二氧化碳碳化法制备氧化镧粉体研究

对二氧化碳直接碳化制备氧化镧粉体进行了研究,以氯化镧溶液和二氧化碳为原料,通过调控反应体系pH值制备获得稀土碳酸盐,再经过焙烧得到粒径小、粒度分布窄的氧化镧粉体。研究表明:在不同反应温度和pH条件下,通过碳化法可以获得不同形貌的前驱体,其中控制反应温度为25℃,pH为5的条件下,可以获得片状碳酸镧前驱体;经XRD,FI-IR,TG-DSC分析表征,确定该前驱体化学组成为La2(CO3)3·3.2H2O;通过焙烧可获得中值粒径D50为4.75μm,粒度分布(D90-D10)/(2×D50)<1.00的氧化镧粉体。二氧化碳碳化法制备氧化镧粉体技术具有条件温和、产品粒径小、粒度分布窄、易规模化生产的优点,而且可以实现二氧化碳循环利用以减少温室效应。     

Synthesis of mesoporous silica-alumina materials via urea-templated sol-gel route and their catalytic performance for THF polymerization

A series of mesoporous silica-alumina materials was successfully synthesized by using urea as a low-cost template via sol-gel routes. The characterization results showed that the employ of urea enhanced the porosity of the silica-alumina materials and made the pore size distributions become narrower. The specific surface area, pore volume and pore diameter of SAU-X firstly increased and then decreased as the urea concentration increased from 0 to 60 wt %, and the maximums were obtained at 40 wt % urea concentration. All samples were tested for the THF polymerization. Among them, SAU-40 exhibited the highest activity and the longest catalyst life due to its superior porosity.     

Magneto‐Plasmonic Janus Vesicles for Magnetic Field‐Enhanced Photoacoustic and Magnetic Resonance Imaging of Tumors

Magneto‐plasmonic Janus vesicles (JVs) integrated with gold nanoparticles (AuNPs) and magnetic NPs (MNPs) were prepared asymmetrically in the membrane for in vivo cancer imaging. The hybrid JVs were produced by coassembling a mixture of hydrophobic MNPs, free amphiphilic block copolymers (BCPs), and AuNPs tethered with amphiphilic BCPs. Depending on the size and content of NPs, the JVs acquired spherical or hemispherical shapes. Among them, hemispherical JVs containing 50 nm AuNPs and 15 nm MNPs showed a strong absorption in the near‐infrared (NIR) window and enhanced the transverse relaxation (T₂) contrast effect, as a result of the ordering and dense packing of AuNPs and MNPs in the membrane. The magneto‐plasmonic JVs were used as drug delivery vehicles, from which the release of a payload can be triggered by NIR light and the release rate can be modulated by a magnetic field. Moreover, the JVs were applied as imaging agents for in vivo bimodal photoacoustic (PA) and magnetic resonance (MR) imaging of tumors by intravenous injection. With an external magnetic field, the accumulation of the JVs in tumors was significantly increased, leading to a signal enhancement of approximately 2–3 times in the PA and MR imaging, compared with control groups without a magnetic field.     

Synthesis and electrochemical properties of substituted heteropoly acid with Dawson structure H7[In(H2O)P2W17O61]·23H2O

A new solid high-proton conductor, substituted heteropoly acid with Dawson structure H(7)[In(H(2)O)P(2)W(17)O(61)]·23H(2)O, has been synthesized by the degradation/ion exchange/freezing method. The pH of the synthesis reaction was given. The product was characterized by chemical analysis, IR, UV, XRD and TG-DTA. The determination of conductivity shows that H(7)[In(H(2)O)P(2)W(17)O(61)]·23H(2)O is an excellent solid high-proton conductor with conductivity of 1.34 × 10(-3) S cm(-1) at 18 °C, and 70% relative humidity (RH). Its activation energy is 37.72 kJ mol(-1), which suggests that its mechanism of proton conduction is the Vehicle mechanism.     

Geodesic orbit metrics on compact simple Lie groups arising from flag manifolds

In this paper, we investigate left-invariant geodesic orbit metrics on connected simple Lie groups, where the metrics are formed by the structures of flag manifolds. We prove that all these left-invariant geodesic orbit metrics on simple Lie groups are naturally reductive.     

电子学全息法再现三维物场

叙述了一种采用电子学全息法分析三维物场的定量方法，它包括：（１）三维物场全息图的数字记录，２）全息图面上复振幅分布的数字再现，（３）利用空间频域衍射公式计算其它平面上的复振幅分布，由此可以获得整个三维物场的信息。本文同时还给出这一数字再现方法的空间分辨率。最后通过计算机模拟展示了一个理想三维物场的再现过程及再现结果。     

燃料油超深度脱硫：二苯并噻吩在改性活性炭上的吸附

Ultra-deep desulfurization of fuel oils is used for producing clean fuels to meet new emission control standards, and also for producing sulfur-free hydrogen for use in fuel cell systems, where the hydrogen is produced by the reforming of fuel oils[1～2].     

超痕量铑的催化动力学分析研究

在氯化钠存在的磷酸介质中，铑（Ⅲ）对高碘酸钾氧化罗丹明Ｂ裉色的反应具有强烈的催化作用，该催化反应对罗丹明Ｂ和铑（Ⅲ）均为一级反应，反应的表观活化能为６８．３８ｋＪ／ｍｏｌ。以该反应为指示反应建立的动力学光度法可测定０．０３－２．５ｎｇ／２５ｍｌ的铑，考察了３０多种离子的干扰情况，本法选择性好。     

以还原褪色反应催化光度法测定痕量钒

本文在氯化钠存在下的柠檬酸－柠檬酸钾缓冲溶液中，以钒（Ｖ）催化次磷酸钠还原罗丹明Ｂ褪色为指示反应，建立了痕量钒的动力学光度分析新方法，在９０℃水浴中恒温反应１０ｍｉｎ测定钒的线性范围为０～４．０μｇ／Ｌ，回归方程为△Ａ＝０．１８６３Ｃｖ＋０．００３７，ｒ＝０．９９９５。该法灵敏度高，选择性好，直接应用于水样和合金钢样中钒的测定，取得了满意的结果。