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Physicochemical and Thermal Properties of Some Key Tropical Sawdust Woods for Energy Production
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作者 Davy Fiwa Kaoke Yann Le Brech +2 位作者 Emmanuel Talla Anthony Dufour Patrick Mountapmbeme Kouotou 《Journal of Sustainable Bioenergy Systems》 2024年第1期1-22,共22页
In South Saharan countries, 85% of the population uses biomass as a primary energy source. Cameroon presents one of the highest biomass energy and sawmills produce important sawdust resources which are not used and ar... In South Saharan countries, 85% of the population uses biomass as a primary energy source. Cameroon presents one of the highest biomass energy and sawmills produce important sawdust resources which are not used and are burnt in piles leading to significant air toxic emissions. Therefore, we have to valorize industrially these available sawdusts. This study focuses on the physicochemical and thermochemical analysis of Ayous, Sapelli and Tali sawdust. The proximate and ultimate analysis, particle size, structural composition, as well as heavy metal content and calorific value were determined. In addition, the thermogravimetric mass losses were also estimated. The results showed that high water contents (24% - 41%) were recorded in the raw sawdust, and the thermal treatment reduced these contents from 78% to values in the range of 4% - 9%. The values for ash and volatile matter content were respectively between 0.25% - 0.74% and 68% - 76%. The LHV is higher in Ayous (17.5 MJ/kg) and Sapelli (16.8 MJ/kg) than that of Tali (15.7 MJ/kg). The concentration of heavy metals is very low in each species. Extractives are more present in Tali (16.06%) than in the other sawdusts. Pyrolysis of sawdust shows the typical decomposition of hemicellulose (270˚C - 325˚C), cellulose (325˚C - 400˚C) and lignin (200˚C - 550˚C) with a maximum loss of 75% at 370˚C and the melting point is 320˚C. The results of the sawdust parameters determined in the paper can be valorized to reduce pollutants emissions by developing the efficiency and effectiveness of biomass energy processes and promoting the use of biomass as a sustainable alternative to traditional fossil fuels. 展开更多
关键词 wood SAWMILLS SAWdust Combustion Energy
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尺度适应性起沙机制在CMA-CUACE/Dust中的应用
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作者 周春红 饶晓琴 +6 位作者 盛黎 张健 陆建燕 林建 胡江凯 张碧辉 徐冉 《应用气象学报》 CSCD 北大核心 2024年第4期400-413,共14页
沙尘暴是影响我国重要的灾害性天气之一,针对中国气象局亚洲沙尘暴数值预报系统CMA-CUACE/Dust(China Meteorological Administration Unified Atmospheric Environment for Dust)的沙尘质量浓度在中亚高估、蒙古北部低估、在我国消散... 沙尘暴是影响我国重要的灾害性天气之一,针对中国气象局亚洲沙尘暴数值预报系统CMA-CUACE/Dust(China Meteorological Administration Unified Atmospheric Environment for Dust)的沙尘质量浓度在中亚高估、蒙古北部低估、在我国消散过快以及极端沙尘暴预报峰值偏低等问题,应用与模式格距匹配的尺度适应性起沙机制并更新风蚀资料库对模式进行改进。对2021年3月13—17日东亚最强沙尘暴个例和2023年3—5月与业务运行环境一致的连续预报试验表明,改进后的模式(CMA-CUACE/Dust V1.5)有效改善了上述不足,极端沙尘暴过程传输至我国后的沙尘质量浓度峰值与观测接近。连续预报试验TS(threat score)评分显示:CMA-CUACE/Dust V1.5预报一致性和连续性较好,1~5 d不同时效预报TS评分明显高于改进前和韩国模式ADAM(the Asian Dust Aerosol Model),漏报率明显降低,对2023年5次沙尘过程的4次预报TS评分高于0.3,部分过程超过0.5。 展开更多
关键词 沙尘暴数值预报 CMA-CUACE/dust V1.5 尺度适应性 起沙机制 风蚀资料库
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基于YOLOv7的木材缺陷检测模型Wood-Net的研究
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作者 王正 江莺 +3 位作者 严飞 孙佑鹏 张园 张柳磊 《林业工程学报》 CSCD 北大核心 2024年第1期132-140,共9页
为改善利用人工方式识别木材缺陷存在的效率低、人工成本高的问题,同时实现在木材加工过程中使用新兴方式对不同的缺陷进行快速准确检测以提高木材利用率,针对现有的目标检测网络在木材缺陷检测方面存在诸如检测精度低、报错率高以及识... 为改善利用人工方式识别木材缺陷存在的效率低、人工成本高的问题,同时实现在木材加工过程中使用新兴方式对不同的缺陷进行快速准确检测以提高木材利用率,针对现有的目标检测网络在木材缺陷检测方面存在诸如检测精度低、报错率高以及识别种类少等局限,设计了用于木材缺陷检测的深度学习网络Wood-Net。Wood-Net将注意力机制ECA(efficient channel attention module)引入YOLOv7的主干网络,以便更好地区分木材缺陷之间的细微差别;将ECA与Res2Net结合后形成ECA-Res2Net模块,ECA-Res2Net模块克服了单纯的Res2Net跨通道交流能力不足的问题,增强了网络对更细粒度特征的提取能力;将ECA-Res2Net模块与SPPCSPC(spatial pyramid pooling and channel spatial pyramid convolution)并联形成ResSPPCSPC模块,增加了描述图像本身特征数量的能力,由此构成新方法Wood-Net。本研究将准确度、召回值、mAP@0.5以及mAP@0.5∶mAP@0.95 4个数值作为系统性能的评价指标。利用自建数据集训练Wood-Net,得到试验数据。试验结果表明:Wood-Net模型比基准模型YOLOv7在木材优选上精确率提高了4.52%,mAP@0.5∶mAP@0.95提高了6.62%;比基准模型YOLOv5s在木材优选上精确率提高了6.79%,mAP@0.5∶mAP@0.95提高了5.67%。ECA注意力机制能够有效提升E-ELAN的通道间信息交互能力;Res2Net模块具有很强的细粒度特征提取能力,在网络中引入Res2Net模块后,网络各项性能指标收敛速度快,在Res2Net中加入ECA后能够使单纯的Res2Net考虑多通道特征之间的关系,完成信息融合,提高检测性能。 展开更多
关键词 wood-Net 木材优选 ECA-Res2Net ECA Res2Net
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Deflagration characteristics of freely propagating flames in magnesium hydride dust clouds 被引量:1
