电感耦合等离子体原子发射光谱(ICP-AES)法测定高纯铝中Fe、Cu、Mg、Zn、Ti

建立了用电感耦合等离子体原子发射光谱(ICP-AES)法测定高纯铝中Fe、Cu、Mg、Zn、Ti的方法。详细讨论了基体元素和共存元素对分析元素的光谱干扰,以及盐酸用量的影响;选择了合适的分析谱线,同时得出了各元素的检出限。证明用基体匹配的方法在Fe 259.940nm、Cu 327.396nm、Mg279.079nm、Zn 213.856nm、Ti 334.941nm处可准确、可靠地测定高纯铝中含量范围在0.001%~0.01%的Fe、Cu、Mg、Zn、Ti元素。     

基体分离-电感耦合等离子体原子发射光谱法 测定精铋中10种杂质元素

试验采用电感耦合等离子体发射光谱法测定精铋中Cd、Co、Cu、Fe、Mg、Mn、Ni、Pb、Ti、Zn十种杂质元素,样品用优级纯硝酸溶解,往60℃左右的溶液中,滴加氨水(1+1),控制pH值在3.0~4.0。考察了温度、酸度、沉降时间对铋的去除率和对检测结果的影响。根据分析线的选择原则,结合待测元素的检测范围,选择无干扰、峰形对称、灵敏度适中的谱线作为分析线Cd 228.802nm、Co 237.862nm、Cu 324.754nm、Fe 259.940nm、Mg 279.553nm、Mn 257.610nm、Ni 231.604nm、Pb 182.205nm、Ti 323.452nm、Zn 213.856nm。各元素的质量浓度在一定范围内与其发射强度呈线性,校准曲线的线性相关系数均大于0.9997,方法中各元素检出限为0.002μg/g~0.253μg/g。?按照实验方法测定精铋实际样品,结果的相对标准偏差(RSD,n=9)为2.5%~9.8%,加标回收率为95.0%~102.2%,满足检测要求。     

大口径掺钛蓝宝石晶体放大的实验研究

 分析了口径为80 mm的钛宝石晶体内的增益特性,对大口径钛宝石晶体中的泵浦光能量密度和泵浦光口径进行了优化设计。对于80 mm×17 mm的晶体,最佳工作光束口径为55 mm,泵浦能量为50 J;对于80 mm×30 mm的晶体,最佳工作光束口径为60 mm,泵浦能量为90 J,且其横向小信号增益远小于80 mm×17 mm晶体的。对影响大口径钛宝石晶体放大的横向放大自发辐射（ASE）和寄生振荡采用折射率匹配的包边技术进行了抑制。实验表明,该方法把允许横向增益从13提高到了2 100。实验系统为100 J绿光台面泵浦激光器,100 TW主放大器采用四程空间构型放大光路。80 mm×17 mm钛宝石晶体c轴水平放置,泵浦光和主激光均为水平偏振。当以泵浦光能量为49 J对主放大器进行双端泵浦,注入信号光能量为1.2 J,光束口径60 mm时,获得了14.2 J的放大光输出和286 TW的最高峰值功率。     

氢原子在Ti(0001)表面吸附的密度泛函理论研究

用密度泛函理论研究了氢原子的污染对于Ti(0001)表面结构的影响. 通过PAW总能计算研究了p(1×1)、p(1×2)、3^1/2×3^1/2R30[deg]和p(2×2)等几种氢原子覆盖度下的吸附结构, 以及在上述结构下Ti(0001)面fcc格点和hcp格点的氢原子吸附. 结果表明, 在p(1×1)-H、p(1×2)-H、3^1/2×3^1/2R30[deg]-H和p(2×2)-H几种H原子覆盖度下, 以p(1×1)-H结构的单个氢原子吸附能为最大. 在p(1×1)-H吸附结构下, 由于氢原子吸附导致的Ti(0001)表面Ti原子层收缩的理论计算数值分别为-2.85%(hcp吸附)和-4.31%(fcc吸附), 因此实际上最有可能的情况是两种吸附方式都有一定的几率. 而实验中观察到的所谓“清洁”Ti(0001)表面实际上是有少量氢原子污染的表面. 不同覆盖度和氢分压下, 氢原子吸附的污染对Ti(0001)表面结构有极大的影响, 其表面的各种特性都会随覆盖度的不同而产生相应的变化.     

