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不同预时效挤压态Mg−Gd−Y−Zn−Zr合金的再结晶行为和强化机制
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作者 徐健 郑杰 +5 位作者 刘莞尔 黄有旺 闫钊鸣 张治民 王强 薛勇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第2期480-503,共24页
通过控制预时效时间制备3种不同状态的试样,研究不同预时效状态对挤压态Mg−9.5Gd−4Y−2.2Zn−0.5Zr(质量分数,%)合金的动态再结晶行为(DRX)和性能的影响。结果表明,欠时效挤压(UAE)样品的细晶体积分数为17.4%,而峰时效挤压(PAE)和过时效挤... 通过控制预时效时间制备3种不同状态的试样,研究不同预时效状态对挤压态Mg−9.5Gd−4Y−2.2Zn−0.5Zr(质量分数,%)合金的动态再结晶行为(DRX)和性能的影响。结果表明,欠时效挤压(UAE)样品的细晶体积分数为17.4%,而峰时效挤压(PAE)和过时效挤压(OAE)样品的细晶体积分数分别达到89.7%和50.4%。在晶粒内部和晶界处分布的致密、细小的β颗粒相通过粒子激发形核机制显著提高了形核位点和位错密度。然而,致密针状γ'相抑制位错滑移,延迟DRX形核。PEA和OAE样品中细小晶粒的差异归因于原始颗粒相的数量和尺寸的不同,而其拉伸性能的差异归因于不同的显微组织。由于晶界强化和析出强化机制的贡献更大,PAE样品具有更优异的拉伸性能。 展开更多
关键词 Mg−Gd−Y−Zn−Zr合金 预时效处理 再结晶行为 强化机制 粒子刺激形核
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水线草质量控制体系构建(英文)
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作者 林艳 李洪权 +6 位作者 夏伯候 张智敏 李亚梅 张晓青 吴萍 林丽美 廖端芳 《Digital Chinese Medicine》 2018年第4期302-309,共8页
目的水线草为中国等东南亚国家的主要抗肿瘤药物,但是目前没有切实可行的质量标准对其进行有效地控制,本研究欲构建水线草全面的质量控制体系。方法采用显微鉴别法对水线草进行粉末和横切面性状鉴别;采用薄层色谱法进行定性鉴别;采用高... 目的水线草为中国等东南亚国家的主要抗肿瘤药物,但是目前没有切实可行的质量标准对其进行有效地控制,本研究欲构建水线草全面的质量控制体系。方法采用显微鉴别法对水线草进行粉末和横切面性状鉴别;采用薄层色谱法进行定性鉴别;采用高效液相色谱法建立水线草区别于易混淆品种白花蛇舌草的特征图谱,且对特征峰成分耳草酮A进行定量研究;采用2015年版中国药典规定的方法分别对水线草的水分、总灰分、酸不溶性灰分、重金属和农药残留量进行检测。结果水线草横切面内含草酸钙针晶束,偶见小油滴。薄层色谱法检出水线草样品中区别于白花蛇舌草的3个蓝色荧光斑点;高效液相色谱法(HPLC)建立了含5个特征峰的水线草特征图谱,并测定主要特征峰耳草酮A,该成分在0.0000527~0.00211 mg/mL范围内线性关系良好,线性方程为Y=3.15×10~8X+312.04(r^2=1.000),平均回收率为100.4%,RSD为0.85%,精密度(RSD 0.92%)、重复性(RSD 0.14%)、稳定性(RSD 0.85%)都达标,15批水线草中耳草酮A的质量分数在0.00017~0.00113%;水分、总灰分、酸不溶性灰分分别为8.80%~11.2%、7.00%~15.3%和0.440%~7.70%;重金属铅、砷、汞、镉、铜的含量分别为1.60~4.60、0.650~1.60、0.0300~0.100、0.240~0.690和10.1~16.6μg/g;农药残留含量低于检测限0.00100 ppm。结论此质量标准体系可有效区分水线草和易混淆品种白花蛇舌草,从而全面控制水线草质量,保证水线草的真伪优劣,为水线草临床使用提供参考。 展开更多
关键词 水线草 白花蛇舌草 耳草酮A 薄层法 高效液相色谱法(HPLC) 质量标准
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Development of 3D printing entity slicing software
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作者 Yang Guan Xun Sun +4 位作者 Lei Jin Xin-li Guo zhi-min zhang Guo-yan Shui Lan-bo Ma 《China Foundry》 SCIE CAS 2021年第6期587-592,共6页
Based on STL(stereo lithography)format file and with Microsoft Visual C^(++)6.0 programming language,a 3D printing slicing software appropriate for the surface strengthening of the parts has been developed,which inclu... Based on STL(stereo lithography)format file and with Microsoft Visual C^(++)6.0 programming language,a 3D printing slicing software appropriate for the surface strengthening of the parts has been developed,which includes three functions:3D model import,model slicing and data export.Through the grouping of STL model triangle facets before slicing,the judgment times of the relationship between the triangle facets and the cutting planes are reduced,and the slicing efficiency is improved.Aiming at the fact that the surface should be strengthened when the part is formed by using of 3D printing process,the function of identifying and marking the surface of the geometric entity is accomplished in the slicing software,which can strengthen the surface of the part according to the user’s requirements.The developed slicing software can provide an entity slicing file for 3D printing equipment.The related functions can be adjusted and improved according to user’s needs,which makes the software convenient and flexible to use. 展开更多
关键词 STL format 3D printing SLICING surface strengthening
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Correlation of serum NGAL and OPG contents with the change of carotid plaques in diabetic patients
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作者 You Gao Ling zhang +1 位作者 Shao-Jun Wei zhi-min zhang 《Journal of Hainan Medical University》 2018年第20期17-20,共4页
Objective:To investigate the correlation of serum NGAL and OPG contents with the change of carotid plaques in diabetic patients.Methods: A total of 99 patients with type 2 diabetes mellitus combined with carotid plaqu... Objective:To investigate the correlation of serum NGAL and OPG contents with the change of carotid plaques in diabetic patients.Methods: A total of 99 patients with type 2 diabetes mellitus combined with carotid plaque who were treated in our hospitals between February 2016 and March 2018 were selected as group A and 86 patients with carotid plaque alone were selected as group B. The serum contents of NGAL OPG, inflammatory markers and lipid metabolism indexes were compared between the two groups, and Pearson test was used to evaluate the inner link of serum NGAL and OPG contents with carotid plaque properties in diabetic patients with carotid plaques.Results: Serum NGAL content of group A was higher than that of group B whereas OPG content was lower than that of group B;serum inflammatory markers MMP-9, IL-1β, IL-17 and CRP contents were higher than those of group B;serum lipid metabolism indexes ApoB and Lp-PLA2 contents were higher than those of group B whereas ApoAⅠcontent was lower than that of group B. Correlation analysis showed that serum NGAL and OPG contents of patients with diabetes mellitus combined with carotid plaque were directly correlated with the content of inflammatory markers and lipid metabolism indexes.Conclusion: Serum NGAL content abnormally increases whereas OPG content abnormally decreases in patients with diabetes mellitus combined with carotid plaque, and they are directly correlated with the stability of carotid plaque. 展开更多
