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Experimental investigation of effect of partial filling on the impulse of pulse detonation engine

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Chinese Science Bulletin 2007年第20期52卷 2859-2865页

作者： ZHANG Qun YAN chuanjun FAN Wei li Qiang College of Power and Energy Northwestern Polytechnical University Xi'an 710072 China

Using poor-detonable liquid C8H16/air mixture with low-energy system (total spark energy of 50 mJ) and a new one-step detonation initiation method developed in this study, partial-tube fill experiments have been conducted in a fixed length PDE tube with a fuel/air mixture section of different length, covering a wide range of the detonation tube fill fraction (ratio of fuel/air mixture length to tube length). Impulse was calculated by integrating the pressure differential at the closed end of the tube. Based on the re- sults obtained experimentally, it is found that the fuel-based specific impulse declines when fill fraction increases. On the other hand, the total-mixture-based specific impulse rises as fill fraction increases. A multi-cycle partial-fill model is developed to predict the impulse obtained from a partially-filled detona- tion tube, which is valuable for the optimization of PDE performance.

关键词：脉冲爆震发动机填充分数冲量性能

Optimizing Domain Distribution of Grain Oriented Silicon Steel by Using Antimony as the Laser Surface Alloying Element

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Journal of Materials Science & Technology 2000年第2期16卷 163-164页

作者： Fengjiu SUN, Xingjie PENG and chuanjun li (Dept. of Physics, Northeastern University, Shengyang 110006, China) Dept. of Physics Northeastern University Shengyang 110006 China

For reducing the core loss of grain oriented silicon steel and improving its aging property, a new method, the LLSA by using Sb as the laser surface alloying element, was investigated, and at proper technique conditio... 详细信息

关键词： Optimizing Domain Distribution of Grain Oriented Silicon Steel by Using Antimony as the Laser Surface Alloying Element

Evolution of the microstructure and solute distribution of Sn-10wt% Bi alloys during electromagnetic field-assisted directional solidification

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Journal of Materials Science & Technology 2019年第4期35卷 568-577页

作者： Zhe Shen Minghu Peng Dongsheng Zhu Tianxiang Zheng Yunbo Zhong Weili Ren chuanjun li Weidong Xuan Zhongming Ren State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering Shanghai University

The effects of forced flows at different velocities on microstructure and solute distribution during the directional solidification of Sn-10 wt% Bi alloys under a simultaneous imposition of a transverse static magnetic field(TSMF) and an external direct current(DC) have been investigated experimentally and numerically. The experimental results show that the solid-liquid interface will gradually become sloping with the increase of the forced flow velocity when the thermoelectric magnetic convection(TEMC)dominates the forced flow at solidification front. However, the interface will gradually become planar as the flow velocity further increases when the electromagnetic convection(EMC) dominates the forced flow. Moreover, when the flow velocity gradually increases, the primary dendrite spacing decreases from384 to 105 μm accordingly. The simulation results show that the solute distribution at the two sides of the sample can be significantly changed by the forced flow at solidification front. The rejected solute will be unidirectionally transported to one side of the sample along the TEMC(a low-velocity forced flow),thereby causing the formation of a sloping interface. However, the rejected solute will be returned back along the EMC(a higher-velocity force flow), which results in a planar interface. Furthermore, the solute content at the two sides of the sample under the forced flows at different velocities was measured. The results are in good agreement with the simulation results, which shows that the solute content difference between the two sides of the sample reaches the maximum when a 0.5 T TSMF is applied, while the solute content difference decreases to zero with a simultaneous application of a 0.5 T TSMF and a 1.6 × 10~5 A/m^2 external DC.

关键词： Directional solidification Sn-Bi alloy Forced flow Solute distribution Numerical simulation Electromagnetic field

Mass transfer enhancement and hydrodynamic performance with wire mesh coupling solid particles in bubble column reactor

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Chinese Journal of Chemical Engineering 2024年第3期67卷 195-205页

作者： chuanjun Di Jipeng Dong Fei Gao Guanghui Chen Pan Zhang Jianlong li Key Laboratory of Multiphase Flow Reaction and Separation Engineering of Shandong Province College of Chemical EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Electromechanical Engineering Qingdao University of Science and TechnologyQingdao 266043China

It is of vital significance to investigate mass transfer enhancements for chemical engineering *** work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas-liquid mass transfer process in a bubble *** image velocimetry(PIV)technology was employed to analyze the flow field and bubble motion behavior,and dynamic oxygen absorption technology was used to measure the gas-liquid volumetric mass transfer coefficient(kLa).The effect of embedding wire mesh,adding solid particles,and wire mesh coupling solid particles on the flow characteristic and kLa were analyzed and *** results show that the gas-liquid interface area increases by 33%-72%when using the wire mesh coupling solid particles strategy compared to the gas-liquid two-phase flow,which is superior to the other two strengthening *** with the system without reinforcement,kLa in the bubble column increased by 0.5-1.8 times with wire mesh coupling solid particles method,which is higher than the sum of kLa increases with inserting wire mesh and adding particles,and the coupling reinforcement mechanism for affecting gas-liquid mass transfer process was discussed to provide a new idea for enhancing gas-liquid mass transfer.

