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Effects of phase change material(PCM)-based nanocomposite additives on thermal decomposition and burning characteristic of high energy propellants containing RDX

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Defence Technology（防务技术） 2022年第4期18卷 557-566页

作者： En-fa Fu Na Sun zheng-gang xiao Key Laboratory of Special Energy Materials Ministry of Education School of Chemical Engineering Nanjing University of Science and Technology

A kind of phase change material(PCM)-based nanocomposite was prepared and added into high energy propellants containing RDX as additives to investigate its effect on thermal decomposition and burning characteristic of high energy *** effect of PCM-based nanocomposites on thermal decomposition of high energy propellants is investigated by TG/DSC-FTIR-MS *** to the delayed protection effect(PCM-based nanocomposites can absorb lots of heat at the range of certain temperature when it undergoes structure change or phase transitions)of PCM-based nanocomposites under the thermal decomposition condition,the thermal stability of high energy propellants modified with PCMbased nanocomposites is *** the same time,the concentration of N2,NO2,H2O and CO_(2)is increased during thermal decomposition of high energy propellants whereas NO and CO is *** burning gaseous products and burning characteristic of high energy propellants are studied by the combination of closed bomb test and Fourier transform infrared *** main burning gaseous products are N2,CO_(2),CO,H2O,CH4,*** the high energy propellant modified with PCM-based nanocomposites,the concentration of CH4is increased while CO,CO_(2) and H2O is decreased under the high-pressure burning *** progressivity factor of high energy propellants is increased by22.2%compared with the control sample while the maximum pressure is merely decreased 1.25%after the addition of the PCM-based nanocomposite,thus PCM-based nanocomposites can be used to adjust the burning process and improve the burning progressivity of high energy *** study is expected to boost the practical application of PCM-based nanocomposite to the propellant formulation and effectively control the burning characteristic of high energy propellants.

关键词： Phase change material Propellants Nanocomposite Thermal decomposition Burning

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Investigation on thermal characteristics and desensitization mechanism of improved step ladder-structured nitrocellulose

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Defence Technology（防务技术） 2023年第2期20卷 93-102页

作者： Cheng-kai Pu Yu Luan Ming-jun Yi zheng-gang xiao Key Laboratory of Special Energy Materials Ministry of EducationSchool of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing210094People's Republic of China

Nitrocellulose,or cellulose nitrate,has received considerable interest due to its various applications,such as propellants,coating agents and gas ***,its high mechanical sensitivity caused many accidents during its storage and usage in *** this work,two kinds of insensitive step ladderstructured nitrocellulose(LNC)with different nitrogen contents were *** products were characterized by FT-IR,Raman,XRD,SEM,elemental analysis,TGA,DSC,accelerating rate calorimeter analysis(ARC),and drop weight test to study their molecular structure,thermal characteristics and desensitization *** with raw nitrocellulose,LNC has a sharper exothermic peak in the DSC and ARC *** H50values of the two kinds of LNC increased from 25.76 to 30.01 cm for low nitrogen content and from 18.02 to 21.84 cm for high nitrogen content,*** results show that the ladder-structure of LNC which provides regular molecular arrangement and a soft buffer made with polyethylene glycol could affect the energy releasing process of LNC and reduce the sensitivity of *** LNC provides an alternative to be used as a binder in insensitive propellants formulation.

关键词： Nitrocellulose Decomposition Desensitization Ladder structure Thermal characteristic Polyethylene glycol

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Dynamic hydraulic jump and retrograde sedimentation in an open channel induced by sediment supply: experimental study and SPH simulation

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Journal of Mountain Science 2019年第8期16卷 1913-1927页

作者： zheng xiao-gang CHEN Ri-dong LUO Min KAZEMI Ehsan LIU Xing-nian State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China Zienkiewicz Centre for Computational Engineering College of EngineeringSwansea UniversitySA1 8ENUK Department of Civil and Structural Engineering University of SheffieldSheffield S1 3JDUnited Kingdom

Mountainous torrents often carry large amounts of loose materials into the rivers, thus causing strong sediment transport. Experimentally it was found for the first time that when the intensive sediment motion occurs downstream over a gentle slope, the siltation of the riverbed is induced and the sediment particles can move upstream rapidly in the form of a retrograde sand wave, resulting in a higher water level along the river. To further study the complex mechanisms of this problem, a sediment mass model in the framework of the Smoothed Particle Hydrodynamics(SPH) method was presented to simulate the riverbed evolution, sediment particle motion, and the generation and development of dynamic hydraulic jump under the condition of sufficient sediment supply over a steep slope with varying angles. Because the sediment is not a continuous medium, the marker particle tracking approach was proposed to represent a piece of sediment with a marked sediment particle. The twophase SPH model realizes the interaction between the sediment and fluid by moving the bed boundary particles up and down, so it can reasonably treat the fluid-sediment interfaces with high CPU efficiency. The critical triggering condition of sediment motion, the propagation of the hydraulic jump and the initial siltation position were all systematically studied. The experimental and numerical results revealed the extra disastrous sediment effect in a mountainous flood. The findings will be useful references to the disaster prevention and mitigation in mountainous rivers.

