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Synthesis,structures,and properties of metal-organic frameworks based on bipyridyl ligands and isophthalic acid
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作者 HOU Jimin LI Mengyang +4 位作者 GONG Chunhua ZHANG Shaozhuang ZHAN Caihong XU Hao XIE Jingli 《无机化学学报》 北大核心 2025年第3期549-560,共12页
(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under... (2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4. 展开更多
关键词 bipyridyl ligands metal⁃organic frameworks photocatalytic degradation Knoevenagel condensation
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A CNT Intercalated Co Porphyrin-Based Metal Organic Framework Catalyst for Oxygen Reduction Reaction
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作者 Pei-Pei He Jin-Hua Shi +6 位作者 Xiao-Yu Li Ming-Jie Liu Zhou Fang Jing He Zhong-Jian Li Xin-Sheng Peng Qing-Gang He 《电化学(中英文)》 北大核心 2025年第1期31-40,共10页
The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNT... The poor electronic conductivity of metal-organic framework(MOF)materials hinders their direct application in the field of electrocatalysis in fuel cells.Herein,we proposed a strategy of embedding carbon nanotubes(CNTs)during the growth process of MOF crystals,synthesizing a metalloporphyrin-based MOF catalyst TCPPCo-MOF-CNT with a unique CNT-intercalated MOF structure.Physical characterization revealed that the CNTs enhance the overall conductivity while retaining the original characteristics of the MOF and metalloporphyrin.Simultaneously,the insertion of CNTs generated adequate mesopores and created a hierarchical porous structure that enhances mass transfer efficiency.X-ray photoelectron spectroscopic analysis confirmed that the C atom in CNT changed the electron cloud density on the catalytic active center Co,optimizing the electronic structure.Consequently,the E_(1/2) of the TCPPCo-MOF-CNT catalyst under neutral conditions reached 0.77 V(vs.RHE),outperforming the catalyst without CNTs.When the TCPPCo-MOF-CNT was employed as the cathode catalyst in assembling microbial fuel cells(MFCs)with Nafion-117 as the proton exchange membrane,the maxi-mum power density of MFCs reached approximately 500 mW·m^(-2). 展开更多
关键词 Metal organic framework CNT intercalated ELECTROCATALYSIS Oxygen reduction reaction Microbial fuel cell
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Metal-organic framework-derived sulfur-doped iron-cobalt tannate nanorods for efficient oxygen evolution reaction performance
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作者 ZHAI Haoying WEN Lanzong +3 位作者 LIAO Wenjie LI Qin ZHOU Wenjun CAO Kun 《无机化学学报》 北大核心 2025年第5期1037-1048,共12页
Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nano... Sulfur-doped iron-cobalt tannate nanorods(S-FeCoTA)derived from metal-organic frameworks(MOFs)as electrocatalysts were synthesized via a one-step hydrothermal method.The optimized S-FeCoTA was interlaced by loose nanorods,which had many voids.The S-FeCoTA catalysts exhibited excellent electrochemical oxygen evolution reaction(OER)performance with a low overpotential of 273 mV at 10 mA·cm^(-2)and a small Tafel slope of 36 mV·dec^(-1)in 1 mol·L^(-1)KOH.The potential remained at 1.48 V(vs RHE)at 10 mA·cm^(-2)under continuous testing for 15 h,implying that S-FeCoTA had good stability.The Faraday efficiency of S-FeCoTA was 94%.The outstanding OER activity of S-FeCoTA is attributed to the synergistic effects among S,Fe,and Co,thus promoting electron transfer,reducing the reaction kinetic barrier,and enhancing the OER performance. 展开更多
关键词 hydrothermal method tannic acid metal‑organic framework ELECTROCATALYSIS oxygen evolution reaction
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A review on dissolved organic matter derived from biochar in soil:Characterizations,interaction with pollutants,and transformation
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作者 ZHANG Xiu-xiu NAN Hong-yan +2 位作者 LIU Gong-gang SHOW Pau-Loke WANG Chong-qing 《Journal of Central South University》 2025年第1期122-148,共27页
Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influenc... Biochar-derived dissolved organic matter(BCDOM),an essential component of biochar,plays a vital role in regulating the physicochemical and biological properties of soils during biochar application.However,the influence of BCDOM on soil organisms has not been clearly explained.Hence,this review aims to discuss the factors affecting BCDOM and its interaction with soil substances including organic pollutants,heavy metals,and microorganisms.Results displayed that the quantity of BCDOM ranges from 0.17 to 37.03 mg/g,which was influenced by feedstock,preparation methods of biochar,and extraction methods.With the decrease in lignin content of feedstocks,carbonization temperature,and acidity of extraction solution,the content of BCDOM increased.Through complexation and adsorption,protein-like components in BCDOM interact with heavy metals,promoting the adsorption and immobilization of heavy metals onto biochar.Furthermore,BCDOM enhances the adsorption of organic pollutants by biochar throughπ−πinteractions,hydrogen bonding,and redox processes.More importantly,BCDOM promotes plant growth by enhancing microbial activities,providing nutrients,and improving soil properties.However,the transport and fate of BCDOM in soil have not been well studied,and more researches are needed to explore the interaction mechanisms between BCDOM and soil organisms. 展开更多
关键词 BIOCHAR dissolved organic matter heavy metals organic contaminants SOIL
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Visible to near-infrared photodetector based on organic semiconductor single crystal
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作者 LI Xiang HU Jin-Han +7 位作者 ZHONG Zhi-Peng CHEN Yu-Zhong WANG Zhi-Qiang SONG Miao-Miao WANG Yang ZHANG Lei LI Jian-Feng HUANG Hai 《红外与毫米波学报》 北大核心 2025年第1期46-51,共6页
Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application ... Organic semiconductor materials have shown unique advantages in the development of optoelectronic devices due to their ease of preparation,low cost,lightweight,and flexibility.In this work,we explored the application of the organic semiconductor Y6-1O single crystal in photodetection devices.Firstly,Y6-1O single crystal material was prepared on a silicon substrate using solution droplet casting method.The optical properties of Y6-1O material were characterized by polarized optical microscopy,fluorescence spectroscopy,etc.,confirming its highly single crystalline performance and emission properties in the near-infrared region.Phototransistors based on Y6-1O materials with different thicknesses were then fabricated and tested.It was found that the devices exhibited good visible to near-infrared photoresponse,with the maximum photoresponse in the near-infrared region at 785 nm.The photocurrent on/off ratio reaches 10^(2),and photoresponsivity reaches 16 mA/W.It was also found that the spectral response of the device could be regulated by gate voltage as well as the material thickness,providing important conditions for optimizing the performance of near-infrared photodetectors.This study not only demonstrates the excellent performance of organic phototransistors based on Y6-1O single crystal material in near-infrared detection but also provides new ideas and directions for the future development of infrared detectors. 展开更多
关键词 near-infrared photodetector organic semiconductor Y6-1O single crystal spectral response
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Effects of Lignite and Biochar on Enzyme Activity and Organic Carbon in Zn-contaminated Black Soil
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作者 Dai Jianjun Liu Zhaoting +1 位作者 Su Dezhen Wang Jingyi 《Journal of Northeast Agricultural University(English Edition)》 2025年第2期23-36,共14页
In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon ... In order to explore the remediation effects of lignite and biochar on Zn-contaminated soil,this experiment studied the impacts of adding lignite and biochar on soil respiration,soil enzyme activity,and organic carbon in Zn-contaminated soil through soil culture experiments,which provided a theoretical basis for the remediation and improvement as well as for the development and utilization of Zn-contaminated soil.The study was an L8(4×2^(2))orthogonal experimental design with eight treatments,in which there were four levels of Zn contamination concentration(Z0:0;Z1:125 mg•kg^(-1);Z2:250 mg•kg^(-1);Z3:500 mg•kg^(-1)),low-Zn(125-250 mg•kg^(-1))and high-Zn(500 mg•kg^(-1)),two levels of lignite(H0:0;H1:13.33 g•kg^(-1)),two levels of biochar(C0:0;C1:3.33 g•kg^(-1)),with four replicates per treatment.The results showed that lignite or biochar and their interaction had extremely significant effects on both respiration rate and accumulation