A New 4.0-Generation Dendrimer Phosphorescence Labeling Reagent and Its Application to Determination of Trace Alkaline Phosphatase by Affinity Adsorption Solid Substrate-room Temperature Phosphorimetry

A Triton X-100-4.0G-D （4.0G-D refers to a 4.0-generation dendrimer） was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption （AA） reactions （direct method and sandwich method） were carried out between the labeling product of Triton X-100-4：0G-D-Wheat germ agglutinin （WGA） and alkaline phosphatase （ALP）, the product of AA reaction preserved the good characteristics of room temperature phosphorescence （RTP） of 4.0G-D and △Ip of the product was proportional to the content of ALP. According to the fact stated above, a new method for the determination of trace ALP by affinity adsorption solid substrate-room temperature phosphorimetry （AA-SS-RTP） was established on the basis of WGA labeled with the Triton X-100-4.0G-D. The detection limits were 0.20 ag·spot^-1 （corresponding concentration： 5.0×10^-16 g·mL^-1, namely 5.0×10^-18 mol·L^-1） for a direct method and 0.14 ag·spot^-1 （corresponding concentration： 3.5×10^-16 g·mL^-1, namely 3.5×10^-18 mol·L^-1） for a sandwich method, respectively. For their high sensitivity, good repeatability and high accuracy, the direct method and sandwich method have been successfully appfied to determine the content of ALP in human serum, and the results were coincided with the clinical detection results of the enzyme-linked immunosorbent assay method by the Zhangzhou Hospital of Traditional Chinese Medicine. Meanwhile, the mechanism for the determination of trace ALP by AA-SS-RTP was discussed.     

IR study of heterogeneity of OH groups in zeolite HY-splitting of OH and OD bands

We have been studying the problem of heterogeneity of OH groups in zeolites HY for a long time. The heterogeneity was suggested by the shift of the IR band of OH groups restoring upon ammonia desorption and also by the fact that the band of OH groups forming hydrogen bonds was relatively broad (broader than for homogeneous acidic OH). In the present study we present another important argument for heterogeneity: the splitting of the IR band of free OH and OD groups in a zeolite of Si/Al=8.3 dealuminated by (NH₄)₂SiF₆ treatment. Such a splitting is the best seen in low temperature spectra of OD groups. We found less acidic 3640 cm⁻¹ (AlO)(SiO)₂SiO₁HAl(OSi)₃ and more acidic 3625 cm⁻¹ (SiO)₃SiO₁HAl(OSi)₃ groups. The presence of these two kinds of hydroxyls corresponds to the presence of Si(2Al) and Si(1Al), respectively, detected in ²⁹Si MAS NMR spectra. We also found a small amount of strongly acidic 3599 cm⁻¹ hydroxyls interacting with extraframework Al species.     

Chemisorption of SO2 and Cl2 on indium oxide

The mutual influence of SO₂ and Cl₂ during their consecutive chemisorption on the In₂O₃ surface has been investigated. It was found that SO₂ is chemisorbed in the uncharged form, and the amount of chemisorption decreases as the temperature increases. The preliminary chemisorption of Cl₂ results in a dramatic decrease in the amount of SO₂ sorbed and in a change in the character of the bonding of SO₂ with the oxide surface. When SO₂ is sorbed first, the temperature of the formation of chlorides during subsequent chemisorption of Cl₂ decreases.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1718–1721, October, 1994.     

碱性水蒸气处理的ZSM-5沸石酸性质及孔结构的影响

 采用XRD，NH3－TPD，比表面积和孔结构测定等研究了在不同温度下用含10％NH3的水蒸气处理时HZSM－5沸石n（Si）／n（Al）＝25）酸性质及孔结构的变化规律．结果表明，随着处理温度的提高，HZSM－5的结构未发生明显的变化；样品的总酸量下降很快，但弱酸分布量相对提高，而强酸分布量相对下降；提高处理温度，样品的比表面积和微孔体积减小，二次孔或中孔体积及外表面积有增大的趋势．     

Electrooxidation Mechanism of Methanol at Pt-Ru Catalyst Modified GC Electrode in Electrolytes with Different pH Using Electrochemical and SERS Techniques

The electrochemical and in-situ surface-enhanced Raman spectroscopy （SERS） techniques were used to investigate the electrooxidation behavior of methanol in acidic, neutral and alkaline media at a Pt-Ru nanoparticle modified glassy carbon （Pt-Ru/GC） electrode. The results showed that methanol could be dissociated spontaneously at the Pt-Ru/GC electrode to produce a strongly adsorbed intermediate, CO. It was found that CO could be oxidized more easily in the alkaline medium than in the acidic and neutral media. The peak potential of methanol oxidation was shifted from 0.663 and 0.708 V in the acidic and neutral media to -0.030 V in the alkaline medium, which is due to that the adsorption strength of CO on the Pt surface in the alkaline medium is weaker than that in the acidic and neutral media. The final product of the methanol oxidation is CO2. However, in the alkaline medium, CO2 produced would form CO3^2- and HCO3^- resulting in the decrease in the alkaline concentration and then in the decrease in the performance of DMFC. Therefore, the performance of the alkaline DMFC is not Stable.     