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作者 Qiwei Zhang Yangfan Cheng +2 位作者 Beibei Zhang Danyi Li Zhaowu Shen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期471-483,共13页
The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the... The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed camera.The dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were analyzed.The experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,respectively.The dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were smaller.The flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of particles.The falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,respectively.While the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the flame.Furthermore,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)dust.The combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg dust.The micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction. 展开更多
关键词 Magnesium hydride dust Flame combustion mechanism Particle size dust explosion Two-color pyrometer
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An Evaluation of the Physicochemical, Structural and Morphological Properties of Selected Tropical Wood Species for Possible Utilization in the Wood Industry
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作者 Jude I. Duruaku Patrick A. C. Okoye +3 位作者 Nkechi H. Okoye Joseph O. Nwadiogbu Valentine I. Onwukeme Rosemary U. Arinze 《Journal of Sustainable Bioenergy Systems》 2023年第4期131-148,共18页
This work investigated and quantified the physicochemical, structural and morphological properties of four (4) tropical timbers as precursor raw materials for possible utilization in the wood plastic industry. The phy... This work investigated and quantified the physicochemical, structural and morphological properties of four (4) tropical timbers as precursor raw materials for possible utilization in the wood plastic industry. The physicochemical properties of the wood samples such as the bulk and tapped density, moisture content, water absorption capacity at 25°C, volatile content, fixed carbon, ash content, alpha cellulose, hemicellulose, lignin, and extractives contents were determined using standard methods like the European Committee for Standardization and (CEN/TS) and the American Society for Testing Materials (ASTM) standards. The structural and morphological properties of the samples were examined with Fourier Infrared Transform (FTIR) spectroscopy and scanning electron microscope (SEM). Results indicated that the bulk density values of the timbers ranged from 0.34 g/cm<sup>3</sup> in Brachystegia eurycoma (W<sub>3</sub>) to 0.47 g/cm<sup>3</sup> in Erythrophleum suaveolens (W<sub>2</sub>), with the other timbers, Nuclea diderichii (W<sub>1</sub>) and Prosopis africana (W<sub>4</sub>) having the same bulk density of 0.40 g/cm<sup>3</sup>. With respect to their moisture content, W<sub>2</sub> had the highest value (8.38%) while Nauclea diderrichii had the lowest value (6.52%). The water absorption capacities of the woods studied correlated with the cellulose composition of wood in the order of: W<sub>3</sub> > W<sub>1</sub> > W<sub>4</sub> > W<sub>2</sub>. The FTIR results showed that W<sub>2</sub> and W<sub>3</sub> presented a slightly more prominent and broader band than the other woods at 1731 cm<sup>-1</sup>, in agreement with the higher holocellulose content of these species, while W<sub>2</sub> and W<sub>4</sub> presented the most prominent peaks indicating higher lignin content than W<sub>1</sub> and W<sub>3</sub>. The SEM micrographs of the wood flour samples investigated indicated that the surfaces of the woods were rough and heterogeneous with irregular crystal and brick shaped particles. A two-way analysis of variance (ANOVA) carried out with respect to the chemical composition of the wood samples indicated that there was no statistically significant variation in the wood chemical composition between species as the p-value (0.852) obtained was greater than the critical level of α = 0.05. 展开更多
关键词 wood Plastic Composites Density Water Absorption Capacity CELLULOSE Sustainability
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Physicomechanical Properties of Sustainable Wood Plastic Composites of Tropical Sawdust and Thermoplastic Waste for Possible Utilization in the Wood Industry
