Al＋Ti＋C复合系热爆反应合成过程及相组成研究EI

研究了Ａｌ含量和Ｃ／Ｔｉ对Ａｌ＋Ｔｉ＋Ｃ复合系热爆反应合成Ａｌ／ＴｉＣ的反应过程及生成相组成的影响。实验结果表明：随着Ａｌ含量的增加，反应温度降低，反应时间延长，但反应起始温度几乎没有变化；Ｃ／Ｔｉ对反应温度和反应时间有很大的影响，但对反应起始温度影响很小。在对生成相组成的研究中发现：当Ｃ／Ｔｉ＝１．２５、Ａｌ含量不大于６０ａｔ％和Ｃ／Ｔｉ＝１、Ａｌ含量不大于５０ａｔ％时，生成物只有ＴｉＣ；随着Ａｌ含量的增加，生成Ａｌ＿３Ｔｉ的量增加，并通过热力学理论对反应合成自由能进行了计算，计算结果与试验结果相吻合。另外，通过扫描电子显微镜（ＳＥＭ）对生成的ＴｉＣ的组织形貌进行了观察。结果表明：生成的ＴｉＣ尺寸均匀，约为０．３～０．８μｍ，大多数呈球状，部分为块状。     

铝含量对自生TiCp/2024复合材料的影响

用真空热爆－加压工艺制备了高颗粒含量了ＴｉＣｐ／２０２４复合材料,通过通过采集了记录了不同铝含量时热爆反应的时间－温度曲线,通过ＸＲＤ分析了ＴｉＣｐ／２０２４复合材料的相组成,用扫描电镜分析了ＴｉＣｐ的分布和形貌,结果表明,随着Ａｌ含量的增加,起始反应时间延长,最高反应温度和反应速度降低,当Ａｌ含量小于６５ｗｔ％时反应生成ＴｉＣｐ,当Ａｌ含量大于６５ｗｔ％时除了反应生成ＴｉＣｐ外,还存在的ＴｉＡｌ     

Al含量对热爆反应合成Al／TiC复合材料的影响

本文利用热爆反应合成法制备了Ａｌ／ＴｉＣ复合材料，研究了反应合成过程中，温度特性以及Ａｌ含量对其的影响，结果表现：在反应合成过程中的Ａｌ的熔化，然后是陶瓷相的合成反应，并且随着Ａｌ含量的增加，反应最高温度降低，而反应起始温度和反应持续时间基本不变。此外，研究了Ａｌ含量对反应生成 影响。     

Ti-Al-C系热爆反应制备TiC/Al复合材料的研究

以Ｔｉ，Ａｌ，Ｃ粉末为原料，用热爆反应法制备了原位ＴｉＣ颗粒增强的ＴｉＣ／Ａｌ的Ａｌ基复合材料。研究了Ｔｉ－Ａｌ－Ｃ系热爆合成过程，探讨了热爆合成ＴｉＣ粒子的形成机制。研究表明：生成的ＴｉＣ粒子呈球形，尺寸均匀，且随体系中含Ａｌ量的增加，热爆反应合成ＴｉＣ的温度降低，ＴｉＣ颗粒尺寸减小。     

Ti—Al—C系热爆反应制备TiC／Al复合材料的研究

以Ｔｉ，Ａｌ，Ｃ粉末为原料，用热爆反应制备了原位ＴｉＣ颗粒增强的ＴｉＣ／Ａｌ的Ａｌ基复合材料。研究了Ｔｉ－Ａｌ－Ｃ系热爆合成过程，探讨了热爆合成ＴｉＣ粒子的形成机制，研究表明，生成了ＴｉＣ粒子呈球形，尺寸均匀，且随体系中含Ａｌ量的增加，热爆反应合成ＴｉＣ的温度降低，ＴｉＣ颗粒尺寸减小。     

