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序贯性精细化康复护理在踝关节骨折患者中的应用价值
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作者 周思敏 《中文科技期刊数据库(文摘版)医药卫生》 2024年第10期0168-0171,共4页
讨论在踝关节骨折患者中应用序贯性精细化康复护理时对病情康复产生的积极影响。方法 纳入50例踝关节骨折患者,参与研究时间为2021年8月-2023年8月,随机分组方法为分层抽样法,以每组25例的标准划分为研究组与对照组。常规护理模式、常... 讨论在踝关节骨折患者中应用序贯性精细化康复护理时对病情康复产生的积极影响。方法 纳入50例踝关节骨折患者,参与研究时间为2021年8月-2023年8月,随机分组方法为分层抽样法,以每组25例的标准划分为研究组与对照组。常规护理模式、常规护理模式基础上实施序贯性精细化康复护理分别实施于对照组、研究组,观察踝关节症状、活动度、功能、相关并发症。结果 踝关节症状干预前组间比较后差距性较小,P>0.05;但是该项症状在干预3个月后以研究组各评分指标较对照组更低,P<0.05。踝关节活动度干预前组间比较后差距性较小,P>0.05;但是该肢体活动度指标在干预3个月后以研究组各评分指标较对照组更低,P<0.05。研究组相关并发症发生率的4%较对照组更低P<0.05。踝关节功能干预前组间比较后差距性较小,P>0.05;但是该项功能在干预3个月后以研究组各评分指标较对照组更好,P<0.05。结论 序贯性精细化康复护理在踝关节骨折患者中的应用实施可促使其踝关节症状、活动度、功能改善,并有助于减少不良并发症,具有显著临床应用价值。 展开更多
关键词 踝关节骨折 序贯细化康复护理 常规护理
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混凝土抗冻性概念的细化及其测评方法 被引量:7
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作者 陈立军 王德君 +4 位作者 张丹 孔令炜 韩莹 关国英 荣华 《新型建筑材料》 北大核心 2009年第9期8-10,共3页
强调了不同环境条件下混凝土抗冻性概念的区别,并探讨了它们之间的相互关系及其测试方法。指出不同环境条件下混凝土抗冻性会随着混凝土孔结构的变化而发生变化。评价混凝土的抗冻性时,应针对不同的环境条件,采取不同的模拟试验和评价... 强调了不同环境条件下混凝土抗冻性概念的区别,并探讨了它们之间的相互关系及其测试方法。指出不同环境条件下混凝土抗冻性会随着混凝土孔结构的变化而发生变化。评价混凝土的抗冻性时,应针对不同的环境条件,采取不同的模拟试验和评价方法。 展开更多
关键词 混凝土 抗冻概念细化 环境条件 测评方法
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Strength and plasticity improvement induced by strong grain refinement after Zr alloying in selective laser-melted AlSiMg1.4 alloy
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作者 Yao-xiang GENG Chun-feng ZAI +3 位作者 Jiang YU Hao TANG Hong-wei LÜ Zhi-jie ZHANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期2733-2742,共10页
In order to enhance the mechanical properties of the selective laser-melted(SLM) high-Mg content AlSiMg1.4 alloy,the Zr element was introduced.The influence of Zr alloying on the processability,microstructure,and mech... In order to enhance the mechanical properties of the selective laser-melted(SLM) high-Mg content AlSiMg1.4 alloy,the Zr element was introduced.The influence of Zr alloying on the processability,microstructure,and mechanical properties of the alloy was systematically investigated through performing microstructure analysis and tensile testing.It was demonstrated that the SLM-fabricated AlSiMg1.4-Zr alloy exhibited high process stability with a relative density of over 99.5% at various process parameters.Besides,the strong grain refinement induced by the primary Al3Zr particle during the melt solidification process simultaneously enhanced both the strength and plasticity of the alloy.The values for the yield strength,ultimate tensile strength,and elongation of the SLM-fabricated AlSiMg1.4-Zr were(343±3) MPa,(485±4) MPa,and(10.2±0.2)%,respectively,demonstrating good strengthplasticity synergy in comparison to the AlSiMg1.4 and other Al-Si-based alloys fabricated by SLM. 展开更多
关键词 selective laser melting process stability grain refinement microstructure mechanical properties
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Laser processing effects on Ti−45Nb alloy surface,corrosive and biocompatible properties
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作者 I.CVIJOVIĆ-ALAGIĆ S.LAKETIĆ +5 位作者 M.MOMČILOVIĆ J.CIGANOVIĆ Đ.VELJOVIĆ J.BAJAT V.KOJIĆ M.RAKIN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第8期2533-2551,共19页
The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatme... The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatment,(Ti,Nb)O scale was formed and various morphological features appeared on the alloy surface.The electrochemical behavior of Ti−45Nb alloy in simulated body conditions was evaluated and showed that the alloy was highly resistant to corrosion deterioration regardless of additional laser surface modification treatment.Nevertheless,the improved corrosion resistance after laser treatment was evident(the corrosion current density of the alloy before laser irradiation was 2.84×10^(−8)A/cm^(2),while that after laser treatment with 5 mJ was 0.65×10^(−8)A/cm^(2))and ascribed to the rapid formation of a complex and passivating bi-modal surface oxide layer.Alloy cytotoxicity and effects of the Ti−45Nb alloy laser surface modification on the MRC-5 cell viability,morphology,and proliferation were also investigated.The Ti−45Nb alloy showed no cytotoxic effect.Moreover,cells showed improved viability and adherence to the alloy surface after the laser irradiation treatment.The highest average cell viability of 115.37%was attained for the alloy laser-irradiated with 15 mJ.Results showed that the laser surface modification can be successfully utilized to significantly improve alloy performance in a biological environment. 展开更多
