元素Ti对贮氢合金ZrMn0．7V0．2CO0．1Ni1．2相结构和电化学性能的影响

研究了元素Ti对贮氢电极合金ZrMn0.7V0.2Co0.1Ni1.2的相结构、相组成以及电化学性能的影响。结果表明，对于合金Zr1-xTix(Mn0.7V0.2Co0.1Ni1.2)，其母体合金的主相为C15型Laves相，并含有少量的非Laves相Zr7M10；但随着掺Ti量的增加，合金中出现C14型Laves相，而且其含量逐渐增加；在x=0．1～0．2时，合金中还出现少量的TiNi相，而在x=0．4～0．5时，非Laves相Zr7M10和TiNi相全部消失，说明元素Ti大量的掺杂抑制了第二相的产生：而且随着Ti含量的增加，合金中的C15型和C14型Laves相的晶格常数逐渐减小。电化学测试结果发现，当含Ti量x=0．2时，合金有最大放电容量Cmax为354mAh／g，在放电电流为300mAh／g条件下，高倍率放电性能比母体合金提高了15％。     

温度与初始压力对Zr_9Ni_(11)合金吸氢性能的影响(英文)EI北大核心CSCD

通过定容变压法研究了不同温度(25～150℃)与初始压力(10～160 kPa)对Zr9Ni11合金吸氢性能的影响。氢化实验结果表明,随着温度的升高,Zr9Ni11合金平衡压力明显升高,但吸氢量随之降低。当温度低于75℃时,Zr9Ni11合金初始吸氢速率随温度升高而增大,而当温度高于75℃时,初始吸氢速率随温度升高而降低。初始氢气压力对合金动力学性能影响显著,初始氢气压力低于50 kPa时,合金吸氢速率随初始压力增长而急剧增加,并且在初始氢气压力较低时,仍能快速吸氢。合金吸氢量与平衡压力也随初始氢气压力增加而增大。XRD与TEM分析表明,合金在吸氢前主要为Zr9Ni11相,吸放氢循环后,变为混晶,同时存在非晶态。SEM分析显示,合金在氢化过程中表面粗糙化并出现大量裂痕。研究表明,Zr9Ni11合金可以作为除氚的备选材料。     

Study on the Performances of Nickel Hydroxide Coated with Ytterbium Hydroxide at High-Temperature

在氢氧化镍表面包覆氢氧化镱和氢氧化钴并用XRD、XPS、SEM和恒电流充放电技术进行表征。结果表明:β-Ni(OH)2为六方晶型,Co的存在形式主要为Co2+及有少量的Co3+。样品表面Co和Ni原子比大于8:1。65℃下0.2、1和3C恒电流充放电时,表面包覆2%Yb(OH)3的样品放电容量和活性物质利用率最大。65℃时经过30次充放电循环后,在不同的充放电倍率下,表面包覆不同量Yb(OH)3的氢氧化镍的放电循环稳定性和放电容量随着Yb(OH)3含量的增加而增大。     

表面包覆Yb(OH)_3的Ni(OH)_2正极材料的高温性能研究(英文)

在氢氧化镍表面包覆氢氧化镱和氢氧化钴并用XRD、XPS、SEM和恒电流充放电技术进行表征。结果表明:β-Ni(OH)2为六方晶型,Co的存在形式主要为Co2+及有少量的Co3+。样品表面Co和Ni原子比大于8:1。65℃下0.2、1和3C恒电流充放电时,表面包覆2%Yb(OH)3的样品放电容量和活性物质利用率最大。65℃时经过30次充放电循环后,在不同的充放电倍率下,表面包覆不同量Yb(OH)3的氢氧化镍的放电循环稳定性和放电容量随着Yb(OH)3含量的增加而增大。     

氢化Ti-Zr-Ni准晶和近晶体中的局域结构

氢化处理使二十面体准晶Ti4 5Zr38Ni1 7中的氢比金属 (H/M )达到 0 84、 1 2、1 5 6和 1 7;使 1/ 1近晶体 (W相 )Ti56Zr35Ni1 5中H/M达到 1 2和 1 4。Ti、Ni、Zr的K边的扩展X射线吸收精细结构谱(EXAFS)研究了氢对准晶和W相局域结构的影响。归一化和扣除背底的标准操作用于测定EXAFS振荡X与光电子波矢K的关系。对不同样品的测量结果表明 :有相H/M值 ( 0或 1 2 )的准晶和W相样品的谱线看起来十分相似 ,而未氮化样品与氮化样品(即使H/M为 0 84的低氢样品 )的谱线差别很大 ,其总的趋势是 ;H/M值越大 ,EXAFS振荡向低K方向移动…     