in Zn-contaminated soil.Among the high Zn-contaminated treatments,the mixed application of lignite and biochar(Z3H1C1 treatment)had the fastest soil respiration rate and the highest soil respiration accumulation.Lignite,biochar and their interaction had significant or extremely significant effects on sucrase,catalase and polyphenol oxidase activities in Zn-contaminated soil.Among the high Zn-contaminated treatments(Z3),the addition of biochar alone had the most significant effects on the increase of soil sucrase and catalase enzyme activities,while the mixed application of lignite and biochar had the most significant effects on the increase of soil polyphenol oxidase activity.Lignite,biochar and their interaction had significant or extremely significant effects on the total organic carbon,active organic carbon and microbial carbon content of Zn-contaminated soils.Soil total organic carbon content in general peaked at day 80.Among the high Zn-contaminated treatments,the addition of biochar alone had the most significant effects on the total organic carbon content of the soil,while the mixed application of lignite and biochar had the most significant effect on the microbiomass carbon content. 展开更多
关键词 Zn pollution LIGNITE BIOCHAR enzyme activity organic carbon
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Key Physical Factors Affecting Spatial-temporal Variation of Labile Organic Carbon Fractions by Biochar Driven in Mollisols Region of Northeast China
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作者 Zhao Wei Liang Fangyuan +4 位作者 Liang Ying Zhao Hongrui Hao Shuai Wang Hongyan Wang Daqing 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第1期28-41,共14页
Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between phy... Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between physical properties and LOC fractions. A field positioning experiment was performed in Mollisols region of Northeast China to evaluate the influence of maize stalk biochar on the spatial distribution and temporal changes of physical properties and LOC fractions. Maize stalk biochar treatments included C1(1.5 kg·hm^(-2)), C2(3 kg·hm^(-2)), C3(15 kg·hm^(-2)), C4(30 kg·hm^(-2)), and CK(0). The results showed that maize stalk biochar increased soil water contents(SWC) and soil porosity(SP), but reduced bulk density(BD). Maize stalk biochar reduced dissolved organic carbon(DOC) contents in the 0-20 cm soil layer, ranging from 0.25 g·kg^(-1) to 0.31 g·kg^(-1) in harvest period, while increased in the 20-40 cm soil layer. In addition, the application of biochar had a significant impact on the spatial distribution and temporal change of SWC, BD, SP, DOC, hot-water extractable carbon(HWC), acid hydrolyzed organic carbon(AHC Ⅰ, Ⅱ), and readily oxidized organic carbon(ROC). High amounts of maize stalk biochar up-regulated the contents of soil organic carbon SOC, HWC, AHC Ⅰ, AHC Ⅱ, and ROC. In addition, SWC and SP were the key physical factors to affect LOC fractions. In conclusions, maize stalk biochar could improve physical properties, and then influence LOC fractions, and maize stalk biochar could be used as an organic amendment for restoring degraded soils governed by their rates of addition. 展开更多
关键词 maize stalk biochar labile organic carbon fraction Mollisols region soil physical property dissolved organic carbon
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Effects of Biochar and Soil Organic Matter Levels on Physicochemical Properties of Mollisol and Soybean's Biomass
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作者 Zhang Shuaikun Xu Zhiyuan +4 位作者 Shi Fangfang Yang Jing Luo Xu Jiang Zhenfeng Liu Zhihua 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第3期33-41,共9页
Long term tillage in mollisol of Northeast China has led to an inhomogeneous distribution of soil organic matter content.Biochar,a carbon material,changes the soil carbon pool and physical-chemical characteristics aft... Long term tillage in mollisol of Northeast China has led to an inhomogeneous distribution of soil organic matter content.Biochar,a carbon material,changes the soil carbon pool and physical-chemical characteristics after adding to the soil.However,the mechanism remains unclear for the relation between the soil organic matter level and biochar amount.So,the soil physical and chemical properties and soybean growth in a two-year pot experiment were detected at three levels of soil