poplar-fiber-reinforced gypsum-based composites offered superior performance in commercial applications, compared to pure gypsum board, providing a sustainable and green alternative for ceilings, partitions, and other applications, while broadening the prospects for gypsum-based composites in the engineering field.
期刊：
Colloids and Surfaces A: Physicochemical and Engineering Aspects,2024年703:135325 ISSN：0927-7757
通讯作者：
Xingong Li
作者机构：
[Yunpeng Ye; Shusen Zhang; Chengliang Zhou; Xingong Li] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
通讯机构：
[Xingong Li] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China
作者机构：
[Deng, Pingping; Li, Xingong; Yan, Xiaofan; Zhang, Zuoyu; Ding, Tingting; Wu, Zhiping] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Zhiping Wu] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan410004, China
摘要：
Temperature plays an important role in anaerobic digestion (AD), and different substrates have different optimum temperatures in AD. However, the effect of temperature on the performance of AD when cellulosic ethanol wastewater was used as a substrate was rarely reported. Therefore, the digestion characteristics of cellulosic ethanol wastewater at 25, 35, 45, and 55 degrees C were investigated, and the microbial communities of the sludge sample were analyzed after fermentation. The results showed that the cumulative methane production was the highest at 55 degrees C, 906.40 +/- 50.67 mL/g VS, which was 81.06, 72.42, and 13.33% higher than that at 25, 35, and 45 degrees C, respectively. The content of methane was 68.13, 49.26, 70.46, and 85.84% at the terminal period of fermentation at temperatures of 25, 35, 45, and 55 degrees C, respectively. The testing of volatile fatty acids (VFAs) indicated that the accumulation of VFAs did not occur when the fermentation was carried out at 25, 35, and 45 degrees C; however, the VFA content at 55 degrees C was much larger than that in the three groups (25, 35, and 45 degrees C), and the ratio of propionic acid to acetic acid was larger than 1.4 at the late stage of fermentation, so it inhibited the fermentation. The diversity of the microbial community indicated that the floral structure and metabolic pathway of fermentation were alike at 25 and 35 degrees C. Firmicutes and Proteobacteria were the main flora covering the 25-55 degrees C-based phylum or below it. The relative abundance of Methanosaeta was the highest when fermentation temperatures were 25 and 35 degrees C; however, its relative abundance decreased sharply and the relative abundance of Methanosarcina increased substantially when the temperature increased from 35 to 45 degrees C, which indicated that Methanosarcina can exist in higher temperatures. At the same time, hydrogenotrophic methanogens such as Methanoculleus and Methanothermobacter were dominant when fermentation temperatures were 45 and 55 degrees C, which indicated that the metabolic pathway changed from acetoclastic methanogenesis to hydrogenotrophic methanogenesis.
作者机构：
[Li, Xingong; Yin, Canbin] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Yin, Canbin] Hunan City Univ, Yiyang 413000, Peoples R China.
通讯机构：
[Xingong Li] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
摘要：
Bamboo contains water-soluble saccharides and carboxylic acid which have an anticoagulation effect on Portland cement; the anticoagulation ingredients can directly influence the adaptability of the Portland cement and bamboo shavings and finally influence the mechanical properties of bamboo Portland cement particle board. In order to improve the adaptability of bamboo and the Portland cement, bamboo shavings are pretreated with 1% NaOH solution, 2% NaOH solution, or 3% NaOH solution. High-performance liquid chromatography is adopted to analyze the influences of treatment based on different concentrations of NaOH solutions on the content of water-soluble saccharides and carboxylic acid in the bamboo shavings, and a Fourier infrared spectrometer and an X-ray diffractometer are utilized to analyze the characteristic peak changes and crystallization property changes, respectively, of the chemical ingredients of the bamboo shavings before and after the three types of pretreatment. This paper discusses the effects of treatment based on different concentrations of NaOH solutions in eliminating water-soluble saccharides and carboxylic acid in the bamboo shavings, details the preparation of bamboo Portland cement particle board by use of the bamboo shavings before and after pretreatment, and reports the influences and mechanisms of NaOH pretreatment on properties of the bamboo Portland cement particle board. Research indicates that the mechanical properties of the Portland cement particle board prepared from bamboo shavings treated with 3% NaOH solution exceed the requirements of qualified products and superior products specified in the Standard GB/T24312-2009.
作者机构：
[夏琪琪; 朱凌波; 李新功; 郑霞] College of Material Science and Engineering, Central South University of Forestry & Technology, Changsha;410000, China;[夏琪琪; 朱凌波; 李新功; 郑霞] 410000, China
通讯机构：
[Li, X.] C;College of Material Science and Engineering, China