关键词 Ti−45Nb alloy laser surface scanning electrochemical properties BIOCOMPATIBILITY cell morphology
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基于低秩矩阵恢复的视觉显著性目标检测与细化 被引量:1
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作者 周静波 黄伟 《控制与决策》 EI CSCD 北大核心 2021年第7期1707-1713,共7页
基于低秩矩阵恢复(low-rank matrix recovery,LRMR)的显著性目标检测模型将图像特征分解为与背景关联的低秩分量和与显著性目标相关联的稀疏分量,并从稀疏分量中获得显著性目标.现有的显著性检测方法很少考虑低秩分量与稀疏分量之间的... 基于低秩矩阵恢复(low-rank matrix recovery,LRMR)的显著性目标检测模型将图像特征分解为与背景关联的低秩分量和与显著性目标相关联的稀疏分量,并从稀疏分量中获得显著性目标.现有的显著性检测方法很少考虑低秩分量与稀疏分量之间的相互关系,导致检测的显著性目标零散或不完整.为此,提出基于低秩矩阵恢复的显著性目标检测与细化方法来规避该限制.首先,所提方法采用?1范数稀疏约束和拉普拉斯正则项对初始显著图进行计算;在显著性细化阶段,由于非局部的?0优化可以有效地对显著性区域及其邻接区域之间的相互关系进行建模,结合初始显著图,采用非局部?0梯度优化,最小化显著性区域中显著值的变化,从而保证显著性目标的完整性.在4个显著性目标检测数据集上进行实验,通过实验结果验证所提算法的优越性. 展开更多
关键词 显著目标检测 低秩矩阵恢复 ?0优化 显著性细化 稀疏矩阵
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Microstructure and mechanical properties of AZ61 magnesium alloy prepared by repetitive upsetting-extrusion 被引量:11
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作者 徐岩 胡连喜 +3 位作者 孙宇 贾建波 姜巨福 马庆国 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期381-388,共8页
The process of repetitive upsetting-extrusion (RUE) was used to achieve severe plastic deformation (SPD) for an as-cast AZ61 magnesium alloy in temperature range of 285-380 ℃. The microstructure and mechanical pr... The process of repetitive upsetting-extrusion (RUE) was used to achieve severe plastic deformation (SPD) for an as-cast AZ61 magnesium alloy in temperature range of 285-380 ℃. The microstructure and mechanical properties of the as-cast and RUE processed AZ61 alloys were investigated. The results indicated that homogeneous fine-grained structure with mean grain size of 3.5 μm was obtained as the accumulated true strain in the axial direction increased to 4.28 after three RUE passes at 285 ℃. The dominant reason of grain refinement was considered the dynamic recrystallization induced by strain localization. It was also found that the microstructural evolution was affected by temperature and accumulated deformation. The mechanical properties of RUE processed AZ61 alloys were significantly improved owing to grain refinement. Furthermore, the relationship between deformation parameters and mechanical properties of AZ61 alloy prepared by RUE processing was revealed by tensile tests carried out at room temperature. 展开更多
关键词 AZ61 magnesium alloy repetitive upsetting-extrusion severe plastic deformation groin refinement mechanicalproperties
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Structure uniformity and limits of grain refinement of high purity aluminum during multi-directional forging process at room temperature 被引量:6
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作者 朱庆丰 李磊 +3 位作者 班春燕 赵志浩 左玉波 崔建忠 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第5期1301-1306,共6页
The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinemen... The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinement limitation with very high strains. The results show that the fine grain zone in the center of sample expands gradually with the increase of forging passes. When the forging passes reach 6, an X-shape fine grain zone is initially formed. With a further increase of the passes, this X-shape zone tends to spread the whole sample. Limitation in the structural refinement is observed with increasing strains during multi-forging process at the room temperature. The grains size in the center is refined to a certain size (110 μm as forging passes reach 12, and there is no further grain refinement in the center with increasing the forging passes to 24. However, the size of the coarse grains near the surface is continuously decreased with increasing the forging passes to 24. 展开更多