organic matter and three biochar additions(0,1%and 10%).The difference was found in two biochar application rates.The 1%biochar addition had no positive effect on the soil chemical properties based the two-year experiment.However,10%biochar application significantly increased the soil water content(8.0%-39.7%),the total porosity(9.7%-21.3%),pH(0.26-0.84 unit),organic matter content(89.0%-261.2%),and the available potassium content(29.0%-109.1%).The biomass of soybean increased by 19.4%-78.1%after biochar addition,yet,the soil bulk density reduced at the range of 12.6%-26.0%by 10%biochar addition.Only the 100-grain weight was correlated to the interaction of biochar and the native soil organic matter.All the indicators showed that the interaction between biochar and soil organic matter level was weak in mollisol.The effects of biochar on the physical-chemical properties relied on its amount.When biochar is applied to the soil,the amount of biochar should be considered rather than the native soil organic matter level. 展开更多
关键词 BIOCHAR soil organic matter bulk density available nutrient
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基于24Model的动火作业事故致因文本挖掘
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作者 牛茂辉 李威君 +1 位作者 刘音 王璐 《中国安全科学学报》 北大核心 2025年第3期151-158,共8页
为探究工业动火作业事故的根源,提出一种基于“2-4”模型(24Model)的文本挖掘方法。首先,收集整理220篇动火作业事故报告,并作为数据集,构建基于来自变换器的双向编码器表征量(BERT)的24Model分类器,使用预训练模型训练和评估事故报告... 为探究工业动火作业事故的根源,提出一种基于“2-4”模型(24Model)的文本挖掘方法。首先,收集整理220篇动火作业事故报告,并作为数据集,构建基于来自变换器的双向编码器表征量(BERT)的24Model分类器,使用预训练模型训练和评估事故报告数据集,构建分类模型;然后,通过基于BERT的关键字提取算法(KeyBERT)和词频-逆文档频率(TF-IDF)算法的组合权重,结合24Model框架,建立动火作业事故文本关键词指标体系;最后,通过文本挖掘关键词之间的网络共现关系,分析得到事故致因之间的相互关联。结果显示,基于BERT的24Model分类器模型能够系统准确地判定动火作业事故致因类别,通过组合权重筛选得到4个层级关键词指标体系,其中安全管理体系的权重最大,结合共现网络分析得到动火作业事故的7项关键致因。 展开更多
关键词 “2-4”模型(24model) 动火作业 事故致因 文本挖掘 指标体系
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Effects of Biochar-based Organic Fertilizer on Accumulation of Total Flavonoid Contents in Dandelion
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作者 Jiang Xinmei Zhang Yuxin +4 位作者 Liu Hanbing Cheng Yao Liu Xiubo Liu Weili Ma Wei 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第4期46-53,共8页
In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic ... In order to study the effects of biochar-based organic fertilizer on the accumulation of the total flavonoid contents in dandelion after sowing,the experiment applied four levels of treatments of carbon-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),and the base fertilizer that only applied conventional chemical fertilizer was used as the control.The total flavonoid contents and physiological indices of dandelion in different growth periods were determined.The results showed that the accumulation of the total flavonoid contents in leaves and roots of dandelion improved significantly by applying biochar-based organic fertilizer(0.15,0.30,0.45,and 0.60 kg•m^(-2)),with the highest total flavonoid occurred in the 0.45 kg•m^(-2) biochar-based organic fertilizer treatment.Along with dandelion growing,the total flavonoid contents in leaves were first elevated,and then decreased,with the maximum reached at 95 days after sowing(anthesis).While the total flavonoid contents in roots were elevated constantly.The total flavonoid contents accumulation in dandelion were positively correlated with net photosynthetic rate,stomatal conductance,transpiration rate,soluble sugar content,soluble protein,nitrate nitrogen,and available potassium,while negatively correlated with intercellular CO_(2) concentration. 展开更多
关键词 DANDELION total flavonoid contents biochar-based organic fertilizer photosynthesis soil nutrient
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Effect of organic carbon sources on the anodic corrosion of magnesium AZ31B by sulfate-reducing prokaryote
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作者 LI Jin-rong ZHANG Jie +6 位作者 KRISHNAMURTHY Mathivanan ZHU Qing-jun XING Shao-hua ZHANG Rui-yong SAND Wolfgang DUAN Ji-zhou HOU Bao-rong 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第10期3369-3381,共13页