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作者 Jude I. Duruaku Patrick A. C. Okoye +3 位作者 Theresa U. Onuegbu Valentine I. Onwukeme Nkechi H. Okoye Joseph O. Nwadiogbu 《Journal of Sustainable Bioenergy Systems》 2023年第4期149-171,共23页
This work investigated and quantified the physicomechanical properties of flat-pressed wood plastic composites produced with recycled polyethylene terephthalate, recycled polyethylene and sawdust derived from selected... This work investigated and quantified the physicomechanical properties of flat-pressed wood plastic composites produced with recycled polyethylene terephthalate, recycled polyethylene and sawdust derived from selected tropical timbers, namely, Nauclea diderrichii, Brachystegia eurycoma, Erythrophleum suaveolens and Prosopis africana, for possible utilization in the wood industry. The compounding of the polymer blends of the precursor plastics, namely recycled PET (rPET) and recycled PE (rPE) with the sawdust (SD) from the selected timbers to produce the desired wood rPET/rPE composites was carried out via the flat press method. The characterization of the physicomechanical properties of the wood plastic composites (WPCs) produced, such as the density, hardness, flexural strength, ultimate tensile strength, elongation %, thickness swelling and water absorption capacity was carried out using methods based mainly on the European Committee for Standardization (CEN) and the American Society for Testing Materials (ASTM) standards. The results of the investigation on the resultant composites indicated that changes in the SD content affected the density of flat-pressed WPCs in line with literature. Generally, it was observed that as wood dust increased and PET content decreased, the density of composites decreased with some deviations as expected probably due to the anisotropic nature of the wood fillers. The analysis of variance (ANOVA) revealed that there was a statistically significant variation in the wood composites of Nuclea diderichii based on the physicomechanical values as the p-value (0.020) obtained was less than the critical level of α = 0.05. It was also observed that the composite, Wood 1 Sample 5 (W<sub>1</sub>S<sub>5</sub>) which was composed of 40% rPE, 40% rPET and 20% SD (derived from Nuclea diderichii), had the highest percentage elongation (26.84%);the highest flexural strength (14.995 N/mm<sup>2</sup>) and possibly the least carbon footprint in the environment. These properties of W<sub>1</sub>S<sub>5</sub> suggest that it could therefore be the best option for the production of building materials like ceiling boards or floor skirting in the wood plastic composite industry. The results of these investigations have therefore indicated that the fabrication of WPCs from sawdust and rPET/rPE was technically feasible and had prospects for large scale production in the wood industry. 展开更多
关键词 wood Plastic Composites Density Water Absorption Capacity CELLULOSE Sustainability RECYCLE Waste
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Effects of dust controls on respirable coal mine dust composition and particle sizes:case studies on auxiliary scrubbers and canopy air curtain
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作者 F.Animah C.Keles +1 位作者 W.R.Reed E.Sarver 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第3期86-101,共16页
Control of dust in underground coal mines is critical for mitigating both safety and health hazards.For decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effective... Control of dust in underground coal mines is critical for mitigating both safety and health hazards.For decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effectiveness of various dust control technologies in coal mines.Recent studies have included the evaluation of auxiliary scrubbers to reduce respirable dust downstream of active mining and the use of canopy air curtains(CACs)to reduce respirable dust in key operator positions.While detailed dust characterization was not a focus of such studies,this is a growing area of interest.Using preserved filter samples from three previous NIOSH studies,the current work aims to explore the effect of two different scrubbers(one wet and one dry)and a roof bolter CAC on respirable dust composition and particle size distribution.For this,the preserved filter samples were analyzed by thermogravimetric analysis and/or scanning electron microscopy with energy dispersive X-ray.Results indicate that dust composition was not appreciably affected by either scrubber or the CAC.However,the wet scrubber and CAC appeared to decrease the overall particle size distribution.Such an effect of the dry scrubber was not consistently observed,but this is probably related to the particular sampling location downstream of the scrubber which allowed for significant mixing of the scrubber exhaust and other return air.Aside from the insights gained with respect to the three specific dust control case studies revisited here,this work demonstrates the value of preserved dust samples for follow-up investigation more broadly. 展开更多