关键词： Dynamic hydraulic jump Retrograde sedimentation Sediment supply Mountainous river Smoothed Particle Hydrodynamics Marked sediment particle

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Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

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Defence Technology（防务技术） 2014年第2期10卷 101-105页

作者： zheng-gang xiao San-jiu YING Fu-ming XU School of Chemical Engineering Nanjing University of Science and Technology

Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate(TEGDN)(TEGDN propellants) to high density *** obtained consolidated propellants are deterred and coated with the slow burning multi-layer *** maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/*** mechanic,deconsolidation and combustion performances are tested by the materials test machine,interrupted burning set-up and closed vessel,*** static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa,indicating that they can be applied in most circumstances of charge *** the samples are easy to deconsolidate in the interrupted burning ***,the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated *** the outer deterred multi-layer coating of consolidated samples is finished burning,the inner consolidated propellants continue to bum and breakup into aggregates and *** high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated *** preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb *** density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

关键词：燃烧性能推进剂多层涂布拆分材料试验机热固多层涂层乙二醇酯

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Study to mechanism of fluorescence enhancement of Dy3＋-Gd3＋- SSA-CTMAB system by resonance scattering-light spectroscopy

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Journal of Chemistry and Chemical Engineering 2009年第12期3卷 1-6,14页

作者： SA Pan-pan LIU xiao-yan YAO Yuan-yuan zheng Zhi-gang ZHANG xiao-wei YIN Hong-zong College of Chemistty and Material Science Shandong Agricultural University Taian 271018 China

The fluorescence enhancement mechanism of Dy3＋-Gd3＋- SSA-CTMAB system was studied by the resonance light scattering and fluorescence spectrum. In this paper, the influencing factors including the concentration of Gd3＋, ligands, pH value as well as surfactants were studied. As a result, the optimal experimental conditions were obtained. The existence of molecule congeries was proved by scattering-light spectrum.

关键词： dysprosium gadolinium sulfonic salicylic acid (SSA) hexadecyl trimethyl ammonium bromide (CTMAB) fluorescent spectroscopy resonance scattering- light spectroscopy fluorescence enhancement

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用电解原铝液生产高精6063铝合金圆铸锭的工艺研究

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轻合金加工技术 2009年第7期37卷 13-14页

作者：郑小刚张辉珠海鸿帆有色金属化工有限公司广东珠海519015 湖南大学材料科学与工程学院湖南长沙410083

针对国外客户对高精6063铝合金圆铸锭的质量要求,主要在电解原铝液熔体处理、炉内精炼、晶粒细化、炉外在线净化、均匀化处理和生产设备等方面进行了试验研究。现在我公司利用电解原铝液能够稳定生产出高精6063铝合金圆铸锭,满足了客户... 详细信息

针对国外客户对高精6063铝合金圆铸锭的质量要求,主要在电解原铝液熔体处理、炉内精炼、晶粒细化、炉外在线净化、均匀化处理和生产设备等方面进行了试验研究。现在我公司利用电解原铝液能够稳定生产出高精6063铝合金圆铸锭,满足了客户的需求。

关键词：电解原铝液高精6063铝合金圆铸锭研究

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石家庄西部太行山区景观格局时空变化

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生态学报 2007年第5期27卷 1993-2001页

作者：魏静郑小刚葛京凤河北师范大学资源与环境科学学院河北石家庄050016 河北省土地整理服务中心河北石家庄050051

基于1987、2000年两期TM、ETM+遥感数据资料,利用ArcGIS提取石家庄西部太行山区的景观类型转移矩阵,并结合重心模型,从时间和空间上对景观格局动态变化进行分析。结果表明:(1)1987～2000年,景观基质均为耕地,林地、草地、水域、建设用... 详细信息