Corrosion caused by sulfate-reducing prokaryotes(SRP)is an important cause of magnesium alloy anode failure in oil pipeline.In this study,the effects of Desulfovibrio sp.HQM3 on the corrosion behavior of AZ31B magnesi... Corrosion caused by sulfate-reducing prokaryotes(SRP)is an important cause of magnesium alloy anode failure in oil pipeline.In this study,the effects of Desulfovibrio sp.HQM3 on the corrosion behavior of AZ31B magnesium alloy anode in organic carbon sources with different contents in simulated tidal flat environment were analyzed using weight loss test,surface analysis and electrochemical analysis technologies.The results showed that the weight loss rate of coupons in low carbon sources contents(0%,1%,10%)was higher than that in 100%carbon sources.Electrochemical analyses showed that the corrosion current density(J_(corr))under low carbon sources contents was larger,while the charge transfer resistance(R_(ct))was lower,leading to a higher corrosion rate compared to those under 100%carbon sources content.Observations from scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM)revealed more severe pitting corrosion on the alloy surface in the absence of carbon sources.In addition,a large number of nanowires were observed between bacteria on the alloy surface using SEM.Combined with thermodynamic calculations,it was demonstrated that the corrosion of coupons by Desulfovibrio sp.HQM3 in the absence of carbon sources was achieved through extracellular electron transfer. 展开更多
关键词 AZ31B magnesium anode organic carbon source microbiologically influenced corrosion(MIC) sulfatereducing prokaryotes
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High-speed doctor-blading PM 6:L 8-BO organic solar cells from non-halogenated green solvent with a module efficiency of 16.07%
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作者 FENG Er-ming ZHANG Chu-jun +8 位作者 HAN Yun-fei CHANG Jian-hui YANG Fang LI Heng-yue LUO Qun MA Chang-qi ZOU Ying-ping DING Li-ming YANG Jun-liang 《Journal of Central South University》 CSCD 2024年第12期4297-4306,共10页
Highly efficient organic solar cells(OSCs)are normally produced using the halogenated solvents chloroform or chlorobenzene,which present challenges for scalable manufacturing due to their toxicity,narrow processing wi... Highly efficient organic solar cells(OSCs)are normally produced using the halogenated solvents chloroform or chlorobenzene,which present challenges for scalable manufacturing due to their toxicity,narrow processing window and low boiling point.Herein,we develop a novel high-speed doctor-blading technique that significantly reduces the required concentration,facilitating the use of eco-friendly,non-halogenated solvents as alternatives to chloroform or chlorobenzene.By utilizing two widely used high-boiling,non-halogenated green solvents-o-xylene(o-XY)and toluene(Tol)-in the fabrication of PM 6:L 8-BO,we achieve power conversion efficiencies(PCEs)of 18.20%and 17.36%,respectively.Additionally,a module fabricated with o-XY demonstrates a notable PCE of 16.07%.In-situ testing and morphological analysis reveal that the o-XY coating process extends the liquid-to-solid transition stage to 6 s,significantly longer than the 1.7 s observed with Tol processing.This prolonged transition phase is crucial for improving the crystallinity of the thin film,reducing defect-mediated recombination,and enhancing carrier mobility,which collectively contribute to superior PCEs. 展开更多
关键词 organic solar module high-speed doctor-blading non-halogenated solvent green solvent
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Prolonging charge carrier lifetime via reinforcing molecular stacking for high-efficiency organic solar cells
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作者 BAI Ya-hui WANG Ke +5 位作者 WU Xiang-xi HE Dan LI Xiao-jun ZHANG Jian-qi LI Yong-fang ZHAO Fu-wen 《Journal of Central South University》 CSCD 2024年第12期4307-4318,共12页
Limited charge carrier lifetime(τ)leads to the short charge carrier diffusion length(L_(D))and thus impedes the improvement of power conversion efficiencies(PCEs)of organic solar cells(OSCs).Herein,anthracene(AN)as t... Limited charge carrier lifetime(τ)leads to the short charge carrier diffusion length(L_(D))and thus impedes the improvement of power conversion efficiencies(PCEs)of organic solar cells(OSCs).Herein,anthracene(AN)as the additive is introduced into classical donor:acceptor pairs to increase theτ.Introducing AN efficiently enhances the crystallinity of the PM 6:BTP-eC 9+blend film to reduce the trap density and increase theτto 1.484μs,achieving the prolonged L_(D).The prolonged L_(D) enables the PM 6:BTP-eC 9+blend film to gain weaker charge carrier recombination,reduced leakage current,and shorter charge carrier extraction time in devices,compared with PM 6:BTP-eC 9 counterparts.Therefore,PM 6:BTP-eC 9+based OSCs achieve higher PCEs of 18.41%±0.16%than PM 6:BTP-eC 9 based ones(17.08%±0.11%).Moreover,the PM 6:L 8-BO+based OSC presents an impressive PCE of 19.14%.It demonstrates that introducing AN is an efficient method to increase theτfor prolonged L_(D),boosting PCEs of OSCs. 展开更多