关键词 Respirable dust dust control SEM–EDX SCRUBBER Canopy air curtain SILICA
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Vibration properties of Paulownia wood for Ruan sound quality using machine learning methods
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作者 Yang Yang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期216-222,共7页
As an important material for manufacturing resonant components of musical instruments,Paulownia has an important influence on the sound quality of Ruan.In this paper,a model for evaluating the sound quality of Ruan ba... As an important material for manufacturing resonant components of musical instruments,Paulownia has an important influence on the sound quality of Ruan.In this paper,a model for evaluating the sound quality of Ruan based on the vibration characteristics of wood is developed using machine learning methods.Generally,the selection of materials for Ruan manufacturing relies primarily on manually weighing,observing,striking,and listening by the instrument technician.Deficiencies in scientific theory have hindered the quality of the finished Ruan.In this study,nine Ruans were manufactured,and a prediction model of Ruan sound quality was proposed based on the raw material information of Ruans.Out of a total of 180 data sets,145 and 45 sets were chosen for training and validation,respec-tively.In this paper,typical correlation analysis was used to determine the correlation between two single indicators in two adjacent pairwise combinations of the measured objects in each stage of the production process in Ruan.The vibra-tion characteristics of the wood were tested,and a model for predicting the evaluation of Ruan’s acoustic qualities was developed by measuring the vibration characteristics of the resonating plate material.The acoustic quality of the Ruan sound board wood was evaluated and predicted using machine learning model generalized regression neural net-work.The results show that the prediction of Ruan sound quality can be achieved using Matlab simulation based on the vibration characteristics of the soundboard wood.When the model-predicted values were compared with the tradi-tional predicted results,it was found that the generalized regression neural network had good performance,achieving an accuracy of 93.8%which was highly consistent with the experimental results.It was concluded that the model can accurately predict the acoustic quality of the Ruan based on the vibration performance of the soundboards. 展开更多
关键词 Sound quality wood vibration performance Paulownia wood Machine learning methods
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Wood灯检查在白癜风治疗期间不同复色模式观察研究中的应用
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作者 金伟梅 马杰 +2 位作者 索翠平 车旭 赵建斌 《中国美容医学》 CAS 2024年第5期103-107,共5页
目的:通过观察Wood灯下白癜风患者治疗过程中皮损的复色模式,探究不同复色模式的相关影响因素,分析评估不同复色模式间的疗效差异。方法:收集选取2021年8月-2022年8月笔者医院就诊的90例(170块),采集患者基本信息及病情相关指标。治疗后... 目的:通过观察Wood灯下白癜风患者治疗过程中皮损的复色模式,探究不同复色模式的相关影响因素,分析评估不同复色模式间的疗效差异。方法:收集选取2021年8月-2022年8月笔者医院就诊的90例(170块),采集患者基本信息及病情相关指标。治疗后,观察Wood灯下皮损复色模式,将复色模式与收集指标进行统计分析,筛选出差异有统计学意义的指标后,采用Logistic回归分析阳性指标与复色模式的相关性。并将Wood灯下观察的皮损面积作为疗效判定标准,分析对比不同复色模式间的疗效差异。结果:One-way ANOVA分析、χ^(2)检验显示白癜风疾病分期、皮损部位、治疗方式与皮损复色模式有关(P<0.05)。Logistic回归分析显示:治疗方式与复色模式存在相关性(P<0.05)。不同复色模式达到有效复色面积的时间比较,差异有统计学意义(H=8.04,P<0.05)。结论:通过观察Wood灯下白癜风患者治疗过程中皮损的复色模式发现,治疗方式可能是白癜风皮损复色模式的决定因素;不同复色模式之间的复色速度存在差异,可作为临床医师调整治疗方案的参考依据。 展开更多
关键词 白癜风 复色模式 治疗方式 复色速度 wood
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Biobased Furfurylated Poplar Wood for Flame-Retardant Modification with Boric Acid and Ammonium Dihydrogen Phosphate
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作者 Ming Ni Lei Li +4 位作者 Yiqiang Wu Jianzheng Qiao Yan Qing Ping Li Yingfeng Zuo 《Journal of Renewable Materials》 EI CAS 2024年第8期1355-1368,共14页