TiAl基合金中的不连续粗化转变

为细化铸造ＴｉＡｌ基合金的显微组织,将成分为Ｔｉ－４４．９Ａｌ、Ｔｉ－４８Ａｌ以及Ｔｉ－４４．３Ａｌ－３．０Ｃｒ（ａｔ％）的三种合金在略高于Ｔｉ－Ａｌ共析温度的１１５０℃进行长时保温处理。结果表明,保温一定时间后,合金中的Ｔｉ３Ａｌ＋ＴｉＡｌ片层组织会发生三种类型的不连续粗化转变,转变结果均能在一定程度上细化合金的铸态晶粒尺寸,其中Ｔｉ－４４．３Ａｌ－３．０Ｃｒ合金的晶粒细化效果最佳。此外,Ａｌ含量的增加,合金元素Ｃｒ的加入等都会大大促进合金的不连续经转变过程。     

TiAl及TiC／TiAl合金的XD合成研究

本文研究了用ＸＤ工艺合成ＴｉＡｌ合金及ＴｉＣ／ＴｉＡｌ复合材料，研究结果表明，可在Ａｌ的熔点附近用ＸＤ工艺制备ＴｉＡｌ合金及其ＴｉＣ颗粒增强复合材料。ＴｉＡｌ合金由ＴｉＡｌ＋Ｔｉ３Ａｌ相组成，而ＴｉＣ／ＴｉＡｌ复合材料由ＴｉＣ＋ＴｉＡｌ＋Ｔｉ３Ａｌ相组成。     

Fe-Ti-C系燃烧合成反应的热力学分析

利用相图计算技术（ＣＡＬＰＨＡＤ）对Ｆｅ－Ｔｉ－Ｃ燃烧合成反应体系进行热力学分析,着重研究Ｆｅ含量和Ｃ／Ｔｉ原子比对体系绝热燃烧温度Ｔ_ａｄ和平衡相组成的影响．研究结果表明,Ｆｅ含量对 Ｆｅ－Ｔｉ－Ｃ三元系的平衡相组成影响不大,但对绝热燃烧温度的影响非常大．当保持Ｃ／Ｔｉ原子比接近１．０时,不管Ｆｅ含量如何变化;在２９８Ｋ下均会得到理想的平衡相组织ＴｉＣ＋Ｆｅ 随Ｆｅ含量增加,体系的绝热燃烧温度大致呈线性降低．Ｆｅ－Ｔｉ－Ｃ体系发生ＳＨＳ反应的热力学条件之一（Ｔ_ａｄ＞１８００Ｋ）是Ｆｅ＜５５ｗｔ％．而 Ｃ／Ｔｉ原子比对绝热燃烧温度的影响比较小,但对平衡相组成影响非常大,主要表现在两个方面：①石墨相的析出温度不同．随Ｃ／Ｔｉ原子比降低,析出温度也随之降低．②在各温区石墨相的含量不同．当 Ｃ／Ｔｉ在１．０～１．４变化时,石墨相含量在低温区由１％提高到１６％．     

Li1+2x+yAlxNdyTi2-x-ySixP3-xO12系统的锂快离子导体研究

Ｌｉ１＋２ｘ＋ｙＡｌｘＮｄｙＴｉ２－ｘ－ｙＳｉｘＰ３－ｘＯ１２锂快离子导体可以用精选的天然高岭石Ａｌ４「Ｓｉ４Ｏ１０」（ＯＨ）８为起始原料，经与Ｌｉ２Ｃｏ３、ＴｉＯ２、ＮＨ４Ｈ２ＰＯ４进行高温（８００－１０００℃固相反应约２０ｈ而制得，一个空间群属于Ｒ３Ｃ的固溶体导电相可在ｙ＝０．５，ｘ≤０．３和ｙ＝１．０，ｘ≤０．４的组成范围内发现，该盯具有较好的电导性较低的活化能，起始组成ｙ＝１．０，ｘ＝０．     

Al-Ti-TiO2体系燃烧合成及其反应过程研究

利用Ａｌ－Ｔｉ－ＴｉＯ_２体系放热反应,采用自蔓延高温合成工艺。原位合成了ＴｉＡｌ基体和Ａｌ_２Ｏ_３颗粒,成功制备出ＴｉＡｌ／Ａｌ_２Ｏ_３复合材料．结合差热分析,通过对不同温度下反应产物相组成分析;对Ａｌ－Ｔｉ－ＴｉＯ_２体系燃烧反应过程进行了初步研究．结果表明,铝热还原反应是一个分步过程,先期发生的Ａｌ－Ｔｉ、Ｔｉ－ＴｉＯ_２反应降低了Ａｌ－ＴｉＯ_２还原反应的起始温度．     

Mechanochemical fabrication of C (matrix) + Cu + Si + W + Mo nanocomposites

Using magnesiothermic reduction of WO₃, MoO₃, SiO₂, and CuO through mechanochemical activation, we prepared high-purity (∼99.3%) nanopowders with a particle size from 9 to 350 nm for the fabrication of functional materials and nanocomposite systems for anode electrodes of lithium ion (polymeric) batteries.     