关键词 charge carrier diffusion length charge carrier lifetime molecular stacking organic solar cells
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Evaluation of working fluids for organic Rankine cycles using group-contribution methods and second-law-based models 被引量:1
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作者 MA Wei-wu WANG Lin +1 位作者 LIU Tao LI Min 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第8期2234-2243,共10页
The group-contribution (GC) methods suffer from a limitation concerning to the prediction of process-related indexes, e.g., thermal efficiency. Recently developed analytical models for thermal efficiency of organic Ra... The group-contribution (GC) methods suffer from a limitation concerning to the prediction of process-related indexes, e.g., thermal efficiency. Recently developed analytical models for thermal efficiency of organic Rankine cycles (ORCs) provide a possibility of overcoming the limitation of the GC methods because these models formulate thermal efficiency as functions of key thermal properties. Using these analytical relations together with GC methods, more than 60 organic fluids are screened for medium-low temperature ORCs. The results indicate that the GC methods can estimate thermal properties with acceptable accuracy (mean relative errors are 4.45%-11.50%);the precision, however, is low because the relative errors can vary from less than 0.1% to 45.0%. By contrast, the GC-based estimation of thermal efficiency has better accuracy and precision. The relative errors in thermal efficiency have an arithmetic mean of about 2.9% and fall within the range of 0-24.0%. These findings suggest that the analytical equations provide not only a direct way of estimating thermal efficiency but an accurate and precise approach to evaluating working fluids and guiding computer-aided molecular design of new fluids for ORCs using GC methods. 展开更多
关键词 organic Rankine cycles (ORCs) group contribution methods working fluids property estimation computer-aided molecular design
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Comparative study on the oblique water-entry of high-speed projectile based on rigid-body and elastic-plastic body model 被引量:1
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作者 Xiangyan Liu Xiaowei Cai +3 位作者 Zhengui Huang Yu Hou Jian Qin Zhihua Chen 《Defence Technology(防务技术)》 2025年第4期133-155,共23页
To examine the similarities and differences in the evolution of cavity,wetting and dynamics of a highspeed,oblique water-entry projectile with different positive angles of attack,a comparative analysis has been conduc... To examine the similarities and differences in the evolution of cavity,wetting and dynamics of a highspeed,oblique water-entry projectile with different positive angles of attack,a comparative analysis has been conducted based on the numerical results of two mathematical models,the rigid-body model and fluid-structure interaction model.In addition,the applicable scope of the above two methods,and the structural response characteristics of the projectile have also been investigated.Our results demonstrate that:(1) The impact loads and angular motion of the projectile of the rigid-body method are more likely to exhibit periodic variations due to the periodic tail slap,its range of positive angles of attack is about α<2°.(2) When the projectile undergone significant wetting,a strong coupling effect is observed among wetting,structural deformation,and projectile motion.With the applied projectile shape,it is observed that,when the projectile bends,the final wetting position is that of Part B(cylinder of body).With the occu rrence of this phenomenon,the projectile ballistics beco me completely unstable.(3) The force exerted on the lower surface of the projectile induced by wetting is the primary reason of the destabilization of the projectile traj ectory and structu ral deformation failure.Bending deformation is most likely to appear at the junction of Part C(cone of body) and Part D(tail).The safe angles of attack of the projectile stability are found to be about α≤2°. 展开更多