Furfurylated wood exhibits excellent dimensional stability and corrosion resistance,making it a promising material for constructing buildings,but it is highly flammable.Herein,flame-retardant furfurylated poplar wood ... Furfurylated wood exhibits excellent dimensional stability and corrosion resistance,making it a promising material for constructing buildings,but it is highly flammable.Herein,flame-retardant furfurylated poplar wood was produced via a two-step process utilizing boric acid(BA)and ammonium dihydrogen phosphate(ADP)as flame-retardant components,and biomass-derived furfuryl alcohol(FA)as a modifier.The acidity of BA and ADP allowed them to catalyze the polymerization of FA,which formed a cross-linked network that immobilized BA and ADP inside the wood.The addition of BA/ADP substantially delayed the time to ignition from 10 to 385 s and reduced the total heat release and total smoke release by 58.75%and 77.31%,respectively.Analysis of the pyrolysis process showed that the decomposition products of BA and ADP protected the underlying furfurylated wood and diluted combustible gases.This method significantly improved the fire retardancy and smokeless properties of furfurylated wood,providing promising prospects for its application as an engineering material. 展开更多
关键词 Poplar wood furfuryl alcohol furfurylated wood flame retardancy boric acid ammonium dihydrogen phosphate
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Filtration performance and modeling of granular bed for dust removal from coal pyrolytic vapors
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作者 Shuaiqiang Yang Lin Du +3 位作者 Guangchao Ding Runguo Liu Wenli Song Songgeng Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期35-42,共8页
Dust removal from pyrolytic vapors at high temperatures is an obstacle to the industrialization of the coal pyrolysis process.In this work,a granular bed with expanded perlites as filtration media was designed and int... Dust removal from pyrolytic vapors at high temperatures is an obstacle to the industrialization of the coal pyrolysis process.In this work,a granular bed with expanded perlites as filtration media was designed and integrated into a 10 t·d^(–1)coal pyrolysis facility.The testing results showed that around 97.56%dust collection efficiency was achieved.As a result,dust content in tar was significantly lowered.The pressure drop of the granular bed maintained in the range of 356 Pa to 489 Pa.The dust size in the effluent after filtration exhibited a bimodal distribution,which was attributed to the heterogeneity of the dust components.The effects of filtration bed on pyrolytic product yields were also discussed.A modified filtration model based on the macroscopic phenomenological theory was proposed to describe the performance of the granular bed.The computation results were well agreed with the experimental data. 展开更多
关键词 Granular bed filtration dust removal PYROLYSIS FILTRATION FIXED-BED
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Experimental and numerical simulation study on forced ventilation and dust removal of coal mine heading surface
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作者 Haotian Zheng Bingyou Jiang +1 位作者 Haoyu Wang Yuannan Zheng 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第1期204-220,共17页
In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar princ... In order to study the problems of unreasonable airflow distribution and serious dust pollution in a heading surface,an experimental platform for forced ventilation and dust removal was built based on the similar principles.Through the similar experiment and numerical simulation,the distribution of airflow field in the roadway and the spatial and temporal evolution of dust pollution under the conditions of forced ventilation were determined.The airflow field in the roadway can be divided into three zones:jet zone,vortex zone and reflux zone.The dust concentration gradually decreases from the head to the rear of the roadway.Under the forced ventilation conditions,there is a unilateral accumulation of dust,with higher dust concentrations away from the ducts.The position of the equipment has an interception effect on the dust.The maximum error between the test value and the simulation result is 12.9%,which verifies the accuracy of the experimental results.The research results can provide theoretical guidance for the application of dust removal technology in coal mine. 展开更多
关键词 Heading surface Forced ventilation Airflow field dust pollution
