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煤基新材料——煤基石墨烯的制备及石墨烯在导热领域应用研究进展

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煤炭学报 2020年第1期45卷 443-454页

作者：闫云飞高伟杨仲卿张力冉景煜重庆大学低品位能源利用技术及系统教育部重点实验室

以石墨烯等为代表的具有优良物性和高附加值的新型材料得到越来越广泛的研究和应用,煤作为一种低价的高碳资源可通过不同的物理或化学方法制备成石墨烯及其化合物,使煤炭达到清洁高效利用,形成高附加值的煤基新材料。本文首先对石墨烯... 详细信息

以石墨烯等为代表的具有优良物性和高附加值的新型材料得到越来越广泛的研究和应用,煤作为一种低价的高碳资源可通过不同的物理或化学方法制备成石墨烯及其化合物,使煤炭达到清洁高效利用,形成高附加值的煤基新材料。本文首先对石墨烯的制备方法进行综述进而引出煤基石墨烯的制备方法。煤基石墨烯是以煤炭为原料转化而成的石墨烯,通过高温热处理后,采用常规石墨烯的制备方法获取煤基石墨烯。随后对石墨烯具有超高的导热性能机理进行分析。随着电子工业的快速发展,越来越多的高性能电子产品面临越来越大的散热困境。石墨烯的导热系数是目前已知材料中最高的,远超常规金属。利用石墨烯具有超高的横向导热机理,其单质或化合物可作为电子元器件理想的散热材料,逐渐取代传统金属导热材料,应用前景广阔。再分别对少数层石墨烯、石墨烯的复合材料、氧化石墨烯的复合材料在导热领域方面的研究进展及性能表现进行综述。其中石墨烯的复合材料的导热能力更强,应用范围更广。借助外力使石墨烯纳米片取向与传热方向对齐,可极大提高石墨烯复合材料导热能力。为进一步扩大石墨烯的应用范围、增强石墨烯平面外导热能力,可将石墨烯与碳纳米管结合。最后对煤基石墨烯的制备及石墨烯在导热领域的研究方向及发展前景进行了展望。

关键词：煤基石墨烯制备强化传热导热能力

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活性炭纤维脱除二氧化碳的实验研究

环境工程学报 2010年第1期4卷 169-172页

作者：胡林冉景煜张力唐强重庆大学动力工程学院重庆400044

采用活性炭纤维(ACF)作为吸附材料,研究了ACF对CO_2和N_2的吸、脱分离特性。结果表明,粘胶基活性炭纤维(V-ACF)和聚丙烯腈基活性炭纤维(PAN-ACF)对CO_2和N_2都表现出较好的吸附效果,其中V-ACF对CO_2和N_2的吸附系数高达9,说明ACF是很好... 详细信息

采用活性炭纤维(ACF)作为吸附材料,研究了ACF对CO_2和N_2的吸、脱分离特性。结果表明,粘胶基活性炭纤维(V-ACF)和聚丙烯腈基活性炭纤维(PAN-ACF)对CO_2和N_2都表现出较好的吸附效果,其中V-ACF对CO_2和N_2的吸附系数高达9,说明ACF是很好的吸附分离材料。ACF对不同烟气浓度和温度下对CO_2吸附的结果说明,ACF对于高浓度CO_2更易于脱除;讨论了ACF在不同解析温度或时间对吸附的影响和ACF的热稳定性,结果表明,在较高解析温度或者较长解析时间下更加容易脱除CO_2,且再生时间短,最佳的解析时间为15 min。经过相同的多次实验,ACF的性能稳定,再生效率稳定在86%。

关键词：活性炭纤维二氧化碳吸附系数再生效率

Transfer-free chemical vapor deposition graphene for nitride epitaxy: challenges, current status and future outlook

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Science China Chemistry 2024年第3期67卷 824-840页

作者： Xiang Gao Senlin Li Jingfeng Bi Kaixuan Zhou Meng Li Zhongfan Liu jingyu Sun College of Energy Soochow Institute for Energy and Materials InnovationsSUDA-BGI Collaborative Innovation CenterKey Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006China Beijing Graphene Institute Beijing 100095China Xiamen Silan Advanced Compound Semiconductor Co.Ltd. Xiamen 361026China

Graphene, a two-dimensional material with outstanding electrical and mechanical properties, has attracted considerable attention in the field of semiconductor technologies due to its potential use as a buffer layer for the epitaxial Ⅲ-nitride growth. In recent years, significant progress has been made in the chemical vapor deposition growth of graphene on various insulating substrates for the nitride epitaxy, which offers a facile, inexpensive, and easily scalable methodology. However, certain challenges are still present in the form of producing high-quality graphene and achieving optimal interface compatibility with Ⅲ-nitride *** this review, we provide an overview of the bottlenecks associated with the transferred graphene fabrication techniques and the state-of-the-art techniques for the transfer-free graphene growth. The present contribution highlights the current progress in the transfer-free graphene growth on different insulating substrates, including sapphire, quartz, SiO_(2)/Si, and discusses the potential applications of transfer-free graphene in the Ⅲ-nitride epitaxy. Finally, it includes the prospects of the transfer-free graphene growth for the Ⅲ-nitride epitaxy and the challenges that should be overcome to realize its full potential in this field.