关键词 multi-directional forging high purity aluminum structure uniformity grain refinement
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Improving in plasticity of orthorhombic Ti_2AlNb-based alloys sheet by high density electropulsing 被引量:6
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作者 宋辉 王忠金 赫晓东 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期32-37,共6页
In order to optimize the ductility of orthorhombic Ti2AlNb-based alloys sheet,Ti22Al27Nb sheet was treated by high density electropulsing(J max =6.80 7.09 kA/mm2,tp =110 μs) under ambient condition.Microstructures ... In order to optimize the ductility of orthorhombic Ti2AlNb-based alloys sheet,Ti22Al27Nb sheet was treated by high density electropulsing(J max =6.80 7.09 kA/mm2,tp =110 μs) under ambient condition.Microstructures were observed by SEM,and the tensile properties were also studied using uniaxial tension tests.The experimental results show that electropulsing can refine the microstructures of Ti22Al27Nb sheets.The specimen with the fine and homogeneous microstructures has good plasticity,and its elongation reaches 19.4%.The mechanism about the effect of electropulsing treatment on the microstructure of Ti22Al27Nb sheets was discussed.It was thought that the increase in nucleation rate during phase transformation and a very short treating time were regarded as the main reasons of producing smaller grains and increase in the plasticity by electropulsing. 展开更多
关键词 Ti2AlNb-based alloys electropulsing treatment PLASTICITY grain refinement microstructure nucleation rate phase transformation
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Microstructure and properties of plasma remelted AZ91D magnesium alloy 被引量:5
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作者 崔洪芝 孟兆涛 +2 位作者 肖成柱 孙金全 王翠香 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第1期30-35,共6页
The surface of AZ91 D magnesium alloy was remelted by plasma beam. The microstructure, composition, hardness, wear and corrosion resistance of the plasma remelted layer(PRL) were characterized. The results show that... The surface of AZ91 D magnesium alloy was remelted by plasma beam. The microstructure, composition, hardness, wear and corrosion resistance of the plasma remelted layer(PRL) were characterized. The results show that there is extremely fine and dendrite structure in the PRL at low magnification observation, which is still composed of α-Mg and β-Mg17Al12 phases. But at high magnification observation, the microstructure of the PRL is equiaxial crystalline grains with size of 3-5 μm. And also the content of α-Mg phase decreases while that of β-Mg17Al12 increases and distributes more uniformly in α-Mg matrix compared with the substrate. The hardness of the PRL is much higher than that of the substrate. There are plastic deformation, grains uprooting and tearing evidence with tiny even dimples in the tensile fracture of the PRL, which are different from the substrate. Furthermore, the surface wear and corrosion resistance of AZ91 D are improved significantly after plasma remelting. 展开更多
关键词 magnesium alloy plasma remelting solid solution strengthening refined crystalline strengthening wear resistance corrosion resistance
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Effects of Cu addition on microstructure and mechanical properties of as-cast magnesium alloy ZK60 被引量:5
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作者 朱红梅 罗承萍 +1 位作者 刘江文 焦东玲 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第3期605-610,共6页
