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liF/GAP协同作用改善硼粉的燃烧性能

火炸药学报 2024年第3期47卷 279-286,I0006页

作者：伍双艳王吉权邵建刘俊陈九玉朱宝忠孙运兰常州大学石油与天然气工程学院·能源学院江苏常州213000

以氟化锂/缩水甘油叠氮化物聚合物(liF/GAP)为界面层对微米硼进行改性,研究liF/GAP协同作用对硼粉热行为、燃烧性能和凝聚相燃烧产物的影响。结果表明,通过硅烷偶联剂处理后,硼粉表面黏结性得以提高,liF能够较好地包覆在硼粉表面;GAP在... 详细信息

以氟化锂/缩水甘油叠氮化物聚合物(liF/GAP)为界面层对微米硼进行改性,研究liF/GAP协同作用对硼粉热行为、燃烧性能和凝聚相燃烧产物的影响。结果表明,通过硅烷偶联剂处理后,硼粉表面黏结性得以提高,liF能够较好地包覆在硼粉表面;GAP在400℃之前抑制了liF与硼表面氧化膜的反应,使liF的除膜效应延后至硼粉氧化增重阶段,从而将更多的活性硼暴露在空气中发生氧化,促进了硼粉的燃烧;liF和GAP协同作用显著改善了硼粉的燃烧性能,尤其当liF和GAP质量分数均为10%时,作用效果最为明显。此外,liF和GAP协同作用有效抑制了燃烧过程中硼粉团聚,使其凝聚相燃烧产物粒径降低。

关键词：物理化学硼颗粒 liF/GAP协同作用燃烧特性团聚抑制燃烧机理

As-cast structure of DC casting 7075 aluminum alloy obtained under dual-frequency electromagnetic field

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International Journal of Minerals,Metallurgy and materials 2014年第2期21卷 150-154页

作者： Zhi-hao Zhao zhen Xu Gao-song wang Qing-feng zhu jian-zhong Cui The Key Laboratory of the Ministry of Education of China for Electromagnetic Processing of materials Northeastern University

We have experimentally determined the as-cast structures of semi-continuous casting 7075 aluminum alloy obtained in the pres-ence of dual-frequency electromagnetic field. Results suggest that the use of dual-frequency electromagnetic field during the semi-continuous casting process of 7075 aluminum alloy ingots reduces the thickness of the surface segregation layer, increases the height of the melt menis-cus, enhances the surface quality of the ingot, and changes the surface morphology of the melt pool. Moreover, low-frequency electromag-netic field was found to show the most obvious influence on improving the as-cast structure because of its high permeability in conductors.

关键词： electromagnetic fields: semi-continuous casting aluminum alloys as-cast structure

航空用高品质7050铝合金大规格扁锭熔铸技术研究

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铸造 2024年第7期73卷 933-940页

作者：王剑马斯牧朱子宗王开西南铝业(集团)有限责任公司重庆401326 重庆大学材料科学与工程学院重庆400044

7050铝合金具有密度低、强度高、热加工性能优异等优点,在航空航天结构件上应用广泛。但在7050铝合金大规格铸锭半连续铸造过程中,存在热裂、成形困难、严重显微疏松和氧化夹杂等问题。本研究开发了大规格扁锭半连续铸造过程中合金熔体... 详细信息

7050铝合金具有密度低、强度高、热加工性能优异等优点,在航空航天结构件上应用广泛。但在7050铝合金大规格铸锭半连续铸造过程中,存在热裂、成形困难、严重显微疏松和氧化夹杂等问题。本研究开发了大规格扁锭半连续铸造过程中合金熔体冶金质量控制技术,系统考察了精炼工艺、晶粒细化技术对大规格扁锭品质的影响规律,确定了大规格扁锭铸造工艺。结果表明,优化工艺制度能严控熔体内氢和夹杂物含量,采用Al-Ti-C晶粒细化工艺制度将晶粒度控制在1~1.5级,高质量的熔体质量缓解了合金凝固收缩应变,极高比例地解决了扁锭开裂问题。最终,形成了一套适用于大规格7050合金扁锭的熔铸工艺制度。

关键词： 7050铝合金半连续铸造熔铸热裂微观组织

Evolution of Er^(3+) Distribution in the Oxyfluoride Glass Ceramics with Heating

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Chinese Journal of Structural Chemistry 2007年第3期26卷 303-308页

作者： ma En CHEN Da-Qin HU zhong-jian liU feng HUANG Zi-Xiang bao feng wang Yuan-Sheng State Key Laboratory of Structural Chemistry Fujian Institute of Research on theStructure of Matter Chinese Academy of Sciences Fuzhou Fujian 350002 China

The distribution characteristics of Er^3＋ ions doped in the oxyfluoride glass ceramics containing LaF3 nanocrystals heat-treated at 650 ℃ for different durations were investigated. The results of the integral absorption cross-section analysis demonstrated that the partition fraction of Er^3＋ in LaF3 nanocrystals increases with prolonging of heating time, The anomalous phenomena of Er^3＋ emissions in the up-and the down-conversion fluorescence spectra are well explained based on the calculated results.

