Synthesis of a Tweezer—like Bis（Phenylthiapropoxy）calix[4]—arene as a Cation／π Enhanced Sensor for Ion—Selective Electrodes

Two novel 25,27-dihydroxy-26,28-bis(3-phenylthiapropxy)-calix[4]arene(3) and 25,27-dihydroxy-26,28-bis(3-phenylthiapropoxy)-5,11,17,23-tetra-tert-butylcalix[4] arene (4) were synthesized for the evaluation of their ion-selectivity in ion-selective electrodes(ISEs).ISEs based on 3 and 4 as neutral ionophores were prepared,and their selectivity coefficients for Ag^ (lg KAg,M^pot)were investigated against other alkali metal,alkaline-earth metal,aluminum,thallium(Ⅰ）,Lead and some transition metal ions using the separate solution method (SSM).These ISEs showed excellent Ag^ seletivity over most of the interfering cations examined,except for Hg^2 and Fe^2 having relative smaller interference(lg KAg,M^pot≤-2.1).     

Laser-hole boring into overdense plasmas measured with soft X-Ray laser probing

A laser self-focused channel formation into overdense plasmas was observed using a soft x-ray laser probe system with a grid image refractometry (GIR) technique. 1.053 &mgr;m laser light with a 100 ps pulse duration was focused onto a preformed plasma at an intensity of 2x10(17) W/cm (2). Cross sections of the channel were obtained which show a 30 &mgr;m diameter in overdense plasmas. The channel width in the overdense region was kept narrow as a result of self-focusing. Conically diverging density ridges were also observed along the channel, indicating a Mach cone created by a shock wave due to the supersonic propagation of the channel front.     

高能强子–强子碰撞中喷注性质的蒙特卡洛研究

在喷注“圆锥判定法”的基础上,对高能强子–强子碰撞中产生的喷注(微喷注)的性质进行了蒙特卡洛研究.采用以喷注动量为z轴的“喷注坐标系”,给出了表征喷注性质的各物理量在新坐标系中的分布情况.结果表明,圆锥判定法能够作为一种有效手段来对高能强子–强子碰撞和相对论重离子碰撞中发生的硬和半硬过程开展实验研究.由有喷注事件和无喷注事件的多重数分布可以看到,E_t=2GeV是用圆锥法确定喷注的合理的横能截断值.     

Spectrophotometric determination of microquantities of molybdenum

Summary A new spectrophotometric method for the determination of microquantities of molybdenum (VI) and rutin, respectively, has been described. In order to take all the advantages of this very sensitive method, the effect of some foreign ions on these determinations has been studied and a combined chromatographic-spectrophotometric procedure for the separation and the determination of microamounts of molybdenum (VI) in the presence of a large number of interfering ions has been developed.

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Spektrophotometrische Bestimmung von Mikromengen Molybdän

Zusammenfassung Eine neue spektralphotometrische Methode zur Bestimmung von Mikromengen von Molybdän(VI) bzw. von Rutin wurde beschrieben und der Einfluß einiger Fremdionen auf diese Bestimmung untersucht. Um die Anwendungsmöglichkeiten dieser Methode zu erweitern, wurde ein kombiniertes chromatographisch-spektrophotometrisches Verfahren zur Abtrennung und Bestimmung von Mikromengen Molybdän(VI) in Gegenwart einer größeren Zahl störender Ionen ausgearbeitet.