Measurement of solubility and density of water + lithium bromide + lithium chloride and water + lithium bromide + sodium formate systems

Solubility of aqueous solutions containing lithium bromide + lithium chloride and lithium bromide + sodium formate were measured (LiBr/NaHCO₂ = 2 and LiBr/LiCl = 2 by mass ratio) at different temperatures. Visual polythermal method was used in the temperature range of (283.15–340.15) K and mass fraction range of (0.4–0.8). Also density of mentioned systems was reported in the temperature range of (288.15–333.15) K. Each set of experimental measurements were correlated using least-square regression as a function of temperature. Our results indicate that solubility of LiBr + LiCl is higher than LiBr and its density is lower than density of aqueous solution of LiBr.     

Electrical characterization of Si+ and Si+/P+ implanted N+P+In0.53Ga0.47As junctions

In this communication, we present I–V and admittance spectroscopy measurements of shallow n⁺p junctions into p-InGaAs made by Si⁺ implantation, including a complete study of the conduction mechanisms as a function of temperature. The effect of P⁺ co-implantation is also analysed. The I–V characteristics of both junctions show that recombination in the space-charge zone is the dominant transport mechanism in forward bias, with ideality factors around 1.5 at 300 K that increase with decreasing temperature of measurement. Activation energies of the reverse saturation current are obtained at room temperature, being 0.5 eV and 0.4 eV for Si⁺ and Si⁺P⁺ implanted diodes, respectively, indicating that recombination currents occur through a near midgap center. Reverse current–voltage measurements show a higher conduction in the P⁺ co-implanted junction due to a higher concentration of traps. In both types of junctions, the reverse characteristics can be fitted to a thermally-activated trap-assisted tunneling mechanism at low bias, involving traps at 0.41 eV and 0.44 eV for Si⁺ and P⁺ co-implanted junctions, respectively, whereas different trap-assisted tunneling processes dominate at medium and high bias. The small signal analysis show a clear difference between the two types of junctions. The use of Kramers–Kronig transforms on the admittance spectroscopy data reveals the presence of a defect level at 0.35 eV in both types of junctions, probably assigned to Zn, the native acceptor present in the p-InGaAs. Another trap level at 0.30 eV is detected at the P⁺ co-implanted junctions, not appearing in the Si doped junctions, which could probably be due to damage produced by the co-implantation.     

Phase Composition of the Products of Fe Oxidation in Fe + C + NaCl + H2O + O2 Exothermic Mixtures

Using thermodynamic analysis of the Fe–C–NaCl–H₂O–O₂ system and experimental studies (x-ray diffraction and Mössbauer spectroscopy) of exothermic mixtures containing Fe metal, activated carbon, water, and NaCl, we identified the state of Fe and determined the phase composition of the reaction products at different stages of oxidation with atmospheric oxygen. The calculation and experimental results are in reasonable agreement. Under the conditions of restricted access for air, the main oxidation product is magnetite, Fe₃O₄. Free access for air leads to the formation of hydrous ferric oxide, Fe₂O₃ · nH₂O. The most stable phase under the conditions of interest is goethite, Fe₂O₃ · H₂O (-FeOOH). Storage of incompletely oxidized samples away from air for 7–14 days leads to partial reduction of iron(III) oxide phases to Fe₃O₄ and -Fe.     