The effects of Cu addition on the microstructure and mechanical properties of the as-cast magnesium alloy ZK60 were investigated with optical microscope, SEM, TEM, XRD, EPMA and tensile tester. The mechanism by which ... The effects of Cu addition on the microstructure and mechanical properties of the as-cast magnesium alloy ZK60 were investigated with optical microscope, SEM, TEM, XRD, EPMA and tensile tester. The mechanism by which the mechanical properties are affected by Cu addition was discussed. The results show that Cu can effectively eliminate the intragranular solute segregations in the alloy, and the grain size of the alloy is decreased considerably with increasing the Cu amount. A ternary eutectic phase MgZnCu with a face-centered cubic structure is identified in the Cu-bearing alloys, which predominantly distributes at the grain boundary and acts as the nucleation sites of microcracks during the plastic deformation process. It is also found that the tensile properties of the alloy firstly increase by the trace addition of 0.5%-1%Cu and then decrease by a further addition up to 2.0%. 展开更多
关键词 ZK60 magnesium alloy Cu addition MgZnCu phase grain refinement mechanical properties
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Microstructure and mechanical properties of GTA weldments of titanium matrix composites prepared with or without current pulsing 被引量:2
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作者 毛建伟 吕维洁 +2 位作者 王立强 张荻 覃继宁 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第5期1393-1399,共7页
The effects of current pulsing on the microstructure, hardness and tensile properties at different temperatures of gas tungsten arc (GTA) weldments of titanium matrix composites were studied. Full-penetration butt j... The effects of current pulsing on the microstructure, hardness and tensile properties at different temperatures of gas tungsten arc (GTA) weldments of titanium matrix composites were studied. Full-penetration butt joints were made with or without current pulsing. Optical microscopy, hardness test and scanning electron microscopy were employed to evaluate the metallurgical characteristics of welded joints. Tensile properties of weldments at different temperatures were studied and correlated with the microstructure. The results exhibit that current pulsing leads to the refinement of the weld microstrucmre and TiB whisker and the redistribution of reinforcements resulting in higher hardness, tensile strength and ductility of weldments in the as-welded condition. 展开更多
关键词 titanium matrix composites pulsed current WELDING mechanical properties grain refinement microstructure
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Ultrastructural Features of Nucleus Degradation During Programmed Cell Death of Starchy Endosperm Cells in Rice 被引量:2
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作者 韦存虚 蓝盛银 徐珍秀 《Acta Botanica Sinica》 CSCD 2002年第12期1396-1402,共7页
Ultrastructural features of nucleus degradation during programmed cell death (PCD) of starchy endosperm cells in rice ( Oryza sativa L.) were observed using transmission electron microscopy. Several distinct morpho... Ultrastructural features of nucleus degradation during programmed cell death (PCD) of starchy endosperm cells in rice ( Oryza sativa L.) were observed using transmission electron microscopy. Several distinct morphological features of PCD have been found in the developing starchy endosperm cells, e.g. nucleus deformation, chromatin condensation, nuclear envelope disruption, and nuclear matrix leakage. DNA ladder displayed a smear of large DNA fragments from nucleus and evident bands of small DNA fragments (140-180 bp) from both nucleus and cytoplasm. In contrast with the rapid nucleus degradation, cell organelles in cytoplasm, such as rough endoplasmic reticulum, amyloplast, and mitochondrion, maintained their metabolic functions for a longer time. Seed reserves were continually synthesized and accumulated in the starchy endosperm cells despite the nucleus degradation during the PCD process. These results suggest that starchy endosperm cells remain active during reserve material synthesis and accumulation in the PCD process. The specific relationships between nucleus and cytoplasm in the developing endosperm cells and the morphological changes of nucleus in the endosperm PCD process were also discussed. 展开更多
关键词 RICE starchy endosperm cell nucleus degradation programmed cell death
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Microstructure refinement of a dual phase titanium alloy by severe room temperature compression 被引量:1
