Synthesis and Characterization of a New Polymer-Based Supramolecular Recognition Material and its Adsorption for Cesium

A novel macroporous polymer-based 25,27-bis(iso-propyloxy)calix[4]arene-26,28-crown-6 (BiPCalix[4]C6) supramolecular recognition material, BiPCalix[4]C6/XAD-7, was synthesized. It was performed by vacuum impregnation and immobilization of BiPCalix[4]C6 into the pores of the macroporous XAD-7 particles. The composition and structure were characterized using SEM, BET, TG-DSC, FT-IR, and XRD, respectively. The adsorption of some typical metals contained in highly active liquid waste (HLW) such as Ru(III), Mo(VI), K(I), Rb(I), Cs(I), Sr(II), Ba(II), La(III), and Y(III) onto the BiPCalix[4]C6/XAD-7 materials was investigated. The effects of the HNO₃ concentration and contact time on the adsorption of the tested metals were evaluated. It was found that at the optimum concentration of 4.0 M HNO₃, BiPCalix[4]C6/XAD-7 exhibited excellent adsorption ability and high selectivity for Cs(I) over all the other tested metals, which showed weak or almost no adsorption except Rb(I). It demonstrated that application of the polymer-based supramolecular recognition material, BiPCalix[4]C6/XAD-7, in partitioning of Cs(I) from HLW is promising.     

微光管GaAs阴极激活铯源材料放气成分质谱分析

运用四极质谱计对微光管GaAs阴极激活铯源材料除气时释放的残气进行分析，发现受污染铯放气成分主要是C，CO，CO2，CxHy等残气，它们是使GaAs阴极灵敏度低的主要原因。通过对铯源除气工艺改进，实现了原子级纯净铯获得。并研制出了主要性能合格的微光夜视成像器件。     

Viscosity and thermal conductivity of alkali metal vapors at temperatures up to 2000 K

New experimental data were obtained on transport coefficients of alkali metals in gaseous phase at high temperatures and within the pressure range from about 10 to about 100 kPa: lithium—thermal conductivity, T= 1400–1800 K, and viscosity, T=1600–2000 K; sodium-viscosity, T= 1100–1500 K; and cesiumviscosity, T=900–1250 K. Viscosity of the alkali metal vapors has been measured using a stationary-technique viscometer with an annular gap. Thermal conductivity was measured by the method of the nonstationary monotonous heating. Experimental data were used as a basis for computing effective atomatom and atom-molecule collision cross section, the values obtained from data on viscosity being in good agreement with those derived from thermal conductivity data. In the case of lithium, the atom-atom cross sections yielded by experiments are fairly consistent with the results of calculations with exact formulae of kinetic theory on the basis of quantum-mechanical potential curves for atom-atom interactions. This has enabled the authors to compile consistent tables of viscosities and thermal conductivities for lithium in a gaseous phase within the temperature range from 800 to 2500 K and pressures from 0.5 to 800 kPa, including the saturation curve.     

Viscosity and thermal conductivity of binary eutectics of alkali metals in the vapor phase

Values calculated for the dynamic viscosity and thermal conductivity are presented for vapors of binary eutectics of the alkali metals at temperatures from 800 to 1500 K and at pressures from 100 to 8×10⁵ Pa. Data are presented for the vapors of the systems Li + Na, Na + Rb, Na + Cs, K + Rb, K + Cs, Na + K, and Rb + Cs. The values of the concentrations of the five components in the vapor phase of each binary eutectic are also presented. The accuracy of the calculated viscosities is estimated to be within 4–5% and the accuracy of the calculated thermal conductivities is estimated to be within 8–10%.     

