ICP-AES法测定高碳高铬蓖条中的锰、铝和钛

本文应用ＩＣＰ－ＡＥＳ法同时测定高碳高铬蓖条中锰、铝和钛。用稀硫酸分解样品,滴加硝酸破坏碳化物,水溶解盐类,本方法简单、快速、测定结果准确、相对标准偏差ＲＳＤ〈２．２４％。     

Microstructure of the Ni binder phase in a TiC–Mo2C–Ni cermet

Cermets are wear resistant materials used in cutting tool applications. The materials are composed of hard phase grains surrounded by a tough binder phase. The mechanical properties are influenced by both phases and grain boundaries. In this work, the detailed microstructure of the Ni binder phase in a TiC–Mo₂C–Ni cermet has been studied using a combination of transmission electron microscopy techniques. A complex contrast was observed in the Ni binder when imaged in the transmission electron microscope. It was found to arise from a combination of dislocations and nanometer sized particles that were present in the Ni matrix. From electron diffraction the particles were identified as intermetallic Ni₃Ti (P6₃/mmc). This result was consistent with energy-dispersive microanalysis and thermodynamics. The orientation relationship between the hexagonal Ni₃Ti particles and the cubic Ni matrix was given by (0001)Ni₃Ti//(111)Ni and Ni₃Ti// Ni.     

包头矿的拉曼光谱

本文报道了我国发现的一种含大量Ba、Ti和Nb的硅酸盐类新矿物－包头矿的拉曼光谱特征,着重讨论了拉曼光谱带的归属问题,确定了包头矿中钛氧八面体和硅氧四面体的主要拉曼光谱的振动频率,进一步为包头矿的矿物学增添了谱学新资料。     

Bi_2Ti_2O_7/Si薄膜的制备及C-V特性研究

采用化学溶液分解法 (CSD)在Si衬底上制备了Bi2 Ti2 O7薄膜 .X射线双晶衍射和原子力显微镜检测表明 ,所制备的薄膜主要为Bi2 Ti2 O7相的多晶材料 .同时还研究了Au Bi2 Ti2 O7 n Si(10 0 )结构的电容 电压 (C V)特性 ,结果表明 ,在Bi2 Ti2 O7薄膜中同时存在固定的与可移动的负电荷 ,可移动的负电荷导致了C V曲线的回线效应     

Tunable Sum Frequency Mixing of a Ti:sapphire Laser and a Nd:YAG Laser

In this paper the theoretical and experimental results of sum-frequency mixing of a Ti:sapphire laser and a 1.064 μm Nd:YAG laser are presented. By using two KTP crystals cut at θ=76° and 85° (φ=90° in both crystals), respectively, the sum-frequency mixing tuning range from 459.3 to 509.6 nm in one Ti:sapphire laser setup is experimentally achieved. The maximum output energy was 14.6 mJ and the energy conversion efficiency was up to 15.2%.     

飞秒紫外激光脉冲振荡的实验研究

本文讨论了采用空间光脉冲光谱的啁啾特性和选择聚焦透镜焦距相结合的技术大大提高二次谐波转换效率和产生紫外飞秒光脉冲的实验研究.采用一类相位匹配的BBO晶体,当飞秒钛宝石光脉冲平均功率为560mW时,二次谐波输出功率为352mW,二次谐波转换效率高达63%;采用一类相位匹配的LBO晶体时,获得高光束质量的倍频蓝光输出,输出平均功率为170mW,转换效率大于30%.运用LBO倍频产生的蓝光脉冲和剩余的基频光脉冲进行了三次谐波的振荡研究.三倍频晶体采用BBO,通过优化设计倍频光与基频光之间的空间模匹配及精确时间延迟,得到飞秒紫外光输出,输出功率为2mW,中心波长约为280nm,重复率为100MHz.     

Sn0.5Ti((0.5)O2固溶体的溶胶-凝胶法制备、表征及其热稳定性研究

采用溶胶-凝胶法制备了Sn_0.5Ti_0.5O₂固溶体.用X射线衍射(XRD)、差热分析(DTA)和红外(IR)技术对材料的结构和热稳定性进行了分析表征.固溶体的热稳定性与起始反应温度有关,在40℃水浴温度下制备的凝胶经1000℃烧结,发生了相分解,出现了富Sn和富Ti相,而在80℃水浴温度下制备的凝胶经1200℃烧结也不发生相分解,仍以Sn_0.5Ti_0.5O₂相存在,而且用差热分析也得到了同样的结论.     

锰/磷、钛/磷二元团簇的激光溅射产生与光解

利用激光溅射法直接产生了锰/磷、钛/磷二元团簇正、负离子MxPy±(M=Mn、Ti),并用串级飞行时间质谱仪研究了团簇离子的组成与激光光解规律.实验表明钛与磷间成簇的能力强于锰与磷间成簇的能力,且MPy+(M=Ti、Mn)团簇离子系列表现出峰强度随所含磷原子数目的奇偶性变化,这可能与P4结构的特殊稳定性有关.激光光解实验表明,失去中性P2、P4的通道为主要光解通道.随着团簇离子的生长,锰/磷团簇正离子逐渐由富磷簇向富金属簇过渡,钛/磷则趋向于形成钛原子数目与磷原子数目接近相等的团簇正离子,而二者与磷形成的团簇负离子MxPy-(M=Mn、Ti)逐渐趋向于x≈y,随样品中磷含量增加,锰/磷易形成富磷簇,钛/磷的组成趋向不改变.     

Monomer-Dimer Equilibrium of Rhodamine B Encapsulated in Si–Al and Si–Ti Binary-Oxide Thin Films

Si—Al and Si—Ti binary-oxide thin films including Rhodamine B (RB) have been prepared. They were dip-coated as a function of time after mixing of each sol-gel reaction system. The absorption and fluorescence spectra of the individual films have been observed. These spectra were analyzed in order to clarify the behavior of RB along with the change in the environment around the RB molecules, caused by the progress of the sol-gel reaction, in the fluid sol and the prepared thin films. Some amount of the RB dimers (H- and J-types) were formed in the Si—Al and Si—Ti binary-oxide films (Si : M = 75 : 25) prepared at the initial stage of the sol-gel reaction and aged under relative humidity of 60%. In the case of Si—Al binary-oxide films, the amount of the J-dimer decreased along with the reaction time at which the films were prepared, indicating that growing polymer networks of metal alkoxides around the RB molecules prevent the formation of the J-dimer. On the other hand, larger amounts of the H- and J-dimers were formed in the Si—Ti binary-oxide films prepared at longer reaction time of the solution. RB interacts more strongly with —TiOH compared with —AlOH. In the case of the Si—Ti binary-oxide films, with the progress of the sol-gel reaction, RB molecules in the prepared films easily cohere around the —TiOH and form the dimers because of increase in the amount of the —TiOH and contraction in the volume of the spaces where RB molecules exist.     

手性噁唑啉-Ti((Ⅳ)配合物催化硫醚的不对称氧化反应研究

设计合成了系列:唑啉-Ti(OiPr)₄配合物催化剂,首次成功地用这类催化剂催化一系列硫醚的不对称氧化,获得了e.e.值为70%～96%的亚砜;考察了溶剂、催化剂用量、抗衡离子等因素对反应的影响.