化学镀Ni-Co-P合金对贮氢电极电化学性能的影响

研究了化学镀Ni Co P镀层对贮氢合金电极性能的影响。研究表明 ,引入 1 .74%Co的Ni Co P合金镀层可有效地提高负极贮氢合金活性物质的利用率 ,MH电极的活化性能得到明显改善 ,初次放电容量即达到 2 0 8mA·h/g、最大放电容量达 2 95.8mA·h/g ;同时循环寿命亦有所提高 ,化学镀Ni Co P合金的贮氢电极在进行 1 0 0次循环充放后 ,电容量的保持率为 88% ,而未镀贮氢电极电容量衰减至 62 %。镀Ni Co P合金电极容量的增加 ,主要是由于Co氧化电流和微电流集流效率改善双重作用的结果。化学镀后贮氢合金的抗粉化和抗氧化能力得以改善 ,使得MH电极在自放电性能上有较大改进 ,不可逆部分的容量损失由 2 3.2mA·h/g降到了 3.6mA·h/g。借助于SEM和XRD分析了化学镀Ni Co P合金对MH电极性能改善的影响机理。     

工艺参数对直流磁控溅射膜沉积的影响

在为进一步了解工艺参数对溅射膜沉积的影响,开展了不同工作气体压强、不同溅射功率和有无负偏压条件下的Zr、Cu、Ni单金属溅射膜和Zr—Cu、Zr-Ni二元合金溅射膜的溅射沉积实验。使用称重法,分析了溅射膜沉积量随工作气体压强、溅射功率的变化规律;通过分层溅射和共溅工艺实验,对比了相同溅射功率下Zr与Cu、Zr与Ni元素间分层溅射膜和共溅膜的沉积量;采用扫描电子显微镜,分析、研究了溅射过程中负偏压对Cu溅射膜膜层生长方式的影响。结果表明,由于工作气体压强对电子与气体分子以及对靶材原子与气体分子碰撞几率的影响,使得膜层的沉积量不是随着工作气体压强的升高单纯地呈下降趋势,而是有一最佳压强范围;随着溅射功率的增大,膜层沉积量增加,在溅射功率相等的条件下,由于辉光放电电场叠加增大了工作气体的离化率,使得共溅膜比分层溅射膜的沉积量大得多;溅射过程中施加较高负偏压可以抑制柱状结构生长,细化晶粒,提高膜层致密度。     

碳酰胺与氢化锆高温下原位反应层的AES/XPS分析

采用碳酰胺高温分解产生含C、O、N源与氢化锆原位反应制备阻氢渗透层,借助俄歇电子能谱(AES)和X射线光电子能谱(XPS)等手段对阻氢渗透层元素成分及深度、键态进行分析。AES结果表明:氢化锆表面原位反应层由C、N、O、Zr元素组成,随溅射时间增加,O、Zr元素含量增加,C、N元素含量降低。原位反应层厚度约3.4μm,其中含N、C层深度约150 nm。氢化锆表面阻氢渗透层XPS分析表明,表面层存在ZrO_2,同时有Zr-OH、Zr-N、C-H、N-H键。氢在扩散过程中被C、O、N捕获表明含C、O、N的氢化锆表面原位反应层对氢的渗透有一定的阻碍作用。     

快速凝固Ti-Zr-Ni合金的电化学贮氢性能

采用铜辊快速凝固方法制备了Ti45Zr30Ni25和Ti50Zr25Ni25合金,并对合金作为镍-氢二次电池负极的动力学和电化学性能进行了研究.结果表明,Ti45Zr30Ni25为非晶相合金,Ti50Zr25Ni25合金由准晶相和非晶相组成.两合金电极的最大放电容量分别为129和132mAh/g.在240mA/g电流密度下,高倍率放电性能(HRD)分别为62.7%和63.3%.合金电极的交换电流密度分别为205.1和375.6mA/g,氢在合金中的扩散系数分别为5.4×10-11和5.8×10-11cm2·S-1.     

采用WC过渡层增加金刚石薄膜附着力的研究

在微波等离子体化学气相沉积装置中，以WC-8％Co为基体，采用氢等离子体脱碳、磁控溅射镀W、碳化等方法，制备了微晶WC过渡层。研究了金刚石薄膜与基体的附着力。结果表明，表面脱碳后再镀W膜，W填充了氢等离子体脱碳时刀具表面因钴蒸发而留下的空洞，形成过渡层，在随后的碳化中和基体WC连接较为紧密，能增加金刚石薄膜与基体附着力，克服单纯的氢等离子体脱碳还原法降低刀具基体硬度、不能完全消除钴的有害影响的缺点。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.     

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.