细胞色素c在羟基磷灰石修饰玻碳电极上的直接电化学

采用沉淀法合成羟基磷灰石纳米晶体，由于具有独特的多吸附位点特征，羟基磷灰石可作为一种新型电子传递促进剂用于细胞色素c的直接电化学研究．在pH7．0的磷酸盐缓冲溶液中，细胞色素c在羟基磷灰石修饰玻碳电极表面于0．074V(vs．Ag/AgC1)处有一对准可逆的氧化还原峰，为细胞色素c血红素辅基Fe(Ⅲ)／Fe(Ⅱ)电对的特征峰．实验结果表明细胞色素c与羟基磷灰石之间的静电作用．促进了细胞色素c在玻碳电极表面扩散控制的准可逆单电子转移过程．讨论了电位扫描速度、溶液离子强度对细胞色素c直接电化学的影响．     

细胞色素C在离子液体修饰电极上的电化学行为

分别合成了疏水和亲水性咪唑类离子液体,并制备了相应的两种离子液体修饰的玻碳电极。循环伏安法测量结果显示,细胞色素C在离子液体修饰的玻碳电极上的电子传递过程为一扩散控制的准可逆反应,表明咪唑类离子液体也可用作细胞色素C电子传递的有效促进剂。电化学交流阻抗谱的测量结果得到了与循环伏安相同的结论。     

聚乙烯醇微透镜阵列的制备及其固载细胞色素c的直接电化学

利用自组装法以聚苯乙烯有序多孔膜为膜板制备聚乙烯醇微透镜阵列膜.在pH6.89的磷酸盐(PBS)缓冲溶液中,固载在聚乙烯醇微透镜阵列膜修饰的玻碳电极上的细胞色素c于0.072V(vs·Ag/AgCl)处显示一对准可逆的氧化还原峰,是细胞色素c血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰.考察了扫速、溶液pH及支持电解质浓度等因素对细胞色素c电子传递的影响,体系的表观异相电子传递速率常数k0为2.98×10-6cm·s-1.     

细胞色素C在4,5-二氮芴-9-酮修饰玻碳电极上的直接电化学研究

采用循环伏安法探讨了细胞色素C(Cyt C)在4, 5-二氮芴-9-酮(dafo)修饰玻碳电极表面的电化学行为.结果表明,Cyt C在dafo修饰电极上呈现一对峰形较好且准可逆的氧化还原峰,其式电位(E0′)为13 mV,峰电流与扫描速度呈线性关系,该电极过程是表面控制过程,电化学反应效率常数(ks)为0.89/s.固定在dafo上的Cyt C能促进H2O2的催化还原,响应快速而灵敏(<10 s),峰电流与H2O2浓度在5.0×10-6～3.0×10-4 mol/L范围内呈线性关系;检出限2.5×10-6 mol/L;米氏常数为1.07 mmol/L,显示出较好的亲和力.     

细胞色素C在单糖修饰金电极上的直接电化学

Hill等发现在4,4′-联吡啶存在时,细胞色素C在金电极上能进行准可逆的电化学反应。在研究细胞色素C的直接电化学过程中,人们又发现一些生物小分子如氨基酸、嘌呤等对细胞色素C的电化学反应有促进作用,但迄今未见有关糖类分子对细胞色素C电化学反应促进作用研究的报道。本文研究了5种单糖对细胞色素C电化学反应的促进作用。     

烟酸的电化学行为与测定

用循环伏安法研究了不同支持电解质溶液中烟酸的电化学行为。烟酸在玻碳电极表面有良好的电化学响应信号。在碱性介质中,烟酸被不可逆氧化,氧化产物具有电活性,可发生准可逆氧化还原反应;在酸性介质中,烟酸发生两步准可逆氧化还原反应。结合红外、紫外光谱分析,提出了烟酸在不同酸度的介质中的电化学反应历程。并根据－０．１３Ｖ处的氧化峰电流与烟酸浓度的关系,提出了电化学测定烟酸的新方法     

海藻酸钠水凝胶固载细胞色素c的蛋白膜伏安法研究

用海藻酸钠(SA)水凝胶将细胞色素c(cyt-c)固定在棱面热解石墨电极(EPPGE)表面,形成稳定的SA-cyt-c/EPPGE电极,采用蛋白膜伏安法(PFV)研究了cyt-c与电极之间的直接电化学和离子强度、pH、外加金属离子对其电化学行为的影响及其电催化性能。结果表明:cyt-c中血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对表现出准可逆行为,pH7.0、NaCl浓度为0.1 mol/L时电化学活性最高,外加金属离子则有抑制作用,SA-cyt-c/EPPGE可催化还原O2,有可能发展成为一种溶解氧的生物传感器。     

肌红蛋白-纳米氧化铝模板-金胶复合组装体的直接电化学与电催化

将肌红蛋白(Mb)固定在纳米氧化铝(AAO)模板-金胶复合组装体修饰玻碳电极表面,制得Mb/AAO/Au colloid/GC薄膜电极.在pH=5.4的HAc-NaAc缓冲溶液中,该薄膜电极于-0.21 V(vs.Ag/AgC l)处有一对准可逆的氧化还原峰,为Mb血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰.在AAO/Au colloid薄膜的微环境中,Mb与玻碳电极间的电子传递明显加快,该Mb/AAO/Au colloid/GC薄膜电极还可用于过氧化氢和溶解氧的催化还原.     

氯过氧化物酶-聚L-赖氨酸/GC电极的电化学特性

应用电化学方法在玻碳电极上修饰聚L-赖氨酸膜,以1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐做交联剂,固定氯过氧化物酶.修饰电极的循环伏安曲线呈现一对可逆的氧化还原峰,表明聚L-赖氨酸能够很好地促进氯过氧化物酶在电极表面的直接电子传递,这是一个受吸附控制并伴随有质子转移的准可逆电子传递过程.该电极有很好的稳定性,并能显著地电催化氧的电化学还原反应.     

双功能有机物修饰电极的修饰层结构对催化细胞色素C的电极反应的影响

用光谱电化学法研究了双功能有机物健那绿的电化学性质。在铂电极上,健那绿发生四步单电子传递过程。在健那绿修饰电极上细胞色素C的直接、非均相电子传递反应是准可逆氧化还原反应,电极反应速率常数K_s=4.17×10~(-4)cm/s。电极表面的修饰方法不同对细胞色素C的电极反应有很大影响。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。