关键词： Fluid mechanics Bubble Mass transfer Wire mesh coupling solid particles Particle image velocimetry Hydrodynamics

One-step preparation of efficient cuprous chloride catalyst for direct synthesis of trimethoxysilane

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Chinese Journal of Chemical Engineering 2024年第7期71卷 161-171页

作者： Jiaxin Zhang Lu Wang Zhiqiang Ma chuanjun Di Guanghui Chen Jipeng Dong Jianlong li Fei Gao Key Laboratory of Multiphase Flow Reaction and Separation Engineering of Shandong Province College of Chemical EngineeringQingdao University of Science and TechnologyQingdao 266042China

CuCl-based catalysts are the most commonly used catalysts for the“direct synthesis”of trimethoxysilane(M3).CuCl species are sensitive to air and water,and are prone to oxidation *** CuCl is directly used as a catalyst,it needs to be purified before the utilization,and the operating conditions for the catalyst preparation are relatively harsh,requiring the inert gas *** a high-temperature activation step required for CuCl-based catalysts used for catalyzing synthesis of M3 to form active phase Cu–Si alloys(Cu_(x)Si)with Si powder,in this work,a series of catalysts for the“direct synthesis”of M3 were obtained by a one-step high-temperature activation of the mixture of stable CuCl_(2) precursors,activated carbon-reducing agent,and Si powder,simultaneously achieving the reduction of CuCl_(2) to CuCl and the formation of active phase Cu_(x)Si alloys of CuCl with Si *** prepared samples were characterized through various characterization techniques,and investigated for the catalytic performance for the“direct synthesis”of ***,the operation conditions were optimized,including the activation temperature,catalyst dosage,Si powder particle size,and reaction *** characterization results indicate that during the one-step activation process,the CuCl_(2) precursor is reduced to CuCl,and the resulting CuCl simultaneously reacts with Si powder to form active phases Cu3Si and Cu15Si4 *** optimal catalyst Sacm(250,0.8:10)exhibits a good catalytic activity with selectivity of 95%and yield of 77%for M3,and shows a good universality for various alcohol ***,the catalytic mechanism of the prepared catalyst for the“direct synthesis”of M3 was discussed.

关键词： Trimethoxysilane Cuprous chloride Catalysis Catalyst activation Reduction Active phase formation

Thermal pretreatment of willow branches impacts yield and pore development of activated carbon in subsequent activation with ZnCl_(2) via modifying cellulose structure

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Chinese Journal of Chemical Engineering 2024年第5期69卷 227-237页

作者： linghui Kong Chao li Runxing Sun Shu Zhang Yi Wang Jun Xiang Song Hu Dong Wang chuanjun Leng Xun Hu School of Material Science and Engineering University of JinanJinan 250022China Joint International Research Laboratory of Biomass Energy and Materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China Shandong BASAN Graphite New Material Plant Zibo 255311China

Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the *** pretreatment of biomass could induce dehydration and/or aromatization to change the structure of cellulose/*** might interfere with evolution of structures of AC,which was investigated herein via thermal pretreatment of willow branch(WB)from 200 to 360℃and the subsequent activation with ZnCl_(2) at 550℃.The results showed that thermal pretreatment at 360℃(WB-360)could lead to substantial pyrolysis to form biochar,with a yield of 31.9%,accompanying with nearly complete destruction of cellulose crystals and remarkably enhanced aromatic ***,cellulose residual in WB-360 could still be activated to form AC-360 with specific surface area of 1837.9 m~2·g^(-1),which was lower than that in AC from activation of untreated WB(AC-blank,2077.8 m~2·g^(-1)).Nonetheless,the AC-200 from activation of WB-200 had more developed pores(2113.9 m~2·g^(-1))and superior capability for adsorption of phenol,due to increased permeability of ZnCl_(2) to the largely intact cellulose structure in *** thermal pretreatment did increase diameters of micropores of AC but reduced the overall yield of AC(26.8%for AC-blank versus 18.0%for AC-360),resulting from accelerated cracking but reduced intensity of ***-situ infrared characterization of the activation showed that ZnCl_(2) mainly catalyzed dehydration,dehydrogenation,condensation,and aromatization but not cracking,suppressing the formation of derivatives of cellulose and lignin in *** thermal pretreatment formed phenolic-OH and C=O with higher chemical innerness,which changed the reaction network in activation,shifting morphology of fibrous structures in AC-blank to“melting surface”in AC-200 or AC-280.