关键词： oxyfluoride glass ceramics rare earth nanocrystal up-conversion integral absorption cross-section

Pattern of polycyclic aromatic hydrocarbons (PAHs) pollution in communication air of Hangzhou, China

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Journal of Environmental Sciences 2002年第2期14卷 145-150页

作者： wang Jing zhu li-zhong liU Yong-jian Department of Environmental Science Zhejiang UniversityHangzhou 310028China.

Nine PAHs were surveyed in communication air of Hangzhou. The results indicated that the PAHs pollution is very serious and the total sum of 9 PAHs, on the average are 3.39-13.82 μg/m 3. The PAHs signatures for all streets are similar to each other. Multivariate statistical techniques were used to investigate source apportionment for PAHs. A factor analysis/multiple regression model was successfully applied to the study. The most important three PAHs sources in communication air are diesel emission, gasoline engine emission, coal burning accounting for 61.1±6.4%, 19.9±8.3%, 10.8±10.8% of total PAHs, respectively. The relationship for three source tracers and total PAHs is: [PAHs] =1.471(±0.155)[Phen] + 2.538 (±2.522)[1-Mepy]+2.254 (±0.943)[Chry]+1.022 (±1.767).

关键词： PAHs air source apportionment city communication

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自振空化射流冲蚀模式与机制研究

机械工程学报 2024年第6期60卷 378-385页

作者：蔡腾飞潘岩王啸林马飞祝启恒韩健北京科技大学机械工程学院北京100083 北京科技大学顺德创新学院佛山528399

自振空化射流冲蚀模式是射流作业的最直观特征,但其演化机制尚不完全清晰,限制了模式的主动调控及射流高效应用。首先基于自振空化射流冲蚀试验,探明冲蚀模式随空化数和靶距的演变规律,通过高速摄像手段获取不同冲蚀模式下空泡云瞬时形... 详细信息

自振空化射流冲蚀模式是射流作业的最直观特征,但其演化机制尚不完全清晰,限制了模式的主动调控及射流高效应用。首先基于自振空化射流冲蚀试验,探明冲蚀模式随空化数和靶距的演变规律,通过高速摄像手段获取不同冲蚀模式下空泡云瞬时形态特征,采用正交模态分解得到空泡溃灭的统计规律;在此基础上,基于瞬态大涡模拟的计算流体动力学仿真方法,获得典型冲蚀模态下流体动力学特性,深入探究并揭示冲蚀模式形成机制。研究结果表明,不同空化数下随靶距变化,射流冲蚀特征呈现出3种典型冲蚀模式A、B、C,其中冲蚀模式A由冲蚀环1和较大冲蚀环2组成,冲蚀模式B仅包含冲蚀环1,冲蚀模式C主要由冲蚀环1及较小冲蚀环3组成;三种冲蚀模式中,均存在冲蚀环1,其能量最强,为主环,而不同冲蚀模式之间的转换方式与空化数有关。三种冲蚀模式形成机制如下:靶距较短时,冲蚀模式A中冲蚀环1由空化射流剪切生成的主空泡云溃灭空蚀而成,冲蚀环2由壁面涡环产生的次生空泡云溃灭造成;靶距较长时,冲蚀模式B仅包含冲蚀环1,该冲蚀模式下射流空蚀能力较强;特定空化数及靶距下,冲蚀模式C中冲蚀环1及冲蚀环3,分别由空化射流的主云团与次云团交替脱落后,依次撞击靶物产生。

关键词：自振射流空化射流冲蚀模式空泡云流体动力学

Investigation on Reaction Interface between the Aluminum and K2ZrF6 by Freezing the Molten Salt Reaction

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Acta Metallurgica Sinica(English Letters) 2017年第5期30卷 433-437页

作者： Qing-feng zhu Fei li Lei li Wen-Jing wang Gao-Song wang jian-zhong Cui Key Laboratory of Electromagnetic Processing of materials Ministry of EducationNortheastern UniversityShenyang 110819China School of materials Science and Engineering Northeastern UniversityShenyang 110819China

A reaction interface between the aluminum and K_2ZrF_6 during molten salt reaction process was frozen by quenching the mold in water, and the interface structure was analyzed to determine the formation process of Al_3Zr. Results show that a clear conical interface existed between the K_2ZrF_6 and aluminum. A zirconium accumulation layer with the thickness of about 2–3 lm was formed at the aluminum side of the interface. many initially formed Al_3Zr particles（with the size of 0.4–16 lm） distributed in this layer, most of which located at the interface. The morphology of Al_3Zr particles is closely related with their size. For the size of 0.4–1 lm, the Al_3Zr appeared as globular and ellipsoid shapes. When it grew to the size of 1–2 and 2–16 lm, it exhibited the rule cube shape, and rule cuboids shape, respectively.