关键词 Fluid-structure interaction Rigid-body model Elastic-plastic model Structural deformation Impact loads Structural safety of projectile
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Vertical phase separation and morphology optimization of layer-by-layer non-fullerene organic solar cells
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作者 NING Bo-cheng MA Yu-meng +4 位作者 ZHANG Jun ZOU Ying-ping YANG Jun-liang YUAN Yong-bo ZHANG Lin 《Journal of Central South University》 CSCD 2024年第12期4338-4365,共28页
The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricatin... The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricating high-performance and large-area organic solar cells(OSCs).This method allows for the independent dissolution and deposition of donor and acceptor materials,enabling precise morphology control.In this review,we provide a comprehensive overview of the LBL processing technique,focusing on the morphology of the active layer.The swelling intercalation phase-separation(SIPS)model is introduced as the mainstream theory of morphology evolution,with a detailed discussion on vertical phase separation.We summarize recent strategies for morphology optimization.Additionally,we review the progress in LBL-based large-area device and module fabrication,as well as green processing approaches.Finally,we highlight current challenges and future prospects,paving the way for the commercialization of LBL-processed OSCs. 展开更多
关键词 organic solar cells layer-by-layer(LBL)solution processing technique vertical phase separation morphology optimization non-fullerene acceptors
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Solubility and Thermodynamic Modeling of 3⁃Nitro⁃1,2,4⁃triazole⁃5⁃one(NTO)in Different Binary Solvents 被引量:1
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作者 GUO Hao-qi YANG Yu-lin 《含能材料》 北大核心 2025年第3期295-303,共9页
Using a dynamic laser monitoring technique,the solubility of 3-nitro-1,2,4-triazole-5-one(NTO)was investigated in two different binary systems,namely hydroxylamine nitrate(HAN)-water and boric acid(HB)-water ranging f... Using a dynamic laser monitoring technique,the solubility of 3-nitro-1,2,4-triazole-5-one(NTO)was investigated in two different binary systems,namely hydroxylamine nitrate(HAN)-water and boric acid(HB)-water ranging from 278.15 K to 318.15 K.The solubility in each system was found to be positively correlated with temperature.Furthermore,solubility data were analyzed using four equations:the modified Apelblat equation,Van’t Hoff equation,λh equation and CNIBS/R-K equations,and they provided satisfactory results for both two systems.The average root-mean-square deviation(105RMSD)values for these models were less than 13.93.Calculations utilizing the Van’t Hoff equation and Gibbs equations facilitated the derivation of apparent thermodynamic properties of NTO dissolution in the two systems,including values for Gibbs free energy,enthalpy and entropy.The%ζ_(H)is larger than%ζ_(TS),and all the%ζ_(H)data are≥58.63%,indicating that the enthalpy make a greater contribution than entropy to theΔG_(soln)^(Θ). 展开更多
关键词 3-nitro-l 2 4-triazole-5-one(NTO) SOLUBILITY thermodynamic models apparent thermodynamic analysis
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Investigation on the Ice Load on a Cylinder Vertically Breaking through Model Ice Sheet from Underneath
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作者 ZHAO Wei−hang TIAN Yu−kui +3 位作者 JI Shao−peng GANG Xu−hao YU Chao−ge KONG Shuai 《船舶力学》 北大核心 2025年第6期964-975,共12页
Ice load on underwater vehicles breaking through ice covers from underneath is a significant concern for researchers in polar exploration,and the research on this problem is still in its early stages.Both mechanical e... Ice load on underwater vehicles breaking through ice covers from underneath is a significant concern for researchers in polar exploration,and the research on this problem is still in its early stages.Both mechanical experimental measurement and numerical simulation pose research challenges.This study focuses on the ice load of a cylinder structure breaking upward through the ice sheet form underneath in the Small Ice Model Basin of China Ship Scientific Research Center(CSSRC SIMB).A high-speed camera system was employed to observe the ice sheet failure during the tests,in which,with the loading