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Microstructure refinement and work hardening in a machined surface layer induced by turning Inconel 718 super alloy

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 937-949页

作者： xiao-ping ren Zhan-qiang Liu School of Mechanical Engineering Shandong University Key Laboratory of High Efficiency and Clean Mechanical Manufacture Ministry of EducationShandong University

The microstructural changes in the machined surface layer of Ni-based super alloys essentially determine the final performance of the structural components of aerospace engines in which these alloys are *** this work,multiscale metallurgical observations using scanning electron microscopy,electron-backscatter diffraction microscopy,and transmission electron microscopy were conducted to quantitatively characterize the microstructure of the machined ***,to elucidate the factors that affect the formation of the refinement microstructure,the distributions of the deformation parameters(strain,strain rate,and temperature) in the machined subsurface were analyzed.A dislocation–twin interaction dynamic recrystallization mechanism for grain refinement during machining of Inconel 718 is ***,microhardness evolution induced by grain refinement in the machined surface is *** results suggest that the gradient microstructure and the work hardening can be optimized by controlling the cutting parameters during turning of Inconel 718.

关键词： grain refinement dislocation–twin interaction work hardening turning Inconel 718

Clinical characteristics of fatigued Parkinson’s patients and the response to dopaminergic treatment

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Translational Neurodegeneration 2016年第1期5卷 75-81页

作者： Rao Fu xiao-Guang Luo Yan ren Zhi-Yi He hong Lv Neurology Department Outpatient of Parkinson’s DiseaseFirst Affiliated Hospital of China Medical University155#Nanjing bei streetHeping DistrictShenyang 110001P R China

Background:Fatigue,which is commonly observed in Parkinson’s disease(PD),can greatly reduce quality of life and is difficult to *** here aimed to investigate the prevalence and characteristics of fatigue among PD patients and to explore an effective strategy to treat PD ***:This was an observational cross-sectional study conducted in northeastern *** examined fatigue in 222 PD patients from northeastern China using the Parkinson Fatigue Scale-16(PFS-16).The disease severity,depression,sleep and cognitive functioning were assessed with the Hoehn&Yahr staging(H-Y stage),Unified Parkinson’s Disease Rating Scale(UPDRS),Hamilton Depression Scale(HAMD),Parkinson’s Disease Sleep Scale(PDSS)and Montreal Cognitive Assessment(MoCA)by ***:The frequency of fatigue in PD patients was 59.46%.Fatigued patients had longer disease durations and greater disease severity than nonfatigued ***,fatigued PD patients scored significantly higher for all motor symptoms,except for tremor,and had more serious depressive symptoms and sleep disturbances than nonfatigued PD patients *** sleep disturbance severity was an independent factor for ***,43.04% of fatigued patients taking dopaminergic drugs had fatigue *** severity was identified as an independent factor for dopaminergic drug non-responsive ***:PD patients with severe sleep disturbances tend to suffer from *** improved fatigue only in PD patients with mild depression or no depression,implying that dopaminergic medication is required,but not sufficient,for fatigue suppression in PD patients with moderate or severe ***,restoring serotonergic neurotransmission as a combination therapy may offer a better strategy for the treatment of fatigue in these patients.

关键词： Parkinson’s disease Fatigue Sleep disorder Depression Dopaminergic drugs

X-ray and optical plateaus following the main bursts in GRBs and SNe Ⅱ-P: a hint about similar late injection behaviors?

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Research in Astronomy and Astrophysics 2013年第6期13卷 671-679页

作者： xiao-hong Cui ren-Xin Xu National Astronomical Observatories Chinese Academy of Sciences School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University

We analyze the emission plateaus in the X-ray afterglow light curves of gamma-ray bursts （GRBs） and those in the optical light curves of type Ⅱ plateau su- pernovae （SNe Ⅱ-P） in order to study whether they have similar late energy injection behaviors. We show that correlations of bolometric energies （or luminosities） between the prompt explosions and the plateaus for the two phenomena are similar. The energy emitted by SNe II-P are at the lower end of the range of possible energies for GRBs. The bolometric energies （or luminosities） in the prompt phase Eexpl （or Lexpl） and in the plateau phase E_plateau （or L_plateau） share relations of E_expl ∝E _0.73±0.14_plateau and L_expl ∝ L^-0.70_plateau. These results may indicate a similar late energy injection behavior that produces the observed plateaus in these two phenomena.