关键词： Molten salt reaction Interface Aluminum Al3Zr particle Solidification

Achievement of high performance of sintered R-Fe-B magnets based on misch metal doped with PrNd nanoparticles

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Rare Metals 2018年第3期37卷 237-242页

作者： Qiang ma jian-Teng zhu Xue-feng Zhang Zeng-Ru Zhao Yan-li liu Gao-feng wang Yong-feng li zhu-Bai li Key Laboratory of Integrated Expoitation of Bayan Obo MultiMetal Resources Inner Mongolia University of Science and Technology College of Science Inner Mongolia University of Science and Technology

The magnetic properties and microstructure of sintered R-Fe-B（R, rare earth） magnets with nominal composition of（（PrNd）（1-x）MMx）（30）Fe（bal）B1（x = 0, 0.***.0.2,0.3, 0.4, 0.5 and 0.7; MM, misch metal） prepared using dual-alloy method were investigated. For x = 0.3, the maximum energy product（（BH）（max）） of the sintered magnet is higher than 318.4 kJ·m^-3,but intrinsic coercivity（H（cj）） is lower than 351.8 kA·m^-1. The La and Ce contents are obviously different in some matrix-phase grains, which proves that the multi-hard magnetic phases（La, Ce-rich and La, Ce-lean） exist in the magnets. The coercivity is improved by the method of doping PrNd nanoparticles without sacrificing other magnetic properties. An enhancement in coercivity from 517.2 to 872.9 kA·m^-1 is achieved by doping 5 wt% PrNd nanoparticles. Meanwhile, it could exhibit better magnetic properties（remanence Br = 1.332 *** coercivity H（cj）= 872.9 kA·m^-1 maximum energy product（BH）（max）=318.6 kJ·m^-3） and make the distribution of the intergranular phase become more homogeneous.

关键词： Permanent magnetic materials Nanoparticles Misch metal Dual-alloy Coercivity

Senktide blocks aberrant RTN3 interactome to retard memory decline and tau pathology in social isolated Alzheimer’s disease mice

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Protein & Cell 2024年第4期15卷 261-284页

作者： He-Zhou Huang Wen-Qing Ai Na Wei ling-Shuang zhu Zhi-Qiang liu Chao-Wen Zhou man-Fei Deng Wen-Tao Zhang Jia-Chen Zhang Chun-Qing Yang Ya-zhuo Hu Zhi-Tao Han Hong-Hong Zhang jian-Jun Jia Jing wang Fang-Fang liu Ke li Qi Xu Mei Yuan Hengye man Ziyuan Guo Youming Lu Kai Shu ling-Qiang zhu Dan liu Department of Pathophysiology School of Basic MedicineTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Medical Genetics School of Basic MedicineTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Pathology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450002China Department of Pathology School of Basic MedicineZhengzhou UniversityZhengzhou 450002China The Second Affiliated Hospital Department of NeurologyHengyang Medical SchoolUniversity of South ChinaHengyang 421001China Beijing Key Laboratory of Aging and Geriatrics National Clinical Research Center for Geriatric DiseaseInstitute of GeriatricsChinese PLA General Hospital and Chinese PLA Medical AcademyBeijing 100853China Department of Neurosurgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Neurology Union HospitalHuazhong University of Science and TechnologyWuhan 430022China Department of Biology Boston UniversityBostonMA 02215USA Center for Stem Cell and Organoid Medicine(CuSTOM) Division of Developmental BiologyCincinnati Children’s Hospital Medical CenterCincinnatiOH 45229USA

Sporadic or late-onset Alzheimer’s disease(LOAD)accounts for more than 95%of Alzheimer’s disease(AD)cases without any family *** genome-wide association studies have identified associated risk genes and loci for LOAD,numerous studies suggest that many adverse environmental factors,such as social isolation,are associated with an increased risk of ***,the underlying mechanisms of social isolation in AD progression remain *** the current study,we found that 7 days of social isolation could trigger pattern separation impairments and presynaptic abnormalities of the mossy fibre-CA3 circuit in AD *** also revealed that social isolation disrupted histone acetylation and resulted in the downregulation of 2 dentate gyrus(DG)-enriched miRNAs,which simultaneously target reticulon 3(RTN3),an endoplasmic reticulum protein that aggregates in presynaptic regions to disturb the formation of functional mossy fibre boutons(MFBs)by recruiting multiple mitochondrial and vesicle-related ***,the aggregation of RTN3 also recruits the PP2A B subunits to suppress PP2A activity and induce tau hyperphosphorylation,which,in turn,further elevates RTN3 and forms a vicious ***,using an artificial intelligence-assisted molecular docking approach,we determined that senktide,a selective agonist of neurokinin3 receptors(NK3R),could reduce the binding of RTN3 with its ***,application of senktide in vivo effectively restored DG circuit disorders in socially isolated AD *** together,our findings not only demonstrate the epigenetic regulatory mechanism underlying mossy fibre synaptic disorders orchestrated by social isolation and tau pathology but also reveal a novel potential therapeutic strategy for AD.

关键词： Alzheimer’s disease memory impairment synaptic disorder tau pathology