position as center,local radial cracks and circumferential cracks were generated.A load sensor was used to measure the overall ice load during this process.Meanwhile,a numerical model was developed using LS-DYNA for validation and comparison.With this model,numerical simulation was conducted under various ice thicknesses and upgoing speeds to analyze the instantaneous curves of ice load.The calculation results were statistically analyzed under different working conditions to determine the influence of the factors on the ice load of the cylinder.The study explores the measurement method about ice load of objects vertically breaking through model ice sheet and is expected to provide some fundamental insights into the safety design of underwater structures operating in ice waters. 展开更多
关键词 CYLINDER model test failure mode crack propagation ice load numerical modeling
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Dynamics of a Stochastic Epidemic Model with Age-group
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作者 LAN Xiaomin CHEN Guangmin +5 位作者 ZHOU Ruiyang ZHENG Kuicheng CAI Shaojian WEI Fengying JIN Zhen MAO Xuerong 《应用数学》 北大核心 2025年第1期294-307,共14页
A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,t... A stochastic epidemic model with two age groups is established in this study,in which the susceptible(S),the exposed(E),the infected(I),the hospitalized(H)and the recovered(R)are involved within the total population,the aging rates between two age groups are set to be constant.The existence-and-uniqueness of global positive solution is firstly showed.Then,by constructing several appropriate Lyapunov functions and using the high-dimensional Itô’s formula,the sufficient conditions for the stochastic extinction and stochastic persistence of the exposed individuals and the infected individuals are obtained.The stochastic extinction indicator and the stochastic persistence indicator are less-valued expressions compared with the basic reproduction number.Meanwhile,the main results of this study are modified into multi-age groups.Furthermore,by using the surveillance data for Fujian Provincial Center for Disease Control and Prevention,Fuzhou COVID-19 epidemic is chosen to carry out the numerical simulations,which show that the age group of the population plays the vital role when studying infectious diseases. 展开更多
关键词 Epidemic model Age groups PERSISTENCE EXTINCTION
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Modeling and sliding mode control based on inverse compensation of piezo-positioning system
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作者 LI Zhi-bin XIN Yuan-ze +1 位作者 ZHANG Jian-qiang SUN Chong-shang 《中国光学(中英文)》 北大核心 2025年第1期170-185,共16页
In order to enhance the control performance of piezo-positioning system,the influence of hysteresis characteristics and its compensation method are studied.Hammerstein model is used to represent the dynamic hysteresis... In order to enhance the control performance of piezo-positioning system,the influence of hysteresis characteristics and its compensation method are studied.Hammerstein model is used to represent the dynamic hysteresis nonlinear characteristics of piezo-positioning actuator.The static nonlinear part and dynamic linear part of the Hammerstein model are represented by models obtained through the Prandtl-Ishlinskii(PI)model and Hankel matrix system identification method,respectively.This model demonstrates good generalization capability for typical input frequencies below 200 Hz.A sliding mode inverse compensation tracking control strategy based on P-I inverse model and integral augmentation is proposed.Experimental results show that compared with PID inverse compensation control and sliding mode control without inverse compensation,the sliding mode inverse compensation control has a more ideal step response and no overshoot,moreover,the settling time is only 6.2 ms.In the frequency domain,the system closed-loop tracking bandwidth reaches 119.9 Hz,and the disturbance rejection bandwidth reaches 86.2 Hz.The proposed control strategy can effectively compensate the hysteresis nonlinearity,and improve the tracking accuracy and antidisturbance capability of piezo-positioning system. 展开更多
关键词 piezo-positioning system hysteresis nonlinearity Hammerstein model Prandtl-Ishlinskii(P-I)model system identification sliding mode control
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