甲烷部分氧化制合成气反应Pt/Al_2O_3和Pt/CeO2/Al_2O_3催化剂的研究(英文)

研究了Ｐｔ／Ａｌ２Ｏ３和Ｐｔ／ＣｅＯ２／Ａｌ２Ｏ３催化剂对甲烷部分氧化制合成气反应的催化活性，发现Ｐｔ／ＣｅＯ２／Ａｌ２Ｏ３显示了比Ｐｔ／Ａｌ２Ｏ３更高的甲烷转化率和合成气选择性。用Ｈ２ＴＰＲ，Ｈ２ＴＰＤ，ＳＥＭ和ＸＲＤ等手段和技术对催化剂进行了表征。ＣｅＯ２与Ｐｔ之间存在较强的相互作用（ＳＭＳＩ），这种作用促进了Ｐｔ在催化剂表面的分散，抑制了Ｐｔ在催化剂表面的迁移，大大降低了催化剂在反应中的完全燃烧活性，提高了催化剂的部分氧化活性和选择性，避免了因催化剂床层局部温度过高而导致催化剂活性下降或失活，提高了催化剂的稳定性。同时，在反应过程中，ＣｅＯ２通过促进水蒸气变换反应（ＷＧＳＲ）的进行使反应体系迅速达到平衡，提高了催化剂对Ｈ２的选择性。     

Copolymerization of toluene with tetrafluoromethane or octafluorocyclobutane by plasma technique

Plasma copolymerization of toluene with tetrafluoromethane or octafluorocyclobutane was carried out in a capacitively coupled tubular reactor with external electrodes. The polymer structure was characterized by means of XPS, IR, and pyrolysis/GC/MS and the condensates of the gases in the plasma reaction chamber were measured by GC–MS. It is observed that the monomers undergo a plasma states polymerization in a glow discharge and only those monomer fragments with sufficient reactivity join the copolymerization. The types of fluorine-containing groups in the polymer structure are related to the chemical structure of the flurocarbons. The fluorine content depends upon the discharge power, the system pressure, and the fraction of fluorocarbons in the monomers     

HYDROGENATION OF CO_2 OVER A YBa_2Cu_3O_(6～7) CATALYST

研究了ＹＢａＣｕ３Ｏ６～７超导催化剂上ＣＯ２的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、ＣＯ和少量甲醚。利用ＸＰＳ、ＸＲＤ和ＡＦＭ等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现，在反应过程中，ＹＢａ２Ｃｕ３Ｏ６～７由ｏｒｔｈｏｍｂｉｃ相转变为ｔｅｔｒａｇｏｎａｌ相。反应活性位可能是Ｃｕ（Ｉ）物种。反应后催化剂颗粒的分散程度明显提高     

Capillary electrophoretic behaviors of pharmacologically active xanthones from Securidaca inappendiculata with beta-cyclodextrin as a buffer additive

The capillary electrophoretic (CE) behaviors of ten xanthones in the presence of beta-cyclodextrin (CD) are investigated, and apparent analyte-selector binding constants between beta-CD and the xanthones in the CE running buffer are calculated to elucidate the migration order. Also, the separation selectivity with beta-CD additive is compared with that of sulfated beta-CD additive. It is indicated that beta-CD can greatly change the separation selectivity of xanthones, and the electrophoretic behaviors of xanthones are rather different when using beta-CD from that when using sulfated beta-CD as an additive.     

通过式固相萃取-超高效液相色谱-串联质谱法测定水产品中地西泮

建立了通过式固相萃取-超高效液相色谱-串联质谱测定水产品中地西泮残留量的分析方法。样品用乙腈直接提取，经Prime HLB通过式固相萃取柱（60 mg/3 mL）净化，以Acquity UPLC BEH C₁₈（100 mm×2.1 mm，1.7 μm）为色谱柱，甲醇-0.1%（v/v）甲酸水溶液为流动相进行梯度洗脱。在多反应监测（MRM）、正离子电离模式下检测，采用基质匹配标准曲线外标法进行定量分析。结果显示：在0.1~10 ng/mL范围内，地西泮线性关系良好（r²>0.99）。在1.5、3.0和15.0 μg/kg 3个加标水平下，地西泮的加标回收率为88.2%~101.1%，日间和日内精密度（RSD）均在10%以下。该法简便快速，灵敏度高，可用于水产品中地西泮的准确测定。     

Mathematical optimization in intensity modulated radiation therapy

The design of an intensity modulated radiotherapy treatment includes the selection of beam angles (geometry problem), the computation of an intensity map for each selected beam angle (intensity problem), and finding a sequence of configurations of a multileaf collimator to deliver the treatment (realization problem). Until the end of the last century research on radiotherapy treatment design has been published almost exclusively in the medical physics literature. However, since then, the attention of researchers in mathematical optimization has been drawn to the area and important progress has been made. In this paper we survey the use of optimization models, methods, and theories in intensity modulated radiotherapy treatment design.     

Spectral characterization and energy levels of Cr:Sc2(MoO4)3 crystal

This paper reports the spectral properties and energy levels of Cr³⁺:Sc₂(MoO₄)₃ crystal. The crystal field strength Dq, Racah parameter B and C were calculated to be 1408 cm⁻¹, 608 cm⁻¹ and 3054 cm⁻¹, respectively. The absorption cross sections σ_α of ⁴A₂→⁴T₁ and ⁴A₂→⁴T₂ transitions were 3.74×10⁻¹⁹ cm² at 499 nm and 3.21×10⁻¹⁹ cm² at 710 nm, respectively. The emission cross section σ_e was 375×10⁻²⁰ cm² at 880 nm. Cr³⁺:Sc₂(MoO₄)₃ crystal has a broad emission band with a broad FWHM of 176 nm (2179 cm⁻¹). Therefore, Cr³⁺:Sc₂(MoO₄)₃ crystal may be regarded as a potential tunable laser gain medium.     

一些连续统的孤立链回归点

对树或图上的连续自映射,本文证明了孤立链回归点是终周期点,如孤立边回归不在临界点的轨道中且它的轨道中也不含有临界点,则它还是周期点,我们还证明了上述性质可以扩张到一类特殊的λ－dendroid上。