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Effect of mixing temperature on microstructure of an Al-Si alloy prepared by controlled diffusion solidification

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China Foundry 2023年第3期20卷 241-252页

作者： Han Xue Ti-jun Chen Xue-zheng Zhang guang-li bi Ying Ma Ren-guo Guan State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina

The effects of mixing temperature,i.e.,the temperatures of two precursor melts(pure Al and Al-12Si),on the temperature and solute fields of resultant mixture,the nucleation and growth,and the size and morphology of primary grains during controlled diffusion solidification(CDS) of Al-8Si alloy were investigated by using simulation and *** results indicate that a lower mixing temperature is helpful for achieving more supercooled microscale Al-rich pockets in the mixture,and increasing the width and supercooling degree of supercooling zone in the Al-rich pockets,and thus,the nucleation *** nuclei grow up in nondendritic mode,resulting in spheroidal,at least,nondendritic *** a successful CDS,the superheat degrees of the two precursor melts should be limited within several degrees,and it is not necessary to extra stipulate the superheat degree of target alloy melt(Al-8Si) when the requirement about Gibbs energies of the three melts is *** observation on casting microstructures shows that the employed simulation and calculation processes are reasonable and the achieved results are reliable.

关键词： controlled diffusion solidification Al-Si alloy nucleation and growth supercooling nondendritic grains

Efficient fabrication of semisolid nondendritic Al alloy slurry with high quality

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China Foundry 2022年第2期19卷 117-130页

作者： Zong-xu Zhang Ti-jun Chen Kun liu Han Xue Jia-chen Qi guang-li bi Ying Ma State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China

Subjecting a normal mechanical vibration to a cooling slope plate,is a proposed method for preparing semisolid nondendritic slurry,named shear-vibration coupling sub-rapid solidification(SCS).Taking Al-8Si alloy as model material,the temperature field and distribution field of solid or liquid phase during SCS were simulated using COMSOL Multiphysics software to primarily choose the optimal processing ***,the slurries were prepared with the parameters selected according to the simulation results and the microstructures of the slurries were experimentally *** indicate that the simulation results could provide a basis for roughly choosing the processing parameters,although the calculated solid fractions are always higher than the experimental *** processing parameters affect the primary grain size,shape factor and solid fraction mainly through altering the contact duration of melt on the plate,and thus affecting the cooling effect on the melt,nucleation rate,and grain dissociation and *** with optimized processing parameters show that the primary grains in the slurry have an average size of about 32μm and shape factor of 1.38,and are quite uniform,even at the highest pouring rate of 2.81 kg·s^(-1),the size and shape factor are about 46μm and 1.7,respectively,which implies that the proposed SCS is a promising technology for efficient fabrication of high-quality Al slurry available for engineering applications.

关键词： semisolid nondendritic slurry semisolid forming simulation primary grains shape factor

Effect of Zn, Cu and Ni addition on microstructure and mechanical properties of ascast Mg-Dy alloys

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China Foundry 2016年第1期13卷 54-58页

作者： guang-li bi Xiao-mei Luo Jing Jiang Yong-gang Zhang Jian-ji Xu Jie-ming Chen Yuan-dong li Ying Ma State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Key Laboratory of Nonferrous Metal alloys and Processing Ministry of Education Lanzhou University of Technology

This paper presents some research information on the effects of Zn, Cu and Ni on the microstructure and mechanical properties of as-cast Mg-2Dy(at.%) alloys. The Mg-2Dy alloy is composed of α-Mg and Mg24Dy5 phases. With the addition of 0.5at.%Zn, 0.5at.%Cu and 0.5at.%Ni, respectively, besides α-Mg, the long period stacking order(LPSO) phases containing Zn, Cu, and Ni precipitated in the α-Mg interdentritic boundary. The addition of Ni effectively refined the dendrite arm spacing. The as-cast Mg-2Dy-0.5Ni alloy exhibited the best tensile strengths and elongation. The better mechanical properties were mainly attributed to small secondry dendrite arm spacing(SDAS) and high volume fraction of LPSO phases.