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Enhancing wood efficiency through comprehensive wood flow analysis:Methodology and strategic insights
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作者 Ruisheng Wang Peer Haller 《Forest Ecosystems》 SCIE CSCD 2024年第2期172-183,共12页
Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the ne... Wood,an essential natural resource in human civilization,remains widely used despite advances in technology and material substitution.The surge in greenhouse gas emissions and environmental concerns accentuates the need for optimizing wood utilization.Material flow analysis is a powerful tool for tracking material flows and stocks,aiding resource management and environmental decision-making.However,the full extent of its methodological dimensions,particularly within the context of the wood supply chain,remains relatively unexplored.In this study,we delve into the existing literature on wood flow analysis,discussing its primary objectives,materials involved,temporal and spatial scales,data sources,units,and conversion factors.Additionally,data uncertainty,data reconciliation and crucial assumptions in material flow analysis are highlighted in this paper.Key findings reveal the significance of wood cascading and substitution effects by replacing non-wood materials,where they can reduce greenhouse gas emissions more than the natural carbon sink of forests and wood products.The immediate impact of short-term wood cascading might not be as robust as the substitution effect,with energy substitution showcasing better results than material substitution.However,it's crucial to note that these conclusions could experience significant reversal from a long-term and global perspective.Strategies for improving wood efficiency involve maximizing material use,advancing construction technologies,extending product lifespans,promoting cascade use,and optimizing energy recovery processes.The study underscores the need for standardized approaches in wood flow analysis and emphasizes the potential of wood efficiency strategies in addressing environmental challenges. 展开更多
关键词 Material flow analysis wood METHODOLOGY Cascade use Substitution effects
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Ion acoustic solitary waves in an adiabatic dusty plasma:Roles of superthermal electrons,ion loss and ionization
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作者 饶强华 陈辉 +1 位作者 刘三秋 陈小昌 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第8期337-342,共6页
We investigate propagation of dust ion acoustic solitary wave(DIASW)in a multicomponent dusty plasma with adiabatic ions,superthermal electrons,and stationary dust.The reductive perturbation method is employed to deri... We investigate propagation of dust ion acoustic solitary wave(DIASW)in a multicomponent dusty plasma with adiabatic ions,superthermal electrons,and stationary dust.The reductive perturbation method is employed to derive the damped Korteweg-de Vries(DKdV)equation which describes DIASW.The result reveals that the adiabaticity of ions significantly modifies the basic features of the DIASW.The ionization effect makes the solitary wave grow,while collisions reduce the growth rate and even lead to the damping.With the increases in ionization cross sectionΔσ/σ_(0),ion-to-electron density ratioδ_(ie)and superthermal electrons parameterκ,the effect of ionization on DIASW enhances. 展开更多
关键词 dust ion acoustic wave solitary wave IONIZATION adiabatic process
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Evolutionary history shapes variation of wood density of tree species across the world
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作者 Fangbing Li Hong Qian +7 位作者 Jordi Sardans Dzhamal Y.Amishev Zixuan Wang Changyue Zhang Tonggui Wu Xiaoniu Xu Xiao Tao Xingzhao Huang 《Plant Diversity》 SCIE CAS CSCD 2024年第3期283-293,共11页
The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 m... The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree species.We assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density variation.We found that wood density displayed a significant phylogenetic signal.Wood density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into account.When angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for gymnosperms.Our study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density. 展开更多
关键词 wood density PHYLOGENY ANGIOSPERMS GYMNOSPERMS Climate factors Biophysical parameters