关键词： gamma rays: bursts -- supernovae: general -- methods: statistical

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喷印金属微滴撞击粗糙表面的分子动力学模拟

原子与分子物理学报 2025年第4期42卷 73-80页

作者：苏仁健陈小勇游自浩桂林电子科技大学机电工程学院桂林541004 广西制造系统与先进制造技术重点实验室桂林541004

研究金属微滴撞击固体表面的行为对预测微滴形态和实现高精度的喷印制造具有重要的意义.然而,由于微纳尺度下金属微滴撞击实验的难以开展,目前涉及金属微滴撞击粗糙表面的形态变化和热毛细效应机理尚不清楚.本文采用分子动力学模拟研究... 详细信息

研究金属微滴撞击固体表面的行为对预测微滴形态和实现高精度的喷印制造具有重要的意义.然而,由于微纳尺度下金属微滴撞击实验的难以开展,目前涉及金属微滴撞击粗糙表面的形态变化和热毛细效应机理尚不清楚.本文采用分子动力学模拟研究了镓铟微滴撞击粗糙表面的动态行为,定量分析了撞击速度、粗糙结构和不同温度对微滴撞击行为的影响.结果表明:随着撞击速度的提高,微滴先后呈现沉积、弹跳和破碎飞溅三种模式,且微滴的最大铺展因子与韦伯数呈幂函数关系.此外,通过修饰基底粗糙结构发现,结构间距或高度的变化对微滴的弹跳行为存在不同的影响机制,可以有效促使或抑制微滴的弹跳行为.最后,分析得出随着温度的提高,微滴的铺展直径会变大,产生的黏性耗散也会增大.研究结果对金属微滴撞击行为的有效预测提供了理论基础.

关键词：金属微滴撞击粗糙基底分子动力学

Comparisons of some difference forms for compressible flow in cylindrical geometry on arbitrary Lagrangian and Eulerian framework

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Applied Mathematics and Mechanics(English Edition) 2016年第11期37卷 1571-1586页

作者： Zhijun SHEN xiao LI Jian ren Institute of Applied Physics and Computational Mathematics Beijing 100088China Center for Applied Physics and Technology Peking UniversityBeijing 100071China Graduate School Chinese Academy of Engineering PhysicsBeijing 100088China

The study of cylindrically symmetric compressible fluid is interesting from both theoretical and numerical points of view. In this paper, the typical spherical sym- metry properties of the numerical schemes are discussed, and an area weighted scheme is extended from a Lagrangian method to an arbitrary Lagrangian and Eulerian （ALE） method. Numerical results are presented to compare three discrete configurations, i.e., the control volume scheme, the area weighted scheme, and the plane scheme with the addition of a geometrical source. The fact that the singularity arises from the geometri- cal source term in the plane scheme is illustrated. A suggestion for choosing the discrete formulation is given when the strong shock wave problems are simulated.

关键词： arbitrary Lagrangian and Eulerian (ALE) cylindrical geometry symmetrypreservation unstructured grid

MISCIBILITY,CRYSTALLIZATION AND MECHANICAL PROPERTIES OF PPC/PBS BLENDS

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Chinese Journal of Polymer Science 2007年第6期25卷 589-597页

作者： Hui-liang Zhang xiao-hong Sun Qing-yong Chen Min-qiao ren Zhi-hao Zhang hong-fang Zhang Zhi-shen Mo State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Graduate School of Chinese Academy of Science Changchun 130022 China