关键词： Mg-Dy-Zn(Cu,Ni) alloys LPSO phase microstructure mechanical properties

Effects of melt treatment temperature and isothermal holding parameter on water-quenched microstructures of A356 aluminum alloy semisolid slurry

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Transactions of Nonferrous Metals Society of China 2018年第3期28卷 393-403页

作者： Ming li Yuan-dong li guang-li bi Xiao-feng HUANG Ti-jun CHEN Ying MA State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou 730050China Key Laboratory of Nonferrous Metal Alloys and Processing Ministry of EducationLanzhou University of TechnologyLanzhou 730050China

The semisolid slurry of the A356 aluminum alloy was prepared by self-inoculation method(SIM),the effects of melt treatment temperatures and isothermal holding parameters on water-quenched microstructures of A356 aluminum alloy semisolid slurry were investigated,and the solidification behavior of the remaining liquid phase(secondary solidification)was *** results indicate that the melt treatment temperature has significant effects on the final semisolid *** semisolid slurry which is suitable for the rheological forming can be produced when the melt treatment temperature is between 680 and 690°*** the isothermal holding process,the growth rate of the primary particles conforms to the dynamic equation of Dt 3-Do3=Kt,and the coarsening rate of the primary particles is the fastest when the isothermal holding temperature is 600°***,the isothermal holding time also has obvious effect on the secondary solidification *** secondary particles are the smallest and roundest when the isothermal holding time is 3 *** amount of the secondary particles gradually increases with the increase of isothermal holding temperature,and the eutectic reaction therefore is confined into small intergranular areas,contributing to the compactness of the final solidified eutectic structures.

关键词： aluminum alloy semisolid self-inoculation method secondary solidification primary particles eutectic structure

Effects of solid solution treatment and cooling on morphology of LPSO phase and precipitation hardening behavior of Mg-Dy-Ni alloy

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Transactions of Nonferrous Metals Society of China 2017年第11期27卷 2381-2389页

作者： li-tao YUAN guang-li bi Yuan-dong li Jing JIANG Yu-xiang HAN Da-qing FANG Ying MA State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of Technology Lanzhou 730050 China College of Materials Science and Engineering Taiyuan University of Science and Technology Taiyuan 030024 China

Effects of solid solution treatment and cooling on the morphology of long period stacking order(LPSO)phase and precipitation hardening behavior of Mg?2Dy?0.5Ni(molar fraction,%)alloy were *** of the as-cast alloy mainly consisted ofα-Mg phase,bamboo-like Mg12DyNi phase with LPSO structure distributed between dendrites and small amounts of cubic Dy *** solid solution treatment at565oC for12h and subsequent different cooling conditions,dot-shaped,block,fine lamellar and rod-shaped LPSO phases precipitate in Mg matrix,*** continuous cooling conditions(furnace and air cooling),the fine lamellar LPSO phase generally forms in grain interior and its volume fraction increases and block LPSO phase coarsens with increasing cooling *** discontinuous cooling conditions(air cooling after furnace cooling to415and265°C),the dot-shaped LPSO grows into the rod-shaped phase,which results in an decrease of cooling hardening behavior of alloy.

关键词： Mg.Dy.Ni alloy LPSO phase microstructure precipitation hardening

Compressive anisotropy of extruded Mg-Dy-Zn alloy sheet

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Transactions of Nonferrous Metals Society of China 2016年第2期26卷 390-397页

作者：罗晓梅毕广利姜静李明李荣广李元东马颖郝远兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室兰州730050 兰州理工大学有色金属合金及加工教育部重点实验室兰州730050 沈阳化工大学机械工程学院沈阳110142

Compressive anisotropy of extruded Mg-2Dy-0.5Zn （mole fraction, %） alloy sheet was investigated. The alloy sheet was mainly composed ofα-Mg, （Mg, Zn）xDy phase and a large number of long period stacking ordered （LPSO） phases distributed along the extrusion direction. The compressive experimental results show that the alloy sheet exhibits an obvious compressive anisotropy. The compressive strength of the specimen in the extrusion direction （ED） is higher than those of the specimens in the transverse direction （TD） and 45° inclined to the extrusion direction. The compressive yield strength （CYS）, ultimate compressive strength （UCS） and compressive strain of the specimen in the ED are 274.65 MPa, 518.94 MPa and 12.93%, respectively. The compressive anisotropy is mainly attributed to the distribution of LPSO phase and formation of〈10 10〉//ED fiber texture in the deformed grains.