基于1987、2000年两期TM、ETM+遥感数据资料,利用ArcGIS提取石家庄西部太行山区的景观类型转移矩阵,并结合重心模型,从时间和空间上对景观格局动态变化进行分析。结果表明:(1)1987～2000年,景观基质均为耕地,林地、草地、水域、建设用地和未利用土地作为斑块单元镶嵌其中;耕地、草地和水域的面积均为减少,其中草地面积减少量最大,主要向林地转化;林地、建设用地和未利用土地的面积均为增加,其中建设用地面积增加量最大,主要由未利用土地转化而来。(2)1987～2000年间,水域重心迁移距离最大;耕地、水域和建设用地的重心偏移方向为北偏西;林地和草地的重心偏移方向为北偏东;未利用土地的重心偏移方向为南偏西。

关键词：石家庄太行山区转移矩阵重心模型

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四方体MgO的制备及对有机染料的吸附

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人工晶体学报 2018年第3期47卷 649-657页

作者：付孝锦黄明王珂刘敏郑小刚刘勇内江师范学院化学化工学院内江641199

以六水氯化镁和六次甲基四胺为原料,采用水热法合成四方体MgO,考察其对有机染料甲基橙和亚甲基蓝的吸附行为。通过TGA-DTA、SEM、XRD、N2-sorption和FT-IR等手段表征样品。结果表明,原料浓度、温度和表面活性剂对四方体MgO结构的形成影... 详细信息

以六水氯化镁和六次甲基四胺为原料,采用水热法合成四方体MgO,考察其对有机染料甲基橙和亚甲基蓝的吸附行为。通过TGA-DTA、SEM、XRD、N2-sorption和FT-IR等手段表征样品。结果表明,原料浓度、温度和表面活性剂对四方体MgO结构的形成影响较小,而反应时间的延长有助于有序结构的组装。温度170℃、时间24 h、MgCl_2·6H2O与C6H12N4浓度比为1∶2和表面活性剂PVP是制备四方体MgO的最佳条件。在溶液浓度10 mg·L-1的单一吸附实验过程中,四方体MgO对甲基橙和亚甲基蓝的去除率分别为91.3%和22.3%,吸附过程均为单层吸附且符合Langmuir等温吸附模型和伪二级吸附动力学方程。在溶液浓度40 mg·L-1、甲基橙和亚甲基蓝浓度比3∶1的混合溶液吸附过程中,四方体MgO对甲基橙和亚甲基蓝的去除率分别为80.1%和97.9%。

关键词：四方体MgO 亚甲基蓝甲基橙竞争吸附吸附稳定性

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关于杨重骏的一个猜测

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厦门大学学报（自然科学版） 2006年第4期45卷 450-453页

作者：陈新香郑晓刚厦门大学数学科学学院福建厦门361005 九江学院理学院江西九江332005

杨重骏在研究多项式的惟一性时曾提出如下猜测:对于两个次数相同的非常数多项式,若它们在两个不同点值分布相同则这两个多项式相等或者它们的和退化为一个常数(等于这两个数的和).这个猜测不仅是亚纯函数惟一性中的问题,莫宗坚在研究多... 详细信息

杨重骏在研究多项式的惟一性时曾提出如下猜测:对于两个次数相同的非常数多项式,若它们在两个不同点值分布相同则这两个多项式相等或者它们的和退化为一个常数(等于这两个数的和).这个猜测不仅是亚纯函数惟一性中的问题,莫宗坚在研究多项式群结构时,也提出过这个问题.本文用代数的方法得到了n次多项式在不同两点的值分布至少有n+1个.根据这些值的重数关系及这两个多项式的部分系数关系得到猜测成立的一些充分条件,同时得到了当n小于或等于3时猜测成立.

关键词：多项式多项式的零点 IM公共值

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电镜酶细胞化学与免疫电镜双重标记的研究

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中华物理医学杂志 1992年第3期14卷 174-176页

作者：郑晓刚张太和 210002

通过人心房肌细胞胞嘧啶单核苷酸酶（CMPase）和心钠素的超微结构定位，探讨建立电镜酶细胞化学与免疫电镜双重标记的方法。结果表明该方法简便易行，定位准确，相互鉴别清楚，有助于研究同一细胞中酶与抗原的相互关系，是一项具有实用... 详细信息

通过人心房肌细胞胞嘧啶单核苷酸酶（CMPase）和心钠素的超微结构定位，探讨建立电镜酶细胞化学与免疫电镜双重标记的方法。结果表明该方法简便易行，定位准确，相互鉴别清楚，有助于研究同一细胞中酶与抗原的相互关系，是一项具有实用价值的新方法。

关键词：电镜细胞化学免疫组化电镜胶体金

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