关键词： Transfer-free chemical vapor deposition graphene for nitride epitaxy challenges current status and future outlook graphene

Extraction of Eugenol from Essential Oils by In Situ Formation of Deep Eutectic Solvents:A Green Recyclable Process

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Journal of Analysis and Testing 2024年第1期8卷 63-73页

作者： Lingqi Shen Xiangzi Jin Zhihui Zhang Yuexing Yi jingyu Zhang Zuguang Li College of Chemical Engineering Zhejiang University of TechnologyHangzhou 310014China Department of Chemistry Yanbian UniversityYanji 133002China Transfar Zhilian Co. Ltd.Hangzhou 311215China

Eugenol is extensively utilized in chemical *** actual production,it is mainly separated from clove essential oils(EOs)through acid-base *** this work,a simple,rapid and effective extraction process was developed for the extraction of eugenol from EOs samples by directly forming deep eutectic solvents(DESs)without using acid-base *** proposed process is designed to dissolve EOs in n-hexane and eugenol was highly selective extracted into DESs with tetrabutylammonium chloride(TBAC).Hydrogen bonds in DESs can be broken by addition of water,resulting in a separation of the two phases,thus obtaining a hydrophobic yellowish eugenol in the upper *** quaternary ammonium salt in the lower aqueous solution can be reused after *** most determining influence factors such as the structure of quaternary ammonium salt,the mole ratio of quaternary ammonium salt to eugenol and the amount of n-hexane were *** forming conditions of DESs were studied by Box-Behnken design(BBD).Experiment was carried out under the optimal conditions and good experimental result was demonstrated by the developed process,a high extraction recovery of 92.51% and the purity was about 98.50%,which verifies the excellent performance for the proposed process.

关键词： Eugenol Deep eutectic solvent Essential oils Tetrabutylammonium chloride

Role of binders in reactive composites: A case study with spherical B/Pb3O4 particles

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Particuology 2024年第10期93卷 170-179页

作者： Fan Wang Shanghao Du Jiahui Yang Zhihua Xue Jiafei Li Chongwei An jingyu Wang Bidong Wu School of Environment and Safety Engineering North University of ChinaTaiyuan030051China

The strategic selection of appropriate preparation methods and binder strategies is crucial for enhancing the particle and combustion performance of pyrotechnic delay compositions(PDCs).This study,utilizing droplet microfluidics technology(DMT)and micron-scale raw materials,prepared spherical B/Pb3O4 composite particles with varying concentrations of fluorine rubber(F2604).The morphology,specific surface area,bulk density,flowability,friction sensitivity,thermal decomposition,and combustion performance of these microspheres were *** results indicate that as the binder content increases,the particle size of the microspheres first decreases and then increases,the specific surface area decreases,and the bulk density increases,correlating with tighter binding of the reactant powders by the ***,tighter powder-to-powder binding results in a progressive decrease in the thermal decomposition peak temperature of the samples(from 404.2℃ to 346.4℃).Additionally,increased binder content reduces the friction sensitivity and combustion rate of the samples,which is attributed to the energy absorption properties of the *** to the control group,the microsphere samples exhibit significantly enhanced bulk density,flowability,friction safety,and combustion delay precision,potentially improving the reliability of PDCs in ignition sequences.

关键词： Pyrotechnic delay composition Droplet microfluidic technology Particle Binder B/Pb304 Combustion performance

A Novel High-Efficiency Transaction Verification Scheme for Blockchain Systems

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1613-1633页

作者： jingyu Zhang Pian Zhou Jin Wang Osama Alfarraj Saurabh Singh Min Zhu School of Computer&Communication Engineering Changsha University of Science&TechnologyChangsha410015China Science and Technology on Information Systems Engineering Laboratory School of Systems EngineeringNational University of Defense TechnologyChangsha410073China Computer Science Department King Saud UniversityRiyadh11437Saudi Arabia Department of Artificial Intelligence and Big Data Woosong UniversityDaejeon34606South Korea College of Information Science and Technology Zhejiang Shuren UniversityHangzhou310015China

Blockchain can realize the reliable storage of a large amount of data that is chronologically related and verifiable within the *** technology has been widely used and has developed rapidly in big data systems across various *** increasing number of users are participating in application systems that use blockchain as their underlying *** the number of transactions and the capital involved in blockchain grow,ensuring information security becomes *** the verification of transactional information security and privacy has emerged as a critical ***-based verification methods can effectively eliminate the need for centralized third-party ***,the efficiency of nodes in storing and verifying blockchain data faces unprecedented *** address this issue,this paper introduces an efficient verification scheme for transaction ***,it presents a node evaluation module to estimate the activity level of user nodes participating in transactions,accompanied by a probabilistic analysis for all ***,this paper optimizes the conventional transaction organization form,introduces a heterogeneous Merkle tree storage structure,and designs algorithms for constructing these heterogeneous *** analyses and simulation experiments conclusively demonstrate the superior performance of this *** verifying the same number of transactions,the heterogeneous Merkle tree transmits less data and is more efficient than traditional *** findings indicate that the heterogeneous Merkle tree structure is suitable for various blockchain applications,including the Internet of *** scheme can markedly enhance the efficiency of information verification and bolster the security of distributed systems.