关键词： Thermal pretreatment Activation with ZnCl_(2) Willow branch Activated carbon Biochar

Symmetry breaking of highly symmetrical nanoclusters for triggering highly optical activity

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Fundamental Research 2024年第1期4卷 63-68页

作者： Xiao Wei Hao li Honglei Shen chuanjun Zhou Shuxin Wang Xi Kang Manzhou Zhu Department of Chemistry and Centre for Atomic Engineering of Advanced Materials Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information Technology and Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials.Anhui UniversityHefei 230601China

Developing new approaches to fulfill the enantioseparation of nanocluster racemates and construct cluster-based nanomaterials with optical activity remains highly desired in cluster science,because it is an essential prerequisite for fundamental research and extensive applications of these *** herein propose a strategy termed“active-site exposing and partly re-protecting”to trigger the symmetry breaking of highly symmetrical nanoclusters and to render cluster crystals optically *** vertex PPh_(3)of the symmetrical Ag_(29)(SSR)_(12)(PPh_(3))_(4)(SSR=1,3-benzenedithiol)nanocluster was firstly dissociated in the presence of counterions with large steric hindrance,and then the exposed Ag active sites of the obtained Ag_(29)(SSR)_(12)nanocluster were partly re-protected by Ag^(+),yielding an Ag_(29)(SSR)_(12)-Ag_(2)nanocluster with a symmetry-breaking ***_(29)(SSR)_(12)-Ag_(2)followed a chiral crystallization mode,and its crystal displayed strong optical activity,derived from CD and CPL ***,this work presents a new approach(i.e.,active-site exposing and partly re-protecting)for the symmetry breaking of highly symmetrical nanoclusters,the enantioseparation of nanocluster racemates,and the achievement of highly optical activity.

关键词： Atomically precise nanocluster Symmetry breaking Enantioseparation Circularly polarized luminescent Photoluminescence

历史与传说的双重变奏--青岛秦始皇传说的历史演变和文化动因

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民俗研究 2022年第6期 87-93页

作者：李传军青岛大学历史学院山东青岛266071

历史传说是民众对历史的记述和评价,是民众参与建构历史的一种载体,体现了民众对特定历史事件和历史人物的记忆和理解。地处青岛的琅琊台是秦始皇东巡的重要历史文化遗存,自古以来就流传着丰富的秦始皇传说。这些传说既有丰厚的历史依据... 详细信息

历史传说是民众对历史的记述和评价,是民众参与建构历史的一种载体,体现了民众对特定历史事件和历史人物的记忆和理解。地处青岛的琅琊台是秦始皇东巡的重要历史文化遗存,自古以来就流传着丰富的秦始皇传说。这些传说既有丰厚的历史依据,也有本地民众的再创造。青岛秦始皇传说发展演变的历史逻辑,体现了大历史与小历史的统一与背反。在传说中研究和探寻民众的历史情感、态度和价值观,可以深化对传说的历史价值的认知。

关键词：青岛秦始皇传说民众历史观

汉唐“风土记”中的西域风土映像——兼论华夷文化观在汉唐时期的转变

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西域研究 2011年第1期 20-27,142页

作者：李传军青岛大学师范学院历史系

汉唐时期,由于中外文化交流的兴盛,涌现出诸如《高僧法显西行记》、《佛国记》、《奉使高丽记》、《大唐西域记》等大量僧俗士人的西域行纪。这些著作的作者,以亲身的见闻和阅历,记载了大量的异域见闻,对于向中原人介绍异域风俗,促进西... 详细信息

汉唐时期,由于中外文化交流的兴盛,涌现出诸如《高僧法显西行记》、《佛国记》、《奉使高丽记》、《大唐西域记》等大量僧俗士人的西域行纪。这些著作的作者,以亲身的见闻和阅历,记载了大量的异域见闻,对于向中原人介绍异域风俗,促进西域文化在中原地区的传播,起了重要的作用。借助这种生动的西域风土映像,中原士人传统的华夷文化观念也发生了微调,变得更为开放,对西域文化也更易于理解、认知和接受。

关键词：华夷之辨西域行纪风土文化异域文化