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Wood By-Products as UV Protection:A Consequence Review
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作者 Naglaa Salem El‑Sayed Mohamed Hasanin Samir Kamel 《Journal of Renewable Materials》 EI CAS 2024年第4期699-720,共22页
In recent decades,the ozone layer has suffered considerable damage,increasing the entry of ultraviolet(UV)light into the atmosphere and reaching the earth’s surface,negatively affecting life.Accordingly,researchers a... In recent decades,the ozone layer has suffered considerable damage,increasing the entry of ultraviolet(UV)light into the atmosphere and reaching the earth’s surface,negatively affecting life.Accordingly,researchers aimed to solve this problem by synthesizing advanced UV-shielding materials.On the other hand,developing an easy and green strategy to prepare functional materials with outstanding properties based on naturally abundant and environmentally friendly raw materials is highly desirable for sustainable development.Because biomass-derived materials are sustainable and biodegradable,they present a promising substitute for petroleum-based polymers.The three main structural constituents of the plant biomass-based materials that are naturally available are cellulose,hemicellulose,and lignin.This review details current developments using wood-based products such as cellulose,hemicellulose,and lignin in UV-shielding applications.It will start with assembling the structure and chemistry of cellulose,hemicellulose,and lignin,followed by their contributions to preparing UV-shielding materials.Finally,it will briefly discuss the different processing methods for the design of UV-shielding materials.The wood by-products offer additional opportunities to use the whole tree harvest. 展开更多
关键词 UV-SHIELDING wood cellulose LIGNIN HEMICELLULOSE sunlight protection
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Oxygen-assisted zinc recovery from electric arc furnace dust using magnesium chloride
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作者 Jingdong Huang Xiao Yang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第10期2300-2311,共12页
Electric arc furnace(EAF)dust is an important secondary resource containing metals,such as zinc(Zn)and iron(Fe).Recover-ing Zn from EAF dust can contribute to resource recycling and reduce environmental impacts.Howeve... Electric arc furnace(EAF)dust is an important secondary resource containing metals,such as zinc(Zn)and iron(Fe).Recover-ing Zn from EAF dust can contribute to resource recycling and reduce environmental impacts.However,the high chemical stability of ZnFe_(2)O_(4)in EAF dust poses challenges to Zn recovery.To address this issue,a facile approach that involves oxygen-assisted chlorination using molten MgCl_(2)is proposed.This work focused on elucidating the role of O2 in the reaction between ZnFe_(2)O_(4)and molten MgCl_(2).The results demonstrate that MgCl_(2)effectively broke down the ZnFe_(2)O_(4)structure,and the high O2 atmosphere considerably promoted the sep-aration of Zn from other components in the form of ZnCl_(2).The presence of O2 facilitated the formation of MgFe_(2)O_(4),which stabilized Fe and prevented its chlorination.Furthermore,the excessive use of MgCl_(2)resulted in increased evaporation loss,and high temperatures pro-moted the rapid separation of Zn.Building on these findings,we successfully extracted ZnCl_(2)-enriched volatiles from practical EAF dust through oxygen-assisted chlorination.Under optimized conditions,this method achieved exceptional Zn chlorination percentage of over 97%within a short period,while Fe chlorination remained below 1%.The resulting volatiles contained 85wt%of ZnCl_(2),which can be further processed to produce metallic Zn.The findings offer guidance for the selective recovery of valuable metals,particularly from solid wastes such as EAF dust. 展开更多
关键词 electric arc furnace dust ZINC OXYGEN magnesium chloride CHLORINATION
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Valorization of Tree Bark-Derived Suberin in Applications for the Bio-Based Composites Industry–A Recent Review
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作者 Aleksandra Jeżo 《Journal of Renewable Materials》 EI CAS 2024年第6期1029-1042,共14页