关键词： Blockchain architecture transaction verification information security heterogeneous Merkle tree distributed systems

Debris flow runout behaviors considering the influences of densely populated buildings

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Journal of Mountain Science 2024年第8期21卷 2696-2712页

作者： ZHANG Shuai FANG Zhe DAI Cong WANG Shuairong PENG jingyu ZHOU Yiling SHEN Ping MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310058China State Key Laboratory of Internet of Things for Smart City and Department of Ocean Science and Technology University of MacaoMacao SAR 999078China

Debris flows pose serious risks to communities in mountainous areas,often resulting in large losses of human life and *** impeding presence of urban buildings often affects the runout behavior and deposition of debris *** the impact of different building densities and sizes on debris flow dynamics has yet to be quantified to guide urban planning in debris flow risk *** study focused on a debris flow that occurred in Zhouqu County,Gansu Province,China on August 7th,2010,which was catastrophic and destroyed many *** FLO-2D software was used to simulate this debris flow in two scenarios,*** presence and the absence of buildings,to obtain debris-flow intensity *** developed model was then used to further analyze the influence of large buildings and narrow channels within the urban *** simulation results show that considering the presence of buildings in the simulation is essential for accurate assessment of debris flow intensity and deposition *** layout of buildings in the upstream urban area,such as large buildings or parallel buildings which form narrow channels,can affect the flow velocity and depth of debris flow heading towards downstream *** mitigate damage to downstream buildings,the relative spacing(d/a)between upstream and downstream buildings should not exceed a value of two and should ideally be even *** findings provide valuable insights for improving the resistance of mountainous cities to urban debris flows.

关键词： Debris flow Risk Building blockage effect Zhouqu Urban layout

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球形催化剂颗粒内气体扩散及其有效因子

化学反应工程与工艺 2011年第4期27卷 289-296页

作者：闫云飞张力陈艳容冉景煜重庆大学低品位能源利用技术及系统教育部重点实验室重庆400030 重庆大学动力工程学院重庆400030

研究了三元催化器处理天然气汽车尾气过程中球形催化剂颗粒内的尾气扩散系数、浓度分布以及催化剂有效因子(η)等影响因素。结果表明,适当增大催化剂颗粒的平均孔半径或增大分子的平均自由程,可使扩散系数在整个催化剂颗粒内均保持较高... 详细信息

研究了三元催化器处理天然气汽车尾气过程中球形催化剂颗粒内的尾气扩散系数、浓度分布以及催化剂有效因子(η)等影响因素。结果表明,适当增大催化剂颗粒的平均孔半径或增大分子的平均自由程,可使扩散系数在整个催化剂颗粒内均保持较高的值。随Thiele模数(Φ_s)值的减小,催化剂颗粒内的相对浓度分布更为均匀,且呈整体增大的趋势,有效因子也增大。要消除内扩散的影响,使η相对较大,应降低Φ_s的值,并保持在0.0～0.5。

关键词：三元催化器天然气汽车尾气扩散 Thiele模数有效因子

Real-time model correction using Kalman filter for Raman-controlled cell culture processes

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Chinese Journal of Chemical Engineering 2024年第6期70卷 251-260页

作者： Xiaoxiao Dong Zhuohong He Xu Yan Dong Gao jingyu Jiao Yan Sun Haibin Wang Haibin Qu Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Hisun Biopharmaceutical Co.Ltd. Hangzhou 311404China

Raman spectroscopy has found extensive use in monitoring and controlling cell culture *** this context,the prediction accuracy of Raman-based models is of paramount ***,models established with data from manually fed-batch cultures often exhibit poor performance in Raman-controlled ***,there is a need for effective methods to rectify these *** objective of this paper is to investigate the efficacy of Kalman filter(KF)algorithm in correcting Raman-based models during cell ***,partial least squares(PLS)models for different components were constructed using data from manually fed-batch cultures,and the predictive performance of these models was ***,various correction methods including the PLS-KF-KF method proposed in this study were employed to refine the PLS ***,a case study involving the auto-control of glucose concentration demonstrated the application of optimal model correction *** results indicated that the original PLS models exhibited differential performance between manually fed-batch cultures and Raman-controlled *** glucose,the root mean square error of prediction(RMSEP)of manually fed-batch culture and Raman-controlled culture was 0.23 and 0.40 g·L^(-1).With the implementation of model correction methods,there was a significant improvement in model performance within Raman-controlled *** RMSEP for glucose from updating-PLS,KF-PLS,and PLS-KF-KF was 0.38,0.36 and 0.17 g·L^(-1),***,the proposed PLS-KF-KF model correction method was found to be more effective and stable,playing a vital role in the automated nutrient feeding of cell cultures.

关键词： Raman spectroscopy Model correction Algorithm Model-predictive control Bioprocess