In this paper, melt blends of poly（propylene carbonate）（PPC） with poly（butylene succinate）（PBS） were characterized by dynamic mechanical analysis （DMA）, differential scanning calorimetry （DSC）, tensile testing, wide-angle X-ray diffraction （WAXD）, polarized optical microscopy and thermogravimetric analysis （TGA）. The results indicated that the glass transition temperature of PPC in the 90/10 PPC/PBS blend was decreased by about 11 K comparing with that of pure PPC. The presence of 10% PBS was partially miscible with PPC. The 90/10 PPC/PBS blend had better impact and tensile strength than those of the other PPC/PBS blends. The glass transition temperature of PPC in the 80/20, 70/30, and 60/40 PPC/PBS blends was improved by about 4.9 K, 4.2 K, and 13 K comparing with that of pure PPC, respectively; which indicated the immiscibility between PPC and PBS. The DSC results indicated that the crystallization of PBS became more difficult when the PPC content increased. The matrix of PPC hindered the crystallization process of PBS. While the content of PBS was above 20%, significant crystallization-induced phase separation was observed by polarized optical microscopy. It was found from the WAXD analysis that the crystal structure of PBS did not change, and the degree of crystallinity increased with increasing PBS content in the PPC/PBS blends.

关键词： Poly(propylene carbonate) Poly(butylene succinate) Miscibility Crystallization Mechanical properties.

Dynamical Feedback between Synoptic Eddy and Low-Frequency Flow as Simulated by BCC_CSM1.1(m)

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Advances in Atmospheric Sciences 2017年第11期34卷 1316-1332页

作者： Fang ZHOU hong-Li ren Laboratory for Climate Studies National Climate CenterChina Meteorological Administrationbeijing 100081china CMA-NJU Joint Laboratory for Climate Prediction Studies School of Atmospheric SciencesNanjing Universitynanjing 210093china Department of Atmospheric Science School of Environmental StudiesChina University of Geosciencewuhan 430074china

Since the interaction between atmospheric synoptic eddy （SE）（2-8 days） activity and low-frequency （LF）（monthly） flow （referred to as SELF） plays an essential role in generating and maintaining dominant climate modes, an evaluation of the performance of BCC_CSMI.I（m） in simulating the SE feedback onto the LF flow is given in this paper. The model captures well the major spatial features of climatological eddy vorticity forcing, eddy-induced growth rate, and patterns of SELF feedback for the climate modes with large magnitudes in cold seasons and small magnitudes in warm seasons for both the Northern and Southern Hemisphere. As in observations, the eddy-induced growth rate and SELF feedback patterns in the model also show positive SE feedback. Overall, the relationships between SE and LF flow show that BCC_CSM1. l（m） satisfactorily captures the basic features of positive SE feedback, which demonstrates the simulation skill of the model for LF variability. Specifically, such an evaluation can help to find model biases of BCC_CSM1.1 （m） in simulating SE feedback, which will provide a reference for the model＇s application.

关键词： model evaluation synoptic eddy feedback simulation eddy vorticity forcing eddy-induced growth rate patternsof synoptic eddy feedback

Impact of 1,25-(OH)_2D_3 on Left Ventricular Hypertrophy in Type 2 Diabetic Rats

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Chinese Medical Sciences Journal 2015年第2期30卷 114-120页

作者： Ying Fan Shan-xiao Zhang Meng ren Li-feng hong and xiao-ni Yan Department of Cardiology the Fifth Hospital of Wuhan & Institute of Cardiovascular Sciences of Jianghan University Department of Cardiology the First Hospital of Yangtze University