关键词： Mg-Dy-Zn alloy microstructure texture LPSO phase compressive anisotropy

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盐酸咪唑苯脲的合成

中国医药工业杂志 2008年第2期39卷 88-89页

作者：李光壁王明刚天津科技大学海洋科学与工程学院天津300457 山东大学化学与化工学院山东济南250100

苄腈经混酸硝化、与乙二胺在硫粉催化下环合、铁粉还原得2-(3-氨基苯基)-4,5-二氢-1H-咪唑二盐酸盐,再与双光气缩合后成盐,制得抗梨形虫病药盐酸咪唑苯脲,总收率约50%。

关键词：咪唑苯脲抗梨形虫药合成

非均相UV/Fenton体系氧化降解愈创木酚的研究

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中国造纸学报 2010年第2期25卷 45-49页

作者：王昶刘芳贾青竹张丽萍李光璧天津科技大学海洋科学与工程学院天津300457

以浸渍法制备的Fe3+/γ-Al2O3为催化剂,研究了非均相UV/Fenton体系对木素类模型物愈创木酚的处理效果,并与非均相Fenton体系作比较。实验结果表明,非均相UV/Fenton体系能够有效地降解结构稳定的木素类模型物愈创木酚。在室温、初始pH值... 详细信息

以浸渍法制备的Fe3+/γ-Al2O3为催化剂,研究了非均相UV/Fenton体系对木素类模型物愈创木酚的处理效果,并与非均相Fenton体系作比较。实验结果表明,非均相UV/Fenton体系能够有效地降解结构稳定的木素类模型物愈创木酚。在室温、初始pH值为6.3、投加2倍理论量的H2O2和1g/L自制的催化剂(Fe3+与H2O2的摩尔比为1∶31.6)、反应60min,初始质量浓度为50mg/L的条件下,愈创木酚的去除率可达到100%。非均相UV/Fenton和非均相Fenton反应90min,愈创木酚的总有机碳去除率分别为94.3%和17.2%,由此可知,紫外光与Fenton试剂存在协同效应,使体系的氧化能力明显增强。愈创木酚的矿化速率慢于去除速率,说明愈创木酚并不是立刻被降解为CO2和H2O,而是先被降解为其他小分子中间产物,最终完全矿化。

关键词：非均相 UV/Fenton H2O2 愈创木酚木素

Cortico-striatal gamma oscillations are modulated by dopamine D3 receptors in dyskinetic rats

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Neural Regeneration Research 2025年第4期20卷 1164-1177页

作者： Pengfei Wang Yuewei bi Min li Jiazhi Chen Zhuyong Wang Huantao Wen Ming Zhou Minjie Luo Wangming Zhang Neurosurgery Center Department of Pediatric NeurosurgeryGuangdong Provincial Key Laboratory on Brain Function Repair and RegenerationZhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina

Long-term levodopa administration can lead to the development of levodopa-induced *** oscillations are a widely recognized hallmark of abnormal neural electrical activity in levodopa-induced ***,studies have reported increased oscillation power in cases of levodopa-induced ***,little is known about how the other electrophysiological parameters of gamma oscillations are altered in levodopa-induced ***,the role of the dopamine D3 receptor,which is implicated in levodopa-induced dyskinesia,in movement disorder-related changes in neural oscillations is *** found that the cortico-striatal functional connectivity of beta oscillations was enhanced in a model of Parkinson’s ***,levodopa application enhanced cortical gamma oscillations in cortico-striatal projections and cortical gamma aperiodic components,as well as bidirectional primary motor cortex(M1)↔dorsolateral striatum gamma *** of PD128907(a selective dopamine D3 receptor agonist)induced dyskinesia and excessive gamma oscillations with a bidirectional M1↔dorsolateral striatum ***,administration of PG01037(a selective dopamine D3 receptor antagonist)attenuated dyskinesia,suppressed gamma oscillations and cortical gamma aperiodic components,and decreased gamma causality in the M1→dorsolateral striatum *** findings suggest that the dopamine D3 receptor plays a role in dyskinesia-related oscillatory activity,and that it has potential as a therapeutic target for levodopa-induced dyskinesia.

关键词： aperiodic components dopamine D3 receptor dorsolateral striatum functional connectivity gamma oscillations levodopa-induced-dyskinesia local field potentials neuromodulation Parkinson’s disease primary motor cortex