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“Steric Armor”Strategy of Blue Fluorescent Emitters against Photooxidation-Induced Degradation

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Chinese Journal of Chemistry 2024年第11期42卷 1223-1229页

作者： Sha-Sha Wang Jing-Rui Zhang Kuan-De Wang hao-ran li Peng-Hui Meng Yang Zhou Xiang Yu Ying Wei Quan-You Feng Yu-He Kan ling-Hai Xie Centre for Molecular Systems and Organic Devices(CMSOD) State Key Laboratory of Organic Electronics and Information Displays&Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing University of Posts&TelecommunicationsNanjingJiangsu210023 China Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials School of Chemistry and Chemical EngineeringHuaiyin Normal UniversityHuai'anJiangsu223300 China

Stability against oxygen is an important factor affecting the performance of organic semiconductor *** photooxidation stability can prolong the service life of the device and maintain the mechanical and photoelectric properties of the ***,various encapsulation methods from molecular structure to macroscopic device level are used to improve photooxidation ***,we adopted a crystallization strategy to allow 14H-spiro[dibenzo[c,h]acridine-7,9′-fluorene](SFDBA)to pack tightly to resist fluorescence decay caused by *** this case,the inert group of SFDBA acts as a“steric armor”,protecting the photosensitive group from being attacked by ***,compared with the fluorescence quenching of SFDBA powder under 2 h of sunlight,SFDBA crystal can maintain its fluorescence emission for more than 8 h under the same ***,the photoluminescence quantum yields(PLQYs)of the crystalline film is 327%higher than that of the amorphous *** shows that the crystallization strategy is an effective method to resist oxidation.

关键词： Organic semiconductor Photooxidation Spirocyclic aromatic hydrocarbons Crystal engineering Fluorescence

锂离子电池正极材料原位漫反射光谱电化学研究

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电化学（中英文） 2024年第6期30卷 24-31页

作者：陈露露李浩冉刘维祎王伟生命分析化学国家重点实验室南京大学化学化工学院江苏南京210023

发展原位电化学光谱方法对深入研究电化学反应机理,并最终提高电池性能有着重要价值。建立在这一认识之上,能够应用于电池体系的原位光谱电化学表征技术被认为是表征电池电极材料性能的有效方法。但是受限于电池严格密封的不透明外壳和... 详细信息

发展原位电化学光谱方法对深入研究电化学反应机理,并最终提高电池性能有着重要价值。建立在这一认识之上,能够应用于电池体系的原位光谱电化学表征技术被认为是表征电池电极材料性能的有效方法。但是受限于电池严格密封的不透明外壳和当前商用电池体系严格隔绝水氧的客观要求,开发更贴近真实电池工作条件的原位光谱电化学表征技术仍有较大需求。基于此,本文设计了一种基于传统纽扣电池架构的原位电化学池,该装置通过特殊设计实现了在尽可能模拟电池工作环境的前提下拥有透明的上盖,从而使发生电化学反应的同时进行光学检测成为可能。利用这一电化学池,本文以锂离子电池中常用的正极材料liFePO_(4)(LFP)、NCM811和liCoO_(2)(LCO)为例,对其电化学反应过程中的漫反射光谱进行了采集和分析。相关数据定量地揭示了不同种类电极材料在一般反射光路架构下对不同波长可见光的响应关系,并能够直接用于对单色光检测场景下的波长优化提供指导和依据。更进一步,本文还对不同材料在充放电过程中的光谱特征进行了定量分析,揭示了其光谱特征同材料内在能级状态间的相关性。综上,本文提出了一种基于漫反射光谱的原位光谱电化学表征方法,作为对光谱电化学应用于电池体系的有效补充,本方法能够为评估电极材料性能提供一种全新且简单直接的途径,并最终助力电池性能的提升。

关键词：锂离子电池漫反射光谱电化学原位正极材料

Reductive leaching of manganese from low-grade pyrolusite ore in sulfuric acid using pyrolysis-pretreated sawdust as a reductant

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International Journal of Minerals,Metallurgy and Materials 2016年第3期23卷 241-246页

作者： Ya-li Feng Shi-yuan Zhang hao-ran li School of Civil and Environmental Engineering University of Science and Technology Beijing National Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences

Manganese （Mn） leaching and recovery from low-grade pyrolusite ore were studied using sulfiaric acid （H2SO4） as a leachant and pyrolysis-pretreated sawdust as a reductant. The effects of the dosage of pyrolysis-pretreated sawdust to pyrolusite ore, the concentration of sulfuric acid, the liquid/solid ratio, the leaching temperature, and the leaching time on manganese and iron leaching efficiencies were inves- tigated. Analysis of manganese and iron leaching efficiencies revealed that a high manganese leaching efficiency was achieved with low iron extraction. The optimal leaching efficiency was determined to be 20wt% pyrolysis-pretreated sawdust and 3.0 mol/L H2SO4 using a liq- uid/solid ratio of 6.0 mL/g for 90min at 90℃. Other low-grade pyrolusite ores were tested, and the results showed that they responded well with manganese leaching efficiencies greater than 98%.