     

Curing theory of A_f-A_g type free radical polymerization (I)──Distribution function and its invariant property

ＴｈｅｔｈｅｏｒｙｏｆｎｏｎｌｉｎｅａｒｐｏｌｙｍｅｒｉｚａｔｉｏｎｗａｓｉｎｉｔｉａｔｅｄｂｙＦｌｏｒｙ[1]ａｎｄＳｔｏｃｋｍａｙｅｒ[2].Ｆｏｒｓｉｍｐｌｉｆｙｉｎｇｔｈｅｅｖａｌｕａｔｉｏｎｏｆａｖｅｒａｇｅｐｏｌｙｍｅｒｑｕａｎｔｉｔｉｅｓ,ｍａｎｙｏｔｈｅｒｓｔａｔｉｓｔｉｃａｌｍｅｔｈｏｄｓｓｕｃｈａｓｔｈｅｐｒｏｂａｂｉｌｉｔｙｏｆｇｅｎｅｒａｔｉｎｇｆｕｎｃｔｉｏｎｍｅｔｈｏｄ[3],ｔｈｅｌａｗｏｆｔｏｔａｌｐｒｏｂａｂｉｌｉｔｙｍｅｔｈｏｄ[4,5]ａｎｄｔｈｅｏｔｈｅｒｍｅｔｈｏｄｓ[6…     

Study on heterogeneous equilibria in saturated solutions of sparingly soluble diprotic acids

Heterogeneous equilibria in saturated solutions of sparingly soluble diprotic acids: 1,2-, 1,3- and 1,4-benzenedicarboxylic acid, and octanedioic acid, respectively, at ionic strengthI=1 (NaCl) and the temperature of 25 °C, have been investigated. The corresponding equilibrium constants were determined by the application of three independent methods: the formation function method, the method of protons bound to the acid in the solution and the solubility method. The results obtained by these three different methods are in good agreement.

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Untersuchung heterogener Gleichgewichte in gesättigten Lösungen schwerlöslicher diprotischer Säuren

Zusammenfassung Es wurden die heterogene Gleichgewichte in gesättigten Lösungen schwerlöslicher diprotischer Säuren (Benzol-1,2-, -1,3- und-1,4-dicarbonsäuren und Oktandisäure) bei einer IonenstärkeI=1 (NaCl) und der Temperatur von 25 °C untersucht. Die entsprechende Gleichgewichtskonstanten wurden mit drei unabhängigen Methoden bestimmt: mit der Methode der Bildungsfunktion, der Methode der an die Säure in Lösung gebundenen Protonen, bzw. mit der Methode der Löslichkeitsbestimmung. Die erhaltenen Ergebnisse stehen in guter Übereinstimmung.

     

Study of heterogeneous equilibria in saturated solutions of some sparingly soluble 8-hydroxyquinolines

Heterogeneous equilibria in saturated aqueous solutions of 8-hydroxyquinoline (A), 2-methyl-8-hydroxyquinoline (B) and 5-chloro-8-hydroxyquinoline (C) were investigated at constant ionic strength (1M sodium chloride), at 25.0 +/- 0.1 degrees , by the application of the following methods: the formation function method, the method of bound protons, the method of free proton sites and the solubility method. The following equilibrium constants were determined: K(s1)=[H(2)A(+)]/[H(3)O(+)], K(s2)=[HA] and K(s3)=[H(3)O(+)] [A(-)]. Their mean pK values are: -2.88, 2.42 and 12.09 for A, -3.27, 2.71 and 12.73 for B, and -0.34, 3.88 and 12.75 for C. In addition, the acidity constants of investigated 8-hydroxyquinolines were determined by pH-metric titrations. The values obtained for these constants were consistent with those calculated on the basis of corresponding equilibrium constants determined in heterogeneous systems.     

Shock-induced transformation of liquid deuterium into a metallic fluid

Simultaneous measurements of shock velocity and optical reflectance at 1064, 808, and 404 nm of a high pressure shock front propagating through liquid deuterium show a continuous increase in reflectance from below 10% and saturating at approximately (40-60)% in the range of shock velocities from 12 to 20 &mgr;m/ns (pressure range 17-50 GPa). The high optical reflectance is evidence that the shocked deuterium reaches a conducting state characteristic of a metallic fluid. Above 20 &mgr;m/ns shock velocity (50 GPa pressure) reflectance is constant indicating that the transformation is substantially complete.