关键词 Diabetes MELLITUS NGAL OPG CAROTID PLAQUE
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Hot Compression Behavior of Mg-Gd-Y-Zn-Zr Alloy Containing LPSO with Different Morphologies
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作者 Rui Guo Xi Zhao +3 位作者 Bo-Wen Hu Xue-Dong Tian Qiang Wang zhi-min zhang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2023年第10期1680-1698,共19页
In this study,hot compression behavior of as-homogenized Mg-9Gd-4Y-2Zn-0.5Zr alloys containing long period ordered(LPSO)phases with different initial morphologies was investigated under a strain rate of 0.01 s−1 at 45... In this study,hot compression behavior of as-homogenized Mg-9Gd-4Y-2Zn-0.5Zr alloys containing long period ordered(LPSO)phases with different initial morphologies was investigated under a strain rate of 0.01 s−1 at 450°C.The microstructure,texture evolution and dynamic recrystallization(DRX)mechanism under different strains(0.1,0.3,0.5,0.7,and 1.4)were studied.Under compression conditions,the block-shape phase and deformedα-Mg matrix were regularly arranged vertically in the compression direction(CD).The particle phase(Mg5RE)and amount of kink bands were produced.The degree of kink increased initially and decreased significantly when the deformation strain reached 1.4.Three DRX mechanisms were produced during the compression process:(i)The block LPSO,Mg5RE and Zr-Zn phase activated DRX through the particle stimulated nucleation(PSN)mechanism.(ii)Several DRX activated on the serrated grain boundary between the two parent grains through discontinuous DRX(DDRX)mechanism.(iii)A large number of kink bands and larger spacing of lamellar LPSO increased the nucleation of DRX through continuous DRX(CDRX)mechanism.The combination of different recrystallization mechanisms has evident effects on grain refinement.DRX increased as compression proceeds,and the texture was gradually weakened. 展开更多
关键词 Mg-Gd-Y-Zn-Zr alloy Compression Long period ordered(LPSO)phase Recrystallization mechanism
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An Efficient Network-on-Chip Router for Dataflow Architecture 被引量:6
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作者 Xiao-Wei Shen Xiao-Chun Ye +6 位作者 Xu Tan Da Wang Lunkai zhang Wen-Ming Li zhi-min zhang Dong-Rui Fan Ning-Hui Sun 《Journal of Computer Science & Technology》 SCIE EI CSCD 2017年第1期11-25,共15页
Dataflow architecture has shown its advantages in many high-performance computing cases. In dataflow computing, a large amount of data are frequently transferred among processing elements through the network-on-chip ... Dataflow architecture has shown its advantages in many high-performance computing cases. In dataflow computing, a large amount of data are frequently transferred among processing elements through the network-on-chip (NoC). Thus the router design has a significant impact on the performance of dataflow architecture. Common routers are designed for control-flow multi-core architecture and we find they are not suitable for dataflow architecture. In this work, we analyze and extract the features of data transfers in NoCs of dataflow architecture: multiple destinations, high injection rate, and performance sensitive to delay. Based on the three features, we propose a novel and efficient NoC router for dataflow architecture. The proposed router supports multi-destination; thus it can transfer data with multiple destinations in a single transfer. Moreover, the router adopts output buffer to maximize throughput and adopts non-flit packets to minimize transfer delay. Experimental results show that the proposed router can improve the performance of dataflow architecture by 3.6x over a state-of-the-art router. 展开更多
关键词 multi-destination ROUTER NETWORK-ON-CHIP dataflow architecture high-performance computing
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Infl uence of Heat Treatment on Precipitation Behavior and Mechanical Properties of Extruded AZ80 Magnesium Alloy 被引量:5
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作者 Xi Zhao Fa-Fa Yan +2 位作者 zhi-min zhang Peng-Cheng Gao Shu-Chang Li 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2021年第1期54-64,共11页