Electrochemical behaviour of an indium electrode in concentrated KOH solutions at different temperatures

Summary The electrochemical behaviour of pure indium in KOH solutions (1–4M) was studied at different temperatures (25–70°C) by potentiostatic techniques. Two anodic peaks corresponding to the formation of In(OH)₃ and In₂O₃ were observed. The heights of the two peaks increased with the increase of alkali concentration. An increase of temperature increased the peak currents and shifted their corresponding potentials to more negative values. The variation of the peak currents and peak potentials with scan rate suggested that the anodic dissolution of indium was a diffusion controlled process. In cyclic voltammetry, the reverse scan consistently showed one peak which was attributed to the reduction of anodic oxidation products into indium. X-ray diffraction analysis confirmed the presence of In(OH)₃ at the first anodic peak, In(OH)₃ and In₂O₃ at the second anodic peak and In₂O₃ in the permanent passive region.

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Zum elektrochemischen Verhalten einer Indium-Elektrode in konzentrierter Kalilauge bei verschiedenen Temperaturen

Zusammenfassung Es wurde das Verhalten von reinem Indium in 1 – 4M KOH-Lösungen bei Temperaturen zwischen 25 und 70°C mittels potentiostatischer Methoden untersucht. Zwei anodische Peaks, entsprechend der Bildung von In(OH)₃ und In₂O₃, traten auf. Die Höhe der beiden Peaks wurde mit zunehmender Alkalikonzentration gesteigert. Eine Temperaturerhöhung verstärkte die Peakströme und verschob die entsprechenden Potentiale zu negativeren Werten. Die Abhängigkeit der Peakströme und Peakpotentiale von der Scangeschwindigkeit legte den Schluß nahe, daß die anodische Lösung von Indium in einem diffusionskontrollierten Prozeß stattfindet. Bei der cyclischen Voltammetrie zeigte der reverse Scan einheitlich einen Peak, der der Reduktion der anodischen Oxidationsprodukte zu Indium zugeschrieben wurde. Röntgendiffraktionsanalyse bestätigte die Präsenz von In(OH)₃ beim ersten anodischen Peak, In(OH)₃ beim zweiten Peak und In₂O₃ im permanent passiven Bereich.

     

K2O对Pt—Sn／Al2O3催化剂表面酸性及MCH脱氢稳定性的影响

利用吡啶吸附－ＩＲ，ＮＨ３吸附－脱附，原位热重积炭，ＤＳＣ等技术并结合甲基环己烷（ＭＣＨ）脱氢活性试验，研究了Ｋ２Ｏ对工业Ｐｔ－Ｓｎ／Ａｌ２Ｏ３催化剂的表面酸性及ＭＣＨ脱氢稳定性的影响，结果表明，Ｋ２Ｏ能有效地调变催化剂的表面酸性，降低其表面酸中心特别是强酸中心的数目；ＭＣＨ脱氢反应的积炭量随Ｋ２Ｏ含量的增加而减少，但催化剂的高温脱氢稳定性与Ｋ２Ｏ含量并不完全呈顺变关系，Ｋ２Ｏ含量应严格控制，当Ｋ     

Removal of H2S from Exhaust Gas by Use of Alkaline Activated Carbon

The purpose of this research was to select an activated carbon and alkaline solution blend that generated the best H₂S adsorption on alkaline-activated carbon. RB₂ (activated carbon) impregnated with NaOH solution was shown to have the optimum H₂S removal efficiency. The optimum NaOH concentration was 50 mg per gram of carbon. H₂S adsorption via RB₂-NaOH₅₀ was five times that of a corresponding fresh-activated carbon. The adsorption equivalent of H₂S is nearly 1 (mol-H₂S/mol-AOH), therefore, H₂S + AOH AHS + H₂O was the major reaction. The H₂S adsorption isotherm corresponded to the Freundlich isotherm.     

The Antiepileptic Lamotrigine and Its Analogues: Comparative Theoretical Electronic Properties

Electronic properties of lamotrigine (LTG) and two analogues (A1 and A2) are compared through MOPAC-AM1 calculations. Two stable conformers of LTG are calculated to exist in agreement with X-ray crystallography. In the three compounds and the two conformers for each of them, the more favorable protonation sites are N₂ and N₄; these should then be the sites appropriate for interaction with a receptor, and group valence reinforces the supposition. The molecular electrostatic potentials show that a region between the two chlorine atoms in LTG could be the site for an electrostatic interaction with a corresponding site in the receptor. The fluorine atom in A1 would play an equivalent role. A simple model for LTG-receptor interaction is proposed.     

N-丙基-N-[2-(2,4,6-三氯苯氧基)乙基]-1H-咪唑-1-甲酰胺的合成

以2，4，6-三氯苯酚和1，2-二氯乙烷为初始原料，在相转移催化剂十六烷基三甲基溴化胺和弱碱性助剂三乙胺存在下合成了N-丙基-N-[2-(2，4，6-三氯苯氧基)乙基]-1H-咪唑-1-甲酰胺，其结构经元素分析,IR，^1H NMR分析证实。并对该合成路线的反应机理进行了讨论。