Defect Formation,T-Atom Substitution and Adsorption of Guest Molecules in MSE-Type Zeolite Framework—DFT Modeling

We used computational modeling, based on Density Functional Theory, to help understand the preference for the formation of silanol nests and the substitution of Si by Ti or Al in different crystallographic positions of the MSE-type framework. All these processes were found to be energetically favorable by more than 100 kJ/mol. We suggested an approach for experimental identification of the T atom position in Ti-MCM-68 zeolite via simulation of infrared spectra of pyridine and acetonitrile adsorption at Ti. The modeling of adsorption of hydrogen peroxide at Ti center in the framework has shown that the molecular adsorption was preferred over the dissociative adsorption by 20 to 40 kJ/mol in the presence or absence of neighboring T-atom vacancy, respectively.     

退火对钛/铜热等静压扩散连接界面的影响

钛/铜(Ti/Cu)作为ITER 第一壁Be/CuCrZr 热等静压连接中间过渡层,形成了多层中间金属相结构,容易在Ti/Cu 金属相之间产生裂纹等缺陷。采用CuCrZr 代替Be,经过与Be/CuCrZr 相同的热等静压工艺,制作了多个CuCrZr/Ti/Cu/CuCrZr 连接件,对Ti/Cu 连接接头进行深入分析。对连接件分别进行未退火、400℃和500℃ 退火处理,去应力退火后对接头强度和缺陷分布的影响进行了研究。研究结果表明,中间钛层的两侧都形成了三层Ti/Cu 扩散层,分别为Cu₄Ti、CuTi 和CuTi₂。纯铜侧的Cu₄Ti 厚度比CuCrZr 侧的厚,使得裂纹几乎全部分布于铜侧的Cu₄Ti 与CuTi 交界处,拉伸样品极易在此处发生脆性断裂。随着退火温度升高,裂纹的产生和扩展减少。     

纳米氧化锰负载钛基电催化膜制备及处理含酚废水性能研究

以多孔钛膜为基膜,醋酸锰为锰源,采用溶胶凝胶法制备出负载纳米氧化锰的钛基电催化膜（nano-MnO_x/Ti膜）. 运用X射线衍射(XRD)、 X射线光电子能谱(XPS)、场发射扫描电子显微镜(FESEM)、循环伏安法(CV)、交流阻抗法（EIS）和计时电流法(CA)等测试手段,对MnO_x/Ti膜电极的微观形貌、晶型、电化学性能等进行表征. 结果表明：所得催化剂是由直径为50 nm的γ-MnO₂和Mn₂O₃纳米棒所组成,且均匀分布于Ti膜上,负载催化剂后钛膜电极电化学性能和催化性能明显提高,催化剂与基体之间键合的形成提高其稳定性. 以棒状nano-MnO_x/Ti膜电极为阳极构建电催化膜反应器(ECMR)处理含酚废水,当苯酚溶液浓度为10mmol·L^-1,电流密度为0.25mA·cm^-2、停留时间为15 min时,COD去除率可达95.1%.     

Ag implantation-induced modification of Ni–Ti shape memory alloy thin films

Nanocrystalline thin films of Ni–Ti shape memory alloy are deposited on an Si substrate by the DC-magnetron co-sputtering technique and 120?keV Ag ions are implanted at different fluences. The thickness and composition of the pristine films are determined by Rutherford Backscattering Spectrometry (RBS). X-Ray diffraction (XRD), atomic force microscopy (AFM) and four-point probe resistivity methods have been used to study the structural, morphological and electrical transport properties. XRD analysis has revealed the existence of martensitic and austenite phases in the pristine film and also evidenced the structural changes in Ag-implanted Ni–Ti films at different fluences. AFM studies have revealed that surface roughness and grain size of Ni–Ti films have decreased with an increase in ion fluence. The modifications in the mechanical behaviour of implanted Ni–Ti films w.r.t pristine film is determined by using a Nano-indentation tester at room temperature. Higher hardness and the ratio of higher hardness (H) to elastic modulus (E_r) are observed for the film implanted at an optimized fluence of 9?×?10¹⁵ ions/cm². This improvement in mechanical behaviour could be understood in terms of grain refinement and dislocation induced by the Ag ion implantation in the Ni–Ti thin films.