By means of annular channel angular extrusion technology and solution treatment,the AZ80 supersaturated solid solu-tion was prepared.Theβ-Mg 17 Al 12 precipitate morphologies analysis along with its sizes and area fr... By means of annular channel angular extrusion technology and solution treatment,the AZ80 supersaturated solid solu-tion was prepared.Theβ-Mg 17 Al 12 precipitate morphologies analysis along with its sizes and area fraction measurement was performed to investigate mechanical properties variation of alloy at various aging temperature.The results indicated that after solution treatment,the intergranular precipitate of as-extruded alloy was re-dissolved into the matrix,eff ectively decreasing the stress concentration,which was benefi cial to the enhancement of elongation.At aging temperatures of 300°C,Widmanstatten structure,lath-shaped precipitate,and intergranular precipitate were observed,while at 175–200°C,cellular structure and oval-shaped particle were also identifi ed.The morphology,area fraction,size of the precipitates,and PFZs(precipitate free zones)width worked together to aff ect the age-hardening behavior of the alloy.The strength and hardness of the peak-aged samples decreased with the increase in aging temperature,which is primarily attributed to the reduction in cellular structure area fraction and the corresponding increase in the interlamellar spacing,and the coarsening of the rhombus precipitate. 展开更多
关键词 AZ80 mg alloy Annular channel angular extrusion Heat treatment PRECIPITATE Mechanical properties
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A Non-Stop Double Buffering Mechanism for Dataflow Architecture 被引量:4
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作者 Xu Tan Xiao-Wei Shen +6 位作者 Xiao-Chun Ye Da Wang Dong-Rui Fan Lunkai zhang Wen-Ming Li zhi-min zhang zhi-min Tang 《Journal of Computer Science & Technology》 SCIE EI CSCD 2018年第1期145-157,共13页
Double buffering is an effective mechanism to hide the latency of data transfers between on-chip and off-chip memory. However, in dataflow architecture, the swapping of two buffers during the execution of many tiles d... Double buffering is an effective mechanism to hide the latency of data transfers between on-chip and off-chip memory. However, in dataflow architecture, the swapping of two buffers during the execution of many tiles decreases the performance because of repetitive filling and draining of the dataflow accelerator. In this work, we propose a non-stop double buffering mechanism for dataflow architecture. The proposed non-stop mechanism assigns tiles to the processing element array without stopping the execution of processing elements through optimizing control logic in dataflow architecture. Moreover, we propose a work-flow program to cooperate with the non-stop double buffering mechanism. After optimizations both on control logic and on work-flow program, the filling and draining of the array needs to be done only once across the execution of all tiles belonging to the same dataflow graph. Experimental results show that the proposed double buffering mechanism for dataftow architecture achieves a 16.2% average efficiency improvement over that without the optimization. 展开更多
关键词 non-stop double buffering dataflow architecture high-performance computing
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NATURAL SUPERCONVERGENT POINTS OF EQUILATERAL TRIANGULAR FINITE ELEMENTS - A NUMERICAL EXAMPLE 被引量:3
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作者 zhi-min zhang Ahmed Naga 《Journal of Computational Mathematics》 SCIE CSCD 2006年第1期19-24,共6页
A numerical test case demonstrates that the Lobatto and the Gauss points are not natural superconvergent points of the cubic and the quartic finite elements under equilateral triangular mesh for the Poisson equation.
关键词 Finite element method SUPERCONVERGENCE Triangular mesh Equilateral
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On a Nonparametric Estimator for the Finite Time Survival Probability with Zero Initial Surplus
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作者 zhi-min zhang Hai-liang YANG Hu YANG 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2016年第3期739-754,共16页
In this paper, we consider the estimation of the finite time survival probability in the classical risk model when the initial surplus is zero. We construct a nonparametric estimator by Fourier inversion and kernel de... In this paper, we consider the estimation of the finite time survival probability in the classical risk model when the initial surplus is zero. We construct a nonparametric estimator by Fourier inversion and kernel density estimation method. Under some mild assumptions imposed on the kernel, bandwidth and claim size density, we derive the order of the bias and variance, and show that the estimator has asymptotic normality property. Some simulation studies show that the estimator performs quite well in the finite sample setting. 展开更多
关键词 finite time survival probability fourier transform KERNEL BIAS variance asymptotic normality
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