Objective To investigate the impact of 1, 25-(OH)2D3 on left ventricular hypertrophy(LVH) in type 2 diabetic rats. Methods Type 2 diabetic mellitus(DM) model rats were established by intraperitoneally injecting with 30 mg/kg streptozotocin. After 8 weeks, 19 male rats were identified as diabetic with left ventricular hypertrophy(LVH) by ultrasound examination, and randomly assigned into three groups: untreated(DM-LVH, n=7), treated with insulin(DM-LVH+INS, n=6), and treated with 1, 25-(OH)2D3(DM-LVH+VD, n=6). Healthy male rats were used as the controls group(n=6). The fasting blood glucose and the insulin level were determined weekly. The left ventricular mass index, myocardial collagen content, collagen volume fraction, and 1, 25-(OH)2D3-receptor level were determined by 4 weeks later. Results In the DM-LVH model group, the insulin level was significantly decreased compared with the non-diabetic control group(P<0.05), whereas the blood glucose, left ventricular mass index, myocardial collagen content, collagen volume fraction, and 1, 25-(OH)2D3-receptor expression were significantly increased(all P<0.05). In the DM-LVH+INS and DM-LVH+VD groups, the insulin levels were significantly increased compared with the DM-LVH model group(P<0.05), whereas the other parameters were significantly decreased(all P<0.05). Conclusion 1, 25-(OH)2D3 could reverse LVH in diabetic rats and that the mechanism may involve stimulating insulin secretion and reducing blood glucose via direct up-regulation of 1, 25-(OH)2D3-receptor expression.

关键词： 1, 25-(OH)2D3 left ventricular hypertrophy type 2 diabetes mellitus rat

Key Genes Involved in the Beneficial Mechanism of Hyperbaric Oxygen for Glioblastoma and Predictive Indicators of Hyperbaric Oxygen Prolonging Survival in Glioblastoma Patients

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Current Medical Science 2024年第5期44卷 1036-1046页

作者： Zi-qi ren ren-dong WANG Cong WANG xiao-hui ren Dong-guo LI Ya-ling LIU Qiu-hong YU Department of Hyperbaric Oxygen Beijing Tiantan HospitalCapital Medical UniversityBeijing100070China School of Biomedical Engineering Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical ApplicationCapital Medical UniversityBeijing100069China Department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijing100070China

Objective The prognosis of glioblastoma is poor,and therapy-resistance is largely attributed to intratumor *** oxygen(HBO)effectively alleviates ***,the sole role of HBO in glioblastoma remains *** previously reported that HBO can promote apoptosis,shorten protrusions,and delay growth of glioblastoma,but the molecular mechanism is *** aimed to test candidate genes in HBO-exposed glioblastoma cells and to analyze their correlation with the survival of glioblastoma *** Glioblastoma cell lines exposed to repetitive HBO or normobaric air(NBA)were collected for RNA isolation and microarray data *** analysis,KEGG pathway analysis and survival analysis of the differentially expressed genes(DEGs)were *** HBO not only inhibited hypoxia-inducing genes including CA9,FGF11,PPFIA4,TCAF2 and SLC2A12,but also regulated vascularization by downregulating the expression of COL1A1,COL8A1,COL12A1,RHOJ and FILIP1L,ultimately attenuated hypoxic microenvironment of *** attenuated inflammatory microenvironment by reducing the expression of NLRP2,CARD8,MYD88 and *** prevented metastasis by downregulating the expression of NTM,CXCL12,CXCL13,CXCR4,CXCR5,CDC42,IGFBP3,IGFBP5,GPC6,MMP19,ADAMTS1,EFEMP1,PTBP3,NF1 and *** upregulated the expression of BAK1,PPIF,DDIT3,TP53I11 and FAS,whereas downregulated the expression of MDM4 and SIVA1,thus promoting *** upregulated the expression of CDC25A,MCM2,PCNA,RFC33,DSCC1 and CDC14A,whereas downregulated the expression of ASNS,CDK6,CDKN1B,PTBP3 and MAD2L1,thus inhibiting cell cycle *** these DEGs,17 indicator-genes of HBO prolonging survival were *** HBO is beneficial for *** patients with these predictive indicators may prolong survival with HBO *** potential therapeutic targets especially COL1A1,ADAMTS1 and PTBP3 deserve further validation.

关键词： glioblastoma hyperbaric oxygen differentially expressed gene gene enrichment analysis survival analysis