Bark extracts are sustainable sources of biopolymers and hold great promise for replacing fossil fuel-based polymers,for example,in wood-based composites.In addition to primary and secondary metabolites,tree bark also... Bark extracts are sustainable sources of biopolymers and hold great promise for replacing fossil fuel-based polymers,for example,in wood-based composites.In addition to primary and secondary metabolites,tree bark also contains suberin,which plays a major role in protecting the tree from environmental conditions.Suberin is a natural aliphatic-aromatic cross-linked polyester present in the cell walls of both normal and damaged external tissues,the main component of which are long-chain aliphatic acids.Its main role as a plant ingredient is to protect against microbiological factors and water loss.One of the most important suberin monomers are suberin fatty acids,known for their hydrophobic and barrier properties.Therefore,due to the diverse chemical composition of suberin,it is an attractive alternative to hydrocarbon-based materials.Although its potential is recognized,it is not widely used in biocomposites technology,including wood-based composites and the polymer industry.The article will discuss the current knowledge about the potential of suberin and its components in biocomposites technology,which will include surface finishes,composite adhesives and polymer blends. 展开更多
关键词 SUBERIN suberinic acids wood composites BIOCOMPOSITES biopolyester
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Global dust density in two-dimensional complex plasma
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作者 赵逸真 刘松芬 +1 位作者 孔伟 杨芳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期445-450,共6页
The driven-dissipative Langevin dynamics simulation is used to produce a two-dimensional(2D) dense cloud, which is composed of charged dust particles trapped in a quadratic potential. A 2D mesh grid is built to analyz... The driven-dissipative Langevin dynamics simulation is used to produce a two-dimensional(2D) dense cloud, which is composed of charged dust particles trapped in a quadratic potential. A 2D mesh grid is built to analyze the center-to-wall dust density. It is found that the local dust density in the outer region relative to that of the inner region is more nonuniform,being consistent with the feature of quadratic potential. The dependences of the global dust density on equilibrium temperature, particle size, confinement strength, and confinement shape are investigated. It is found that the particle size, the confinement strength, and the confinement shape strongly affect the global dust density, while the equilibrium temperature plays a minor effect on it. In the direction where there is a stronger confinement, the dust density gradient is bigger. 展开更多
关键词 dust particles quadratic potential two-dimensional mesh grid
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Climatic and Environmental Impacts of Dust over the Tibetan Plateau: An Overview
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作者 Ashok Kumar Pokharel Shree Pandey 《Journal of Environmental Protection》 2024年第9期907-920,共14页
The Tibetan Plateau (TP), located at a height of nearly 4000 m above sea level, has a unique setting that effects the environment of the whole of northern hemisphere. It acts as the “water reservoir” of Asia as seve... The Tibetan Plateau (TP), located at a height of nearly 4000 m above sea level, has a unique setting that effects the environment of the whole of northern hemisphere. It acts as the “water reservoir” of Asia as several important rivers originate from this region. Therefore, even slight alternations in the TP’s hydrological cycle may have profound ecological and social impacts. However, it is experiencing a significant increase in accumulation of dust from local and global sources. The impact of dust on the region’s climate has become an active area of research. Further, the study of sources of dust arriving at the TP is also critical. Accumulation of dust is impacting temperature, snow cover, glaciers, water resources, biodiversity and soil desertification. This manuscript tries to provide a comprehensive summary of the impact of dust on weather, climate, and environmental components of the TP. The impact of dust on clouds, radiative energy, precipitation, atmospheric circulation, snow and ice cover, soil, air quality, and river water quality of the TP are discussed. It further discusses the steps immediately needed to mitigate the devastating impact of dust on the fragile ecosystem of the TP. 展开更多
关键词 Tibetan Plateau dust CLOUDS Precipitation Radiative Forcing SNOW
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