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作者 张志强 董利民 +3 位作者 杨洋 关少轩 刘羽寅 杨锐 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2604-2608,共5页
Microstructure refinement of a dual phase titanium alloy, Ti-3AI-4.5V-5Mo, by severe room temperature compression was investigated. Nanocrystalline grains were observed in the sample with 75% reduction, in which the g... Microstructure refinement of a dual phase titanium alloy, Ti-3AI-4.5V-5Mo, by severe room temperature compression was investigated. Nanocrystalline grains were observed in the sample with 75% reduction, in which the grain sizes of a phase and β phase were approximately 50 and 100 nm. Conversely, the average thicknesses of a phase and β phase in as-received microstructure were measured to be 0.7 and 0.5 μm, respectively. TEM and XRD methods were used to analyze the microstructure and texture changes after severe deformation. Microstructure refinement was deduced to the complex interaction among slip dislocations in the a phase, the complex interaction among slip dislocations and martensites in the β phases. In addition, the interaction between the a phase and the β phase also contributed to the microstructure refinement. 展开更多
关键词 dual phase titamum alloy Ti-3AI-4.3V-3Mo alloy severe plastic detormatlon mlcrostructure retinement nanocrystalline grains TEXTURE
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An Antioxidant Acidic Polysaccharide from Cuscuta chinensis 被引量:6
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作者 王展 方积年 《Acta Botanica Sinica》 CSCD 2001年第3期243-248,共6页
An acidic polysaccharide, H2, was isolated from the alkali-extract CHC of seeds of Cuscuta chinensis Lam. with the molecular weight more than 1.0 x 10(6). Chemical and spectroscopic studies led to the structure determ... An acidic polysaccharide, H2, was isolated from the alkali-extract CHC of seeds of Cuscuta chinensis Lam. with the molecular weight more than 1.0 x 10(6). Chemical and spectroscopic studies led to the structure determination as follows: the backbone chain consists of 1, 6-linked-beta -D Galp, 1,4-linked-X -D Galp, 1,4-linked-beta -D GalA and 1,2- or 1,4-linked-beta -L Rhap having branching points at position O-3 of some 1,6-linked-beta -D Galp residues (one among eight) and O-4 or O-2 of 1,2- or 1,4-linked-beta -L Rhap residues to terminal beta -D-galactopyranose. The side chains composed of terminal Galp, 1,6-linked-beta -D Galp, 1,4-linked beta -D Galp and 1,3,6-linked-beta -D Galp also linked at position O-3 of 1,6-linked-beta -D Galp residues in the backbone chain. beta -L-arabinofuranosyl and terminal beta -L-rhamnopyranosyl residues existed in the periphery of this polysaccharide linked to O-3 of 1,6-linked-beta -D Galp residues in the backbone chain and the side chains. The polysaccharide H2 increased significantly the survival rate of PC12 cells indicating that it had protective effects against H2O2 insult. 展开更多
关键词 Cuscuta chinensis Convolvnlaceae POLYSACCHARIDES PC12 cells
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Effects of neodymium addition on microstructure and mechanical properties of near-eutectic Al-12Si alloys 被引量:4
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作者 胡志 阮先明 闫洪 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期3877-3885,共9页
The microstructure and mechanical properties of near-eutectic Al-12 Si alloys modified with 0-0.4% Nd(mass fraction) were investigated. The results indicate that a submicro- or nano-sized Al2 Nd phase is observed in... The microstructure and mechanical properties of near-eutectic Al-12 Si alloys modified with 0-0.4% Nd(mass fraction) were investigated. The results indicate that a submicro- or nano-sized Al2 Nd phase is observed in the modified alloy with 0.3% Nd. The morphology of the α(Al) phase is significantly refined in the Nd-modified alloys. The primary Si morphology simultaneously changes into a fine, particle-like morphology, and the morphology of eutectic Si becomes fine-fibrous instead of coarse-acicular. Relatively few growth twins are observed on the surface of the Si plate in the Al-12Si-0.3Nd alloy at the optimal modification level. The mechanical property test results confirm that the mechanical properties of the as-cast Al-12 Si alloys are enhanced after the Nd addition, with optimal ultimate tensile strength(UTS) of 252 MPa and elongation(EL) of 13% at an Nd content of 0.3%. The improved mechanical properties are attributed to the refined morphology of Si phase and the formation of the Al2 Nd phase. 展开更多