Low-Thermal-Expansion Properties of Sodium- and Lithium-Substituted Cubic Cesium Leucite Compounds

Cubic cesium leucite-based compounds, namely cesium leucites, cesium sodium leucites, and cesium lithium leucites, were synthesized using a multistep solid-state reaction method. The thermal expansion properties, in the temperature range of 298-1273 K, for the synthesized cubic cesium leucite-based compounds were examined using high-temperature powder X-ray diffractometry data. The thermal expansions of the cubic cesium leucite-based compounds were found to vary with the chemical composition. For instance, the thermal expansions of Cs_0.7Na_0.2Al_0.9Si_2.1O₆ and Cs_0.7Li_0.2Al_0.9Si_2.1O₆ were 0.14% at 1273 K and 0.081% at 1073 K, values lower than those of Cs_0.9Al_0.9Si_2.1O₆, which were 0.16% at 1073 K and 0.2% at 1273 K. The results showed that the thermal expansions of the cubic cesium leucite-based compounds changed with ionic substitution at the Cs⁺ sites because of ionic size differences between Cs⁺ and the Na⁺ or Li⁺ substitutional ions.     

Dawson结构磷钨酸铯的制备、表征及催化绿色合成己二酸

利用室温沉淀法制备出Dawson结构磷钨酸铯,考察了其在催化微波促进30%H2O2氧化环己酮合成己二酸反应中的催化性能,并通过FT-IR、SEM、XRD、EDS、ICP-AES对催化剂进行表征。探讨了铯离子取代个数、催化剂用量、微波功率、反应温度、反应时间、H2O2用量等对己二酸收率的影响。结果表明,最优的反应条件为Cs离子取代个数为3,w(催化剂)=7.6%(基于环己酮质量),n(环己酮)∶n(30%H2O2)=100∶375,反应时间4.0 h,微波功率300 W,反应温度100℃。在此条件下己二酸收率可达90.4%。催化剂重复使用5次,己二酸收率为73.1%。     

海洋重磁勘探仪器简介

东方地球物理公司综合物化探事业部于2004年、2005年先后引进了先进的海洋重磁勘探仪器——L＆RS-Ⅱ型海洋重力仪和G-882型海洋磁力仪。经过多年的实际应用与探索,目前已形成了较完善的海洋重磁勘探技术。本文主要介绍L8LRS-Ⅱ重力仪及G-882磁力仪两套仪器的软硬件设备及使用、维护技术。     

MIS／IL硅太阳电池耐紫外辐射性能的研究

通过比较蒸发铯和浸渍铯在ＭＩＳ／ＩＬ硅太阳电池中所引入的铯量、固定正电荷量、界面态密度和对太阳电池表面面电阻的影响，以及测量上述诸量和太阳电池的主要参数经紫外辐照后的变化，并从表面能带的角度分析了引入铯对太阳电池的紫外辐射稳定性的影响，解释了在ＭＩＳ／ＩＬ硅太阳电池中引入铯使该器件耐紫外辐射性能提高的原因。     

改性超稳Y沸石负载的杂多酸铯盐在草莓酯合成反应中的催化性能

制备了一系列以脱铝超稳Y沸石(DUSY)为载体的磷钨酸(PW)及其铯盐催化剂,考察了催化剂在以乙酰乙酸乙酯和1,2-丙二醇为原料催化合成草莓酯反应过程中的性能。结果表明,在负载量(质量分数)为30%的Cs2.5H0.5PW/DUSY催化剂上的乙酰乙酸乙酯的转化率最高,达到95.3%,草莓酯的选择性为100%。得到了适宜的反应条件:反应温度363K,n(乙酰乙酸乙酯)∶n(1,2-丙二醇)=1∶1.5,催化剂占反应体系的质量分数为0.8%,带水剂环己烷占反应体系的质量分数为36%。经过5次反复使用后,负载型磷钨酸铯盐催化剂的催化活性仍较高,转化率达88.2%,而相应的负载型磷钨酸催化剂的催化活性却大幅度下降,转化率仅有31.2%。催化剂活性下降的主要原因是在极性反应体系中杂多酸化合物活性组分流失,而负载型磷钨酸铯盐良好的稳定性源于其难溶脱性。