关键词： manganese ore treatment pyrolusite sawdust pyrolysis leaching manganese

Corrected stress field intensity approach based on averaging superior limit of intrinsic damage dissipation work

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Journal of Iron and Steel Research International 2018年第10期25卷 1094-1103页

作者： hao-ran li Yan Peng Yang liu Ming Zhang National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University Qinhuangdao 066004 Hebei China

Corrected stress field intensity obtained by averaging the superior limit of intrinsic damage dissipation work in critical domain, which considers thoroughly thermodynamic consistency within irreversible thermodynamic framework, was proposed for predictions of high-cycle fatigue endurance limits. Simultaneously, the effects of mean stress, additional hardening behavior related to non-proportional loading paths and stress gradients on multiaxial high-cycle fatigue are taken into account in the proposed approach. The approach is an extension of the general stress field intensity. For a better comparison, existing multiaxial high-cycle fatigue criteria were employed to predict the endurance limits of different metallic materials subjected to different multiaxial loading paths, and it is shown that present proposal performs better from statistical value of error indexes, which make the proposed approach of corrected stress field intensity and its associated concepts provide a new conception to predict endurance limits of multiaxial high-cycle fatigue with high accuracy.

关键词： Intrinsic damage dissipation work Irreversible thermodynamic framework Corrected stress field intensity Multiaxial high-cycle fatigue Stress gradient

Dynamics of rolling mill drive system considering arc tooth gear dynamic characteristics

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Journal of Iron and Steel Research International 2019年第9期26卷 953-961页

作者： Ming Zhang Yan Peng Jian-liang Sun hao-ran li College of Mechanical and Equipment Engineering Hebei University of EngineeringHandan 056038HebeiChina National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004HebeiChina

The arc tooth gear spindle (ATGS) is the key structure of the drive system of hot finishing rolling mills. To investigate the dynamic characteristics of ATGS of the drive system of hot finishing rolling mills, a dynamic mechanical model of ATGS was established. The influences of dynamic displacement and dynamic torque on dynamic load (meshing force, additional torque and friction torque) were studied during the non-steady-state operation of ATGS. On this basis, a dynamic model of rolling mill drive system was established considering the arc tooth gear dynamic characteristics. The dynamic response of the drive system was simulated and analyzed. The results showed that the nonlinear characteristics of ATGS were obvious;the meshing force (PX and PZ) could restrain the increase in dynamic displacement, which reflected the positive stiffness of ATGS;there was a coupling among the vertical, horizontal and torsional directions in the drive system model considering the dynamic characteristics of the arc tooth gear;the vibration intensity of ATGS in the horizontal direction is greater than that in the vertical direction when the self-excited torsional vibration happens;the greater the axial inclination angle was, the more complex the vibration mode was, and the lower the stability of the drive system was.

关键词： Rolling mill Drive system Arc tooth gear Coupling model Dynamic characteristics

Reductive leaching of low-grade manganese ore with pre-processed cornstalk

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International Journal of Minerals,Metallurgy and Materials 2015年第12期22卷 1245-1251页

作者： Ai-fei Yi Meng-ni Wu Peng-wei liu Ya-li Feng hao-ran li School of Civil and Environment Engineering University of Science and Technology Beijing State Key Laboratory of High-Efficient Mining and Safety of Metal Mines (Ministry of Education) State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences

Cornstalk is usually directly used as a reductant in reduetive leaching manganese. However, low utilization of cornstalk makes low manganese dissolution ratio, In the research, pretreatment for cornstalk was proposed to improve manganese dissolution ratio. Cornstalk was preprocessed by a heated sulfuric acid solution （1.2 M of sulfuric acid concentration） for 10 min at 80℃. Thereafter, both the pretreated solution and the residue were used as a reductant for manganese leaching. This method not only exhibited superior activity for hydrolyzing cornstalk but also enhanced manganese dissolution. These effects were attributed to an increase in the amount of reductive sugars resulting from lignin hydrolysis. Through acid pretreatment for cornstalk, the manganese dissolution ratio was improved from 50.14% to 83.46%. The present work demonstrates for the first time the effective acid pretreatment of cornstalk to provide a cost-effective reductant for manganese leaching.