关键词 Al-12Si alloy NEODYMIUM REFINEMENT growth twins mechanical properties
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Ultracytochemical Localization of Acid Phosphatase in Nucellar Cells of Wheat During Degeneration 被引量:6
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作者 田国伟 申家恒 尤瑞麟 《Acta Botanica Sinica》 CSCD 1999年第8期791-794,共4页
The distribution of acid phosphatase activity in nucellar cells of wheat ( Triticum aestivum L.) during degeneration has been studied using the lead precipitation method at the electron microscopic level. Acid phos... The distribution of acid phosphatase activity in nucellar cells of wheat ( Triticum aestivum L.) during degeneration has been studied using the lead precipitation method at the electron microscopic level. Acid phosphatase was localized in the slightly condensed nuclear chromatin in nucellar cells without any sign of ultrastructural degeneration. As the nucellar cells started degenerating, the enzyme activity in the cell was observed, in the order from small vacuoles to cell walls, mitochondria, plastids and endoplasmic reticulum. Enzyme activity was the highest in most components of the nucellar cells adjacent to the embryo sac where the degeneration of nucellar cells was the strongest, but it was not observed in the nuclei of the degenerated nucellar cells. The results indicated that the degeneration of nucellar cells was a progressive and orderly process and supported that the degeneration of nucellar cells was a programmed cell death. 展开更多
关键词 Triticum aestivum Nucellar cell DEGENERATION Acid phosphatase Ultracytochemical localization
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Microstructure and tensile properties of containerless near-isothermally forged TiAl alloys 被引量:4
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作者 贺卫卫 汤慧萍 +3 位作者 刘海彦 贾文鹏 刘咏 杨鑫 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第12期2605-2609,共5页
Ti-47Al-2Nb-2Cr-0.4(W, Mo) (mole fraction, %) alloy ingot fabricated using vacuum consumable melting was containerless near-isothermally forged, and the high temperature forgeability, microstructure and tensile pr... Ti-47Al-2Nb-2Cr-0.4(W, Mo) (mole fraction, %) alloy ingot fabricated using vacuum consumable melting was containerless near-isothermally forged, and the high temperature forgeability, microstructure and tensile properties were investigated. The results show that the TiAl ingot exhibits good heat workability during containerless near-isothermally forging process, and there are not evident cracks on the surface of as-forged TiAl pancake with a total deformation degree of 60%. The microstructure of the TiAl ingot appears to be typical nearly-lamellar(NL), comprising a great amount of lamellar colonies (α2+γ) and a few equiaxed γ grains. After near-isothermally forging, the as-forged pancake shows primarily fine equiaxed γ grains with an average grain size of 20 μm and some broken lamellar pieces, and some bent lamellas still exist in the hard-deformation zone. Tensile tests at room temperature show that ultimate tensile strength increases from 433 MPa to 573 MPa after forging due to grain refinement effect. 展开更多
关键词 TiAl alloy MICROSTRUCTURE tensile property containerless near-isothermal forging grain refinement
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Preparation of Superfine Fe_3O_4 Cubic Powders
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作者 刘颖 高伟 王建华 《Journal of Beijing Institute of Technology》 EI CAS 1993年第1期98-102,共5页
A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder... A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder has a higher H(?) and lower σ,than one made up of spherical Fe_O_4. 展开更多
