填充Silicalite—I沸石的PDMS橡胶醇—水分离膜

Ｓｉｌｉｃａｌｉｔｅ－Ｉ沸石经过酸处理或水热处理可完善其晶体结构，提高对乙醇的吸附选择性，由此提高对乙醇－水混合物的分离系数，特别是先经过酸处理再经过水解处理的Ｓｉｌｉｃａｌｉｔｅ－Ⅱ沸石填充聚二甲基硅氧烷橡胶膜，乙醇－水的分离系数可达３０左右。     

Liesegang rings — Part I

Summary The conditions for the formation of revert type ofLiesegang rings have been studied here. Various systems of rhythmic precipitations of silver chromate are produced in a mixtures of agar and gelatin gels under different environmental conditions. Ring systems of silver, copper and other ferricyanides have also been studied in gelatin gel. The observations show that the cause of the revert systems ofLiesegang rings is the high peptizability of the precipitating matter in the media containing gel and the unreacted ions.

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Zusammenfassung Die Bedingungen der Bildung des „umgekehrten“ Types vonLiesegang-Ringen wurden untersucht. Verschiedene Systeme rhythmischer F?llung von Silberchromat wurden in einer Mischung von Agar und Gelatinegelen unter verschiedenen Umgebungsbedingungen erzeugt. Ringsysteme von Kupfer, Silber und anderen Ferricyaniden in Gelatine wurden untersucht. Die Beobachtungen zeigen, da? die Ursache für die „umgekehrten“Liesegang-Ringe in der hohen Peptisierbarkeit der Füllsubstanz im gelhaltigen Medium und den noch nicht reagierten Ionen liegt.

     

天然CXN沸石分子筛水热稳定性研究 I. 水热稳定性影响因素

以天然CXN沸石为基底材料, 通过离子交换、焙烧和酸处理等方法研究了影响该沸石水热稳定性的因素. XRD, XRF和27Al MAS NMR等结果表明阳离子种类和位置均会影响沸石水热稳定性, 其中铵型CXN沸石的水热稳定性最高. 高温焙烧铵型CXN沸石虽能提高骨架硅铝比, 但骨架缺陷增多导致其水热稳定性下降. 还研究了水蒸汽量、处理温度和时间对沸石骨架结构变化的影响, 结果表明提高温度和水蒸汽量均会降低沸石结晶度, 但处理时间则对结晶度的影响较小.     

Die Schwingungsspektren von Mesitylverbindungen—I. Mesitylhalogenide

The infrared and Raman vibrational frequencies of mesitylfluoride, -chloride, -bromide and -iodide are reported and completely assigned to the normal vibrations. The results of a partially successfull normal coordinate analysis are also presented.     

Anti—diabetes Agents—I：Tetralone Derivative from Juglans regia

A new compound,4-hydroxy-α-tetralone-4-O-β-D-[6‘‘‘‘‘‘‘‘-O-(3“,4“,5“-trihydroxybenzoyl)glucopyranoside(1),together with a known compound,4-hydroxy-α-tetralone(2),has been isolated from the roots of Juglans regia.2 showed moderate bioactivity against protein tyrosine phosphatase 1B(PTP1B).     

Second harmonic generation in some donor-acceptor ethylenes—I

We report the absorption spectra, oscillator strengths, ground state and excited state dipole moments, and molecular second order polarizability coefficients (β^CT) due to donor—acceptor charge transfer in four trisubstituted ethylenes, namely 1,1-bisdimethylamino-2-nitroethylene, 1,1-bispyrolidino-2-nitroethylene, 1,1-bispiperidino-2-nitroethylene and 1,1-bismorpholino-2-nitroethylene. The results are compared with that of trans-N,N-dimethylamino-nitroethylene, which has a large β^CT. The powder second harmonic generation (SHG) intensity of all these molecules is also measured and only 1,1-bispiperidino-2-nitroethylene is found to possess an efficiency of 20% of that of urea under the same conditions. The SHG efficiency of this compound and deficiency in the other molecules in the powdered state is discussed in terms of their arrangements in the unit cell. The crystal structure of the active molecule is also presented and the structure—property relationship is critically examined in all these molecules.     

WO_3 Anodic Oxide Film——I.Electrochromism and Auto-bleaching mechanism

Electrochromic and auto-bleaching processes at the WO2 anodic film in 0. 5 mol/L H2SO4 solution were investigated by cyclic voltammetry, a. c. impedance technique and photocurrent spectrometry. The colouration mechanism consists of hydrogen adsorption on the WO2 surface and the transport of H atoms in the WO, lattice. The bleaching process involves at least two steps: transport of interstitial H atoms and hydrogen desorption on the W surface, resulting in interstitial H+ ions; then extration of the H+ ions driven by the external electric field. The auto-bleaching arises from the hydroxylation due to both partial interstitial H atoms and a little of water contained in the film.     

尿酸质子转移反应的理论研究I——分子内质子转移研究

使用量子化学中的Hartree-Fock方法和密度泛函理论中的B3LYP方法，分别在3－21G^*和6－31G（d)水平上，计算了尿酸分子从三羰基异构体向三羟基异构体的转化。结果表明，转化过程经历了单羟基和双羟基异构体2种中间物和3种过渡态时的分子内质子转移（IPT），转移中的H原邻近的N，O和C原子形成了具有四元环结构的过渡态。随着IPT的进行，N－H键逐渐被削弱和断裂，O－H键则逐渐生成。3个反应的活化能分别为190.3kJ/mol,181.4kJ/mol和249.9kJ/mol(B3LYP/6-31G(d))。较高的活化能表明在室温下，无催化剂的IPT难以进行。     

聚酯基硫脲树脂PDTU—I对Ag（I）的吸附性能研究

测定了聚酯基硫脲树脂对银离子的吸附容量,讨论了吸附时间、溶液酸度,温度及银离子初始浓度等因素对其吸附性能的影响,并对吸附动力学和热力学进行了研究。结果表明,树脂对Ag(I)的吸附遵循G.E.Boyd液膜扩散方程和Langmuir等温式,且吸附为吸热过程。     

小功率空气冷却ICP-AES 研究I——小功率空气冷却ICP的特性

本文用顺序等离子体光谱仪研究了27.12MHz他激式R.F.发生器点燃的小功率空气冷却ICP的特性。测量并比较了二十个元素五十七条谱线在空气冷却和氩冷却两种ICP中的检测限。