关键词： manganese ore treatment cornstalk reductants leaching

Fluidized roasting reduction kinetics of low-grade pyrolusite coupling with pretreatment of stone coal

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International Journal of Minerals,Metallurgy and Materials 2013年第3期20卷 221-227页

作者： Ya-li Feng Zhen-lei Cai hao-ran li Zhu-wei Du Xin-wei liu School of Civil and Environmental Engineering University of Science and Technology Beijing State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences

Based on the fluidized roasting reduction technology of low-grade pyrolusite coupling with pretreatment of stone coal, the manganese reduction efficiency was investigated and technical conditions were optimized. It is found that the optimum manganese reduction efficiency can be up to 98.97% under the conditions that the mass ratio of stone coal to pyrolusite is 3：1, the roasting temperature of stone coal is 1000℃, the roasting temperature of pyrolusite is 800℃, and the roasting time is 2 h. Other low-grade pyrolusite ores in China from Guangxi, Hunan, and Guizhou Provinces were tested and all these minerals responded well, giving -99% manganese reduction efficiency. Meanwhile, the reduction kinetic model has been established. It is confirmed that the reduction process is controlled by the interface chemical reaction. The apparent activation energy is 36.397 kJ/mol.

关键词： pyrolusite ore roasting ore reduction fluidized beds kinetics stone coal

A game-theoretic approach for federated learning:A trade-off among privacy,accuracy and energy

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Digital Communications and Networks 2024年第2期10卷 389-403页

作者： lihua Yin Sixin lin Zhe Sun ran li Yuanyuan He Zhiqiang hao Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhou510006China School of Cyber Science and Engineering Huazhong University of Science and TechnologyWuhan430074China China Industrial Control Systems Cyber Emergency Response Team Beijing100040China

Benefiting from the development of Federated Learning(FL)and distributed communication systems,large-scale intelligent applications become *** devices not only provide adequate training data,but also cause privacy leakage and energy *** to optimize the energy consumption in distributed communication systems,while ensuring the privacy of users and model accuracy,has become an urgent *** this paper,we define the FL as a 3-layer architecture including users,agents and *** order to find a balance among model training accuracy,privacy-preserving effect,and energy consumption,we design the training process of FL as game *** use an extensive game tree to analyze the key elements that influence the players’decisions in the single game,and then find the incentive mechanism that meet the social norms through the repeated *** experimental results show that the Nash equilibrium we obtained satisfies the laws of reality,and the proposed incentive mechanism can also promote users to submit high-quality data in *** the multiple rounds of play,the incentive mechanism can help all players find the optimal strategies for energy,privacy,and accuracy of FL in distributed communication systems.

关键词： Federated learning Privacy preservation Energy optimization Game theory Distributed communication systems

Impact of Annealing on the Melt Recrystallization of a-PDLA/α-PLLA Double-layered Films

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Chinese Journal of Polymer Science 2024年第2期42卷 230-238,I0009页

作者： Yun-Peng li hao-ran Shen Shao-Juan Wang hao Zhang Jian Hu Rui Xin Xiao-li Sun Shou-Ke Yan Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plasticsQingdao University of Science&TechnologyQingdao266042China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China

Poly(lactic acid)(PLA) as a bio-based polymer with biodegradability and biocompatibility has attracted much attention. To manipulate its properties for different applications, regulation of crystal structure and crystalline morphology becomes an attractive research topic. In this work, the structure evolution of layered samples containing an amorphous poly(D-lactide)(PDLA) layer and a crystalline poly(L-lactide)(PLLA)layer with highly oriented edge-on α lamellar crystals after annealing at 150 ℃ or/and after melt-recrystallization has been studied by AFM, FTIR,and TEM combined with electron diffraction. The results demonstrate that melt recrystallization of the as-prepared sample leads to the formation of abundant randomly oriented PLA stereo-complex(PLA SC) crystals. Annealing at 150 ℃ results in the formation of a small amount of oriented PLA SC crystals at the interface. These PLA SC crystals show great impact on the recrystallization behavior of sample after melting at 190 ℃ and then crystallizing at 90 ℃. First, they impede the mutual diffusion of the overlying PDLA and underlying PLLA, and thus reduce their stereocomplexation ability as manifested by the decreased amount of PLA SC crystals. Second, they act as substrate to initiate the epitaxial crystallization of the overlying PDLA and underlying PLLA, which ensures the production of a highly oriented structure of PDLA and PLLA after melt recrystallization again.

关键词： Poly(L-lactide) Poly(D-lactide) Double layer Stereocomplex