关键词 ferric oxide MAGNETISM superfine powder
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Constituents from Ranunculus sieboldii Miq. 被引量:7
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作者 潘云雪 周长新 +2 位作者 张水利 郑筱祥 赵昱 《Journal of Chinese Pharmaceutical Sciences》 CAS 2004年第2期92-96,共5页
Aim To investigate the chemical composition of Ranunculus sieboldii Miq..Methods Repeated column chromatography over silica gel, polyamide and RP-18 followed by gelfiltration on sephadex LH-20 were used to isolate che... Aim To investigate the chemical composition of Ranunculus sieboldii Miq..Methods Repeated column chromatography over silica gel, polyamide and RP-18 followed by gelfiltration on sephadex LH-20 were used to isolate chemical constituents, and their structures wereelucidated by extensive spectroscopic methods (UV, IR, MS, ~1H NMR, ^(13)C NMR) including 2D NMR(COSY, HMQC, HMBC, NOESY) techniques and by direct comparing spectral data with those reported inliterature. Results Five flavonoid glycosides named apigenin-4'-O-α-L-rhamnopyranoside (1),apigenin-7-O-β-D-glucopyranosyl-4'-O-α-L-rhamnopyranoside (2), apigenin-8-C-α-L-arabinopyranoside(3), apigenin-8-C-β-D-ga-lactopyranoside (4) , tricin-7-O-β-D-glucopyranoside (5), together withtricin (6), luteolin (7), scopoletin (8), esculetin (9), scoparone (10), ferulic acid (11),protocatechuic acid (12) , and tematolide (13) were isolated from the 95% etha-nolic extract of itswhole plant, and their cytotoxic activities were preliminarily tested. Conclusion Compounds 1-12were obtained from this genus and compound 13 from this species for the first time. Furthermore,compound 1 was for the first time isolated from nature while the ^(13)C NMR data of compounds 2 and3 are reported for the first time. The bioassay revealed that compound 1 was active against BEL-7407and A549 cell lines (IC_(45) 43, 77 μg·mL^(-1)), 8 and 10 showed inhibitory activities on KB celllines (IC_(50) 78, 44 μg·mL^(-1)) and HL-60 cell lines (Ic_(50) 85, 85 μg·mL^(-1)), while 7exerted moderate cytotoxic activities on KB, BFL-7407, A549 and HL-60 cell lines with their IC_(50)being 51, 55, 44 and 10 μg·mL^(-1) , respectively. 展开更多
关键词 ranunculus sieboldii miq. flavonoid glycosides apigemn-4'-O-α-L-rhamnopyranoside apigenin-8-C-α-L-arabinopyranoside apigenin-7-O-β-D-glucopvranosyl-4'-O-α-L-rhamnopyranoside cytotoxicity
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Tuning mechanical properties for β(B2)-containing TiAl intermetallics 被引量:5
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作者 邱从章 刘咏 +4 位作者 黄岚 刘彬 张伟 贺跃辉 黄伯云 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2593-2603,共11页
Based on the analyses of the microstructures and phase diagrams of the TiAl-based alloy, the relationship among the composition, structure and mechanical properties of the B2-containing y-TiAI alloys was reviewed. The... Based on the analyses of the microstructures and phase diagrams of the TiAl-based alloy, the relationship among the composition, structure and mechanical properties of the B2-containing y-TiAI alloys was reviewed. The refinement of microstructures and improvement of mechanical properties of TiA1 alloy through stabilization of the β/B2 phase were reviewed. The mechanism of the superplastic behavior of the B2-containing y-TiAI alloys was discussed. With a reasonable addition of β-stabilizer, metastable B2 phase can be maintained, which is favorable for fine-grained structure and better high-temperature deformation behaviors. The mechanical properties of the B2-containing TiAI alloy, including the deformability and elevated temperature properties, can also be improved with doping elements and subsequent hot-working processes. The above mentioned researches discuss a new way for developing TiAI alloys with comprehensive properties, including good deformability and creep resistance. 展开更多
关键词 β-stabilizing elements B2 phase TiAl-based alloys phase diagram grain refinement thermal processing superplasticdeformation
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