(Sr2+,Bi3+,Si4+,Ta5+)掺杂的TiO2压敏陶瓷中Ta5+的研究

研究Ta2 O5对 (Sr,Bi,Si,Ta)掺杂的TiO2 基压敏陶瓷压敏特性及电容特性的影响 ,发现按配方TiO2 0 .3%(SrCO3 Bi2 O3 SiO2 ) 0 .1 %Ta2 O5配制的样品具有最低压敏电压 (E1 0mA =1 .2V·mm- 1 )、最大相对介电常数 (εra=2 .0 0 2× 1 0 5)及较小非线性系数 (α =2 .6 )。考虑到材料的低压敏电压和大介电常数的要求 ,Ta2 O5最佳掺杂量在 0 .0 85mol%与 0 .1mol%之间。     

（Sr^2＋，Bia^3＋，Si^4＋，Ta^5＋）掺杂的TiO2压敏陶瓷中Ta^5＋的研究

研究Ta2O5对(Sr,Bi,Si,Ta)掺杂的TiO2基压敏陶瓷压敏特性及电容特性的影响,发现按配方TiO2+0.3%(SrCO3+Bi2O3+SiO2)+0.1%Ta2O5配制的样品具有最低压敏电压(E10mA=1.2V·mm-1)、最大相对介电常数(εra=2.002×105)及较小非线性系数(a=2.6).考虑到材料的低压敏电压和大介电常数的要求,Ta2 O5最佳掺杂量在0.085mol%与0.1mol%之间.     

Ionic conductivity of potassium antimonate tungstates with partial Na+ or Li+ substitution for K+

We have studied the formation of monovalent metal antimonate tungstates by solid-state reactions in the xM₂CO₃ · (y ? x)K₂CO₃ · ySb₂O₃ · 2(2 ? y)WO₃ (M = Na, Li; 0 ≤ x ≤ y; 1.0 ≤ y ≤ 2.0) systems and identified the stability regions of pyrochlore phases at a temperature of 1123 K in the KSbO₃-WO₃-MSbO₃ (M = Na, Li) composition triangles. A model has been proposed for the ion distribution over the sites of the pyrochlore structure (sp. gr. Fd3m). The conductivity of the monovalent metal antimonate tungstates has been measured in the temperature range 500–1000 K, and a relationship between their ionic conductivity and structure has been established.     

新西兰JAG CREATIVE:品牌、营销与推广

为这个真实世界进行品牌与平面设计创作就是新西兰Jag Creative品牌设计公司的热情。作为一个岛国,新西兰的企业在创新与创造性方面有着令人惊叹的杰出表现。     

Solubilities, Vapor Pressures, and Heat Capacities of the Water + Lithium Bromide + Lithium Nitrate + Lithium Iodide + Lithium Chloride System

The optimum mole ratio of lithium salts in the H₂O + LiBr + LiNO₃ + LiI + LiCl system was experimentally determined to be LiBr : LiNO₃ : LiI : LiCl = 5 : 1 : 1 : 2. The solubilities were measured at temperatures from 252.02 to 336.75 K. Regression equations on the solubility data were obtained with a least-squares method. Average absolute deviations of the calculated values from the experimental data were 0.15% at temperatures <285.18 K and 0.05% at temperatures 285.18 K. The vapor pressures were measured at concentrations ranging from 50.0 to 70.0 mass% and at temperatures from 330.13 to 434.88 K. The experimental data were correlated with an Antoine-type equation, and the average absolute deviation of the calculated values from the experimental data was 2.25%. The heat capacities were measured at concentrations from 50.0 to 65.0 mass% and temperatures from 298.15 to 328.15 K. The average absolute deviation of the values calculated by the regression equation from the experimental data was 0.24%.     

高密度发光材料γ-Bi2WO6:Pr3+的发光性质研究

研究了用固相法制备的高密度发光材料γ-Bi2WO6Pr3+的结构、光致发光光谱、激发谱和γ-Bi2WO6的漫反射谱.由实验测得它的晶格参数为a=5.45A,b=16.42A,c=5.43A,密度Dx=9.53g/cm3.它的光致发光光谱主发射峰位于600、608、611、629nm,分别来自于pr3+的1D2→3H4、3P0→3H5、3P0→3H6、3P0→3F2跃迁的发射.其激发谱由位于约225～430nm范围内、最大值约在372nm的主激发带和450nm的激发峰组成;主激发带来自于基质,可能是基质的带间吸收、W-O间电荷迁移吸收和缺陷能级的吸收;450nm的激发峰来自于pr3+的3H4→3P2跃迁吸收.BWOPr3+的最佳掺杂浓度为0.8mol%左右.